燃料电池汽车用涡轮机叶轮设计及性能预测

Design and Performance Prediction of Turbine Impellers for Fuel Cell Vehicles

相较于传统内燃机,质子交换膜燃料电池的尾气具有低温、中压的特性.为了回收更多的能量,需对涡轮机进行全新的设计.基于燃料电池尾气特性,确定涡轮机叶轮设计目标,提出一种基于控制方程的叶轮出口设计方法,该方法能有效降低对经验参数的依赖且可避免计算的反复迭代.并通过数值模拟分析几何参数对叶轮气动性能的影响.结果表明,选择小的负攻角和小的出口安装角,同时采用入口后倾型叶轮有利于提高叶轮效率和膨胀比.

Compared with the traditional internal combustion engine,the exhaust gas of polymer electrolyte membrane fuel cell has the characteristics of low-temperature and medium-pressure.In order to recover more energy,the turbine must be designed to match fuel cell systems.Based on the characteristics of fuel cell exhaust gas,the design objective of turbine impeller is determined.A governing equation-based design method of impeller outlet is proposed.This method effectively reduces the dependence on empirical parameters and avoids the repeated iterations of calculation.The influence of geometric parameters on the aerodynamic performance of the impeller is then analyzed by numerical simulation.Results show that a smaller negative incidence,a smaller exit installation angle and the application of inlet backward-inclined blade are beneficial to increase the efficiency and expansion ratio of impellers.