车载燃料电池低比转速离心压气机设计

Low specific speed centrifugal compressors for automotive fuel cell systems

设计了普通高速（20000r·min^-1）电机驱动的车载燃料电池低比转速离心压气机。总结了压气机设计特点，并利用三维数值模拟计算（CFD）技术初步研究了压气机叶轮内部流场，得到了相应的特性曲线与主要气动参数分布。根据数值模拟分析，所设计的车载燃料电池低比转速离心压气机具有较高的效率和较宽广且平坦的工作特性，叶轮在设计转速下最高效率达83％，最高压比达1．6，流量范围在0．05～0．20kg·s^-1。所设计的低比转速离心压气机，能满足车载燃料电池空气系统对于压气机的要求，同时避免了采用高比转速离心压气机所需的超高速电机所带来的问题。

The air systems of automotive fuel cell engines can be improved by using low specific speed centrifugal compressors powered by electric motors with an ordinary high-speed of 20 000 r· min^-1. A three-dimensional computational fluid dynamics analysis was used to investigate the compressor impeller flow field to obtain the impeller characteristic curves and primary aerodynamic parameters. The results indicate that the designed low specific speed impeller has high efficiency with a wide operating range of 0. 05 - 0.20 kg ·s^-1, a highest efficiency of 83%, and a highest impeller pressure ratio of 1.6 at the design speed. Therefore, the low specific speed centrifugal compressor meets the requirements of air systems for automotive fuel cell engines and avoids the problems caused by super high-speed electric motors in high specific speed centrifugal compressors.