FUEL REFORMING SYSTEM FOR VEHICLE WITH ENGINE MOUNTED THEREON

A fuel reforming system includes a reciprocating engine; a decomposer that decomposes a hydrocarbon fuel; and a hydrocarbon fuel supply device. The reciprocating engine includes an intake port, an exhaust port, and a third port that allows a cylinder and the decomposer to communicate and that is opened and closed by an on-off valve. The on-off valve opens in a stroke in which a combustion gas inside the cylinder is supplied to the decomposer with ascending of a piston. The on-off valve opens in a stroke in which a combustion gas, in which the carbon and the hydrogen gas has been removed, is introduced from the third port to the cylinder with descending of the piston. The hydrocarbon fuel supply device injects the hydrocarbon fuel into the third port between the on-off valve and the decomposer during a stroke in which the on-off valve is closed.