车用燃料电池引射器设计及测试评价方法研究

Research on the Design and Test Evaluation Methods of the Ejector for PEM Fuel Cell Vehicle

在研究开发车用燃料电池引射器时,湿氢流量监测困难、台架技术难度大、试验成本高,并且存在安全隐患和能源浪费问题。为此,在推导空气与氢气、空气与100%RH的氢在相同工作条件下的流量变化关系式的基础上,针对110 kW燃料电池,试制引射器进行空气和氢气测试,并结合数值仿真分析。结果发现:车用燃料电池引射器引射流体中水蒸气质量分数达到40%~50%;在相同工作条件下,空气与氢气的体积和质量流量分别等于其气体常数比值的平方根和比值倒数的平方根,其中空气与氢气的体积和质量流量之比分别为3.786和0.2641。工作、引射和混合流体质量流量的空气实测与仿真数据之间的平均相对误差分别为4.48%、4.54%和2.78%;空气实测数据经折算后与氢气测试数据相吻合,与湿氢的仿真数据平均偏差率分别为5.4%和6.11%;氢气测试数据经折算也与湿氢仿真数据相吻合。因此,空气测试数据经处理可以用于车用燃料电池引射器特性研究。

During the research and development of fuel cell ejectors for vehicles,it is difficult to monitor the wet hydrogen flow rate,with difficulty in the bench technology and high test cost,as well as safety risk and energy waste problems.To address the problems,based on the derivation of the flow rate relationship between air and hydrogen,air and 100% RH hydrogen under the same working conditions,an ejector for the 110 kW fuel cell is developed and tested by air and hydrogen,and numerical simulation analysis is conducted.It is found that the mass fraction of water vapor in the fluid ejected by the ejector reaches 40% to 50%.Under the same working conditions,the volume and mass flow rate of air and hydrogen is equal to the square root of the gas constant ratio and the square root of the reciprocal ratio,respectively.The ratio of volume and mass flow rate of air and hydrogen is 3.786 and 0.2641,respectively.The average relative error between the measured and simulated air flow rates for working,ejected,and mixed fluid mass flow rates is 4.48%,4.54%,and 2.78%,respectively.After conversion,the measured air data is consistent with the hydrogen test data,with an average deviation rate of 5.4% and 6.11% from the simulated wet hydrogen data,respectively.The hydrogen test data is also consistent with the wet hydrogen simulation data after conversion.Therefore,the processed air test data can be used for studying the characteristics of fuel cell ejectors for vehicles.