SUMMER TRAINING REPORT

Indraprastha power generation company ltd

&
Pragati power corporation ltd

DR. AKHILESH DAS GUPTA INSTITUTE OF TECHNOLOGY &

MANAGEMENT, NEW DELHI – 110053

Submitted by: Submitted to :

FAHEEM AHMAD
420156049
BTECH (EEE)
CERTIFICATE
 ACKNOWLEDGEMENT
It is always a pleasure to remind the fine people in the Pragati Power
Corporation Limited for their sincere guidance I received to uphold my
practical as well as theoretical skills in engineering.
This project involved the collection and analysis of information from a wide
variety of sources and the efforts of many people beyond me. Thus it would
not have been possible to achieve the results reported in this document
without their help, support and encouragement.
I will like to express my gratitude to the following people for their help in the
work leading to this report:
 Supervisors & SSE: for their useful comments on the subject matter
and for the knowledge I gained by sharing ideas with them.
 And teachers from my department like HOD sir and DR. TRINA SOM
etc .
Finally, I apologize all other unnamed who helped me in various ways to have a
good training and teach us that Knowledge is power and unity is strength.
 INDEX
S. N. TOPIC PAGE NO. REMARK
1 Introduction of Organization 7-10
2 Plant Layout Details 11-12
3 Product/Service Details 13-33
4 Details of Production and 34-37
Maintenance
5 Conclusion of training 38-39
6 Future plans of organization 40-41
 CONTENT
TRAINING INFORMATION………………………… …………………………………1
CERTIFICATE…………………………………………………………………………..……..2
ACKNOWLEDGEMENT……………………………………………………………………3
INDEX…………………………………………………………………………………………….4

CHAPTER-1
Introduction Of Organization……………………………………………………..….7-10
Pragati Power Station………………………………………………………………………7
Rajghat Power Station……………………………………………………………………..8
Gas Turbine Power Station……………………………………………………….……..9
Indraprastha Power Station……………………………………………….…………….10

CHAPTER-2
Plant Layout Details………………………………………………………………….…11-12

CHAPTER -3
Product/service details………………………………………………………………….13-33
Cooling Towers………………………………………………………………………………..13-14
Boiler……………………………………………………………………………………………....15-17
Water Tube Boiler…………………………………………………………………………...18-19
Boiler Operation ……………………………………………………………………………..20-22
Boiler Draught………………………………………………………………………………….23-24
Boiler Steam Drum…………………………………………………………………………..24-26
Heat Recovery System (HRSG)………………………………………………………….26-27
Economiser………………………………………………………………………………………27-28
Turbine…………………………………………………………………………………............28-31
Generator…………………………………………………………………………………………31-33

CHAPTER-4
Details of Production and Maintenance ………………………………………………34-37
Salient Features……………………………………………………………………………………34-35
Emission Control…………………………………………………………………………………..36
Founding………………………………………………………………………………………………37

CHAPTER-5
Conclusion of Training ……………………………….……………………………………38-39
Merits………………………………………………………………………………….............38
Demerits………………………………………………………………………………………....39

CHAPTER-6
Future plans of organisation ……………………………………………………………40-41
New Project of This Plant………………………………………………………………40-41
 CHAPTER-1
INTRODUCTION OF ORGANIZATION

Pragati Power Station:

To bridge the gap between demand and supply and to have reliable supply to
the Capital City, a 330 MW combined cycle Gas Turbine Power Project was set
up on fast track basis. This plant consists of 2 x 104 MW Frame 9-E Gas Turbine
Units commissioned in 2002 – 03 and 1 x 122 MW STG Unit commissioned in
2003 – 04. Gas supply has been tied up with GAIL through HBJ Pipeline. The
station is performing satisfactorily meeting the targets set by DERC and CEA.
Due to paucity of water this plant was designed to operate on treated sewage
water which is being supplied from Sen nursing Home and Delhi Gate Sewage
Treatment plants,

Fig. 1.1 Pragati Power Station

RAJGHAT POWER STATION:

Two Units of 67.5 MW were installed in 1989-90 at Rajghat Power House as

Replacement of old Units and the present generation capacity of this Station is
135 MW.
The Units of Rajghat Power House had inherent problems of high vibration and
axial shift persisting for last several years leading to low PLF and low reliability
of these machines. Even after overhauling through OEM the problem used to
reoccur after the operation of Units for about 5 – 6 months. Another cause of
low PLF and PAF was frequent boiler tube leakages and loss of flame.
During the last overhauling of unit No.2 the problem was analysed and found
that it was due to skewed expansion of the turbine casing caused by jamming
of guide keys. The gradient of turbine sole plate was also down from rear
pedestal towards the front pedestal. The condenser neck was cut and turbine
was re-floated after matching the sole plates, parting plane and vertical joint of
turbine. The unit is now operating at around 85% PLF.
Similar rectification works are taken up in unit no. 1 also in the ongoing
overhauling since 19th April 06 . There after RPH is expected to perform at
around 80% PLF.

Fig. 1.2 Rajghat Power Station

GAS TURBINE POWER STATION:

Six Gas Turbine Units of 30 MW each were commissioned in 1985-86 to meet

the electricity demand in peak hours and were operating on liquid fuel. In 1990
the Gas Turbines were converted to operate on natural gas. Later due to
growing power demand the station was converted into combined cycle gas
turbine Power Station by commissioning 3x34 MW Waste Heat Recovery Units,
in 1995-96. The total capacity of this Station is 282 MW. The gas supply has
been tied up with GAIL through HBJ Pipeline. The APM gas allocation was not
sufficient for maximum generation from the power station. Subsequently with
the availability of Degasified LNG an agreement was made with GAIL in Jan.
2004 for supply of R-LNG so that optimum generation could be achieved. The
performance of the station has improved from 49 % in 2002-03 to 70.76 % in
2005-06.

Fig 1.3 Gas Turbine Power Station

INDRAPRASTHA POWER STATION:

The present available capacity of this Station is 247.5 MW. Since it is a coal-
based station, Deshelled coal having ash contents less than 34% is being
procured from NCL, Bina. New ESPs have been commissioned recently on all
the units at a total cost of Rs.35 crores approx. to restrict the particulate
emission below 50mg/NM3.
All these units are quite old and need major R&M to remain in operating
condition for which certain schemes have been prepared.

Fig 1.4 Indraprastha Power Station

 CHAPTER-2
PLANT LAYOUT DETAILS

PLANT OVERVIEW:

PPCL combine cycle power plant uses both steam and gas to generate power.
These combine cycle plants produced higher energy conversion efficiency than
gas or steam alone plants. In PPCL a gas turbine generator generates electricity
and waste heat is used to make the steam to make additional electricity via
steam turbine, the last step enhances the efficiency of electricity generator.
Typically, combine cycle power plants utilizes heat from the gas turbine to
generate steam. In combine cycle power plant, the heat of the gas turbine
exhaust is used to generate steam by passing it through heat recovery steam
generate (HRSG) with live temperature between 420 degree C and 580-degree
C. In case of gas turbine Brayton cycle is used and Rankine cycle is used in case
of steam turbine.
Electronic mark-5 processor is used in case of both GT-1 and GT-2.
CAPACITY OF GT-1 = 104MW
CAPACITY OF GT-2 = 104MW
CAPACITY OF STG = 122MW
TOTAL CAPACITY = 330MW
 CHAPTER-3
PRODUCT/SERVICE DETAIL

3.1 COOLING TOWERS:

Cooling towers are heat removal devices used to transfer process

waste heat to the atmosphere. Cooling towers may either use the
evaporation of water to remove process heat and cool the working fluid to
near the wet-bulb air temperature or rely solely on air to cool the working fluid
to near the dry-bulb air temperature. Common applications include cooling the
circulating water used in
 Fig 3.1 cooling tower

oil refineries, chemical plants, power stations and building cooling. The
towers vary in size from small roof-top units to very large
hyperboloid structures (as in Image 1) that can be up to 200 meters tall and
100 meters in diameter, or rectangular structures (as in Image 2) that can be
over 40 meters tall and 80 meters long. Smaller towers are normally factory-
built, while larger ones are constructed on site. Total 9 cooling tower are
available in this power plant.

3.2 BOILER:

Steam generator or a boiler is a closed pressure vessel used for generation of

steam under pressure. A boiler is usually made of steel in which the chemical
energy of fuel is converted by combustion in to heat and this heat energy of
products of combustion is transferred to water so as to produce steam. When
steam is used in power generation, it is generated at high pressure and in large
quantities due to high efficiency requirements. The design of such boiler is
quite intricate and it depends upon the type of fuel used and its capacity. In a
boiler, the working fluid i.e. water receives heat due to combustion of fuel and
is converted into steam at constant pressure. Its efficiency is around 90%. A
boiler is a device for generating steam, which consists of two principal parts:
the furnace, which provides heat, usually by burning a fuel, and the boiler
proper, a device in which the heat changes water into steam. The steam or hot
fluid is then recirculated out of the boiler for use in various processes in
heating.

3.3 WATER TUBE BOILER:

Here in Rajghat power house water tube boiler is used for generating the
steam. In these boilers water is inside the tubes and hot gases are outside the
tubes. They consist of drums and tubes. The boiler receives the feed water,
which consists of varying proportion of recovered condensed water (return
water) and fresh water, which has been purified in varying degrees (make up
water). The make-up water is usually natural water either in its raw state, or
treated by some process before use. Feed-water composition therefore
depends on the quality of the make-up water and the amount of condensate
returned to the boiler. The steam, which escapes from the boiler, frequently
contains liquid droplets and gases. The water remaining in liquid form at the
bottom of the boiler picks up all the foreign matter from the water that was
converted to steam. The impurities must be blown down

Water tube boiler

3.4 BOILER OPERATION:

The boiler is a rectangular furnace about 50 ft on a side and 130 ft tall. Its walls
are made of a web of high-pressure steel pressure tubes about 2.3 inches in
diameter. Pulverized coal is air blown into the furnace from fuel nozzle at the
four corners and it rapidly burns, forming a large fire ball at the centre. The
thermal radiation of the fire ball heats the water that circulates through the
boiler tubes near the boiler perimeter. The water circulation rate in the boiler
is three to four times the through put and is typically driven by pumps. As the
water in the boiler circulates it absorbs heat and changes into steam at 700˚F
(370˚C) and 3200 psi (22.1 Mpa). It is separated from the water inside a drum
at the top of the furnace. The saturated steam is introduced into superheat
pendant tubes that hang in the hottest part of the combustion gases as they
exit the furnace. Here the steam is superheated to 1000˚F (540˚C) to prepare it
for the turbine. Proper treatment of boiler feed water is an important part of
operating and maintaining a boiler system. As steam is produced, dissolved
solids become concentrated and form deposits inside the boiler. This leads to
poor heat transfer and reduces the efficiency of the boiler.
 Boiler operation

3.5 BOILER STEAM DRUM:

A steam drum is a standard feature of the boiler water pipes. It is a reservoir of

water / steam at the upper end of the tube of water. Drums keep the steam
produced in the water tubes and act as a phase separator for mixed steam /
water. Density difference between hot and cold water helps in the
accumulation of -water/and “hot” saturated steam into the steam drum. Made
of High Carbon Steel with a high tensile strength and work that involves a
temperature of about 390oC and pressures well above 350 psi (2.4MPa).
Separated vapor is pulled out from the top of the drum and distributed to the
process. Further heating of the saturated vapor will make superheated steam
is typically used to drive steam turbines. Saturated vapor is pulled from above
the drum and re-enters the furnace through a superheater. Mixture of steam
and water entering the steam

Boiler steam drum

drum through riser tubes, internal drum consisting of demister separates

water droplets from steam to produce dry steam. Saturated water vapor at the
bottom of the drum flows down through the down comer pipe, usually heated,
for the header and water drums. Accessories include a safety valve, water-level
indicators and level controllers. The feed water is also fed to the boiler drum
through the steam feed pipe extending inside the drum, along the steam drum.
A steam drum is used alone or in company mud-drum/feed water drum
located on the lower level. A boiler with the steam drum and mud / water
drum called a bi-drum boiler and steam drum boilers with only so-called mono-
drum boiler. Construction of bi-drum boiler normally intended for low pressure
boiler-rating while the mono-drum largely designed for high pressure ratings.

3.6 HRSG:

HRSG is an energy recovery heat exchanger that recovers heat from a hot gas
stream. It produces steam that can be used in a process or used to drive a
steam turbine. This combination produces electricity more efficiently than
either the gas turbine or steam turbine alone. The HRSG is also an important
component in cogeneration plants. Cogeneration plants typically have a higher
overall efficiency in comparison to a combined cycle plant. This is due to the
loss of energy associated with the steam turbine The HRSG at PPCL,
Fig 3.6 HRSG at PPCL
 Fig combined cycle of utility HRSG

Evaporator Section:

The most important component would, of course, be the Evaporator Section.

So, an evaporator section may consist of one or more coils. In these coils, the
effluent (water), passing through the tubes is heated to the saturation point
for the pressure it is flowing.

Superheater Section:

The Superheater Section of the HRSG is used to dry the saturated vapour
being separated in the steam drum. In some units it may only be heated to
little above the saturation point where in other units it may be superheated to
a significant temperature for additional energy storage. The Superheater
Section is normally located in the hotter gas stream, in front of the evaporator.

Economizer Section:

The Economizer Section, sometimes called a preheater or preheat coil, is used

to preheat the feed water being introduced to the system to replace the steam
(vapour) being removed from the system via the superheater or steam outlet
and the water loss through blow down. It is normally located in the colder gas
downstream of the evaporator. Since the evaporator inlet and outlet
temperatures are both close to the saturation temperature for the system
pressure, the amount of heat that may be removed from the flue gas is limited
due to the approach to the evaporator, whereas the economizer inlet
temperature is low, allowing the flue gas temperature to be taken lower.. The
steam turbine-driven generators have auxiliary systems enabling them to work
satisfactorily and safely. The steam turbine generator being rotating
equipment generally has a heavy, large diameter shaft. The shaft therefore
requires not only supports but also has to be kept in position while running. To
minimize the frictional resistance to the rotation, the shaft has a number of
bearings. The bearing shells, in which the shaft rotates, are lined with a low
friction material like Babbitt metal. Oil lubrication is provided to further
reduce the friction between shaft and bearing surface and to limit the heat
generated.

3.7 TURBINE:

A windmill is the simplest kind of turbine: a machine designed to capture some

of the energy from a moving fluid (a liquid or a gas) so it can be put to use. As
the wind blows past a windmill's sails, they rotate, removing some of the
wind's kinetic energy (energy of movement) and converting it into mechanical
energy that turns heavy, rotating stones inside the mill. The faster the wind
blows, the more energy it contains; the faster the sails spin, the more energy is
supplied to the mill. Adding more sails to the windmill or changing their design
so they catch the wind better can also help to capture more of the wind's
energy. Although you may not realize it, the wind blows just a bit more slowly
after it's passed by a windmill than before—it's given up some of its energy to
the mill! The key parts of a turbine are a set of blades that catch the moving
fluid, a shaft or axle that rotates as the blades move, and some sort of machine
that's driven by the axle. In a modern wind turbine, there are typically three
propeller-like blades attached to an axle that powers an electricity generator.
In an ancient waterwheel, there are wooden slats that turn as the water flows
under or over them, turning the axle to which, the wheel is attached and
usually powering some kind of milling machine.
There are two types of turbine which is used in this power plant,

1) STEAM TURBINE:
rotate in the currents caused by the hot water vapour. They form part of
a closed water cycle in which water condenses and is then heated until it
evaporates again. Steam turbines therefore do not come into contact
with the fuel deployed and work at temperatures between 500 and 650
°C. Several steam turbines are often arranged in a row so that –
configured for high, medium and low pressure – they are able to
optimally convert the respective steam pressure into rotational
movement.
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, from 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. 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.

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
 Working cycle of steam turbine

Process 1-2: The Working fluid pumped from low to high pressure.
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.
Process 4-1: The wet vapor then enters into a condenser where it is
cooled at a constant pressure and temperature to become a saturated
liquid.
Constructional Features:

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.
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.
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.
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 take up residual thrust from both
directions.

Shaft gland and interstate sealing:

The shaft gland seals the steam inside the cylinders against atmosphere
and the interstage seals restrict leakage at blade tip.
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.
Turbine governing system: The turbine has an electro-hydraulic
governing system backed up with a hydraulic governing system. An
electric system measures and controls speed, output and operate the
control valves hydraulically in conjunction with an electro-hydraulic
converter.
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
1) Differential expansion between the shafting and turbine casing.
2) Bearing pedestal vibrations, measured at all turbine bearings.
3) Relative shaft vibrations measured at all bearings.

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

2) GAS TURBINE:

on the other hand, rotate directly in the hot combustion gases. With
temperatures up to 1500 °C, these gases are much hotter than those in
steam turbines. For this reason, the blades are cooled with air that flows
out of small openings and creates a “protective film” between the
exhaust gases and the blades. Without cooling, the blade material would
quickly wear out A gas turbine, also called a combustion turbine, is a
rotary engine that extracts energy 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's 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 aircraft, trains, ships, generators, and even tanks. Gas turbines
are described thermodynamically by the Brayton cycle, in which air is
compressed Isentropically, combustion occurs at constant pressure, and
expansion over the turbine occurs Isentropically back to the starting
pressure.

The term Brayton cycle has more recently been given to the gas turbine
engine. This also has three components:

1. A gas compressor
2. A burner (or combustion chamber)
3. An expansion turbine

Working cycle of Gas turbine:

There are two type of cycle,

A) IDEAL BRAYTON CYCLE

1) isentropic process - ambient air is drawn into the compressor,
where it is pressurized.
2) isobaric process - the compressed air then runs through a
combustion chamber, where fuel is burned, heating that air— a
constant-pressure process, since the chamber is open to flow in and
out.
3) isentropic process - the heated, pressurized air then gives up its
energy, expanding through a turbine (or series of turbines). Some of
the work extracted by the turbine is used to drive the compressor.
4)isobaric process - heat rejection (in the atmosphere).

Actual Brayton cycle:

1.adiabatic process - compression.
2.isobaric process - heat addition.
3.adiabatic process - expansion.
4.isobaric process - heat rejection.

Gas turbine

GAS TURBINE SPECIFICATIONS

Capacity: 30 MW
Gas pressure: 20 Kg/cm sq
Speed: 5135 rpm
Generator speed: 3000 rpm
Generation at: 11 KV
Exhaust temperature: 560°C
Air flow: 490 Tonne/hr.
STEAM TURBINE SPECIFICATIONS:
Capacity: 34 MW
No. of stages: 50
Steam flow: 125 Tonne/hr.
Inlet temperature: 502°C
Inlet pressure: 40 Kg/cm sq.
Lube oil grade: SP 46
No. of journal bearings: 5
No. of thrust bearing: 1
Coupled Main Oil Pump (MOP) with turbine shaft Exhaust steam
pressure: 3.3 atp
Exhaust steam flow: 2.16 Tonne/hr.
Exhaust pressure: 0.105 Kg/cm sq
Lube oil pressure: 9 Kg/cm sq
Over speed trip: >3300 rpm
Differential expansion: +6 to –4

3.8 GENERATOR:

The class of generator under consideration is steam turbine-driven

generators, commonly called turbo generators. These machines are
generally used in nuclear and fossil fuelled power plants, co-
generation plants, and combustion turbine units. They range from
relatively small machines of a few Megawatts (MW) to very large
generators with ratings up to 1900 MW. The generators particular to
this category are of the two- and four-pole design employing round-
rotors, with rotational operating speeds of 3600 and 1800 rpm in
North America, parts of Japan, and Asia (3000 and 1500 rpm in
Europe, Africa, Australia, Asia, and South America). At PPCL 3000
rpm, 50 Hz generators are used of capacities 122 MW. As the system
load demands more active power from the generator, more steam
(or fuel in a combustion turbine) needs to be admitted to the turbine
to increase power output. Hence more energy is transmitted to the
generator from the turbine, in the form of a torque. This torque is
mechanical in nature, but electromagnetically coupled to the power
system through the generator. The higher the power output, the
higher the torque between turbine and generator. The power output
of the generator generally follows the load demand from the system.
Therefore, the voltages and currents in the generator are continually
changing based on the load demand. The generator design must be
able to cope with large and fast load changes, which show up inside
the machine as changes in mechanical forces and temperatures. The
design must therefore incorporate electrical current-carrying
materials (i.e., copper), magnetic flux-carrying materials (i.e., highly
permeable steels), insulating materials(i.e., organic), structural
members (i.e., steel and organic), and cooling media (i.e., gases and
liquids), all working together under the operating conditions of a
turbo generator. Since the turbo generator is a synchronous
machine, it operates at one very specific speed to produce a constant
system frequency of 50 Hz, depending on the frequency of the grid to
which it is connected. As a synchronous machine, a turbine generator
employs a steady magnetic flux passing radially across an air gap that
exists between the rotor and the stator. (The term “air gap” is
commonly used for air- and gas-cooled machines). For the machines
in this discussion, this means a magnetic flux distribution of two or
four poles on the rotor. This flux pattern rotates with the rotor, as it
spins at its synchronous speed. The rotating magnetic field moves
past a three-phase symmetrically distributed winding installed in the
stator core, generating an alternating voltage in the stator winding.
The voltage waveform created in each of the three phases of the
stator winding is very nearly sinusoidal. The output of the stator
winding is the three-phase power, delivered to the power system at
the voltage generated in the stator winding. In addition to the normal
flux distribution in the main body of the generator, there are stray
fluxes at the extreme ends of the generator that create fringing flux
patterns and induce stray losses in the generator. The stray fluxes
must be accounted for in the overall design. Generators are made up
of two basic members, the stator and the rotor, but the stator and
rotor are each constructed from numerous parts themselves. Rotors
are the high-speed rotating member of the two, and they undergo
severe dynamic mechanical loading as well as the electromagnetic
and thermal loads. The most critical component in the generator is
the retaining rings, mounted on the rotor. These components are
very carefully designed for high stress operation. The stator is
stationary, as the term suggests, but it also sees significant dynamic
forces in terms of vibration and torsional loads, as well as the
electromagnetic, thermal, and high-voltage loading. The most critical
component of the stator is arguably the stator winding because it is a
very high cost item and it must be designed to handle all of the harsh
effects described above. Most stator problems occur with the
winding.

Generator coil

a) STATOR:
The stator winding is made up of insulated copper conductor bars
that are distributed around the inside diameter of the stator core,
commonly called the stator bore, in equally spaced slots in the core
to ensure symmetrical flux linkage with the field produced by the
rotor. Each slot contains two conductor bars, one on top of the other.
These are generally referred to as top and bottom bars. Top bars are
the ones the slot opening (just under the wedge) and the bottom
bars are the ones at the slot bottom. The core area between slots is
generally called a core tooth.
b) ROTOR:
The rotor winding is installed in the slots machined in the forging
main body and is distributed symmetrically around the rotor
between the poles. The winding itself is made up of many turns of
copper to form the entire series connected winding. All of the turns
associated with a single slot are generally called a coil. The coils are
wound into the windings lots in the forging, concentrically in
corresponding positions on opposite sides of a pole. The series
connection essentially creates a single multi-turn coil overall, that
develops the total ampere turns of the rotor (which is the total
current flowing in the rotor winding times the total number of turns).
There are numerous copper-winding designs employed in generator
rotors, but all rotor windings function basically in the same way. They
are configured differently for different methods of heat removal
during operation.

c) BEARINGS

All turbo generators require bearings to rotate freely with minimal

friction and vibration. The main rotor body must be supported by a
bearing at each end of the generator for this purpose. In some cases
where the rotor shaft is very long at the excitation end of the
machine to accommodate the slip/collector rings, a “steady” bearing
is installed outboard of the slip-collector rings. This ensures that the
excitation end of the rotor shaft does not create a wobble that
transmits through the shaft and stimulates excessive vibration in the
overall generator rotor or the turbo generator line. There are
generally two common types of bearings employed in large
generators, journal” and “tilting pad” bearings. Journal bearings are
the most common. Both require lubricating and jacking oil systems.
Jacking oil pumps and Lube oil pumps are used for this purpose.
 CHAPTER-4
DETAILS OF PRODUCTION AND MAINTENANCE

Switch yard

To bridge the gap between demand and supply and to have reliable
supply to the Capital City, a 330 MW combined cycle Gas Turbine
Power Project was set up on fast track basis. This plant consists of 2 x
104 MW Frame 9-E Gas Turbine Units commissioned in 2002 – 03 and
1 x 122 MW STG Unit commissioned in 2003 – 04. Gas supply has
been tied up with GAIL through HBJ Pipeline. The station is
performing satisfactorily meeting the targets set by DERC and CEA.
Salient Features:
Due to paucity of water this plant was designed to operate on
treated sewage water which is being supplied from Sen Nursing
Home & Delhi Gate STPs.
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 Combustors.
With the commissioning of Pragati Power Station, total capacity of
IPGCL & PPCL is 994.5MW and all our efforts are made to maximize
the generation.
Brief history:

A contract was signed with M/s BHEL for installation of 330MW gas-
based power plant in the vicinity of 220V, I.P. Extension, Switchyard
on 05.05.2003. The station is comprised of 2x104MW gas turbines of
GT Frame-9E and 1x122MW steam turbine. The Waste Heat
emanating from gas turbines is being utilized to generate 122MW
power through steam turbine. The hot gases of 560o centigrade with
a mass flow of approx. 14000 metric ton per hour is passed through
02 Nos. waste heat recovery boilers of generate steam. The
environmental friendly quality power generation through this station
is pumped to 220kV Sub Station of Delhi Transco Limited and the
entire power is being utilized by citizen of Delhi.

Fuel:
The primary fuel for gas turbine is natural gas being supplied by M/s
GAIL through HBJ pipe line. The gas is received at GAIL Terminal
installed in the vicinity of the power station. M/s GAIL is committed
to supply 1.75 MCMD of gas on daily basis. The caloric value of
natural gas being received for power generation is in the band of
8200-8500 kilocalories. The secondary fuel for gas turbine id
HSD/Naphtha, which is to be used only in case no gas supply is
available. Demineralized water is injected to control NOx. While
machine is operated on Liquid fuel i.e. HSD/Naphtha.
Raw water:

Raw water requirement is met through Sewage treated water being

drawn from Sen Nursing Home and Delhi Gate Sewage Treatment
Plant. The demineralized water requirement for steam generation is
met up through sewage treated water by treating this through RODM
(reverse osmosis de-mineralised) process. The production of cooling
water requirement for condenser and other equipment is also met
through STW after processing through Lime softening system. The
plant effluent is discharged to river Yamuna after naturalizing and
thus the effluent discharge is better than sewage water. In fact
cleaner water is being discharged to Yamuna River, making the
project more eco-friendly.

Emission control:

In order to make control on flue gas emission specifically NOx. & CO2
a special emphasises being given. To control NOx & CO2, State of art,
Dry Low NOx. (DLN) Burners have been installed on gas turbine while
on natural gas. While the machine is to run on HSD/Naphtha water
injection arrangement has been provided to control the NOx. & CO2.
at present the value of NOx. & CO2 is in order on 17-18 PPM and
4.22% respectively on base load while O2 is 15%. The allowable limit
of NOx. approved by DPCC (Delhi Pollution Control Committee) is 35
PPM, however, there is no cap on CO2 emission.

This is the first plant in India with a facility to control NOx. emission
and is an eco-friendly power station.

Also, a thick belt of plantation has been grown on periphery of the

power plant and small slim bs inside the power plant to make it
environment friendly.
Funding:
The total value of installation the power plant is approx. Rs. 1077.30
crore, which is met by drawing loan from Power Finance Corporation
Ltd. and equity of 30% from Delhi Govt.
Load factor:

The plant is now fully stabilized and average plant load factor is 90+
during the month of August and September 2003. All efforts are
made to active higher plant load factor.
 CHAPTER-5
CONCLUSION OF TRAINING

During the training we find out the this power plant capacity is
330MW of electricity with the help of steam and 2 gas turbine in
which gas turbine capacity is 104MW of electricity in each gas turbine
and steam turbine capacity is 122MW of electricity and I find out the
some merits and demerits which is given below:-
Merits
1. Low operation and maintenance cost of this plant
2. Less space is occupied in this plant
3. Less gas storage
4. Cheaper fuels like natural gas
5. This plant less polluted to our environment

Demerits
1. Temperature of combustion chamber is too high, which results in
shorter life time.
2.Gas turbine has low thermal efficiency
3. Has starting problem
4. Efficient only in combined cycle

ACHIEVEMENTS-:
a) Enterprise Resource Planning (ERP)has been implemented in
IPGCL & PPCL and go live achieved in a short span of 8 months in
Oct-09.
b) Following certifications acquired by all the three Power stations
Pragati Rajghat and Indraprastha Gas Turbine;
c) ISO-9001:2000 for Quality Management
d) ISO-14001:2004 for Environment Management.
e) OHSAS-18001:2007 for Occupational Health & Safety
Management
f) Pragati Power Corporation Ltd, has paid dividend to the
government of NCT of Delhi consecutively for the 6th year since
2003-2004
 CHAPTER-6
FUTURE PLANS OF ORGANISATION

NEW PROJECT OF THIS PLANT

a) Pragati-III Power Project at Bawana:
The foundation stone of the project was laid by the Hon’ble Prime
Minister on 25.03.08 and Turn-key order for setting up the project
was placed on BHEL on 30.04.08. Civil works are in progress. The
project is scheduled for commissioning before common wealth
games 2010.

b)Pragati – II Power Project at Bamnauli :

To meet the power demand of Delhi, it is proposed to set up a 750
MW Combined Cycle Gas Turbine Power Project, Pragati Phase-II,
at Bamnauli by Pragati Power Corporation Ltd. Land has been
acquired. EIA and Other Studies, preparation of Feasibility Report
etc. are in progress. Necessary clearances are being arranged and
inputs tied up. As soon as the gas availability is firmed up, action
will be taken to appoint Consultant and select suitable EPC
Contractor for setting up the project. Plant is likely to be
commissioned by 2011-12.

c)Indira Gandhi STPP in Distt. Jhajjar, Haryana:

A 1500 MW coal based Super Thermal Power Project is being
established by Aravali Power Company Pvt. Ltd., a Joint Venture of
NTPC Ltd., IPGCL& HPGCL with equity contribution in the ratio of
50:25:25: resp. The power generated shall be shared equally by
Delhi & Haryana i.e. 750MW shall be available to Delhi from the
year 2010-11.

d)Development of Mara – II Mahan Coal Block in Distt. Singrauli,

MP:
A Coal Block Mara –II Mahan in Distt. Singrauli, Madhya Pradesh
has been allocated jointly to Harayana Power Generation
Corporation Ltd. (HPGCL) and Govt. of NCT of Delhi / IPGCL. To
expedite the activities of coal block development, a Joint Venture
Company of HPCL & IPGCL, named, ‘Yamuna Coal Co. Pvt. Ltd. ‘has
been formed. Necessary prospecting license and permission for
geological / Topographical surveys are expected in 2009-10 which
may facilitate coal mining in 36 to 48 months. Accordingly,
establishment of a pithead-based power station shall be explored
for sharing of power by Delhi and Haryana. This will yield cheaper
power to Delhi.