两级增压系统参数对泵气损失影响的热力学分析  

Thermodynamic Analysis of the Effect of Two-Stage Turbocharging System Parameters on Pumping Losses

作　　者：冯浩[1] 郑尊清[1] 毛斌[1] 官维[2] 黄冠衍 尧命发[1] 

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072 [2]广西大学机械工程学院,南宁530004

出　　处：《内燃机工程》2016年第5期221-228,共8页Chinese Internal Combustion Engine Engineering

基　　金：国家"九七三"重点基础研究发展计划项目(2013CB228402)

摘　　要：建立了两级增压系统热力学模型,分别分析了压比分配、级间中冷、增压器效率和排气温度等参数对泵气损失的影响,并确定了不同参数下的最佳压比分配。研究结果表明:在高、低压级压气机入口温度和增压器效率均相同时,压比分配为1时可获得最低泵气损失;降低高压级压气机入口温度能明显降低泵气损失,最佳压比分配随高压级压气机入口温度的降低而增加;增压器总效率的提高能显著降低泵气损失,级间无中冷且增压器总效率一定的情况下,泵气损失随压气机效率的提高而减小;级间无中冷时,不同增压器效率对应的最佳压比分配存在突变,但此时泵气损失对压比分配变化不敏感;泵气损失随涡前温度的降低呈线性增加,这对新型燃烧方式的涡轮增压器设计和匹配提出更高的要求。A thermodynamic model was developed for two-stage turbocharging system to study the effect of different parameters, such as pressure ratio distribution （PRD）, inter-stage cooler, isentropic efficiency and exhaust gas temperature, on pumping losses, and optimized PRD was concluded for discrete parameter. Results show that minimum pumping losses can be reached at PRD of 1 when compressor inlet temperature and total efficiency of each stage turbocharger are equal, respectively. Lower inlet temperature for high pressure （HP） compressor contributes to lower pumping losses, and its corresponding optimized PRD is also higher. The increase of total isentropic efficiency can significantly reduce pumping losses, which will decrease further when compressor efficiency increases even if total efficiency is constant unless the HP compressor inlet temperature is not higher than the low pressure （LP） one. There is a step change in optimized PRD correspond to different turbocharger efficiency without inter-stage cooler, but in the meantime the pumping losses is not sensitive to the change of the PRD. Pumping losses will increase linearly with the decrease of exhaust gas temperature.

关 键 词：内燃机 两级增压 泵气损失 压比分配 级间中冷 增压器效率 

分 类 号：TK421.8[动力工程及工程热物理—动力机械及工程]