【作者】 苏翔； 王晨旭； 李理光； 崔文一； 邓俊；

【Author】 Su Xiang;Wang Chenxu;Li Liguang;Cui Wenyi;Deng Jun;School of Automotive Studies,Tongji University;

【机构】 同济大学汽车学院；

【摘要】 氩气动力循环氢气机闭式运行下,少量渗入缸内的润滑油燃烧等原因会导致循环气中存在痕量CO₂累积。为探究CO₂累积对燃烧和爆燃特性影响,基于变比热比奥托循环热力学计算模型,研究了循环气中CO₂摩尔分数（CO₂在ArO₂-CO₂混合气中的摩尔比）对热力学循环效率、功率密度和滞燃期的影响。计算结果表明,随着CO₂摩尔分数增加,热力学循环效率和功率密度降低;当CO₂摩尔分数从0%增加至15%时,热力学循环效率从69.90%降低至61.33%,相对下降12.26%,同时,功率密度相对下降25.04%。CO₂摩尔分数增加也会显著延长滞燃期,有利于抑制爆燃倾向。结合增加压缩比和增加混合气中氩氧比的策略,可补偿CO₂累积对热效率和功率密度的降低。更多还原

【Abstract】 Trace CO₂ accumulates in the circulating gas due to the combustion of a small amount of lubricating oil that penetrates into the cylinder when the argon power cycle hydrogen engine runs in closed-loop operation.In order to investigate the effect of CO₂ accumulation on combustion and detonation characteristics,the effects of CO₂ mole fraction（mole fraction of CO₂ in Ar-O₂-CO₂ mixture）on thermal conversion efficiency,power density and ignition delay time were studied based on the Variable Kappa Otto cycle thermal calculation model.The results show that the thermal conversion efficiency and powerdensity decrease with the increase of CO₂ mole fraction.When the CO₂ mole fraction increases from 0% to 15%,the thermal conversion efficiency decreases from 69.90% to 61.33%,a relative decrease of 12.26%,and the powerdensity decreases by 25.04%.The increase of CO₂ mole fraction will also significantly prolong the ignition delay time,which is conducive to inhibiting the knocking tendency.Combined with the strategy of increasing the compression ratio and increasing the argon-oxygen ratio in the mixture,the reduction of thermal efficiency and power density caused by CO₂ accumulation can be compensated.更多还原