Patent ID: 8202656

Claim:
A method of heating a fuel cell stack on startup, in a system comprising a fuel cell stack; an air supply for providing air to the stack; a fuel supply including a fuel reformer for providing reformate fuel to the stack; an afterburner which burns raw fuel or unused fuel in an anode exhaust stream, or both raw fuel and unused fuel in the anode exhaust stream, and which comprises a start burner; an afterburner heat exchanger for transferring heat from the afterburner to the air supply and the fuel supply; and a radiative heat exchanger for exchanging heat between the fuel cell stack and the air supply and the fuel supply primarily by radiation; wherein the air supply passes through the afterburner heat exchanger and then through the radiative heat exchanger in series, and wherein the fuel supply passes through the afterburner heat exchanger then through the radiative heat exchanger, the method comprising the steps of: (a) operating the start burner to heat the afterburner heat exchanger; (b) directing heated air from the afterburner heat exchanger to the radiative heat exchanger; and (c) heating the stack with the radiative heat exchanger substantially by radiative means, wherein the radiative heat exchanger has at least one major surface area directly exposed to the stack.