Diesel power plant

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Gandhinagar Institute of Technology

Topic : Diesel Power PlantGuided By : Prof. Rahish Sir

Branch : Electrical

Batch : B1 Sem : 4th

Academic year : 2015-16(even)

Prepared by : Harshid Panchal (140120109023)

Subject Name And Code : Electrical Power Generation (2140908)Active Learning assignment

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Diesel power plant

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Introduction

A power station in which diesel engine used as the prime mover for the generation of electrical energy is called diesel power station.

In diesel power station, diesel used as the working fluid. The fuel(diesel) burns inside the engine cylinder and chemical energy of diesel is converted into the heat energy and this heat energy is converted into mechanical energy. Diesel engine coupled with alternator which converts mechanical energy into electrical energy.

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CHEMICAL ENERGY

MECHANICAL ENERGY

ELECTRICAL ENERGY

DIESEL ENGINE

ALTERNATOR

FUEL(DIESEL

)

ENERGY CONVERSION IN DIESEL POWER PLANT

RYB

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Diesel power station is very low capacity type as compare to steam and hydro power station.

Diesel engine is also called I.C. (Internal Combustion) engine for which the burning of fuel take place inside the engine. The main difference between the diesel engine and the steam engine is that in diesel engine the combustion of fuel take place inside the engine and steam engine combustion of fuel take place outside the engine.

6Line diagram of diesel power plant

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Essential elements of diesel power station

1) Diesel Engine : It is the main component of the diesel power station. The diesel engines are two stroke or four stroke type. It may be horizontal or vertical type. The diesel engine used as a prime mover which is directly coupled with the generator.

2) Generator : The main function of generator is to convert mechanical energy into electrical energy. Generator is mainly coupled with diesel engine. The generator used power station is salient pole type and rotating speed from 215 to 1000 r.p.m, capacity 25 to 5000 KVA and output voltage 440V for small machine and 2200 v for big machine.

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3) Exciter : It is small d.c. generator coupled to the main set used to produced required d.c. for excitation of the alternating field is winding.

4) Air Filter : The main function of air filter to remove dust and other suspended impurities from the air which is taken into the engine.

5) Silencer : The main function of silencer is to reduce noise when exhaust gas left out and also reduce noise pollution

6) Fuel Oil Tank : The fuel oil is stored in the fuel oil tanks which are situated outside the diesel engine room for safety.

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7) Strainer : Strainer is provided to remove suspended impurities and supply clean fuel to engine.

8) Transfer Pump : The main function of the transfer pump is to transfer fuel oil from the main tank to all day tank.

9) All day tank : The fuel oil which is transferred from fuel oil tank to small storage tank kept at some height is called all day tank. All day tank stored fuel oil as per the daily requirement.

10)Oil Filter : The main function of oil filter is to remove the dust particles and other impurities from the fuel oil.

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11)Fuel injection pump : fuel injection pump inject fuel oil to the engine cylinder at high pressure.

12)Hot well : Hot well is provided in the surge tank. The water takes away heat from the diesel engine and it self become hot. The hot water stored in Hot well.

13) Jacket water pump : The main function of jacket water pump is to transfer hot water from the hot well to heat exchanger.

14)Cooling tower : The cooling water which is absorbs heat from heat exchanger and become hot. This is cooled in a cooling tower and recirculated through the heat exchanger.

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15)Raw water pump : Raw water pump discharges cooling water from the cooling tower to heat exchanger.

16)Lubricating Oil tank : The life of the engine depend on the lubrication system. Lubricating oil stored in this tank.

17)Oil pump : Oil pump to pass lubricating oil to the oil filter.

18)Air compressor : The main function of air compressor is to compressed air at high pressure and it is admitted to cylinders of the engine. Compressed air system is mostly used for starting diesel engine.

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Comparison of I.C. Engine and External Combustion Engine

I.C. Engine1) The combustion of fuel

takes place inside the engine cylinder.

2) Diesel is used as the working fluid.

3) Fuel cost is high.4) Less capital cost.5) Required less space.6) Thermal efficiency is

high.7) Used in heavy duty

vehicles like truck, buses etc.

External Combustion Engine (steam engine)1) The combustion of fuel

takes place outside the engine cylinder.

2) Working fluid steam.3) Fuel cost is low.4) More capital cost.5) Required large space.6) Thermal efficiency is

low.7) Used in railway

locomotives, power station etc.

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THE WORKING OF 4 – STROKE DIESEL ENGINE.

Exhaust valve Inlet valve

airExhaust gases TDC

BDC

Fuel Injector

14WORKING OF 2-STROKE I.C. ENGINE

Comparison between 2 stroke and

4 stroke

Two stroke engine1) The cycle of

operation is completed in two stroke.

2) Simple construction.3) High working

efficiency.4) Produce more noise.5) They consume more

lubricating oil.6) These engines

required less space.

Four stroke engine1) The cycle of

operation is completed in four stroke.

2) Complicated construction.

3) Low working efficiency.

4) Produce less noise.5) They consume less

lubricating oil.6) These engines

required more space.

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Application of diesel power plant

1) Peak load plant : Diesel engine power plant can be easily started or stopped so it can be use in combination with thermal or hydro plants as a peak load plants.

2) Mobile Plant : Diesel plants mounted on trailers can be used for temporary or emergency purposes such as for suppling power to large civil engineering works.

3) Stand by Units : When any one unit of steam power station under maintenance period the diesel engine power station can operate in parallel to generate electric power.

4) Emergency Plant : In Industries where the process is such that continuous power supply is must when power from grid supply fails the diesel plant is run to meet with requirement of supply.

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Application of diesel power plant

5) Nursery station : When a new power station is constructed or in the absence of main grid, a diesel power station to supply power in a small town.

6) Starting station : Diesel power station can be used to run the auxiliaries for starting large steam power plant.

7) Central station : It is also used as central station where the capacity required is small

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Advantages of diesel power station

1) It can be located near load centre.2) Plant layout is simple.3) The plant can be quickly started and can pick up

load in very short time.4) There are no stand by losses.5) The plant is smaller in size than steam power plant

for the same capacity.6) The working life of diesel power plant is longer.

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Advantages of diesel power station

7) Capital cost is less.8) They require less cooling tower.9) Less civil engineering work is required.10)There is no ash handling problem.11)Easy lubrication system.12)Efficiency is higher.

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Disadvantages of diesel power plant

1) The plant can not work under overload condition for longer times.

2) Lubrication cost is high.3) The capacity of plant is limited.4) High operating cost.5) Noise problem.6) Capacity is restricted.7) Cost of fuel is high and vary with time to time.

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Site selection for diesel power station

1) Distance from load centre : It should be located near the load centre. This will minimize the cost of transmission lines and power losses through them.

2) Availability of water : Sufficient quantity of water should be available at the site selected for cooling purpose.

3) Foundation condition : The foundation condition of sub-soil should be such that a foundation at a reasonable depth should be capable of providing a strong support to the engine.

4) Access to the site : The site selected should have rail and road transportation facilities.

5) Fuel Transportation : The site selected should be nearer to the source of fuel(diesel) supply so that transportation charges low.

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References : Electrical Power Generation by Dr. D.M. Patel

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Engineering

Diesel power plant