COGENERATION SYSTEM

PROBLEM TO BE SOLVED: To provide a technique increasing a storage amount of power generation heat without increasing installation space or an overall weight or causing cost increase by using a member originally provided in a cogeneration system. SOLUTION: An output of a second three way valve 14 is changed from an output 14b to an output 14c during power generation operation, a heating pump 3 is activated, a change-over from a fist water circulation passage 4 to a second water circulation passage 12 is carried out by opening both of a high temperature thermal valve 85 and a low temperature thermal valve 87, and hot water heated by the power generation heat is guided to the second water circulation passage 12. Heat of the hot water is inputted into a heat exchanger 18, and hot water circulating in the heating circulation passages 84, 86 is heated by the heat and stored. Since the power generation heat following power generation can be stored not only in a hot water storage tank 44, but also in hot water using circulation passages such as the heating circulation passages 84, 86, the heat storage amount can be increased without causing enlargement or weight increase of the system. COPYRIGHT: (C)2009,JPO&INPIT