1. 1
Abstract
Samman sammi
03475070922
The report is about my internship tenure which made me learn the basics of a combined cycle power
plant. There are ten Gas turbines and 10 HRSGs and 5 steam turbines (one steam turbine with every two
gas turbines) thus successfully following energy economy policy. The auxiliary systems with the main
units are extremely efficient at KAPCO.A very passionate management / a highly skilled and disciplined
man power and most importantly their mutual coordination makes KAPCO known all

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Samman sammi
03475070922
Acknowledgement
Thanks to Almighty ALLAH WHO gave me the strength and will to go out in search of knowledge and
WHO is always our greatest well wisher.
I would thank Engr. Mahmood Rahim & Engr. Arif Mahmood who has assisted me throughout my
internship tenure. Besides his engineering skills and knowledge they are thoroughly a well disciplined
personality. I would always remember their ditch efforts to make me and my fellows entangled in
discussions that ultimately proved to be very fruitful .It was a real feast being with him.
I am very obliged to all the personalities who were always there whenever I asked for help. It was really
a very good experience to be at KAPCO.

3. 3
KAPCO: AN INTRODUCTION
Machining: An Introduction
Power Plant Technology
Samman sammi
03475070922
TABLE OF CONTENTS
COMBINED CYCLE POWER PLANT
Introduction
Functional Description
GAS TURBINE & ITS WORKING PRINCIPLE
Main components of gas turbine Working
Principle (BRAYTON CYCLE)
TURBINE WASHING
General Description
Pre washing
Washing
STEAM TURBINE AND ITS WORKING PRINCIPLE
FUELING OF THE PLANT

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Main Components of a Steam Turbine cycle
LUBRICATION SYSTEM

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A Leading Power Generation Company
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03475070922
KAPCO: AN INTRODUCTION
Kot Addu Power Company Limited (KAPCO)
On June 27, 1996, following international competitive bidding by
the Privatization Commission Government of Pakistan (the
"Privatization Commission"), the management of KAPCO was
transferred to National Power (now International Power) of the
United Kingdom, which acting through its subsidiary National
Power (Kot Addu) Limited ("NPKAL"), bought shares
representing a 26% stake in KAPCO. Later, NPKAL bought a
further 10% shareholding in KAPCO increasing its total
shareholding to 36%.
Kot Addu Power Plant (the "Power Plant") was built by the Pakistan Water and Power Development
Authority ("WAPDA") in five phases between 1985 and 1996 at its present location in Kot Addu, District
Muzaffargarh, Punjab. In April 1996, Kot Addu Power Company Limited ("KAPCO") was incorporated as
a public limited company under the Companies Ordinance, 1984 with the objective of acquiring the
Power Plant from WAPDA. The principal activities of KAPCO include the ownership, operation and
maintenance of the Power Plant.
Shareholding Structure:
Following the successful completion of the Offer for Sale by the Privatization Commission (on behalf of
WAPDA) in February 2005, 18% of KAPCO's shareholding is now held by the General Public. On April
18, 2005 KAPCO was formally listed on all three Stock Exchanges of Pakistan.

6. 6
Location
The Power Plant is situated in District Muzaffargarh, Punjab, 90 K.M. north west of Multan on
the left bank of the River Indus at a distance of 16 K.M. from Taunsa Barrage. The area is
surrounded by agricultural land on the north and west side of Kot Addu.
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03475070922
POWER PLANT TECHNOLOGY
Kot Addu Power Company Limited ("KAPCO") was incorporated in 1996 with the purpose to
contribute economical power to the national grid. KAPCO has shown exceptional results in the
area of plant maintenance, availability, quality standards and financial performance. In April
2005 KAPCO was formally listed on all the three Stock Exchanges of Pakistan. KAPCO is
committed to contributing to Pakistan's economy by powering the lives of its people by
continuously improving its performance through efficient systems, capable workforce and good
governance.
The Power Plant is a multi-fuel gas-turbine power plant with the capability of using 3 different
fuels to generate electricity, namely: Natural Gas, Low Sulphur Furnace Oil and High Speed Diesel to
generate electricity. The Power Plant is also the only major plant in Pakistan with the ability to self start
in case of a country wide blackout.
KAPCO is Pakistan's largest Independent Power Producer (IPP) with a name plate capacity of 1600
MW. The Power Plant comprises of 10 multi fuel fired gas turbines and 5 steam turbines installed in 5
phases between 1985 and 1996. These turbines are divided into 3 energy Blocks with each Block
having a combination of gas and steam turbines. The Power Plant's combined cycle technology enables
KAPCO to use the waste heat from the gas turbine exhaust to produce steam in the Heat Recovery
Steam Generator, which in turn is used to run the steam turbines thereby resulting in fuel cost efficiency
and minimum wastage.

7. 7
PLANT GENERAL CHARACTERISTICS
Block-1
GT 1,2 and ST 9,10
Manufacturer Siemens Germany
Capacity of Gas turbine 2*97MW = 194 MW
Capacity of Steam turbine 100 MW with 2 HRSG’s
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8. 8
In a combined cycle power plant (CCPP), or combined cycle gas turbine (CCGT) plant, a gas turbine
generator generates electricity
and the waste heat is used to
make steam to generate additional electricity via a steam turbine; this last step enhances the efficiency of
electricity generation. In a thermal power plant, high-temperature heat as input to the power plant, usually
from burning of fuel, is converted to electricity as one of the outputs and low-temperature heat as another
output. As a rule, in order to achieve high efficiency, the temperature difference between the input and
Samman sammi
03475070922
10
10
5
1600MW
1541MW
1345MW
1360MW
6 x 132 KV
6 x 220 KV
35,667MWh
GAS TURBINES
HRSGs
STEAM TURBINES INSTALLED
CAPACITY MAX. LOAD
GENERATION
LOAD ACC TO IDC TEST (1996) LOAD
ACC TO ADC TEST (2004) NUMBER OF
FEEDERS
MAX GENERATION IN ONE DAY
Combined cycle Power Plant
INTRODUCTION:
A combined cycle is characteristic of a power producing engine or plant that employs more than one
thermodynamic cycle. Heat engines are only able to use a portion of the energy their fuel generates
(usually less than 50%). The remaining heat (e.g. hot exhaust fumes) from combustion is generally
wasted. Combining two or more "cycles"
BRYTON CYCLE
RANKINE CYCLE

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output heat levels should be as high as possible. This is achieved by combining the Rankine (steam) and
Brayton
Working
principle of a
combined
cycle power
plant
Samman sammi
03475070922
An open circuit gas turbine cycle has a compressor, a combustor and a turbine. In this type of cycle, the
input temperature to the turbine (the firing temperature), is relatively high (900 to 1,400 0c). The output
temperature of the flue gas is also high (450 to 650 0c). This is therefore high enough to provide heat for
a second cycle which uses steam as the working fluid; (a Rankine cycle).
In a combined cycle power plant, the heat of the gas turbine's exhaust is used to generate steam by
passing it through a heat recovery steam generator (HR5G) with a live steam temperature between 420
and 580 0c. The condenser of the Rankine cycle is usually cooled by water from a lake, river, sea or
cooling towers. This temperature can be as low as 15 °C.
Combined cycle plants are usually powered by natural gas, although fuel oil, synthesis gas, Furnace Oil,
High speed Diesel or other fuels can be used. The supplementary fuel may be natural gas, fuel oil,

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COMBINE CYCLE GAS TURBINE
GAS TURBINE
A gas turbine, also called a
combustion turbine,
is a rotary engine
that extracts energy
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03475070922
In a thermal power station water is the working medium. High pressure steam requires strong, bulky
components. High temperatures require expensive alloys made from nickel or cobalt,rather than
inexpensive steel. These alloys limit practical steam temperatures to 655 O( while the lower temperature
of a steam plant is fixed by the boiling point of water. With these limits, a steam plant has a fixed upper
efficiency of 35 to 42%.
DIFFERENCE BETWEEN OPEN AND COMBINED CYCLE:

11. 11
from a flow of combustion gas. It has an upstream compressor coupled to a downstream turbine, and a
combustion chamber in-between. (Gas turbine may also refer to just the turbine element.)
Energy is added to the gas stream in the combustor, where air is mixed with fuel and ignited. Combustion
increases the temperature, velocity and volume of the gas flow. This is directed through a nozzle over the
turbine blades spinning the turbine and powering the compressor.
Energy is extracted in the form of shaft power compressed air and thrust in any combination
and used to power generators
.
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MAIN COMPONENTS OF A GAS TURBINE
Intake Air Filters
These provide clean, filtered and dust free air to
the compressor inlet.
Compressor
Air is drawn in and compressed when passing through rows of rotating blades and stationary
vanes. There are total 16 stages in compressor. At the end of the compressor, before reaching the
combustion chamber, the air is compressed to about 10 bar and has been heated to about 310°C by
compression.
Combustor / Combustion Chamber
The combustor or combustion chamber is the heart of the engine; here the combustible mixture of
compressed air and fuel is burnt. The hot gas output temperature becomes 10000C to 1300°C; its volume
becomes more than doubled by the temperature rise where as pressure remains constant.
Compressed air having about 10 bars pressure and 350°C temperature. The pressurized air that
delivered by the compressor flows around the hot gas path and outer casing paths. Cooled air, which
came from compressor, cooled down the inner casing of combustion chamber. Compressed air serves as a
heat exchanger of the combustion chamber.
Both combustion chambers have eight separate burners. These burners may equip gaseous, liquid
or dual fuel operation. The oil burners designed on reverse flow principle without any moving parts. High
temperature combustion is provided with refractory linings on its upper portion. These combustion
chambers are very easy to assemble and disassemble, so they are easy for inspection and they have good
accessibility for all components. In case of gas ,it has two modes of combustion.
•0 DIFFUSION MODE in which burner has a long flame burning.
•1 PREMIX MODE in which burner has a cattle shape flame burning.
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13. 13
Turbine
The turbine section converts the thermal and kinetic energy of the combustion gases into
rotational mechanical energy. Gas turbines like steam turbines have three or four stages of rotating and
stationary blades. However; because gas turbines work with lower initial inlet pressures, they have fewer
stages and less change in blade height from inlet to exhaust. Turbines normally consist of combination of
impulse and reaction types. The gas turbine also differs from the steam turbine in;
•0 the type of blading material used
•1 the lower ratio of blade length to wheel diameter
•2 less number of turbine stages
Flue gases flow to the turbine with a very high velocity v of about 80 mjs (288 km/hr). It means it
has high kinetic energy. The kinetic energy of flue gases is converted to mechanical energy when flue gas
is expanded in the stages of turbine transferring its energy to the turbine rotor.
The volume of flue gases is increased by expansion and thus temperature is decreased and at the exhaust
it is about 500C
The turbine parts which are mechanically stressed are at the same time subject to very high
temperature, so that these parts are designed with special material and cooling paths are provided for
cooling air to flow.
Exhaust diffuser
It diverts the de-energized (but still hot) flue gases into the ambience to complete the cycle. It is
fitted with filter and silencer.
Bearings:
Bearing are used to lift the shaft, to make the vibration of rotor as small as possible and to make
the friction during the movement of the shaft. As shaft is connected with bearing, this shaft is lifted by oil
flowing in the bearing. The main purpose of using oil in these bearings is cooling of bearings which are
heated because of running of the shaft. Friction is also reduced when we use oil in the bearing.
Samman sammi
03475070922

14. 14
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TURBINE WASHING
Why is it necessary?
After every 250 hours, when the GAS turbine is being operated at Low Sulphur Furnace Oil (LSFO) it is
recommended to carry out water wash of turbine blades.Actually there accumulates sulphur on blades
surfaces which is present in the furnace oil.This accumulation of sulphur on blades surface causes a
decrease in their efficiency.Therefore it is required to carry out washing after every 250 hours when
machine being operated at LSFO.
PRE-Washing Procedure:
While the turbine is in full operation the temperature of the burning gases inside turbine is about 1100 to
1150 C and cooling of the turbine blades is always required to have a proper function and for the safety
of blades. To keep them cool blowers are available and a discharge line is also taken out from compressor
to the rotor for the cooling purpose.
The wheel space temperature is the temperature of Blades space of rotor and stator blades.Its about 380
C to 480 C.
•0 Before washing turbine unit is shutdown and transferred to turning gear motor.
•1 The speed of Turning Gear Motor is 110 rpm.
•2 The spead of the rotating rotor gradually slows down from 2900 /3000 rpm and when it reaches
110 rpm its automatically transferred on Turning Gear Motor.
•3 After 6 to 7 hours the wheel space temperature reaches 150 C.
•4 This time limit is usually for summers and for winters this time is comparatively less.
WASHING:
•0 Then Turbine is given Crank start at crank speed of 475 rpm with the help of starting motor.
•1 Then Washing Pump is started simultaneously.
•2 Hot water at a temperature of 80c is used to wash turbine blades

15. 15
1. WASHING IS CARRIED OUT FOR 25 minutes.
2. The Turbine rotor is brought at zero rpm after 25 min washing.
3. During this time the temperature of wheel space is about 80 C. At this temperature Thermal stresses
are avoided and sagging is thus avoided.
4. Then 40 min are given without any operation while rotor remains at zero rpm.
5. Then after 40 mins turbine is given crank speed with the help of starting motor and washing is again
carried out for 25 mins.
6. From now onwards machines are started normally.
7. The whole Turbine washing is to be taken out within 12 hours and machine must be made available
within this time.
Samman sammi
03475070922

16. 16
STEAM TURBINE
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03475070922
.
GENERAL DESCRIPTION:
A Steam turbine is a turbine that works with the help of superheated steam that has no moisture. We need
moisture free steam because of certain reasons. For example the moisture may cause rust and the surface
of blades corrodes. The blades of a turbine are very expensive and there replacement causes wastage of
huge sum of money and time which increase cost of energy production and this renders a huge loss to the
company.
A combined cycle employs gas and steam turbines. Its called a combined cycle because the exhaust gases
obtained by utilizing gas in the gas turbine after its combustion in the combustion chamber. The
temperature of these hot exhaust gases is very high ranging from about 480 to 510 C. Instead of
wasting such a huge amount of energy into the atmosphere this energy of exhaust gases are used in steam
turbine to produce superheated steam to run a steam turbine.
At KAPCO a steam turbine is installed with every two gas turbines. The exhaust gases of each gas
turbine are utilized in HEAT RECOVERY STEAM GENERATOR (HRSG) which is a non-
conventional boiler. A complete description of HRSG is discussed later.
Two HRSG boilers produce superheated steam that runs a steam turbine. The efficiency of combined
cycle is higher than a closed cycle. Its about 35 % to 40 %.whereas the efficiency of a gas turbine is
25 % to 30 %.Although the efficiencies may vary depending upon the designs of particular gas turbines
and steam Turbines. Here these Efficiencies are for SIEMENS gas turbine and steam turbine. SIEMENS
is Turbine manufacturer based in germany.
When a single Gas Turbine is functioning then only one HRSG system works for that gas turbine and
therefore load of steam turbine is halved.

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SCHEMATIC DIAGRAM OF STEAM TURBINE
Samman sammi
03475070922
Main components of a steam Turbine are discussed as below:

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03475070922
Main Components of a Steam Turbine cycle:
•0 Boiler(HRSG)
•1 Turbine
•2 Condenser
•3 Pump
Now they are discussed in detail separately along with their auxiliaries and other components:
1. BOILER (HRSG):
The exhaust gases of a gas turbine are at a high temperature and such hot gases are utilized in Heat
Recovery Steam Generator (HRSG) . The efficiency of HRSG is relatively higher than conventional
boilers i.e. 40% to 45 % whereas the efficiency of conventional boilers is about 35 0/0 and that of
Burners Boiler is 32% to 40 %.
The HRSG has the capacity of about 200 tons of
steam production in it. There are different stages
of a HRSG.There are generally four stages:
1.LP Evaporator
2.HP Economizer
3.HP Evaporator
4.Superheater
1- LP Evaparator:
The LP Evaporator is basically a Heat Exchanger
( parallel flow ) consisting of a bundle of tubes
confined in a large shell or cylinder.

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The hot water coming from hot well passes through these tubes.The hot water at a temperature of about
125 C to 130 C from feed water tank at low pressure than atmospheric pressure flow through these
tubes.The water flows trough these tubes with the help of Low Pressure Pumps at Feed Water Pumps
Building where these pumps pick hot water from feed water tank and make it flow through LP
Evaporator tubes by first bringing it in LP DRUM that is connected with LP Evaparator.LP Drum
maintains low pressure saturated steam in it ..
The LP Evaporator is the top most stage a of vertically designed HRSG.The exhaust gases of a gas
turbine reach LP Evaporator at the last when the temperature of these gases has been utilized in first three
stages. The temperature of these gases at this stage is about 180 C.When these gases passes across the
water containing tubes it goes through a phase change where water is converted into steam with a little
increase in temperature. The Latent heat is added in water due to which it is converted in steam by
maintaining its temperature.
About 1/5th
volume of water in LP Drum is converted into saturated steam and rest of the water keep
flowing in cycle through tubes or LP Evaporator until it is also converted into saturated steam.The level
of LP Drum is maintained at certain level which is controlled through automatic level detectors. These
send electrical signals to Central Control Room where the readings are viewed on computer screen.
Now the low pressure saturated steam produced in LP Evaporator going through LP Drum that is used for
the purpose of Dearation in DEARATOR.
DEARATOR & its Function:
DEARATOR is drum mounted just below Feed Water tank (As shown in the fig). The purpose of
Dearator is to de-air the hot water at a temperature of 125 C to 139 C coming from the HotWel1. A
Dearator has two inlets. One form hot well and the other from LP Drum.The hot water coming from the
Hot Well is showeed in the dearator and low pressure saturated steam is blown through this showered
water. As air becomes lighter by heating therefore by mixing steam with this showered water the
temperature of air available in hot water increases and it rises and finally it is drained out from Dearator
top. The hot water collected at the bottom of Dearator drum is air-free and is then used convert into steam
in HRSG.

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2- HP ECONOMIZER:
High Pressure (HP) Economizer is also a heat exchanger (counter flow) consisting of a bundle of tubes.
High Pressure Feed water Pumps placed in the Feed Water Pumps Building take water from Feed Water
Tank placed below Dearator and make it flow through HP Economizer. High pressure is developed with
the help of High Pressure Feed Pumps. Here at steam turbines 11 & 12 impeller type Centrifugal pumps
are being used for this purpose(Pump has been viewed in detail). High pressure is developed so that
maximum heat can be absorbed in the economizer by water at higher pressure (The boiling point of a
liquid increase with an increase in pressure).
The flue gases exchange heat to hot water in the tubes of HP Economizer and raise its temperature to
about 140 CAt this heat exchanger there is a sensible heat addition where there is an increase in
temperature of water in the tubes instead of phase change (steam). This high temperature water flows
down to HP Drum.
3- HP EVAPORATOR:
High Pressure Evaporator is also another heat exchanger (Parallel Flow) consisting of a bundle of tubes
through which hot water coming from second stage of the HRSG flows at high pressure.
As discussed before that water comes in HP Drum from Economizer. Then this high temperature water
from HP Drum is taken from suction pump and made flown through HP Evaporator where there is Latent
Heat Addition into the water.
The water is converted into high pressure saturated steam. This steam then goes again in HP Drum where
it maintains high pressure in which high pressure steam is present over a certain level of water. This HP
steam whose temperature is about 270 C flows through the last stage of HRSG called superheater whereas
water that has not been converted into steam in the HP Evaporator is brought again into HP Drum by
Reciprocating Pump.
.

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4- SUPERHEATER:
Superheater is another type of heat exchanger (counter flow) consisting of a bundle of thin walled tubes
for the maximum rate of heat exchange. This part of the HRSG is located directly in front of the exhaust
section where flue gases at a temperature ranging from 480 C to 500 C are coming out. Superheater
utilizes the maximum temperature of hot flue gases and there is a sensible heat addition in the saturated
steam coming from HP Drum; thus increasing temperature of steam in the tubes and making saturated
steam superheated and moisture free. The temperature of this superheated steam is about 480 C to 500 C.
This superheated steam at pressure of about 35 Bars then runs the steam turbine
CONDENSER:
GENERAL ARRANGEMENT:
The Condenser consists of a hotwell and a shell of rectangular shape, on which is placed a pyramidal
neck which is connected to the turbine exhaust hood by means of the expansion joint and the rectangular
neck.
The condenser is placed directly on concrete foundations with no flexible suspensions ( or springs) or
counter reaction devices.
Connection between the condenser hotwell and the condensate extraction pumps is provided by means of
pipings. Each of the four tube bundles is fed through an inlet and outlet waterbox which is bolted together
to the tube sheet. The water boxes are specially designed to uniformly distribute the cooling water flow in
all tubes. The four tube Bundles are identical.
The following main circuits are placed in the condenser shell :
Drain issuing from the flash tank
Air and Non-condensable gases extraction device.
Make-up water.
Main Components/Parts:
• Water Boxes
• Bundles
• Tube Bundles
• Air coolers
• Tube sheets
• Exhaust Neck
• Lower Exhaust Neck
• Upper exhaust neck
• Stainless steel expansion joint installation
• Supports and Anchoring.
ho
FUELING OF PLANT

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Samman sammi
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Since the plants at kapco run on combined cycle which utilizes basically two types of fuels i.e. Liquid &
Gaseous.
The liquid fuels are:
• Furnace oil
• High Speed Diesel Oil (HSD)
While Gaseous Fuel is purely the Natural
Gas. Obtaining of the fuel:
Liquid Fuel is obtained from two sources:
i) Pakistan State Oil (PSO)
Pakistan State Oil is the major contractor for providing Low Sulphur Furnace Oil (LSFO) to Kapco.
This FO is untreated and raw form. The oil reaches the plant through two ways:
2. Pipe Line from Mahmood Kot Oil Depot.
3. Oil Tankers
Why LSFO is used at KAPCO?
Low sulphur Furnace Oil is used at Kapco Gas Turbines because these Gas Turbines have been designed
for LSFO.LSFO contains less amount of sulphur the HSFO(High Sulphur Furnace Oil). Higher the
amount of Sulphur in the fuel the more it contaminates the environment and high amount of sulphur
cause various dangerous diseases. That is why KAPCO besides its designed considerations is IMS
certified company which emphasizes on safety, environment protection along with quality production. So
it uses LSFO to render minimum danger to the environment. The Stakes of Gas turbines are at lower
heights because of very less sulphur exhaust as compared to the plants that use HSFO and their stakes are
very high so that higher sulphur quantity coming out of them spread over large area and may not
endanger seriously one concentrated region. Such plants are installed in Muzaffargarh and Lalpir.
One more advantage of using LSFO is that its higher efficiency cause the machine units to run at peak
speed within 4 to 5 minutes while HSFO units get top speed in one day or two because they use
conventional boilers and HSFO.

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TREATMENT OF FURNACE OIL:
Treatment of LSFO is quite necessary before it can be used in the combustion chambers because it may
contain a no. of impurities in the form of water soluble salts ,oil soluble salts and compounds, and
suspended particles. These impurities can cause a considerable damage to combustion chambers, Turbine
blades and other necessary equipment that are very expensive and these impurities thus lower the overall
efficiency and increase the maintenance costs. Generally these impurities are classified in three types:
. Water Soluble ( Na,K and other 2nd
group elements)
. Oil Soluble (Pb, Ni , Co ,V etc)
. Suspended particles and dust particles
Now there are different methods to remove these impurities. We first discuss the method to remove
water soluble impurities as follows:
There are two methods to remove water soluble impurities from raw FO :
•0 Electrostatic Method
•1 Centrifugal Method
There are five FUEL OIL
TREATMENT PLANTS (FOTPs) at
KAPCO for the treatment of Furnace Oil.
FOTPs nos. 1, 2, 3 and 4 are for E no. 5 is
for Centrifugal Method. Kapco is the only
company that has the facility of removing
water soluble impurities through Centrifugal
method. Centrifugal Method is so far the
most efficient method for the purpose.
1) Electrostatic Method
In an electrostatic method basically the salts
are ionized and made to collect at their
respective electrodes. A large drum is used
for this purpose in which there are cathode
and anode.
Untreated FO is mixed with water in the drum at a specific temperature. The water soluble salts get
mixed with water and +ive and -ive ions are formed. For example in case of NaCI two ions are formed
i.e. Na+ & CI- When electrodes are connected to power supply of high voltage, these ions move to their
respective electrode. Thus these salts are thus removed from the electrodes later on.
Now a chemical called DEMULSIFIER is added into the oil+water mixture.The function of Demulsifier
is to make the oil droplets separate from water droplets.It makes water droplets larger in terms of its
diameter due to which its surface area increases and due to gravity water droplets settle down and drained
to effulant water tanks. This water is called EFFULANT WATER. Thus this treated Oil is obtained and
pumped to treated oil tanks.
An FOTP for electrostatic method generally comprises 7 sections:
Storage and supply of treated and untreated Oil
Pump and Heating System
3-stage Electrostatic Treater
Effluent Water & Treating system
Chemical Forwarding & Dosing System
Compressed Air Systems
Heat Transfer Oil plant with sludge combustion and Handling

25. 25
Lubrication Oil System
• The lubricating requirements for the gas turbine are furnished by a common forced-feed
lubrication system. Lubricating fluid is circulated to the three main turbine bearings, generator
bearings, reducing gear, accessory gear, as hydraulic oil in torque converter and also as control,
trip oil, high pressure hydraulic oil & generator seal oil.
• Such a system must supply cool, clean and pressurized oil to bearing. This lub. system includes
the following.
1. Lub. oil reservoir in the accessory base (12,490 liter)
2. Main lub. oil pump (shaft driven from accessory gear).
3. Auxiliary lub. oil pump
4. Emergency lub. oil pump
5. Auxiliary & emergency seal oil pump
6. Lub. oil heat exchangers
7. Lub. oil filters.
8. Pressure relief valve VR1 in main pump discharge header (6.9)
9. Bearing header pressure regulator VPR2-1 (1.7 bars)
10. Mist Eliminator
Lubricating oil Pumps
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03475070922
2) Centrifugal Method:
In centrifugal Method, water is first added in Oil in the same way as before. Water soluble salts get
dissolved in water and are separated from Untreated Oil. This water containing salts is removed from oil
by centrifugal action. The water+Oil mixture is rotated at a very large speed in a large drum. The
centrifugal force pushes the heavier fluid i.e. water containing salts in it towards outer radial direction
and oil gets deposited in the centre and drained to Treated oil tanks .
Storage tanks
There are total no.of 27 tanks to store untreated FO, treated FO,HSD and effluent water. one tank has the
capacity to store 8000cm3 oil. steam heating is carried out in tanks to keep oil temperature 80 c so that it
can be easily flow through pipes
The distribution of oil tanks is as follows
. For untreated oil, 11 tanks
. For treated oil, 11tanks
. For HSD, 5 tanks
.

26. 26
• Main Oil Pump - positive displacement pump mounted on & driven by the accessory gear, rated
2725 lpm & 7 bar.
• Auxiliary Oil Pump - submerged centrifugal pump driven by AC motor (88QA-1), rated 2460 lpm
& 7.5 bar.
o Higher pressure for torque converter during slow roll & start-up. Starts when speed drop
below 14HS (90% rated speed) stop when turbine attains 95% rated speed.
Also when 63QA-1 sense a drop below 4.83 bar.
• Emergency Lub. Oil Pump - submerged centrifugal pump driven by a DC motor (88QE-1).
Rated at 1590 lpm & 1.4 bar. Back-up for AOP when 63QT-2A & 2B below 0.55 bar.
Gas Turbine Maintenance
• Classification Gas Turbine Maintenance ;
1. Standby Inspection
2. Running Inspection
3. Dis-assembly Inspection
Dis-assembly Inspection can be classified into :
1. Combustion Inspection
2. Hot Gas Path Inspection
3. Major Inspection
Generator
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