To improve economic efficiency by effectively utilizing exhaust heat of a power generation system using a fuel cell and internal combustion engine.
This hybrid system S1 is structured by combining a natural refrigerant heat pump system 1 provided with a power generation mechanism, an SOFC power generation system 2, an absorption refrigerator 3, and a hot water storage unit 4. Combustion exhaust gas EG of the SOFC power generation system 2 is introduced to a first heat exchanger 14a of the natural refrigerant heat pump system 1, and a natural refrigerant is heated. Thereby, the natural refrigerant is in a supercritical state, and is introduced to an expansion turbine 15. The natural refrigerant is insulated and expanded at the expansion turbine 15, and pressure energy at that time is converted into torque. The torque is given to a power generator 51 through a rotary shaft 50, and AC power is generated.
Takao Ito
Jiro Higuchi