Abstract: A fuel cell power plant (9) includes a stack (10) of fuel cells, each including anodes (11), cathodes (12), coolant channels (13) and either (a) a coolant accumulator (60) and a pump (61) or (b) a condenser and cooler fan. During shutdown, electricity generated in the fuel cell in response to boil-off hydrogen gas (18) powers a controller (20), an air pump (52), which may increase air utilization to prevent cell voltages over 0.85 during shutdown, and either (a) the coolant pump or (b) the cooler fan. Operation of the fuel cell keeps it warm; circulating the warm coolant prevents freezing of the coolant and plumbing. The effluent of the cathodes and/or anodes is provided to a catalytic burner (48) to consume all hydrogen before exhaust to ambient. An HVAC in a compartment of a vehicle may operate using electricity from the fuel cell during boil-off.

Abstract: A fuel cell power plant (9) includes a stack (10) of fuel cells, each including anode (11), cathodes (12), coolant channels (13) and either (a) a coolant accumulator (60) and pump (61) or (b) a condenser and cooler fan. During shutdown, electricity generated in the fuel cell in response to boil-off hydrogen gas (18) powers a controller (20), an air pump (52), which may increase air utilization to prevent cell voltages over 0.85V during shutdown, and either (a) the coolant pump or (b) the cooler fan. Operation of the fuel cell keeps it warm; circulating the warm coolant prevents freezing of coolant and plumbing. The effluent of the cathodes and/or anodes is provided to a catalytic burner (48) to consume all hydrogen before exhaust to ambient. An HVAC in a compartment of a vehicle may operate using electricity from the fuel cell during boil-off.