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INDEX

ACKNOWLEDGEMENT

INTRODUCTIONNTPC AT FARIDABAD GENERAL LAYOUT OF FGPS

BASIC WORKING OF PLANT

RAW MATERIAL AND PROCUREMENT

THE GAS TURBINE(GT)

WASTE HEAT RECOVERY STEAM

GENERATOR(WHRSG) STEAM TURBINE(ST)

CONTROL AND INSTRUMENTATION

CONTROL AND MONITORING MECHANISM

CONTROL VALVES

TEMPERATURE MEASUREMENT

FLOW MEASUREMENT

MECHANICAL MAINTENANCE


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ACKNOWLEDGEMENT

I would like to express my deep sense of gratitude to the NTPC

LIMITED FARIDABAD for extending me the opportunity for the

vocational training & providing all the necessary resources and

expertise for this purpose.

I owe my special thanks to Mr.R.K. Niranjan ( training incharge),

faridabad gas power station for his constant & wonderful support.

I am highly grateful to Mr.Dhiraj Kr. girdhar & Mr. Amit tyagi,

faridabad gas power station whose encouragement & cooperation

has been a great source of inspiration. I also express my heartfelt for

there enthusiastic cooperation to make my training possible & all

other employs of NTPC for there painstaking efforts and constant

guidance to make my training possible in best possible manner.

I would like to thanks faridabad gas power station for providing meall the facilities for the timely completion of our training


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INTRODUCTION :

NTPC Ltd. (NTPC) INDIAS PRIME POWER HOUSE

NTPC, Indias largest power utility that wasincorporated in 1975 with prime objective of playing amajor role in the Indian power sector.

A public company wholly owned by the government ofIndia.

Within a span of 30yrs, NTPC has emerged as a trulynational power company, with power generating

facilities in all the major regions of the country. Today NTPC is having an installed capacity of 39171

MW.

The corporation has been ranked the 15th largestpower generator & 6th largest thermal power generatorglobally.

NTPC aims to be a 40,000 MW giant by year 2012. Operating 13 coals based &7 gas based stations,

NTPC with its share of about 20% of Indias totalinstalled capacity to generate 30% of total generationIndia.

NTPC is committed to environment, generating powerat the minimal environmental cost& preserving theecology in the vicinity of the plants.

The massive forestations in NTPC & around its

ramagundam power station have contributed inreducing temperature in the areas by around 3 C.

NTPC has also taken protective steps for ashutilization.

The quality of ash produced is ideal for use in cement,concrete, cellular concrete building material.


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NTPC was among the first public sector enterprises toenter in memorandum of understanding (MOU) with thegovt. of India in 1987-88.

NTPC has been placed under the excellent category

every year since the MOU system operative.

Inspired by a glorious past & brilliant present, NTPC isheading towards a brighter tomorrow.

Every milestone achieved is a dream comes true for its24,000 dedicated employees working in its plantsacross the country

NTPC AT FARIDABAD

LOCATION FARIDABAD, HARYANA

GOVERNMENT APPROVEDDATE

25.07.1997

PLANT CAPACITY 432MW (NOMINAL)

PLANT CONGIGURATION 2 (GAS TURBINES+ WASTEHEAT RECOVERYSYSTEM)+ 1 STEAMTURBINE

GAS

TURBINE=143MWSTEAM

TURBINE=156MW

LAND AVAILABILITY 324.58ACRES available


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To make power available in over increasing quantities,Faridabad Gas Power Project is an economical powerproject.

It will also contribute to over all the developments of thepower sector & thereby assist in economic developmentof power sector.

Ever since the foundation stone laid down on 3rd aug,1997 by honorable Prime Minister Sh. I.K. gujral, theproject has traveled a long distance.

The two gas turbine & one steam turbine are already inoperation.

The natural gas required by the two turbines is suppliedby the Gas Authority of India Limited (GAIL) throughconnection taken from the HBJ pipeline chain terminal.

GAS SOURCE HBJ PIPELINE

WATER SOURCE RAMPUR DISTRIBUTARIESOF GURGAON CANAL

FINANCING OECF,JAPAN

PROJECT COST Rs 1163.60 CROREBENIFICIARY STATES HARYANA (100%)

COMMISSION DATE GT-1: JUNE 1999GT-2: OCTOBER 1999ST:JULY 2000

INTERNATIONALASSISTANCE

OECF


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These gas turbines can also be fired on by naphtha fuelin case of restriction of gas supplies so that continuouspower generation is ensured.

the exhausted gas from turbines will have enough heatto be circulated through the heat recovery steamgenerators & generated steam in turn runs the steamturbine.

GENERAL LAYOUT OF THE FGPS

The whole plant is mainly subdivided into three separatedivisions. They are:

1. Main building2. Main Generating Unit

3. Off-sites

1. MAIN BUILDING:

The main building in the plant are-

(A)ADMINISTRATIVE BUILDING: This building ofthe plant have all the departments other than of plant

maintenance & operation, such as Human Resource(H.R.), Finance & accountants ,Sales ,Safety,Resettlement & Rehabilitation ,library, TelephoneExchange , Material Management & Control,Contracts , Purchase & Store & EDP(the maintraining department).


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(B) SERVICE BUILDING: This building mainlyconsists of maintenance & operations departments &all other which directly deals with functioning of theplant & all other technical jobs. It has departmentsuch as:E.M. (Electrical Maintenance), MM 1&2 (mechanicalmaintenance), O&M (operation & maintenance) &Stores

2. MAIN GENERATING UNIT:This unit comprisesof main functioning plant with all its equipments beingcontrolled from CCR(Common Control Room) of the plant.

3.OFF-SITES: These comprises all other units which otherwise

are very much necessary in the proper working of the maingenerating unit. They are:

a) BFP Buildingb) Chlorination plant

c) CW plantd) PT plante) ET plantf) DM Plantg) Fire water pump househ) CMB Planti) Black starts generating unit

j) Naptha & Dieseel supplying unit

k) Workshopl) air compressor & air washer unitm) gas authority og India Ltd.

Above are necessary departments of the plant which areresponsible for the generation & fuel required in the plant


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while other than these plants one of the major unit responsiblefor the transmission of the electricity to all the requiredcustomers is being done by a separate unit known as NationalThermal Power Cooperation.

BASIC WORKING OF THE PLANT

I. The fuel (natural gas) is feed to the gas turbine.

II. fuel is burnt in the gas turbines to release fluegases at high pressure & temperature whichrotates the shaft of the gas turbines,

III. The shaft of the turbine is linked to the rotor of thegas turbine generator which leads to theproduction of electricity at two generators.

IV. The flue gases produced in step II are passed tothe waste heat recovery steam generators whereit passes through super heaters, evaporates,economizers & condensate pre heater.


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V. Water present & in the above devices absorbsheat from the hot flue gases & gets converted into

high pressure & low pressure steam.

VI. The high pressure steam generated in WHRSG ispassed to HP turbine.

VII. The steam available at the outlet of the HP turbine& the LP turbine generated in the WHRSG are

supplied to the LP turbines.VIII. In step VI & VII the steam supplied to the HP & LP

turbines rotates the respective rotor of the turbine.

IX. These rotors are to the rotor of the steam turbine

generator by rigid couplings. Therefore due to therotation of the turbine rotors the generator rotoralso rotates thereby producing electricity at thegenerator.

These steps are incorporated in the productionof432 MW of electricity from the three units.the main generating unit consist of the followingequipments in the main plant as:


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Two gas turbines

One steam turbine

WHRSG

Raw material and procurement

LandAs an estimate, 4 acre land per unit MWproduced is required. So for a 432 MW plant about

1700 acres of land are required which has been

provided by government of Haryana with an agreement

that all electricity produced will be supplied to Haryana

only.

Water- It obtains its water from nearby Agra Canal.It pays a water cess for the purpose.

Gas fuel - There are 4 types that NTPC Faridabad

uses

APM : Administered Price Mechanism Gas ,

which is government controlled and itsextraction and transporting is looked after by

ONGC

PMT : Panna Mukta Tapti , this gas gets its

name from its basins


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RCNG or RLNG (not sure)

KG Basin : Krishna Godavari Basin

All these gases are provided to the plant by GAIL(Gas Authority of India Limited) which is transporter

of gas that is obtained at ONGC (Oil and Natural

Gas Corporation) platforms

Liquid Fuel - The plant uses two types of Liquid

Fuels:

HSD: High Sulphur Diesel. It is obtained from

IOCL (Indian Oil Corporation Limited).

Tankers containing HSD reach the plant and

store it one 5000 KL tank dedicated for HSD.

Naphtha: It is obtained through a dedicated

pipeline for NTPC Faridabad and is stored intwo 8000 KL tanks.

Chemicals - Variety of chemicals for water treatment

and for auxiliary machinery and various other

purposes are bought from other industries through

tendering. Air - The oxygen required for combustion is

obtained from the atmosphere

.


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Structure

Faridabad gas power plant there are six major

components.

Gas Turbines

Steam Turbines

Generator

Boilers

Switchyard

Switchgear

Besides the Six Major Components, there are

numerous auxiliary machinery which aide the major

components in working perfectly, for instance Fans ,

Radiators , Pumps and many more things.

ProcessThe Gas Fuels fire the two Gas turbines (GT1 and

GT2) which are coupled to individual Generators and

have individual boilers (B1 and B2) at their outlet.


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The steam from the outlet is heated in the boiler and

both the boilers together feed the Steam Turbine

(ST) which is again coupled to another Generator.

The output of the three generators is collected and ispassed onto the adjacent switchyard, and from there

the electricity produced is transmitted to DHVBN

(Dakshin Haryana Bijli Vitran Nigam) and a part of

electricity is used for plants working

Controlling

There exists a dedicated control system at the plantthat uses latest Equipments, Sensors and Technologyto monitor everything that goes on in the plant likevibrations in turbines while running, boiler inlettemperature, turbine inlet out let temperature

FUELS

Gas turbines are capable of burning a range of fuelsincluding naptha, distillates, crude oils & natural gas.Selection of fuels depends on several factors including fuelavailability, fuel cost & cleanliness of fuel. Natural gas is an

ideal because it provides high thermal efficiency & reliabilitywith low operation & maintenance cost. Liquid fuels,particularly heavy oils, usually contain contaminants, whichcan not be removed from the fuel & may leave deposits ingas turbine, which reduce performance & add tomaintenance costs.


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NATURAL GAS

Natural gas is ideal fuel for use in GT s. It contains

mainly Methane (CH4), Ethane (C2H6), Nitrogen (N2),Carbon dioxide (CO2) & Sulphur. It has the followingadvantages.

Clean burning

Availability at lower cost

practically free from solid residue

high calorific value Low sulphur content

NAPTHA

Naptha is one of the fuels used in faridabad gaspower plant. It is actually the substitute fuel which isused in the plant when there is storage of natural gaswhich has more calorific value, i.e. it is more efficient touse natural gas as compared to naptha. naptha is highinflammable and it makes the highly explosive mixturewith the air. so it is very dangerous to use this fuel

without proper instructions and flushing process toremove the air present in the pipe line through whichnaptha is to be transported to the combustion chamber.this is done by firstly sending high speed diesel throughthe pipelines for the removal of any air that may bepresent in the pipelines.


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whenever there is storage of natural gas, naptha is used.it has lesser calorific value than natural gas,but there isno other alternative fuel, therefore it is used. it is also

cheaper than any other fuel and the amount of fluegases that comes out from naptha is nearly equal to theflue gases coming out from the natural gas.

THE GAS TURBINE

The gas turbine is a single shaft (in line to thecompressor unit) ,50hz,135MW machine that runs onnatural gas can also be operated on liquid naphtha .The shaft of the gas turbine is connected to gas turbinegenerator

According to the direction of the flow of air gas turbine,compressor is placed first, combustion chamber isplaced second and turbine is placed at the end ofturbine unit.


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Two bearings are providing to support the shaft of themachine, one of the is provided at the compressor startand the other is laced at the turbine end. The shaft of

the unit is provided with blades in the turbine region.

Basics parts of the gas turbine are:-A: Compressor: - The compressor is the flue gas axialtype. The compressor is provided with the variable inletguide vane system to enable efficient operation. Filteris provided is provided at the top of the compressed tofilter any unwanted material from entering into the

Turbine in the compressor region there are sixteenstages blades. Once set of the blade on the shaft andonce set of fixed blades complete one stage of blades.B: Combustion Chamber: - There are two combustionchambers in the GT, one on each side of the shaft andparallel to each other. The combustion chambers arecylindrical in shape and attached unit in between the

compressor and the turbine. At the top of eachcombustion chamber eight burners are provided forburning the fuel the internal layer of the combustionchamber is lined with tiles to provide insulation and aman hole is provided at the bottom of each combustionchamber cleaning and inspection purposes.C: Turbine: - The turbine is provided at the end of theGT unit. The turbine consists of four stages of blades.It also has bearings to support the shaft at its end

INTAKE AND EXHAUST SYSTEM


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A typical intake and exhaust system for a industrial gasturbine comprises of the following

Intake system:-A: Intake air filterB: Intake air silencerC: Intake air duct

EXHAUST SYSTEM:-A: Exhaust ductB: Expansion joint

C: DampersD: Exhaust silencerE: Bypass stack

Working of gas turbine

During the startup procedure the generator acts as amotor the generator is given supply and thecompressor start working.

The function of compressor is to supply at highpressure to the combustion chamber once in the fairsupply is provided in the combustion chamber the fuel

is ignited. Due to ignition of the fuel, the flue gases atthe high temperature and high pressure is releasedand the thermal expansion of the gases rotates theturbine blades that are connected to the shaft. Theback supply of the generator is then stopped. Fuelssupply is then slowly increased till the optimum speed


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of the turbine is reached once a turbine reached theoptimum speed (30000rpm), The fuel supply is keptconstant. The flue gases after leaving the turbine can

be directed to wards the WHRSG using diverterdamper and gelotine gate.

WASTE HEAT RECOVERY STEAM GENERATOR

waste heat recovery stream generators are unfiredheat recovery type design to accept the maximumexhaust temperature and flue gas flow of the turbine. Ithas no circulation. There are two different type ofsteam produced in this unit(hp & lp).

Basic parts:

1.condensate pre-heater:- it is present at end of theWHRSG. it is added to lower the temperature of the


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flue gases and also to increase the thermal efficiencyof the plant as more heat is absorbed in this type ofprocedure. It consists of spiral fined tubes welded

together to the top and bottom headers. There aremaximum rows per module.

2.Economisers:-there are two different types ofeconomizers present in the WHRSG. These are:-

*LP Economizers:-there are tubes which act aseconomizer of the LP steam, these are spiral finnedtubes welded to the top and bottom headers and fullydrainable design.

*HP Economizer:-in it also there are tubes acts aseconomizer for the HP steam, they also have spiral

finned tubes welded to the top &bottom headers andhave a fully drainable design.

3.EVAPORATORS:-there are two types of evaporatorsthey are

*LP evaporators:- the tubes act as evaporators for theLP steam, these are connected to the lp drum and alsospiral finned tubes.


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*HP Evaporators:-tubes acts as evaporators for the HPsteam and are placed closer to the turbine exhaustthen the LP evaporator. these are also spiral finned

tubes welded at the bottom &top header and areconnected to the HP steam drum.

4.SUPER HEATER:-there are two types of superheater in the WHRG these are:-

*LP super heater:- the tube act as super heater for LPsteam. these are the fourth heat transfer surface in thedistribution of gas flow. these consists of finned tubeswelded at the top and bottom headers and havemaximum of two rows per module. These are designedfor the single gas flow on tube side and have a fully

drainable design.

*HP super heater:-these tube act as super heater forthe HP steam. These are the first heater transfersurface in the direction of gas flow. This also consistsof finned tubes with multi pass flow on the tube sideand single flow on gas side.


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Steam drum:-there are two drums placed at the top ofthe WHRSG. These are:-

*LP drum:-this drum store the LP steam producedduring the flow of water in the LP evaporators. it issmaller in size than the hp drum and has a blow cork atits top to avoid blasting at high steam pressures.

*HP Drum:-this drum stores the HP steam producedduring the flow of water through HP super heaters. Italso has the blow cork for safety purposes.

Working of the WHRSG:-

The boiler feed pumps(HPBFP & LPBFP) feed the HP& LP economizers, where the temperature of the waterrises close to the saturation temperature. after flowingthrough the economizer the water is passed to thesteam through feed control system, then water ispassed to the steam drum through feed control system.

then the water is taken to the bottom headers of theevaporators through down pipes ,here the water getsconverted into steam and water. this mixture is carriedto the drum by the risers tubes .In the drum mixture ispassed through centrifugal separators, whereas wateris passed for the recirculation through the down tubes.


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In the super heater the steam gets superheated andtemperature of heat is too high.To control this spray type de-super-heater is provided

between HP economizer 1&2.this steam at the outlet ofthe super-heater is carried to steam turbine throughfeed pipes.

STEAM TURBINE

It is a 156MW,50Hz two cylinder condensing typeturbine. The first cylinder(HP) is single flow type with25 reaction stages and the 2nd cylinder(LP) is doubleflow with 7 reaction stages. It is provided with two mainand two LP stop and control valves.The HP & LP sections have individual turbine rotors,which are connected to each other, and the generatorrotor with rigid couplings. Some of the equipments withthere ratings being employed for the steam turbines

are as follows:-

Basic parts:-


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1.HP TURBINE:- It is a single flow turbine, withhorizontal split casing and double shell. The provisionof the steam inlet temperature and the high pressure to

the admission section is subjected only to lowtemperature and pressure effective at the exhaust ofthe turbine. The HP turbine is pro vided with the twomain stop and control valves to check and regulate theentry of the steam into the three casing

2.LP TURBINE:-It has a three shell design and has adouble flow system for maximum efficiency. The innercasing carries the first row of stationary blades and issupported on the inner outer casing so as to allow forthermal expansion. The middle casing rest on fourgrids, independent of the outer casing. The LP turbineis provided with two LP stop and control valves.

3.BEARINGS:-Ihe HP rotor is supported on thebearings a combined journal bearing close to thecoupling with LP rotor. the LP rotor has a journalbearing at its end. the bearing pedestals are anchoredto the foundation and are fixed in position.


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WORKING OF THE STEAM TURBINE:-

The HP turbine is feeded to the HP section of the

steam turbine. The steam passes through the stopsand control valves of the HP turbine and enters theinner casing. On entering the inner casing the steamexpands, which rotates the blades of the HP turbine,the steam after leaving the HP turbine gets convertedinto LP steam. This LP steam produced at the WHRSGare passed into the inlet of double flow large LP turbine

on entering the steam once again expands to whichthe rotor of the combine effect rotation of large HP andlarge LP rotors the generator rotor is also rotate andthe electricity is produced. The two outlets of the LPturbine are connected to the condenser where the


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water and steam mixture are converted into water forfurther use in the WHRSG.


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(C & I DEPARTMENT)(MAJOR ROLE OF ECE)

AUTOMATION AND CONTROL SYSTEM

AUTOMATION : THE DEFINITION

The word automation is widely used today in relation tovarious types of applications, such as officeautomation, plant or process automation.

This subsection presents the application of a controlsystem for the automation of a process /plant ,such aspower station. In this last application ,the automationactively controls the plant during the three main phasesof operation : plant start-up, power generation in stable

or shut- down.

During plant start-up & shut-down , sequencecontrollers as well as long range modulating controllersin or out of operation every piece of the plant ,at thecorrect time & in coordinated modes, taking modes,taking into account safety as well as overstressing

limits.

During stable generation of power, the modulatingportion of the automation system keeps the actualgenerated power value within the limits of the desiredload demand.


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During major load changes, the automationsystem automatically redefines new set points &

switches ON or OFF process pieces, to automaticallybring the individual processes in an optimallycoordinated way to the new desired load demand. Thisload transfer executed according to pre-programmedadaptively controlled load gradients & in safe way..

AUTOMATION: THE BENEFITS

The main benefit of plant automation are to increaseoverall plants availability and efficiency .the increase ofthese two factors is achieved through a series offeatures summarized as follows:

* Optimization of house load consumption during

plant start up, shut-down and operation, via:

- faster plant start-up through elimination of controlerrors creating delay

- Faster sequence of control actions compared tomanual ones. figures 1 shows the sequence of a

rapid restart using automation for a typical coal-fired station .even a well-trained operator crewwould probably not be able to bring the plant thefull load the same load without considerable risks

- Co-ordination of house load to generate poweroutput.


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Ensure and maintain plant operation, even in caseof disturbances in the control system ,via

-coordinated ON/ OFF and modulating control switchover capability from a sub process to a redundantone.-prevents sub process and process tripping chainreaction following a process component.

Reduce plant / process shutdown time for repairand maintenance as well as repair costs, via:

-protection of individual components againstoverstress (in a stable or a stable plant operation).-bringing process in a safe stage of operation, whereprocess component are protected againstoverstress.

PROCESS STRUCTURE

Analysis of processes in power station and industryadvocates the advisability of dividing complex overallprocess into individual sub-process having distinctlydefined function, this divisor of process in clearlydefined groups termed as FUNCTIONAL GROUPSresulting a hierarchical process structure. While thehierarchical structure is governed in the horizontaldirection by the number of tribes (motorized valves,fans, dampers, pumps, etc) in the words the size of


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the process; in the vertical direction, there is adistinction made between fundamental levels.These being the:-

A. drive levelB. function group levelC. unit level

To the drive level, THE LOWEST LEVEL, belongingthe individual process equipment and associatedelectrical drives.

The function group is a part of the process that fulfillsa particular task. E.g. induced draft control, feedwater control, blooming control, etc.Thus at the time of planning it is necessary toidentifying each function group in a clear manner byassigning it to a particular process activity.Each function group contains a combination of itsassociated individual equipment drive. The drivelevels are sub ordinate to this level.

The above three levels are defined with regards tothe process and not form the control point of view.

CONTROL SYSTEM STUCTURE


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The primary requirement to be fulfilled by any controlsystem architecture is that it be capable of beingorganized and implemented on true process-oriented

lines. In order words, the control system structureshould map on the hierarchy process structure.

BHELS PROCONTROL P ,a microprocessor basedintelligent remote multiplexing system, meets thisrequirements completely.

SYSTEM OVERVEIW

The control and automation system used here is amicro based multiplexing system .this system.Designed on a modular basis, allows to tighten thescope of control hardware to the particular controlstrategy and operating requirements of the process.

Regardless of the type and extent of process tocontrol provides to control provides systemuniformity and integrity for :

Signal conditioning and transmission Modulating control


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.

CONTROL AND MONITORING

MECHANISM

There are basically two types of problems faced in apower plant:

Metallurgical

MechanicalMechanical power related to the turbine that is the

max speed permissible for a turbine is 3000 rpm,so speed should be monitored & maintained atthat level.Metallurgical problem can be view as the max inletTemperature for turbine is 1060 C so temperatureshould be below limit.

Monitoring of all the parameters is necessary forthe safety of both:

Employees

Machines

So the parameters to be monitored are:

Speed

Temperature

Current

Voltage

Pressure


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Eccentricity

Flow of gases

Vaccum pressure

Valves Level

Vibration

PRESSURE MONITORING

Pressure can be monitored by three types of basicmechanism:

Switches Gauges

Transmitter type

For gauges we use bourden tube: The bourden tubesis a non liquid pressure measurement device. It iswidely used in specifications where in expensive staticpressure measurements are needed.

A typical bourdon tube contains a curved tube thatis open to external pressure input on one end & iscoupled mechanically to an indicating needle on theother end, as shown below:


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Transmitter types use transducers (electrical toelectricl normally) .They are used where thecontinuous monitoring is required.

Normally capacitive transducers are used.


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For switches pressure switches are used & they can be

used for digital means of monitoring as switch beingON is referred as high & being OFF is as low.

All the monitored data is converted to either current orvoltage parameter.

The plant standard for current & voltage are as under:

Voltage : 0-10 Volts range

Current : 4-20 miliAmperes

We use 2mA the lower value so as to check fordisturbances & wires breaks.

Accuracy of such systems is very high.ACCURACY : + -0.1%

The whole system used is SCADA based


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We use DDCMIC control for this process.Programmable Logic Circuits (PLCs) are used in theprocessas they are the heart of instrumentation.

BASIC PRESSURE CONTROLMECHANISM


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Hence PLC selection depends upon the criticality ofprocess.

CONTROL VALVES

A valve is a device that regulates the flow ofsubstances (either gases, fluidized solids, slurries, or

by liquid) by opening ,closing, or partially obstructingvarious passageways. Valves re technically pipefittings, but usually are discussed separately.

Valves are used in a variety of applications includingindustrial, military ,commercial, residential,

transportation. Plumbing valves are the most obviousin everyday life, but many more are used.

Some valves are driven by pressure only, they aremainly used for safety purposes in steam engines &domestic heating or cooking appliances. Others areused in a controlled way like in otto cycle enginesdriven by a camshaft, where they play major role inengine cycle control.

Many valves are controlled manually with a handleattached to the valve stem.if the handle is turned a


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quarter of a full turn(90 ) between operating positions,the valve is called a quarter-turn valve. Butterfly valves,ball valves, & plug valves are often quarter turn valves.

Valves can also be controlled by devices calledactuators attached to stem. They can beelectromechanical actuators such as an electric motoror solenoid, pneumatic actuators which are controlledby air pressure, or hydraulic actutors which arecontrolled by the pressure of a liquid such as oil orwater.

So there are basically three types of valves that areused in power industries besides the handle valves.They are:

Pneumatic Valves:- They are air or gascontrolled which is compressed to turn or

move them. Hydraulic Valves:- They utilize oil in place of

air as oil has better compression.

Motorised Valves:- These valves arecontrolled by electric motors


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TEMPERATURE MONITORING

There are basically three methods oftemperature monitoring. They are:-

Electrical method

field system method

Metallic method

ELECTRICAL METHOD OF TEMPERATUREMEASUREMENT

This method includes:

RTD (PT 100, Cu 53) Thermocouple

Resistance Temperature Detectors(RTD)

Resistance of the element varies in proportionally to the

temperature.Constant current is fed and the with the varying temp

voltage in the circuit varies and the same can be convertedinto thermal through curve fitting equations

PT 100 : 100 ohm at 0 C


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Range : -200 to 850 C

Thermocouple

Electrically conducting and thermoelectrically dissimilarmaterial coupled at an interface is called thermocouple. Thelegs are called thermo elements. Seebeck effect

Type: B, E, J, K, N, R, S & T Type K :Ni-Cr Ni Range: -270 - 1350 C

Reference

Junction

Element

Extension

Cable


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FLOW MEASUREMENT

Differential Pressure- Orifice, Venturi,Nozzle

Variable Area Displacement Turbine Flow meters Ultrasonic Coriolis Effect Mass Flow meter


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(MM DEPARTMENT)


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As the name suggests it has the following roles.

Preventive maintenance (At regular intervals as per

OEM directions)

Breakdown maintenance repair

Diagnostic maintenance - online maintenance and

monitoring of equipments (on about 8-10 machines daily)

The maintenance work can be online or offline.

Online maintenance while machine is in operation

Offline maintenance when machine is shut down

One of the very frequent maintenance work is compressor

washing. It takes place twice per week whenever the outputdecreases by 1.5%. It is generally done online. Soap solution

is used to remove deposits on the compressor blades formed

by dust or other impurities. Electrostatic particle separator is

also used.

Besides, this department also manages the inventory of

spares.

THE OPERATION OF GAS POWERSTATION


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the generation of electricity in the Faridabad gas powerstation takes place in two cycles.

These are

1.close cycle2.open cycle

close cycle:-

In this all the equipments installed participate in thegenerating the electricity.in the gas turbine the natural gases are mixed together with

the compressed air. Compressed air is attained by passingthrough the filters attached at the compressor. Thesecompressed air is mixed with the natural gas or liquid napthaand them burnt in the combination chamber. These gases arepassed to the turbine which generates electricity generateselectricity. The electricity is passed to generator transformer.The electricity generated by each gas turbine is 137.758MW.

the waste gases have a very high temperature about 555C.these are used to heat the demineralised water in the wasteheat economy boiler(WHRB).the steam is formed whichpasses through high pressure turbine NPT and some part i.ethe low pressure steam is passed through LPT low pressureturbine (LPT). The electricity generated is 156.07MW. hencethe total energy generated is 432 MW by the whole plant.

Open cycle:-

The station works in open cycle when water is not available inthe plant or have some fault in WHR.B#2.


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The process is same as the closed but in the opened cyclethe CN 1opens these gases pass though the CN1

(EM DEPARTMENT)


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The basic work done by this department is distribution of

power.The power is generated at 6.6kV voltage level toreduce power losses during transmission ,the voltage isincreased upto 220kV using step up transformer viz.generator-1,2 and steam generator.In switchyard there areb 11bays in total & 3 bays namely mainbus-1,main bus-2 & transfer bus through tapings are made.Finally four transmission lines are extended from theswitchyard towards two different substations namely:

PALLA-1 ,PALLA-2 ,SAMAYPUR-1 ,SAMAYPUR-2.

Various protective schemes are employed at each level of thetransmission system having various equipments like:

Relays

Isolators

Current transformers

Circuit breakers

Lightening arresters

Power communication carrier(PCC)have been employed in switchyard.

TRANSFORMERS

A transformer is a static device which transfers a.c.electrical from one circuit to other at the samefrequency but the voltage level is changed. When thevoltage is raised on output side the transformer is


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called as step up transformer wheras the transformerin which the voltage is lowered on the output side iscalled step down transformer.

PRINCIPLE OF WORKING:

The basic principle of working of transformer iselectromagnetic induction law of faraday's i.e.whenever there is a change in magnetic flux an emf isproduced and the e.m.f produced opposes the causethat produce it ( acc. to lenz's law).

MAIN PARTS OF TRANSFORMER:-

1. MAGNETIC CORE:- It is provided to:

I. Hold the primary and secondary windingsII. To provide an easy path for flow of magnetic

flux.2.PRIMARY WINDING:- This winding is connected to

the supply for a step-up transformer, this winding haslow voltage and provided near the core. It is made ofsuper enameled copper wire.

3.SECONDARY WINDING:-this winding isconnected to the load.for a step down transformerthis winding has low voltage and is provided nearthe core.this is done to reduce the thickness ofinsulation required for the winding.4. INSULATION: Insulation is provided between:


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I. Core and windingII. Primary to secondary winding

Paper insulation is commonly provided between core &windings.Oil used in the transformer helps in coolingthe windings and also provides for insulation.

4. TERMINALS AND BUSHINGS:Bushings are provided to provide insulationbetween body of transformer and output/inputterminals. These are made of ceramic materials.

Terminals are used to connect the windings tosupply load. These are made of low resistivityconducting material.

5. OIL TANK:- Tank is used to house atransformer & to provide oil for its cooling.The quantity of heat dissipated by oil ,made to

circulate in the tank depends upon area of thetank.The area of the tank is increased byproviding cooling tubes around the tank.

6. CONSERVATOR TANK:- It is provided at thetop of transformer tank and is partly filled withinsulating oil.Oil gets expanded on heating.Some empty spaces are provided in the tankto take care for rise in level of oil on heating.

7. COOLING TUBES:- Cooling tubes areprovided around the tank to increase the areaof tank in contact with air .These tubes remainfilled with oil circulating through the tank &


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increase the heat dissipation capacity of thetransformer.

projc finalt

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