![]() ![]() ![]() In the 1930s, they slowly began to be used in a few automobiles. Use in locomotives, buses, trucks, heavy equipment, agricultural equipment and electricity generation plants followed later. Since the 1910s, they have been used in submarines and ships. ![]() They were originally used as a more efficient replacement for stationary steam engines. The combined cycle gas turbine (Brayton and Rankin cycle) is a combustion engine that is more efficient than a diesel engine, but it is, due to its mass and dimensions, unsuited for vehicles, watercraft, or aircraft.ĭiesel engines may be designed as either two-stroke or four-stroke cycles. Low-speed diesel engines (as used in ships and other applications where overall engine weight is relatively unimportant) can reach effective efficiencies of up to 55%. A small efficiency loss is also avoided compared with non-direct-injection gasoline engines since unburned fuel is not present during valve overlap and therefore no fuel goes directly from the intake/injection to the exhaust. The diesel engine has the highest thermal efficiency ( engine efficiency) of any practical internal or external combustion engine due to its very high expansion ratio and inherent lean burn which enables heat dissipation by the excess air. The torque a diesel engine produces is controlled by manipulating the air-fuel ratio (λ) instead of throttling the intake air, the diesel engine relies on altering the amount of fuel that is injected, and the air-fuel ratio is usually high. With the fuel being injected into the air just before combustion, the dispersion of the fuel is uneven this is called a heterogeneous air-fuel mixture. This increases the air temperature inside the cylinder to such a high degree that atomised diesel fuel injected into the combustion chamber ignites. Air is inducted into the chamber during the intake stroke, and compressed during the compression stroke. This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine ( gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas).ĭiesel engines work by compressing only air, or air plus residual combustion gases from the exhaust (known as exhaust gas recirculation (EGR)). The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression thus, the diesel engine is a so-called compression-ignition engine (CI engine). 1952 Shell Oil film showing the development of the diesel engine from 1877 ![]()
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