Fuel Delivery Details about Diesel Marine Aeronautical Engine

Fuel Delivery system
A vital component of all diesel engines is a mechanical or electronic goernor which regulates the idling speed and maximum speed of the engine by controlling the rate of fuel delivery. Unlike Otto-cycle engines,incoming air is not throttled and a diesel engine without a gonernor cannot have stable idling speed and can easily overspeed, resulting in its destruction . Mechanically governed fuel injection systems are driven by the engine's gear train.These systems use a conbination of springs and weights to control fuel delivery relative to both load and speed. Modern electronically controlled diesel engines control fuel delivery by use of an eletronic control module (EcM) or Electronic Control Unit.

The ECM/ECU receives an engine speed, as well as other operating parameters such as intake manifold pressure and fuel temperature, form a sensor and controls the amount of fuel and start of injection timing through actuators to maximise power and efficiency and minimise emisions. Contiolling the timing of the start of injection of fuel into the cylinder is a key to minimizing emissions, and maximizing fuel economy , of the engine. The timing measured in degress before TDC, the stat of injection, ot timing ,is said to be 10 deg. BTDC ..

Delaying srart of injection causes incomplete combustion, reduced fuel efficiency and an increse in exhaust smoke, containing a considerable amount of particulate matter and unburned hydrocarbons. Advancing the start of injection results in higher in-cylinder pressure and temperature, and higher efficiency , but also risults in elevated engine noise and increased oxides of nitroger emission due to higher combustion temperatures. Optimal timing will depend on the engine design as well its speed and load.