162hr强化道路振动工况实验下车载燃料电池电堆的氢气利用率和效率的变化

Experimental investigation of thesteady－state efficiency of fuel cell stack under strengthened road vibratingcondition

Yongping Hou

Dong Hao

Caoyuan Shen

Zhongying Shao

Abstract

The steady－stateefficiency of the fuel cell stack is experimentally investigated in terms ofsteady－state hydrogen utilization， actual efficiency and maximum efficiencypoint through a 162 h strengthenedvibration test in this paper， in order to analyse the steady－stateperformance of the fuel cell stack under long－term vibrating condition onstrengthened roads． The load spectra applied in the test are simulated by theacceleration signals of the fuel cell stack， which are previously measured in avehicle vibration test． The load signals of the vehicle vibration test areiterated through a road simulator from vehicle acceleration signals which areoriginally sampled in the strengthened road of the ground prove． The test results show that the steady－statehydrogen utilization of the stack decreases by 30．7％ during the test． The maximum drop of steady－state actualefficiency is 21．0％． Additionally， themaximum efficiency point of the stack declines by 5．4％， while the correspondingcurrent experiences an increment of 47．2 A． From the results it can beconcluded that the strengthened road vibration exerts a significant influenceon the steady－state performance of the fuel cell stack， which cannot and shouldnot be ignored during the research．

Fig． 1 e  Variation of actual hydrogen consumption during the strengthened vibration  test．

Fig． 2 e  Variation of hydrogen utilization during the strengthened vibration test．

Fig． 3 e  Variation of hydrogen utilization at 5 different current levels during the  test．

Table 1 e  Decline values and rates of hydrogen utilization

Fig． 4 e  Variation of actual efficiency during the strengthened vibration test．

Fig． 5 e  Differences of actual efficiency before and after the strengthened vibration．

Table 2 e  Parameters of maximum efficiency points at different vibration duration．

Fig． 6 e  Variation of maximum efficiency point during the strengthened vibration test．

Fig． 7 e  Corresponding current of maximum efficiency point during the strengthened  vibration test．

Conclusion

The following  conclusions can be obtained through the analysis of this paper：

（1） The  strengthened road vibration exerts a significant influence on the steady－state  hydrogen utilization of fuel cell stack． A fluctuating variation of hydrogen  utilization with an obvious downward trend is observed during the test， which  is most likely caused by the hydrogen crossover rate rises due to  strengthened vibration and the emergence of pinholes on proton exchange  membrane． Compared with performance before the vibration， the hydrogen  utilization descends dramatically and the maximum decline is 30．7％ with the  corresponding current of 5．4 A．

（2） During the  strengthened vibration test， the actual efficiency of stack experiences a  fluctuating variation with an obvious downward trend． Compared with performance  before the vibration， the actual efficiency descends significantly and the  maximum decline is 21．0％ with the corresponding current of 4．8 A． The maximum  efficiency point of the stack declines by 5．4％， while the corresponding  current experiences an increment of 47．2 A．

（3） From the  analysis in this paper， it can be concluded that the strengthened road vibration  exerts a significant influence on the steady－state performance of the fuel  cell stack， which cannot and should not be ignored during the research． As  this paper is just a preliminary analysis of the test results， the influence of  the strengthened road vibration on the internal components or materials of FC  stack requires further investigation．

和150hr强化道路振动工况实验下车载燃料电池电堆的不同电流下各极化损失的变化类似过程获得的数据，分成两个部分来进行描述。