To prevent the decreasing of output in a whole system in the summer season or the like.

In an absorption refrigerating machine 17, high temperature exhaust gas is passed from a high temperature rare gas heater 3 through a high temperature valve 12 to a primary side (high temperature), a water absorber is utilized, cold heat is taken out from a cold water line 18 in a secondary side by a cold water pump 19. In an air cooler device, air taken in from the outside is cooled by cooling water of the absorption refrigerating machine 17, increased in a suction air quantity (weight), supplied to an air compressor 14, prevent the decreasing of a combustion gas quantity of the high temperature rare gas heater 3 in the summer season or the like, so as to prevent the decreasing of output of a gas turbine.