Experimental Investigation into the Performance of PEMFCs with Three Different Hydrogen Recirculation Schemes

Hydrogen recirculation systems (HRSs) are vital components of proton exchange membrane fuel cells (PEMFCs), and it is necessary to investigate different HRS schemes to meet the needs of high-power PEMFCs. PEMFCs are developing in the direction of low cost, high power, wide working conditions, low noise, compact structure, etc. Currently, it is difficult for hydrogen recirculation pumps (HRPs) to meet the flow requirements of high-power PEMFCs. HRPs inevitably have high parasitic energy consumption, loud noise output, high cost, easy leakage, and high failure rates. Therefore, it is necessary to study different HRS schemes to develop a better solution for high-power PEMFCs. In this study, the functional prototype of a piping and instrumentation diagram (P&ID) based on three HRSs of HRPs was designed, and a functional prototype was built. Working according to the analysis and comparison of PEMFC performance test data, we find that the net power trend of PEMFC systems using three different HRS technology schemes is consistent. The ejector scheme and the combination scheme do not reduce the performance of PEMFCs and have advantages in different power ranges, such as 24 A, 48 A, and other small current points. The PEFMC system net power order is as follows: ejector scheme > HRP scheme > combination scheme. At about 120 A, the net power outputs of the three HRS schemes in the PEMFC system coincide. From around 180 A onwards, the PEMFC system power of the combined HRS scheme gradually dominates. At 320 A, the PEFMC system net power order is as follows: combined HRS scheme > HRP scheme > ejector scheme.