柴油表征燃料在高浓度CO2氛围下燃烧机理的分析

为研究高浓度CO₂在高温高压情况下对柴油燃烧特性的影响，提出了柴油表征燃料在CO₂/O₂氛围下的燃烧反应机理.通过量子化学计算了化学反应路径并对反应路径进行分析，最后进行柴油表征燃料燃烧的仿真.通过搭建定容燃烧弹试验台架和可视化系统进行试验与仿真分析，结果表明：在50% CO₂+50% O₂氛围下，对仿真与实验的火焰燃烧极限长度和火焰纵截面面积进行对比，最小误差分别为0.39%和0.64%，最大误差分别为8.54%和4.94%，说明此机理适用于高浓度CO₂氛围下柴油燃烧特性的研究；CO₂的化学效应在柴油表征燃料燃烧时具有促进作用，CO₂在2600 K时发生热解，热解产物CO与H自由基等发生反应可以生成着火促进剂·OH；柴油在50% CO₂+50% O₂、43% CO₂+57% O₂和35% CO₂+65% O₂氛围下的燃烧效率比空气氛围分别提高了28.2%、30.4%和33.3%.

Analysis of the combustion mechanism of diesel surrogate fuel under high-CO2 atmosphere

In order to study the effect of high concentration of CO₂ on the combustion characteristics of diesel under high temperature and high pressure, a combustion reaction mechanism of diesel fuel under CO₂/O₂ atmosphere is proposed. The chemical reaction paths are calculated and analyzed by quantum chemistry, and simulation of diesel fuel combustion is performed. Finally, a constant volume combustion test chamber is built and visualized. The experimental and simulation results show that in 50% CO₂ and 50% O₂ atmosphere, the minimum errors between the simulation and experimental results for the flame combustion maximum length and area of the flame longitudinal section are 0.39% and 0.64%, and maximum errors are 8.54% and 4.94%, respectively. It indicates that the proposed mechanism is suitable for the study of diesel combustion characteristics in a high-concentration CO₂ atmosphere. The chemical effect of CO₂ can promote the combustion of diesel fuel. CO₂ will undergo pyrolysis at 2600 K. The pyrolysis product CO can react with H free radicals to generate ignition promoter·OH. The combustion efficiency of diesel under 50% CO₂+50% O₂, 43% CO₂+57% O₂ and 35% CO₂+65% O₂ atmosphere is 28.2%, 30.4% and 33.3% higher than that of air atmosphere, respectively.