中文摘要：

内燃兰金循环采用氧气代替空气作为氧化剂规避氮氧化物排放,并通过在燃烧过程中喷入经废气加热的高温水增加作功工质,提高热效率. 基于自主开发的试验系统,研究不同点火时刻下的燃烧特性.试验结果表明,喷水能在有效控制燃烧速率的同时增加缸内作功工质,提高指示功和热效率. 通过增加燃油供给量等其他方法加快燃烧反应速率,同时推迟点火时刻,可在保证上止点缸内温度的同时降低压缩负功的影响,有利于进一步提高循环热效率.

英文摘要：

The emission of NOx is eliminated by using oxygen instead of air as oxidant in an internal combustion Rankinecycle（ICRC）engine.Water heated through exhaust gas is injected into the cylinder during the combustion and thermalefficiency is improved due to the increase of working fluid mass.In this paper,the combustion characteristics of a selfdevelopedICRC engine under various ignition timings were investigated.The results show that the combustion rate wascontrolled and the mass of the working fluid increased because of water injection.Moreover,work and thermal efficiencywere improved.The increase of combustion rate and the delay of ignition timing would lead to less compressionwork and suitable in-cylinder temperature.Hence,higher thermal efficiency can be achieved.