增压比5的离心压气机设计

Design of a pressure ratio 5 centrifual compressor

采用叶轮+扩压器+排气蜗壳组合的数值摸拟(I+D+V)方式,针对一使用压比为5.0的离心压气机开展设计研究。研究表明,跨音速扩压器的设计研究与跨音速叶轮研究同样重要;跨音速扩压器进口喉道将经历2种不同的堵塞状态;低转速的堵塞状态决定低转速时压气机的流量范围,高转速的堵塞状态决定叶轮极限负荷,即压气机极限转速和压比。采用I+D+V方式获得的压气机特性图显示,设计点(压比5.0,流量2.0 m3/s)处于最高效区,级效率0.85,喘振裕度0.17以上。

The designing study on a pressure ratio 5 centrifugal compressor has been done by the IDV numerical simulation for the entire flow field included impeller,diffuser and volute of the compressor.It shows that the study on transonic diffuser is the same important as the impeller,and a transonic diffuser would be chocked two times when the speed is been increased.The first choke has an important effects on the region of compressor mass flow;and the second choke would determined the limited loadness of impeller,so as the limited pressure ratio and speed of compressor.The chart map was obtained by IDV numerical simulation,which shows that the design point is in the high efficiency region,and stage efficiency is 0.85 at design point（pressure ratio 5.0,mass flow 2.0 m^3/s）,and the surge margin is up to 0.17.