Generation of electricity from coal vol 1

Generation,

Transmission and

distribution of

electricity

BY:

M.SUNIL KUMAR

160711734043

Vol-1

2

In this Presentation

• Basic of Power Generation

• Basic information on Coal/Fuel Oil

• Combustion Process

• Power Plant Cycle

• Factors affecting Efficiency

• Boilers and Turbines

• Transmission of Power and Switching

3

How Generated electricity

reached customer

4

Simplified Diagram

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Coal to Electricity ….. Basics

Coal

Chemical Energy

Super Heated Steam

Pollutants

Thermal Energy

Turbine Torque

Heat Loss

In

Condenser

Kinetic Energy

Electrical Energy

Alternating current in Stator

Mech. Energy

LossASHHeat

Loss

Elet. Energy

Loss

PMI Revision 00 6

Major

Energy

Sources of

India

NR

WR

SR

ER

NER

Ennore

Kudankulam

Kayamkulam

Partabpur

Talcher/Ib Valley

Vindhyachal

Korba

MAJOR ENERGY RESOURCES IN INDIA

LEGEND

Coal

Hydro

Lignite

Coastal

Nuclear

Vizag

Simhadri

Kaiga

Tarapur

Mangalore

Krishnapatnam

RAPP

53,000MW

23,000MW

1,700MWSIKKIM

MY

AN

MM

AR

CHICKEN NECK

Cuddalore

SRI LANKACOLOMBO

NEPALBHUTAN

DESHBANGLA

South Madras

Pipavav

Generation Load-Centre

Kolkata

Bhubaneswar

Patna

Lucknow

Delhi

Mumbai

Chennai

Bangalore

Bhopal

Guwahati

Jammu

Ludhiana

Jaipur

Gandhinagar

Indore

Raipur

Thiruvananthapuram

Kozhikode

Hyderabad

* Hydro Potential : 1,10,000

> 25,000MW already installed

> 19,000MW under implementation

> 66,000MW still to be exploited

* 90% coal reserves in ER & WR

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Why Coal?

Share of Coal in Power

Generation

Advantages of Coal Fuel

•Abundantly available in India

•Low cost

•Technology for Power Generation well developed.

•Easy to handle, transport, store and use

Shortcomings of Coal

•Low Calorific Value

•Large quantity to be Handled

•Produces pollutants, ash

•Disposal of ash is Problematic

•Reserves depleting fast

•India’s Coal Reserves are estimated to be 206 billion tonnes. Present consumption is about 450 million tonnes.

•Cost of coal for producing 1 unit of electricity (Cost of coal Rs 1000/MT)is Rs 0.75.

•Cost of Gas for producing 1 unit of electricity (Cost of Gas Rs 6/SMC)is Rs 1.20.

Coal

55%

Gas

10%

Diesel

1%

Hydel

26%

RES

5%

Nuclear

3%

PMI Revision 00 8

Knowing more about Coal

Coal Transportation

•Rail

•Truck

•Conveyor

•Ship

Coal production

•Surface Mining

•Underground Mining

Coal Properties

•Calorific Value

•Grade of Coal (UHV)

•Proximate Analysis

•Ultimate Analysis

•Ash and Minerals

•Grindability

•Rank

•Physical Characteristics

Coal Beneficiation

•Why?

•Processes

•Effectiveness

Coal production

•Surface Mining

•Underground Mining

Useful Heat Value (UHV) UHV= 8900-138(A+M)

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Boiler/ steam generator

Steam generating device for a specific purpose.

Capable to meet variation in load demand

Capable of generating steam in a range of operating pressure and temperature

For utility purpose, it should generate steam uninterruptedly at operating pressure and temperature for running steam turbines.

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Boiler/ steam generator

• Raw materials for design of boilers

1. Coal from mines

2. Ambient air

3. Water from natural resources (river, ponds)

o Generating heat energy

o Air for combustion

o Working fluid for steam generation, possessing heat energy

A 500MW steam generator consumes about 8000 tonnes of coal every

day

It will be considered good, if it requires about 200 cubic meter of DM

water in a day

It will produce about 9500 tonnes of Carbon di Oxide every day

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Types of Boilers

• Fire-Tube Boilers Fire-tube

boilers rely on hot gases circulating

through the boiler inside tubes that are

submerged in water. These gases

usually make several passes through

the tubes, thereby transferring their

heat through the tube walls and

causing the water to boil on the other

side. Fire-tube boilers are generally

available in the range of 20 through

800 boiler horsepower (bhp) and in

pressures up to 150 psi.

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Types of Boilers

• Electric Boilers Electric

boilers are very efficient

sources of hot water or

steam, which are available in

ratings from 5 to over 50,000

kW. They can provide

sufficient heat for any HVAC

requirement in applications

ranging from humidification

to primary heat sources.

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Types of Boilers

• Water Tube Boiler: Here the heat source is outside the tubes and the water to be heated is inside. Most high-pressure and large boilers are of this type. In the water-tube boiler, gases flow over water-filled tubes. These water-filled tubes are in turn connected to large containers called drums.

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Steaming Capacity

Large boiler capacities are often given in Tonnes of

steam evaporated per hour under specified steam

conditions

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Coal analysis

• Typical composition (Proximate analysis)

1. Fixed carbon

2. Fuel ash

3. Volatile material

4. Total Moisture

5. Sulfur

o High calorific value/ Lower calorific value (Kcal/kg)

o Hardgrove Index (HGI)

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Combustion of coal

Carbon, hydrogen, sulfur are sources of heat on combustion

Surface moisture removed on heating during pulverization.

Inherent moisture and volatiles are released at higher temperature, making coal porous and leading to char/ coke formation. (Thermal preparation stage)

PMI Revision 00 17

Flame Inside Furnace

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Fuel Oil

Three liquid fuels used in power plants– 1. Heavy Fuel Oil (HFO)

– 2. LSHS (Low Sulfur Heavy stock)

– 3. High speed Diesel (HSD)

Oil firing is preceded by

Lowering viscosity and increasing flowability on heating for better combustion in given turn down ratio.(125oC)

Droplet formation on atomization (by steam/ compressed air/ mechanical pressurization)

Combustion initiation by High energy spark ignition

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Combustion of reactants

Reaction rate depends on concentration of one of the reactants

Concentration varies on partial pressure of the reactants.

Partial pressure is a function of gas temperature.

Therefore, reaction rate depends on temperature and substance that enter the reaction.

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Combustion Reactions

(Carbon)

• Main reactions

2C + O2 = 2CO + 3950 BTU/lb (Deficit air)

C + O2 = CO2 +14093 BTU/lb

Secondary reactions

2CO + O2 = 2CO2 + 4347BTU/lb C + CO2 =

2CO -7.25MJ/kg

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Combustion Reactions

(Carbon)• Carbon reaction

2C + O2 =2CO [Eco =60kJ/mol]

C + O2 =CO2 [Eco2 =140kJ/mol]

reaction at 1200oC

4C + 3O2 =2CO + 2CO2 (Ratio 1:1)

Reaction at 1700oC

3C + 2O2 = 2CO +CO2 (Ratio 2:1)

It is desirable to supply combustion air at lower temperature regime in furnace

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Combustion Reaction

(H2, S)

Hydrogen reaction

2H2 + O2 = 2H2O +61095 BTU/lb

Sulfur reaction

S + O2 = SO2 + 3980 BTU/lb (undesirable)

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Coal for combustion

Anthracite

Semi-anthracite

Bituminous

Semi-Bituminous

Lignite

Peat

High CV, low VM

High CV, low VM

Medium CV, medium VM

Medium CV, medium VM

Low CV, high VM, high TM

Very low CV, high VM & TM

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Basic Power Plant Cycle

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Factors Affecting Thermal

Cycle Efficiency

• Initial steam Pressure

• Initial Steam Temperature

• Whether reheat is used or not, and if used reheat

pressure and temperature

• Condenser pressure

• Regenerative feed water heating

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THANK YOU