为了研究一种新型环形沸石分子筛在汽油机冷启动阶段的碳氢(HC)吸附特性,通过建立HC吸附器的直观模型和多孔介质模型,结合欧根方程确定2种模型的正确性;针对汽油机冷启动的200S内发动机转速由0提高至3000r·min-1的情况,对2种模型进行非稳态流场仿真,得到吸附器内速度场、密度场、4个监视点温度和吸附量的相关图形并进行分析。研究结果表明:新型吸附器内的压力场和密度场呈梯度分布;速度分布主要受入口质量流量的影响;温度随着内燃机燃烧逐渐呈现激烈上升趋势,最后达到稳定状态;吸附器能够吸附约81.5%的HC气体。
In order to study the absorption property of a new annular zeolite molecular sieve at engine cold start. The direct and the porous simulation models of HC absorber were established and analyzed by Ergun equation to judge the accuracy of them. The two models were used to simulate non-steady flow field, and the distribution of velocity field, density field, and changes of four monitor points' temperature and absorptive capability of the new equipment were got for analysis by changing the inlet boundary conditions continuously during the 200 s cold start phase with engine speed increasing from 0 to 3 000 r . min-1. The results show that the pressure and density field distribute in terraced shape; the distribution of velocity is mainly affected by the mass flow at entrance; the temperature rises gradually with combustion in internal combustion engine, and reaches a steady state finally; about 81.5 percent of HC gas can be absorbed into the absorber.