To suppress soot and the like to stick on an inner wall of a combustion chamber, and reduce the frequency of maintenance inspection by supplying supporting gas having much hydrogen component as a supporting material from supporting gas supplying means to a combustion chamber, in the case where pre-mixture in which fuel and gas including oxygen for combustion are mix with each other beforehand is filled to a combustion chamber.
A first gas supply passage 5 is connected to a combustion chamber 3 of a premixed compression self-ignition engine, fuel (town gas) is supplied from a fuel supplying part 6 arranged on the way thereof, mixture of fuel and air is supplied and filled to the combustion chamber 3 through an intake valve V1. An exhaust gas passage 7 is connected to the combustion chamber 3, exhaust gas in the combustion chamber 3 is discharged through an exhaust valve V2. In this case, a second gas supplying passage 8 for supplying supporting gas is connected to the first gas supplying passage 5, and town gas (methane gas) is supplied to a second gas supplying passage 8 by a reforming device 9, serving reformed gas which is reformed by steam from a steam generating and supplying mechanism 7a as supporting gas.
NISHIGAKI MASASHI
NAKAMURA YUJI
