二甲醚HCCI发动机污染物排放的气相色谱试验研究

在对配有氢火焰离子化检测器的气相色谱仪的分离柱温、载气流速、气化室温度和检测器温度等工作条件进行优化的基础上,采用外标法,经色谱工作站绘制出甲醛和甲酸甲酯的工作标准曲线,继而对二甲醚均质压燃发动机的常规排放物、甲醛和甲酸甲酯排放进行了检测。试验结果表明,二甲醚均质压燃发动机可在较窄的工况范围内运转,其燃烧温度较低,排气温度仅在120～220℃的较低范围内变化,NOx和碳烟可达到零排放水平,随着负荷的增加,CO2排放增加,CO和HC的排放减少;甲醛和甲酸甲酯作为不完全燃烧产物存在于排气中,二者的排放量随着负荷或转速的增加而减少。

Experimental Research on Pollutant Emission from a DME HCCI Engine

Based on the optimization of column temperature, carrier gas flow rate, injection temperature, detector temperature for gas chromatograph with hydrogen flame ionization detector(FID), the workstation of chromatogram collected data and drew the working curve of formaldehyde and methyl formate by using external standard method. The conventional emission, formaldehyde and methyl formate were measured from a HCCI engine fuelled with dimethyl ether (DME). The results show that the DME HCCI engine can only operate in a narrow operation condition with lower combustion temperature. Exhaust temperatures change between 120～220℃. NOx and soot can achieve zero emission level. Moreover, with the increase of load, CO2 increases, CO and HC decrease. As intermediate products of incomplete combustion, formaldehyde and methyl formate exist in exhaust and decrease with the increase of engine speed or load.