Submitted by

Vivek Kumar Maurya

Roll No.- 1002237

Mechanical Engineering

7th semester

KIIT University

Bhubaneswar

Introduction To Thermal Power Plant (Steam power plant)

Thermal Power Plants – 75%Hydro Electric Power Plants - 20%Nuclear Power Plants - 3%Installed wind power Generation – 2%30% to 40% of electrical power is lost in

transmission and distribution.

Electricity Generation Sources

GENERAL LAYOUT OF THERMAL POWER PLANT

Coal is delivered to the plant by Railway Road Arial ropeways, .

Following are the processes depending on the capacity of

the plant. 

Unloading process Feeding process Screening process Crushing process Stacking process & Reclaiming process Bunkering process

  COAL HANDLING PLANT

Power Plant Cycle

Feed Water Cycle Steam Cycle Condensate Cycle Cooling Water Cycle

Air And Flue Gas Cycle

Power Plant Cycles

Feed Water Cycle

 Deaerator•Remove oxygen from feed water to steam generating boiler.•Protect from corrosions in feed water pips.•Remove unwanted dissolved CO2 gases.

Boiler Feed Water Pump

Pump feed water into a steam boiler.These pumps are normally high pressure unit.These are can be of the centrifugal pump type or positive

displacement type.

Heaters

Pre-heat water delivered to steam generating boiler . Improves the thermodynamic efficiency of the system. 1.  H.P Heater: (High pressure heater) -Heats the feed

water by exchanging heat with the steam that is extracted from the H.P. Turbine from different stages at different pressure.

2.  L.P. Heater: (Low Pressure heater)- Heats the water but it take the steam extraction from the L.P. turbine.

EconomiserTubular heat transfer surfaces used to preheat

boiler feed water before it enters the steam drum (same like heaters)

Extract heat from the flue gas before it is exhausted to the atmosphere .

Increases overall boiler thermal efficiency.

Boiler

Rectangular furnace about 50 feet (15 m) on a side and 130 feet (40 m) tall. Its walls are made of a web of high pressure steel tubes.

Steam Cycle

BOILER DRUM ( STEAM DRUM)

It is a reservoir of water/steam at the top end of the water tubes. It acts as a phase-separator for the steam/water mixture

SUPER HEATER 

Convert wet, saturated steam into dry steam (high temp and press) known as superheating.

Dry steam contains more thermal energy and increases the overall efficiency of the cycle by increasing Turbine work.

TURBINE

Extracts thermal energy from pressurized steam and convert into mechanical work on a rotating output shaft.

Steam turbines are split into three separate stages, 1) High Pressure (HP) – some fraction of steam sends to boiler

to reheat. 2) Intermediate Pressure (IP) – Reheated steam returns here

and sends to LP. 3) Low Pressure (LP)

CONDENSATE CYCLE

CONDENSER 

Steam is condensed by exchanging heat from circulating water coming from Cooling Towers.

Pressure is maintained below atmospheric pressure.

CONDENSER TUBE MATERIAL Copper based alloy (ASTM B 111, B543) Stainless steel (ASTM A268, B268, 1249, A213, A269) Titanium (ASTM B 338 Gr 1&2) Carbon steel (ASTM A 179, A214)

FUNCTION OF CONDENSER

Create a vacuum by condensing steam.

Remove dissolved non-condensable gases from condensate.

Providing a leak-tight barrier between the high grade condensate contained within the shell and the cooling water.

HOT WELL

The condenser hot well serves as a water reservoir for the turbine cycle.

Supply make-up water to the cycle.

 

 

Condensate Extraction Pump (CEP)

An extraction pump is an important part of a feed water system

Generally, fitted in between the condenser and de-aerator

To maintain the amount of condensate in the condenser

To provide the sufficient suction head to the extraction pump

COOLING TOWER

Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere

It works of the principle of heat transfer by convection. Heat lost by the water = Heat gain by the air

The towers vary in size from small roof-top units to very large hyperboloid structures (as in Image ) that can be up to 200 metres tall and 100 metres in diameter

Air and flue gas cycle

Flue gas is the gas exiting to the atmosphere through a pipe or channel.

Quite often, the flue gas refers to the combustion exhaust gas produced at power plants.

It usually consist of mostly nitrogen (typically more than two-thirds) from the combustion air, CO2, and water vapour as well as excess oxygen

It further contains a small percentage of a number of pollutants, such as particulate matter(like soot),carbon monoxide, nitrogen oxides, and sulphur oxides.

Forced Draft Fans (FD FANS):- 

Supply necessary air for fuel combustion by pushing the air through the combustion air supply system and into the furnace.

These fans are typically the most efficient fans in the power plant . Typically, these fans are centrifugal fans. 

Induced Draft Fans (ID FANS):- 

Placed at the outlet of the boiler system. It exhaust all gaseous combustion products, or flue gas, from the

boiler by creating a negative pressure or suction within the furnace.  

Primary Air Fans (PA FANS):- 

Primary air fans (PA) are high pressure fans . Supply air for the transportation of coal directly from the

pulverizer to the furnace .

 

By lowering Condenser Pressure By ReheatingBy SuperheatingBy RegenerationModified Rankine cycle

Way To Increase efficiency of cycle

Electrostatic Precipitators(ESP):-

Particulate collection devices that remove particles from a flowing gas (e.g. air) by using the force of an induced electrostatic charge.

They can easily remove fine particulate matter such as dust and smoke from the air stream.

Selection Of site:-

Availability of cheap land.Availability of water.Availability of fuel.Possibility of future expansion of the plant.Away from the urban areas due to pollution.The initial cost of plant.Magnitude and nature of load to be handled.

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