一、前言回顾过去五年间船用柴油机的动向,在降低油耗方面取得成效的超长行程二冲程柴油机产量大幅度增加。而四冲程中速机,尽管理论上具有较高的推进总效率的明显优点,但因其缸数多、维修保养费时,以及整机性能对燃油特性和运转条件的变化较敏感等原因,故市场对其需求曼趋向减少。为此,西德MAN公司同日本专利引进方——三菱重工与川崎重工一起,着手研制兼备二冲程低速机与四冲程中速 I. Preface Recalling the trends of marine diesel engines in the past five years, the output of long-stroke two-stroke diesel engines that have achieved remarkable results in reducing fuel consumption has increased substantially. The four-stroke medium-speed machine, although theoretically have a significant advantage of the overall efficiency of the propulsion, but because of its large number of cylinders, maintenance costs, as well as the performance of the whole machine is more sensitive to changes in fuel characteristics and operating conditions and other reasons Market demand for its Mann reduced. To this end, West Germany MAN companies with the Japanese patent inflow - Mitsubishi Heavy Industries and Kawasaki Heavy Industries together to start the development of both two-stroke low-speed machines and four-stroke medium speed