| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the lowering of COP caused by the generation of the water of intermediate temperature, in a hot water storage type water heater wherein the hot water in a bathtub is reheated by using the hot water stored in the hot water storage tank. <P>SOLUTION: This hot water storage type water heater comprising a hot water storage tank unit, a capacity-variable compressor, a refrigerant-water heat exchanger, an expansion valve, an air heat exchanger and the like, further comprises a heating means for heating the hot water in the hot water storage tank, and a capacity-variable circulation pump forming a circulation circuit by connecting the hot water storage tank and the refrigerant-water heat exchanger by a water inlet pipe and a hot water outlet pipe, and the hot water in the hot water storage tank is circulated to the refrigerant-water heat exchanger of the heating means through the circulation circuit by driving the circulation pump, to be heated, and then returned to the hot water storage tank to heat the hot water in the hot water storage tank. A water temperature sensor is mounted on an inlet of the refrigerant-water heat exchanger or the water inlet pipe, a hot water tapping temperature sensor is mounted on an outlet of the refrigerant-water heat exchanger or the hot water outlet pipe, a flow rate c of the circulation pump is controlled on the basis of temperature difference t between a value b of the water temperature sensor and a value a of a hot water temperature sensor, and the rotational frequency of the compressor and an opening of the expansion valve are controlled on the basis of the flow rate c of the circulation pump. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
