变进气压力条件下发动机压缩空气制动过程分析.

Aiming at tlie problem that tlie energy recovery effect of hybrid pneumatic engine based on single stage energy storage system decreased witli the increase of tlie pressure of tlie air tank，double stage energy storage system was used into hybrid pneumatic engine，the view-point that the COP (coefficient of performance) could be improved by changing the inlet pressure was drawn preliminary. Based on the theory of variable mass thermodynamics，a mathematical model of compressed air circulation which was verified by testbed was established. Through the steady state simulation of the model，the influence of inlet pressure and air tank pressure on compressing braking process were obtained. The results indicate that the change of inlet pressure and the air tank pressure afect the quality of the recycled compressed air per circulation linearly. the ratio of air tank pressure and inlet pressure is a key factor affecting the COP which will decrease when the ratio increases. [ABSTRACT FROM AUTHOR]