A diesel power plant is the combination of a diesel engine with an electric generator to generate electrical energy. A diesel compression-ignition engine is usually designed to run on diesel fuel, but some types are adapted for other liquid fuels or natural gas.

1. Diesel
Power Plant
Submitted By:-
Patiwala Dishant K.

2. Introduction
• Diesel power plants produce power in the range of 2 to 50 MW, are used as
central stations for supply authorities and work.
• They are used as standby sets for continuity of supply such as hospitals,
telephone exchanges, radio stations, cinema theatres and industries.
• They are suitable for mobile power generation and widely used in railways and
ships.
• Used as Peak Load Plants, Mobile Plants, Stand By Units, Emergency Plants,
Starting Stations, Central Stations, Industries where power requirement is small
500kW.

3. Four Stroke Diesel Cycle Engine
• Intake or Suction Stroke
• Piston moves from TDC to BDC creating vacuum in the cylinder
• Intake valve opens allowing only air to enter the cylinder and exhaust valve
remains closed.
• Both valves stay closed
• Piston moves from BDC to TDC, compressing air to 22:1
• Compressing the air to this extent increases the temperature inside the cylinder to
above 600 degree centigrade.

4. Four Stroke Diesel Cycle Engine
• Both valves stay closed.
• When the piston is at the end of compression stroke(TDC) the injector sprays a
mist of diesel fuel into the cylinder.
• When hot air mixes with diesel fuel an explosion takes place in the cylinder.
• Expanding gases push the piston from TDC to BDC.
• Piston moves from BDC to TDC
• Exhaust valve opens and the exhaust gases escape
• Intake valve remains closed

5. Essential elements of Diesel
• Engine System
• Starting System
• Lubrication System
• Fuel System
• Air filter and Supercharge
• Cooling System
• Exhaust System
• Governing System

6. Diesel engine
• Diesel engine is a compression ignition(CI) engine.
• Thetwo –strokecycle engine is more favored for diesel power
plants.
• The air required for the diesel engine is drawn through the air filter
• from the atmosphere and compressed inside the cylinder.
• The fuel(diesel) from the diesel engine is drawn through a filter from the all day
tank and injected into the cylinder through fuel injectors.
• Because of the high temperature and pressure of the compressed air, the fuel
ignites.
• The fuel burns and the burnt gases expand to do work on the moving part inside
the cylinder called piston.
• This movement of the piston rotates a flywheel and the engine is directly coupled
to electric generator.
• The gases after expansion inside the cylinder is exhausted into the atmosphere
and passes through a silencer in order to reduce the noise.

7. Starting system
• Diesel engine used in diesel power plant is not self starting . The engine is started
from cold condition whit the help of an air compressor.

8. Air intake system
The air intake system conveys fresh air through pipes or ducts to the 4-stroke
engine, scavenging pump & to the supercharger.
A large diesel engine requires 0.076 to 0.114 m3 of air/min/KW of power
developed. Air is first drawn through a filter to catch dirt or particles that may
cause excessive wear in cylinders. Filters may be of following types:
a. Dry type (paper, cloth, felt, glass wool etc)
b. Wet type (oil impingement type, oil bath type where oil helps to catch particles)

9. Lubrication system
• It includes the oil pumps, oil tanks, filters, coolers and connecting pipes.
• The purpose of the lubrication system is to reduce the wear of the engine
moving parts
• Part of the cylinder such as piston , shafts , valves must be lubricated. The
lubricant is cooled before recirculation.
• Lubrication also helps to cool the engine.

10. Fuel supply system
• It includes the storage tank, fuel pump, fuel transfer pump, strainers and heater.
• Pump draws diesel from storage tank to day tank through the filter
• The day tank is usually placed high so that diesel flows to engine under
gravity.
• Diesel is filtered before being injected into the engine by the fuel injection
pump.

11. Fuel supply system

12. Exhaust system
• The purpose of the exhaust system is to discharge the engine exhaust to the
atm. outside the building.
• This includes the silencers and connecting ducts.
• The exhaust gases coming out of the engine is very noisy.
• silencer (muffler) is provide to reduce the noise.
• Exhaust pipe leading out of the building should be short in length with
minimum number of bends to provide as low a pressure loss as possible.
• Flexible tubing may be added in exhaust pipe to take care of misalignments and
expansion/contraction and also to isolate the system from engine vibrations.
• Each engine should have its independent exhaust system.
• Where possible, exhaust heat recovery should be made to improve plant thermal
efficiency. E.g., air heating, low pressure steam generation in diesel-steam
power plant etc

13. Exhaust system

14. Functions the fuel injection system
• Filter the fuel
• Meter the correct quantity of the fuel to be injected
• Time the injection process
• Regulate the fuel supply
• Secure fine atomization of fuel oil
• Distribute the atomized fuel properly in the combustion chamber
• Oil is atomized either by blast or pressure jet.
• In pressure jet atomization oil is forced to flow through spray nozzles at
pressure above 100 bar. It is known as solid injection

15. Classification of solid injection systems
Common rail injection system:
Individual pump injection system
Distributor system

16. Cooling system
The cooling system consists of a water source, pump and cooling towers. The
pump circulates water through cylinder and head jacket. The water takes away
heat form the engine and it becomes hot. The hot water is cooled by cooling
towers and re circulated for cooling.
There are two systems to circulate the water through the jacket,
• Gravity system
• Forced circulation system

17. Cooling system

18. Supercharging
• The purpose of supercharging is to raise the volumetric efficiency above that
value which can be obtained by normal aspiration.
• The engine is an air pump, increasing the air consumption permits greater
quantity of fuel to be added, and results in greater potential output.
• The power output is almost directly prop. To the air consumption.
• methods to increase the air consumption of an engine are:
1. Increasing the piston displacement: leads to more size and weight, cooling
problems
2. Running the engine at higher speeds leads to mechanical wear and tear.
3. Increasing the density of the charge, so that greater mass of charge is
introduced in same volume.

19. Effects of Supercharging
• The Power output of a supercharged engine is higher than its naturally aspirated
counterpart.
• The mechanical efficiencies are better thannaturally aspirated engines.
• It has higher specific fuel consumption that naturally aspirated engines.

20. Simple layout

21. ADVANTAGE OF DIESEL POWER PLANT
1.Very simple design also simple installation and occupies less space.
2.Limited cooling water requirement.
3.Diesel power plant are more efficient than steam power in the range of 150MW
capacity.
4.Quickly started and put on load.
5.It can respond to varying loads without any difficulty.
6.Smaller storage is needed for the fuel.
7.Layout of power plant is quite simple.
8.There is no problem of ash handling.
9.Less supervision required.

22. Dishant Patiwala

23. Thank
you.