不同海拔高度下柴油机低温起动性能试验研究

Experimental study on cold starting performance of diesel engine at different altitudes

以某重型电控高压共轨柴油机为研究对象,利用高海拔环境模拟试验台,开展在不同海拔高度环境下柴油机低温起动性能试验,对比不同海拔高度下柴油机起动性能及燃烧差异,研究高原低温环境对柴油机起动性能的影响。试验结果表明:相同低温环境下,随海拔高度升高,柴油机起动需要的循环数增加,起动时间变长;高海拔环境下,柴油机起动第一个循环,缸内未有明显燃烧迹象,低温起动前期缸内双峰燃烧比例增加;随着海拔高度升高,缸内燃烧始点逐步靠近压缩上止点位置。

In order to study the effect of cold starting performance of diesel engine,a heavy-duty electrically controlled high pressure common rail diesel engine is tested under the same low temperature and different altitudes by using a simulated high-altitude environmental testbench.The starting performance and combustion difference of the diesel engine at different elevations are compared.The results show that the number of cycles needed to reach the end mark of starting increases and the starting time is longer with the increase of altitude in the same temperature.At high altitude,there is no obvious burning sign in the cylinder for the first cycle of starting process,and the ratio of two peak combustion in the cylinder increases before starting at low altitude.The position corresponding to the starting point of combustion in the cylinder gradually approaches the compression top dead center with the elevation increasing.