Operating strategy optimization by response surface analysis for durable operation of a heavy-duty fuel cell truck

A proton exchange membrane fuel cell (PEMFC) of heavy-duty truck is operated in very harsh conditions, but it requires more longevity than a passenger vehicle. Currently, the durability strategy of vehicular fuel cell is set up for passenger vehicles. This study is designed to establish durability strategy of heavy-duty fuel cell trucks by model based on response surface analysis. A physics-based model is developed to predict degradation of a PEMFC under truck operation mode. The model is then validated with 2000 h of 20-cell PEMFC stack experimental data operated under the truck operation mode, such as world harmonized vehicle cycle (WHVC) mode. Since the various operating variables are presented, a response surface method (RSM) selects the power output and degradation rate as object functions. Results show that operating temperature is the most significant variable, followed by inlet temperature of gases. As the operating temperature increases, the power output increases, but the degradation is accelerated. By contrast, increasing gas inlet temperature decreases power output and degradation rate. When the fuel cell truck is operated at high humidity, moderate cell temperatures, and moderate gas inlet temperatures, the power output is maximized with minimum voltage degradation. As determined by this study, the optimal operating conditions are anode and cathode relative humidity of 100%, a fuel cell temperature of 61 degrees C, and a gas inlet temperature of 57 degrees C.