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(11) | EP 2 824 398 A1 |
(12) | EUROPEAN PATENT APPLICATION |
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(54) | Heat pump hot water supply system |
(57) The present invention provides a heat pump hot water supply system which can continue
the operation even when scale builds up while maintaining the hot water outlet temperature
at a target temperature, and can confine the scale buildup to the high temperature-side
water heat exchanger so as to prevent it from spreading to the low temperature-side
water heat exchanger. In a heat pump hot water supply system (1) of a type which controls
the rotation speed of a water pump (13) and thereby the amount of water so that the
hot water outlet temperature becomes equal to a target temperature, a water heat exchanger
(5) is divided into a high temperature-side water heat exchanger (5B) and a low temperature-side
water heat exchanger (5A), and a hot water outlet temperature sensor (21) is provided
on a hot water outlet side of the high temperature-side water heat exchanger (5B),
and a hot water temperature sensor (22) is provided on an outlet side of the low temperature-side
water heat exchanger (5A), and the heat pump hot water supply system includes a control
part (23) which, if a detection value of the outlet hot water temperature sensor (22)
of the low temperature-side water heat exchanger (5A) exceeds a set value when the
performance of the high temperature-side water heat exchanger (5B) is degraded due
to scale buildup, controls so that the hot water outlet temperature is kept equal
to or lower than the set value, and outputs information on the decrease in the hot
water outlet temperature and information on maintenance of the high temperature-side
water heat exchanger (5B).
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{Technical Field}
{Background Art}
{Citation List}
{Patent Literature}
{PTL 1}
Japanese Unexamined Patent Application, Publication No. 2004-144445
{PTL 2}
Japanese Unexamined Patent Application, Publication No. 2011-252676
{Summary of Invention}
{Technical Problem}
{Solution to Problem}
A heat pump hot water supply system according to the present invention is a type of a heat pump hot water supply system which is provided with a water heat exchanger for producing hot water by heating the water with a refrigerant gas discharged from a heat pump or with a heat medium undergoing heat exchange with the refrigerant gas and circulating inside a closed cycle, and which controls a rotation speed of a water pump and thereby an amount of water so that a hot water outlet temperature becomes equal to a target temperature, wherein the water heat exchanger is divided into a high temperature-side water heat exchanger and a low temperature-side water heat exchanger, and a hot water outlet temperature sensor is provided on a hot water outlet side of the high temperature-side water heat exchanger, and a hot water temperature sensor is provided on an outlet side of the low temperature-side water heat exchanger; and the heat pump hot water supply system includes a control part which, if a detection value of the outlet hot water temperature sensor of the low temperature-side water heat exchanger exceeds a set value when performance of the high temperature-side water heat exchanger is degraded due to scale buildup, controls so that the hot water outlet temperature is kept equal to or lower than the set value, and outputs information on decrease in the hot water outlet temperature and information on maintenance of the high temperature-side water heat exchanger.
{Advantageous Effects of Invention}
{Brief Description of Drawings}
{Fig. 1}
Fig. 1 is a configuration diagram of a heat pump hot water supply system according
to a first embodiment of the present invention.
{Fig. 2}
Fig. 2 is a flow diagram of control when scale deposits in the heat pump hot water
supply system.
{Fig. 3}
Figs. 3(A) to 3(C) are maps showing scale occurrence in a water heat exchanger of
the heat pump hot water supply system.
{Fig. 4}
Fig. 4 is a configuration diagram of a heat pump hot water supply system according
to a second embodiment of the present invention.
{Description of Embodiments}
(First Embodiment)
When the supercritical-cycle heat pump 2 using a CO2 refrigerant is operated in the heat pump system 1, a high-temperature, high-pressure refrigerant gas compressed in the compressor 4 is introduced into the water heat exchanger 5 through the refrigerant circuit 10. In the water heat exchanger, the refrigerant flowing through the refrigerant passage 17 of the high temperature-side water heat exchanger 5B and the low temperature-side water heat exchanger 5A and the water circulating to the water passage 18 through the water circuit 12 undergo heat exchange with each other. The water is thereby heated and increased in temperature due to the radiation from the high-temperature, high-pressure refrigerant gas, and delivered as hot water at a temperature set by the setting means such as the remote controller 24.
(Second Embodiment)
{Reference Signs List}
REFERENCES CITED IN THE DESCRIPTION
Patent documents cited in the description