Patent ID: 7547333

Claim:
A fuel reforming system of a fuel cell system, comprising: a combustor comprising: a main combustion part adapted to perform premixed lean combustion; a sub-combustion part provided upstream of the main combustion part, the sub-combustion part being adapted to perform a first lean combustion; a fuel pre-vaporization part between the main combustion part and the sub-combustion part, the fuel pre-vaporization part adapted to pre-vaporize fuel; a main fuel injection valve adapted to supply liquid fuel to the fuel pre-vaporization part; and a sub-fuel injection valve adapted to supply fuel to the sub-combustion part; and a fuel reforming device provided downstream of the combustor, the fuel reforming device comprising: a fuel reformer adapted to generate hydrogen-rich gas by a steam reforming reaction of fuel and an oxidation reaction of fuel, wherein the fuel reforming system is adapted to, (a) subject, when the fuel cell system starts, predetermined amounts of fuel and air for generating heat required in the fuel pre-vaporization part to the first lean combustion in the sub-combustion part, (b) pre-vaporize fuel to be combusted in the main combustion part in the fuel pre-vaporization part by use of a first combustion gas generated by the first lean combustion in the sub-combustion part, (c) subject air and the pre-vaporized fuel obtained by the pre-vaporization in the fuel pre-vaporization part to a second lean combustion in the main combustion part, and (d) heat, with a second combustion gas generated by the second lean combustion in the main combustion part, the fuel reformer of the fuel reforming device.