(JP7029589-A)      The control method incorporates a plate type modifier (9) enclosed inside a pressure receptacle (24) and a fuel battery (FC). A fuel gas is supplied to an anode (3) of the fuel battery from a quality room (a) of the plate type modifier. Anode exit gas discharged from the anode is introduced into a combustion chamber (9b) of the plate type modifier. The combustion exhaust gas discharged from this chamber is supplied to a cathode (2) of the fuel battery.    The pressure of the cathode gas is kept constant. A branched line (12) connects an air supply line (4) to the cathode. The air supply line supplies air (A) to the combustion chamber. The pressure anode of the exit gas and air in the combustion chamber is made equal to the pressure of the gas inside the quality room. The pressure inside the combustion chamber and pressure receptacle are made almost equal by introducing air from the supply line into the pressure receptacle through an opening part (39).    ADVANTAGE -   Avoids explosion even if there is leakage of fuel.    (US5397656-A)      The method is for controlling a differential pressure of a plate reformer installed in a fuel cell power generation system, a raw material gas being reformed to a fuel gas in a reforming chamber of the plate reformer. The fuel gas is fed to an anode of a fuel cell, an anode exhaust gas from the anode is fed to a combustion chamber of the plate reformer, and a combustion exhaust gas from the combustion chamber is fed to a cathode of the fuel cell together with an air.    The method involves placing the plate reformer in a pressure vessel, maintaining a pressure of a cathode exhaust gas to a constant value, and feeding part of the air to be fed to the cathode and the anode exhaust gas into the combustion chamber to make a pressure of the air and that of the anode exhaust gas the same so as to make a pressure of the reforming chamber and that of the combustion chamber the same. A branch line for feeding the air into the combustion chamber is provided. An opening is formed on the branch line to allow the air to enter the pressure vessel so as to make the pressure of the reforming chamber, that of the combustion chamber and that of the pressure vessel the same.    ADVANTAGE -   Allows easy control of differential pressure of plate reformer as well as differential pressure between anode and cathode of fuel cell at same time.