改善气缸内直喷天然气发动机燃烧和排气特性的研究

• 作 者: 後藤雄一 佐藤由雄 蒋修治
• 出 处: 国外内燃机
• 发表日期: 2002年04期
• 关键词: 气体燃料发动机 天然气发动机 低负荷工况 缸内直喷 进气 发动机燃烧 部分负荷工况 废气再循环 直喷式 泵气损失

试制了配有新开发天然气喷射器的天然气直喷式试验机。在部分负荷时的THC和高负荷时的NO_x排放高是直喷式天然气发动机存在的问题。对利用进气节流减少THC和改善燃烧,以及通过EGR(废气再循环)降低NO_x进行了探讨。得出结果如下:(1)在中、低负荷工况利用进气节流可改善燃烧,在低负荷工况尽管节流会产生泵气损失,但仍可提高热效率,此工况的THC排放大大降低;(2)在高负荷工况适当的EGR可大大降低NO_x,且燃烧不会恶化;(3)在部分负荷工况同时采用进气节流和EGR,THC和NO_x排放都得以降低。

Trial production of natural gas direct injection testing machine equipped with newly developed natural gas injectors. THC at part load and high NO x emission at high load are problems with direct injection natural gas engines. The use of throttling to reduce THC and improve combustion, as well as to reduce NOx through EGR (exhaust gas recirculation) were discussed. The results are as follows: (1) In medium and low load conditions, the use of air intake throttling can improve combustion, while in low load conditions, although throttling will produce pumping losses, but still improve thermal efficiency, THC emissions (2) proper EGR at high load conditions can significantly reduce NO_x and combustion will not deteriorate; (3) intake throttle and EGR, THC and NO_x emissions are reduced at part load conditions.