AN INDUSTRIAL TRAINING REPORT – I

Done by

SASHIKANT TIWARISAP ID.:500041217

Roll No.:R630214066

At

Rosa Power Supply Company Ltd.Administrative Block, PO-Rosar Kothi, Sadar Tehsil

Shahjahanpur, Uttar Pradesh: 242406

Submitted to

Department of Electrical and Power EngineeringUniversity of Petroleum and Energy Studies

Energy Acres Dehradun,Uttrakhand

1

BONAFIDE CERTIFICATE

Certified that this Industrial Training Report – I is a work of

SASHIKANT TIWARI (RollNo.R630214066) who carried out the work at Rosa

Power Supply Company Ltd., Administrative Block, PO-Rosar Kothi, Sadar

Tehsil, Shahjahnpur, Uttar Pradesh

Mr. Chandra Shekhar Mr. B.S. Prasad

Head- Simulator & Training Station Director

2

3

4

5

Acknowledgement It is always a pleasure to remind the fine people in the Engineering program for their sincere guidance I received to uphold my practical as well as theoretical skills in engineering.

Firstly I would like to thank Mr Narendra  Balkishan Soni (Head of Department, Dept. of Electrical and Power Engineering, UPES) for meticulously planning academic curriculum in such a way that students are not only academically sound but also industry ready by including such industrial training patterns.

I would also like to thanks Mr Ram Mohan Sharma (Group In-charge) for the positive attitude he showed for my work, always allowing me to question him and giving prompt replies for my uncertainties.

Finally, I would also like to thanks Mr. Chandra Shekhar (Head-Simulator & Training), Mr. B.S. Prasad (Station Head) for giving me this opportunity and guiding during the course of the training.

6

CONTENTS

Chapter No Topic Page No.

1. Introduction 7

2. Details of the Industrial Training

2.1 Simulator Training 8

2.2 Maintenance Training 8

3. Details of study

3.1 Simulator Training 9-14

3.2 Maintenance Training 15-27

4. Conclusions 27

7

CHAPTER 1

INTRODUCTION

Rosa Power Plant is a 1200 MW of coal based generation capacity at Rosa village in Shahjahanpur, Uttar Pradesh. The power plant is being developed in two stages with the first stage already having become commercially operational on 12 March 2010. It is also the first project of the company operational. Rosa Power Supply Company Limited (RPSCL), the holding company of Rosa Power Plant was incorporated on September 1, 1994 as a subsidiary of Aditya Birla Power Company. It was later transferred to Reliance Power on November 1, 2006 and is now fully owned subsidiary of Reliance Power. It is a project that has received a considerable support from the Uttar Pradesh government with it being designated a ‘Priority project’. The Entire power generated will be sold to Uttar Pradesh Power Corporation Limited (UPPCL).There are total 4 units in operation with individual capacity of 300 MW.

8

CHAPTER 2

DETAILS OF INDUSTRIAL TRAINING

2.1SIMULATOR TRAINING:

9

The simulator training held for seven days at RPSCL, Sahajhanpur Uttar Pradesh. Simulator is an imitation of the actual software that is being used to control a single unit i.e., 300 MW in case of RPSCL. During the simulator training we have been given the task of reaching to 300 MW at the end of seven days. From the first day itself we have taught about the basic operation of Rosa Power Plant along with its operation specification. Then we learned about all those equipment’s which are used in thermal power plant there operation and they controlled and maintained with the help of simulator. Then we come to know the conditions that need to be satisfied in order to a device working. With these small steps we finally reach 300 MW at the very last day.

2.2MAINTENANCE AND PROTECTION TRAINING:

The training held for 3 days after the simulator training at RPSCL, Sahajhanpur Uttar Pradesh. During this training we make the site visit to switchyard, Boiler, Turbine, Steam Drum and Feeders. Theory classes held for the same. In theory classes we came to know about types of maintenance and testing for different equipment’s.

Simulator Training

Electrical Charging;

10

This is a process of charging all the auxiliaries from the grid. In any Power Plant all your auxiliaries need to start first for that electric charging is done. All 6.6 KV, 415V, 220V DC, UPS & emergency power supply (DG) are available & buses are charged.

220 KV-6.6KV-415V

Auxiliary Cooling Water;ACW pumps are started first followed by air compressor. Ensure that coal-handling system is ready. Ensure ash-handling system is ready for ash evacuation. Ensure that all soot blowers are in non -operating position. Start CW (Cooling Water) & CCW (Condensate Cooling Water) system and charge all the associated systems. Open drum, MS drain after stop valve & start up vents.Start ID/FD fans and maintain furnace draft at -1 mmwc.

Purging;Fulfil all the purge permissive and purge the boiler. Boiler purging will take exactly 300 seconds or 5 minutes. Carry out HFO and LDO leak test if required, otherwise bypass the test.Primary Purge conditions;

i. MFT activeii. All burner oil valves and its purge valves, atomizing steam/

air valves closediii. All pulveriser stoppediv. All coal feeders stoppedv. All pulveriser outlet dampers closed

vi. All Primary Air fan stoppedvii. Any Air Pre- heater running

viii. Any induced draft fan running

11

Secondary Purge Conditions;ix. Total air flow rate between 30% and 40%x. Boiler drum level normal (between -150mm to 150mm)

xi. Furnace pressure normal (between -300Pa and 300Pa)xii. Fuel oil leak test (HFO & LDO) success or test bypassed

Boiler Lighting;Light up the boiler with BC elevation and allow it to run for next 15 min. Take all the guns at BC elevation in service after 30 minutes & raise the drum pressure & temperature.

Starting of Turbine;Start main Turbine oil, Jacking oil & Seal oil system. Charge hydrogen system and ensure that hydrogen pressure 3 bar. Charge Generator cooling water system with one pump in service. Start turbine barring gear RPM- 2.56. Ensure that all the HP-IP drains, valve chamber drains are open. Put AB elevation guns in service. Switch over the soot blowing medium from air to steam APH.

Seal Oil;Take second streams of ID & FD fans in service. Close HP/LP bypass. Regulate the pressure. Ensure all turbine drains are in open condition. Start seal Oil back up pump and check that the discharge pressure.

Rated hydrogen pressure 0.31 MPa

12

Seal oil to hydrogen diff pressure 0.084 MPa

Air side seal oil AC motor rating 15 KW

Air side seal oil DC motor rating 10 KW

Gas side seal oil AC motor rating 4 KW

Hydrogen side seal oil STD by AC motor rating

30 KW

Turbine Rolling;Rolling parameters achieved. Close all HP-LP bypasses. Bypass mode off then roll. Latch all Guide vanes (GV’s) & Transfer Vanes(TV’s). Set the target and ramp rate of i. 600 rpm, 100 ii. 2040 rpm, 100 iii. 2950 rpm, 100 and TV-GV transfer after that, iv. 3000 rpm, 50

Synchronization;Open earth switch, close isolators. Check the readiness of generator. Exciter (ON), 20 KV.DEH-CNTL mode, auto sync, in service. Start synchronizing.

Load Raising;Set the target load at 30 MW. Select the load rising rate of 1 MW/min. Start Primary Air fan. Start seal air fan. Light up the mill system. Take new mill in service & raise the firing rate. Now set target and change over at 40 MW.

13

Set the target load at 105 MW. Select the load rising rate of 1.5 MW/min.Load will reach to 105 MW in the next 30 minutes if firing rate is regulated properly. At 15% of rated load (45 MW), Close all the drains of HP cylinder. At 20% of rated load (60 MW), Close all the drains of IP cylinder. At 30% of rated load (90 MW), Close all the drains of LP cylinder. Take Mill C in service at 40%load & raise the firing rate. At 180 MW, Ensure that main steam pressure & temperature is 130 bar & 537 Deg. C.Take Mill D in service at 60% load & raise the firing rate.Set the target load at 225 MW. Select the load rising of 2 MW/min.At 225 MW, Ensure that main steam pressure & temperature is 158 bar & 537 Deg. C. At 240 MW, Ensure that main steam pressure & temperature is 167 bar & 537 Deg. C. Full load 300 MW achieved.RECOMMENDED TIME TO BRING BOILER ON FULL LOAD

After cold start (72 hour shut down)

Hour <7.5

After 36 hrs. Shut down

Hour <4

After 8 hrs. shut down

Hour <1.5

Hot restart (Less than 1 hour after shut down)

Hour <1.0

Control Point of Boiler

Hour 60-100% BMCR for re -heaters and 50-100% BMCR for super heaters

14

Mill System; All feeder in auto ( Biasing if required), Fuel master in Auto & Remote

Unit CCS; See base load in boiler follow mode, # Pre- set point in fix mode # Take fuel master in remote #Send DEH Request

DEH; Take MW loop out # Control mode- Remote in Unit CCS; See DEH in remote, # Put DEH master in auto, # Than

give MW set point.

Levels;

System Description

Low Low (mm)

Low (mm)

Normal (mm)

High (mm)

High High (mm)

Very Very High (mm)

Deareator -500 NA >-500 & <500

500 1200 1400

CCW expansion tank

<300 <750 >800 >1050 >1200 NA

Hot well 150 250 676 710 1120 1600

HP-LP Bypass oil tank

130 220 >220 NA 560 NA

EH oil tank 290/190

438 >438 NA 560 NA

MOT <-543 <-152 >-152 >152 NA NA

Stator water tank

NA <550 >600 >700 >750 NA

15

Hydrogen seal oil tank

NA <-100 >-100 NA NA NA

HP heater-8 NA -630 -592 -554 -504 -454

HP heater-7 NA -630 -592 -554 -504 -454

HP heater-6 NA -554 -516 -478 -428 -378

LP heater-4 NA -462 -424 -386 -336 -286

LP heater-3 NA -462 -424 -386 -336 -286

LP heater-2 NA -609 -571 -553 -485 NA

LP heater-1 NA -609 -571 -553 -485 NA

Mill Lube oil tank

NA <200 >200 NA NA NA

FD fan lube oil tank

NA <200 >200 NA NA NA

16

Maintenance & Protection Training Boiler Design;

Max Boiler Column Height

73m

Total No of Columns 33No.s

Total No of ceiling Girder 10No.s

Total Weight of Boiler Structure

3000 tons

Weight of Drum 218335 Kg

Total weight of pressure parts

3237 MT

Other Non- Pressure Parts 4129 MT

Furnace Dimensions (W*D*H)

16100x14120x40820

Max weight of Ceiling Girder (L-Row)

60 MT

Name of Boiler- Sub critical, Single Drum, Natural Circulation, Single reheat, Dry Bottom, Two Pass, Balanced Draft, Semi Outdoor

17

Boiler Protections;

Protections Trip value

Both of the emergency push button presses by operator

NA

Furnace pressure high high 20mbar

Furnace pressure low low -20mbar

Drum level high high 250mm

Drum level low low -350mm

Both FD fan stopped NA

Both ID fan stopped NA

Both APH stopped NA

Scanner fan pressure low low 32.3mbar

Total air flow 300 TPH

Loss of all fuel NA

Loss of all flame NA

18

Turbine Protection;

PROTECTION ALARM VALUE TRIPPING VALUE

EH oil pressure low 110 Bar 93.1 Bar

Lube oil pressure 1.0 Bar/ 0.85 Bar 0.35 Bar

Vacuum low -0.87 Bar -0.80 Bar

HP exhaust pressure high

40 Bar 48 Bar

Over speed NA 3250/3330

Rotor position -0.9/0.9 mm -1/1 mm

Rotor vibration 127 microns 254 microns

Differential expansion

-0.6/12.7 mm -1.4/13.4 mm

HP exhaust ratio NA <=1.728

HP exhaust temperature

400 Deg. C 427 Deg. C

Bearing temperature high

From 1 to 4-98 Deg. C

From 1 to 4-107 Deg. C

MFT NA Load>180 MW

Manual trip NA NA

DEH power lost NA NA

19

Isolators; Isolator switch is used to ensure that an electrical circuit is completely de-energized for service or maintenance.

Circuit Breaker; It is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overcurrent or short circuit.

Types of Circuit Breakers;I. Vacuum Circuit Breaker- In vacuum circuit breakers,

vacuum is used as the arc quenching medium. Since vacuum offers the highest insulating strength, it has far superior arc quenching properties than any other medium.When the contacts of circuit breaker are opened in vacuum an arc is produced b/w the contacts by the ionisation of metal vapours of the contacts. However the arc is quickly extinguished because the metallic vapours, electrons and ions produced during arc rapidly condensed on the surface of CB contacts, resulting in quick recovery of dielectric strength.

II. SF6 Circuit Breaker- In such circuit breakers SF6 gas is used as the arc quenching medium. The SF6 is an electro-negative gas and has a strong tendency to absorb free electrons. The contacts of the breaker are opened in a high pressure flow of SF6 gas an arc is struck b/w them. The conducting free electrons in the arc are rapidly captured by the gas to form relatively immobile negative ions. This loss of conducting electrons in the arc quickly builds up enough insulation strength to extinguish the arc.

Maintenance;

20

Maintenance, repair, and operations involve fixing any sort of mechanical, plumbing or electrical device should it become out of order or broken (known as repair, unscheduled, or casualty maintenance). It also includes performing routine actions which keep the device in working order or prevent trouble from arising.

Any activity- such as tests, measurements, replacements, adjustments and repairs- intended to retain or restore a functional unit in or to a specified state in which the unit can perform its required functions.

For material- all action taken to retain material in a servicing, classification as to serviceability, repair, rebuilding, and reclamation.

For material- all supply and repair action taken to keep a force in condition to carry out its mission.

For material- the routine recurring work required to keep a facility in such condition that it may be continuously used, at its original or designed capacity or efficiency for its intended purpose.

Vibrations;Vibration can result from a number of conditions, acting alone or in combination. Keep in mind that vibration problems might be caused by auxiliary equipment, not just the primary equipment.

i. Imbalance- A heavy spot in rotating component will cause vibration when the unbalanced weight rotates

21

around the machine’s axis, creating a centrifugal force. Imbalance could be caused by manufacturing defects or maintenance issues. As machine speed increases the effects of imbalance become greater. Imbalance can severely reduce bearing life as well as cause undue machine vibration.

ii. Misalignment run out- Vibration can result when machine shaft are out of line. Angular misalignment occurs when the axes of a motor and pump are not parallel. When the axes are parallel but not exactly aligned, the condition is known as parallel misalignment. Misalignment can be caused during assembly or develop over time, due to thermal expansion; components shifting or improper reassembly after maintenance.

iii. Wear- As components such as ball or roller bearings drive belts or gears become worn, they might cause vibration. When a roller bearing race becomes pitted, for instance, the bearing rollers will cause a vibration each time they travel over the damaged area. A gear tooth that is heavily chipped or worn, or a drive belt that is breaking down, can also produce vibration.

iv. Looseness- Vibration that might otherwise go unnoticed can become obvious and destructive if the component that is vibrating has loose bearings or is loosely attached to its mounts. Such looseness might or might not be caused by the underlying vibration.

Shaft alignment;

22

Shaft alignment is the process of alignment two or more shafts with each other to within a tolerated margin. It is an absolute requirement for machinery before the machinery is put in service.When a driver like an electric motor or a turbine is coupled to a pump, generator, or any other piece of equipment, it is essential that the shafts of the two pieces are aligned. Any misalignment between the two increases the stress on the shafts and will almost certainly result in excessive wear and premature breakdown of the equipment. This can be very costly. When the equipment is down, production might be down. Also bearings or mechanical seals may be damaged and need to be replaced. Flexible couplings are designed to allow a driver to be connected to the driven equipment. Flexible coupling use an elastomeric insert to allow a slight degree of misalignment.

Types of misalignment- Picture 1: Offset, or parallel- the shafts are parallel to each

other, but are not co-planar, or in the same plane. This can be both vertical and horizontal. Offset or Parallel misalignment is measured in thousandths of an inch, also called mils

23

Picture 2: Angular- the shafts are not in the same plane, which causes a difference in measurement between measurements made 180 degrees opposite on the coupling faces. Angular Misalignment is measured in thousandths of an inch, or mils, per inch of coupling diameter.

Power Transformer (370 MVA, 230/20 KV);Generation of electrical power in low voltage level is very much cost effective. Theoretically, this low voltage level power can be transmitted to the receiving end. This low voltage level power if transmitted results in greater line current which indeed causes more line losses but if the voltage level of a power is increased, the current of the power is reduced which causes reduction in ohmic or I^2*R losses in the system, reduction in cross sectional area of the conductor i.e. reduction in capital cost of the system and it also

24

improves the voltage regulation of the system. Because of these, low level power must be stepped up for efficient electrical power transmission. This is done by step up transformer at the sending side of the power system network. As this high voltage power may not be distributed to the consumers directly, this must be stepped down to the desired level at the receiving end with the help of step down transformer. Electrical power transformer thus plays a vital role in power transmission.

Some of the important parts of Transformer;

25

Conservator- The conservator conserves the transformer oil. It is an airtight, metallic, cylindrical drum that is fitted above the transformer. The conservator tank is vented to the atmosphere at the top, and the normal oil level is approximately in the middle of the conservator to allow the oil to expand and contract as the temperature varies. The conservator is connected to main tank inside the transformer, which is completely filled with transformer oil through a pipeline.

Breather- The breather controls the moisture level in the transformer. Moisture can arise when temperature variations cause expansion and contraction of the insulating oil, which then causes the pressure to change inside the conservator. Pressure changes are balanced by a flow of atmospheric air in and out of the conservator, which is how moisture can enter the system. If the insulating oil encounters moisture, it can affect the paper insulation or may even lead to internal faults. Therefore, it is necessary that the air entering the tank is moisture-free. The transformer’s breather is a cylinder that is filled with silica gel. When the atmospheric air passes through the silica gel of the breather, the air’s moisture is absorbed by the silica crystals. The breather acts like an air filter for the transformer and controls the moisture level inside a transformer.

26

Tap Changer- The output may vary according to the input voltage and the load. During loaded conditions the output terminal decreases, whereas during off- loaded conditions, the output voltage increases. In order to balance the voltage variations, tap changers are used. Tap changers can be either on-load tap changers or off-load tap changers. In an on-load tap changer, the tapping can be changed without isolating the transformer from the supply. In an off- load tap changer, it is done after disconnecting the transformer.

Cooling Tubes- Cooling tubes are used to cool the transformer oil. The transformer oil is circulated through the cooling tubes. The circulation of the oil may either be natural or forced. In natural circulation, when the temperature of the oil rises the hot oil naturally rises to the top and the cold oil sinks downward. Thus the oil naturally circulates through the tubes. In forced circulation, an external pump is used to circulate the oil.

27

Buchholz Relay- The buchholz relay is a protective device container housed over the connecting pipe from the main tank to the conservator tank. It is used to sense the faults occurring inside the transformer. It is used to sense the faults occurring inside the transformer oil during internal faults. It helps in sensing and protecting the transformer from internal faults.

28

Explosion Vent- The explosion vent is used to expel boiling oil in the transformer during heavy internal faults in order to avoid the explosion of the transformer. During heavy faults, the oil rushes out of the vent. The level of the explosion vent is normally maintained above the level of the conservatory tank.

Chapter 3

Conclusions

The 10 days spent in Rosa Power Plant Ltd. has been a unique experience to me. It was an eye opener to how a coal based thermal power plant actually works in real. This training gives the exposer to both Simulator work and on-field work. Through practical training, I have gain a great learning to systematic work coordination in an environment that is conducive coupled with friendly staff that is always there to help.

29