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利用快速压缩装置对直喷天然气发动机的燃烧效率进行了分析。在宽广的当量比范围内 ,分析了三种燃料喷射方式下和均匀混合气燃烧时的燃烧效率。结果表明 ,燃油喷射方式下的燃烧效率在 0 .2～ 0 .9当量比范围内均具有较高的数值并与喷射方式无关 ;在当量比小于 0 .2和大于 0 .9时 ,由于 CO的原因 ,使燃烧效率降低。均匀混合气燃烧时 ,燃烧效率在当量比大于 0 .7时较高 ,而当量比小于 0 .7时 ,由于很高的未燃甲烷的生成使燃烧效率损失较大。燃料喷射燃烧与均匀混合气燃烧相比 ,维持高燃烧效率的当量比范围宽。因未燃甲烷的生成而造成的燃烧效率的损失与喷油时刻无关 ,因 CO造成的燃烧效率的损失随喷油滞后而增加
The combustion efficiency of direct injection natural gas engine was analyzed by rapid compression device. In a wide range of equivalence ratio, the combustion efficiency of three fuel injection modes and homogeneous mixture combustion was analyzed. The results show that the combustion efficiency in the fuel injection mode has a higher value in the range of 0.2-2.9 equivalent ratio and has nothing to do with the injection mode; when the equivalence ratio is less than 0.2 and greater than 0.9, the CO The reason for reducing the combustion efficiency. In the case of homogeneous mixture combustion, the combustion efficiency is higher when the equivalence ratio is larger than 0.7, and when the equivalence ratio is smaller than 0.7, the combustion efficiency is greatly lost due to the generation of very high unburned methane. Fuel injection combustion provides a wide range of equivalents over high combustion efficiency over homogeneous mixture combustion. The loss of combustion efficiency caused by the unburned methane generation has nothing to do with the fuel injection timing, and the loss of combustion efficiency due to CO increases with the fuel injection lag