developed the idea for the
diesel engine and obtained the German patent for it in 1892.
His goal was to create an engine with high efficiency.
Gasoline engines had been invented in 1876 and, especially at
that time, were not very efficient.
differences between the gasoline engine and the diesel engine
engine intakes a mixture of gas and air, compresses it and
ignites the mixture with a spark. A diesel engine takes in
just air, compresses it and then injects fuel into the
compressed air. The heat of the compressed air lights the
engine compresses at a ratio of 8:1 to 12:1, while a diesel
engine compresses at a ratio of 14:1 to as high as 25:1. The
higher compression ratio of the diesel engine leads to
engines generally use either carburetion, in which the air
and fuel is mixed long before the air enters the cylinder,
or port fuel injection, in which the fuel is injected just
prior to the intake stroke (outside the cylinder). Diesel
engines use direct fuel injection -- the diesel fuel is
injected directly into the cylinder.
animation shows the diesel cycle in action.
engines contain a glow plug of some sort (not shown in
this figure). When a diesel engine is cold, the compression
process may not raise the air to a high enough temperature to
ignite the fuel. The glow plug is an electrically heated wire
hat helps ignite the fuel when the engine is cold so that the
engine can start. According to Cley Brotherton, a Journeyman
heavy equipment technician:
in a modern engine are controlled by the ECM communicating
with an elaborate set of sensors measuring everything from
R.P.M. to engine coolant and oil temperatures and even engine
position (i.e. T.D.C.). Glow plugs are rarely used today on
larger engines. The ECM senses ambient air temperature and
retards the timing of the engine in cold weather so the
injector sprays the fuel at a later time. The air in the
cylinder is compressed more, creating more heat, which aids in