To utilize remaining heat in a plurality of ways by providing a heat carrying liquid inlet being coupled with the inlet of a heat receiving pipe and a plurality of heat carrying liquid outlets being coupled with the outlet and the branch outlet of the heat receiving pipe so that heat carrying liquid having temperature difference can be taken out.

City water is supplied, through action of a heat carrying liquid pump 413, to a refrigerant side double tube heat exchanger 600 and subjected to heat exchange. An engine cooling water side double tube heat exchanger 601 supplies high temperature engine cooling water from upstream side of an engine cooling water inlet 601c to an engine cooling water side radiator pipe 403. Low temperature engine cooling water subjected to heat exchange through the engine cooling water side radiator pipe 403 and an engine waste heat receiving pipe 415 is discharged from an engine cooling water outlet 601d. High temperature city water receiving heat from a branch outlet 601e and a heat carrying liquid outlet 601b is supplied from the engine waste heat receiving pipe 415 to a hot water supply tank 2201 and a floor heating panel 556.