training report ktps-final
TRANSCRIPT
MAHARANA PRATAP UNIVERSITY OF AGRICULTURE AND
TECHNOLOGY
UDAIPUR, (RAJ) INDIA
A
Practical Training Report
On
KOTA SUPER THERMAL POWER
STATION
TRAINING HELD FROM
(10 June 2009 to 09 July 2009)
GUIDIED BY SUBMITTED BY
Er. Vinod Yadav Kishan Bhushan Sahay
Electrical Department BE 2nd Year (EE)
1
PREFACE
The rise in civilization is closely related to improvements in transportation
and requirement of energy that is not readily available in large quantities but is also readily
transportable. A very peculiar fact about electrical energy is that neither it is directly
available in nature nor it is directly used finally in this form, yet it is so widely produced and
is the most popular high grade energy.
The purpose behind training is to understand the difficult concepts in a better
way with gain of knowledge. Report starts with a brief introduction of KSTPS followed by
Generator, Turbine, switch gear, switch yard etc.
While writing the report and while I was on my training I was wondering that
science is as ever expanding field and the engineers working hard day and night and make the
life a gift for us.
2
ACKNOWLEDGEMENT
It is a matter of great pleasure and privilege for me to present this report of 30
days on the basis of practical knowledge gained by me during practical training
at KOTA SUPER THERMAL POWER STATION (KSTPS),
KOTA (Raj.) during June-July-2009.
I use this opportunity to express gratitude and debtness to Er.
Vinod Yadav sir, Training Incharge (Electrical Engg.), CTAE, UDAIPUR.
I want to express my thanks to Chief engineers of KSTPS to give
their valuable time and kind co-operation, other staff members for their further
co-operation to gain the better knowledge about the Power Plant.
Kishan Bhushan Sahay
2nd YEAR(EE)
Electrical Engg.
3
INDEX
4. INTRODUCTION 5
5. GENERATOR 6
6.TRANSFORMER 10
7. SWITCH YARD 14
8. SWITCH GEAR 16
9. PROTECTION 18
10. CONTROL ROOM 20
11. AUXILIARY SUPPLY 21
12. TURBINE 23
13. BOILER 24
14. WATER TREATMENT PLANT 26
15. COAL HANDLING PLANT 28
16. COOLING TOWER 31
17. BEARING COOLING WATER 32
18. PUMPS 32
19. H2 GENERATING PLANT 33
20. ELECTROSTATIC PRECIPITATOR 34
21. ASH HANDLING PLANT (A.H.P.) 35
22. SOOT BLOWING 35
23. EFFICIENCY 36
24. CONCLUSION 38
4
INTRODUCTION
The “KOTA SUPER THERMAL POWER STATION” is ideally located on
the left bank of Chambal River at the upstream of “KOTA BARRAGE”. Thermal power
station to produce electrical power for supply undertakings K.S.T.P.S. is designed for
ultimate capacity of 1045 MW. First two units of 110MW each, another three units of
210MW each and further the sixth unit of 195MW have been completed.
The state Rajasthan is predominantly rural and agricultural .While Rajasthan
mineral sources are immense, its sources for power generation weren’t commensurable with
its requirements. The large expense of water, stored by the “barrage” provides, as efficient
direct circulation cooling system for the power station thus avoiding installation of cooling
towers. For bringing in coal for power station and machinery and equipment etc. a 15Km
long private siding from the Gurla Railway Station on Delhi-Bombay broad gauge line has
been laid-up to the power station.
INSTALLATION AND COMMISSIONING OF UNITS:-
The units in K.S.T.P.S. are as:
Stage I - (Two units each of 110 MW)
Stage II- (Two units each of 210 MW)
Stage III- (one unit of 210 MW)
Stage IV- (one unit of 195 MW)
ENERGY GENERATED IN KSTPS
Total generation Capacity
= (2 x 210+2 x 210+1 x 210+ 1 x 195)
= 1045MW
Total generated Electricity (in one hour)
= 1045MW x 1=10.45Lakh units
Total generated Electricity (in 24hours)
= 10.45 x 24= 250.8 Lakhs units
Amount of Coal required (per day) in KTPS is
= 0.5 x 250.8 x 100000 Kg.
= 125.4 x 100000Kg.
= 125.4 million Kg.
This amount of coal is supplied by 5 trains of coal
5
GENERATOR
Generator is the main part of thermal power station or any power plant. A
generator is a machine which converts mechanical energy into electrical energy.
The generator has gas cooling construction enclosing the stator winding, core
and hydrogen coolers .The cooling medium hydrogen is contained within the frame and
circulation by fans mounted on either ends of the rotor .The generator is driven by directly
coupled steam turbine at a speed of 3000 rpm.
Provision has been made for circulating the cooling water in order to maintain
a constant temperature of the coolant i.e. H2 as measured at the fan section side which is in
touch with the temperature of the winding, core and other parts as per load.
Each of the 2 units under stage-1 have been provided with BHEL make 3-phase
turbo generator rated 137.5 MVA, 11KV, 0.8 pf, 7220 Amp, 3000 rpm and 50
cycles/sec .The generator has closed loop of hydrogen gas system for cooling of the stator
and rotor at a pressure of 2.0 atm. is filled in a gas tight outer casing of the generator. H2 gas
circulates inside the casing by two single stage rotor mounted fans on either side of the
rotor .The heated H2 is in turn cooled by six surface type water coolers axially mounted inside
the generator casing .The cooling water is supplied to H2 coolers from the BCW over head
tank.
Each generator has terminal led out of its casing and a star point is formed by
sorting the neutral side terminals by a sorting bar. The neutral is grounded by a 1-phase
11000/220V, 37.5 KVA. Neutral grounding transformer, whose secondary coil is laminated
by laminated strip with mechanical ventilating holes, is connected across a 650V, class 0.4
ohm, 50 kW neutral grounding resistors and relays for protection of generator against stator
earth faults and stator in turn faults (rating 1 amp).
The H2 gas inside the generator casing is prevented from leaking in between
the rotor and shields, by a continuous oil film maintained between the rotor and sealing
rings .The shaft sealing system have two independent oil sources associated pumps,
regulators, coolers filters, electrical controls and alarm system. Two independent oil sources
are provided for air side and H2 side sealing rings. The oil circuit of the H2 side of the shaft
seal is closed and the oil is vacuum treated.
6
TURBO GENERATOR SPECIFICATIONS:-
(a) STAGE –I
Make Russian
Manufacturer BHEL
Type T.G.P.
Apparent Output 137.5MVA
Active Output 110 MW
Power factor 0.8 lagging
Rated voltage 11 KV
Rated current 7200 Amp.
Rated speed 3000 rpm
Frequency 50 Hz
Phase connections Double gen. star
No. of generator terminals 6
Max. Output with air cooling 68.75MVA
Excitation voltage 230V
(b) STAGE –II & III
Make KWVC Craftworks, Germany
Manufacturer BHEL
Rated capacity 247 MVA
Rated Output 210 MW
Rated current 9050 Amp.
Rated terminal voltage 15.75 KV
Rated speed 3000 rpm
Power factor 0.8 lagging
Excitation voltage 310V
Phase sequence Double star
Insulation class B
No. of turns per phase/pole 10
Short circuit ratio 0.49
7
(c) STAGE –IV
Make KWVC Craftworks, Germany
Manufacture BHEL
Rated Capacity 247 MVA
Rated Output 210 MW
Rated Current 9050 Amp.
Rated Terminal Voltage 15.75 KV
Rated Speed 3000 Rpm
Power Factor 0.8 Lagging
Excitation Voltage 310 V
Phase Sequence Double Star
Insulation Class B
No. of Turns per Phase/Pole 10
Short Circuit Ratio 0.49
DESCRIPTION OF THE GENERATOR PARTS:-
1. STATOR BODY:-
Armature of a generator formed of laminations having slots on its inner
periphery to accommodate armature conductors and is known as stator .The stator body is a
totally enclosed gas tight fabricated structure suitably internally to rigidity . The function of
stator frame is to contain and support the stator core winding , hydrogen coolers and also path
for distribution of cooling hydrogen through the generator .
2. STATOR CORE:-
The rotating magnetic field flow with the core .In order to reduce the
magnetizing (eddy) current losses in the active portion of the stator core due to rotation of
field structure in between the stator the entire core is built up of thin laminations .The
segments are stamped out from CRGO .The core contain several pockets separated by steel
spaces for radial cooling of the core by hydrogen.
3. STATOR WINDING:-
The stator has 3 phase double layer, short pitched and bar type of winding
having two parallel paths .Each slot accommodates two bars .The lower and upper bars are
displaced from each other by one winding pitch and connected at their ends so as to form coil
groups .Each bar consists of solid as well as hollow conductors with cooling water passing
through the later alternator
8
4. DISTILLATE HEADER:-
Ring type header, made up of copper are provided separately for distillated
inlet and outlet min the stator of turbine side .The headers are support on insulator and
insulated from stator body .At turbine side each individual bar is connected with inlet/outlet
header .The vent pipe connection are at the top of the both inlet and outlet header .The vent
pipes are connected to gas trap desire to measure the extent of hydrogen leakage into water
circuit.
5. TERMINAL BUSHING:-
Three phases and six neutral terminals are brought out from the stator through
bushings which are capable of withstanding high voltage and provided with gas tight
joints .The bushing is assembled and tested for flow, leakage to ensure tightness and
continuous flow of water.
6. END SHIELD:-
To make the stator body air tight the end shield are fitted .Gas tightness is
achieved by putting a rubber sealing cord .The end shields are made3 in two halves
convenience during erection and installation.
7. ROTOR:-
The field structure is the largest & heaviest component of generator and is
called the rotor. The rotor houses the static excitation winding and the exciting current is
supplied to the rotor through the slip rings & brushes. The rotor shaft is a single piece forging
the longitudinal slot for inserting the field winding. The slots are distributed over the
circumference so that two field solid poles are obtained .
8. BEARINGS:-
The generator bearings are of pedestal type with spherical seating. It allows
self alignment and is supported on a separate pedestal on slip ring side. The bearing has a
provision of hydraulic shaft lifting during start up and turning gear operation to eliminate
shaft current. Shaft bearing and its pipes are insulated from earth.
9. BRUSH GEAR:-
The current carrying gear assembly is rigidly fixed on the extent part of the
bearing pedestal on the exciter side. There are two brushes gear stand for (+) ive and (-) ive
supply. The field to stator wdg. Provide the brush gear. The designs of brushes during normal
operation condition have low coefficient of friction and are self lubricating.
9
TRANSFORMER
Transformer is made up of following parts:-
1. Core
2. Winding
3. On load tap changer
4. Tank
5. Bushing
6. Auxiliary equipment
7. Insulating Oil
8. Cooling system
In KSTPS there are various transformers for various purposes. They are:-
1. Generating Transformer
2. Unit auxiliary Transformer
3. Station Transformer
4. Capacitor voltage Transformer
1. GENERATING TRANSFORMER:-
In KSTPS, there is one generating transformer for each unit of it. There rating are different
depend upon capacity of each unit. The generated electricity from main generator is being
feed into transformer, so it is known as generating transformer. It is three phase power
transformer. It is also known as main transformer. There is a provision of movement of
transformer on rail in the power station during erection and for repair and maintenance.
SPECIFICATIONS:-
Unit 1 & 2:-
Manufacture BHEL
No. /unit One
Type of construction Core type
No. of phases 3
Type of connections HV star, LV delta
No. of Taps 9
Rating 125 MVA, 11/240 KV
Type of winding HV Shielded multilayer
Type of cooling ON/OB/OFB
10
On load losses 78KW
Maximum efficiency 99.72
Oil Temp. Rise 40oC
Core lamination material Cargo sheet steel
Core to LV wdg. Insulation Bakelite
HV to LV wdg. Insulation Paper, press board
Vol. of Air for initial 5750 Lt.
Unit 3,4,5 &6:-
Manufacture BHEL
No. /unit One
Rating 250 MVA
Bushing voltage 240KV
Transformer Ratio 15.75/220KV
Type of cooling ON/OF/AF
Rating OF Cooling 250MVA
ON Cooling 125MVA
Percentage impedance 14%
Winding Temp. Rise 50oC
Line Current HV 602.12A/ LV 9175.15A
UNIT AUXILLIARY TRANSFORMER:-
Power required for all units auxiliary are met by UAT, one for each unit and
there are five units, so five UATs are for five units. This transformer normally
needs the power requirement for all units auxiliary when the unit is synchronies
with the grid and has become stable. It works when load is 40% or more.
SPECIFICATIONS:-
Unit 1 & 2:-
Manufacture BHEL
Type Oil filled natural cooled step down xmer
Type of cooling ON/AN
Rating 15 MVA
Rated Primary Voltage 11 KV
Rated Secondary voltage 6.6 KV
11
Phases 3
Rated Current HV-787 A, LV-1237A
Frequency 50 Hz
Impedance ratio 7%
Oil Temp. Rise 40oC
Winding Temp. Rise 50oC
Core & Winding weight 18320 Kg
Weight of Oil 8220 Kg
Oil quantity 9670 liters
Unit 3 & 4:-
Manufacture BHEL
Type Oil filled natural cooled step down Xmer
Type of cooling ON/AN
Turns Ratio 15.75 KV/ 7 KV
Oil Temp. Rise 40oC
Winding Temp. Rise 50oC
Phases 3
Rated Current HV-550.51A, LV-1238.65A
Frequency 50 Hz
Connection symbol Dd
Customer R.S.E.B
2. STATION TRANSFORMER:-
The station transformer is rated for 50 /25/ 25MVA, 220/7/7MVA, Yd1d1
and is provided with an on load tap changer on HV winding. This permits a voltage
variation of up to 10% in 16 equal steps of 1.25% each.
SPECIFICATIONS:-
Manufactured Crompton Greaves Ltd, Bombay
Total no. provided 2
Type of construction Core type with three limbs
Type of cooling ON/AN,ON/AF
Rated output ON/AF 50/25/25 MVA
Rated voltage at no load HV side 220 KV LV side 7KV
frequencycy 50 Hz
12
Oil Temp. Rise 40oC
Winding Temp. Rise 50oC
Type of HV winding Disc
Type of LV winding Helical
INSTRUMENT TRANSFORMER:-
In KSTPS instrument transformer have wide range in application such as
measurement of voltage, current, power & energy power factor, frequency. It is also used for
protection circuit of the power system for operation of over current, under voltage, earth fault
and other type of relays, The instrument transformer can be classified as
(a). Current Transformer
(b). Potential Transformer
(a). Current Transformer:-
Current transformer is used for monitoring the current for the purpose of
measuring and protection. They can be classified as Dead tank & Inverter type. The dead
tank current transformer accommodate the secondary cores inside the tank which is at ground
potential. The insulated primary passes through the porcelains and the tank and the terminals
into the top chamber. The primary used in such type of construction is of ‘U’ type.
(b). Potential Transformer:-
The function of P.T. is to step down the voltage so that it can be measured by
standard measurement. In three phases P.T. there is 3&5 limbs core construction. The P.T.
may be dry or oil field. The P.T. above 66KV is essentially sealed with inert gas cushion
provided in the top chamber to take care of expansion & construction. The transformer is
generally core type and form Y-Y group and having the insulation as oil and paper
4. CAPACITOR VOLTAGE TRANSFORMER:-Each of the four line
feeders provided with three capacitor vol transformer for metering and synchronizing.
SPECIFICATIONS:-
Manufacture W.S. Insulators of India Ltd., Madras
Type CVE 245/1050
Rated voltage Nominal 220KV
Maximum 245KV
No. of phases 1
Rated primary voltage 220/sqrt 3 KV
Rated secondary voltage 110/sqrt 3 KV
13
SWITCH YARD
The 220KV switch yard has conventional two buses arrangement with a bus
coupled breaker. Both the generator transformer and line feeder taking off from switch yard
can be taken to any of the two buses, similarly two station transformer con be fed from any
two buses. Each of these line feeders has been provided with by pass isolators connected
across line isolators and breaker isolators to facilitate the maintenance of line breaker. Each
220KV line has provision of local break up protection. In event of breaker which
corresponding to bus bar differential protection scheme and trips out all the breakers and
connected zone bus bars differential protection scheme for bus I & II. All the breaker of the
connected zone and bus coupler, breaker will trip in event of fault in that zone.
Each of the two bus bars has one P.T. one for each phase connected to it.
Potential Transformer are make in BHEL oil filled, nitrogen sealed have two core rated for
220KV /110KV. One cores each for metering & protection. Each time line feeders has three
nos. Core for each phase capacitor voltage Trans. for metering and protection are multicored
single phase, oil filled, nitrogen sealed and are provided at rate of one per phase. A described
of electrical equipment at 220KV system are as follows: -
1. Circuit Breaker(MOCB & SF6)
2. Isolators
3. Current Transformers(C.T.)
4. Potential Transformers(P.T.)
5. Lighting Arresters
6. Earthing Arresters
7. Capacitor Voltage Transformers(C.V.T.)
CIRCUIT BREAKER:-
A circuit Breaker is a piece of Equipment which can:-
1. Make or break a circuit either manually or by remote control under normal conditions.
2. Break a circuit automatically under fault condition.
MOCB provided for each stage are BHEL made and rated for 245KV,
2500A , 134MVA. Each pole has three interrupters which are oil filled with nitrogen gas at
7.5 Kg/sq. cm. The three pole of MOCB are designed for single phase individual operation of
any pole. Breaker operate can be done only from respective pole operating mechanism by
putting selector switch on local. And now a days SF6 Circuit Breakers are also used.
Interlock Scheme of Circuit Breaker: -
14
1. Generator Breaker
2. Station Transformer Breaker
3. Line Feeder Breaker
4. Bus Coupler Breaker
ISOLATERS:-
It is essentially a knife switch and is designed to open a circuit under no load.
Its main purpose is to isolate one portion of the circuit from the other and is not intended to
be opened while current is flowing in the line. Such switches are generally used on both sides
of circuit breakers in order that repairs and replacement of circuit breakers can be made
without any danger. They should never be opened until the circuit breaker in the same circuit
has been opened and should always be closed before the circuit breaker is closed.
LIGHTENING ARRESTER:-
An electric discharge between cloud and earth, between clouds or between the
charge of the same cloud is known is as Lightening.
A Lightening Arrester or a surge diverter is a protective device which
conducts the high voltage surges on the power system to the ground.
SPECIFICATIONS OF LIGHTENING ARRESTER:-
Type CPC-II
Maximum Voltage 198 KV / unit
Maximum Current 10KA
No. of Units 6
EARTHING ISOLATORS:-
The term ‘Earthing’ means connecting of the non-current carrying parts of the
electrical equipment or the neutral point of the supply system to the general mass of earth in
such a manner that all times an immediate discharge of electrical energy takes place without
danger.
An Earthing isolator is a large value of capacitance. This can be charged up to
line voltage. Earthing isolator is used to discharge the line capacitance and work on it.
15
SWITCH GEAR
The apparatus used for switching, controlling and protecting the electrical
circuits and equipment is known as switchgear.
A switch gear is one which makes or breaks electric circuit. Numerous
problems arise in erection, testing and commissioning of switch gear and various precautions
are to be made in operating and maintenance of switch gear.
Essential Features of Switch Gear:-
1. Complete Reliability
2. Absolutely certain discrimination
3. Quick operation
4. Provision for manual control
5. provision for instruments
The Switch Gears used at KSTPS are indoor types. The main components of indoor
switchgear are given below:-
1. Bus-Bars 2. Isolating Switches
3. Current Transformers 4. Potential Transformers
5. Circuit Breaker 6. Earthing arrangement
7. Relays 8. Inter-Locking arrangements
BUS-BARS:-
Bus bars are defined as the conductors to which several incoming and
outgoing lines are connected. They are essential component of Switchgear. They are made up
of Cu. and Al. The type and designers of Switchgear depends upon rated normal current and
short circuit capacity. The Bus bars are enclosed in bus bar chamber. The bus bar of
neighboring link units is connected by Al links. The incoming and outgoing cables are
provided for metering purposes. The C.T. normally of ring type is fitted on insulated primary.
The insulation is provided by cast resin fittings.
In KTPS there are two types of indoor type switch gear:
1. 6.6 KV or High tension
2. 415 KV or Low tension
16
ISOLATING SWITCHING:-
1. They are capable of-
a. Interrupting the Transformer Magnetizing Current.
b. Interrupting line charging Current.
c. Interrupting load Transformer Switching.
2. The main application is in connection with feed or bank Transformer feeders
& there units make it possible to switch out one Transformer while the other is still on load.
CIRCUIT BREAKER:-
They are capable of breaking the circuit on faults. It is heavy duty equipment
mainly utilized for protection of various circuit and separation of loads.
The Circuit Breaker uses on a relay or by manual signal. The Circuit Breakers
which are used in Switchgear are MOCB type.
EARTHED SWITCHES:-
Earthed switch is connected between line conductor and earth. Normally it is
open when line is disconnected. The Earthing switched is closed so as to discharge the
voltage trapped on line for high voltage and so the capacitor between line and earth is
charged to high voltage. For maintenance work their voltage are discharged to earth by
closing the earth switch.
INTER-LOCKING:-
The following type of inter- locking are provided
1. The Circuit Breaker must be in open position before it is lowered in this
position.
2. The Circuit Breaker can be closed only raising the final plug in position.
3. The Circuit Breaker can be closed before raising plug in position.
4. Inter-locking between isolators, Earthing switches and Circuit Breakers are
provided.
RELAYS:-
A Protective Relay is a device that detects the fault and initiates the operation
of the circuit breaker to isolate the defective element from the rest of the system.
17
PROTECTION
The fault, which may occur in stator winding are-
1. Phase to phase fault.
2. Phase to ground fault.
3. Short circuit between lines.
4. Over heating.
These faults are due to-
1. Over voltage is because of system transients, lightening switching
surges or sudden loss of load.
2. Insulation deterioration due to any matter, moisture, corona discharge, Hardening
of solid and vibration.
It is very necessary to minimize the tripping time during any fault so that the
lamination is not damaged. The repairing being affected by replacing the faulty stator bar.
A delayed clearance may damage the lamination, so fire may be caused and
partial re-insulation of core may be necessary.
GENERATOR PROTECTION:-
The Generator is required to be tripped or isolated on following types of fault:
1. Failure of generating insulation.
2. Failure of prime mover turbine or boiler.
3. Failure of generating auxiliaries such as hydrogen gas system,
seal oil system, cooling system, and cooling water system.
4. Failure of grid.
The tripping command to the GT breaker is given by master trip relay 866, 86GT, and
86GB. To make it feasible the master trip relay is connected to a common bus. All the
protection relays are connected in between the position of 220V.
D.C. PROTECTION AND THIS COMMON BUS:-
Protection device are that detect abnormal condition in electrical circuit by
measuring the electrical quantity which are different under normal and fault condition. The
basic electrical quantities are voltage, current, phase angle and frequency. The relay doesn’t
operate for normal voltage, normal current, normal phase angle and normal frequency.
Different type of protection can be listed as:
1. Current operated protection.
18
2. Different protection.
3. Voltage operated protection.
4. Impedance type protection.
5. Frequency type protection.
1. CURRENT OPERATED PROTECTION:-
a. Generated differential protection.
b. Generative negative sequence protection.
c. Generator output current protection.
d. Generator stator earth fault protection.
e. Generator REF protection.
f. Generator standby earth fault protection.
g. UAT o/c protection.
h. Generator o/c and short circuit protection.
i. L.B.B. protection.
2. DIFFERENTIAL PROTECTION:-
a. Generator overall differential protection.
b. UAT differential protection.
3. VOLTAGE OPERATED PROTECTION:-
a. Generator over voltage protection.
b. Generator stator E/F protection.
c. GT over voltage protection.
d. PT’s voltage supervision protection.
e. Generator inter-turn fault protection.
4. IMPEDANCE TYPE PROTECTION:-
a. Generator back up impedance protection.
b. Generator loss of exact protection.
c. Generator pole slip protection.
5. FREQUENCY TYPE PROTECTION:-
a. Generator under protection Frequency.
19
CONTROL ROOM
Various measurements can be taken at the control room simultaneously. The
second important part of the control room is relay part. Various relays are provided here. I.L.
Kota provides the instruments for control rooms.
CONTROL ROOM PANELS:-
CP-I:-
1. FAN CONTROL DESK: -
a. ID Fan (Induced draft fan, 3 nos.) at full load.
b. FD Fan (Forced draft fan, 2nos.) at full load.
c. PA Fan (Primary air fan, 3 nos.) at full load.
2. PRESSURE CONTROL DESK: -
a. Furnace pressure (5-10mm.)
b. Primary air header pressure (750-800mm.)
CP-II:-
1. FUEL CONTROL DESK:-
a. Coal oil flow.
b. Oil pressure.
c. Temperature of mill (inlet or outlet)
d. Flow of air (54 tones per hour)
CP-III:-
a. Drum level control, flow of steam water
b. Pressure of steam and water.
c. Temperature of steam and water.
CP-IV:-
1. TURBINE DESK:-
a. Pressure control, load mode control.
b. Speed control.
c. Ejector, control valves, stops valves and deviators.
CP-V:-
1. GENERATOR CONTROL PANEL:-
a. Voltage, current, MVAR.
b. Stator, rotor temperature.
c. For stator cooling.
20
AUXILIARY SUPPLY
Electrical supply system is the most important part of the thermal power
station. The failure of even comparatively small equipment could result in the losing of load
or being put out of commission.
SOURCE OF SUPPLY: -
1. URGENT AUXILLARY: -
Those are associated with running of units whose loss would cause an
immediate reduction unit output.
2. SERVICE AUXILLARY: -
These are common auxiliaries associated with one or more units. There loss
would not affect the output of the unit after considerable time of interval.
SELECTION OF SERVICE VOLTAGE: -
The selection of service voltage at which the large number of auxiliaries in a
station to be supplied has to be made at very early stage in the design. Accordingly the rating
of the unit service voltages is selected. These service voltages for different ratings are:
(1)Above 210MW Three service voltage may be required
415V, 6.6KV & 11KV.
(2)Up to 210MW Two auxiliary voltage of 415V & 6.6KV
are required.
ELECTRICAL AUXILLARY SYSTEM: -
The KSTPS auxiliaries are operated at two voltages that are 6.6KV and 415V.
In respect of 6.6KV system, auto change over facility is provided for change over of source
of supply from unit station in the case of unit trip out. The station is having the following
auxiliary system: -
1. Three phase, 6.6KV, 50 HZ. Underground system for motors
rated above 170KW.
2. Three phase, 4-Wire, 415V, 500HZ. Solidly grounded system
for motor rated up to 170KW.
3. Single phase, 240 V, 50 HZ. System for single phase motors,
AC control circuits and space heaters for motors above 37.5
KW and all switch gear /MCC panels.
4. 220V D.C. underground system for use in control and
protection system.
21
3-, 6.6 KV SYSTEM: -
For the running unit, the unit auxiliaries are normally fed from gen’r itself
through 11/7 KV, 15 MVA unit auxiliary transformers, which is, connected to the unit
switchgear viz. USA and USB. Power to station auxiliaries and by unit auxiliary is fed from
220/7 KV, 50 MVA station transformers through two switchgear viz. 55-1A and 55-1B.
415 V SYSTEMS: -
For driving ten 100W motors and other accessories, we need 415V supply. For
this purpose various transformer are used to step down 6.6 KV to 415V at various places. Oil
circuit breaker is provided between 6.6 KV bus and primary winding of transformer.
This system is three phase, 4-wire solidly grounded system is made available
for 1000 KVA, 6.6 KV/ 433V transformer. All 415 circuit breakers are Air Circuit Breaker.
240 V SYSTEMS: -Single - , 240 V, 50 HZ. System is provided for control circuits of
contactors modular of all 415 V switchgear or MCC space heating of various switchgears and
space heating of all motor above 37.5 KW rating. Each of modules with power contactor in
415 V 24 V SYSTEMS: -Single - , 24 V, 50 HZ. Supply is used for winding heating of
motors up to 37.5 KW. This is made available by one or more 1- 415 V/24 V, 4 KVA
transformers. Three transformers are provided with 415 V switchgear/MCB.
220 KV SYSTEMS: -Two 220 KV buses have been provided in switchyard and are inter
connected through a bus coupler. Each of the 2X110 MW generators are connected to this
system through a step up 125 MVA 240/11 KVYDI generator.
220 V A.C. SYSTEMS: -1- 24 V, 50 cycles supply is used for winding heating of
motors up to 37.5 MW. This is made available by 415V/24 V, 4KVA transformer provided
for each 415 V switchgear /MCC. The control circuitry of the motors feeders up to 37.5 KW
ensures that the winding heating supply in switch head off before the main power supply to
motor is switched on.
220 V D.C. SYSTEMS: -
The station 220V D.C. system is used for control, interlocks, and protection
indication and annunciation circuit of various equipments. In addition some critical unit and
station auxiliary also operate on 220 V D.C. e.g. D.C. emergency oil pump for turbine
lubrication D.C. SOP D.C. lightning etc.
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TURBINE
Turbine is an m/c in which a shaft is rotated steadily by the impact of reaction
of steam of working substance upon blades of a wheel. It converts the potential energy or
heat energy of the working substance into mechanical energy. When working substance is
steam it is called ‘Steam Turbine’
In the steam turbine the pressure of the steam is utilized to overcome external
resistance and the dynamic action of the steam is negligibly small.
PRINICIPLE:-
Working of the steam turbine depends wholly upon the dynamic action of steam.
the steam is caused to fall with pressure in a passage of nozzle, due to this fall in pressure, a
whole amount of heat energy is converted into mechanical energy & steam is set moving with
the reactor velocity. The rapidly moving particle of steam enter the moving part of turbine and
here suffers a change in the direction of motion which gives rise to change of momentum and
therefore to a force. This constitutes a driving force to a machine.
The passage of the m/c through the moving part of the turbine commonly
called the blade, may take place in such a manner that the pressure at the outlet sides of the
blade is equal to that of the inlet side. Such a turbine is broadly termed as outlet turbine or
Impulse Turbine.
On the other hand, the pressure of the steam at outlet from the moving blade
may be less than that at type inlet side of the blade. The drop of pressure suffered by the
steam during its flow through the moving blades causes a further generation of kinetic energy
within the blades and adds to the propelling force which is applied to the turbine rotor, such a
turbine is broadly termed as Reaction Turbine.
TURBINE SPECIFICATION: -
Rated output 110 MW
Economic output 95 MW
Rated speed 3000 rpm.
Direction of rotation viewing front pedestal Clockwise
Maximum pressure of steam before the stop valve 145atm.
Maximum temperature of steam before the stop valve 545oC
Maximum pressure of steam before MP Casing 35atm.
Maximum temperature of steam before MP Casing 545oC
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BOILER
A boiler is an enclosed that provides a means for combustion heat to be transfer into water
until it becomes heated water or steam. Its volume increases 1600 times. The process of
heating a liquid until reaches its gaseous states its called evaporation.
The boiler system comprises of
1. feed water system
2. steam system
3. Fuel system
1. Feed Water system:-
It provides water to the boiler and regulate feed according to demand.
2. Steam system:-
It collects and controls the steam produced in the boiler steam are directed
through a piping system to a point of use. Steam pressure is regulated using valves and
checked with pressure gauges.
3. Fuel system:-
Fuel system includes all equipments used to provide fuel to generate the
necessary heat for higher boiler efficiency feed water is preheated by economizer using the
waste heat in the flue gases.
ECONOMIZER:-
The purpose of the economizer is to preheat the boiler feed water before it is
introduced into the steam drum, and to recover some of the heat from the flue gases leaving
the boiler. Economizer is located in the boiler near gas pass below the rear horizontal super
heater. Each section is composed of a number of parallel tube circuits. All tube circuit’s
originate from the inlet header & discharge into the outlet header & economizer header tubes.
SUPER HEATER:-
The super heater is composed of 5 basic stages of sections:
1. Pendant Section
2. Platen Section
3. Rear Horizon Section
4. Steam Cooled Wall
5. Roof Section
1. Pendant Section:-
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It is located directly behind the screen tubes. It absorbs heat by convection.
2. Platen Section:-
It is located directly above the furnace in front of the furnace or arcs. It
absorbs heat mainly by radiation.
3. Rear Horizon Section:-
It is located in the rear vertical gas pass above the economizer. It is the
primary super heater of the convulsive counter flow type.
4. Steam Cooled Wall Section:-
It is from the side front and rear walls and roof of the vertical gas pass.
REHEATER:-
It is composed of two stages or sections the front pendant vertical spaced and
the rear spaced. Rear pendant is located above the furnace arcs between the water cooled
screen tubes and the rear water wall hanger tubes.
AIRPREHEATER:-
The function of an air preheater is similar to that of an economizer. It recovers
some portion of heat of flue (exhaust) gases and transfers the same to the air before it passes
into the furnaces for combination purposes. Air preheater is generally placed after the
economizer, so that the flue first pass through the economizer and then to the air preheater.
Air preheater is of two types, recuperative and regenerative type
TANGENTIAL FIRING SYSTEM:-
In the tangential firing system the furnace itself constitutes the burner. Fuel
and air are introduced to the furnace through four windows assembly located in the furnace
corners. The fuel and air steams from the wind box’s nozzles are directed to a firing circle in
the centre of furnace.
COMPRESSED AIR SYSTEM:-
The following are:
1. Intake air fillers:- In take air filler is used to prevent dust from entering
compressors.
2. Inter stage coders:-Reduce temp of air before it enters the next stage to reduce work
of compression and increase work efficiency. They are normally water Cooled.
3. Air Dryers:-The remaining moisture is removed by using air dryers as air forged
instrument & pneumatic equipments has to be relatively free from any moisture
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WATER TREATMENT PLANT
The principal problem in high pressure boiler is to control corrosion and steam
quality. Internal corrosion cost power station crores of rupees
WATER TREATMENT STAGE:-
River (raw water) → Clarification → Filtration → Demineralization
CLARIFICATION AND FILTERATION OF WATER:-
River water contains different impurities i.e.
Suspended impurities
Biological impurities
Soluble impurities
Colloidal impurities
WORKING:-
The raw water enters through valve and than chemicals is added. Chlorine and
alum are added. Chlorine is added to remove bacteria etc. Alums are added to make the
impurities heavier, once the impurities become heavier than a no. of flocs are formed. By
mixing the alums, heavy impurities are settle down due to gravity and later removed. The
time required for the formation of floc is called retention time which is generally 3 hours but
this can’t be achieved as it require large tank.
In order to cope up the limitation CLARRIFOCCULATION TANK is used.
This flocculation tank is consist of
1. Clarification zone
2. flocculation zone
After the addition of chemical the basic requirement arises is of mixing. Thus
flash mixers are used. Normally the chemicals mix naturally but when the raw water contains
much impurity than agitators are used to mix them.
Clarrifocculation tank has a central pillar which has four windows at 90
degree. The outer circle is half of windows so that level of water is arise then it flows down
through these windows into overflow channel. After mixing from flash mixer, the water
passes on to central pillar and follows the path as shown in fig. i.e. it moves to max. floc area
and comes out from window at 3.5 m height. The downward flow is through perforated wall
which sinks the raw water. Due to the long path a retention time of 4 hour is easily available.
The capacity of water in this plant is 1000*1000 lt./hr. In flocculation zone
max. floc is formed and after removing it, the clear water moves into clarifier. Some
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impurities are weightless and do not settle down so they are passed through filter beds. There
are two types of filter beds.
1. Gravity filter bed.
2. Forced filter bed.
In FORCED FILTER BEDS raisins are added to settle down the impurities.
In GRAVITY FILTER BEDS graded gravels are arranged. At bottom gravels of big size are
there and above other gravels are arranged according to size. Above it grit and most of the
above is sand.
The clarified water enters into sump. Sump is fully closed leaving one window
to see the level. Since it is fully closed hence no foreign matter can enter into it.
DEMINERALIZING PLANT
Water is mainly used for cooling purpose of different parts like bearing winding etc. in
KSTPS. For this water should be Demineralized (D.M. water).
In this plant process water is freed from all dissolved salts. Equipments for
demineralization cum softening plant is supplied and erected by M/S WANSON (India) Ltd.
Pune. This plant consists of two streams, each stream with activated carbon filter, weak acid,
carbon exchanger and mixed bed exchanger. The filter water goes to DM water plant through
250 dia header from where a header top off has been taken off to softening plant. Two
filtered water booster pumps are provided on filtered water line for meeting the pressure
requirement in DM plant.
When pressure drop across filter exceeds a prescribed limit from the activated carbon
filter enter works acid carbon unit. The dilation water enter the weak base anion exchanger
unit water then enters degassifier unit where free CO2 is scrubbed out of water by upward
counter flow of low pressure air flow through degassifier lower and degassed water is
pumped to strong base exchanger(anion –exchanger).
Arrangement for designing ammonia solution into dematerialized water after mixed bed unit
has been provided for pH correction before water is taken into the condensate transfer pump
the DM water to unit condenser as make up. The softening plant is a plant designed to
produce 100 cubic m/hr. of softened water per stream. It is using for bearing cooling.
PH VALUE OF WATER:-
This is recommended to feed the water in the boiler at 25 degree centigrade
and pH value is 8.2 to 9.2 up to 28 days and the pressure is 59 Kg \cm2.
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COAL HANDLING PLANT
INTRODUCTION:-
The term coal handling plant means to store and to handle the coal which is
transported by the train and convey to the bunkers with the help of belt conveyers. Through
the bunkers coal is transferred to the coal mill and drifted to the furnace. The coal handling
plant includes wagon tippler, conveyer belt, crusher house, stacker & reclaimer, bunkers &
coal mill.
Coal Supply in KSTPS:-
The coal for KSTPS is received from BHARAT COKING COAL,
DHANBAD & SOUTH EASTERN COAL FIELD LTD. BILASPUR by train.
Technical Data:-
Wagon Tippler:-
Nos. Two
Capacity 12 box/hr
Tippler motor:-
Make Siemens
Type Slip ring induction motor
Output 71 KW
Vibrating feeders:-
Type Electro magnet
Capacity 350 T /hr
Method of operation Pulsating direct current
Belt weightier type Electromagnetic
Magnetic separator type DC operated electromagnet
Metal Detector:-
Type Two channel power unit
Power supply 230 V
Bunker level indicator:-
Nos. 4 per bunker
Type Mechanical
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Crusher:-
Type Drive ring granulator
Capacity 550 T/hr
Feed size to crusher 300 mm
Type of crusher cleaning Water jet cleaning
Motor rating 500 HP
Vibrating screens:-
Type mechanical vibrating screens
Location crusher house
Capacity 675 T/Hr
Stacker type Reversible stacker
Effective stack pile height 9 m
Travel speed 7.5 to 15 m/min
Location crusher house (a) at loading &
discharge point
(b) At vibrating ends
(c) At ring granulator
2. STAGES OF COAL HANDLING PLANT:-
Wagon Tippler:-
The term Wagon Tippler contains two words WAGON & TIPPLER .Wagon
means the compartment of train which is just like a container which is used to carry the coal
from mines to generating stations & the word Tippler means a machine, which is used to
unload the wagon into the hopper. Hopper is just like a vessel which is made of concrete &
it is covered with a thick iron net on its top. Here big size coal pieces are hammered by the
labors to dispose it into the hopper.
Convey of coal to crusher house:-
After unloaded the coal wagon into the concrete hopper, the supply of coal is
control by Apron Feeder and Scrapper. Apron feeder is made of iron .After passing through
the scrapper conveyor the coal is fed into the Roll Crusher where the crushing of coal takes
place. In the roll crusher there are two shafts on which metal hammer are mounted, these two
rollers rotates in opposite direction to each other. When the coal comes in between these two
rollers it gets crushed into small pieces and then convey to the separator through belt
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conveyor. In Pent house there is a belt weightier which is used to weight the belt which carry
the coal and feed into the separator with the help of Flap Gate .
Primary Crusher house:-
Coal crusher house is a part of coal handling plant where the coal is crushed
with the help of a crusher machines .In crusher machine there is pair of two shafts on which
hammer are fixed. Both shafts rotates in opposite direction due to which when coal comes
between the two shafts crushed into the small pieces and conveyed to the bunkers or open
storage (stacker) according to the requirement through the belt conveyor.
Stacker & reclaimer:-
Stacker is a place where the open storage of a coal takes place. Reclaimer
means the unloading of coal from the stacker.
Coal Mill:-
In coal mill, coal is pulverized or crushed properly into the powdered form.
Hot air is mixed with powdered coal to remove the moisture from the coal, which increases
the efficiency of plant. Pulverization is done to increase the surface area of coal. From coal
mill coal is drift to the furnace with the help of air. There are four main equipment of coal
mill, which are as follows:-
Bunkers:-
These are basically used to store crushed coil which comes from crusher
house.
Feeders:-
These are used to control the supply of crushed coal to the mill depending
upon load condition.
Feeder pipe:-
Feeder pipe are used to convey the crushed coal to the Tube mill or Bowl
mill.
Tube mill:-
Tube mill is used to pulverize the crushed coal. In the tube mill there is a
cylinder which continuously rotates with 17 to 20 rpm. Around the cylinder there are steel
balls which are around of 70 tones in weight and 50 mm in diameter. These balls are known
as thicrome grinding media ball. Coal is pulverized when it comes between the stationary
surface of the shell & the steel ball. Then this pulverized coal is drifted to classifier where
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filtration of coal takes place. In unit 3 to 6 Tube mill is used.
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COOLING TOWER
It is used to reject heat into the atmosphere. There are two types of the cooling
tower.
(1) Natural draft
(2) Mechanical draft
Natural draft tower used vary large concrete chimney to introduce air
through the media. They are generally used for water flow rate about 45000 m3 /hour. It is
used in utility power station.
Mechanical draft tower utilize large fans to force or suck air through
circulating water. The water falls downward over fills surface which helps in increase the
contact time between the water and air. This held maximize heat transfer between two media.
Cooling rates depend upon fan diameter and speed. This type of tower much wider used.
Mechanical draft towers are available in a capacity from approximately 10
tones, 2.5 m3/hour flow to several thousands tones and m3/hour. Many towers are constructed
so that they can be grouped to achieve the desired capacity.
Fills may be horizontal. Water falls over successive layers, splash bars
continuously breaking into smaller droplets. Plastic is better than wood splash filling.
Circulating water pump house has pumps for condensing the steam for condenser. Five
pumps are used for condensing unit no. 1 & 2 and after condensing this water are discharged
back into river.
Each pump has capacity of 8275vcubic m/hr. develop the pressure about 1.94
kgf/sq.cm. Three seal water pumps are used sealing CW pumps shaft at pressure 4.5
kg/sq.cm.
Two pumps for unit 1 and 2 with one stand is used for supplying raw water to
clarified chemical dosing is done in between and clarified water is taken through main line.
From main line water passes through filter bed to filter the water. Clarified water is pumped
to 42 m. elevation by two pump of capacity 270 cubic m/hour at the discharge pressure of 6.9
kg/sq.cm. At 42 meter elevation the water is stored in tank and used for cooling the oil
coolers and returned back to river. Oil coolers are situated at ground and are three in no. each
unit.
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BEARING COOLING WATER
Water from river comes in plant heat exchanger, where its temperature cools
down and that goes in AHP to make slurry. There are 480 plates’ exchangers. BCW
requirements of boiler and turbine auxiliaries of both the units is meet from BCW soft water
overhead tank with the capacity of 2000 cubic meter
DEAERATOR
DEAREATION OF FEED WATER:-
In deareation dissolve gases such as oxygen & CO2 are expelled by preheating
the feed water before it enters the boiler. All natural water contains dissolve gases in solution
(i.e. oxygen + CO2) are released when water heated.
CONDENSER
In condenser steam changes into water. The basic requirement is to remove
latent heat from the steam which is removed by another water (clarified water) when it
accepts the latent heat and becomes hot, than it is passed to cooling tower. In cooling tower
the water is cooled and then mix with river water.
PUMPS
The entire green colored instrument is pumps which are 18 in no.
to further pass the water.
1. FILTER WATER TRANSFER PUMP:-
It is soft section consisting two types:-
(a) BEARING COOLING WATER PUMP:-
All the bearing temperature is controlled through oil bath and filter water is
used. Oil is used to cool the supplied water. Here doesn’t used raw water because at the time
of puncture it enters in the machinery part and small impurity may stop the operation.
(b) CONDENSATE WATER PUMP:-
This pump is coupled with blue colored motor. In order to couple it with
motor a little opening is left through which water leaks out when pumped
2. FILTER WATER TRANSFER PUMP:-
This pump transfers water to D.M. plant. These pumps are in D.M. section.
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3. POTABLE WATER PUMP:-These pump pumps clear water for potable
purpose for whole plant.
H2 GENERATING PLANT
Hydrogen gas is used for cooling purpose for rotor of the generator. For cooling
purpose we have to use 99.9% pure hydrogen. To avoid fire so we have to apply Hydrogen
cooling. It is very difficult to generate and store the Hydrogen gas because it is very
explosive. Hydrogen as a coolant has the following advantages over air:
1. More efficiency and less noise.
2. Better Cooling.
3. More life and less maintenance.
4. Less chance of fire hazard.
5. Better rating.
GENERATING PLANT:-
Hydrogen gas is produced by electrolytic dialysis by mixing KOH in D.M. water.
This reaction is done in electrolyser where Anode and Cathode are applied. Anode plate is
used for collecting H2 and Cathode plate is used for collecting O2. For electrolytic dialysis
3000 Ampere current is passed into electrolyser. O2 is released to atmosphere and H2 is sent
to next machinery for further treatment.
COLLECTING PROCESS:-
H2 Gas from electrolyser → Refrigerator for cooling → Separator to separate the
moisture → Compressor → Catalytic purifier → Dryer (Al2O3) → H2 cylinder. In compressor
H2 is treating in three steps where pressure is raised up to 130 Kg/cm2. In dryer Alumina is
used to absorb moisture.
CAPACITY:-
In KSTPS the full day capacity of H2 generating is 40 cylinders per day. But in plant
per day utilization are of 15 cylinders. Per cylinder capacity is 200-250 kg and stored H2 is
99.8% pure.
PRECAUTION:-
H2 is very explosive gas so we have to take precautionary steps in order to avoid any
accident these steps are as follows
1. To avoid any accident plant timing is fixed 9 A.M. to 5 P.M.
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2. In generating plant underground wiring is used and spark proof lamination bulbs are
employed.
3. Siren:-H2 ppm is kept maintain if it has some variation than Siren will start.
4. Special roof is made for H2 plant so if gas is leakage than it will escape out easily.
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ELECTROSTATIC PRECIPITATOR
If suspended particles are not removed from the flue glass, and it is allowed to be released in
environment, then it would cause a serious threat to the environment, so it becomes necessary
to extract suspended particles from the flue glass and for this purpose ESP is widely used.
WORKING PRINCIPLE:-An electrostatic precipitator is defined as a device
which utilizes electrical forces to separate suspended particles. The electrostatic
precipitator consists of two sets of electrodes , one in form of thin wire called
“discharge or emitting electrode” and other set is called “collecting electrode” in there
form of plate .
CONSTRUCTION:-
The main parts of ESP are as follows:-
Casing
Hoppers
Collecting system
Emitting system
Rapping mechanism for collecting system
Rapping mechanism for emitting system
Insulator housing
CASING:- It is designed for horizontal gas flow to provide for heat expansion, the
casing is supported by roller bearing support.
HOPPERS:-They are of pyramidal shape .Angle between hopper corner and Hz is
never less than 55 degree.
COLLECTOR SYSTEM:-The profiled collecting electrode is based on the
concept of dimensioned electrode stability .The upper plates have hooks and lower
edge has a receiving plate.
EMITTING SYSTEM:- The framework is thoroughly braced and forms a rigid
box like structure, the emitted electrode is made of hard stainless steel wires.
RAPPING MECHANISM FOR COLLECTING SYSTEM:-The system
employs fumbling hammer which are mounted on an Hz. Shaft in a staggered
fashion .A uniform rapping effect is provided for all collecting plates in one
row .Rapping frequency is very low to minimize the dust loss. The hammers are
operated by motor, so that they strike the plate at fixed frequency.
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ASH HANDLING PLANT(A.H.P)
The ash handling system is provided for continuous collection of bottom ash from the furnace
hearth and its intermittent removal by hydro ejectors to a common slurry sump .It is also
provided for removal of fly ash to the common slurry sump. Each boiler is provided with ash
precipitator for collecting the fly ash from the flue gases with high efficiency of collection to
minimize the dust mains and to reduce the wear of induced draft fan .The fly ash separated
from flue gases in the ash precipitator is collected in hoppers at the bottom from where it is
mixed with water to form slurry, and disposed off to pumping area by means of hydro ash
pumps .Bottom ash from the boiler furnace is passed through slag crushers and then slurred to
the slurry chamber at the suction of the ash disposal pumps .These are high pressure and low
pressure pumps for this purpose .At a time one pump is working and other two are stand by .
From the ash disposal pump house ash slurry is pumped through pipe lines to
the ash damp area within about 1.5 km away from the disposal pump house .two separate
discharge lines are provided one for each unit but only one line is used .The ash slurry from
the two units is taken in one discharge line through electrically operated valves.
SOOT BLOWING
Soot blowing is the process by which we clean the boiler tubes with the help
of steam .A large number of tubes are present inside the boiler .Slowly the fine ash particles
get collected on the tube surface and form a layer, this layer of ash particles is called soot. It
reduces the thermal conductivity.Mainly three types of soot blowers are used in KSTPS.
1. Water wall
2. Super heater soot blower (S.H.S.B)
3. Airpreheater soot blower (A.P.S.B)
1. WATER WALL:-They are 40 in no. and have travel time of 1.5
minute .Initially these are outside the boiler ,when soot blowing process start ,the
glance of the soot blower enter inside the boiler and then rotate and come outside
again .
2. SUPER HEATER SOOT BLOWER:-They are 28 in no. and travel time 6
minute .It has transverse of 5 m inside the boiler .It enters and come out in rotated
motion ,so it rotates in both the cases .
3. AIR PREHEATER SOOT BLOWER:-
37
There are only 2 A.P.H.S.B and has 55 minute traveling time .It is like a disc ,and
have only rotary motion and takes 55 minute for completing the cycle.
38
EFFICIENCY
In KSTPS we convert potential energy or chemical energy of the fuel into heat
by the process of combustion. The heat is given to the water and it converts its form into
steam. The pressure of steam rotates the turbine, which is now in the form of kinetic energy.
Generator producing electrical energy, which is sand to different localities for utilization,
consumes this kinetic energy.
Enthalpy is defined as the thermodynamic property of a system, is equal to
the sum of the sum of its internal energy and the product of its pressure and volume.
Enthalpy is an ancient Greek word meaning evolution and many eminent
scholars have been attempted to define it. It is a mathematical concept of available energy in
the steam.
Efficiency in the case of electrical generator process can be expressed as the
amount of heat energy librated in the boiler compared with the amount of electrical energy
generated with it.
PLANT EFFICIENCY: -
We will divide whole plant efficiency in four-component efficiency:
(1). Cycle efficiency
(2). Turbo generator efficiency
(3). Boiler efficiency
(4). Auxiliary power efficiency
Overall = Boiler x Turbine x Cycle x Generator
1. CYCLE EFFICIENCY: -
Cycle efficiency being the maximum possible heat energy that could
be obtained from any particular set of steam conditions employed. The operation of heat
reduction of condenser, which is almost 50% of the total available heat, makes ranking cycle
relatively inefficient.
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Cycle = energy available for conversion in work Energy given in boiler as heat
It can be controlled by: -
(a). Condenser vacuum.
(b). Steam conditions of CV and LV
(c). Regenerative feed heating.
2. ALTERNATOR EFFICIENCY: -
The alternator is a efficient machine at about 98 % efficiency. The losses are:
(a). Copper and iron loss
(b). Wind age losses
Operationally the plant is governed by the grid requirements. For voltage we
use the set out from generator transformer.
3. BOILER EFFICIENCY: -
It depends upon:
(a). Dry flue gas loss: Increase by excess air in boiler.
(b). Wet flue gas loss: Moisture in coal.
(c). Moisture in combustion loss: Hydrogen loss.
(d). Radiator and in accounted loss.
4. TURBINE EFFICIENCY: -
It means the efficiency of steam turbine in converting the heat energy made
available in the cycle into actual mechanical work.
Turbine losses falls into one or two groups either losses external to the turbine
or losses directly related to the expansion of the steam in the cylinder.
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CONCLUSION
The first phase of Practical Training has proved to be quite fruitful.
It provides an opportunity for encounter with such huge machines like wagon tippler,
110MW & 210MW Turbines and Generators.
The architecture of the power plant, the way various units are linked and the
way working of whole plant is controlled make the student realize that engineering is not just
learning the structure description and working of various machine but the great part is of
planning proper management.
It also provides an opportunity to lean low technology used at proper place
and time can cave a lot of labor e.g. Wagon tippler (CHP).
But there are few factors that require special mention. Training is not carried
to its true spirit. It is recommended that there should be some project specially meant for
students where presence of authority should be ensured. There should be strict monitoring of
the performance of students and system of grading be improved on basis of work done.
However training has proved to be quite fruitful. It has allowed an opportunity
to get an exposure of the practical implementation to theoretical fundamentals.
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