Mahatma Gandhi Mission’sCollege of Engineering and Technology.

Noida, U.P., India

Report on Practical Industrial TrainingCarried out at

Pragati power station , New Delhi

From 16-06-14 to 11-07-14.

Acedemic year 2013-2014

Submitted by: Submitted to: Name: ADARSH BHADAURIA Class:BT ME Mechanical Engineering Department, Univ. Roll No:1109540004 MGM’s COET,

Noida

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Mahatma Gandhi Mission’sCollege of Engineering and Technology.

Noida, U.P., India

Department of Mechanical Engineering

CERTIFICATE

This is to certify that Mr. / Ms. ADARSH BHADAURIA of B. Tech. Mechanical

Engineering, Class BT ME Roll No 03. has completed / partially completed / not

completed his / her Industrial Training during the academic year 2013-2014 from

16-06-14 to 11-06-14 at PRAGATI POWER STATION-1,NEW DELHI.

Training Coordinator Head of the Department

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ACKNOWLEDGEMENT

I am a 4th year student from MGM’s college of engineering and technology, Noida (U.P) .I was appointed to do 4 weeks training at this esteemed organization from 16st June 2014 to 11th July 2014.

I was assigned to visit various division of the plant, which were:

Water treatment plant

Gas turbine section

Steam turbine section

This training was a very educational for me. It was really amazing to see the plant by myself and learn how electricity is produced. This report has been made by my experience at PPS-1. The material in this report has been gathered from my textbook and trainers manuals provided by training department. The specification and principles are as learned by me from the employees of each division of PPS-1.

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ABSTRACT

This report contains the working of pragati power station , New Delhi. pragati power station is a combined gas

cycle power plant. It contains two types of power producing turbines namely steam turbines and gas turbines.

These are very well connected and use output of each other at very great extent. The plant also contains water

treatment plant. The gas which is supplied to the gas turbine is supplied by GAIL (gas authority of India

limited). This report also contains all the specifications of power plant.

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TABLE OF CONTENTS

CONTENTS Page no.

CHAPTER-1 About the company 7

CHAPTER-2 Gas Turbine section 10

2.1 Working of gas turbine 11

2.1.1 Principle of operation 12

2.2 Main Components of gas turbine 13

2.3 Air intake system 14

2.3.1 Compressor 15

2.3.2 Combustor 15

2.4 Turbine section 18

2.5 Gas turbine accessory systems 18

2.6 Exhaust system 18

2.7 Auxiliary components of gas turbine 18

2.7.1 Gas turbine starter 19

2.8 Inlet air filters 21

2.8.1 Air filter house 21

2.9 Fan air coolers 22

CHAPTER-3 Steam turbine section 23

3.1 Working cycle 25

3.2 Processes in Rankine cycle 25

3.3 Constructional features 26

3.3.1 H.P. Turbine 26

3.3.2 L.P. Turbine 26

3.3.3 blading 27

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3.3.4 Bearings 27

3.3.5 Shafts glands and Inter stage sealing 28

3.3.6 Valves 29

3.4 Turbine governing system 29

3.5 Turbine motoring system 29

3.6 Technical specifications 30

REFERENCES 31

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LIST OF FIGURES

LIST Page no.

Fig. 1.1 Pragati power station 8

Fig. 2.1 Gas turbine 10

Fig. 2.2 Working of Brayton cycle 11

Fig. 2.3 Components of gas turbine 13

Fig. 2.4 Air intake system 14

Fig 2.5 Compressor House 16

Fig. 2.6 Gas turbine mounted with multi can combustors 17

Fig 2.7 Auxiliary systems of gas turbine 20

Fig. 2.8 Air Filter house 21

Fig. 2.9 Air filters 21

Fig. 2.10 Fan air coolers 22

Fig. 3.1 Steam turbine 23

Fig. 3.2 Steam turbine blading 24

Fig. 3.3 processes in rankine cycle 25

Fig. 3.4 Blading 27

Fig, 3.5 shaft gland and inter stage sealing 28

Fig. 3.6 valves 29

Fig. 3.7 Turbine motoring system 30

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CHAPTER 1

ABOUT THE COMPANY

Fig. 1.1 Pragati power station

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Pragati Power Corporation Limited is an undertaking of Government of NCT of Delhi. It was incorporated on

9th January,2001 to undertake power generation activities for supplying power to Delhi. It is one of the leading

Undertakings of GNCTD, generating profits since inception and paying dividends regularly.It is presently

having capital base of 2,019 crores and asset base of 3,319 crores. The projected asset base and revenue

income of Company in the near future are 6,000 crores and 5,000 crores respectively. The first project

undertaken by the company was 330 MW gas based CCGT which was fully commissioned in the year 2003-04.

The station is presently operating at above 85% availability.PPCL is presently setting up a 1500 MW Gas Based

CCGT plant at Bawana in North-West Delhi to augment the power generation at Load- Centre. Project is

expected to fully commission by July 2011. PPCL is also proposing to put up a 750 MW Gas Based CCGT at

Bamnauli in South-West Delhi. The project is expected to be commissioned in the year 2013-14.

To have reliable supply to the Capital City, a 330 MW combined cycle Gas Turbine Power Project was set up

by PPCL on fast track basis. The plant consists of 2 x 104 MW GE Frame 9-E Gas Turbine Units commissioned

in 2002 – 03 and 1 x 122 MW STG Unit commissioned in 2003 – 04. The station is using APM, PMT and R-

LNG Gas, supplied by GAIL through HBJ Pipeline. The station is performing well and has achieved availability

of more than85%. The power generation from the station is pumped to the adjacent 220kV Sub Station of Delhi

Transco Limited and the entire power is supplied to the discoms of Delhi i.e. NDPL, NDMC, BRPL & BYPL.

The Special features of the plant are as under:

Due to paucity of water in the capital city, the plant is operating on treated sewage water supplied from

Sen Nursing Home & Delhi Gate STPs. The STP water is further treated in RO-DM Plant.

Emission of oxides of Nitrogen (Nox) has been limited to 35 PPM, lowest in the country, for which

special technology is used by installing Dry Low Nox (DLN) Combustors. This is the first plant in India

with a facility to control Nox. Emission.

The plant effluent is discharged to river Yamuna after neutralizing and thus the effluent discharge is

better than river water, making the project eco-friendly.

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CHAPTER 2

GAS TURBINE SECTION

Fig 2.1 Gas turbine

A gas turbine is a rotary machine, which consists of three main components - a compressor, a combustion

chamber, and a turbine. The air after being compressed into the compressor is heated either by directly burns

fuel in it or by burning fuel externally in a heat exchanger. The heated air with or without products of

combustion is expanded in a turbine resulting in work output, a substantial part, about two-thirds, of which is

used to drive the compressor. The rest, about one-third, is available as useful work output. A gas turbine extracts

energy from a flow of hot gas produced by combustion of gas or fuel oil in a stream of compressed air. It has an

upstream air compressor (radial or axial flow) mechanically coupled to a downstream turbine and a combustion

chamber in between. "Gas turbine" may also refer to just the turbine element.

Energy is released when compressed air is mixed with fuel and ignited in the combustor. The resulting gases

are directed over the turbine's blades, spinning the turbine, and mechanically powering the compressor. Energy 10

is extracted in the form of shaft power, compressed air and thrust, in any combination, and used to power

aircraft, trains, ships, electrical generators, and even tanks. The gas turbine at P.P.C.L is of B.H.E.L model MS

9000, is a simple cycle, single shaft gas turbine with a 14 combustion chambers, reverse flow combustion

system. The turbine assembly is consist of following six major sections or groups

2.1 WORKING CYCLE OF GAS TURBINE

Brayton cycle is the working cycle of gas turbine.

Fig. 2.2 Working of Brayton cycle

1-2 isentropic compression (in compressor)

 

2-3  const. pressure heat-addition (in combustion chamber)

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3-4 isentropic expansion (in turbine)

 

4-1 const. pressure heat rejection (exhaust )

2.1.1 Principle of operation

Intake

-Slow down incoming air

-Remove distortions

Compressor

- Dynamically compress air

Combustor

-Heat addition through chemical reaction

Turbine

-Run the compressor

Nozzle/ Free Turbine

-Generation of thrust power/shaft power

Gas turbine essentially consists of following sections:

Primary Section consists of:-

Air Intake system having 784 pairs of cylindrical and conical cartridge filters

Compressor Section having 18 stages of the rotor and starter Blading:

Combustor (Combustion Chamber) consists of 18 combustors cross fire tubes, fuel nozzles, spark plug

igniters and flame detectors.

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Turbine Section having 3 stages

Exhaust system

2.2 MAIN COMPONENTS OF GAS TURBINE

Fig. 2.3 components of gas turbine

2.3 AIR INTAKE SYSTEM

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Fig 2.4 Air intake system

2.3.1 COMPRESSOR

Compressor used in gas turbine is Axial –Flow type

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High Performance Made Possible by Advanced Aerodynamics, Coatings, and Small Blade Tip Clearances

Even Small Amounts of Deposits on Compressor Blades May Cause Large Performance LossesAs air flows

into the compressor, energy is transferred from its rotating blades to the air. Pressure and temperature of the air

increase. Most compressors operate in the range of 75% to 85% efficiency.

2.3.2 COMBUSTOR

The purpose of the combustor is to increase the energy stored in the compressor exhaust by raising its

temperature. Combustion air, with the help of swirler vanes, flows in around the fuel and mixes with the fuel.

This air is called primary air and represents approximately 25 of total air ingested by the engine. The fuel-air

mixture by weight is roughly 15 parts of to 1 part of fuel. The remaining 75 percent of the air is used to form an

air blanket around the burning gases and to lower the temperature.

COMPRESSOR SECTION

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Fig. 2.5 Compressor house

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COMBUSTOR

Fig 2.6 Gas turbine mounted with multi can combustors

2.4 Turbine Section17

The three-stage turbine section is the area in which the energy in the hot pressurized gas produced by

compressor and combustion sections is converted into mechanical energy.

The first stage of turbine rotor blade consists of blades.

Air cooling arrangements are provided for turbine 1st and 2nd stage.

2.5 Gas Turbine Accessory Systems

Starting System To get compressor initially rotated, starting motor provide 6 rpm Then excitation to crank till

700 rpm Once at 400-420 rpm, fuel injected and spark ignited 1 min. warm up time Accelerating mode around

3000 rpm at FSNL Power Transmission System Reduction gears used to transfer torque With split shaft,

turbines can run @ different speeds

 

2.6 Exhaust System

Simple Cycle Stack

Transition to HRSG

2.7 Auxiliary components of gas turbine

There are main three auxiliary components of gas turbine are:

Gas turbine starter

Inlet air filter

Fin- fan air cooler

2.7.1 Gas turbine starter18

The gas turbine requires a starting mechanism to spin the main shaft initially, and once the turbine reaches its

rated speed this mechanism detaches automatically. This starting process normally uses an electric motor to spin

the main turbine shaft. The motor is bolted to the outside of the engine and uses a shaft and gears to connect to

the main shaft. The electric motor spins the main shaft until there is enough air blowing through the compressor

and the combustion chamber to light the turbine. Fuel starts flowing and an igniter similar to a spark plug ignites

the fuel. Then fuel flow is increased to spin the engine up to its operating speed

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Fig. 2.7 Auxiliary systems of gas turbine

2.8 INLET AIR FILTERS20

The air supplied to the gas turbine must be cleaned and conditioned thoroughly and no impurities, dust and

corrosive chemicals should be present in it. For this purpose the atmospheric air is passed through air filter

house that contains a number of small cylindrical filters.

2.8.1 AIR FILTER HOUSE

Fig. 2.8 Air filter house

AIR FILTERS

Fig. 2.9 Air filters

After this the air is passed through fin fan air coolers and air washer system for controlling the temperature and

then to the turbine

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2.9 FAN AIR COOLERS

Gas turbines operate with a constant volume of air flow, but the power they generate is determined by the mass

flow of air. As a result, the denser the air is when it flows through the turbine, the greater that the output power

will be. Warm air is less dense than cold air, and therefore gives a lower power output. In addition, warm air is

harder to compress than cold air, thus requiring greater work from the compressor, leaving less net available

shaft energy.

Fig. 2.10 Fan Air coolers

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CHAPTER 3

STEAM TURBINE SECTION

Fig 3.1 Steam turbine

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A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it

into useful mechanical work. The available heat energy of the steam first is converted into kinetic energy by the

expansion of the steam in suitably shaped passage, or nozzle, form which it issues as a jet, at a proper angle,

against curved blades mounted on a revolving disk or cylinder and by the reaction of the jet itself as it leaves

the curved passage. The pressure on the blades, causing rotary motion, is solely due to the change of

momentum of the steam jet during its passage through these blades.

Fig. 3.2 Steam Turbine blading

The steam energy is converted mechanical work by expansion through the turbine.   The expansion takes place

through a series of fixed blades (nozzles) and moving blades each row of fixed blades and moving blades is

called a stage. The moving blades rotate on the central turbine rotor and the fixed blades are concentrically

arranged within the circular turbine casing which is substantially designed to withstand the steam pressure. On

large output turbines the duty too large for one turbine and a number of turbine casing/rotor units are combined

to achieve the duty.  These are generally arranged on a common centre line (tandem mounted) but parallel

systems can be used called cross compound systems.

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3.1 WORKING CYCLE

The steam turbine works on rankine cycle, the Rankine cycle is a thermodynamic cycle which converts heat

into work. The heat is supplied externally to a closed loop, which usually uses steam as the working fluid. A

Rankine cycle describes a model of the operation of steam heat engines most commonly found in power

generation plants. Common heat sources for power plants using the Rankine cycle are coal, natural gas, oil, and

nuclear.

3.2 PROCESSES IN RANKINE CYCLE:

Fig. 3.3 processes in Rankine cycle

Process 1-2: The working fluid is pumped from low to high pressure, as the fluid is a liquid at this stage the

pump requires little input energy.

Process 2-3: The high pressure liquid enters a boiler where it is heated at constant pressure by an external heat

source to become a dry saturated vapor.

Process 3-4: The dry saturated vapour expands through a turbine, generating power. This decreases the

temperature and pressure of the vapour, and some condensation may occur.

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Process 4-1: The wet vapour then enters a condenser where it is cooled at a constant pressure and temperature

to become a saturated liquid. The pressure and temperature of the condenser is fixed by the temperature of the

cooling coils as the fluid is undergoing a phase-change.

3.3 CONSTRUCTIONAL FEATURES

The steam turbine at P.P.C.L has a tandem compound shaft arrangement with H.P and L.P section

3.3.1 H.P turbine:

The H.P turbine is of single flow, double shell construction with horizontally split casings allowance is made

for thermal movement of the inner casing within the outer casing. The main steam enters the inner casing from

top and bottom.

3.3.2 L.P turbine:

The casing of the double flow L.P turbine is of three shell design. The shells are of horizontally split welded

construction. The inner casing which carries the first rows of stationary blades is supported on the outer casing

so as to allow for thermal expansion.

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3.3.3 BLADING

Fig 3.4 Blading

The entire turbine is provided with reaction blading. The moving blades of H.P turbine and the initial rows of

L.P turbine with inverted T roots and integral shrouding are machined from solid rectangular bar.

3.3.4 BEARINGS

The H.P rotor is supported on two bearings a combined journal and thrust bearing at its front and a journal

bearing close to the coupling with L.P motor. The L.P rotor has a journal bearing at its end. The combined

journal and thrust bearing takes up residual thrust from both directions

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3.3.5 SHAFT GLAND AND INTERSTAGE SEALING:The shaft gland seals the steam inside the cylinders against atmosphere and the interstage seals restrict leakage

at blade tip

.

Fig. 3.5 Shaft gland and interstage sealing

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3.3.6 Valves: Steam enters the turbine from the HRSG into a series of valves. These valves are controlled

by the governor with regulates the amount of steam passing through the turbine in order to maintain the constant

speed required to generate power at 50 cycles per second.

Fig.3.6 valves

3.4 Turbine governing system

The turbine has an electro-hydraulic governing system backed up with a hydraulic governing system.

Anelectric system measures and controls speed, output and operate the control valves hydraulically in

conjunction with an electro- hydraulic converter.

3.5 Turbine monitoring system

In addition to the measuring instruments and instruments indicating pressures, temperatures, valves positions

and speed, the monitoring system also includes measuring instruments and indicators for the following values:

Differential expansion between the shafting and turbine casing.

Bearing pedestal vibrations, measured at all turbine bearings.

Relative shaft vibrations measured at all bearings.

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Fig. 3.7 Turbine motoring system

3.6 Technical specification:

H.P turbine : Single flow with 28 reaction stages.

L.P turbine : Double flow with 8 reaction stages.

Main stop and control valves : 2

L.P stop and control valves : 2

Speed:-

Rated Speed : 50.0/s

Max. Speed no time limitation : 51.5/s

Min speed no time limitation : 47.5/s

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REFERENCE

Books at PPS-1 LIBRARY. Internet

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