中文摘要：

对二甲醚与液化石油气预混平面火焰中不同掺混比例下的甲醛生成、NOx的排放特性进行了实验研究．实验结果表明，固定燃料质量流量和当量比条件下，火焰中甲醛质量浓度随着二甲醚掺混比例的增加而增加，其峰值质量浓度为相同工况纯LPG燃烧时的2—5倍，表明混合燃料中的二甲醚仍然是甲醛产生的主要来源；尾气中的NOx质量浓度随二甲醚比例的增加而降低，但均不高于16．08mg／m3．控制二甲醚的完全氧化是二甲醚与液化石油气掺混燃烧中减少甲醛排放的关键途径．

英文摘要：

This paper investigated the emission characteristic of formaldehyde and NOx in DME/LPG premixed plane flame under different fuel proportions. The results show that the concentration of formaldehyde increases with the mass proportion of DME at the same fuel-air equivalence ratio and fuel mass. The concentration peak value of formal-dehyde in the mixed flame is 2--5 times larger than that of the pure LPG flame. The results also show that the source of formaldehyde is mainly the oxidation of dimethyl ether （DME） in the DME/LPG premixed combustion. The concentration of NOx declines with the increase of the proportions of DME. Its values are less than 16.08 mg/m3 under all the experimental conditions. Known from the experiments in this paper, complete combustion and oxidation of dimethyl ether （DME） is the key to controlling the emission of formaldehyde in DME/LPG fuel.