进油温度对生物柴油燃烧压力及循环变动的影响

在1台两缸直喷式柴油机上对比测试了生物柴油的燃烧特性,分析了进油温度对发动机峰值燃烧压力分布以及循环变动率的影响。结果表明,随着进油温度的增加,生物柴油发动机表现出如下燃烧特性:燃烧延迟,高负荷时延迟更明显;峰值燃烧压力降低,其循环分布向低值偏移;峰值燃烧压力分布最高值增加且其循环变化幅度明显降低,循环变动率降低,循环变动减弱;负荷或转速增加均导致循环变化幅度明显降低,循环变动减弱。研究结果证明,进油温度对燃用生物柴油的燃烧压力及其循环变动有重要影响,进油温度增加可以提高燃烧稳定程度,从而改善燃烧过程。

Influence of Biodiesel Temperature on Combustion Pressure and Cycle Variation

Combustion performances of biodiesel were tested and compared on a 2-cylinder DI diesel engine and influences of fuel temperature on peak combustion pressure and cycle variation rate were analyzed.The results show that the combustion delays and intensifies at high loads with the increase of fuel temperature.In addition,the peak combustion pressure decreases and its cycle distribution moves to the small value.Moreover,the maximum value of peak combustion pressure cycle distribution increases,the variation amplitude decreases obviously,the cycle variation rate decreases and the cycle variation weakens.The increase of load or speed will lead to the decrease of cycle variation amplitude and the cycle variation weakens.In the end,it is proved that the fuel temperature has the important influence on combustion pressure and cycle variation.The increase of fuel temperature may improve the combustion stability,and hence improves the combustion process.