| 摘要 |
PROBLEM TO BE SOLVED: To suppress temperature drop in a secondary side outlet of a heat exchanger to a minimum even in the case where a winter defrosting operation is necessary, in a hot water supply system in which a heat pump water heater and the heat exchanger are disposed.SOLUTION: A hot water supply system 1 includes: a heat pump water heater 11; a heat exchanger 12; a hot water storage tank 15 for storing hot water supplied from an outlet of a secondary side flow passage 14 of the heat exchanger; temperature sensors 37, 38 for detecting water temperature T3 of a primary side inlet of the heat exchanger 12 and water temperature T4 of a secondary side outlet of the heat exchanger 12 respectively; a circulation pump 17 for supplying cold water to the secondary side flow passage 14 from a lower part water outlet 24 of the hot water storage tank 15; and a control unit 20. In a predetermined period after the completion of a defrosting operation of the heat pump water heater 11, the control unit 20 controls a circulation flow rate supplied to the secondary side flow passage 14 so that the temperature T4 of the secondary side flow passage 14 outlet maintains constant preset temperature without following the temperature T3 of the primary side flow passage 13 inlet.SELECTED DRAWING: Figure 1 |
