Petrol Engine | Difference Between Petrol Engine And Diesel Engine
Petrol engines are the types of heat engines in which internal combustion has spark ignition. it runs on relatively volatile fuels such as petrol. The Basic principle of the engine is the second law of thermodynamics.
A gasoline engine is an internal combustion engine with spark-ignition, designed to run on petrol.
Working Principle of petrol engine:
All the petrol engines are based on the principle of a Carnot cycle.
Construction of Petrol engine
it consists of:
- Spark plug
Working on petrol Engine
A typical four-stroke engine undergoes four cycles. These are:
In this stroke, the piston moves outward and the petrol air mixture from the carburetor is drawn into the cylinder from the inlet valve.
In this stroke, the piston is moved inward and the mixture is compressed adiabatically.
In this stroke, a spark from the spark plug burns the petrol air mixture due to which the temperature and pressure are increased. As a result, the gases expand adiabatically and move the piston outward. The piston moves the crankshaft, which in turn moves the flywheels.
In this stroke, the outlet valve opens and the gases are expelled out. The piston then again moves inwards. The cycle then begins again. Motorbikes have a one-cylinder engine but cars have four-cylinder engines on the same crankshaft.
The efficiency of Petrol Engine
The efficiency of petrol engines is only 25% to 30% due to friction and heat losses.
What is a diesel engine?
No spark plug is needed in a diesel engine. Diesel is sprayed into the cylinder under maximum compression, so the temperature rises to a maximum value. As a result, the fuel mixture gets ignited and produces gases of large volume. Due to this, the piston moves upward.
The efficiency of Diesel Engine
The efficiency of a diesel engine is 35% to 40%. The diesel engine is more efficient than a petrol engine
Difference between Petrol and Diesel Engine
|Diesel Engine||Petrol Engine|
|Diesel engines work on the Diesel cycle||Petrol Works on the basis of the Otto cycle|
|In a diesel engine ignition start with the help of hot, compressed air.||In a petrol engine Fuel is ignited with help of an electric spark|
|inside the cylinder, the fuel is mixed with air||Air and fuel are mixed in a carburetor|
|The diesel engine has a High compression ratio||The engine has a low compression ratio as compared to the diesel engine|
|The power production of diesel engines is high||The power production of a petrol engine is low relatively|
|diesel engines work with fuels that have low volatilities||Highly volatile fuels are used in this engine|
|These engines are used in heavy vehicles such as bus trucks etc.||These engines are used in light vehicles such as cars.|
|The fuel consumption of diesel engines is low||The fuel consumption is high|
|Its maintenance cost is high||Its maintenance cost is low|
|Its initial cost is high||Its initial cost is low comparatively|