掺杂H2和CO2对二甲醚燃烧的耦合化学作用研究

Coupled Chemical Effects of Carbon Dioxide and Hydrogen Additions on Dimethyl Ether Flames

对掺杂H_2和CO_2的二甲醚预混火焰进行研究,分析H_2和CO_2的化学效应对二甲醚燃烧火焰温度、主要产物、中间产物和自由基的耦合影响。结果表明,在10%H_2条件下,CO_2浓度越高,其化学效应对温度下降,二甲醚消耗,乙炔、甲醛、乙醛及H生成的抑制作用越强,对O、OH生成的促进作用也越强;H_2的化学效应对温度升高和二甲醚燃烧的促进作用随CO_2浓度升高而增强,对H生成的促进作用随CO_2浓度升高而减弱,对O、OH、乙炔、甲醛及乙醛生成的促进作用与CO_2浓度无关。

Kinetic analysis about coupled chemical effects of CO2 and H2 additions on laminar premixed dimethyl etherflames is performed. The coupled chemical effects of CO2 and H2 addition are analyzed on aspects of temperature, majorspecies, intermediate stable species and radicals. The result shows that when H2 is added, the CO2 chemical effects, whichcan decrease the temperature, the DME oxidation, the production of C2H2, CH2O, CH3CHO and H radical but promote theproduction of O and OH radicals, would varies directly with the CO2 concentration. However, CO2 addition can strengthenthe H2 chemical effects on increasing the temperature and DME consumption, but mitigate the H2 chemical effects onreducing the H mole fraction. And the CO2 concentration did not have obvious influence on the H2 chemical effects onincreasing the production of O, OH, C2H2, CH2O and CH3CHO.