柴油机工作时,燃料燃烧所产生的热量,只有约三分之一能够变成有用的功,而大部分热量不能被充分利用,这其中有一部分热量随排气管排出机外,而另一部分将传至柴油机机件,致使机件温度升高,特别是同燃烧气体直接接触的机件(活塞、缸套、气缸盖等)受热更为严重,瞬时温度可达2000℃左右。柴油机的正常工作温度一般为 When the diesel engine is operating, only about one third of the heat generated by the fuel combustion can turn into useful work, while most of the heat can not be fully utilized. Some of the heat is discharged outside the exhaust pipe while the other part Transmission to the diesel engine parts, resulting in mechanical temperature, especially with direct contact with the combustion gases (piston, cylinder liner, cylinder head, etc.) more serious heat, instantaneous temperature up to about 2000 ℃. The normal operating temperature of diesel engine is