PEM-FC cold start simulation

Autoren

M. Bahr - Zentrum für Brennstoffzellen, Technik GmbH, M. Schmitz - TME, RWTH Aachen University

Zusammenfassung

For trouble-free and reliable operation of fuel cell vehicles, it is important to ensure that the vehicle can be started safely and quickly under all operating conditions. This applies in particular to cold starting. In this context, this paper presents investigations on the cold start capability of PEM fuel cells. For this purpose, a modular, real-time capable system simulation model was developed. For the modelling and validation, locally resolved measurements were performed with operation temperatures down to -20 °C.

Based on these measurements, a CFD model was created and an existing segmented 2D+1D fuel cell stack model was extended to include the formation of liquid water and its influence on cell performance. In addition, the validated temperature range of the stack model was extended to include the temperatures occurring during cold starts according to the measurements. Furthermore, the cold start capability of a membrane humidifier was investigated in a CFD model. The results and findings were subsequently incorporated into an existing balance-of-plant system model, which was extended to include liquid water and low temperatures. Both the 2D+1D fuel cell stack model and the findings of the CFD simulation regarding the membrane humidifier were integrated into the system model.