重油和二甲醚复合燃料的燃烧及排放特性的研究

Combustion and Emission Charcteristics of Heavy Oil and Dimethyl Composite Fuel

在不改变YC6A220C玉柴发动机结构和参数的前提下,燃用120 c St纯重油、25%二甲醚和45%二甲醚复合燃料,将发动机的工况设定为1 200 r/min、1 400 r/min和1 600 r/min,负荷为20%,40%、60%、80%和100%进行对比。对燃料的燃烧和排放性能进行测定,试验结果表明:重油-二甲醚复合燃料相比纯重油,在燃烧性上有明显改善,缸压增大,放热率峰值提高,滞燃期缩短;随着复合燃料中二甲醚比重的增加,复合燃料的放热率进一步提高;在排放方面,复合燃料相比纯重油,污染物中的一氧化碳、碳氢化合物和烟度都有明显的下降,当复合燃料中二甲醚比重增加时,减排效果更加明显,其中一氧化碳减排最大达到57.6%;碳氢化合物达到76.84%;碳烟减排率为57.85%,而氮氧化物排量在低负荷时上升了28.87%。

Without changing the structure and parameters of YC6A220 C Yuchai engine, fueled with120 c St pure heavy oil,25% of dimethyl ether（DME） and 45% DME composite fuel, the operating condition of the engine is set to 1200 rpm, 1400 rpm and 1600 rpm and load is 20%,40%,60%,80% and 100%, the fuel combustion and emission performance were tested. The test results show that,compared to pure heavy oil, the combustion of the heavy oil-two DME composite fuel is improved significantly,the cylinder pressure increases,the peak heat release rate increases,the ignition delay period is shortened;with the increase in the proportion of two DME composite fuel,exothermic compound fuel rate further increased;in terms of emissions, composite fuel compared to pure heavy oil, pollutants in carbon monoxide,hydrocarbons and smoke are reduced,when the two ether compound fuel proportion increased,emission reduction effect is more obvious, carbon dioxide emission was reduced by 57.6% maximum;hydrocarbons emission was reduced by 76.84%;soot emission reduction rate was 57.85%,while nitrogen oxide emission in low load increased by 28.87%.