一、前言柴油机在原动机中热效率最高,因而大部分船舶都喜用柴油机作主机。这样,节省船舶燃料费用的根本问题就是提高柴油机的热效率与降低燃油消耗率 g_e。目前,二冲程低速机的 g_e 值已下降到120g/(ps·h)左右,四冲程中速机的 g_e 值已达 I. Foreword Diesel engines have the highest thermal efficiency in the prime mover, so most ships like to use diesel engines as their main engines. In this way, the fundamental issue of saving the cost of marine fuel is to increase the thermal efficiency of the diesel engine and reduce the fuel consumption rate g_e. At present, the g_e value of two-stroke low speed machine has dropped to about 120g / (ps · h), the g_e value of the four-stroke medium speed machine has reached