丙烷发动机燃烧变动研究

Cycle to Cycle Variation of Combustion in a Spark Ignition Propane Gas Engine

测量了火花点火丙烷气体发动机在不同转速、涡流强度及混合比下的气缸压力，并对测量的气缸压力及由气缸压力求出的用曲轴转角表示的初期燃烧期间等进行了统计分析。试验结果表明，随着混合气变稀平均指示压力的变动迅速增大；转速相同时，平均指示压力的变动随着涡流比的增大而减小；在稀薄混合气条件下，随着初期燃烧期间平均值的增加平均指示压力的变动急剧上升。

In this paper,the pressure history of various conditions of engine speed,swirl ratio,equivalence ratio in the cylinder of a spark ignition propane gas engine was measured.The statistical analysis of pressure history in cylinder and the duration of early stage combustion in crank angle by one zone model from this pressure history was carried out.The results show that,if the mixture becomes lean,the fluctuation of indicated mean effective pressure increases very fast;when speed was fixed,average duration of early stage combustion decrease with swirl ratio increase;when average duration of early stage combustion increase under the conditions of lean mixture,the fluctuation of indicated mean effective pressure rapidly increases.