Experimental study on cold start strategy of high-power fuel cell system

With the gradual popularisation of clean energy, proton exchange membrane fuel cells (PEMFCs) have received widespread attention as a good way to apply hydrogen energy. Freezing during start-up of fuel cells in low-temperature environment can cause a series of problems, such as clogging of porous electrodes, obstruction of reactant gas transport, etc. leading to the failure of fuel cell start. Therefore, it is of great research significance to improve the stability and speed of cold start of proton PEMFC without heat source assistance. However, at present, most experimental research on cold start of fuel cells is focused on single cell or low-power stack. In this study, we will conduct start experiments at -5°C~-25°C based on a 130 kW fuel cell power system. The results showed that with the current loading slope 3A/s, the cooling water pump speed 3,000 rpm, the minimum time for automatic purging 50 s, the maximum time for purging 500 s, the impedance real part threshold for purging 750 mΩ, and a manual purge of the air and hydrogen circuits performed before starting, the system used in the study can successfully start at -25°C and then run to a stable operating point.