Diesel Engine

Diesel Engine is mainly worked on below strokes.

 01)Suction Stroke:-

In this stroke,the piston moves down from the top dead centre.As a result,inlet valve opens and air is drawn into the cylinder.After sufficient quantity of air with pressure is drawn,suction valve closes at the end of the stroke.The exhaust valve remains closed during this stroke.

 02)Compression Stroke:-

In this stroke,piston moves up from the bottom dead centre.During this stroke both inlet and exhaust valve are closed.The air drawn into the cylinder during suction stroke,is entrapped inside the cylinder and compressed due to upward movement of the piston.The fuel is injected into the hot compressed air where it starts burning,maintaining the pressure constant.When the piston moves to its top dead centre,the supply of fuel is cut-off.

 03) Power Stroke:-

In this stroke,both inlet and exhaust valve remain closed.The hot gases (which are produced due to ignition of fuel during compression stroke) and compressed air,now expand adiabatically,in the cylinder pushing the piston down and hence work is done.At the end of stroke,the piston finally reaches the bottom dead centre.

 04)Exhaust Stroke:-

In this stroke,the piston again moves upward.The exhaust valve opens,while inlet and fuel valve are closed.A greater part of the burnt fuel gases escape due to their own expansion.The upward movement of the piston pushes the remaining gases out through the open exhaust valve.Only a small quantity of exhaust gases stay in the combustion chamber.At the end of exhaust stroke,the exhaust valve closes and the cycle is thus completed