US 8,007,946 B2 · Fuel cell system warm-up strategy with reduced efficiency losses

Abstract

A method for quickly and efficiently heating a fuel cell stack at system start-up. The method uses and prioritizes various stack heat sources based on their efficiency to heat the stack. A thermal set-point for heating the stack to the desired temperature is determined based on the ambient temperature and, the stack cooling fluid temperature. The set-point is then compared-to the stack heating provided by the heat sources that are operating through normal system start-up operation. If more heat is necessary to reach the set-point, the method may first charge a system battery using stack power where the load causes the fuel cell stack to heat up. If additional heating is still required, the method may then turn on a cooling fluid heater, then flow a small amount of hydrogen into the cathode inlet stream to provide combustion, and then increase the compressor load as needed.

Claims19

Dependent claims

A method for heating a fuel cell stack in a fuel cell system, said method comprising:

determining a heat set-point for heating the stack to a desired temperature;
determining whether current heat sources will heat the stack to the desired temperature;
and
using and prioritizing additional stack heating from the heat sources based on a heating efficiency of the sources.

1 more element

Dependencies are inferred from the claim text.

Fuel cell system warm-up strategy with reduced efficiency losses

Life of this patent

Fuel cell system warm-up strategy with reduced efficiency losses

Life of this patent

Abstract

Claims19