Diesel Engine – Working Principle and Types of Diesel Engine
In this article we will learn about what is Diesel Engine, working principle of Diesel Engine, Types of Diesel Engines. The diesel engine is a type of internal combustion engine it is also known as CI Engine.Diesel Engine is invented by Rudolf Diesel in 1892 who is a German scientist. At first, the fuel used to run is coal dust. diesel engine has slower combustion characteristics as compared to petrol. The diesel engine produces high torque at low speed. heavy engines required a high torque to transmit the high rotation speed to the crankshaft, this helps the heavy vehicles to move.
Working Principle of Diesel Engine:
- The piston used to move in downward at first by the air enters into the cylinder, at the time of return stroke all the valves are closed
- by this air inside the cylinder is compressed by the piston, the compressed air gets high heated this is done at the piston is in an upward motion and at that
- time the fuel injection valve is opened by this fuel is pumped to the cylinder (the amount of fuel depends on the load)
- This fuel and high-temperature air combines and gets ignite this helps to burn the fuel which enters into the cylinder.
- In this fuel, the valve is closed after the supply of fuel to the cylinder due to the expanding gases.
- After this, the piston used to move in a downward motion by this the energy produced by the fuel is used for work. the exhaust gases pass out by opening the exhaust valves when the piston moves completely bottom of the cylinder.
A big diesel engine with the truck depicted in the contour lines
From many years this is used in Ships, locomotive trucks, Submarines, heavy vehicle.
This has better fuel economy over gasoline.
They produce more torque.
This has the highest thermal efficiency.
In this, there is no need of spark plug.
It has a higher compression ratio and vibration levels due to this quality they were bigger and heavier made.
It produces more noise than chain and belt system.
It offers better mileage.
Required maintenance is more.
In most of the cases retrofitting is not possible.
There are high emissions.
At highways, performance is good.
Different Types of Diesel Engines:
In Diesel Engine, there are two types they are Two strokes Diesel Engine and Four strokes Diesel Engines.
Two Stroke Diesel Engine:
- In this cylinder, the complete cycle is done in two strokes. It appears to be superior in cylinder size and speed.
- It has greater mechanical efficiency. this type of cylinder required an auxiliary air pump, and ports are used in it.
- To pre-compress, the air the blowers are used.
- This type is rarely used due to the low fuel efficiency is obtained.
Four Stroke Diesel Engine:
- It completes the cycle in four strokes which is Intake, Compression, Power, Exhaust.
- This is highly used due to the production of torque is more than two-stroke. Due to more fuel efficiency, this is highly used,
- This type of engines is more in weight than a two-stroke.
- This has valves in it, and complicated design than a two-stroke.
- In this, the remaining mixture is present in the combustion chamber itself.
- It emits less pollution than a two-stroke.
