Patent ID: 7661416

Claim:
A working-gas-circulation-type engine in which oxygen, a fuel that generates water vapor through combustion, and a working gas higher in ratio of specific heats than water vapor are supplied to a combustion chamber, the fuel is burnt in the combustion chamber so as to expand the working gas and thus output power, and the working gas contained in a post-combustion gas exhausted from the combustion chamber is resupplied to the combustion chamber through a circulation passage, comprising: a first condenser section provided in the circulation passage and adapted to condense water vapor contained in a circulation gas which is a gas flowing through the circulation passage to yield condensed water, through heat exchange of the circulation gas with the ambient air, thereby separating, from the circulation gas, water vapor which has been condensed into condensed water through the heat exchange; and a second condenser section provided in the circulation passage and adapted to condense water vapor contained in the circulation gas so as to yield condensed water, by means of cooling the circulation gas through utilization of latent heat of vaporization of condensed water which has been condensed in the first condenser section, thereby separating, from the circulation gas, the water vapor which has been condensed into condensed water through the utilization of latent heat of vaporization.