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Content 1.

Application of Acoustic Emission Testing Technique in Health Assessment of Tank Bottoms of Crude Oil Storage Tanks: A Case Study in OIL

Sasanka Pratim Deka, CGM Field Engineering Chandan Kumar Das, DGM Field Engineering Wasim Saikia, Dy CE Field Engineering

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Energy Conservation Initiatives in Automobile Sector

Arunav Baruah, GM-Logistics

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3.

Human Factors and its Impact on Industrial Safety

Saroj Mistry, MSO Engineering Mine

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4. LED- The future of lighting

Anirban Kakati, DGM Electrical Sabbir Zaman, Sr. Engineer Electrical

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5.

Irrigation system of East Godavari District

Dhiraj Ch Bharali, DGM Civil

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6.

Different flow measuring methods in Production Installations of OIL -TECHNOLOGY & TREND

Nribir Choudhury, DGM Instrumantation Mirzanur Rahman, SE Instrumantation

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Process Safety Management

Biswajit Das, CE Electrical

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8. Cool Pavements

Bikash Sonowal, Dy. CE Civil Himangshu Bhuyan, Sr. Engineer Civil Kawshik Hazarika, Sr. Engineer Civil

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Partha P Boruah, Dy. CE Instrumentation Sriparna Bhowmik, Sr. Engineer Instrumentation

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10. Prospects of Instrumentation in Oil and Gas industry during the fourth industrial Revolution (Industry 4.0)

Gautam Buragohain, SE Instrumentation Kaustav Talukdar, Sr. Engineer Instrumentation Bidyut Bikash Sonowal, Sr. Engineer Instrumentation Dibyajyoti Baruah, Sr. Engineer Instrumentation Partha Pratim Bora, Sr. Engineer Instrumentation

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11. Plastic Road: Utilization of plastic wastes for construction of flexible pavement

Jyotismita Devi, SE Civil Mantresh Srivastava, Sr. Engineer Civil Sopun Borah, Sr. Engineer Civil

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12. Instrumentation and Control in Gas Compressors – A look at the present technologies and the future possibilities

Raunaq Barkakati, SE Instrumentation Rituballav Hazarika, SE Instrumentation Nibedita Baruah, SE Instrumentation

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13. Augmentation of electrical controls of drilling rigs in Oil India Limited - Journey till Now

Dwip Jyoti Goswami, Sr. Engineer Electrical Pragyan Thakuria, Sr. Engineer Electrical

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14. GREENER & LEANER Constraints and outlook in sustainable transportation

Kunal Anand, Sr. Engineer Logistics

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15. Deterioration of Concrete in Namrup BVFCL Plant - A CASE STUDY

Himangshu Bhuyan, Sr. Engineer Civil

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16. A Study on Possibility of Use of River Silt as Replacement of Natural Sand in Concrete

Tulika Das, Sr. Engineer Civil

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Control System Technology Upgradation of 20.28 MW Gas Turbine Generator

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Techsynthesis Application of Acoustic Emission Testing Technique in Health Assessment of Tank Bottoms of Crude Oil Storage Tanks: A Case Study in OIL Sasanka Pratim Deka, CGM Field Engineering Chandan Kumar Das, DGM Field Engineering Wasim Saikia, Dy CE Field Engineering Abstract: Crude Oil Storage Tanks invariably develop corrosion while service. To avoid development of any leaks to the tanks or to detect critical level of corrosion activity on tanks, it is mandatory to carry out inspection of the Crude Oil Storage Tanks at specific intervals. Oil Industry Safety Directorate (OISD) recommends Inspection Intervals of Crude Oil Storage Tanks as OISD Standard -129. The recommended interval of years as per the OISD guidelines for NDT Testing of Tank Bottoms Plates (internal Inspection) is 10 years of service. The prevalent practice in Oil India Limited (OIL) for Health Assessment of Tank Bottoms of Crude Oil Storage Tanks is Ultrasonic Thickness Measurement (UTM). Since to carry out UTM of tank bottoms, the tanks needs to be isolated from service and cleaned, “in service” tank bottom health assessment techniques were explored by OIL. OISD on their standard 129 also recommends that with corrosion based assessment of Tank Bottoms by “on stream” techniques like Acoustic Emission Testing (AET) / Robotic Measurements etc., the Internal Inspection Interval can be extended up to 15 years. Oil India Limited (OIL) adopted Acoustic Emission Testing (AET) for health assessment of Tank Bottoms of Crude Oil Storage Tanks in the year 2018 at a limited scale in 13 of Crude Oil Storage Tanks of various capacities at different location. Subsequently 02 Tanks (01 no 800 KL Capacity Tank and 01 No 10000 KL Capacity Tank) were taken up for Internal Inspection and Maintenance. Since AET results are indicative of extent of corrosion activity only, this paper tries to corroborate the results of AET with the actual Ultrasonic Thickness Measurement readings obtained during Internal Inspection of the above mentioned 02 tanks. This paper also tries to throw light on the principles, techniques of Acoustic Emission Testing (AET) along with its advantages over conventional NDT techniques. 1.0 Introduction: The Crude oil collected from various fields of OIL is stored in storage tanks for onward transportation of Refineries. For assessing the health of the Crude Oil Storage Tanks, periodical inspection is mandatory. Using prevalent practice of UTM in OIL, one can assess the health of Shell and Roof of the tanks only, while the tank is in service. For assessing the health of the tank bottoms by using UTM, one needs to isolate the tank from regular service, clean the tank before carrying out the NDT by UTM. Since this method is evidently time consuming, alternatives to this were explored and OIL opted for Acoustic Emission Testing Technique (AET) for health assessment of tank bottoms. OISD on their standard 129 also recommends that with corrosion based assessment of Tank Bottoms by “on stream” techniques like Acoustic

Emission Testing (AET) / Robotic Measurements etc., the Internal Inspection Interval can be extended up to 15 years. OIL adopted Acoustic Emission Testing (AET) for health assessment of Tank Bottoms of Crude Oil Storage Tanks in the year 2018 at a limited scale in 13 of Crude Oil Storage Tanks of various capacities at different location. Subsequently 02 Tanks (01 no 800 KL Capacity Tank and 01 No 10000 KL Capacity Tank) were taken up for Internal Inspection and Maintenance. 2.0 Limitations and Alternatives of Prevalent practice of NDT for Tank Bottoms: For carrying out health assessment of tank bottoms by using UTM the followings are mandatory: i. Isolation of Tank from regular service ii. Cleaning of the tank: a. Pumping out of residual crude oil from the tank

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Techsynthesis b. Evacuation of the sludge from the tank c. Final cleaning of the tank 2.1 Isolation of the tank from service causes Storage/ ullage issues and in Tank Farms of smaller capacitates such isolation might not be feasible at all. 2.2 Cleaning of the tank evidently involves quite a considerable amount time (say 3 months for a 10000 KL Capacity EFR Tank), such one can easily infer that preparatory works consume much more time than actual time for performing the NDT (UTM). 2.3 From the above it can be inferred that followings are the Limitations of Prevalent practice of NDT for Tank Bottoms: i. Isolation of the tank for a considerable amount of time. ii. Storage/ Ullage issues. iii. Considerable cost and time involvement for preparing the tank for NDT of the tank bottoms. 2.5 Alternatives to the prevalent practice were explored and the technologies were explored which can assess health of tank bottoms while the tank is in service, take less time and cost effective. Subsequently Acoustic Emission Testing Technique (AET) was adopted in OIL in the year 2018 at a limited scale in 13 of Crude Oil Storage Tanks of various capacities at different location. 3.0 Basics of Acoustic Emission Testing Technique (AET): Iron, in the presence of water, combines with atmospheric oxygen to form a hydrated iron oxide, commonly called rust, which is in turn termed as corrosion. Acoustic Emission Testing Technique (AET) predominantly assesses the extent of corrosion. During corrosion of steel volumetric change takes place, eg: during the corrosion process 1mm of steel corroding completely results in ~8mm of the hydrated iron oxide. This volumetric change inevitably results in multiple fracturing of the brittle oxide, and de-bonding of the layers of oxide from each other. The fracture and de-bonding results in the release of transient acoustic energy or “acoustic emission” (AE). Acoustic Emission Testing Technique (AET) process employs sensors placed on the tank shell to detect and record the “acoustic emission”, which is generated by the corrosion of the tank bottom

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plates. Moreover the AET can also detect the acoustic emission caused by cracks or discontinuities while the structure is stressed. The data recorded by AET Sensors are filtered, processed and the results grade the tank bottoms on the basis of severity of corrosion activity as below: Grade Description

Recommendation

I/A

No active sources of corrosion

No maintenance necessary for 5 years

II / B

Low active corrosion

No maintenance necessary for 3 years

III / C

Medium active corrosion

Maintenance / repairs to be carried out within 1 year

IV / D

Leaks and or high active corrosion

Immediate Maintenance / repairs to be carried out

Table-1: AET recommendations By corroborating the interpreted AE data with the available maintenance history, effective Maintenance Scheduling can be prepared. 4.0 Difference of AET over other NDT Techniques: Acoustic Emission is unlike most other nondestructive testing (NDT) techniques in two regards. The first difference pertains to the origin of the signal. Instead of supplying energy to the object under examination, AET simply listens for the energy released by the object. AE tests are often performed on structures while in operation, as this provides adequate loading for propagating defects and triggering acoustic emissions. The second difference is that AET deals with dynamic processes, or changes, in a material. This is particularly meaningful because only active features (e.g. crack growth) are highlighted. The ability to discern between developing and stagnant defects is significant. However, it is possible for flaws to go undetected altogether if the loading is not high enough to cause an acoustic event. 5.0 Advantages of AET for Health Assessment of Tank Bottoms: The followings are the envisaged Advantages of AET for Health Assessment of Tank Bottoms: i. It can be carried out while the Tank is in Service. ii. Since to external supply of energy to the object

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Techsynthesis under testing is required, the technique is intrinsically safe for Crude Oil Storage Tank applications.

7.1 AET data/ results for 800 KL Capacity crude oil storage tank:

iii. It can yield Instantaneous results, less time consuming. iv. Cost Effective. v. Not Labour Intrinsic. vi. It acts as a decision making tool to create a data base for maintenance scheduling. 6.0 Outline procedure for carrying out AET for Health Assessment of Tank Bottoms:

Fig-2: 3D view of Corrosion Map of 800 KL Capacity crude oil storage tank

The outline procedure for carrying out AET for Health Assessment of Tank Bottoms is listed below: i. Tank is isolated and allowed to settle for 12 -24 hours. ii. Sensors are attached to the tank wall around the entire circumference, ~1m above annular. One row, or two rows where condensation or high noise is possible. iii. The tank is monitored and data acquired, duration is ~1-2 hours. iv. The data is processed to eliminate unwanted noise. v. The result is graded per procedure.

Acoustic Emission Testing can be performed by ASNT –Level III certified personnel.

7.0 AET for Health Assessment of Tank Bottoms in OIL: As mentioned earlier, AET for Health Assessment of Tank Bottoms was adopted in OIL in the year 2018 and was carried out in 13 tanks. The data and results of the AET for 01 no 800 KL Capacity and 01 no 10000 KL capacity tanks are discussed here, since the same were subsequently taken up for Internal Inspection.

Fig-3: Corrosion Map of 800 KL Capacity crude oil storage tank Recommendation after data processing:

AET Sensor placed on tank shell

Fig-1: AET of in process

Table-2: Recommendation of AET results for 800 KL Capacity crude oil storage tank

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Techsynthesis 7.2 AET data/ results for 10000 KL Capacity crude oil storage tank:

in 7.0 above were corroborated with UTM data when the internal inspection of the tanks were carried out. 8.1 Data corroboration for for 800 KL Capacity crude oil storage tank:

Fig-4: 3D view of Corrosion Map of 10000 KL Capacity crude oil storage tank

Fig-6: Comparison of Corrosion Data- AET Vs UTM for 800 KL Capacity crude oil storage tank bottom The above shows no major deviation from the AET data, however the AET data shows a few localized pitting corrosions. Hence Pit gauging of the tank bottom was carried out and the data are compared as below:

Fig-5: Corrosion Map of 10000 KL Capacity crude oil storage tank Recommendation after data processing:

Table-4: Pit Gauging Reports for 800 KL Capacity crude oil storage tank bottom The locations for the indicated pitting are as below:

Table-3: Recommendation of AET results for 800 KL Capacity crude oil storage tank 8.0 Corroboration AET results with actual UTM Results: Since AET results are qualitative indicator of extent of corrosion activity to establish the efficacy of the AET technique, the result of AET of the tanks mentioned

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Fig-7: Locations of Pitting in 800 KL Capacity crude oil storage tank bottom If the locations are compared with the indications of AET as shown in Fig-3: Corrosion Map of 800 KL Capacity crude oil storage tank it is apparent that the AET data is of relatively higher accuracy.

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Techsynthesis 8.2 Data corroboration for for 10000 KL Capacity crude oil storage tank:

Fig-8: Comparison of Corrosion Data- AET Vs UTM for 10000 KL Capacity crude oil storage tank bottom The above shows no major deviation from the AET data.

9.0 Conclusion: The above discussion shows that AET data is accurate and reliable for assessing the health of the crude oil tank bottom plates. The AET data can be used as a decision making tool for chalking out maintenance schedules of crude oil storage tank in a quite reliable way. It is evident that AET results help to identify the tanks which require inspection and repair and leave others in-service until their condition indicates action is required. As a conclusion it can be inferred that, AET can be reliable, cost effective, safe and faster alternative to conventional NDT techniques as far as health assessement of Crude Oil Tank Bottoms are concerned.

Reference: a)

Literature for Physical Acoustics India Private Limited

b)

https://www.nde-ed.org/

c)

https://www.ndt.net/

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Techsynthesis ENERGY CONSERVATION INITIATIVES IN AUTOMOBILE SECTOR Arunav Baruah, GM-Logistics ABSTRACT The paper sheds light on the various energy conservation technology that are currently available in the automobiles. The paper briefly describes the various aspects of these technologies including the working principles, areas of application etc. and draws a comparison of these technologies with the contemporaries.

• Lack of precise control over the amount of injected fuel resulting in higher fuel consumption and lower power output • Failure to meet emission standards • Lower reliability due components

to

• No altitude compensation

The first automobiles were developed nearly two centuries ago and the mass production of automobiles has been going for more than a century. Although, automobile sector has been a very dynamic sector in terms of adoption of new and better technologies, the major push toward more efficient automobiles was driven by emission norms, environmental awareness and rising oil prices. The industry slowly moved from the noisy and smoky muscle car era to the present day smooth, efficient and low-emission cars. These changes have been facilitated by various technologies some of which will be discussed in this paper.

• Lack of diagnostics information

• Smart engines • Automatic transmission • Hydraulic axles

Remedial measure in SMART Engines • For meeting the stringent environmental norms, engines now have sophisticated electronic controls. Modern generation engines are also categorized as SMART engines (S- Specific, M- Measurable, A- Achievable, R- Reliable and T- Time-bound). • The manufacturer of SMART engine has brought certain changes in the basic engine model and also have introduced precise control over fuel injection quantity as well as timing of injection into the combustion chamber by incorporating various electronically controlled sensors and ECM (Electronic Control Module) which acts as heart of the engine

• Regenerative braking and hybrid vehicles SMART ENGINES • The effect of engine emission on the environment is considered to be a major concern all over the world .Various pollution creating agents like COx, NOx, etc. coming out of engine emission are considered to be major health and environmental hazard .They are also considered to be the most damaging elements so far as Ozone layer depletion is considered. The Problems with conventional engines are as follows:-

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moving

• Cold starting issues

INTRODUCTION

TECHNOLOGIES IN FOCUS

many

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Techsynthesis • The ECM controls the fuel delivery through a Common Rail Direct Injection (CRDI) system which ensures a high degree of fuel atomization and in turn efficient combustion. • Various other systems were introduce in SMART engines such as the Variable geometry turbocharger(VGT) , Exhaust gas recirculation(EGR), Diesel Particulate Filter (DPF), Selective catalytic reduction(SCR) etc. Advantages of Electronic control • Precise control over injected fuel and timing of delivery including multiple injections in the same cycle • Optimal combustion ratio • Increased altitude control because the injection is affected by the ambient as well as inlet air pressure AUTOMATIC TRANSMISSIONS Conventional transmission performance depends on the expertise of the driver. Improper gear shifts not only affect the fuel economy but also considerably affect the life of driveline components such as clutch, gearbox etc. Frequent breakdown of mechanical components is also common in conventional systems and is specially magnified in the case of driver abuse. Types of transmissions (CVT, Automatic & AMT) • The CVT which is also known as Single-Speed Transmission is an automatic gearbox which can change seamlessly through the continuous range of correct gear ratios and there is no clutch to change gears. The CVT is belt driven design to help change gears. • The AT is also called Auto or Self-Shifting Transmission or AGS (Auto Gear Shift) is a type of gearbox which automatically change gear ratios. The AT shifts gears by hydraulically locking and unlocking the system of gears and does not depend on a clutch to change gears. • The AMT, also known as SAT (Semi-Automatic Transmission) , is basically a manual gearbox in which gear shifting is done by electronic sensors, processors and actuators to engage the gears based on the input from the driver or by a computer.

Case study: Alison Automatic transmission The key difference between a manual and an automatic transmission is that the manual transmission locks and unlocks different sets of gears to the output shaft to achieve the various gear ratios, while in an automatic transmission; the same set of gears produces all of the different gear ratios. The planetary gear set is the device that makes this possible in an automatic transmission. The Allison Transmission 4700OFS (Oil Field Series) is part of the Allison World Series Transmissions. These models have 7 speeds with dual mode operation and many programmable features through the TCM. The main components of Allison Transmission are:







1. Torque Convertor and Lockup Clutch: Provides torque multiplication during high load requirements and acts as normal clutch during regular operation 2. Planetary gearsets and Clutch Packs: Responsible for shifting of gears and producing various gear ratios. 3. Retarder: Reduction of transmission output by applying hydraulic braking and thus enhancing the life of service brakes 4. TCM: Senses the inputs of various sensors and gives commands to various actuators to precisely control the gear shifts

Advantages of Automatic transmissions

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Techsynthesis HYDRAULIC LIVE AXLE Conventional Live axle technologies supply power to the live axle even during periods of low loading which results in extra transmission losses. Hydraulic axle can convert a dead axle to a live one as per requirement. Also the power going to the live axles can be precisely controlled using a hydraulic system. This results in better fuel economy

HYBRID VEHICLES hybrid vehicle uses two or more distinct types of power, such as internal combustion engine as well as an electric generator that powers an electric motor. The basic principle with hybrid vehicles is that the different power sources work better at different speeds and then switching from one to the other at the proper time during the speed transform, which in turn improves energy efficiency and fuel efficiency. Hybrid cars are classified according to the type of drivetrain or powertrain they feature, which determines how the engine and the motor work together to power the car. Series Hybrid

• The ECU of Hydraulic AWD system is connected to the CAN line and also has sensors through which it receives all the critical information such as Engine speed, Vehicle speed, Gear, Brake status, wheel speed etc. • When the switch is pressed, the pump gets coupled to the engine and starts pumping hydraulic fluid to the variable displacement radial piston motors which in turn produce torque and rotate the wheels • When the vehicle is stuck i.e the rear wheels are free-wheeling, the hydraulic motor produces high torque so as to match the speed to front and rear wheels. Once the vehicle starts moving, the ECU locks the front and rear wheels and hence front wheels copy the motion of their rear counterparts thereby allowing for easy turning. Advantages • Reduction in weight of the axle and on-demand AWD result in increased fuel efficiency • Ease in turning of the vehicle due to high turning angle • Ride height change not required(required earlier due to fitment of Transfer case)

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• In series hybrid, the electric motor handles all the driving and the gasoline engine only recharges the battery pack. When the driver starts the engine, power is received from the battery pack to the electric motor which turns the wheels. • The electric motor is charged by the battery pack or by the generator, which is powered by the gasoline engine. The gasoline engine in a series hybrid is not coupled to the wheels and does not directly power the car. • A controller in the transmission determines how much power is needed to propel the vehicle and whether to pull it from the battery or the generator.

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Techsynthesis Parallel Hybrid

• It uses both an internal combustion engine and electric motor. The conventional engine and electric motor are attached to one transmission which allows both of them to power the car at the same time. The fuel tank supplies gasoline to the engine while the generator charges the batteries. • When fuel travels to the engine or when the electric motor is turned on, the power that is generated propels the car. • A controller in the transmission determines when to operate the electric motor and when to switch to the gasoline engine. Regenerative Braking Both parallel and series hybrids feature a regenerative braking system, which both slows the car and recharges the battery. In a regenerative braking

system, the electric motor helps to slow the car down as you press the brake. The energy that is released from the wheels turns the electric motor, which acts as a generator and sends electricity back to the battery. CONCLUSION The introduction of the above described technologies has brought about a lot of change in the automobile industry in terms of emissions as well as efficiency. Newer technologies are emerging everyday and some of them have the promise to bring a paradigm shift in the mobility industry. Electronics are becoming more ubiquitous in the automobile industry and the developments in faster, cheaper and reliable electronics has been a major driver of adoption of mechatronics into conventional systems. The advent of newer and better materials, new sources of energy and advancements in electronic controls are ensuring that the automobile industry becomes even more dynamic that it ever was and aims for still lower emissions and higher efficiencies.

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Techsynthesis

Human Factors and its Impact on Industrial Safety SAROJ MISTRY, MSO Engineering Mine Abstract:

This article is about Human Factors that makes Supervisors and Managers around the world mad about the people in the work place use the easiest and shortest way, especially at the expense of SOP or Standard Operating Procedure and how we can tackle this to minimize Industrial accidents / incidents due to Conscious Based Decision Making Error. It is not always easy to find out the root cause of workplace accident or incident in industry. We generally blame human error for the root cause of most of the accident. However, further investigation likely to be revealed contributions of many other factors to any accident or incident in the workplace. If we evaluate the reciprocal actions of all the factors of the workplace i.e. people, workplaces and management systems –we can get a clear picture of the root element which drives the worker’s decision at the time of the accident. Here we will talk about basic element which drives people to use easy way or shortcut method skipping standard methods and which sometimes ends up with incidents or accidents. We spend endless hours working on SOP’s, develops safety practices for work force, which is reasonable and easy to follow. We train the workforce from the beginning, answering all quires. But sometimes later we see that, it didn’t work, they are not following SOP, and they make vital procedural lapses and cut corners or do in the easiest, cheapest, or fastest way. If we go deep into this, problem, we will find it as Expert Error of conscious based decision making. Reducing this error and influencing behaviour is the key learning in understanding HSE’s approach to human factors. “Human Factors discovers and applies information about human behaviour, abilities, limitations, and other characteristics to the design of tools, machines, systems, tasks, jobs, and environments for productive,

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safe, comfortable, and effective human use” (Sanders and McCormick, 1993) Human Factors refer to environmental, organizational and job factors, and human and individual characteristics, which influence behaviour at work in a way which can affect health and safety. It is not the cause of workplace accidents; it identifies error potential and the application of knowledge about human characteristics for improvement of design of the system to minimize potential error and its consequences. Once we can find the root causes which influences and drives worker’s decisions and actions, we will have the ability to take necessary measures to prevent repeated occurrence of the same. ‘Human behaviour is the responses of individuals or groups of humans to internal and external stimuli. It refers to the array of every physical action and observable emotion associated with individuals as well as the human race.’ Before understanding elements of human factor, first start with ABC of human behaviour where, ‘A’ stands for Activator which occurs prior to the behaviour. The activator or antecedent directs us prior to observable act i.e. what we do, which is the behaviour. ‘B’ stands behaviour. The behaviour ‘if we follow the SOPs’ is meant following the SOP and the behaviour ‘if we don’t follow the SOP’ is the cutting corner i.e. do in the easiest, cheapest, or fastest way and that is the observable act of the people. ‘C’ stands for the consequences. The consequences

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Techsynthesis have nothing to do with anybody else and as per as the behaviour goes, consequences happen to the particular person, who was doing the particular behaviour, whether following or not following the SOP. In most of the cases the activator definitely is the trigger that makes behaviour to follow and resulted consequences. But as we gain experience the consequences start to influence on our behaviour. The consequence themselves have certain attributes or characteristics which can be positive or negative, that can happen sooner or later, they can be certain or they can be uncertain. Any one of them absolutely can indulge motivate us. However, there are some of those characteristics that have more power than others. Let us have an example to get a clear picture on above: General SOP for electric shutdown procedure is as below:

1. Identify the feeder or equipment to take shutdown 2. Switch off the circuit breaker or CFS unit 3. Draw out Circuit breaker or take out Fuse 4. Lock the panel or switch fuse unit 5. Put danger board 6. Discharge the line with proper discharge stick 7. Short the line 8. Issue the permit to work

Now if the supervisor who is an expert, due to complacency or any other factor skip No. 3 or No.6 of the above list to finish the job faster or easier way (or cut corners) and if there is something wrong happens in the system, the person who will touch the line or test the line by naked hand (which generally done on dead line to re-confirm whether dead or alive) the consequence would be severe, effect would be negative, it will happen immediately and this would be definitely uncertain activity by the victim as the consequences was not anticipated by the victim. Though the SOP for this job was well known to supervisor or the technician but something drive him to demonstrate the behaviour of noncompliance of SOP and cut the corners with skipping line discharge with proper discharge stick.

Now to make it correct we can teach them again, we can make them accountable for the complacency or other way. But this may repeat again and again as the behavioural characteristics drive them cut corners. Sometimes we found peoples with behavioural characteristics of always choosing the faster and easier method or always remain in a hurry, without any pre considerations or judgments. Sometimes the consequences come out positive result or sometimes negative. When any accident happens we generally do better supervision and more discipline to prevent repeat occurrence. But in the case of human factor it will not work as it is something which is related behavioural error or decision based error of a particular individual and not a common thing. In the industry generally 60 to 80% people follow the same SOP without cutting corners. So there would not be any issue related to discipline or supervision. Benchmark SOP’s which is being followed by the people without using short cut method of faster method. Solution for those who generally do not follow the SOP, is to conduct training course for the whole work force and educate them about the expert error or about this decision based error, to make them understand why they use the easier or faster method and bypass the SOP. Re-examine the rest SOP’s for anything, which drives people to choose faster method and re designs that which is reasonable as well as easier to follow. Let us have an example where proper Standard Operation Procedure (SOP) may not be available or prove to be safe practices, where customized Safe Operation Procedure is more effective tool to reduce risk. Picture-1A (below) shows general practices of construction workers in any such work where SOP is not available or standard safety belt will not work. So they are working without using Safety Belt and always remain exposed to very high level of risk of fall accident without any basic protection. Any standard arrangement for safety to them would be highly expensive affair.

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Techsynthesis

In such cases the best solution is to make some arrangement so that risk on the worker can be minimized and supervisors or site engineers can avoid sleepless night. In this case construction workers can tie suitable rope on his waist and nearest firm structural beam or pillars keeping shortest length sufficient to perform his job as shown in Picture – 1B (below)

Considering risk level and unfavourable site condition for compliance of Standard Operating Procedure (SOP) we can modify it to reduce operational risk to minimum level, which can be accepted as Safe Operating Procedure (~SOP) Hence, it is the supervisor, who can convert noncompliance of SOP to beneficial for his worker’s safety

with innovative ideas, without affecting safety aspects to minimize risk factors. Check for the benefits of non-compliance of SOP without any damage to the safety standard and that could be on cost factors or on the time factor. Re-educated people about the changes of SOP’s and that’s benefit. Monitor on new modified SOP’s and collect feedback for further improvement. The elements of human factor have the potential for creating a vast range of reasons for why accidents occur in the workplace. Particularly when they added together lead workers to act in ways that make sense to them based on the resources and knowledge available. These are: Individual Factors: Knowledge, Expectations, Health, Fatigue, Age etc. Workplace and Equipment Design: Facility layout, Accessibility, Displays, Ease of use, etc.; Work Environment: Noise, Vibration, Lighting, Temperature, Chemical exposure, etc. Management: Organizations of work, Policies, Management decisions, etc. Job Design: Work schedule, Workload, Task design, Job requirements, etc. Information Transfer: Communication (written or oral), Instructions, Labels, Signs, etc. So to ensure workplace safety thorough investigation considering all elements of human factor is extremely beneficial and to get full benefit of that every major industry should have separate cell for investigation and Counselling Psychology to maintain a focus on facilitating personal and interpersonal functioning with particular attention to emotional, social, vocational, educational, health-related, developmental, and organizational concerns. Human factors interventions will not be effective if we consider these aspects isolation. Also Human Factor should, be included within a good safety management system as any other risk control system.

References:

Wikipedia http://www.hse.gov.uk/humanfactors/topics/fatigue.htm https://www.arbill.com/arbill-safety-blog/bid/180905/ https://www.youtube.com/watch?v=p-vfd4YOjeY

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Techsynthesis LED- THE FUTURE OF LIGHTING Anirban Kakati, DGM Electrical Sabbir Zaman, Sr. Engineer Electrical

Since creation of the light bulb by Thomas Edison, the world of lighting is currently crossing the most revolutionary times. With the advent of illumination for all and everywhere, the primary needs emerged from thriving for lower energy consumption, longer lamp life, smaller size and physical robustness. Being increasingly able to answer to these, the LED technology kept growing rapidly over past few decades and has now become the mainstay in illuminating commercial, industrial, public & domestic areas. Going ahead, it also encompassed the display systems, televisions, Human Machine interfaces, fields of aviation, automotive headlamps, or even advertising. However, there’s still is so much more that can be accomplished than simply providing illumination. Human-Centric LED Lighting: In sync with your mood

works with the natural circadian rhythms of human (wake and sleep cycle). Blue light, which is typically dominant in sunlight and LED helps to combat fatigue and creates an overall sensation of being awake by suppressing the production of melatonin, the body’s natural sleep hormone. On the other hand, LEDs can also produce Red-rich lighting having lesser blue content encouraging a sense of sleepiness by promoting production of melatonin. For example, this electronically controllable technology, tuned to appropriate blue or red-richness in a hospital, can help keep nursing staff alert during night shifts while also favouring relaxation in a patient’s room. The second and third types include dimmability and occupancy-based features. The LEDs would sense the ambient light in a room and accordingly adjust its brightness, thus having wide applicability in offices, retail stores, industrial warehouses and other similar utilities. Occupancy sensing can be achieved through motion or heat-sensing, both being extremely beneficial to individuals and the environment. Switching, dimming or turning off lights as and when needed, apart from adding to a company’s bottom line, also promotes curbing emission of greenhouse gases. IoT –Internet of Things

Human-centric LED lighting works in conjunction with natural rhythm of the human body creating the most effective and comfortable environment. This is accomplished in different ways. The first is color tuning which is different from other sources of light. LEDs typically guarantee a significant improvement in light quality because of its broad & smooth color spectrum similar to the sun’s rays. The color of light

The IoT, or the Internet of Things, refers to the ever-

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Techsynthesis growing network of devices coupled to the internet and communications occurring between Internetenabled devices and systems. How does this fit into with LED lighting? Since lighting is everywhere, an IoT enabled lighting simplifies the working of connected systems using sensors and microprocessors. Having an IoT enabled LED light in every room of a building can create an smart system with virtually unlimited capabilities to start, ramp up or down, or stop. In fact, the human-centric lighting mentioned earlier is most effectively implemented with IoT compatible lighting platforms. The same can also made to be the core of systems that optimize air conditioning and heating, grid management etc. LiFi – The newest addition Li-Fi is the upgraded version of Wi-Fi internet connectivity using light in place of radio waves (wireless optical) with seamless data transfer abilities, far lesser interference issues and at hundred times the speed! Li-Fi, integrated to the LED lighting

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systems vide a transmitter, creates an alternate path for internet connectivity in areas where internet connectivity is otherwise challenging. The uses and advantages of LED lighting thus extends its dominance to newer horizons in today’s techsavvy world. Apart from lowering the staggering demand of energy for illumination, this technology is set to meet your wide-ranged needs in future.

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Techsynthesis Irrigation system of East Godavari District Dhiraj Ch Bharali, DGM Civil

ABOUT THE EAST GODAVARI DISTRICT East Godavari District is a residuary portion of the old Godavari District after West Godavari District was separated in 1925. The East Godavari District is located in the North Coastal part of the state of Andhra Pradesh. The District boundaries are Visakhapatnam, West Godavari, Khammam Districts and Bay of Bengal. The District is located between Northern latitudes of 16o30’ and 18o 20’ and between the Eastern longitudes of 81o 30’ and 82o 30’. The District is known as rice bowl of Andhra Pradesh with lush paddy fields and coconut groves. It is also known as another Kerala, tourists to have a glimpse of its rich cultural heritage where the lush paddy fields swaying in the breeze appear to dance in a celebration to life. The Headquarters of the District is located at Kakinada. As the name of the district conveys, East Godavari District is closely associated with the river Godavari, occupying a major portion of the delta area. East Godavari district is having the area of 10,807 Sq.Kms. with 5 Revenue divisions, 60 Revenue Mandals and 1012 Grama Panchayats Topographically the district can be divided into three distinct regions. 1. Tribal area: The tribal area towards the northern part of the district, which is backward. There is an Integrated Tribal Development Agency (ITDA) for the welfare of the tribals, which also covers the health aspects.

Introduction to irrigation system of East Godavari District: The main reasons of economic development of the Delta Area are due to well designed Canal system. Irrigation is the sector which touches rural livelihood in terms of increased output of agricultural production. Economic development and poverty alleviation of the East Godavari district is the result of irrigated agriculture. The expansion of irrigation is widely believed to have played a major role in the region’s rapid agricultural growth over the last three decades ensuring economic agricultural prosperity in the dry regime. Keeping in view of the importance of irrigation for transformation of the rural economy, successive Governments have focused on expanding irrigation facilities in the East Godavari District. Water security is intimately tied with food security, livelihood, health, environment, economic development and overall well-being of the society. Water is a finite resource and managing water in days of rapid socio-economic growth and change is challenging. The water challenges for the state are, therefore, manifold – improving and safeguarding the existing drinking water supplies, managing water for irrigation, industry, power supply and environmental prevention of pollution.

2. The Uplands Areas: The upland area is sandwiched between the tribal and delta area. It is agrarian and depends on monsoon; therefore the crop losses are frequent and can be compared with backward Visakhapatnam District in the economy. 3. The Delta Area: It from the south part of the District and is irrigated by the canals of Godavari River. The areas are economically rich while compared with the development West Godavari District.

Paddy fields of East Godavari District

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Techsynthesis Irrigation system of East Godavari District:Towards the end of first half of previous century, the life in the two Delta regions had fallen into a sad case. The abolition of the East India Company’s factories (related to cloth trade) due competition from Manchester & European looms has drastically diminished the socio-economic conditions of the region. In 1832-33 a terrible famine has ravaged the area followed by three unfavorable years, 1835-36, 1836-37, 1837-38 followed by the calamities of 183839, 1839-40 and almost equally calamitous season of 1840-41. It is known as ‘Dokkala Karuvu’ (only ribs are seen without any flesh). It is said that one third of the population has perished during the same period. Later, while describing the above acute condition’s Lady Hope (daughter of General Sir Arthur Cotton) writes that children were sold for ‘Two Annas’ like other commodities in the farmers markets to survive. From the above statistics, we can easily conclude that before 1860, socio-economic condition of the people of East Godavari District was very sorrowful. Sir Arthus Thomas Cotton was a British General and Irrigation Engineer. Showing the poor economic status of the people of East Godavari district and in connection of revenue generation he devoted his life for the development of irrigation canal system at East Godavari District so that people can grow crops during famine also. He had put up a proposal to the then British East India Government for construction of anicut over the river Godavari at Dowleiswaram. The then Govt has responded to the above calamitous situation and deployed it’s ablest Administrators (Mr. Montgomerry) and Engineers (Sir Arthur Cotton) and provided the necessary Administrative sanctions for construction GDS (Godavari Delta System). The sanctions included major items like Anicuts across the rivers, Irrigation canals, Aqueducts, channels & sluices, flood banks, river training works, Roads and bridges etc. at Godavari Delta. The anicut was constructed with the initiative of Sir Arthur Cotton during 1857-62 to divert the water from the river to the Canal system. Godavari Delta System (GDS) is an established old Irrigation System in operation since 1862. The old anicuts consisted of anicuts in four arms of river Godavari near Dowlaiswaram with a crest level of

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+36.00 ft. and the irrigation potential originally envisaged in the year 1852 was 6.12 lakh acres. During 1862 to 1867, the crest of the anicut was raised to +38.00 ft. but the ayacut brought under cultivation by then was 4.36 lakh acres only. 2.00 ft. falling shutters were installed raising the crest level to +38.75 ft. in 1898 increasing the Ayacut to 6.40 lakh acres. Even this level was found inadequate to meet the rapid expansion of irrigation and during 1936 the Ayacut increased to 9.81 lakh acres with introduction of 3.00 ft. falling shutters. The anicut constructed by Sir Arthur Cotton has served the delta system for more than a century. Due to the increased water level on the anicut and ageing, the soundness of the structures deteriorated. Extensive damages took place to the left end of Ralli anicut during the floods of 1963. The Geophysical and Geotechnical investigations revealed that the anicuts are in a precarious condition due to undermining of foundations. Due to dilapidated condition of the old anicut, Sir Arthur Cotton Barrage (S.A.C.B.) was constructed during 1970 –1984 The pond level of Barrage is +13.64 M. The Godavari Barrage Project includes construction of new head sluices for all the three main canals with silt elimination measures in canals. The three main canals originating from the Barrage are:(i) Bank Canal (ii) Amalapuram Canal and (iii) Gannavaram Canal

Sir Atthur Cotton Barrage at Dowleswaram, Rajahmundry The Barrage consists of 4 Arms with 175 Bays with a

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Techsynthesis length of 3.599 Km . 1) Dowlaiswaram Arm with 70 Bays 2) Ralli Arm with 43 Bays. 3) Madduru Arm with 23 Bays and 4) Vijjeswaram Arm with 39 Bays. The barrage consists of 175 No. of vents for passing flood waters and 3 head sluices to supply irrigation supplies. There are 3 intervening embankments alignment of the barrage and the total length including islands is 5.837 Kms. The three Deltas get two crops ie., khariff and rabi. The present ayacut under Godavari Delta System is 10,13,161 acres spreading over 3 deltas in East Godavari and West Godavari Districts. Godavari Eastern Delta and Godavari Central Deltas are situated in East Godavari District. Godavari Eastern and Central Deltas abutting the Gowthami, Vasistha and Vynatheyam branches of Godavari river. Western Delta on the right side of Vasistha branch of Godavari River is situated in West Godavari District. Sl.No 1. 2. 3.

Delta Godavari Eastern (including Pithapuram Branch canal) Godavari Central Godavari Western Total

Ayacut in acres 2,81,303 2,01,896 5,29,962 10,13,161

There are 254 Kms length of main canals and 857 Kms of distributories, totally 1101 Kms length of irrigation canal net work is established to serve an ayacut of 1,13,842 ha. (2,81,303 acres) in Eastern Delta is spread over in 23 Mandals. There are 199 Kms length of main canals and 742 Kms of distributories, totally 941 Kms length of irrigation canal net work is established to serve an ayacut of 81,706 ha (2,01,896 acres) in Central Delta is spread over in 16 Mandals of East Godavari District. The Godavari anicut is, perhaps, the noblest feat of engineering skill which has yet been accomplished in British India. It is a gigantic barrier thrown across the river from island to island, in order to arrest the unprofitable progress of its waters to the sea, and to

Main canals of Godavari Delta Region spread them over the surface of the catchment on either side, thus irrigating land which has hitherto been dependent on tanks or on the fitful supply of water from the river or rainfall. Large tracts of land, which had been left arid and desolate and waste, were thus reached and fertilized by innumerable streams and channels. Peoples of East Godavari district believes that water flowing into sea as wastage and wants to conserve every drops of water. Due to increase in cost of construction of anicut over the River Godavari and the canal system, Cotton had to appear before a House of Common Committee to justify his proposal. According to Gautam Pingle, an Indian policymaker, the idea of interlinking of rivers in India to form a national water grid, an idea which had gained much attention from the Indian government and policy-makers at the turn of the 21st century, was in fact an idea that is more than 120 years old as it was first envisioned by Arthur Cotton. His work in India was much appreciated and he was honoured with KCSI (Knight Commander of the Order of the Star of India) in 1877. He became a much-revered figure in the state of Andhra Pradesh for his contribution in irrigating the area of land also known as Konaseema. Canal Water Regulation The broad principles followed for water regulation

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Techsynthesis were modified from time to time. The following are the general principles. 1. During Kharif entire ayacut is served with Irrigation depending on the availability of water. 2. Each major canal is having about five lock cum regulating structures. The number of such regulators and spacing of such structures is canal specific, based on topography and the service requirements. The FSLs of the canal is governed by commandability and navigation depth as well. Navigation started declining in the past five decades and has become almost non-existent today. Currently the driving head for drawal of water into various off takes in the respective reaches is the guiding principle for the level to be maintained. 3. In as much as the terrain is very flat (slope varies from 1:5000 to 1:15,000) and water table is shallow, paddy is the preferred crop followed by pulses and fodder crops. The drawal of quantities at head regulator is dependent on the stage of the crop. 4. Since transplantation period consumes a fourth of the total quantity of water, farmers are encouraged to complete it early to a. Attain sufficient height for the canopy of the crop, to sustain inundation during cyclone periods during NE mosoon (Oct-Nov). b. Take advantage of availability better supplies during the active period of monsoon. c. Get atleast two months canal closure period for executing O&M works for canals and drains 5. In respect of GDS, the lands were categorised as Permanent zone, rotational zone (triennial, biennial), excluded zones as a basis to decide the extents. Notwithstanding the rotational system followed earlier, the Rabi extents in each year is decided based on anticipated summer flows. The anticipated summer flows are forecast based antecedent monsoon flows together with the proposed releases from Hydroelectric units located in the upper reaches of the river.

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IRRIGATION POTENTIAL (A)District wise : (I) East Godavari District : a) Godavari Eastern Delta : b) Godavari Central Delta : c) Pithapuram Br Channel : Total :

2,45,333 Acres. 2,01,898 Acres. 32,507 Acres 4,79,736 Acres.

Drainage System Where there is a canal system, there must be a drainage system to be developed to cater excess water flowing from the paddy field after irrigation. The storms and depressions that develop in Bay of Bengal during monsoon season move across the coastal areas of Andhra Pradesh, causing heavy to very heavy rains. Andhra Pradesh has 1050 Km length of coastal line. This coast line, being the most cyclone prone zone in India was hit by about 90 cyclones since 1900 AD. According to one study, tropical storms originating from Bay of Bengal strike the densely populated parts of the Coast causing serious floods, causing misery to the inhabitants of the area, besides loss of life and loss to public and private properties. The storms and depressions on the East Coast of India are very frequent and severe in nature. They vary in size from 60 Km to 240 Km in diameter and have different intensities and core wind velocities sometimes reaching upto 325 Kmph. Nearly, 50 % of the storms on East Coast occur along the Andhra Coast causing very severe storm tides in the Krishna and Godavari Deltas. Excess runoff generated due to excessive rainfall for SW monsoon, NE monsoon and cyclone are generally catered by drainage system i.e. drainage system to be designed for excess water after irrigation based on the catchment area and for the excess runoff due to monsoon and cyclone.

Teki Drain leading to Bay of Bengal

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Techsynthesis The boon and the bane of Aqua Culture Tail end deprivation is common to all the Irrigation systems. The additional suffering to the tail end farmers in these two systems is water logging, salinity and exposure to cyclones. To mitigate such suffering the farmers in the fringes of the two deltas have started converting the irrigated lands into fish ponds from the year 1978 and now it works as a major economy. It generates revenue for the large part of the population of East Godavari district.

Fish ponds developed at East Godavari District Conclusion:The Sir Arthur Cotton Museum has been built in his honour in Rajahmundry, Andhra Pradesh. The museum holds approximately one hundred images and 15 machine tools that Cotton used when constructing the barrage in Andhra Pradesh from 1847 to 1852. He is known as the “Delta Architect” of

the Godavari District because of his pioneering work in irrigation engineering. People of East Godavari district offer puja to Sir Arthur Cotton for giving life to the people of delta region of East Godavari District. Similar kind of project may take up by Assam Government also by construction barrage in small rivers and by developing irrigation system in the catchment area of that river which will definitely increase the per capita income of the people of Assam. According to the 2012-13 provisional estimates, the per capita annual income of Andhra Pradesh was Rs.41,593. Table below shows the East Godavari District per-capita Income from 2004-05 to 2012-13 which is much higher than the per capita income of India. Per-Capita Income of the East Godavari district S.No. Year Rupees 1 2004-05 31,411 2 2005-06 29,236 3 2006-07 33,076 4 2007-08 36,040 5 2008-09 38,096 6 2009-10 38,885 7 2010-11 37,611 8 2011-12 39,331 9 2012-13 41,593 Source: Socio-Economic Survey of Andhra Pradesh, 2013-14

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Techsynthesis Different flow measuring methods in Production Installations of OIL -TECHNOLOGY & TREND Nribir Choudhury, DGM Instrumantation Mirzanur Rahman, Supdt. Engineer Instrumantation Abstract: In this paper, we are going to summarise the trend of development of various technologies and standards for flow measurements and chronology of adoption of those in Oil India Limited. It also includes the basic advantages and disadvantages of various techniques of flow measurements in general and challenges in reference to OIL. Introduction: Flow measurement can be defined as the quantification of movement of a fluid. The flow measurement is assumed as the oldest recorded work in the field of instrumentation. Fluid flow is one of the most vital parameter of measurements for any production process. In Oil India Limited, being an E&P company, application of fluid flow measurement plays a vital role in operation and production. Fluid flow measurement encompasses a wide variety of fluid, and to meet the requirements, instrumentation industries, over many years developed a wide variety of flow measuring instruments. Acceptance, adoption and industrialization of different techniques are influenced mostly by the development of internationally accepted standards for flow measurements. Trend and development of flow measuring standards: It is very important to have a uniformity of information to avoid the differences in measurement of any parameters. This leads to formulation of various standards for measurements and day-to-day upgradation of such standards. For example, a chronology of development of AGA (American Gas Association) and API (American Petroleum Institute) standards for flow measurements is as below: • 1930, the AGA issued Report AGA-1 to cover the use of DP flow meters with orifice plates for custody transfer applications

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• 1955, AGA 3 for orifice flow meter issued • 1975, API adopted AGA 3 • 1976, API MPMS 5.3 Measurement of Liquid Hydrocarbons by Turbine Meters • 1981, AGA-7 for turbine meters, was published. • 1998, AGA 9 for ultrasonic flowmeters was published. • 2002, API approved the use of Coriolis flowmeters in custody transfer • 2003, AGA 11 for Coriolis flowmeters was published. • 2005, API MPMS 5.8 Ultrasonic Flow Meters Using Transit Time Technology, 1st edition issued Different industries, as per their requirement and applicability adopted different technologies; however it is mostly influenced by availability of standards for that. With the changing pace of technology and standards, like the other organisations, Oil India Limited also adopt various flow measurement techniques over the period of time. A brief description of different methods for flow measurement in OIL is as below. Different flow measuring method in Production Installations of OIL Orifice Meter: When an orifice plate is inserted in a flow line, a pressure drop proportional to flow occurs across the plate. Flow can be measured by measuring this drop in pressure using a differential pressure measuring instrument. In OIL, we are using mostly orifice meter for gas flow measurements and to some extent also for water flow measurements. Orifice as the primary device may be in the form of orifice flange, single chamber orifice/ junior orifice and dual chamber orifice/senior orifice. The basic advantage of single chamber orifice system

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Techsynthesis with advancement of technology and requirement presently we are also using single chamber and double chamber type orifice meter.

is that without removing the flange, orifice plate can be changed, but we have to stop the flow through it. In case of dual chamber orifice plate can be changed without stopping the flow. Major advantages of orifice metering are • Works in gas, steam, and liquid applications. • Is insensitive to fluid conductivity. • A well designed orifice can be extremely accurate, especially if the meter uses designed meter run and temperature and pressure compensation. • Orifice meters do NOT have a low flow cut off • Orifice meters do not require direct fluid flow calibration Major disadvantages of orifice metering are • The square relationship between differential pressure and flow greatly limits the turndown of most orifice meters. The pressure drop rises quickly as the flow increases. • The permanent pressure drop of most orifice plates is about two-thirds of the measured differential pressure • Orifice meters are sensitive to installation. The length of the meter run, the location of the transmitter, the method of running the impulse lines, and several other items can greatly impact their accuracy.

Two pen chart recorder as secondary device is very old pneumatic device which is still in use in OIL because of its two distinct advantages- No electric power is required which make it very convenient to use in remote area operation and readings are quite acceptable for our internal use. Presently there are also electronic differential pressure transmitter (along with pressure and temperature transmitter) and multivariable transmitter/ flow computer as secondary device with orifice for better accuracy. A simple comparison chart for the three devices is given below: Secondary device with orifice meter: Two Pen DP Transmitter Chart Recorder

MVT/ Flow computer

Accuracy of DP unit + 0.5 to + 0.75 %

• Stability: + .05% of URL per year over 5 years • Differential Pressure Accuracy: .05% of span • Static Pressure Accuracy: .05% of span

• DP reading accuracy: ±0.05% • Rangeability: 100:1 • Stability of 0.25%: up to 10 years

Turbine Flow meter: Turbine Flow Meter is a volumetric type flowmeter. The flowing fluid engages the rotor of the turbine meter causing it to rotate at an angular velocity proportional to the fluid flow rate. The angular velocity of the rotor results in the generation of an electrical pulse in the magnetic pickup coil associated with the meter. The summation of the pulsing electrical signal is related directly to total flow. Turbine meters have the following characteristics:

With normal care in installation, the measurement accuracy of orifice meter is ±1 % which is acceptable for our in house applications. By following AGA-3 and AGA-8 standards, the average accuracy can be achieved up to ±0.1%. For most of our installations, we are primarily using flange type orifice as primary device. However,

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Techsynthesis • Accuracy of 0.25 percent of rate with repeatability of 0.10 percent is typical. • Rangeability typically varies from 7:1 to 75:1, depending on meter design, fluid viscosity, and meter size. • A high flow rate for a given line size is obtainable. Line velocity may be as high as 8 to 9 meters (25 to 30 feet) per second. • Very low flow rate designs, as low as 0.02 liters (0.005 gallons) per minute (although normally nonlinear in these ranges) are available. • Availability of very wide temperature ranges and pressure ratings. • Turbine meters are available for bi-directional flow (as a special design). Limitations Turbine meters: • Susceptible to wear or damage if process stream is dirty or non-lubricating. • Require considerable maintenance. For calibration require to send to manufacturer/ to a special facility • Relatively high cost. • Strainers are required • Turbine meters have unique relationship between accuracy, rangeability, viscosity, and meter size. • Susceptible to damage from over speed. Turbine flow meter in use a) M/s Rockwin make DN 250 G 1600 along with online GC(M/s Daniel make 575) and Flow computer(M/s Daniel make 600+) Accuracy: + 1% (min to .2 of Max flow), + 0.5% (.2 of Max flow to Max flow) Repeatability: + 0.1%, Rangebility: 1:20 b) M/s Rockwinmake WTM Series Accuracy: + 0.5%, Repeatability: + 0.1% Ultrasonic Flow meter: Ultrasonic flowmeters use sound waves to determine the velocity of a fluid. There are mainly two types of ultrasonic flow meter-transit time and Doppler type. In Doppler type, frequency shift of transmitted wave is calculated which is proportional to flow rate while

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in transit time type, the difference between upstream and downstream propagation time is calculated to determine the flow rate. In production installation of OIL, we are using transit time ultrasonic flow meters. Ultrasonic flow meters have the following characteristics: • Include no moving parts • High accuracy and turndown ratio • Practically no pressure drop • Can measure fluid like heavy crude • Advanced models with full diagnostic suites that make calibration easier and reduce measurement uncertainty Limitation of ultrasonic flow meter: • High initial cost • Dirt in fluid impact performance and measurement accuracy • Sonic noise may interfere • Build-up on the inside pipe walls can reduce inside diameter of pipe and affect measurement accuracy Ultrasonic Flow meter in use a) M/s Daniel make 3400 series, along with Online GC and M/s Denial make Flow computer FlowBoss 600+, Repeatability: + 0.05%, Rangebility: 1:30 b) M/s GE make Portable Ultrasonic Flowmeter: for liquid application Clamp on Transducer: For 2” to 24” pipes, Pipe Wall Thickness Up to 3 in Pipe Materials All metals and most plastics Flow Accuracy Pipe ID>6 in: ±1% to 2% , Pipe ID< 6 in: ±2% to 5% Repeatability ±0.1% to 0.3%, Range (Bidirectional):–12.2 to 12.2 m/s

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Techsynthesis Coriolis Meter The basic operation of Coriolis flow meters is based on the principles of motion mechanics. It consist of a vibrating tube and when a fluid passes through this tube the mass flow momentum will cause a change in the tube vibration, resulting in a phase shift. This phase shift can be measured and a linear output derived proportional to flow.

In general Coroilis flow meters have the following characteristics: • Accuracy of the flowmeter is typically ±0.2% of full scale. • Rangeability is 80:1, Repeatability is as high as ±0.05%. • Line sizes are from 6 mm to 200 mm (¼ inch to 8 inch). • Availability of very wide temperature ranges, from -204°C to +204°C (-400°F to +400°F) and pressure ratings (up to 330 bar or 5000 psig depending on size). • Coriolis technology provides direct mass measurement independent of changing fluid properties, therefore, temperature, pressure, viscosity and specific gravity compensation is not required. • Can be used to measure, the density, volumetric flow rate • Upstream/downstream straight piping not required. Limitation of Coroilis meter: • Sensitive to external environmental changes (pressure and temperature changes). • Sensivity to piping vibration. • Relatively high weight (about 80 kg, for 2” size flowtubes) • Relatively high pressure drop. • Relatively high cost. • Meters for hazardous application are costly.

Coroilis Flow meter in use for crude oil flow measurement application a) M/s Micromotion make Model no. CMF300M & CMF400M, Transmitter Model no. 3700 For liquid: Mass/volume flow accuracy: ± 0.1%, Density accuracy: ±0.0005 g/cm3 For Gas: Mass/volume flow accuracy: ± 0.25%, Density accuracy: ±0.0005 g/cm3 Note: Accuracy depends on turn down ration also Challenges: • Day to day technology advancement is very fast and in case of instrumentation it is even faster. To keep efficiency, accuracy, availability and maintainability of existing system and adoption of new technology is a challenging task for us, which is also true in case of flow measurements. • Presence of crude oil in gas and gas in crude oil as impurities is a problem associated with oil and gas flow measurement. If the percentage of these impurities increases beyond a level, the accurate measurement of the desired fluid flow becomes a challenge. • Due to dynamic nature of production, sudden increase or decrease of fluid flow in a particular line or change in composition over a period of time may make the existing flow measuring device unsuitable on account of rangeability etc. • Most of our existing installations are old and any modification required for up gradation or installation of a new (flow measuring) system is very difficult. • As all new technology based measurement systems are electronic based, so it requires an uninterrupted stable power, which is also a challenge to get in all production installation. • Remote geographical location where we are operating is hindrance for getting quick service from outside parties in case of emergency. • To adopt a new technology and to get the maximum benefit, the knowledge level of the user and also the maintenance team required to be updated and to be trained.

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Techsynthesis

• Fiscal metering is another challenging area which is basically a combination of regulations, laws, protocols, systems and devices which enables two parties to transfer and measure the product/item from one side to another in a way that both sides agree on. Complexity of custody /fiscal metering increases in terms of accuracy with consistency and calibration requirement.

Conclusion: Considering the applicability, accuracy demand and cost effectiveness, currently we are using various flow measurement techniques from simple orifice plate to state of the art technology like Ultrasonic flow meter and Coriolis mass flowmeter. In spite of various challenges, we have to cope up with technology advancement and have to keep a balance between older and newer technology for optimization.

References: 1. 2. 3. 4. 5. 6.

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Operation &Maintenance manual • Barton 202 two pen chart recorder • Rosemount MVT 3051 • Cameron Scanner 2000 • Rockwin DN 250 G 1600 & WTM series www.emerson.com, www.instrumentationtoolbox.com, www.automationforum.com, www.wikipedia.com, www.slideshare.com.

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Techsynthesis PROCESS SAFETY MANAGEMENT Biswajit Das, Chief Engineer (Electrical) ‘Process Safety’ and ‘Personnel Safety’ are separate items in safety management. A sound personnel safety performance of an organisation is not enough to deal with the inherent risks of the hazardous processes, especially in the oil & gas industry. Investigation reports of major accidents show that relying mainly on the low personnel injury rate as a safety indicator is misleading. Personnel safety indicators rarely provide a true picture of the level of safety in the plant. Process Safety Management (PSM) is a systemlevel approach towards control of process hazards to avoid incidents and protect people, asset and environment. PSM demands proactive and systematic identification, evaluation, and prevention of process hazards. Incidents like a slip, trip, fall, cut, etc. usually affect one or two individuals, whereas incidents for failure of process safety are likely to affect many people on-site and offsite. Failure in process safety may lead to disastrous consequences and can cause multiple injuries and fatalities along with substantial environmental damage. Piper Alpha accident (1988), BP’s Texas City Refinery explosion (2005) and Deepwater Horizon drilling rig accident in the Gulf of Mexico (2010) are few examples from the long list of process safety failures in the global oil and gas industry. Compared to personal safety, the frequency of the process safety incident is low. But severity of the process safety incident is often extreme, which puts questions on the sustainability of an organization. Post 1984 Bhopal gas tragedy, United States in 1992 come up with OSHA PSM Regulation (29 CFR 1910.119) aimed to prevent accidental release from the hazardous process industry to protect employees and nearby community. Process Safety Management comprises the following 14 elements, which are interlinked to some extent. All these elements need to be addressed properly in a hazardous process plant following the applicable OSHA standard. Such comprehensive regulation for implementation of PSM system is yet to come up in India. PSM requires technical knowledge and in-depth engineering expertise in the process and training. In PSM, responsibility for hazard controls is mostly in the hands of senior management and engineers. Proactive safety culture is the backbone of PSM. Regular PSM

PSM Element

OSHA Standard

1

Employee Involvement

1910.119(c)

2

Process Safety Information

1910.119(d)

3

Process Hazard Analysis

1910.119(e)

4

Operating Procedures

1910.119(f)

5

Training

1910.119(g)

6

Contractors

1910.119(h)

7

Pre-Startup Safety Review

1910.119(i)

8

Mechanical Integrity

1910.119(j)

9

Hot Work permit

1910.119(k)

10

Management of Change

1910.119(l)

11

Incident Investigation

1910.119(m)

12

Emergency Planning and Response

1910.119(n)

13

Compliance Audits

1910.119(o)

14

Trade Secret

1910.119(p)

compliance audits are mandatory as per regulation and shall be conducted by the person knowledgeable of the process. Knowledge, skill and attitude of O&M personnel need to be checked periodically. A wellimplemented PSM system should be able to anticipate risks, rather than reduce/eliminate the known risks. Though the Indian Oil & Gas industry is quite seasoned in conventional HSE management system but it is mostly limited to occupational HSE, personal safety, fire safety, Emergency Response and Disaster Management Plan (ERDMP) etc. In the absence of regulatory obligation, implementation of PSM like a holistic approach is not compulsory in India. Indian Oil & Gas industry is over 70 years old. Many assets possessed by the NOCs are old. Apart from technical up-gradation of old plants, with new policies of the government, there are huge investments in the O&G sector. Works are going on for many new projects. The use of new technologies and automation in modern process plants is obvious. Sophistication comes with a high level of instrumentation and technical complexity. Adoption of the PSM system proactively is the need of the hour looking at a brighter future. At the design stage of the plant, it is essential to eliminate or minimize hazards rather than control hazards afterwards.

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Techsynthesis Cool Pavements Bikash Sonowal, Dy. Chief Engineer Civil Himangshu Bhuyan, Sr. Engineer Civil Kawshik Hazarika, Sr. Engineer Civil A SOLUTION: COOL PAVEMENTS

THE PROBLEM Like conventional dark roofs, dark pavements get hot in the sun because they absorb 80-95% of sunlight. Hot pavements aggravate Urban heat islands or UHI by warming the local air, and contribute to global warming by radiating heat into the atmosphere pavements can aggravate urban heat islands because they comprise about one third of urban surfaces. Hot pavements can also raise the temperature of storm water runoff. What is the Heat Island Effect (UHI)? The elevated temperature in urban areas as compared to rural, less developed areas is referred to as the urban heat island effect. There are many reasons for UHIs. When houses, shops, and industrial buildings pavements are constructed close together, it can create a UHI. Building materials are usually very good at insulating, or holding in heat. This insulation makes the areas around buildings warmer.

Solar reflective “cool” pavements stay cooler in the sun than traditional pavements. Pavement reflectance can be enhanced by using reflective aggregate, a reflective or clear binder, or a reflective surface coating. Cool pavement is a road surface that uses additives to reflect solar radiation unlike conventional dark pavement. Technology: Cool pavements can be made from traditional paving materials: 1. Cement concrete

• Can be modified by use of white cement, or cement blended with light colour slag.

2. Asphalt concrete

• Can be modified by use of light-coloured aggregate, coloured asphalt by pigments or sealant, or using tree resin in place of asphalt, light-coloured coating, or chip seals, white topping, ultra-thin white topping (UTW) and micro surfacing with light-coloured aggregate etc

3. White topping (light coloured), Coating of asphalt pavements. 4. Resin based pavements etc... A small experiment: To check the practicality of the concept of cool pavement a small experiment was conducted. A small patch (0.5m x 0.5m) of a black topped road was painted (white colour). Temperatures were than checked for the black topped road and painted patch with a temperature gun for few days.

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Techsynthesis

Fig 1: - Painted patch, Loc- Jorajan OCS approach road.

Fig: 3 Temperature Chart

The results were quite encouraging considering the fact that the road was just coated with a simple white paint. Now imagine the results with a proper coating over a widespread area. Potential Benefits: Day 1 Temp recorded – 30.9 ◦C Time – 1.20 pm

Day 1 Temp recorded – 28.5 ◦C Time – 1.20 pm





Day 2 Temp recorded – 29.5 ◦C Time – 1.20 pm

Day 2 Temp recorded – 27.7 ◦C Time – 1.20 pm

The experiment was conducted for 1-week i.e. from 16.11.19 to 23.11.19 daily at 1.20 PM noon. Date, Time - 1.20 Pm, Location Jorajan

Black topped ◦C

White painted road Temp ◦C

Temp Difference ◦C

16-Nov

30.9

28.5

2.4

18-Nov

29.5

27.7

1.8

19-Nov

31.2

29.9

1.3

20-Nov

27.7

26.8

0.9

21-Nov

31.5

30.5

1

22-Nov

29.7

28.9

0.8

23-Nov

30.2

29.4

0.8

Fig:2 Temperature, Time and date data









1. Energy savings and emission reductions: Cool pavements lower the outside air temperature, allowing air conditioners to cool buildings with less energy. Cool pavements also save energy by reducing the need for electric street lighting at night. 2. Improved comfort and health: Cool pavements cool the city air, reducing heat-related illnesses, slowing the formation of smog, and making it more comfortable to be outside. 3. Improved air quality: By decreasing urban air temperatures, cool pavements can slow atmospheric chemical reactions that create smog. 4. Reduced street lighting cost: Cool pavements can increase the solar reflectance of roads, reducing the electricity required for street lighting at night. 5. Increased driver safety: Light-coloured pavements better reflect street lights and vehicle headlights at night, increasing visibility for drivers. 6. Slowed climate change: Cool pavements decrease heat absorbed at the Earth’s surface and thus can lower surface temperatures. This decrease in surface temperatures can temporarily offset warming caused by greenhouse gases.

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Techsynthesis Potential Costs: Cool pavement costs will depend on many factors including, but not limited to, the following -





CONCLUSION:



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• Current status and near future researcher & development outcomes of technologies; • Its sustainability if used on a massive scale and potential application barriers; • The region; • Local climate; • Contractor; • Time of year; • Accessibility of the site; • Underlying soils;

• Project size; • Expected traffic; • The desired life of the pavement.

Besides the benefits and costs listed above, the benefits and costs considerations should include environmental, social, and economic aspects, rather than just the economic one. The general initial construction cost for cool pavement might be higher than that for regular conventional pavement. However, life-cycle assessments (LCA), including lifecycle cost assessments (LCCA), can help in evaluating whether long-term benefits can outweigh higher upfront costs.

Engineering Conference, 2019

Techsynthesis CONTROL SYSTEM TECHNOLOGY UPGRADATION OF 20.28 MW GAS TURBINE GENERATOR Partha Protim Boruah, Dy. Chief Engineer Instrumentation Sriparna Bhowmik, Sr. Engineer Instrumentation Abstract: The modern world is characterized by rapidly changing technology where computer systems, software, phones and other devices are state of the art one day and on the verge of obsolescence in within a few years’ time. Technology is always changing, which creates opportunities as well as challenges hand in hand. New devices and software can help us do our jobs better and faster, but upgrading costs money. This paper documents the Upgradation of Control System of 20.28 MW Gas Turbine Generator of Duliajan Power Station, why this upgradation was required at this stage and feasibility and cost-benefit analysis of the available options for upgrade. In addition, we have discussed about the benefits and system improvements achieved from the upgradation and how the extended lifecycle of the new control technology will lead us to save valuable time and cost in the future. Introduction: The 20.28 MW GTG of Duliajan Power Station runs on Mark VI Control System, which is a proprietary of M/s General Electric. The Mark VI Control System is a Triple Modular Redundant (TMR) microprocessor based control system. The Mark VI Control System broadly comprises of the following components:

• • • • • •

Control Panel – Mark VI GT Control panel Controller Card – UCVGH1A Communication Card – VCMIH2C Input/output Cards (I/O) Power Distribution Module (PDM) Human Machine Interface (HMI)

is approximately 10 years, followed by parts and services support and eventual replacement upgrade. This lifecycle can be divided into three phases. In Phase I, the primary product is in Factory Production and is released to market with full support including enhancements, custom modifications, new spare parts and repair services. In Phase II, the product goes to Post Production stage and is no longer available for new installations. New spare parts are still available, and repair, exchange, and refurbishment services are available through designated Control Solutions repair centers. At the end of Phase II, approximately one year before transitioning to Phase III, the Last Time Buy Notice is issued by the OEM, which is intended to update the customers on the obsolescence of the particular product and to advise them of the available options for maintenance and support of the affected control systems. Phase III is the Legacy phase in which the product is no longer fully supported and new spare parts are no longer manufactured. The parts & support for the product are limited to the available resources and components. The Controller Card of the Mark VI Control System i.e., the UCVGH1A controller, entered into Legacy Phase III in October, 2014 as per GE Notice. The following chart shows the history of lifecycle of the GE Mark series:-

Section 1 Major factors which led to the Upgradation of Control System 1. Lifecycle of GE Mark Control Systems The lifecycle of a GE turbine-generator control system

As it can be seen from the above chart, the complete Mark VI control System moved into the Legacy Phase in 2019. The Last Time Buy Notice for all Mark VI products was published by GE in December 2018.

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Techsynthesis 2.

End of Life of Microsoft Windows XP

The Human Machine Interfaces (HMIs) of the Mark VI Control system were Microsoft Windows XP based Operating Systems. The tools used for configuring, loading, and operating the Mark VI system included the Control System Toolbox (toolbox), CIMPLICITY HMI operator interface, and the Turbine Historian which were based on Windows XP. In December 2014, Microsoft had declared the End of Microsoft Support for Windows XP based Operating Systems. It also advised its users to upgrade the affected systems to the latest available Windows OS. Hence, HMIs with Windows XP OS, their spares and technical support were no longer available after 2014. Based on the above two scenarios, the following summary of the status of the existing system was prepared:

• Controller UCVGH1A and Mark VI Control System – Entered Legacy Phase III – No new spares were available and no opportunity for Last Time Buy. Failure of Controller card would have led to failure of entire Control system and in turn, the 20.28 MW Gas Turbine Generator.



• Windows XP based HMI – End of Microsoft Support – No spares and support services available from Microsoft. In case of failure of the HMI processors, we could not have monitored and controlled any plant parameters and the starting and stopping of the Gas Turbine.

View above, it was decided to go for the Upgradation of the Control System of the 20.28 MW GTG from Mark VI to Mark VIe (Enhanced) after taking recommendation and consulting with the OEM and a detailed feasibility study and cost-benefit analysis of the possible options for upgrade. The Mark VIe (Enhanced) Control System The Mark* VIe control system is a flexible platform used in multiple applications. It features high-speed, networked input/output (I/O) for simplex, dual, and triple redundant systems. Industry-standard Ethernet communications are used for I/O, controllers, and supervisory interface to operator and maintenance stations, as well as third-party systems.

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The ControlST* software suite, which contains the ToolboxST* toolset, is used with Mark VIe controls and related systems for programming, configuration, trending, and analyzing diagnostics. It provides quality, time-coherent data in the controllers and at the plant level for effectively managing control system equipment. The Mark VIe Safety control is a stand-alone safety control system for safety-critical applications. It also uses the ControlST software suite to simplify maintenance, but retains a unique set of certified hardware and software blocks. Analysis of the Possible Options for Upgrade The two possible options that came up were as follows: • Upgradation of complete panel from Mark VI to Mark VIe (Enhanced) Control System • Migration from Mark VI to Mark VIe (Platform Upgrade) Upgradation of Complete Panel from Mark VI to Mark VIe is a full panel to panel replacement, including the Human Machine Interfaces (HMIs). This includes complete removal of the Control Cabinet and replacement with the new system. This job is time consuming in nature and the system downtime would have been approximately one month. The cost of the complete upgradation process would have been Rs. 6.36 Crores (approximately) as per quotation from the OEM. Moreover, this upgradation would have rendered few existing mandatory spares for the Mark VI system of worth Rs. 3.44 Crores, of no use. So the total expenditure of the full panel upgradation would have been approximately Rs 9.8 Crores. Introduction to Platform Upgradation/Migration of Control System To provide their customers with minimum system outage timeline, more flexibility and support options, M/s General Electric came up with Platform Upgradation or more commonly known as ‘Migration’ of Mark VI to Mark VIe Control System. It is a smart and efficient alternative to the Full Panel to Panel Upgrade. The Mark VI to VIe migration delivers significant performance enhancements and an improved control system lifecycle. This migration allows existing Mark VI to be retrofitted with Mark VIe control without having to remove the entire Mark VI system and

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Techsynthesis fully replace it with a Mark VIe system. The existing Mark VI cabinets (including auxiliary cabinets) are retained. The migration kit provides Mark VIe control with the computational power able to execute the advanced control algorithms for turbine control. The kit provides an easy path to port Mark VI application code to Mark VIe application code. This minimizes the affected hardware and allows for a quick changeout of the hardware to minimize installation costs. The new Control system maintains the current I/O capability. The cost of Migration of Control System is much less as compared to the full panel to panel upgrade. As per the OEM, the total cost of Migration including both materials and services is approximately Rs. 1.95 Crores. And the Migration of Control System would have also allowed us to use few of the existing spares (worth Rs 87 Lakhs approx.) as mentioned earlier, as all the components of the Control Panel are not replaced in Migration, unlike complete panel upgrade. Hence, the Migration of system would cost us approximately 2.82 crores, which much lesser than what it would have cost us in a Full upgradation. SECTION 2 Migration Job at Duliajan Power Station GTG-3 Mark VI to VIe migration activities started on 04th September 2019. The MARK VI controllers, VCMI & Protection racks were replaced as a part of MARK VIe migration. The Migration works were completed on 9th September 2019, and the 20.28 MW GTG was finally synchronized on 14th September 2019. The following are the key activities performed during the Migration job:

• 3 nos. existing UCVGH1A controllers – Replaced with 3 nos. new UCSB controllers • 3 nos. VCMI communication interface card – Replaced with 3 nos. PCMI communication card • VPRO over speed protection assembly and TPRO terminal board – Replaced with PPRO protection assembly • The two HMIs in the Control Rooms and one spare HMI were replaced with new Windows 10 based HMIs.

Fig: New Mark VIe UCSB controller

Benefits derived from the Migration to Mark VIe system The Mark VIe control system provides performance, operability and reliability with the benefit of: • I/O expandability • Increased computational power • Intuitive HMI features • Accurate Turbine Screens • A dedicated Startup Sequence Page- to monitor the critical parameters of the Turbine essential for Startup • Convenient Navigation • Alarm Management • Live & Historical Trending & Easy Data Analysis of all the parameters Unlike the previous versions of the GE Mark Control Systems, the Mark VIe control system has been designed and developed by M/s GE for an extended lifecycle through a modular structure. This allows for incremental technology upgrades, obsolescence protection and comprehensive system upgrades without replacing the entire system. While it is very necessary to keep up with the pace of changing technology to remain competitive in the market, it is also important to efficiently use our existing resources and create a balance between time, cost and benefits derived from any particular process. Upgrading to a smart and reliable system like Mark VIe, has leveraged the new generation controller technology, and at the same time has provided a feasible and cost effective solution to us. References: (i)

GE fact sheet GEA-S1288A – Mark VIe Control – Design for Extended Lifecycle (ii) GE Product Life Cycle Support Notice – GE LCN-CS007-05 (iii) GE Product Life Cycle Support Notice – Update – GE LCNCS004-02 (iv) Mark Vie Control Product Description – GEA-S1300B

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Techsynthesis PROSPECTS OF INSTRUMENTATION IN OIL AND GAS INDUSTRY DURING THE FOURTH INDUSTRIAL REVOLUTION (INDUSTRY 4.0) Gautam Buragohain, Supdt. Engineer Instrumentation Kaustav Talukdar, Sr. Engineer Instrumentation Bidyut Bikash Sonowal, Sr. Engineer Instrumentation Dibyajyoti Baruah, Sr. Engineer Instrumentation Partha Pratim Bora, Sr. Engineer Instrumentation

Abstract: Everyone is talking about Industry 4.0. But what exactly does the term mean? Industry 4.0 refers to the fourth industrial revolution and it is the concept of factories in which machines are augmented with wireless connectivity and sensors, connected to a system that can visualize the entire system and make decisions on its own. Introduction: In an Oil & Gas industry instrumentation plays a vital role in increasing productivity by optimizing the process plants. In addition to that, instrumentation also plays a critical role in increasing safety and reducing pollution, making instrumentation a significant part of the Oil and Gas industry. With the recent advances in the semiconductor technology coupled with the enhanced computing powers; the sensors, controllers, actuators, communication protocols are becoming highly intelligent day by day. The Fourth Industrial Revolution (Industry 4.0) is creating a paradigm shift in global growth and driving demands for energy products. This brings huge future prospects in the field of instrumentation and automation. The oil and gas industries are embracing the emerging technologies to become smarter, more efficient, and sustainable and taken initiatives to implement new technologies to exploit massive opportunities the technologies can bring. The evolution of Industries is as follows: Industry 4.0 describes the trend towards automation and data exchange in manufacturing technologies and processes which include cyber-physical systems (CPS), the Internet of Things (IoT), Augmented Reality (AR), Big Data, Artificial Intelligence (AI), etc.

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One of the major aspects of Industry 4.0 is that the cyber-physical systems communicate and cooperate with each other and with humans in real-time. This enhances human capabilities to execute various jobs as well as increase productivity, efficiency as well as safety of a factory/industry/process plant. The latest state of the art technologies which are expected to revolutionize the Oil and Gas industry are to be discussed in this paper are: a) b) c) d)

IIoT (Industrial Internet of Things) Artificial Intelligence Big data and analytics Wireless technology

• IIoT (Industrial Internet of Things) The Internet of Things (IoT) is a network of internetconnected objects able to collect and exchange data. The Internet of Things (IoT) is a system of interrelated computing devices, mechanical and digital machines, objects, animals or people that are provided with unique identifiers and the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction. A complete IoT system integrates four distinct components: sensors/devices, Connectivity, Data processing, and Actuators/User interface. The IoT

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Techsynthesis sensors/devices will “talk” to the cloud through some connection protocol. Once the data gets to the cloud, software processes it and then might decide to perform an action, such as adjusting the actuators or send an alert to the user via e-mail, text or alarm. For the O&G industry, the advantages of oil and gas IoT applications lie in creating value through an integrated deployment strategy. IoT will allow the industry to digitize, optimize, and automate processes that were previously unconnected to save time, money, and increase safety. According to McKinsey, “the effective use of digital technologies in the oil and gas sector could reduce capital expenditures by up to 20 percent; it could cut operating costs in upstream by 3-5 percent and by about half that in downstream.” • Artificial Intelligence (AI) In the oil and gas industry, there are two primary applications of the technology: Machine learning and Data Science. Machine learning enables computer systems to learn from and interpret data without human input. Within the oil and gas industry, this allows companies to monitor complex internal operations and respond quickly to concerns that human operators may not have been able to detect. Data science uses AI to extract information and insights from data, using neural networks to link related pieces of data together and form more comprehensive pictures from existing information. The offshore oil and gas industry can use AI in data science to make the complex data used for oil and gas exploration and production more accessible, which allows companies to discover new exploration opportunities or make more use out of existing infrastructures. The Oil and Gas Authority (OGA) of UK has launched the oil and gas National Data Repository (NDR) in March 2019. The NDR contains 130 terabytes of geophysical, infrastructure, field and well data. The NDR uses AI to interpret this data, in which the OGA hopes will uncover new oil and gas prospects and enable more production from existing infrastructures. This data covers more than 12,500 wellbores, 5,000 seismic surveys and 3,000 pipelines.

• Big data analytics Big data analytics is the often complex process of examining large and varied data sets, or big data, to uncover information such as hidden patterns, unknown correlations, market trends and customer preferences that can help organizations make informed business decisions. Currently, along with other fields, these technologies are introduced to the oil and gas industry. Big data technologies can augment traditional methods in developing a deep understanding of the oil and gas operations to address the challenges faced by operators in a holistic way. From the information technology perspective, the development of large datasets has allowed industries to transform the way the automation has been applied, enabling real-time monitoring and control of operations. Digital field technologies play an important role in the big data analytics. Philosophy of the digital field is the principle of “measure-model-decidefulfill-and-control”. Instrumental basis of the digital fields consists of sensors. The sensors installed in the oil wells enable the distributed measurement of temperature, pressure and other critical parameters which can help the oil industry to a new upliftment of production. Information is transferred from these sensors to the focal points of the digital fields – realtime control center or to the monitoring center. Developing fiber-optic systems for real-time collection and transfer of geological information from the fields, production and technological data processing in the monitoring centers, real-time 3D visualization of processes and the process data, and the introduction of robotic technology provide remote control of the operations and remote services. • Wireless technology Wireless technology is new to industrial applications. The comparison between wireless and wired instrumentation system is in terms of features and cost-saving. Industry 4.0 is based on constantly enhancing the technology that we have actually used in the past. Industry 4.0 modern-day innovations are driving big changes in wireless technology. With the industrial internet of things (IIoT), businesses are able to improve productivity, effectiveness, and success via wireless sensor networks (WSN).

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Techsynthesis Built-in roaming capabilities are valuable in automation applications with remote locations, such as the oil and gas industry. Wellheads and pipelines are typically found in isolated and hard to reach areas. It can be tough to find road access for most of these places. While today’s technology makes it possible for operation in these remote areas without the demand for individuals in the field, there are most likely going to be instances where the pipes or wellheads need repairs because of buckling, leakage or various other broken components. Wireless machine-to-machine (M2M) communication options deliver smart wellhead surveillance as well as control options to support optimal manufacturing, accurate telemetry, and also fault-tolerant interactions. With a versatile M2M communications architecture that delivers protected, end-to-end, high-speed wired and wireless communications for supervisory control and data acquisition (SCADA) networks, new broadband networks will perfectly connect to remote operations, such as wellheads and pipelines. Oil and gas operators can leverage modern mesh technology to develop a course from the field site to the control center with market conventional routing methods to increase network performance. Prospects of Instrumentation during Industry 4.0: In the Industrial 4.0 Instrumentation technologies are entering a phase of major change. Sensors are transformed from traditional wired to wireless. Wireless Instrumentation is a competitive technology in cases where there is need to remotely monitor instrument condition, remotely reconfigure instrument amd monitor process data to optimize performance. Data collecting from sensors are much more cost effective than ever because sensors are battery powered and wireless. Because of Wireless sensors capital expenditure for new project and installation cost as well as execution & maintenance time drastically reduced. Sensors connect to high level Software platform, available both at onsite and offsite. Onsite connection is often via a local intranet, creating IIoT. Internet makes offsite connections with cloud based storage. Wireless sensors accompanying analytics improves plant performance, increase safety, and show very

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fast Return Of Investment (ROI). An example uses wireless acoustic transmitters at a refinery to improve regulatory compliance and cut hydrocarbon losses by $3 million annually with timely detection and repair of faulty valves. The project paid for itself in five months; estimated ROI was 271% annualized over 20 years. SWOT analysis of Oil India Limited with reference to the 4th Industrial revolution: SWOT stands for Strengths, Weaknesses, Opportunities, and Threats. It is a powerful tool for study to identify its internal strengths and weaknesses, as well as its external opportunities and threats by an organisation to develop a business strategy or guiding an existing company. Strengths and weaknesses are internal to the company. It consists of the things that we have some control over and can change. Opportunities and threats are external to the company, things that are going on outside the company, in the larger market. We can take advantage of opportunities and protect against threats, but we can’t change them. Here, we are going to undertake a SWOT analysis of the implementation of the new technologies fuelled by the Fourth industry revolution (Industry 4.0) in Oil India Limited. SWOT ANALYSIS Strengths

Weaknesses

• Dynamic & diversified millennial workforce. • Experience across decades. • Wide geographic presence. • Well established infrastructure – ERP, Desktop Central, DRIVE

• Lack of Interoperability between the instruments of different processes. • High CAPEX requirement migration to new technology. • Incompetent workforce with regard to the latest technology.

Opportunities

Threats

• Digital India initiative of Govt. of India. • Future proof – enhanced interoperability across platforms • Tapping into new markets – renewables • Expediting explorations in logistically challenged areas • Energy efficient and environmentfriendly. • Improved digitalized archiving • Efficient audits.

• Unpredictable global regulations for fossils fuels. • Nascent stage for cybersecurity & privacy – Stuxnet, Wannacry • Execrable statutory standards worldwide.

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Techsynthesis Necessity of implementation of the Industry 4.0 in Oil India Limited: The business benefits of implementation of technologies introduced by Industry 4.0 are immense. The technologies will assist to enhance human capabilities in the following aspects: • Better decision making • Optimize internal business operations. • Reduce headcount through automation. However, this will result in giving rise to some new challenges like: • It’s hard to integrate new projects with the existing processes and systems.



• Technologies and expertise are too expensive. • There are not enough people with the expertise in the technology.

The implementation of the new technologies is a necessity in a company like Oil India Limited (OIL) to be vibrant and to be competitive in the ever challenging E&P market. However, before selection and adoption of a new technology or a process, a thorough study to be carried out to ascertain its requirement, usability, maintainability, lifecycle and of course the cost benefit. During the process we have also to consider the facts that main productivity of OIL is mainly dependent upon brown fields (matured fields), situated at logistically hostile regions.

References: 1) The concept of the Industry 4.0 in a German multinational Instrumentation and control company: A case study of a subsidy in Brazil, 15.03.2018 by Renato Mana, Francisco Ignácio Giocondo Cesar, Ieda Kanashiro Makiya and Waini Volpe.



2) https://www.automation.com/automation-news/article/the-4th-industrial-revolution-industry-40-unfolding-at-hannovermesse-2014.



3) https://en.wikipedia.org/wiki/Industry_4.0.



4) Artificial Intelligence for the real world by Thomas H. Davenport and Rajeev Ronanki (published in Harvard Business Review)



5) Industrial Internet of Things and Industry 4.0 from Emerson Process Management (Re-Printed from Control Engineering June 2015)

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Techsynthesis Plastic Road: Utilization of plastic wastes for construction of flexible pavement

Jyotismita Devi, Supdt. Engineer Civil Mantresh Srivastava, Sr. Engineer Civil Sopun Borah, Sr. Engineer Civil Abstract: In this era of industrialization, a huge amount of plastic wastes are being generated every day. These wastes are not only being generated by industries but also by households in the form of MSW. This MSW and ISW solid waste management has become very essential due to the existential threat that it possess towards the environment. According to CPCB (Central Pollution Control Board), India generates approximately 26000 tonnes of plastic waste per day, which is about the weight of 9000 matured Asian elephants. Proper disposal and utilization of this humongous waste has become very important not only due to its land and water pollution, but also due to the unavailability of required number of landfills. Even live stocks are not spared. Three thousand cows died in Lucknow in the year 2000, whose cause was found to be plastic in their stomach. Apparently the bags had been ingested as the animals grazed at dump sites. With more than 35 tons of plastic waste generated by every Indian state, India is in every keen need of a solution to get rid of this plastic waste problem. However, recent researches and applications have found that plastics can be substituted as an additive in flexible pavement construction. The field tests withstood the stress, and proved that plastic wastes used after proper processing as an additive, would enhance the life of the roads and also solve environmental problems which is the need of the hour [1]. Key Words: i) MSW: Municipal Solid waste, ii) ISW: Industrial Solid Waste, iii) PCA: Plastic coated aggregate Introduction: Since its inception plastic has turned out to a blessing and a curse at the same time to mankind. Due to its lighter weight and versatility, it is extensively used in manufacturing and packaging sector. Single use plastic which counts for upto 40% of the plastics in the world has turned out to be a major evil for this modern society. This single use plastic has a usable life of merely few minutes and after which it either turns up in a landfill or disposed off into the water bodies, like rivers, lakes, seas & oceans. After reaching the sea, some of the wastes break into smaller particles, also known as micro plastics, while the other rests in the sea-bed. The Great Pacific Garbage Patch is one of the outcomes of this process. Even the highest peaks of the world, the grasslands, and valleys have also been affected by these wastes. Millions of aquatic and terrestrial animals die due to ingestion of such plastic waste. Hence the world is in the dire need of a concrete solution to curb these wastes by re-using or re-cycling. Various alternative solutions were put forward to reuse and recycle such plastic and use of single use plastics in flexible pavement construction

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is one of them. In construction of flexible pavement, bitumen is used a binding material that holds the aggregate together by forming a bitumen film around them. Although bituminous flexible pavements are strong, but they are susceptible to water and a greater wear and tear takes place in regions of heavy rainfall. However, addition of organic synthetic polymers like rubber and plastics improves the quality of bitumen and they are emerging as one of the important construction materials for flexible pavement [2]. In regions of heavy rainfall, like North-east India, construction of plastic roads can be considered as an effective alternative to replace the conventional bituminous flexible pavement. Scope of study: This is a comprehensive study of plastic roads which incorporate the aspect of plastic road construction methodology as well as various field test result to evaluate the improved performance of plastic road pavement. Literature Review: R. Vasudevan et al. (2010) found that when shredded plastic is heated upto 130-1400C, plastic polymer

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Techsynthesis gets softened without evolution of any gas. When these polymers are blended with aggregates at a temperature of 1700C, a coating is formed around them and this coated layer reduces the water absorption property of aggregates, thus increasing their quality. This coating also reduces aggregate impact value, crushing value as well the abrasion value of aggregates. It was also found that Marshal Stability values are higher for plastic roads and there is less stripping of the road pavement than that of bituminous flexible pavement. It was also found that at 1600C, both plastics and bitumen are in the liquid state and capable of easy diffusion. Both polymer and bitumen are similar in chemical nature and they have better adhesion property. The marshal stability value of plastic pavement is fairly high having a Marshal quotient of around 500. Study suggested that, with the use of plastic waste coated aggregates, the quantity of bitumen needed for a good mix can be reduced to the extent of 0.5% of the total weight which accounts for 10% reduction in use of bitumen. The study also showed that in dry process bonding is more stronger than the wet process [2]. B G Sridevi et al.(2013) Studies showed that use of plastic coated aggregates has improved the stability. Strength of the plastic coated aggregates increased by 1.5 times for BC & SDBC. There is also reduction in voids in all types of mixes. Aggregates coated with waste plastic showed zero stripping after 72 hours of soaking where as ordinary bituminous mix showed 2% stripping. A massive quantity of plastic waste can be reused during the process of plastic road construction. This can reduce plastic waste load not only on landfills, but also on the marine resources. [3] Amit Gawande et al. (2012) studied extensively on PCA used pavement characteristics. It was stated that for flexible pavement, hot stone aggregates (1700C) is mixed with hot bitumen (1600C) and the mix is used for road laying. The coating of plastic decreases the porosity and helps to improve the quality of the aggregate and its performance in the flexible pavement. Further, in soundness test, the plastic coat aggregate showed no weight loss and hence the coating also helps in improving the soundness of the aggregate as well. Average plastic consumption in India has increased year after year. The following table given by Amit Gawande et al. (2012) showed

the increase in plastic consumption and waste burden on Indian landfills [4]. Table 1: Plastic Consumption Year

Consumption (Tonnes)

1996

61,000

2001

4,00,000

2006

7,00,000

2011

1,35,00,000

From the above discussions, we can conceive that use of waste plastic as coating materials helps in improving the physical characteristics of aggregates. Bitumen replacement by 10% with waste plastic helps in achieving financial efficiency and also helps in consumption of huge amount of plastic waste, which otherwise possess greater threat to our ecosystem. Construction Methodology: Plastic roads can be constructed adopting two processes, one being the Dry Process and other Wet Process of plastic road construction. Dry Process In dry process, initially the aggregates are heated up to a temperature of 1700C and shredded plastic pieces are spread over it. Due to the high temperature, plastic melts and forms a coat around the aggregate. This PCA is then mixed with hot bitumen at a temperature of (1600C). After proper mixing, the mixture is used for road laying operation. The aggregate is chosen on the basis of its strength, porosity and moisture absorption capacity as per IS coding. The bitumen is chosen on the basis of its binding property, penetration value and visco-elastic property. The aggregate, when coated with plastics improves its quality with respect to voids, moisture absorption and soundness. Besides this, the coating of plastic decreases the porosity and helps to improve the quality of the aggregate and its performance in the flexible pavement. It is to be noted here that stones with < 2% porosity are only allowed in the road construction, as per standards. Advantages of Dry Process: a) Improved characteristics of road aggregate. b) Almost about 8-10% bitumen replacement with waste plastic, hence attaining financial efficiency.

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Techsynthesis

c) No extra skill set is required. d) Increase in durability. e) Reduces the burden of plastic wastes on the environment. Wet Process Waste plastic is shredded into small pieces and these shredded plastic is replaced with bitumen up to about 6-8%. Plastic is mixed with the hot bitumen and it increases the melting point of the bitumen and makes the road retain its flexibility during winters resulting in its long life. By mixing plastic with bitumen the ability of the bitumen to withstand high temperature increases. The plastic waste is melted and mixed with bitumen in a particular ratio. The vigorous tests at the laboratory level proved that the bituminous

concrete mixes prepared using the treated bitumen binder fulfilled all the specified Marshall mix design criteria for surface course of road pavement. There was a substantial increase in Marshall Stability value of the mix is two to three times more than that of conventional bitumen aggregate mix. Another important observation was that the bituminous mixes prepared using the treated binder could withstand adverse soaking conditions under water for longer duration. [4] Advantages of Wet Process: a) This Process can be utilized for recycling of any type, size, shape of waste material (Plastics, Rubber etc.) b) Increases the durability of the pavements, thereby minimizing the maintenance cost.

Reference: [1] Trimbakwala, Ahmed. “Plastic Roads Use of Waste Plastic in Road Construction.” International Journal of Scientific and Research Publications 7.4 (2017).

[3] Sreedevi, B. G., and Salini PN. “Pavement Performance Studies on Roads Surfaced Using Bituminous Mix with Plastic Coated Aggregates.” International Journal of Engineering Research and Technology (IJERT) 2.9 (2013): 149-156.]

[2] Vasudevan, R. N. S. K., et al. “Utilization of waste polymers for flexible pavement and easy disposal of waste polymers.” International Journal of Pavement Research and Technology 3.1 (2010): 34-42.

[5] IRC:SP-98-2013

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[4] Gawande, Amit, et al. “An overview on waste plastic utilization in asphalting of roads.” Journal of Engineering Research and Studies 3.2 (2012): 01-05.

Engineering Conference, 2019

Techsynthesis Instrumentation and Control in Gas Compressors – A look at the present technologies and the future possibilities Raunaq Barkakati, Supdt. Engineer Instrumentation Rituballav Hazarika, Supdt. Engineer Instrumentation Nibedita Baruah, Supdt. Engineer Instrumentation ABSTRACT:

Pneumatic based Control Panels:

In this paper we will be discussing about the current technologies that we use for the control and safe shut down of Gas Compressor Packages in Oil India Limited and also, the possible technologies that can be incorporated in the coming years to ensure optimized operation of our Gas Compressors.

These panels are in service with Oil India Limited since the 1960s. There are approximately 90 numbers of gas compressors with pneumatic control panels. These panels use compressed air for actuation and control.

INTRODUCTION: In Oil India Limited, we use reciprocating type gas compressors in our Gas Compressor Stations (GCS). Natural Gas from Oil Collecting Stations (OCS) is received by the GCS at around 30 psig which is then compressed to around 250 psig by Low Pressure Booster Compressors. This gas is supplied to various internal and external customers. Furthermore to enhance crude oil production from gas lift wells, the gas at 250 psig is compressed to around 1500 psig by Gas Lifter Compressors. Gas compression in GCS also achieves the added benefit of reduced gas flaring.

Advantages:

1. Electrical power is not required for functioning like in the case of other systems.



2. Hazardous area certifications are not required.

Disadvantages:

1. Accuracy of measurement using these panels is much lesser compared to electronic panels.



2. Prone to wear and tear due to the presence of a lot of moving parts like 2 way and 3 way valves, relays etc.



3. Signal lines are prone to leakage and choking.

For safe and reliable operation of a gas compressor package, instrumentation plays a vital role in the monitoring of process parameters like speed, pressure, vibration, temperature etc and ensuring protection of both compressor and engine by using an array of sensors and final control elements.



4. Availability of spares is becoming an issue as pneumatic products are being phased out by OEMs.



5. Facility for historization of faults, alarms and events which is a very helpful tool in troubleshooting is not available.

EVOLUTION OF GAS COMPRESSOR CONTROL PANEL:

Relay Based Control Panels:

A control system is a system of physical components that continuously monitor the state of input devices and generates output based on user defined settings/ programs to control the process.

Relay based control Panels were introduced in Oil India Limited in 1983 and have been since phased out and replaced with PLC based control panels.

Oil India Limited has employed a variety of systems for the control of gas compressor packages over the years. These include pneumatic based panels, relay based panels, PLC based panels and panels with controllers specifically designed and programmed for gas compressor application.

PLC based control panels are in service with Oil India Limited since 1989 and are available with 10 numbers of gas compressors. In these systems, 2 way/3 way valves and indicating relays used in pneumatic systems have been replaced by logic solver and Human Machine Interface (HMI). Pneumatic field

PLC based Control Panels:

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Techsynthesis instruments have also been replaced by electronic field instruments which transmit the physical parameters in the form of 4-20ma/ 0-5Vdc signals. The logic of compressor control and shutdown which was executed via a complex network of mechanical valves and tubes in pneumatic panels is now implemented via a single logic controller. Advantages: 1. Amount of components in PLC based control panel is much lesser than in pneumatic panel which makes maintenance easier. 2. Higher resolution and accuracy of these panels and its associated field instrumentation. 3. Facility for historization of faults, alarms and events which is a very helpful tool for troubleshooting is available. 4. Self diagnostic features are available.

power failure a small UPS with battery backup is incorporated. 2. Hazardous area certification is needed.

Disadvantages: 1. Stable electrical power is required for its operation. 2. Hazardous area certification is needed. 3. Knowledge of programming languages is needed for troubleshooting. Specifically designed and programmed controllers for Gas Compressors: These controllers were introduced to Oil India Limited in 2007 and till date have been implemented in 23 numbers of gas compressors. These are PLC based systems which have been specifically built for optimising gas compressor package controls and operation. Advantages: Added to the advantages of PLC based control panels as mentioned above, these panels have the following additional advantages: 1. These panels are very user friendly and are field configurable. 2. They require little programming knowledge to troubleshoot problems.

To study this we have considered Hapjan GCS because this station has an almost equal mix of Pneumatic and Electronic Panels. We have compared the number of breakdowns per unit of Pneumatic and Electronic Gas Compressor Panels over a two year period from April 2017 to March 2019.s It has been observed that there is a marked decrease of maintenance notifications for Electronic Panels as opposed to Pneumatic Panels. It is also worth mentioning here that the average time taken for troubleshooting of faults is less in Electronic panels, due to better fault indications as well as lesser panel components.

Disadvantages: 1. Stable electrical power supply is needed. However, to protect the panel from power fluctuations and for safe shutdown during

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COMPARISON OF ELECTRONIC AND PNEUMATIC PANELS IN TERMS OF NUMBER OF BREAKDOWN • Total no. of notifications on Pneumatic panels: 18 • Total no. of notifications on Electronic panels: 13 • Total no. of Pneumatic Gas compressor panels: 7 • Total no. of Electronic Gas compressor panels: 6

ANALYSIS OF SPARES CONSUMPTION – ELECTRONIC VS PNEUMATIC PANELS

To analyse this we have compared the total expenditure on spares consumed since January 2019 till November 2019.

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Techsynthesis It is seen that we have spent 40% less on consumption of Electronic Panel spares than in Pneumatic Panel Spares. IN CONCLUSION-OUR WAY FORWARD The present scenario in Oil India Ltd. puts us at the cusp of change, where we now have a mix of Pneumatic and Electronic Control Panels. But the majority of our Gas Compressor Panels, more than 90 out of the nearly 123 panels, are still Pneumatic. Today, most OEMs of control systems are phasing out Pneumatic Systems and Components because the market demand for them is drying out and the spares for these systems are slowly becoming obsolete. Prices of the remaining available Pneumatic spares are increasing at a high rate. Moreover, the Oil & Gas Industry is now laying an emphasis on its Digital Transformation and towards the implementation of Digital Oilfield Technologies. The white paper titled “Digital Transformation Initiative - Oil and Gas Industry” [1] published in 2017 by the World Economic Forum in collaboration with Accenture states that “Digital transformation in the Oil and Gas industry could unlock approximately $1.6 trillion of value for the industry, its customers and wider society.” The report stresses the importance of digitization for the Oil & Gas Industry as the need of the hour. It also emphasises the need for its denizens to fully embrace this digital drive through top-driven change management and by promoting innovative, digital thinking. The next step then, for us, would be to start a timebased plan for conversion of our existing Pneumatic Gas Compressor Control panels to Electronic based Panels. This planning should take into account the latest technological advances made for Gas Compressor controls in order to choose the system best suited for our operational needs. It would also

require us to ensure that all auxiliary requirements such as stable power availability, electronic field instruments, etc. are put in place. Stations and units have to be identified for conversion in a phasewise manner so that our operations and economic goals are not hampered. In addition to the benefits mentioned earlier that are derived from Electronic Panels, this conversion would push us one step closer towards digitization and enable us to have all relevant data about the compressor packages in a digital format which can then be recorded and analysed. With the upgradation of Gas Compressor control systems from pneumatic to electronic systems, the next step would be to integrate all the PLC controlled units of a Gas Compressor Station with a Distributed Control System (DCS). DCS can be implemented for the complete monitoring and control of a Gas Compressor Station and integrate with the control systems of Gas Compressors, Air Compressors, Glycol Dehydration Units, etc. as well as collect parameter data from various instruments in process lines and vessels and provide all these information to a Centralised Control Room. DCS can also control various plant and unit level parameters such as pressure, temperature, flow, etc. to ensure that the Gas Compressor Station operation is optimized. A separate and independent Emergency Shutdown (ESD) system could also be implemented for executing safe shutdowns of the individual units and the entire station. It is our hope that this digital transformation of Pneumatic Panels to Electronic Panels, along with DCS for each GCS, if executed, will be instrumental in providing the data required by Digital Oilfield Technologies such as OIL’s Project Drive to run advanced analytics for optimizing the operations and maintenance of Gas Compressors.

References:

[1] White Paper –“Digital Transformation Initiative Oil and Gas Industry” published in 2017 by the World Economic Forum in collaboration with Accenture under the “The Digital Transformation Initiative” project.



[2] ERP-SAP PM and MM module



[3] http://www.altronicinc.com/pdf/altcontrols/exacta-21-5-10

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Techsynthesis Augmentation of electrical controls of drilling rigs in Oil India Limited

- Journey till Now Dwip Jyoti Goswami, Sr. Engineer Electrical

Pragyan Thakuria, Sr. Engineer Electrical

Drilling of hydrocarbons began in the world with the first well in 1859 at California. In early years of 20th century, 1901 to be exact, the first drilling well was developed in Asia at Digboi. After years of manual drilling, mechanical drilling rigs were introduced in Oil India Limited (erstwhile BOC). The mechanical drilling rigs employed engines to run the drilling equipment enabling the company to reach greater heights below the ground then earlier. With the advancement of technology, the use of electrical motors in drilling became viable. Thus improving the efficiency of the drilling rigs, DC motors started driving drilling rigs in search of hydrocarbons. The drilling DC motors were powered by individually coupled DC generators whose speed was governed by WardLeonard method. The auxiliary powers were delivered by additional AC generator set placed at the rig. In the late twentieth century, to do away with the demerits of one generator one drive strategy, lower accuracy in speed control and requirement of additional ac generator set for the auxiliary power, AC-SCR technology was adapted in drilling rigs. In this

system ac power was generated using IC engines at 600 Volts and then fed to the DC drilling motors which in turn drives the drilling equipment. The conversion from AC to DC was done by SCRs. The generator output control and motor speed control was achieved to a great accuracy using a strategy known popularly as Ross Hill or Hill-Graham control. The only reason that high efficiency, more robust and low maintenance AC motors couldn’t be used at this stage was absence of proper speed control strategy for the AC motors. But early twenty-first century brought with it the VFD technology, a technology that was fast adapted across variety of industries to overcome the demerits of using dc motors. VFD proved its worth across industries and became a trustworthy alternative of the AC-SCR technology. This new member of cutting-edge technology successfully drew the attention of the drilling rig designers. And with this, VFD technology was being introduced to the drilling business. With VFD, the drives could now be driven in a more efficient and convenient manner.

Fig: Transition of technology in drilling rigs over the years.

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Techsynthesis Riding on a parallel track, some significant technological upgrades were introduced in the machine communication system in the drilling rigs. The days of analog voltage communication, in which signal dropped when transmitted over long distance, were over with the introduction of PLC. But the designers choose not to settle here. They now have introduced fiber optics communication now. We shall now sail through the latest technology used for driving the exploration of hydrocarbons in Oil India Limited.

VFD Drive Basics A variable-frequency drive (VFD) is a type of adjustable-speed drive used in electro-mechanical drive systems to control AC motor speed and torque by varying motor input frequency and voltage. This technology enables the industries to use the more efficient, reliable and maintenance free AC motors for various operations with accurate speed control. A VFD consists basically of three blocks: Rectifier, DClink and Inverter. The Rectifier converts sinusoidalACpower to a constant DC power.The DC link consists of a capacitor which smooths out the converter’s DC output ripple and provides a stiff input to the inverter. This filtered DCvoltage is converted to quasi-sinusoidal AC voltage output using the inverter’s active switching elements. Rectifier The rectifier/converter consists of 6 pulse semiconverter bridges that convert three-phase AC to a fixed DC. The arrangement of three-phase Bridge is as follows: The relationship between the AC input voltage and output voltage of the 6 pulse converter is given by the equation VDC = 1.35 x VAC. So for a system of 600 V AC the average DC Output Voltage is 810 V.

The main intension of using the semi-converter is to charge the dc-link capacitor within its charging time (not instantaneously) by gradually changing the gate angle of the SCRs of the semi-converter. Once the dclink capacitors are fully charged, the semi-converter unit will act as an un-controlled rectifier unit. In order to attenuate the harmonics that are injected into the AC Bus by the Converter Bridge, Input Reactors are used. They also reduce the current ripples on the DC Bus. DC Link A common DC link is present in which two or more inverters are connected to it via disconnect switches and share more than one converter bridges. The use of a common DC link increases the system redundancy. The DC link also consists of capacitor which smooths out the converter’s DC output ripple and provides a stiff input to the inverter. Inverter

The inverter is the output section of Variable Frequency Drive. It consist of IGBT semiconductor switches and electrolytic capacitors mounted on heatsinks. These IGBTs are switched ON and OFF in a specific sequence to produce a three phase output voltage of variable amplitude and frequency. The switching technique used is Pulse Width Modulation (PWM).The output current is almost sinusoidal (stepped sinusoidal). The output voltage is varied by varying the gain of the inverter and output frequency is adjusted by changing the number of pulses per half cycle or by varying the period for each time cycle. The inerter uses bipolar semiconductor device- IGBT to allow the flow of power back into the dc- link bus once the drive is in braking mode. But since the converters do not use the bi-polar device, the power cannot be fed back into the ac mains.

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Techsynthesis Dynamic Braking/ Electrical Braking

Drive Control For controlling the drives both converter and inverter units are equipped with RDCU Board (R- Series Drive Controller Unit). Communication between RDCU and inverter/ converter is made through a fiber optic link. Fiber optic connections are made from RDCU to AINT (A- Series Interface Board) and CINT (CSeries Interface Board) for Inverter and Converter respectively. The drive is controlled, protected and monitored by a Digital Control Module (DCM). The DCM is responsible for all motor control operations and bridge control for inverters and converters. The control module is loaded with firmware file. This file contains all the necessary motor control programs as well as DCM’s operating system. The DCM receives feedback from AINT/ CINT board via fiber optic link. All the primary signals of inverter (DC link voltage, IGBT current, heat-sink temperatures)

The AC drives installed for Drawworks, Top Drive are equipped with dynamic braking, which consist of Braking Chopper and Resistor Bank. Dynamic Braking or electrical braking occurs when the inverter’s output (motor input) frequency is less than the corresponding rotor speed. During this period the AC motors act as Induction Generator and the AC current flows back to the drive. This Ac power is rectified by freewheeling diodes of the IGBTs and flows into the DC link as direct current. This regenerated energy may be consumed by other inverters connected to the common dc-link bus. If not, the regenerated energy will cause the DC link voltage to rise. If DC voltage exceeds beyond a pre-

and converter (AC Supply Voltage, heat-sink temperatures, DC link voltage, Input Current, Output Current) are processed by AINT/ CINT board and transmitted to DCM. Based on the input speed commands, load torque, motor speed feedback, the DCM adjust the switching patterns of the IGBTs so that the commanded motor speed and torque is realized.

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Techsynthesis determined set-point, the excess energy is dissipated across the Resistor Bank by the Braking Chopper. An electronic card NBRC inside the NBRA checks if the dc-link voltage if above the threshold level which in turn dissipates the additional power through resistor bank.

Top Drive System of VFD Drilling Rigs The VFD rigs of OIL are equipped with the cutting edge drilling equipment. Top Drive System (TDS) is one such equipment. TDS is used by the upstream companies all over the world for better efficiency of drilling. The TDS unit we use is from National Oilwell Varco (NOV). The NOV TDS has some inherent benefits which makes drilling easier and efficient. The TDS allows drilling with up to three (03) drill pipes connected together. Also it allows back reaming, increasing the probability of releasing a struck. Also, a twist function (which allows alternate clockwise and counter-clockwise movement of the drill bit) reduces the probability of struck. Amongst the large product range of TDS available with NOV, we are using the most popular TDS-11SA TDS. It employs two 400 HP VFD motors (a total of 800 HP) thus producing a drilling torque of 37500 ft. lb. and make up and break up torque of 55000 ft. lb. With a hoisting capacity of 500 Tons the TDS can be continuously rotated at 228 rpm. Equipped with a counterbalance mechanism, The TDS saves thread damage of the drill pipes during make up and break out without any manual interference. The TDS system is equipped with two disc break

units, one for each motor. Also an encoder on the right motor feeds the VFD drive with the exact motor speed. This speed feedback is addition to the speed of the motor calculated internally by the drive. The TDS system is powered by NOV make rectifier unit and ABB make inverter units. For controlling the operation of the TDS, AMPHION control is being used. AMPHION system uses Single Board Computers (SBC) as the central processing unit aided by optical fibers and PROFIBUS cable for communication. Whenever conversion from optical signal to PROFIBUS signal is warranted, Optical Link Module (OLM) are used. The AMPHION system offers the luxury of drilling on touch screens or stateless hard switches. Any one or both system of drilling can be used without any switch over whichever pleases the driller/ assistant driller. Our TDS system is equipped with WAGO make modules which acts as the input and output modules. And input from the driller to the TDS is fed into the WAGO input module which is then carried to the SBC. The SBC analyses the command from the driller and gives the necessary output command to the various auxiliaries attached with the TDS unit. The TDS is also equipped with an add-on feature of monkey board anti-collision system, which has not being used by us. Recently the AMPHION upgrade AMPHION 2.0 offers additional benefits of data analysis and storing by the system. This will further reduce the human dependence for drilling thereby improving the system efficiency.

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Techsynthesis GREENER & LEANER Constraints and outlook in sustainable transportation Kunal Anand, Sr. Engineer Logistics ABSTRACT The paper discusses the various recent initiatives of the government of India to reduce the import dependence on crude oil and development of better indigenous fuels. Apart from the schemes, the paper also draws attention to the various enablers and constraints that lie ahead of these initiatives. INTRODUCTION In recent times, the media is flooded with reports on electric vehicles and how electric/alternate mobility solutions will change the country’s energy and transportation landscape in times to come. The major reason for such reports is the visible thrust of the government of India to shift to sustainable fuels/energy sources from the conventional ones. The main driving forces for these policies are as follows: ENVIRONMENTAL: • The total number of registered motor vehicles in India was 21 crores as on 31.03. 2015. With an annual production of around 2.5 crore automobiles, the present strength of automobiles running on Indian roads stands at nearly 28 Crores. • According to World Health Organization (WHO), Delhi tops the list of most polluted cities. Among the world’s 20 most polluted cities in the world, 13 are in India. • India is in the group of countries that has the highest particulate matter (PM) levels. Its cities have the highest levels of PM10 and PM2.5 (particles with diameter of 10 microns and 2.5 microns). • At the level of more than 150 micrograms, Delhi has the highest level of airborne particulate matter PM2.5, considered most harmful. These figures are six times more than the WHO “safe” limit of 25 micrograms. Uncontrolled vehicular traffic being the primary reason. FINANCIAL : • India was the third largest crude oil importer in

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the world in 2018. The country spent an estimated ₹8.81 lakh crore (US$130 billion) to import 228.6 million tonnes of crude oil in 2018-19 PROPOSED SCHEMES OF GOI • The government has announced an outlay of ₹10,000 crore for Phase 2 of the Faster Adoption and Manufacturing of Hybrid and Electric Vehicles, or FAME 2 Scheme, to boost electric mobility and increase the number of electric vehicles in commercial fleets. • Ethanol Blended Petrol (EBP) programme was launched in January, 2003. The programme sought to promote the use of alternative and environment friendly fuels and to reduce import dependency for energy requirements. • Adoption of new bio-fuels policy for mainstreaming of bio-fuels in energy and transportation sectors. • The Supreme Court of India has ruled that no Bharat Stage IV vehicle shall be sold across the country with effect from April 1, 2020. Instead, the Bharat Stage VI (or BS-VI) emission norm would come into force from April 1, 2020 across the country. CASE STUDIES AND ANALYSIS ELECTRIC MOBILITY Case study: Nordic countries • The Nordic region – Denmark, Finland, Iceland, Norway and Sweden have been the earliest adopter of Electric vehicles. Leading the pack is Norway where 1 out of 16 cars on road is electric.

• Despite the dynamic nature of the electric car market in the Nordic countries, electric cars only account for less than 1% of total electricity demand in the region.



• The number of electric vehicle supply equipment (EVSE) outlets, i.e. electricity charging points for vehicles, in the Nordic region was

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Techsynthesis close to 264 000 in 2017, of which over 16 000 are publicly accessible. • By 2030, it is projected that 4 million electric cars will be on the road in the region, implying more than a 15-fold growth of the electric car stock from 2017 volumes. Norway and Sweden are leading this growth accounting for 80% of the region’s total EV stock in 2030 • Consequently, it is estimated that the use of 4 million electric cars in 2030 in the Nordic countries would emit 0.2 million tonnes of carbon-dioxide equivalent (MtCO2-eq). This value is 40 times less than the emissions from the same number of ICE cars, which would emit 8.4 MtCO2-eq in 2030. • Reducing the purchase price proved to be the main driver of the high electric car adoption rate, followed by waivers or partial exemptions on use and circulation taxes or charges and other local policy incentives, such as free parking or access to bus lanes. • The vehicle technology option with the lowest purchase price – after the application of incentives – tends to achieve the highest sales share in each of the Nordic countries. Constraints and outlook in the Indian context Environmental: Unlike Nordic countries, the Indian power basket is highly dependent on fossil fuels (64% coal). Given this power basket, 1 kWH of produced power leads to nearly 300g-equivalent of CO2 production. Running an electric vehicle on this electricity produces nearly 370g-equivalent of CO2/km(including transmission loss, efficiency loss etc.). In contrast, running a vehicle on petrol nearly 295 g-eq CO2 per km. Comparing these values, it is quite evident that the current power basket of India does not present Electric mobility as a environment friendly option. Power Infrastructure:

• The current generated electricity in India(~360 GW) falls short of the demand by 0.7%. In comparison, Norway exports around 10% of its produced electricity.



• Indian manufacturers produce nearly 30Lakh



passenger cars per year. Aiming for 10% electric car sales till 2022 will result in nearly 9 Lakh cars. These cars will require nearly 2 TWh of electricity which comprises nearly 0.16% of the national production. With a Net CAGR 0f 2.24% in electricity generation, the target seems achievable. • However, the charging units for these cars come in different variants. The lowest power consuming “slow charger” requires an input power of nearly 3.7Kw and takes nearly 6-12hrs in charging time. Using such a high power device might put a limit on the other devices given the current domestic supply infrastructure of India.

Technical infrastructure: • Electric vehicles are powered by Lithium-ion batteries. These battery backs are at the heart of the vehicle and may cost upto 50% of the vehicle. While Australia and Chile are bigger producers—Chinese firms currently control almost half the global lithium production and 73% of the global cell manufacturing capacity • India imports lithium-ion cells from China, Taiwan and South Korea. India paid nearly $1.23 billion for lithium-ion batteries of capacity nearly 1GWh in 2018-19. The introduction 10% electric vehicles in annual will require an additional requirement of nearly 7-12GWh of Li-ion battery power per year. • With bulk of battery manufacturing facilities

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Techsynthesis concentrated in a few countries and surging prices of the raw materials due to supply demand mismatch the import might cost anywhere between $ 8.6-18 billion per year. Financial infrastructure: • An average Electric car runs around 8-10Km/ kWh costing less than a rupee/km. However, the upfront cost of electric cars has been the hindrance to their widespread acceptance. • At present, the major EV’s available in the Indian markets are from manufacturers like TATA, Mahindra and Hyundai costing between 10-25 Lakhs. BIO-ETHANOL Case study: Brazil 1973

- Oil crisis hits Brazil

1975

-Increase ethanol production as a substitute for gasoline - Invested in increasing agricultural production - Modernizing and expanding distilleries - Establish new production plants - Introduce subsidies to lower prices and reduce taxes for ethanol producers

1978

- One part of ethanol was added to four parts of gasoline. - Additional processing stage to remove water from the fuel

1979

- Production streamlined to focus on hydrous ethanol - Ethanol which contains 5% water that could be used in cars fuelled entirely by ethanol

1989

-90% of all new vehicles sold in the domestic market were ethanol-fuelled. -Over 15 years, production of ethanol escalated from 0.6 billion litres in 1975 to 11 billion litres in 1990

• Most automobiles in Brazil run either on hydrous alcohol (E100) or on gasohol (E25 blend), as the mixture of 25% anhydrous ethanol with gasoline is mandatory in the entire country.

• Ethanol is produced from sugarcane. The by-products of which are vinasse (a liquid byproduct) and bagasse. Vinasse is used as a fertilizer while bagasse is used for generation of electricity.



• Ethanol combustion produces lesser CO2 emissions than petrol. Ethanol has a octane number >100 and hence addition of ethanol to petrol improves the combustion.



• Flexi fuel engines are engines which can work on wide range of petrol-ethanol blend.

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Constraints and outlook in the Indian context Ethanol Blending Program (EBP) • During 2001, pilot projects on Ethanol Blended Petrol started at 3 locations i.e. at Miraj, Manmad (Maharashtra) and Aonla/Bareilly in Uttar Pradesh. The Government of India decided to launch Ethanol Blended Petrol (EBP) Programme in January, 2003 for supply of 5% ethanol blended Petrol. • The Ministry of Petroleum & Natural Gas (MoP&NG) vide its notification dated 20th September, 2006 directed the Oil Marketing Companies (OMCs) to sell 5% Ethanol Blended Petrol 20 states and 4UTs. • GoI is aiming to achieve 20% blending in petrol throughout the country by 2030. The main constraint to this is the unavailability of ample surface water and sown area. To achieve a petrol ethanol blend of 20% at least 8% more land area has to be sown with sugarcane. • Numaligarh Refinery Ltd. Has signed a deal with Finnish firm Chempolis for setting up of refinery for production of bio-ethanol from bamboo. • The bio-refinery will use 300,000 tons of bamboo annually from the vast natural and cultivated bamboo reserves of Northeast India. The plant will produce annually 60 million liters of bio-ethanol BIO-DIESEL Case study: The Jatropha fiasco • In December 2009, the Union government launched the National Biodiesel Mission (NBM) identifying Jatropha as the most suitable treeborne oilseed for biodiesel production to help achieve a proposed biodiesel blend of 20 per cent with conventional diesel by 2017 • However, due to an acute shortage of Jatropha seeds, the government’s ambitious plan did not materialize. • Availability of Jatropha seeds remains a major problem in increasing the production of biodiesel in India. Also, Jatropha has a high gestation period(3-5 years) and hence the farmers find it a difficult crop to grow. • The jatropha plant didn’t have any other use

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Techsynthesis apart from biodiesel production. The delayed returns on the crop and lack of versatility led to a complete disaster in the supply of biodiesel. Initiatives in the Indian context Repurpose Used Cooking Oil (RUCO) • Traditionally Biodiesel has been produced from Waste vegetable oil, animal fats etc. in developed countries. • Recently in August 2019 GoI started the repurpose used cooking oil (RUCO) scheme which aims to collect used cooking oil and convert it into biodiesel • FSSAI has laid down regulations to monitor the usage of used cooking oil. These new regulations limit Total Polar Compounds (TPC) to a maximum of 25 percent. • RUCO is a fully tech-enabled mechanism, which runs with minimum human intervention. It has two apps - one for a food business owner or ‘discharger’ to request for a pickup of the used oil, and another for drivers who get pickup requests in the vicinity. • Presently, as many as 64 companies, 200 aggregators, 350 hubs and some 26 plants initiatives in 101 locations across the length and breadth of the nation are working together to enable the collection and conversion of Used cooking oil. COMPRESSED BIOGAS Case study: Sweden • Biogas is produced naturally through anaerobic decomposition from waste or biomass sources. The biogas produced contains approximately 55% to 60% methane, 40% to 45% carbon dioxide and trace amounts of hydrogen sulphide. • Biogas is purified to remove carbon dioxide and hydrogen sulphide gases to prepare Compressed Bio Gas (CBG) or Bio-methane • CBG has calorific value and other properties similar to CNG and hence can be utilized as either a blend or replacement of CNG • Sweden is world leading both in terms of automotive use of Bio-methane and its non-grid based transportation. • Unlike most EU countries Sweden doesn’t have a nationwide Gas grid and hence opted for Local gas grid and road transport system for



transportation of Bio-methane. • BiMe-Trucks, a project financed by the Swedish Energy Agency, played a crucial role in Sweden’s bio methane project by developing LNG/ LBG powered road haulage trucks equipped with energy-efficient methane diesel engines

Initiatives in the Indian context • GoI plans to set up 5000 CBG plants in the next four years with an investment of nearly 1.75 Lakh Crores. • These plants will supply to the OMCs which will use them as a blend/substitute for the CNG customers. • Case in point:- Mahindra world city, Chennai • The Bio-CNG plant at the Mahindra World City in the outskirts of Chennai city converts eight tons of food and kitchen waste generated daily in the city into 400 kg/day of CNG grade Biogas. • The Gas is used to drive shuttle buses and agricultural tractors creating a carbon neutral ecosystem. CONCLUSION Although the government is providing a huge push towards the introduction and adoption of electric vehicles as well as bio-fuels, there seem to be many constraints in the path. Even though electric mobility seems a bit farfetched in the Indian context, the second generation bio-fuels may contribute significantly to the Indian power basket in the coming times. Also, the shifting focus towards renewable energy sources for power generation may give a much needed push to the electric mobility landscape. Innovative bio-fuel policies and increasing awareness among the people may also prove instrumental in adoption of greener and cleaner fuels.

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Techsynthesis DETERIORATION OF CONCRETE IN NAMRUP BVFCL PLANT; A CASE STUDY Himangshu Bhuyan, Sr. Engineer Civil Abstract — The problem of deterioration of Reinforced concrete (RC) structures poses a serious concern to the strength and stability of systems. In the present paper, causes of deterioration of an RC wall with increasing age in an urea manufacturing P.S.U (Public Sector Unit) named Brahmaputra Valley Fertilizer Cooperation Limited (BVFCL) is studied. The work illustrated that due to the crystallization of urea trapped inside the RC walls, a continuous stress is developed on the walls and is responsible for the spalling of concrete from the RC walls. This long time deterioration of concrete might have an adverse effect in the service life of the structure. Keywords — Crystallization Pressure, Salt Crystallization, Urea, Urea dust, Urea prills;

I. INTRODUCTION

Table 1. Chemical and physical properties of urea

1.1 Significance: Deterioration of RC structures leads to loosened concrete with reduced compressive strength, reduced sectional area, redistribution of the internal force and decrease of the reliability. Spalling of concrete exposes the reinforcement to environmental attack and results in corrosion of rebar. The corrosion of rebar decreases the carrying capacity and ductility of RC elements. Furthermore deterioration of concrete in an industrial building may hinder the normal production and also put the safety of its workers at stake. BVFCL is located on the bank of the river Dilli in the south-western border of Dibrugarh District in Assam, India. This is the first factory of its kind in India to use associated natural gas as basic raw material for producing nitrogenous fertilizer [1]. BVFCL Namrup has the following finished product: Prilled Urea (Brand Name: Mukta Urea), Neem Coated Urea, Biofertilizer and Vermi-compost [1]. Here prilling refers to the pellet formation of urea melt. In BVFCL UreaIII plant has a production capacity of 900MT/day and it works through a group of sections --Synthesis section, Decomposition section, Concentration and prilling section and Recovery and absorption section [2]. The expected discharge of urea dust from the prilling tower of the plant is 200Mg/NM3 of air (max.). Table 1 shows the chemical and physical properties of the urea from BVFCL.

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The industry is facing a serious problem in their prilling towers. The RC walls (Reinforced Concrete walls) of the Urea-III prilling tower are highly exposed to urea. During a visit the authors found spalling of concrete from the walls and formation of crystalline Silk like compound (SLC) as shown in the Fig 1-2. Due to this the reinforcement of the walls are being exposed to the environment and as a result corrosin is taking place. The corroded rebars with reduced tensile strength and ductile capapcity, endangers the safety and service life of the structure.

Figure 1Spalling of RC walls

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Figure 3. EDX result.

Figure 2. Formation of SLC on walls II. LITERATURE REVIEW The work on effect of urea on fresh concrete is very common [3; 4]. But to the best of author’s knowledge, the influence of urea on hardened concrete is not known till date. So in this case the results of the paper will proved to be an important tool for understanding how urea can cause spalling and it will also find a path for research to overcome such affect in order to save the existing structures.

Figure 4. EDX spectrum

III. EXPERIMENTAL STUDY 3.1 Analysis of the SLC During the study the authors came across some silk like compound (SLC). The recognition of this unknown compound is very important. Study shows that this compound has some similar behaviour as urea. It is water soluble and makes our hand slippery when in contact with moisture. The chemical composition of urea (CH4N2O) is shown in Table 2.

Figure 5. Electron image Again when urea solution is allowed to evaporate it forms this SLC shaped structure on the surface as shown in the Fig6.

Table 2 Chemical composition of Urea

Again FEG-SEM EDX [5] of this SLC shows the following result (Figs 3-5). This result shows that the SLC has approximately similar composition as that of urea.

Figure 6. Crystal formation due to evaporation of urea solution

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Techsynthesis In order to attain a confirmed result we make two solution one containing urea and another containing SLC. Both in acidic medium forms a lemon yellow colour when few drops of paradimethyl-amino-benzaldehide (PDAB) is added. This is demonstrated in the following Figs 7-8.

then left undisturbed in a closed chamber for one month, which results in SLC formation (Figs 9-10). This is the scenario inside the prilling tower.

Figure 9. Before immersing to urea solution

Figure 7. SLC solution turns lemon yellow

Figure 8. Urea solution turns lemon yellow. According to M XiaoJie, lemon yellow material will form when para-dimethyl-amino-benzaldehide (PDAB) will react with urea under acidic condition [6]. Hence it confirms that SLC is nothing but urea. 3.2 Spalling of Concrete To determine the cause of spalling is very important as it is reducing the strength of the RC walls of the prilling tower. A sample of concrete from the prilling tower is immersed in 40% conc. Urea solution. It is

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Figure 10. After one month During the prilling process the urea dust is also

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Techsynthesis produced. This dust get settled on the walls of the tower. As urea is hydroscopic in nature [7]. It can absorb moisture resulting in the formation of concentrated urea solution. The tower was manufactured 30 years back (as per BVFCL database), so the walls have developed large number of micro as well as macro pores. The distribution of pore size are the major factors controlling the uptake and transport of liquid in a stone [8]. Same is the case here. The urea solution get absorbed by the walls of the tower and enters these pores. When the evaporation of the absorbed urea solution takes place, it results in the formation of urea crystals in the pores (sub-efflorescence) of the walls and also on its surface (efflorescence). Such formation of crystals is taking place for many years till date. C.W Correns derived an equation [9; 10] for quantifying the crystal pressure as P=(RT/Vs)ln(c/cs) where P (atm) is pressure, T (K) is temperature, R (cm3atm K-1 g-mol-1) is gas constant, c/cs is super saturation ratio and Vs (cm3mol) is molar volume of crystal structure. In our case as a result of the sub-efflorescence the walls are undergoing a pressure from the crystal formation which is a similar condition of salt crystallization in concrete according to Correns

equation [11; 12]. This formation of urea crystal in the pores of the wall of the prilling tower is continuously taking place for a long time, so the stress from them is also continuous. As a result of this stress, cracks occurs on the walls. Hence this phenomenon of urea crystal formation explains the deterioration of the walls of the prilling tower. Further research (SEM and XRD of the wall) is required for clear visualization of the rate of crystals formation. CONCLUSION A case study for identifying the cause of RC wall deterioration of BVFCL‘s Urea III prilling tower was conducted. The study revealed that spalling of concrete in BVFCL‘s Urea III prilling tower was primarily due to the formation of urea crystals inside the pores of the walls. The Silk like compound formed on the walls are only urea crystals due to efflorescence. This crystal formation inside the walls exert stress on concrete which resulted in cracks. The extent of deterioration is to be determined through further research so that the service life of the tower can be predicted. This has to be done soon as the deterioration is still in progress. Moreover further research may be done how to prevent the formation of crystals and what precautions should be taken for such type of constructions.

REFERENCES: [1] About BVFCL http://www.bvfcl.com/ [2] Process description UREA III (Production Dept. BVFCL) [3] RamazanDemirbog˘, FatmaKaragöl, RızaPolat, Mehmet AkifKaygusuz “The effects of urea on strength gaining of fresh concrete under the cold weather conditions”, Construction and Building Materials 64 (2014) 114–120 [4] ShaabanMwaiuwinga, ToshikiAyano and Kenji Sakata, “INFLUENCE OF UREA IN CONCRETE”,Cement and Concrete Research, Vol. 27, No. 5, pp. 733-74X1997 [5] SAIF IIT Bombay, refer no. SAIF/l/2015.02.10/FEC- SEM-166 [6] MaioXiaoJie; Jiang EnChen; Wang Jia; Du YanHong, “Using Spectrophometry with para-dimethyl-amino- benzaldehyde as chromogenic agent to determine macro and micro urea in aqueous solution ”, DongbeiNongyeDaxueXuebao 2011 Vol. 42 No.8 pp. 87-91 [7] W.E.Clayton, “Humidity factors affecting storage and handling of fertilizers”, IFDC 1927 [8] C Rodriguez Navarro and E Doehne, ‘Salt weathering: influence of evaporation rate, supersaturation and crystallization pattern’, Earth Surface Processes and Landforms, 1999 Vol 24, No 3 [9] Correns, C.W. 1949. ‘Growth and dissolution of crystals under linear pressure’, Discussions of the Faraday Society, 5: 267–71. [10] Flatt, R.J., Steiger, M., Scherer, G.W. 2007. ‘A commented translation of the paper by C.W. Correns and W. Steinborn on crystallization pressure’. Environmental Geology, 52: 187–203. [11] Heather

Viles, “Salt crystallization in masonry”, Buildingconservation.com

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Techsynthesis A Study on Possibility of Use of River Silt as Replacement of Natural Sand in Concrete Tulika Das, Sr. Engineer Civil

Abstract: Sand is the most widely used fine aggregate in the process of manufacturing concrete. The river beds are the main sources for the natural sand. The natural sand is transported from its available places to the construction sites. Transporting river sand to the construction sites increases its sale price significantly. Due to short supply of natural sand and the increased activity in the construction sector, there is an acute need for a product that matches the properties of natural sand in concrete. Sand can be replaced by slit as a fine aggregate in construction sites. The root cause of Brahmaputra’s flood is a large amount of silt carried by the river from neighbouring states which is about 1.87 billion tons per year. Due to this the river bed of Brahmaputra is rising gradually and reduces its water carrying capacity. That is why; a study was performed regarding possibility of use of silt as replacement to natural sand in concrete. From the analysis it was observed that river silt can be used as replacement to natural sand and also reduces the cost of construction. Keywords: Silt, Sand, Compressive Strength, Specific Gravity, Mix Proportioning • INTRODUCTION Necessity of replacement of sand: Sand is a major component of concrete and without it; concrete will not function as intended. The properties of a specific concrete mix will be determined by the proportion and type of sand used to formulate the concrete. The major components of concrete are cement (typically Portland cement), sand, aggregate and water. The larger stones and gravel are called coarse aggregate and the sand is referred to as fine aggregate. Sand is usually a larger component of the mix than cement. The demand of natural sand is very high in developing countries to satisfy the rapid infrastructure growth. The developing country hence facing shortage of good quality natural sand and particularly in India, natural sand deposits are being used up and causing

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serious threat to environment as well as the society. Rapid extraction of sand from the river bed has given rise to serious environmental problems losing water retaining of soil strata, deepening of river beds and bank slides, loss of vegetation on the bank of rivers. Besides this it also affect the aquatic life as well as disturbs agriculture due to lowering of water table in the well. Moreover to meet the excessive demand of sand, hill cutting is carried out at alarming rate which is also leading to a serious consequence to the environment. Due to high rise of construction industry and depletion of natural resources, sand is becoming very costly. It has become essential to find cheaper and easily available alternative material to natural sand. One such alternative material is silt. Silt is granular material of size less than 0.075mm but greater that 0.002mm, whose mineral origin is quartz and feldspar. Silt may occur as soil (often mixed with sand or clay) or as sediment mixed in suspension with water and soil in a body of water such as a river. • EXPERIMENTAL Data Gradation analysis: Particle size determinations on large samples of aggregate are necessary to ensure that aggregates perform as intended for their specified use. A sieve analysis or gradation test determines the distribution of aggregate particles by size within a given sample. It is done with reference to IS 383:1970. •

Gradation Results of Silt

IS sieve size (mm)

4.75

2.36

1.18

0.60

0.30

0.15

Percentage Passing

100

99.99

99.78

99.32

82.99

13.11

Specified Limits for Zone-IV

95100

95-100

90-100

80-100

15-50

0-15

Remarks: Silt does not conform to Zone-IV as per IS 383:1970

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• CONCRETE MIX PROPORTIONING

Gradation result of Sand

IS sieve size (mm)

4.75

2.36

1.18

0.60

0.30

0.15

Percentage Passing

100

100

98.08

87.50

24.56

13.11

Specified Limits for Zone-IV

95100

95-100

90-100

80-100

15-50

0-15

Remarks: Sand conforms to Zone-IV as per IS 383:1970

It is the process of selecting suitable ingredients of concrete and determining their relative amounts with the objective of producing a concrete of required strength, durability and workability as economically as possible. The actual cost of concrete is related to the cost of material required for producing a minimum mean strength called characteristic strength. Requirements of concrete mix design:

• Gradation result of Course Aggregate (20mm) IS sieve size (mm)

40

20

10

4.75

0.30

0.15

Percentage Passing

100

96.17

4.5

0.1

24.56

13.11

Specified Limits for Zone-IV

100

85-100

0-20

0-5

15-50

0-15

The requirements which form the basis of selection and proportioning of mix ingredients are:

• The minimum compressive strength required from structural consideration.



• The adequate workability necessary for full compaction with the compacting equipment available.



• Maximum water cement ratio and /or maximum cement content to give adequate durability for the particular site conditions.



• Maximum cement content to avoid shrinkage due to temperature cycle.

Remarks: Course Aggregate (20mm) conforms to IS 383:1970 specification

D. Tests Conducted Tests Material

Moisture Content

Water Absorption

Specific Gravity

Silt

3.8%

1.0%

2.56

Sand

1.2%

0.8%

2.62

Coarse Aggregate

0.11%

0.3%

2.64

Concrete mix design is performed as per IS 10262:2009

• For M 20 Grade of concrete using Silt as FA

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Techsynthesis •

For M 25 Grade of concrete using Silt as FA

•

For M 30 Grade of concrete using Silt as FA

•

For M 20 Grade of concrete using Sand as FA

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For M 25 Grade of concrete using Sand as FA

•

For M 30 Grade of concrete using Sand as FA



• RESULTS • Compressive Strength of M 20 Concrete using Silt as FA

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Techsynthesis 7 days Strength W/C Ratio

0.55

0.50

0.45

Sample I

II

III

I

II

III

I

II

III

415

460

525

505

515

550

525

Load Taken (kN) 230

510

Strength (MPa) 10.22 18.44 20.44 23.33 22.44 22.89 24.44 23.33 22.67 Average Strength (MPa) 16.37 22.89 23.48 28 days Strength W/C Ratio •

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0.55

0.50

0.45

Compressive Strength of M 25 Concrete using Silt as FA

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Compressive Strength of M 30 Concrete using Silt as FA

• Compressive Strength of M 20 Concrete using Sand as FA

7 days Strength W/C Ratio

0.55

0.50

0.45

Sample I

II

III

I

II

III

I

II

III

525

530

535

535

520

690

610

Load Taken (kN) 580

620

Strength (MPa) 25.78 23.33 23.56 23.78 23.78 23.11 30.67 27.11 27.56 •

Compressive Strength of M 25 Concrete using Sand as FA

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Techsynthesis • Compressive Strength of M 25 Concrete using Sand as FA

•

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Compressive Strength of M 30 Concrete using Sand as FA

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• CONCLUSION AND RECOMMENDATION Strength comparison between concrete cubes using Silt and Sand as FA A. For M 20 Grade of Concrete

B. For M 25 Grade of Concrete

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Techsynthesis C. For M 30 Grade of Concrete

From the research work, it has been established that river silt can be used as a replacement of river sand to meet the increasing demand of sand. Use of silt can also reduce the cost of construction of concrete structure hence it also economises the concerting process. Moreover, proper collection of silt may help in channelization of natural stream. REFERENCES : [1] IS Codes

IS 516: 1959 for compressive strength test of concrete



IS 383: 1970 for gradation of aggregate



IS 456: 2000 plain and reinforced cement concrete



IS 14858: 2000 for specifications of compression testing machine



IS 10262: 2009 concrete mix proportioning

[2] M. Usha Rani and J. Martina Jenifer “An experimental study in the partial replacement of sand with crushed brick in concrete” IJSTE (International Journal of Science Technology and Engineering), Volume 2, Issue 08, February -2016 [3] Akshay C. Sankh and Praveen M.Biradur “Recent trends in the replacement of natural sand with different alternatives” IOSR Journal of Mechanical and Civil Engineering, e-ISSN: 2278-1684, p-ISSN:2320-334X,2014

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