Puristussytytysjärjestelmä

Puristussytytysjärjestelmä, often translated as compression ignition system, refers to the principle by which internal combustion engines, specifically diesel engines, initiate combustion. Unlike spark ignition engines that rely on an external electrical spark to ignite the fuel-air mixture, puristussytytysjärjestelmä utilizes the heat generated by the compression of air within the cylinder.

In a puristussytytysjärjestelmä, air is drawn into the cylinder during the intake stroke and then compressed to a very high pressure. This intense compression significantly raises the temperature of the air. Subsequently, fuel is injected directly into this hot, compressed air. The high temperature of the air causes the fuel to auto-ignite, or ignite spontaneously, without the need for a spark plug.

This process results in a more efficient combustion, particularly at lower engine speeds, and allows for higher compression ratios compared to spark ignition engines. The inherent design of puristussytytysjärjestelmä contributes to the characteristic torque of diesel engines. The primary components of such a system include the fuel injection system, which must be capable of delivering fuel under extremely high pressure at the precise moment of injection, and robust cylinder construction to withstand the high pressures and temperatures involved.