基于缸内直喷的甲醇汽油混合燃料HCCI燃烧排放特性研究

在缸内直喷发动机上研究甲醇汽油混合燃料的HCCI燃烧排放特性,分析了其非常规排放的性能。试验中选用汽油、M10(甲醇体积分数10%)、M20(甲醇体积分数20%)3种燃料,并通过FTIR方法测量甲醇及甲醛等非常规排放。研究结果表明:在汽油中添加甲醇可以有效拓展HCCI燃烧的高负荷范围,M20燃料的高负荷范围比汽油提高近9%,指示燃油消耗率比汽油高5%～10%,但指示能量消耗率比汽油低2%～6%。CO、THC、NOx等常规排放随甲醇添加比例的增加而降低,而甲醇和甲醛等非常规排放随甲醇添加比例的增加而增加,并随负荷增高呈先增加后减少的趋势。

Research on Emission Characteristics of Methanol-Gasoline Blend Direct Injection HCCI Combustion

The effect of methanol-gasoline blended fuel on emission characteristics of homogeneous charge compression ignition(HCCI) combustion was investigated in a direct injection engine fueled with three kinds of fuels,pure gasoline,M10 and M20 respectively.The unregulated emissions were measured using Fourier transform infrared spectrometer(FTIR).Results show that addition of methanol extends the high load limit of HCCI combustion.For M20 it can be extended by 9% than that of gasoline,and the indicated specific fuel consumption(ISFC) is 5%～10% higher but the indicated specific energy consumption(ISEC) 2%～6% lower due to methanol low heat value and fast reaction speed.The regulated emissions,CO,THC and NOx decrease and the unburned methanol and formaldehyde emissions increase as methanol content adds,and firstly increase and then decrease as engine load rises.