Automated cold storage protection for a fuel cell system

摘要

A system and method for selectively determining whether a freeze purge should be performed at shut-down of a fuel cell stack. The method includes identifying that the vehicle has been keyed off and then determining whether a stack membrane humidification value is less than a predetermined humidification value that identifies the humidification of membranes in fuel cells in the fuel cell stack. If the stack membrane humidification value is not less than the predetermined humidification value, then the method determines if the ambient temperature is below a predetermined ambient temperature, and if so, performs the freeze purge. If the ambient temperature is not below the predetermined ambient temperature, then the method performs a short non-freeze purge of the flow channels in the fuel cell stack. The method determines a wake-up time for a controller for a next time to determine whether a freeze purge should be performed.

主权项

1. A method for determining if and when to perform a freeze purge of flow channels in a fuel cell stack on a vehicle, said method comprising:
identifying that the vehicle has been keyed off; determining whether a stack membrane humidification value is less than a predetermined humidification value that identifies the humidification of membranes in fuel cells in the fuel cell stack; determining if an ambient temperature is less than a predetermined ambient temperature if the membrane humidification value is not less than the predetermined humidification value; performing a short non-freeze purge of the flow channels in the fuel cell stack if the ambient temperature is not less than the predetermined ambient temperature; determining a wake-up time for a system controller based on a wake-up temperature for a next time to determine whether a freeze purge should be performed; causing the controller to go into a sleep mode for the wake-up time after the wake-up time has been determined; determining whether the wake-up temperature is less than a predetermined freeze-purge temperature when the controller wakes up after being put in the sleep mode and the wake-up time has elapsed; determining a new wake-up time for the system controller based on the wake-up temperature if the freeze-purge temperature is not less than the wake-up temperature; causing a vehicle auto-start if the freeze-purge temperature is less than the wake-up temperature; performing a stack warm-up process after the vehicle auto-start to increase the temperature of the stack to a predetermined stack temperature; and performing the freeze purge after the fuel cell stack has been increased to the predetermined stack temperature.