WORKING OF G.N.D.T.P

Since G.N.D.T.P. units are primarily coal fired units so each boiler is provided with

closed milling circuits to pulverize the raw coal which is

received from coal conveying system after coal crushes

before it is fired in the furnace. The necessity of pulverizing the coal is to be ensuring its

maximum possible combustion in the furnace

COAL MILL

COAL HANDLING PLANT

The coal handling plant at G.N.D.T.P. has been supplied and erected by M/s Elecon Engineering Company Limited, Vallabh Vidya Nagar, Gugarat. Coal is transported from the coal mines to the plant site by Railways. Generally, the raw coal comes by railway wagons of either eight wheels weighing about 75 to 80 tones each or four wheels weighing about 35 to 40 tones each.

COAL HANDLING PLANT

UNLOADING OF COAL:-In order to unload coal from the

wagons, two Roadside Tipplers of Elecon make are provided. Each is capable of unloading 12 open type of wagons per hour. Normally one tippler will be in operation while the other will be standby. The loaded wagons are brought to the tippler side by the loco shunters. Then with the help of inhaul beetle one wagon is brought on the tippler table. The wagon is then tilted upside down and emptied in the hopper down below.

UNLOADING OF COAL

CRUSHER HOUSE:-The crusher house accommodates the discharge

ends of the conveyor 4A, 4B receiving ends of conveyor 5A, 5B and conveyor 7A and 7B, two crushers, vibrating feeders and necessary chute work. There are two crushers each driven by 700H.P.

RAW COAL CHAIN FEEDER:-The raw coal chain feeder transports

coal from raw coal bunker to the inlet chute leading to the pulverized/coal mills. There is a double link chain of high tensile strength steel, which moves on wheels and sweeps the raw coal falling over the top of the raw coal chute of the mill. The height of the coal bed in the chain feeder can be adjusted manually by means of lever operated damper. The maximum and minimum heights of the coal bed are 200mm and 120mm respectively.

RAW COAL CHAIN FEEDER:-

RAW COAL BUNKER:-Each of three raw coal bunkers is

fabricated from the sheet metal and is well stiffened all around. The storage capacity of each raw coal bunker is about 500 tones

MILLING CIRCUIT

The crushers crush the coal upto the dia of 20 mm. This coal comes to the raw coal bunker through conveyer belts. This coal is fed into the ball mill through chain feeder, operated by motor. In drum the steel balls are used to make it pulverized. At one end coal enters the mill and from the other end pulverized coal is sucked by vapour fan. The pulverized coal is used for burning in the furnace. On its way the p.c. (pulverized coal) bunker, it goes from classifier and cyclone separator function of classifier is to use the coal for burning coal which could not pass the classifier, is collected on the gravity damper. When the weight of this coal is enough, gravity damper is opened because of the

TURBINE SECTION  The turbine is the prime mover for the generator in the

power plant Different types of steam turbines used in thermal power plants, but the ones. Which are used at G.N.D.T. P. are categorized as follows

S.No. Type of Turbine Turbine at G.N.D.T.P.

1. Horizontal/vertical Horizontal2. Single/multi cylinder Multi

cylinder3. Condensing/non condensing condensing4. Reheat/ non-reheat Reheat5. Regenerative/non regenerative

Regenerative6. With by pas/without by pass

BASIC WORKING OF TURBINEfirst of all the turbine is run on gear motor

with the help of exciter. At that time steam is kept on reticulating with the help of by pass valve. When the pressure of steam is increased to on optimum level and turbine acquires a particular rpm then steam is introduced in the H.P. (high-pressure) cylinder first. The temperature of steam at entrance is 540C and pressure is about 139 Kg/cm2. After doing its work on the H.P. Turbine, the steam is taken out for reheating rated temperature of steam at reheater inlet is 360C.

TURBINE SECTION

WATER TREATMENT PLANT The basic requirement of Water

Treatment in the thermal power station is to provide suitable water for the boiler i.e. the water, which is free from dissolved, suspended, and any other type of impurities. If the water is taken as such without any treatment then this will result in scale and sludge formation, caustic embrittlement and corrosion in the boiler and the pipes.

WATER TREATMENT PLANT

PRABHJOT SINGHRoll No. 11203209

Dept. Of Mechanical Engg.Punjabi University Patiala