汽油/柴油双燃料高比例预混压燃燃烧与排放的试验

对汽油/柴油双燃料高比例预混燃烧(HPCC)模式的燃烧及排放特性进行了初步的试验研究.结果表明,通过改变柴油的喷射时刻、汽油比例,HPCC呈现出由多种燃烧模式组成的复合燃烧模式,可以实现极低的NOx和碳烟排放,并能保持较高的热效率.试验工况下,汽油比例为50%时,柴油喷油时刻在-58～-6,°CA ATDC时热效率较高,喷油时刻在-49,°CA ATDC和-16,°CA ATDC时分别出现碳烟和NOx排放峰值.进气压力影响HPCC着火滞燃期、燃烧反应速度和"失火"与"爆震"燃烧汽油比例限值,提高进气压力可以提高汽油比例,实现超低的NOx和碳烟排放,并降低HC排放,但CO排放有所升高.随着汽油比例的增加,NOx与碳烟排放降低,对于IMEP为0.5,MPa、汽油比例大于50%时,两者的原始排放分别低于0.4,g/(kW.h)、0.06,FSN,但HC和CO排放升高.

An Experimental Study on Combustion and Emissions of Gasoline/Diesel Dual Fuel HPCC

This study investigates the combustion and emissions of a gasoline/diesel dual fuel high premixed charge combustion(HPCC) engine.The results show that HPCC is a compound combustion model,which can achieve ultra low NOxand smoke emissions,and high-efficiency by varying the diesel SOI and gasoline to diesel fuel ratio.Thermal efficiency is high when the diesel SOI between-58,°CA ATDC and-6,°CA ATDC,and the highest emissions of smoke and NOxappear at-49,°CA ATDC and-16,°CA ATDC respectively at 50% of gasoline to diesel fuel ratio.Intake pressure influences the ignition delay,combustion rate and gasoline to diesel fuel ratios of misfire and knocking limit.Increasing in intake pressure can increase the gasoline to diesel fuel ratio and remarkably decreases NOx,smoke and HC,with the penalty of CO.At IMEP of 0.5,MPa and higher percentages of gasoline than 50%,NOx and smoke emissions are below 0.4,g/(kW.h)and 0.06,FSN respectively in the absence of after-treatment with penalty of HC and CO emissions.