S1100柴油机满足非道路国Ⅲ排放要求的试验

Optimization of S1100 Diesel Engine to Meet Non-Road National Ⅲ Emission Standards

以S1100小功率非道路柴油机为研究对象,提出从机内和机外净化两方面对其进行排放控制方案优化并试验.机内净化从油、气混合和燃烧的"数量、时间、空间"关系分析,给出低排放燃烧过程的技术路线,通过进/排气道流道结构的优化提高气道的流量系数,增加进气量,增大过量空气系数使燃烧完善;通过供油提前角改变控制NOx排放值,通过燃烧室形状结构设计、控制压缩余隙等减少无效燃烧空间和优化喷油嘴喷油油束在燃烧室的空间分布,改善空间油、气混合均匀性,实现快速燃烧.优化燃烧过程使柴油机性能改善、排放减少,柴油机初次排放试验结果已低于国Ⅲ排放标准限值.用安装氧化催化器(DOC)的一体式净化消声器,进一步降低CO、HC和PM排放,整机的CO、HC+NOx和PM排放试验结果分别为0.38、5.63和0.41,g/(k W·h),所占第三阶段对应排放限值分数分别为6.91%,、75.07%,和68.33%,,使用有效寿命期内有较大的劣化余量,S1100柴油机能满足国Ⅲ排放标准的要求.

Emissions control measures from both in-cylinder combustion and after treatments were conducted on a small power non-road diesel engine S1100.For the in-cylinder combustion measures,a low emission technical routine was provided by analyzing the interactions of ＂quantity＂,＂time＂ and ＂space＂ of air,fuel and their mixing process.The combustion was improved with the more fresh charge and higher volumetric efficiency through optimizing intake and exhaust port structures.The NOx emission was reduced by retarding the start of injection timing.Fast burning was realized by optimizing the combustion chamber geometry, reducing the compression clearance and improving the fuel spray spatial distribution.Through the above optimizations of the combustion process,the engine-out emissions are shown to be lower than the National Ⅲ emission limits.In addition,CO,HC and PM emissions were further decreased by installing a muffler coupled with a DOC inside in the exhaust pipe.Finally,the specific emissions of CO,HC＋NOx and PM of the engine are0.38,5.63 and 0.41,g/（k W·h）respectively and takes the proportion of National Ⅲ emission limits of 6.91%,,75.07%, and68.33%, respectively.The engine test also shows that there is a larger deterioration margin during the life cycle period.This indicates that the S1100 diesel engine has already met the requirements of National Ⅲ emission standards.