Summer Training

Submitted By: -Shristi Sahu

Branch: - Mechanical Engineering

Year: -4th year

Suratgarh Thermal Power Station is the first super thermal plant of Rajasthan.

Suratgarh super thermal power station is located 27 km from Suratgarh -15 km from Suratgarh to Biradhwal on NH-15,then 12km in east from NH-15.

Stage I : - Unit 1 and Unit 2 - 2X250 MW

Stage II : - Unit 3 and Unit 4 - 2X250 MW

Stage III : - Unit 5 - 1X250 MW

Stage IV : - Unit 6 - 1X250 MW

Total Power Generation = 1500 MW

Introduction of Thermal power Plant: -

There are basically three cycles going on in a thermal power plant: -

1. Coal Cycle: - The coal cycle is carried on in Coal Handling Plant (CHP). The coal cycle start from CHP and ends in the boiler furnace.

2. Water Cycle: - Water Cycle starts from Hot well and finishes in Boiler Drum.

Condensed Water from Condenser is stored in Hot well.

Water is fed to deaerator.

From deaerator Water Flow to Boiler Feed Pump (BFP) Suction site.

Discharge of BFP flows to Economizer and then to Boiler Drum

CYCLES: -

3. Steam Cycle: - Steam Cycle starts from Boiler Drum and condense in Hot well.

In Boiler Drum, steam is separated from water with the help of steam separator.

Dry steam then flows from Boiler Drum to Super Heater and then flows to High Pressure Turbine (HPT).

Discharged steam from HPT then flows to Re-heater (in boiler) and then to Intermediate Pressure Turbine (IPT) and then to Low Pressure Turbine (LPT) and then to Condenser.

In condenser steam is condensed into water and water is collected in hot well.

The Thermal Power Plant is basically divided into four parts. They are as follow: -

1. Coal Handling Plant (CHP): - Fuel from the storage is fed to the boiler through fuel handling device. The fuel used in S.S.T.P.S. is coal, which on combustion in the boiler produces ash.

2. Ash Handling Plant (AHP):- The ash produced is collected in the boiler and is removed to ash storage tank. Ash produced are of two types: -

(i) wet ash

(ii) dry ash

In S.S.T.P.S both types of ash are utilized in an economical way.

Thermal Power Plant Constituents: -

3. Water Treatment Plant: - In Water Treatment Plant Water is treated so that no impurities are left in the water to make it suitable for the working process of Power Plant.

4. Boiler, Turbine, Generator and Control Unit: - These are the parts where steam is generated and operated. In the Control Unit each and everything is controlled including auxiliary as well as main equipment.

Coal Handling Plant (CHP) :-It can be called the heart of the thermal power plant because it provide the fuel for the combustion in the boiler.

The coal is received from Jharkhand, Madhya Pradesh. Coal is transported here with the help of railway.

The coal handling plant can be divided broadly into three sections:-

i. Wagon Unloading System

ii. Crushing System

iii. Conveying System

Main Components Of Thermal Power Plant:-

Train containing coal Railway yard Wagon Tripler

HopperTransfer PointRotary Breaker

Coal stock pile Bunker Mill Boiler.

Mills :- The coal is fed to the mills from bunker. In the mills, the coal is crushed into powdered form with the help of Pulveriser. The mill used in S.S.T.P.S. is ball tube mills. Pulverized coal is lifted/fed into boiler with the help of air.

Deaerator: - In this chamber air and air bubbles are removed from the water. Also it provides the necessary pressure so that the water can easily reach up to the boiler. And hence the cycle continues.

Boiler :- It is a closed vessel in which water is heated to generate steam. There are different types of boilers.

In S.S.T.P.S. Natural Circulation, Water Tube Boiler are used.

Fire tube boiler: - In this water partially fills the boiler, leaving some space for steam produced. In this type of boiler, heat is transferred in the tubes and as a result water gets heated in the boiler.

Water tube boiler: - In this type of boiler the water flows in the tube. These tubes are mounted on the boundary wall of the boiler or we can say that the boiler wall is made up of these water carrying tubes. The water in the tubes get heats from the coal burning in the boiler furnace.

Super Heater: - A super heater is a device which removes the last trace of moisture from the saturated steam leaving the boiler tubes and also increases its temperature above the saturation temperature.

Re-Heater: - Re-heaters are provided to raise the temperature of the steam from which part of energy has already been extracted from HP turbine. This is done so that the steam remains dry as far as possible through the last stage of the turbine.

Economizer: - The function of an economizer in a steam generating unit is to absorb heat from the flue gases and add this as sensible heat to fed water. It acts like feed water heater.

Boiler Drum: - Boiler Drum is a pressure vessel. In this place water and steam gets separated from each other which are generated in the furnace walls. The steam from boiler drum is again sent to the Super Heater in the furnace so that superheated steam can be received. The steam is superheated so that maximum output can be gained with minimum losses.

Steam Turbine: - Steam turbine is a rotating machine which converts heat energy of steam to mechanical energy.

Super heated steam from boiler High Pressure Turbine

boiler furnace Re-Heater in BoilerIntermediate

Pressure Turbine

Low Pressure Turbine Condenser

High Pressure Turbine (HPT) and Intermediate Pressure Turbine (IPT) are uni flow turbine whereas the LPT is bi flow turbine.

Condenser:- The steam here is condensed with the help of Cooling water (CW) with the help of tubes. Now this water enters hot well and from there it goes to CEP. In the condenser the pressure drops to approximately -0.918 kg/cm2. The pressure in the Condenser is the lowest in comparison to the whole Power Plant Cycle.

Cooling Tower:- Cooling Tower is a heat rejection device which rejects waste heat to the atmosphere through the cooling of a water stream to a lower temperature. The main types of cooling tower are Natural Draft and Induced Draft cooling Towers. The classification is based on the type of air induction in the tower. These are heat removal devices used to transfer process waste heat to the atmosphere.

Fans:- A fan can be defined as a volumetric machine which like pump moves quantities of air or gas from one place to another. In doing this it overcomes resistance to flow by supplying the fluid with the energy necessary for contained motion. The following fans are used in Boiler house:-

1. Primary Air Fan (PA Fan):- Pulverized coal is directly fed from coal mills to the burner at the four corners of the furnace through coal pipes with the help of heated air incoming from PA fan. Secondly this fan also dries the coal.

2. Forced Draft Fan (FD Fan):- The combustion process in the furnace can only take place when it receives a steady flow of air. This air is supplied by FD Fans.

3. Induced Draught Fan (ID Fan): - The Flue gases coming out of the boiler are passed to the ESP and then dust free gases are discharged up by the chimney to the atmosphere by the ID Fans.

Air Preheater: - Air Preheaters are employed to recover the heat from the flue gases leaving the economizer and are used to heat the incoming air for combustion. This raises the temperature of the furnace gases, improves combustion rates and efficiency.

ESP : - In an Electro Static Precipitator (ESP) the dust gases are passed through an intense Electric Field, Which causes ionization of the gases and they change into ion while travelling towards opposite charged electrode, gets deposited as particles and thus dust is electric deposited an electrode creating the field.

Chimney: - The waste air or steam, which can’t be utilised further are now passed out with the help of chimney in the atmosphere at atmospheric temperature.

Ash Handling Plant (AHP): - The ash which is stored in the base of the boiler as a result of residue of heated coal is also utilised in S.S.T.P.S. Earlier this dry ash was mixed with water and wet ash was formed, which was a total waste. But now a days the dry ash is used in cement factories. This ash is also utilized in other methods such as:-

Manufacturing of building materials.

Making of concrete.

Manufacturing of cement.

Road Construction etc

Water Treatment: -

Water from IG Canal De-silting Chamber silt isremoved

Pump HouseRaw Water Reservoir

Fire Fighting System

Ash Handling Plant

Coal Handling Plant

Water Treatment PlantClarified Water Storage Tank

DM Water Plant

Filtration Plant

Circulating Water Pump House

Bearing Cooling Water Plant

Generator: - All those three turbines rotates a shaft in the same direction. This shaft is connected to a generator. This generator produces the electricity required. From this point the electricity produced is sent to the Electrical Switchyard via transformers. Since generator is producing electricity and is working continuously heat is generated in this part also. And hence cooling of generator is also important. In S.S.T.P.S generator is cooled using Hydrogen Gas.

Mechanical Energy Electrical Energy

Cooling :-

Stator Winding- Direct Water Cooling

Rotor Winding- Hydrogen Cooling

Generator

Control Unit: - In Control Room various controls are provided simultaneously various measurement are made. The unit Control Room has a set of parameter panels for indicating and recording parameters of boiler and turbo sets. The parameters recorded in control room pressure and temperature of line stream, re-heat steam, feed water, fuel oil flow, mill outlet temperature, turbine speed, control valve operation, turbine shaft, axial shaft, back pressure in condenser, metal temperature etc.

Turbine governing System: - The main purpose of turbine governing is to maintain the desired speed of the turbine during fluctuation of the load on the generator by varying the steam input to the turbine.

www.google.co.in

http://en.wikipedia.org/wiki/Thermal_power_station

http://www.rrvunl.com/suratgarh thermal power station.php

References

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