柴油表征燃料在高浓度CO₂氛围下燃烧机理的分析

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.