How does a marine diesel engine work

Diesel engines are widely used in both road vehicles, and marine installations. But how do diesel engines work ?

Marine diesels, and diesel engines in general are a ‘compression ignition engine’.

Air is drawn into the cylinder, and then compressed.

This compression of the air is caused by the action of the piston in the cylinder, moving upwards.

At an optimal point in this compression of the air, fuel is injected into the cylinder.

The resultant fuel / air mixture, vaporises and becomes heated, due to the pressure in the cylinder.

The fuel / air mixture ignites, and the explosion, forces the piston down the cylinder.

As the piston is attached via a connecting rod, to the Crankshaft, the crankshaft turns.

Engine Efficiency

Approximately 40% of the fuels chemical energy, is converted into mechanical energy. This is the engine efficiency.

Turbocharging is a common method of increasing diesel engine performance.

What a turbocharger does, is increase the mass of air, entering a cylinder.