Presented by:-Keyur Prajapati 100230106001Shah Jinal 100230106002Patel Vishal 100230106003Shangani Shivam 100230106004Padsala Ketul 100230106005

Guided By :-

INTRODUCTION

SOURCES OF ENERGY

CONVENTIONAL ENERGY SOURCES

NON CONVENTIONAL ENERGY SOURCES

RENEWABLE ENERGY RESOURCES

NON RENEWABLE ENERGY RESOURCES`

These are the energy resources, which we are using to generate power for the past 200 years.

Ex : Thermal, Hydel, Nuclear.

NON CONVENTIONAL ENERGY SOURCES :

These are the energy resources, which are rarely used to generate power.

Ex : Wind, solar, Tidal, Geo-Thermal, Ocean….

RENEWABLE ENERGY RESOURCES:

NON RENEWABLE ENERGY RESOURCES

These are the energy resources, which are available in large quantity in earth & they are continuously restored by nature.

Ex : Wind, solar, Tidal, Geo-Thermal, Ocean…. Hydel, Nuclear.`

The availability of these energy resources decreasing day by day due to continuous usage (exhaustible).

Ex : Thermal, Coal, Diesel, Natural gas.

A power plant is a facility to generate electric power with continuous energy

conversion

Heat Energy

Mechanical Energy

Electrical Energy

Steam (or) Thermal Power Plant Hydro Power Plant Nuclear Power Plant Diesel Power Plant Gas Turbine Power Plant Solar Power Plant Wind Power Plant Geo Thermal Power Plant Tidal Power Plant

• A thermal power station is a power plant in which the prime mover is steam driven.• Water is heated, turns into steam and spins a steam turbine which either drives an electrical generator or does some other work, like ship propulsion.

A power station ( generating station, power plant or powerhouse) is industrial facility for the generation of electric power.

A thermal power station is a power plant in which the prime mover is steam driven. Water is heated, turns into steam and spins a steam turbine which drives an electrical generator. After it passes through the turbine, the steam is condensed in a condenser and recycled to where it was heated; this is known as a Rankine cycle.

Power plants burning coal, fuel oil, or natural gas are often called thermal power plants.

Thermal power plants contribute maximum to the generation of Power for an country. In India more then 60% of power plants is thermal power plant.

• Reciprocating steam engines have been used for mechanical power sources since the 18th Century, with notable improvements being made by James Watt . • The very first commercial central electricalgenerating stations in New York and London, in 1882, also used reciprocating steam engines. • As generator sizes increased, eventually turbines took over.

James Watt

T

2 3

41

P

v

1

2 3

4

Boiler

TurbineCompressor(pump)

Heat exchanger

1

2 3

4

Qout

Qin

Wout

Win

In these types of cycles, a fluid evaporates and condenses.

Ideal cycle is the Carnot

Which processes here would cause problems?

Objectives: design an optimal vapor power cycle use idealized Carnot cycle as the model; consider all theoretical and practical limitations and

redesign the cycle accordingly Idealized Rankine cycle; optimize the Rankine cycle using concepts of superheating,

reheating and regeneration; discussion concerning the increase of the efficiency of an

idealized Rankine cycle. Carnot cycle

T

s

2 3

41

OR

T2 3

41(a) (b)

s

• Idealized thermodynamic cycle consisting of four reversible processes (any substance):

Reversible isothermal expansion (1-2, TH=constant) Reversible adiabatic expansion (2-3, Q=0, THTL) Reversible isothermal compression (3-4, TL=constant) Reversible adiabatic compression (4-1, Q=0, TLTH)

1-2 2-3 3-4 4-1

Work done by gas = PdV, area under the process curve 1-2-3.

1

2

3

32

1

Work done on gas = PdV, area under the process curve 3-4-1

subtract

Net work1

2

34

dV>0 from 1-2-3PdV>0

Since dV<0PdV<0

• The efficiency of an irreversible heat engine is always less than the efficiency of a reversible one operating between the same two reservoirs. th, irrev < th, rev

• The efficiencies of all reversible heat engines operating between the same two reservoirs are the same. (th, rev)A= (th, rev)B

• Both Can be demonstrated using the second law (K-P statement and C-statement). Therefore, the Carnot heat engine defines the maximum efficiency any practical heat engine can reach up to.

• Thermal efficiency th=Wnet/QH=1-(QL/QH)=f(TL,TH) and it can be shown that th=1-(QL/QH)=1-(TL/TH). This is called the Carnot efficiency.

• For a typical steam power plant operating between TH=800 K (boiler) and TL=300 K(cooling tower), the maximum achievable efficiency is 62.5%.

Let us analyze an ideal gas undergoing a Carnot cycle between two temperatures TH and TL.

1 to 2, isothermal expansion, U12 = 0QH = Q12 = W12 = PdV = mRTHln(V2/V1)

2 to 3, adiabatic expansion, Q23 = 0(TL/TH) = (V2/V3)k-1 (1)

3 to 4, isothermal compression, U34 = 0QL = Q34 = W34 = - mRTLln(V4/V3)

4 to 1, adiabatic compression, Q41 = 0(TL/TH) = (V1/V4)k-1 (2)

From (1) & (2), (V2/V3) = (V1/V4) and (V2/V1) = (V3/V4)th = 1-(QL/QH )= 1-(TL/TH) since ln(V2/V1) = ln(V4/V3)

It has been proven that th = 1-(QL/QH )= 1-(TL/TH) for all Carnot engines since the Carnot efficiency is independent of the working substance.

A Carnot heat engine operating between a high-temperature source at 900 K and reject heat to a low-temperature reservoir at 300 K. (a) Determine the thermal efficiency of the engine. (b) If the temperature of the high-temperature source is decreased incrementally, how is the thermal efficiency changes with the temperature.

th

L

H

th H

H

th H

L

T

T

K

TT

K

TT

1 1300

9000 667 66 7%

300

1300

900

1900

. .

( )

( )

( )

( )

Fixed T and lowering T

The higher the temperature, the higher the "quality"

of the energy: More work can be done

Fixed T and increasing T

L H

H L

200 400 600 800 10000

0.2

0.4

0.6

0.8

1

Temperature (TH)

Eff

icie

ncy

Th( )T

T

200 400 600 800 10000

0.2

0.4

0.6

0.8

1

Temperature (TL)

Eff

icie

ncy

TH( )TL

TL

Lower TH

Increase TL

• Similarly, the higher the temperature of the low-temperature sink, the more difficult for a heat engine to transfer heat into it, thus, lower thermal efficiency also. That is why low-temperature reservoirs such as rivers and lakes are popular for this reason.

•To increase the thermal efficiency of a gas power turbine, one would like to increase the temperature of the combustion chamber. However, that sometimes conflict with other design requirements. Example: turbine blades can not withstand the high temperature gas, thus leads to early fatigue. Solutions: better material research and/or innovative cooling design.

• Work is in general more valuable compared to heat since the work can convert to heat almost 100% but not the other way around. Heat becomes useless when it is transferred to a low-temperature source because the thermal efficiency will be very low according to th=1-(TL/TH). This is why there is little incentive to extract the massive thermal energy stored in the oceans and lakes.

• Maximum temperature limitation for cycle (a). What is the maximum temperature in the cycle?• Isentropic expansion in a turbine from 3-4. What is the quality of the steam inside the turbine? Will high moisture content affect the operation of the turbine?• Isentropic compression process in a pump from 1-2. Can one design a condenser and transmission line system that precisely control the quality of the vapor in order to achieve an isentropic compression? Even we can, is it practical to handle two-phase flow (liquid + vapor) using such a system? • The latter two problems can be resolved by the use of cycle (b) from previous slide. However, the (b) cycle requires the compression(1-2)of liquid at a very high pressure (exceeding 22 MPa for a steam, how do I get this number from?) and that is not practical. Also, to maintain a constant temperature above the critical temperature is also difficult since the pressure will have to change continuously.

To avoid transporting and compressing two-phase fluid, we can try to condense all fluid exiting from the turbine into saturated liquid before compressed it by a pump. T

s

• when the saturated vapor enters the turbine, its temperature and pressure decrease and liquid droplets will form by condensation. These droplets can produce significant damages to the turbine blades due to corrosion and impact. One possible solution: superheating the vapor. It can also increase the thermal efficiency of the cycle.

3

41

2

This cycle follows the idea of the Carnot cycle but can be practically implemented.

1-2 isentropic pump 2-3 constant pressure heat addition

3-4 isentropic turbine 4-1 constant pressure heat rejection

h1=hf@ low pressure (saturated liquid) Wpump (ideal)=h2-h1=vf(Phigh-Plow)

vf=specific volume of saturated liquid at low pressure

Qin=h3-h2 heat added in boiler (positive value) Rate of heat transfer = Q*mass flow rate Usually either Qin will be specified or else the

high temperature and pressure (so you can find h3)

Qout=h4-h1 heat removed from condenser (here h4 and h1 signs have been switched to keep this a positive value)

Wturbine=h3-h4 turbine work Power = work * mass flow rate

h4@ low pressure and s4=s3

An ideal Rankine cycle operates between pressures of 30 kPa and 6 MPa. The temperature of the steam at the inlet of the turbine is 550°C. Find the net work for the cycle and the thermal efficiency. Wnet=Wturbine-Wpump OR Qin-Qout

Thermal efficiency th=Wnet/Qin

Pump is not ideal

Turbine is not ideal

There will be a pressure drop across the boiler and condenser

Subcool the liquid in the condenser to prevent cavitation in the pump. For example, if you subcool it 5°C, that means that the temperauture entering the pump is 5°C below the saturation temperature.

pump

factual

actual

idealpump

PPvWW

W 12

equation pump theof inversean is that thisnote ideal

actualturbine W

W

Thermal efficiency can be improved by (a) Lowering the condensing pressure (lower

condensing temperature, lower TL) (b) Superheating the steam to higher temperature ( c) Increasing the boiler pressure (increase boiler

temperature, increase TH)T

s

1

2

3

4

(a) lower pressure(temp)

s

T

1

2

3

4

s

T

1

2

(b) Superheating

( c) increase pressure

Low quality,high moisture content

The optimal way of increasing the boiler pressure but not increase the moisture content in the exiting vapor is to reheat the vapor after it exits from a first-stage turbine and redirect this reheated vapor into a second turbine.

boiler

high-Pturbine

Low-Pturbine

pump

condenser1

2

3

4

56

T

s

1

2

3 5

6

4

high-Pturbine

low-Pturbine

Reheating allows one to increase the boiler pressure without increasing the moisture content in the vapor exiting from the turbine.

By reheating, the averaged temperature of the vapor entering the turbine is increased, thus, it increases the thermal efficiency of the cycle.

Multistage reheating is possible but not practical. One major reason is because the vapor exiting will be superheated vapor at higher temperature, thus, decrease the thermal efficiency. Why?

Energy analysis: Heat transfer and work output both change qin = qprimary + qreheat = (h3-h2) + (h5-h4)

Wout = Wturbine1 + Wturbine2 = (h3-h4) + (h5-h6)

From 2-2’, the temperature at 2 is very low, therefore, the heat addition process is at a lower temperature and therefore, the thermal efficiency is lower. Why?

Use regenerator to heat up the liquid (feedwater) leaving the pump before sending it to the boiler, therefore, increase the averaged temperature (efficiency as well) during heat addition in the boiler.

T

s1

2

2’

3

4

Lower tempheat addition

T

s1

23

4

5

6

7

Use regenerator to heat up the feedwater

higher tempheat addition

Extract steam fromturbine to provideheat source in theregenerator

Improve efficiency by increasing feedwater temperature before it enters the boiler.

Open feedwater: Mix steam with the feedwater in a mixing chamber.

Closed feedwater: No mixing.

Pump 24

Pump 1

OpenFWH

boiler

condenser1

23

5

67

1

23

4

5

6

7

T

s

Open FWH

(y) (1-y)

(y)

(1-y)

Assume y percent of steam is extracted from the turbine and is directed into open feedwater heater.

Energy analysis:qin = h5-h4, qout = (1-y)(h7-h1),Wturbine, out = (h5-h6) + (1-y)(h6-h7)Wpump, in = (1-y)Wpump1 + Wpump2

= (1-y)(h2-h1) + (h4-h3)= (1-y)v1(P2-P1) + v3(P4-P3)

In general, the more feedwater heaters, the better the cycle efficiency.

Steam power plant basically operates on the RANKINE cycle. Coal is burnt in a boiler, which converts water into steam. The steam is expanded in a turbine, which produces mechanical power driving the alternator coupled to the turbine. The steam after expansion in prime mover is usually condensed in a condenser to be fed into the boiler again. In practice, however, a large no. of modifications and improvements have been made so as to affect economy and improve the thermal efficiency of the plant

Working Principle :

Coal is burnt in the furnace which releases the heat energy.

This heat energy is used to convert the water into high pressure steam in the boiler.

This high pressure & high temperature steam is passed through the turbine, Which rotates the turbine shaft. (where the heat energy is converted into mechanical energy)

The turbine is coupled with the generator to produce the electrical energy.

The steam coming out of the turbine passes through the condenser, where the steam is condensed into water and then circulated to the boiler.

1. Cooling tower 10. Steam governor valve 19. Superheater2. Cooling water pump 11. High pressure turbine 20. Forced draught fan3. Transmission line (3-phase) 12. Deaerator 21. Reheater4. Unit transformer (3-phase) 13. Feed heater 22. Air intake5. Electric generator (3-phase) 14. Coal conveyor 23. Economiser6. Low pressure turbine 15. Coal hopper 24. Air preheater7. Boiler feed pump 16. Pulverised fuel mill 25. Precipitator8. Condensor 17. Boiler drum 26. Induced draught fan9. Intermediate pressure turbine 18. Ash hopper 27. Chimney Stack

OPERATIONS OF A THERMAL POWER STATION:

Below is a Diagram of the Basic Operation of a Thermal Power Station.

•We used coals as fuel for the generation of heat energy. As the water in the Boiler evaporated due to the intense heat, it becomes high-pressurized steams.  • And the steams are passing through a conduit , it forces its way through the Turbine, thus rotating the Turbine. • The Turbine is connected to a Generator via a coupler. As the Turbine is rotating electrical energy is being produced.• After the steams have passed through the turbine, it enters a Condenser. The Condenser has got a cooling agent and the steam will go through the cooling agent via a pipe.

The steam thus changes back to its liquid form and returns to the Boiler.

  Then the quantity of coal required per hour would be given by Weight of Coal Required ==> Capacity * Steam Requirement * Heat Delivered/Calorific Value of Coal * Efficiency of Boiler

  

In general, both the construction and operation of a power plant requires the existence of some conditions such as water resources and stable soil type.. The following list corers most of the factors that should be studied and considered in selection of proper sites for power plant construction: •Transportation network: Easy and enough access to transportation network is required in both power plant construction and operation periods.

•Gas pipe network: Vicinity to the gas pipes reduces the required expenses

•Power transmission network: To transfer the generated electricity to the consumers, the plant should be connected to electrical transmission system.Therefore the nearness to the electric network can play a roll

•Geology and soil type: The power plant should be built in an area with soil and rock layers that could stand the weight and vibrations of the power plant. •Earthquake and geological faults: Even weak and small earthquakes can damage many parts of a power plant intensively. Therefore the site should be away enough from the faults and previous earthquake areas. •Topography: It is proved that high elevation has a negative effect on production efficiency of gas turbines. In addition, changing of a sloping area into a flat site for the construction of the power plant needs extra budget. Therefore, the parameters of elevation and slope should be considered.

Water resources: For the construction and operating of power plant different volumes of water are required. This could be supplied from either rivers or underground water resources. Therefore having enough water supplies in defined vicinity can be a factor in the selection of the site.

Population centers: For the same reasons as above, the site should have an enough distance from population centers.

Environmental resources: Operation of a power plant has important impacts on environment. Therefore, priority will be given to the locations that are far enough from national parks, wildlife, protected areas, etc.

Steam generator: In fossil-fueled power plants, steam generator refers to a furnace that burns the fossil fuel to boil water to generate steam.

The steam generating boiler has to produce steam at the high purity, pressure and temperature required for the steam turbine that drives the electrical generator.

A fossil fuel steam generator includes an economizer, a steam drum, and the furnace with its steam generating tubes and superheater coils.

Necessary safety valves are located at suitable points to avoid excessive boiler pressure.

Boiler: Boiler is a cylindrical closed vessel made from the steel is called boiler. In which by boiling water high pressure stem can be produce.

In boiler coal is mainly used as fule.The other material like oil , wood, gas, sawdust ,bagasse etc are used as fuel.

Boiler is a heart of the thermal power plant system

The types of boilers use in thermal power plant are as below:

(1)Circulating fluidzed bed boiler. (2)Water fired tube shell boiler. (3)Water tube boiler. (4)Fully automatic oil &and gas fired boiler.

Boiler furnace and steam drum Once water inside the boiler or steam generator,

the process of adding the latent heat of vaporization or enthalpy is underway.

The boiler transfers energy to the water by the chemical reaction of burning some type of fuel.

The water enters the boiler through a section in the convection pass called the economizer. From the economizer it passes to the steam drum.

Once the water enters the steam drum it goes down the down-comers to the lower inlet water-wall headers.

Superheater Fossil fuel power plants can have a superheater

and/or reheater section in the steam generating furnace

In a fossil fuel plant, after the steam is conditioned by the drying equipment inside the steam drum, it is piped from the upper drum area into tubes inside an area of the furnace known as the superheter.

Reheater:-

Power plant furnaces may have a reheater section containing tubes heated by hot flue gases

outside the tubes. Exhaust steam from the high pressure turbine is rerouted to go inside the

reheater tubes to pickup more energy to go drive intermediate or lower pressure turbines. This is called thermal power plant.

Fuel preparation In coal-fired power stations, the raw feed coal

from the coal storage area is first crushed into small pieces and then conveyed to the coal feed hoppers at the boilers.

The coal is next pulverized into a very fine powder. The pulverizers may be ball mills, rotating drum grinders, or other types of grinders.

Some power stations burn fuel oil rather than coal. The oil must kept warm in the fuel oil storage tanks to prevent the oil from congealing and becoming un-pumpable.

The oil is usually heated to about 100 °C before being pumped through the furnace fuel oil spray nozzles.

Air path:External fans are provided to give sufficient air for combustion.

The forced draft fan takes air from the atmosphere and, first warming it in the air preheater for better combustion, injects it via the air nozzles on the furnace wall

• Auxiliary systems:• Fly ash collection: Fly ashis captured and removed

from the flue gas by electrostatic precipitators or fabric bag filters located at the outlet of the furnace and before the induced draft fan.

• The fly ash is periodically removed from the collection hoppers below the precipitators or bag

• Bottom ash collection and disposal: At the bottom of the furnace, there is a hopper for collection of bottom ash.

• This hopper is always filled with water to quench the ash and clinkers falling down from the furnace.

• Boiler make-up water treatment plant and storage: Since there is continuous withdrawal of steam and continuous return of condensate to the boiler, losses due to blow-down and leakages have to be made up to maintain a desired water level in the boiler steam drum. For this, continuous make-up water is added to the boiler water system.

Steam turbine-driven electric generator: The steam turbine generator being rotating

equipment generally has a heavy, large diameter shaft.

The shaft therefore requires not only supports but also has to be kept in position while running. To minimise the frictional resistance to the rotation, the shaft has a number of bearings

• Barring gear:• Barring gear or turning gear is the mechanism

provided to rotate the turbine generator shaft at a very low speed after unit stoppages

• Condenser :• The surface condenser is a shell and tube heat

exchanger in which cooling water is circulated through the tubes.

• The exhaust steam from the low pressure turbine enters the shell where it is cooled and converted to condensate by flowing over the tubes as shown in the adjacent diagram.

• For best efficiency, the temperature in the condenser must be kept as low as practical in order to achieve the lowest possible pressure in the condensing steam.

Since the condenser temperature can almost always be kept significantly below 100 °C where the vapor pressure of water is much less than atmospheric pressure, the condenser generally works under vacuum. Thus leaks of non-condensible air into the closed loop must be prevented

Feedwater heater: Preheating the feedwater reduces the irreversibilities involved in steam generation and therefore improves the thermodynamic efficiency of the system. This reduces plant operating costs and also helps to avoid thermalshock to the boiler metal when the feed-water is introduced back into the steam cycle.

Deaerator: Generally, power stations use a deaerator to

provide for the removal of air and other dissolved gases from the boiler feed water.

A deaerator typically includes a vertical, domed deaeration section mounted on top of a horizontal cylindrical vessel which serves as the deaerated boiler feed water storage tank.

There are many different designs for a deaerator and the designs will vary from one manufacturer to another

Auxiliary systems Oil system An auxiliary oil system pump is used to supply

oil at the start-up of the steam turbine generator.

Generator heat dissipation The electricity generator requires cooling to

dissipate the heat that it generates. While small units may be cooled by air drawn

through filters at the inlet, larger units generally require special cooling arrangements. Hydrogen

gas cooling, in an oil-sealed casing, is used because it has the highest known heat transfer

coefficient of any gas and for its low viscosity which reduces windage losses

Generator high voltage system The generator voltage ranges from 11 kV in

smaller units to 22 kV in larger units. The generator high voltage leads are normally

large aluminum channels because of their high current as compared to the cables used in smaller machines.

The generator high voltage channels are connected to step-up transformers for connecting to a high voltage electrical substation(of the order of 115 kV to 520 kV) for further transmission by the local power grid

Other systems Monitoring and alarm system Battery supplied emergency lighting and

communication

The four main circuits of the Thermal Power Plant :

i) Coal & Ash Circuitii) Air & Flue Gas Circuitiii) Feed Water & Steam Flow

Circuitiv) Cooling Water Circuit

ASH STORAGE

ASH HANDLING BOILER

COAL HANDLING

COALSTORAGE

Coal is used as the fuel & burnt in the boiler for the generation of steam.Ash is produced due to the combustion of coal and it is removed from the furnace and stored in the ash storage yard.

HOT AIR

Boiler

Dust collector

economiser

Draught fan

Air preheater

Hot flue gas

CHIMNEY

Fresh atmospheric air is supplied to the air preheater through fans. This fresh air is preheated by the hot flue gases. This Hot air is supplied to the Boiler. The hot flue gases leaves the boiler. The flue gas passes through the

dust collector for removing the dust particles. Then this hot flue gas is used to heat the feed water in the

Economiser & to preheat the atmospheric air in the Air preheater. Finally the flue gas leaves to the atmosphere through chimney.

Air from atmos.

The feed water enters into the Boiler tubes, in which the water is converted into steam.

This steam is further heated in the super heater to increase the pressure & temperature.

This high pressure high temperature steam passes through the steam turbine, where the heat energy of the steam is converted into mechanical energy.(ie . steam is used to rotate the turbine)

The superheated steam expands over the turbine blades and it drives the turbine shaft which is coupled to the electrical generator.

Then the expanded steam passes to the condenser where it is condensed to water.

The condensate (water) leaving the condenser is passing through the economizer where it is further heated by means of flue gases and recirculated into the boiler.

This circuit consists of condenser, cooling water pumps and Cooling Tower.

The hot water coming from the condenser is cooled in the cooling tower and it is re-circulated.

Abundant quantity of water is required for condensing the steam in the condenser which is taken from river or lake.

•Steam is generated in the boiler of the thermal power plant using heat of the fuel burnt in the combustion chamber. •The steam generated is passed through steam turbine where part of its thermal energy is converted into mechanical energy which is further used for generating electric power. •The steam coming out of the steam turbine is condensed in the condenser and the condensate is supplied back to the boiler with the help of the feed pump and the cycle is repeated. •The function of the Boiler is to generate steam. The function of the condenser is to condense the steam coming out of the low pressure turbine.

The function of the steam turbine is to convert heat energy into mechanical energy.

The function of the condenser is to increase the pressure of the condensate from the condenser pressure to the boiler pressure.

The other components like economizer, super heater, air heater and feed water heaters are used in the primary circuit to increase the overall efficiency of the plant

 

The overall efficiency of a steam power station is quite low (about 29%) mainly due to 2 reasons. Firstly, a huge amount of heat is lost in the condenser and secondly heat losses occur at various stages of the plant.

THERMAL EFFICIENCY:

η(thermal) =

OVERALL EFFICIENCY:

η(overall) =

Initial cost is low compared to hydel plant.

Generation of power is continuous.Less space is required.It can respond to rapidly changing load.

It can be located near the load centre, hence transmission cost & losses are reduced.

Transportation & handling of fuel is major difficulty.

Long time required for erection. Maintenance & operation cost are high. Efficiency of the plant is less. Power generation cost is high compared to

hydel power plants. Coal resources are depleting continuously. Life of the power plant is comparatively

less.

PROCESS INVOLVED IN THERMAL POWER PLANT STATION

Coal, oil, gas and hydroelectric potential constitute the conventional sources of electricity generation. Total installed capacity of electricity generation in India is approx. 98,668 MW.

India ranked third in the world with 7 percent coal reserves of the total world reserves.

Coal production increased from 30 million tonnes to over 348 million tonnes in 1999. Expected to increase to 427 million tonne in 2010.

Seventy percent of the total coal produced is consumed for power generation. Steel & cement are other major consumers.

COAL AND ENERGY SCENARIO IN INDIA

Coal, oil, gas and hydroelectric potential constitute the conventional sources of electricity generation. Total installed capacity of electricity generation in India is approx. 98,668 MW.

India ranked third in the world with 7 percent coal reserves of the total world reserves.

Coal production increased from 30 million tonnes to over 348 million tonnes in 1999. Expected to increase to 427 million tonne in 2010.

Seventy percent of the total coal produced is consumed for power generation. Steel & cement are other major consumers.

COAL AND ENERGY SCENARIO IN INDIA

THE PRINCIPAL INVOLVED IN THE CLASSICAL POWER PLANT

Source India Japan U.S.Coal 59.2% 21.2% 51.8%

Oil 13.9% 16.6% 03.1%

Gas 06.3% 22.1% 15.7%

Nuclear 02.5% 30.0% 19.9%

Hydro 17.8% 08.2% 07.4%

Others 00.3% 01.9% 02.2%

ENVIRONMENTAL ISSUES IN COAL BASED POWER GENERATION

Air Pollution :- High particulate matter emission levels due to burning of inferior grade coal which leads to generation of large quantity of flyash

Emissions of SO2, NOx & Green house gas (CO2) are also matter of concern

Water Pollution :- Mainly caused by the effluent discharge from ash ponds, condenser cooling /cooling tower, DM plant and Boiler blow down.

Noise Pollution :- High noise levels due to release of high pressure steam and running of fans and motors

Land Degradation :- About 100 million tonnes of fly ash is generated by use of coal far energy production. The disposal of such large quantity of fly ash has occupied thousands hectares of land which includes agricultural and forest land too.

1.)DEADLY EFFECTS OF POLLUTION WHICH IS GIVEN OUT AS A BIO PRODUCT IN THERMAL POWER PLANT PROCESS.2.) IT IS GREAT HAZARD TO THE HUMAN AS WELL AS FOR OUR ENVIRONMENT.3.) DUE TO HARMFULL GAS EMMISSION DURING PROCESS IT HAS GREAT IMPACT ON THE HUMAN BRAIN ..)

Seventy one per cent of electricity production is based on coal and gas in the country.

83 coal based thermal power plants with total generation capacity of 62880.9 MW (as on July, 2003)

27 gas/naphtha based power plants with total generation capacity of 11299.6 MW (as on July, 2003)

More than 240 million tonnes of coal with ash content 35-45% is consumed annually by the Thermal Power Plants.

3715 MT/day of SO2 is emitted from coal based power plants,which is 89% of total emission of SO2 from industries in India

Nearly 100 million tonnes per annum coal ash is generated.

More than 25,000 hectares of land has been occupied for conventional disposal of ash.

More than 630 million M3 water is required for disposal of coal ash as in slurry form per annum

Pollutants Emissions (in tones/day)

CO2 424650

Particulate Matter

4374

SO2 3311

NOx 4966

Share of Suspended Particulate Matter Load (tonnes/day) by Different Categories of

Industries (With Control Device), Total Load = 5365 tonnes/day

Sugar10%

Thermal Power Plants82%

Others 1%

Cement7%

Others1%

Oil Refineries3%

Sulphuric Acid Plants

2%

Thermal Power Plants89%

Steel5%

Share of Sulphur Dioxide Load (Tonnes / day)Share of Sulphur Dioxide Load (Tonnes / day)By different categories of IndustriesBy different categories of Industries

(Total Load = 3715 Tonnes / day)(Total Load = 3715 Tonnes / day)

EMISSION STANDARDS FOR THERMAL POWER PLANTS

Depending upon the requirement of local situations, which may warrant stricter standards as in case of protected areas the State Pollution Control Board within the provisions of the Environmental (Protection) Act, 1986, may be prescribed limit of 150 mg/Nm3 irrespective of the generation capacity of the plant

Power Generation Capacity

Particulate Matter Emission

< 210 MW 350 mg/Nm3

= > 210 MW 150 mg/Nm3

For the proper dispersion of SO2 emission from thermal power plant, stack height criteria have been adopted in country. However, for larger capacities boilers (500MW and above) space provision for installing FGD system has been recommended.

Power generation capacity

Stack Height (mts.)

Less than 200/210 MW H = 14 (Q) 0.3 , where Q is emission rate of SO2 in kg/hr,

H= Stack Height 200/210 or less than 500

MW 220

500 MW and above 275

STACK HEIGHT REQUIREMENTS

Total number of power plants : 81 

Air Pollution

         Power plants complying with emission : 43 standards         Power plants not complying with emission : 35 standards         Power plants closed : 03 

Water Pollution          Power plants complying with ash pond : 49 Effluent standards         Power plants not complying with ash pond : 29 Effluent standards         Power plants closed : 03

 

        Inconsistent supply of coal

        High resistivity of coal

        Inefficient operation of ESPs

        Delay in supply of ESPs

       Low Specific Collection Area (SCA) of ESPs

        Inefficient management of ash ponds

        Large quantities of ash generation

Need for adoption of CCTs

To meet in creasing demand of power with minimal environmental impact for sustainable development, adoption of clean coal technologies with enhanced power plant efficiency, fuel switching, use of washed coal, efficient pollution control systems and proper by-product and waste handling & utilization, is necessary.

Classification :

Pre-combustion Technologies : Ash, sulphur and other impurities (coal benefaction) ca n be reduced from the coal before it is burned

Combustion technologies : Generation of emissions of SO2, NOx (FBC : CBFC, AFBC,PFBC, and CO2 can be minimised by

IGCC) adopting improved combustion technologies

Post combustion technologies : End of pipe treatment (installation pollution

control equipments such as ESP, DENOx & De SOx systems)

USE OF BENEFICIATED COALIn order to minimise fly ash generation, it was recommended to use beneficiated coal in the power plants. A Gazette notification has been issued under EPA, 1986, stating that :

“On and from the 1st day of June 2002, the following coal based thermal power plants shall use beneficiated coal with ash content not exceeding thirty four percent, namely :

Power plants located beyond 1000 km from the pit head and

Power plants located in urban area or sensitive area or critically polluted area irrespective of their distance from the pit head except any pit headed power plants.

The power plants based on FBC (CFBC, PFBC & AFBC) and IGCC technologies are exempted to use beneficiated coal irrespective of their locations.

Implementation of use of beneficiated coal in thermal power plant w.r.t. June 30, 2002, shall yield following benefits during 2002-03:Reduction in tonnage (MT) 11

Saving in transport cost (US M$) 240

Saving in Diesel consumption (KL) 63750

Reduction in Bottom Ash (MT) 2

Reduction in Fly Ash (MT) 8

Reduction in CO2 (MT) 23

Out of 81 coal based thermal Power plants, 39 plants are required to use beneficiated coal not containing ash more than 34% w.r.t. June 30, 2002.

Ministry of environment and forests has issued following directions under section 3 & 5 of Environment (Protection) Act, 1986 vide a Gazette notification no. GSR . 763 (E) dated 14/09/1999

Use of flyash, bottom ash or pond ash in the manufacture of bricks and other construction activities

Utilisation of flyash by thermal power plants and

Specifications for use of flyash based products by Government agencies

Out of 81 power plants, 52 power plants have been submitted their action plans remaining have been asked to submit action plans immediately.

Submission of action plans by the Submission of action plans by the power plantspower plants New Power PlantsNew Power Plants• 30 % flyash utilisation within 3 year30 % flyash utilisation within 3 year• 100 % flyash utilisation within 9 100 % flyash utilisation within 9 yearsyears

Existing Power PlantsExisting Power Plants• 20 % flyash utilisation within 3 20 % flyash utilisation within 3 yearyear• 100 % flyash utilisation within 15 100 % flyash utilisation within 15 yearsyears

Existing coal based power plants being monitored by the regulatory agencies and directions are issued

Use of Beneficiated Coal in Thermal Power Plants

Emphasis on clean technology for new plants

Emphasis on utilisation of fly ash Emphasis on non-carbon/low carbon based

technologies for power sector Emphasis on on cogeneration

SPACIFICATION OF THERMAL POWER PLANT:

(1)Power plant should be far away from the recidential area

(2)Plant should have enough space for the future implimention

(3)The physical west should be remove at proper place to avoid its harm effect.

(4)Plants machinery should be maintain well and their inspection must done the proper time interval

(5)Safety of the plant worker or employ should be maintain

(6)All machinery of plant should as per standard regulation by Government.

(7)Policy of worker and machinery should be paid at proper time

 

THERMAL POWER PLANT IN GUJARAT: (1)Gandhinagar thermal power station-870. (2)Ukai thermal power plant-850mw. (3)Wanakbori power plant-1470mw (4) Sikka thermal power station-240mw