Patent ID: 8393551
Filing Date: 2013-03-12
Classification: B60H,B60K,B60W,H01M,Y02E,Y02T

Abstract:
1. A method of operating a coolant system for a vehicle having a fuel cell stack and a battery pack, the method comprising the steps of: (a) detecting a fuel cell stack warm up condition, the warm up condition being when the fuel cell stack is below a predetermined temperature range and is warming up; (b) if the fuel cell stack warm up condition is detected, activating a pump and a cabin coolant heater upstream from a heater core, which is located in a HVAC module, and directing a coolant flowing through the cabin coolant heater, through the heater core and through a fuel cell stack to thereby warm the fuel cell stack; (c) if the fuel cell stack warm up condition is detected, adjusting a blower to minimize an air flow in the HVAC module; (d) detecting a mountain grade descent condition, the mountain grade descent condition including at least that the vehicle is traveling downhill; (e) detecting a battery limit condition, the battery limit condition including the battery pack reaching an upper limit; (f) if the mountain grade descent condition and the battery limit condition are detected, activating the cabin coolant heater, which is a part of a cabin heating branch that directs a coolant through the heater core in the HVAC module, to thereby accomplish an electric load shed; and (g) if the mountain grade descent condition and the battery limit condition are detected, activating a fuel cell coolant heater to thereby increase the electric load shed.