高原环境条件下的柴油机起动过程试验研究

柴油机起动性能是柴油机的重要性能指标,高原环境对柴油机起动过程产生重要影响。为了研究高原环境对柴油机起动过程影响规律,针对某型12缸柴油机分别在高原和平原地区进行实车起动试验,对起动过程的气缸压力、上止点和瞬时转速进行测量。结果表明,高原环境下柴油机起动时间更长,转速波动更大,双峰燃烧比例更多。对起动过程进行逐循环燃烧分析,发现在高原环境以曲轴转角计的滞燃期更大,燃烧更加滞后;与此同时,在同等的转速水平下,在高原环境以时间计的滞燃期更长。

An Investigation on Starting Process Experiment of Diesel Engine in Altitude Environment

The starting performance of diesel engine is one of the main performance indexes.The altitude environment has an important influence on the starting process of diesel engine.A diesel engine with 12 cylinders was test to research the influence of altitude environment on diesel engine starting process in altitude environment and plain environment,and the cylinder pressure,top dead center,and instantaneous rotational speed were measured.The experimental results indicate that the starting time is longer,the fluctuation of rotational speed is greater,and the proportion of bimodal combustion is larger during starting in altitude environment.The combustion analysis of starting process indicates that the starting process in altitude environment has a longer combustion delay period calculated with crank degree,and the combustion in cylinder in altitude environment appears more delay than that in plain environment.The starting process in altitude environment has a longer combustion delay period calculated with time than that in plain environment at the same rotational speed.