Freeze start drive cycle simulation of a fuel cell powertrain with a two-phase stack model and exergy analysis for thermal management improvement

•A freeze start drive cycle of a FCV powertrain is done with a two phase stack model.•Exergy sankey is used to show exergy loss distribution during entire drive cycle.•Inefficient energy consumption is mainly in the city stage after the freeze start.•Optimization directions like split cooling and power demand threshold are suggested.•Reaching optimal temperature for water drainage by lowering humidification proposed.