Precheck and cold start of fuel cell engine: A system-level experimental investigation

Cold-start is a challenging issue for proton exchange membrane (PEM) fuel cell engine due to the high-probability of freeze-out. Apart from the clog inside the channel, the freeze among components is equally critical especially in the system-level engine. Motivated by this, a precheck and fault diagnosis method is proposed, for the first time, to ensure the functional reliability of PEM fuel cell engine in cold climate. Based on a 40-kW stack, the proposed method includes three stages of precheck, preheat and self start-up, covering eight susceptible components within both air and hydrogen subsystems. Through the speed-and pressure-related detections, the alarm signals alert when not passing the threshold judgements. Experimental results validate the identifiability among multiple component-level faults and the fidelity of diagnostic in application. Moreover, during several months of investigations, the significance of the proposed method is further emphasized by the destructive and underlying damage without precheck. With the help of the proposed method, a successful start-up from -20 degrees C takes advantage of 48% chemical energy heating the fuel cell engine and maintaining steady operation for more than 5 mins. According to the Sankey map, 3.75% parasitic power indicates the functional reliability of tested engine. The conducted investigations reveal the freeze-out phenomenon other than fuel cell stack, giving a deeper insight into precheck and fault diagnosis issue with respect to fault type, influential component and improvement measurement.