thermal power station

PRESENTATION ON

IN-PLANT TRAINING

ATKanti bijlee utpadan nigam ltd. (a jv of ntpc & bseb) Kanti, Muzaffarpur, Bihar

By- Hari ohm SinghReg no:- 09bee020

DURATION:06-06-2011 to 02-07-2011

Formerly

• Vaishali power generating company ltd.(VPGCL)• Owned by “Bihar State Electricity Board”

Currently

• Kanti Bijlee Utpadan Nigam Ltd.• A joint venture of NTPC(51-74%) and BSEB(49-

26%)

Features

• It is totally coal fired thermal power station.

Capacity

• There are two units each of 110MW installed capacity.

• Installed capacity= 2*110 MW

History Of Development of Plant

Step-1 coal to steam

Step-2 steam to mechanical power

Step-3power generation , transmission & distribution

Process of generation of Electricity

Working principle- Modified Rankin cycle

Process 1-2

• working fluid is pumped from low to high pressure.

Process 2-3

• 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 vapor expands through a turbine, generating power.

Process 4-1

• The wet vapor then enters a condenser where it is condensed at a constant temperature to become a saturated liquid.

Process 3-3’

• After the vapor has passed through H.P. it is reheated before passing through I.P. turbine.

• this prevents the vapor from condensing during its expansion which can seriously damage the turbine blades, and improves the efficiency of the cycle

The coal is unloaded either manually or with the help of wagon tippler into the hopper to the conveyer belt.Coal is passed through metal detectors in order to remove metals present in coal.

Stones from coal is removed manually in its journey through conveyer belt.

Then the coal is passed through vibrating screen where coal of 5mm is separated from large coals.

Then coal is crushed in crusher and passed through metal detectors to remove iron particles.Coal is then supplied from coal bunker to pulverizing mill. Coal dust comes out of this mill.(KBUNL have ball mills)

Step1:- coal to steam (coal handling plant)

Step1:- coal to steam(coal handling)

At KBUNL water tube boiler is employed for steam generation.

Fuel is burnt in furnace . The pulverized coal is dried by P.A fans and secondary air is provided by F.D fan for pulverized coal combustion in the furnace.

Water from boiler is passed through the down comers to the bottom ring header. From bottom ring header water goes to water walls for heat absorption and conversion in to steam.Bottom of furnace is open to allow ash/clinkers to fall freely in to the bottom ash hopper. And flue gas is used in economiser and reheaters. Then it is discharged with the help of I.D fan in to atmosphere.

Step1:- coal to steam(steam generation) Boiler

General layout of a Thermal power station

Step-2 steam to mechanical power(turbines)

Step-2 steam to mechanical power(turbines)

High pressure turbine• It is of single flow

design with eight stages of blading.

• Each stage has moving and stationary blades.

• Superheated steam(at 1100⁰c) from boiler drum enters in to it.

• Speed-3000rpm

Intermediate pressure turbine• Double flow

design with seven stages of blading on either side.


• Reheated steam(at 535⁰ c) from H.P turbine outlet enters in to it.

• Speed-3000rpm

Low pressure turbine• It is also of double

flow design with 6 stages in front and rear flow paths.


• Stem out of I.P. turbine directly enters in to it.

• Speed-3000rpm

Step-3 power generation, transmission & distribution

Rating Continuous

Active Output 110 MW

Rated Voltage 11000+/-5%V

Rated Current 7220 A

Power Factor 0.8 lagging

Frequency 50 Hz

Excitation System Static type

Field current at rated output

1335 A

Type of cooling system

Hydrogen Cooled

Hydrogen Pressure

2 Ata

No. Of H₂ cooled elements

06

Cooling medium for H₂

Soft water


Generation Mechanical power produced at the shaft of the turbine is used to rotate rotor.

Rotating Magnetic flux produced by rotor cuts stator conductor and from electromagnetic induction, electricity is produced .

rotor runs at 3000 rpm, produces 3-phase voltage at 11kv , and of 50 HZ frequency.

Oil shielded hydrogen is used for the cooling purpose of generator.In case of any fault if production of plants stops then bearing motor rotates rotor shaft of turbine continuously at 65 rpm. This is because if shaft doesn’t rotate then due to load it may bend.


Transmission

KBUNL has a capacity to generate 220 MW of electricity but only one unit is working and another is under R&M process. 90 MW is generated out of 110 MW.

The transmission is done through 3-phase , double circuit system.

With the help of station transformer 11kv is step up to 220 kv and fed to substation.


Relay circuit• A protective device that operate during faulty condition and gives

command to circuit breaker to trip. Mainly the electromagnetic induction relays are used.

Fault locatorBy comparing voltage and current the relay measures the line impedance up to the point of fault and locate the position of fault from the previous knowledge of line impedance.

Switch gear• Switches used in substation for making or

breaking the electrical contacts in convenient way. There are two type of switches air switch and oil switch.

Substation: A-control room It is the brain of any substation. All necessary steps about Transmission , protection, Charging e.t.c are carried out in the control room. Measuring instruments of the control room:-


Substation: A-control roomVoltmeter and ammeter• As the names imply they are used for measuring

voltage and current respectively.

Power meter• Used to measure the power in standard unit of MW or KW.

Crt screen• A computer arrangement in which current information about transmission line is seen.

Battery roomConsists of several batteries and chargers for emergency purpose.


Substation :-B-switch yard It consists of following equipments :-

transformer• The autotransformer used in power station. It has three windings primary, secondary and tertiary. The 220kv voltage is fed as input to primary by step down 132kv fed to KBUNL as input.

circuit breaker(sf6 at KBUNL)• Used for closing or opening an electrical circuit under normal or abnormal conditions. These circuit breakers are equipped with trip coil connected to relay, design to open breaker automatically

tower• We have suspension type tower called as ‘A’ type tower. The peak point angle is 0⁰ to 2⁰. In this type conductor is suspended with an insulator.

• Guard ring Is used to balance the capacitive current in transmission lines.


Substation :-B-switch yard Current transformer• Used to reduce the current level such that it can be measured easily.

Bus isolators• Used to isolate bus bars.

Lightning arrestor• Used to protect the transmission line and connected equipment during lightening .

Wave trapwave trap which changes the frequency 50Hz to 500Hz can be used for communicate between power plants.

Light Up Process

Step-1

• A controlled quantity of crushed coal is fed to each bowl mill (pulveriser) by its respective feeders and primary air is supplied from the primary air fans which drives the coal as it is being pulverized and transports the pulverized coal through the coal piping system to the coal burner.

Step-2

• The pulverized coal and air discharge from the coal burners is directed towards the centre of furnace to form fire ball.

Step-3

• The secondary air heating system supplies secondary air for combustion in the furnace around the pulverized coal burners and through auxiliary air compartments ,directly adjacent to the coal burner compartments.

Step-4

• Above a predictable minimum loading condition, the ignition becomes self-sustaining. Combustion is completed as the gases spiral up in the furnace.

synchronization

Step-1

• The terminal voltage of alternator must be equal to the bus-bar voltage.

Step-2

• The running speed frequency must be equal to the bus-bar frequency.

• ( Ns=120f/P ) => ( f=PN/120 )• Where, f= frequency,P= no. Of poles ,N= speed of

alternator

Step-3

• The phase sequence of the incoming unit must be same as that of the existing bus bar to which the generator is to be synchronized.

thermal power station

Business

Transcript of thermal power station