| 摘要 |
PURPOSE:To obtain a water having high coefficient of efficiency, by a method wherein a plurality of low heat sources is equipped on a heat exchanger of a heat pump, temperatures of hot water and the plurality of heat sources are detected separately and the low heat source whose temperature difference is minimum is selected and used by changing over the same. CONSTITUTION:The open air 9 is introduced by driving a fan 12 in an air side heat exchanger 3 and either of the open air and well water or discharged hot water is used as a low heat source by selecting and driving either of pumps 13, 14 in a water side heat exchanger 4. Temperatures detected by temperature detectors 16, 17, 18, 19 detecting temperatures of the inside of a hot water tank 8 and the open air 9 as the low heat source and each water temperature of well water tank 10 and a discharged hot water tank 11 are made to apply to an arithmetic unit 20 by converting them into voltage, temperature differences of them with a hot water temperature of the hot water tank 8 are computed and the low heat source whose temperature difference is lowest is selected out of the low heat sources. As a temperature of the low heat source side is dropped, the title device is so constituted that predetermined coefficient of efficiency is obtained by making control operation of a revolution of a compressor 1 through a revolution controller 21 when the temperature difference becomes more than a predetermined value. |
