A reformer 34 includes three reforming reaction units 80, 82, and 84. These
reforming reaction units 80, 82, and 84 respectively include catalyst
layers 81, 83, and 85. A supply of crude fuel gas fed to the reformer 34
successively passes through the catalyst layers 81, 83, and 85 in this
sequence to be subjected to reforming reactions and converted to a
hydrogen-rich gaseous fuel. An air supply unit 90 feeds a supply of the
air to each catalyst layer. Oxidation reactions proceed in addition to the
reforming reactions in the catalyst layer which receives the supply of the
air. Heat produced by the oxidation reactions is utilized for the
reforming reactions. Temperature sensors 86, 87, and 88 respectively
measure the internal temperatures of the catalyst layers 81, 83, and 85.
The amount of the air fed to each catalyst layer is regulated, based on
the results of the measurement.
