101
CHAPTER NINE
9 OTHER POWER PLANTS
9.1 Diesel engine Power Plants
9.1.1 Introduction
A diesel power plant is suitable for small and medium outputs. It is used as a central
power station for smaller power supplies and as a standby plants to hydroelectric power
plants and steam power plants. They are in common use at capacities of up to 5 MW.
They are commonly used where
Fuel prices or reliability of supply favour oil over coal
Water supply is limited
Loads are relatively small
Electric line service is unavailable or available at high rates.
Diesel plants are more efficient than any other heat engine of comparable size. They are
cheap in terms of initial cost, can be started and stopped quickly and can burn a wide
range of fuels. They do not require any warming period and need not be kept running for a
long time before peaking up loads. Thus there are no standby losses. They do not need
large amounts of water for cooling and can be commissioned within a short time
compared to other plants such as hydro, steam or nuclear station.
9.1.2 Application of Internal combustion Engines
Internal combustion engines are used in stationary plants, marine power plants, in various
vehicles and aircrafts, their use in mobile units being dominant because of their low size
weight and fuel consumption.
Diesel Engines are mostly suitable for
1. Mobile power generation and are widely used in transportation systems consisting
of rail roads, ships, automobiles and aeroplanes
2. Electrical power generation for capacities ranging from .075 MW to 3.75 MW
3. Use as standby plants
4. Use as peak load plants for some other types of power plants
5. Use in industrial concerns where power requirements are small say of the order of
500 KW. Diesel plants become more economical due to their high overall
efficiency
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9.1.3 Components of a diesel electric power plant
The essential components of a diesel electric power plant are:
1. Engine
2. Engine air intake system
3. Engine fuel system
4. Engine exhaust system
5. Engine cooling system
6. Engine lubrication system
7. Engine starting system
9.1.4 Advantages and Disadvantages of diesel engine power plant
The advantages of a diesel engine power plant include the following
1. Plant layout is simple
2. Fuel handling is easier, and fuel requires small storage space. Also there is no
refuse to be disposed off. Oil transportation is also easier.
3. It can be located near the load centre
4. A diesel engine extracts more useful work from each heat unit than does any other
type of IC engine. Therefore, it becomes an attractive prime mover wherever the
initial cost is written offset and operating cost is the main cost to be met
5. The plant can be quickly started and can peak up load in a very short time
6. There are no standby losses
7. It does not require large amount of cooling water
8. The plant is smaller in size than steam power plants for the same capacity
9. The operation of the plant is easier and less labour is needed to operate the plant
10. Compared to steam power plants using steam turbine, the life of diesel power
plant is longer
11. Diesel engines operate at high thermal efficiency as compared to steam power
plants
Disadvantages
1. Diesel oil is costly
2. The plant does not work satisfactorily under overload conditions for longer times
3. Lubrication cost is high
4. The plant capacity is limited
MPE 571E: POWER PLANT ENGINEERING
CHAPTER NINE
9 OTHER POWER PLANTS
9.1 Diesel engine Power Plants
9.1.1 Introduction
A diesel power plant is suitable for small and medium outputs. It is used as a central
power station for smaller power supplies and as a standby plants to hydroelectric power
plants and steam power plants. They are in common use at capacities of up to 5 MW.
They are commonly used where
Fuel prices or reliability of supply favour oil over coal
Water supply is limited
Loads are relatively small
Electric line service is unavailable or available at high rates.
Diesel plants are more efficient than any other heat engine of comparable size. They are
cheap in terms of initial cost, can be started and stopped quickly and can burn a wide
range of fuels. They do not require any warming period and need not be kept running for a
long time before peaking up loads. Thus there are no standby losses. They do not need
large amounts of water for cooling and can be commissioned within a short time
compared to other plants such as hydro, steam or nuclear station.
9.1.2 Application of Internal combustion Engines
Internal combustion engines are used in stationary plants, marine power plants, in various
vehicles and aircrafts, their use in mobile units being dominant because of their low size
weight and fuel consumption.
Diesel Engines are mostly suitable for
1. Mobile power generation and are widely used in transportation systems consisting
of rail roads, ships, automobiles and aeroplanes
2. Electrical power generation for capacities ranging from .075 MW to 3.75 MW
3. Use as standby plants
4. Use as peak load plants for some other types of power plants
5. Use in industrial concerns where power requirements are small say of the order of
500 KW. Diesel plants become more economical due to their high overall
efficiency
MPE 571E: POWER PLANT ENGINEERING
, 102
9.1.3 Components of a diesel electric power plant
The essential components of a diesel electric power plant are:
1. Engine
2. Engine air intake system
3. Engine fuel system
4. Engine exhaust system
5. Engine cooling system
6. Engine lubrication system
7. Engine starting system
9.1.4 Advantages and Disadvantages of diesel engine power plant
The advantages of a diesel engine power plant include the following
1. Plant layout is simple
2. Fuel handling is easier, and fuel requires small storage space. Also there is no
refuse to be disposed off. Oil transportation is also easier.
3. It can be located near the load centre
4. A diesel engine extracts more useful work from each heat unit than does any other
type of IC engine. Therefore, it becomes an attractive prime mover wherever the
initial cost is written offset and operating cost is the main cost to be met
5. The plant can be quickly started and can peak up load in a very short time
6. There are no standby losses
7. It does not require large amount of cooling water
8. The plant is smaller in size than steam power plants for the same capacity
9. The operation of the plant is easier and less labour is needed to operate the plant
10. Compared to steam power plants using steam turbine, the life of diesel power
plant is longer
11. Diesel engines operate at high thermal efficiency as compared to steam power
plants
Disadvantages
1. Diesel oil is costly
2. The plant does not work satisfactorily under overload conditions for longer times
3. Lubrication cost is high
4. The plant capacity is limited
MPE 571E: POWER PLANT ENGINEERING
