JP2008175519A - Heat pump water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump water heater with small heat loss, capable of carrying out efficient boiling operation. <P>SOLUTION: The heat pump water heater is composed by connecting a heat pump unit 1 having a coolant circuit 25 and heating water, and a tank unit 2 provided with a hot water storage tank 8 by a water side piping 11 conveying water in the hot water storage tank 8 to the heat pump unit 1, and a hot water side piping 12 conveying hot water produced by the heat pump unit 1 into the hot water storage tank 8. A hot water side piping connection part 14 between the heat pump unit 1 and the hot water side piping 12 are arranged in a casing 17 of the heat pump unit 1 via a heat insulating material 21b. When storing the hot water boiled by the heat pump unit 1 in the hot water storage tank 8, the heat loss radiated into the air from the hot water side piping 12 via the hot water side piping connection part 14 of the heat pump unit 1 and the casing 17 of the heat pump unit 1 can be reduced, and energy-saving and efficient boiling operation can be carried out. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat pump water heater that stores hot water boiled by a heat pump in a hot water storage tank and can be used for hot water supply.

  Conventionally, there is a heat pump water heater as shown in FIG. 3 that can use hot water boiled by a heat pump for hot water supply (see, for example, Non-Patent Document 1). As shown in FIG. 3, the heat pump water heater is configured by connecting a heat pump unit 101 and a tank unit 102 with a water side pipe 111 and a hot water side pipe 112.

  The heat pump unit 101 forms a heat pump cycle by sequentially connecting a compressor 103, a hot water supply heat exchanger 104, an expansion valve 105, and an evaporator 106 in an annular shape. The tank unit 102 includes a hot water storage tank 108, a pump 109, and a temperature control valve 110. Reference numeral 107 denotes a fan that sends the wind of the evaporator 106.

  The water in the hot water storage tank 108 is conveyed by the pump 109 to the hot water supply heat exchanger 104 via the water side pipe connection part 115 of the tank unit 102, the water side pipe 111, and the water side pipe connection part 113 of the heat pump unit 101, and the heat pump Heat is exchanged with the high-temperature refrigerant of the cycle to become high-temperature hot water, and then the hot water storage tank 108 is passed through the hot water side pipe connection part 114, the hot water side pipe 112 of the heat pump unit 101, and the hot water side pipe connection part 116 of the tank unit 102. Stored as hot water. Hot water and hot water stored in the hot water storage tank 108 are mixed by a temperature control valve 110 and adjusted to a predetermined temperature and used as hot water.

119 is a water supply connection part connected to an external water pipe (not shown), 120 is a hot water supply connection part connected to a hot water supply pipe (not shown) for supplying hot water to a bathroom, kitchen, washroom, etc. is there.
Air conditioning and sanitary engineering, Vol. 78, No. 6, p. 15-P. 18

  However, in the configuration of the conventional heat pump water heater, hot water of the heat pump unit 101 is heated until hot water (65 ° C. to 90 ° C.) heated by the hot water supply heat exchanger 104 is conveyed into the hot water storage tank 108. Heat is transferred from the side pipe connection part 114 to the casing 117 of the heat pump unit 101 by heat conduction, and then is radiated from the casing 117 of the heat pump unit 101 into the air, resulting in heat loss.

  In addition, heat is transferred from the hot water side pipe connection 116 of the tank unit 102 to the casing 118 of the tank unit 102 by heat conduction, and then is radiated from the casing 118 of the tank unit 102 into the air, resulting in heat loss. Usually, a heat insulating material (not shown) is installed on the outer circumference of the hot water side pipe 112 and the water side pipe 111 to prevent heat loss, but the casing 117 of the heat pump unit 101 and the casing 118 of the tank unit 102 are insulated. The material is not installed.

Further, a part of the amount of heat conducted from the hot water side pipe connection part 114 of the heat pump unit 101 to the casing 117 of the heat pump unit 101 is transferred to the water in the water side pipe 111 via the water side pipe connection part 113 of the heat pump unit 101. A part of the heat transferred from the hot water side pipe connection part 116 of the tank unit 102 to the casing 118 of the tank unit 102 is transferred to the water side pipe 1 via the water side pipe connection part 115 of the tank unit 102.
11, the temperature of the inlet water of the hot water supply heat exchanger 104 rises.

  Due to the characteristics of the heat pump, if the inlet water temperature of the hot water supply heat exchanger 104 rises, the operating efficiency (COP) of the heat pump cycle will fall. That is, due to heat conduction through the hot water side pipe 112 through the casing 117 of the heat pump unit 101 and the casing 118 of the tank unit 102, only a part of the amount of heat boiled up by the heat pump unit 101 is released into the air as heat loss. However, there was a problem that the operating efficiency (COP) of the heat pump cycle was also lowered.

  The present invention solves the above-mentioned conventional problems, and reduces heat loss from the hot water side piping through the casings of the heat pump unit and the tank unit, and enables heat pump hot water operation with high efficiency by the heat pump unit. The purpose is to provide a machine.

  In order to solve the above-described conventional problems, a heat pump water heater of the present invention includes a heat pump unit that has a refrigerant circuit and heats water, and a tank unit that includes a hot water storage tank. Water in the hot water storage tank is used as the heat pump. A water-side pipe transported to the unit and a hot-water side pipe transporting hot water produced by the heat pump unit into the hot water storage tank are configured, and a connection portion between the heat pump unit and the hot-water side pipe is provided. When the hot water boiled by the heat pump unit is stored in the hot water storage tank through the heat conduction prevention means, when the hot water boiled in the hot water storage tank, the hot pump side pipe connection part of the heat pump unit and the casing of the heat pump unit Reduces heat loss that dissipates heat into the air through the air, and saves energy High-efficiency water heating operation is possible both.

  The heat pump water heater of the present invention includes a heat pump unit that has a refrigerant circuit and heats water, and a tank unit that includes a hot water storage tank, and a water side pipe that transports water in the hot water storage tank to the heat pump unit. The hot water produced by the heat pump unit is connected to a hot water side pipe that conveys the hot water into the hot water storage tank, and a connection part between the heat pump unit and the hot water side pipe, and the heat pump unit and the water side pipe. Is connected to the casing of the heat pump unit through heat conduction prevention means, and heat is radiated from the hot water side pipe to the air via the hot water side pipe connecting part of the heat pump unit and the casing of the heat pump unit. Not only can heat loss be reduced, but also high-efficiency boiling with a heat pump unit Enables operation, it is possible to achieve energy saving.

  The heat pump water heater of the present invention includes a heat pump unit that has a refrigerant circuit and heats water, and a tank unit that includes a hot water storage tank, and a water-side pipe that transports water in the hot water storage tank to the heat pump unit. The hot water produced by the heat pump unit is connected to a hot water side pipe that conveys the hot water into the hot water storage tank, and the connecting portion between the tank unit and the hot water side pipe is connected via the heat conduction preventing means. It is installed in the casing of the tank unit, and heat loss radiated from the hot water side pipe to the air via the hot water side pipe connection part of the tank unit and the casing of the tank unit can be reduced, and energy saving can be achieved.

The heat pump water heater of the present invention includes a heat pump unit that has a refrigerant circuit and heats water, and a tank unit that includes a hot water storage tank, and a water side pipe that transports water in the hot water storage tank to the heat pump unit. The hot water produced by the heat pump unit is connected to a hot water side pipe that conveys the hot water into the hot water storage tank, and a connection portion between the tank unit and the hot water side pipe, and the tank unit and the water side pipe. Is connected to the tank unit casing through heat conduction prevention means, and heat is radiated from the hot water side pipe to the air through the tank unit hot water side pipe connection part and the tank unit casing. Not only can losses be reduced, but also high-efficiency boiling operation with heat pump units is possible, saving energy. It can be achieved.

  The heat pump water heater of the present invention not only can reduce the heat loss radiating from the hot water side pipe to the air via the hot water side pipe connection part of the heat pump unit and the casing of the heat pump unit, but also raises the heat efficiently by the heat pump unit. Operation is possible and energy saving can be achieved.

  A first invention includes a heat pump unit that has a refrigerant circuit and heats water, a tank unit that includes a hot water storage tank, a water side pipe that conveys water in the hot water storage tank to the heat pump unit, and the heat pump unit The hot water produced in 1 is connected with a hot water side pipe that conveys the hot water into the hot water storage tank, and the connecting portion between the heat pump unit and the hot water side pipe is connected to the casing of the heat pump unit via a heat conduction preventing means. When storing the hot water boiled by the heat pump unit in the hot water storage tank, heat loss radiated from the hot water side piping to the hot pump side hot water side piping connection and the casing of the heat pump unit is reduced. In addition, energy saving and high-efficiency boiling operation are possible.

  According to a second aspect of the present invention, there is provided a heat pump unit having a refrigerant circuit and heating water, a tank unit having a hot water storage tank, a water side pipe for transporting water in the hot water storage tank to the heat pump unit, and the heat pump unit. Connected to the hot water side pipe that conveys the hot water produced in the hot water storage tank, a connection part between the heat pump unit and the hot water side pipe, and a connection part between the heat pump unit and the water side pipe Is installed in the casing of the heat pump unit through the heat conduction prevention means, reducing the heat loss that dissipates heat into the air from the hot water side piping through the hot water side piping connection part of the heat pump unit and the casing of the heat pump unit. In addition to being able to perform high-efficiency boiling operation using a heat pump unit, It is possible to achieve the energy reduction.

  According to a third aspect of the present invention, there is provided a heat pump unit having a refrigerant circuit and heating water, a tank unit having a hot water storage tank, a water side pipe for transporting water in the hot water storage tank to the heat pump unit, and the heat pump unit. The hot water produced in step 1 is connected to a hot water side pipe that conveys the hot water produced in the hot water storage tank, and a connecting portion between the tank unit and the hot water side pipe is connected to the casing of the tank unit via a heat conduction preventing means. The heat loss radiated from the hot water side pipe to the air through the hot water side pipe connection part of the tank unit and the casing of the tank unit can be reduced, and energy saving can be achieved.

  According to a fourth aspect of the present invention, there is provided a heat pump unit having a refrigerant circuit and heating water, a tank unit having a hot water storage tank, a water side pipe for transporting water in the hot water storage tank to the heat pump unit, and the heat pump unit. The hot water produced in step 1 is connected to a hot water side pipe that conveys the hot water produced in the hot water storage tank, and a connection part between the tank unit and the hot water side pipe and a connection part between the tank unit and the water side pipe It is installed in the casing of the tank unit through a heat conduction prevention means, and can reduce heat loss radiated from the hot water side pipe to the air through the hot water side pipe connection part of the tank unit and the casing of the tank unit. In addition, a high-efficiency boiling operation by the heat pump unit is possible, and energy saving can be achieved.

  In particular, the fifth aspect of the invention relates to the heat conduction preventing means of the first or second aspect of the invention, in which a urethane foam-based heat insulating material is provided between the connection portion of the heat pump unit and the hot water side pipe and the casing of the heat pump unit. The heat pump unit not only reduces the heat loss that is dissipated into the air from the hot water side piping through the hot water side piping connection part of the heat pump unit and the casing of the heat pump unit, but also increases the Efficient boiling operation is possible and energy saving can be achieved.

  In the sixth invention, in particular, the heat conduction preventing means of the first or second invention is a non-asbestos fiber heat insulating material between the connection portion between the heat pump unit and the hot water side pipe and the casing of the heat pump unit. It is possible to reduce the heat loss that dissipates heat into the air from the hot water side piping through the hot water side piping connection part of the heat pump unit and the casing of the heat pump unit with a simple and durable configuration. In addition, highly efficient boiling operation by the heat pump unit becomes possible, and energy saving can be achieved.

  According to a seventh aspect of the present invention, in particular, the heat conduction preventing means of the first or second aspect of the present invention is a packing-like rubber molded product between the connection between the heat pump unit and the hot water side pipe and the casing of the heat pump unit. It is constructed by inserting, and not only can reduce heat loss from the hot water side piping to the hot water side piping connection of the heat pump unit and the heat pump unit casing to the air with a simple and excellent workability configuration. In addition, high-efficiency boiling operation by the heat pump unit becomes possible, and energy saving can be achieved.

  In an eighth aspect of the invention, in particular, the heat conduction preventing means according to the third or fourth aspect of the invention is provided with a urethane-based heat insulating material between a connecting portion between a tank unit and a hot water side pipe and a casing of the tank unit. With a simple configuration, not only can heat loss from the hot water side piping to the hot water side piping connection of the tank unit and the casing of the tank unit to be released into the air reduced, Efficient boiling operation is possible and energy saving can be achieved.

  According to a ninth invention, in particular, the heat conduction preventing means of the third or fourth invention is a non-asbestos fiber heat insulating material between a connecting portion between a tank unit and a hot water side pipe and a casing of the tank unit. It is possible to reduce the heat loss that radiates heat from the hot water side piping to the hot water side piping connection of the tank unit and the casing of the tank unit with a simple and durable configuration. In addition, high-efficiency boiling operation by a heat pump unit is possible, and energy saving can be achieved.

  According to a tenth aspect of the invention, in particular, the heat conduction preventing means of the third or fourth aspect of the present invention is a packing-like rubber molded product between a connecting portion between a tank unit and a hot water side pipe and a casing of the tank unit. It is constructed by inserting, and not only can reduce heat loss from the hot water side piping to the hot water side piping connection of the tank unit and the casing of the tank unit to the air with a simple and excellent workability. In addition, high-efficiency boiling operation by the heat pump unit becomes possible, and energy saving can be achieved.

  In the eleventh aspect of the invention, in particular, the refrigerant circuit according to any one of the first to tenth aspects of the invention is a supercritical heat pump cycle in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure. Since the refrigerant in the hot water supply heat exchanger is pressurized to a critical pressure or higher by heating the water in the hot water supply heat exchanger with the refrigerant, the water is deprived of the temperature by the water in the hot water supply heat exchanger. Even if it falls, it does not condense. Therefore, it becomes easy to form a temperature difference between the refrigerant and water in the entire area of the hot water heat exchanger, and the heat exchange efficiency can be increased.

In particular, the twelfth invention uses carbon dioxide as the refrigerant in the refrigerant circuit of any one of the first to tenth inventions, and uses relatively inexpensive and stable carbon dioxide as the refrigerant. Product costs can be reduced and reliability can be improved. In addition, since carbon dioxide has an ozone depletion coefficient of zero and a global warming coefficient of about 1/700 that of the alternative refrigerant HFC-407C, it can provide a heat pump water heater that is friendly to the global environment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a configuration diagram of a heat pump water heater in the first embodiment of the present invention, and FIG. 2 is a cross-sectional view of a pipe connection portion on the heat pump unit side of the heat pump water heater.

  1, the heat pump water heater in the present embodiment conveys water in the hot water storage tank 8 to the heat pump unit 1 between the heat pump unit 1 that heats water and the tank unit 2 that includes the hot water storage tank 8. The water side pipe 11 is connected to a hot water side pipe 12 that conveys hot water produced by the heat pump unit 1 into the hot water storage tank 8.

  The heat pump unit 1 is provided with a refrigerant circuit 25 in which a compressor 3, a hot water supply heat exchanger 4, an expansion valve 5, and an evaporator 6 are connected in an annular shape. In the present embodiment, carbon dioxide is used as the refrigerant charged in the refrigerant circuit 25.

  The tank unit 2 includes a hot water storage tank 8 for storing hot water, a circulation pump 9 for transporting the water in the hot water storage tank 8 to the heat pump unit 1, and mixing for producing hot water of a predetermined temperature by mixing the hot water and water in the hot water storage tank 8. A valve 10 is provided.

  As shown in FIG. 2, the casing 17 of the heat pump unit 1 is connected to the water side pipe connection portion 13 of the heat pump unit 1 and the hot water side pipe of the heat pump unit 1 through heat insulating materials 21 a and 21 b which are heat conduction preventing means. The part 14 is installed. Further, the casing 18 of the tank unit 2 is provided with a water side pipe connection part 15 of the tank unit 2 and a hot water side pipe connection part 16 of the tank unit via heat insulating materials 21c and 21d which are also heat conduction preventing means. ing.

  The heat insulating materials 21a to 21d are formed of a material excellent in heat insulating performance such as, for example, a urethane foam material.

  One end of the water side pipe 11 is connected to the water side pipe connection part 13 of the heat pump unit 1, the other end is connected to the water side pipe connection part 15 of the tank unit 2, and one end of the hot water side pipe 12 is connected to the heat pump unit 1. The other end of the hot water side pipe connection part 14 is connected to the hot water side pipe connection part 16 of the tank unit 2.

  Reference numeral 19 denotes a water supply port connected to an external water pipe (not shown), and 20 denotes a hot water supply port connected to a hot water supply pipe (not shown) for supplying hot water to a bathroom, kitchen, washroom, and the like.

  About the heat pump water heater in this Embodiment comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 3 exchanges heat with the water conveyed from the hot water storage tank 8 in the hot water supply heat exchanger 4 to be in a liquid or liquid gas two-phase state, and is decompressed by the expansion valve 5 to become a low temperature. It becomes a low-pressure liquid-gas two-phase refrigerant. Thereafter, in the evaporator 6, heat exchange with the air supplied to the evaporator 6 by the blower 7 is performed, and the operation of the heat pump cycle in which the refrigerant absorbs heat from the air and returns to the compressor 3 is repeated.

  The water at the bottom of the hot water storage tank 8 is conveyed by the circulation pump 9 to the hot water supply heat exchanger 4 through the water side pipe 11, where it exchanges heat with the refrigerant of the heat pump cycle and becomes hot water itself. Is returned to the upper part of the hot water storage tank 8.

  Between the hot water side pipe connection 14 of the heat pump unit 1 and the casing 17 of the heat pump unit, a urethane-based heat insulating material 21b is provided, so that the high temperature (65 to 90) heated by the hot water supply heat exchanger 4 is provided. When the hot water of [° C.] passes through the hot water side pipe connection portion 14 of the heat pump unit 1, heat loss radiated into the air through heat conduction to the casing 17 of the heat pump unit 1 can be reduced.

  Moreover, since the heat insulating material 21d is provided between the hot water side pipe connection part 16 of the tank unit 2 and the casing 18 of the tank unit 2, the high temperature (65-90 degreeC) heated with the hot water supply heat exchanger 4 is provided. When the hot water passes through the hot water side pipe connection portion 16 of the tank unit 2, the heat loss radiated into the air through heat conduction to the casing 18 of the tank unit 2 can be reduced.

  Furthermore, the heat of the hot water (65 to 90 ° C.) flowing through the hot water side pipe 12 is transferred to the water flowing through the water side pipe 11 via the casing 17 of the heat pump unit 1 and the casing 18 of the tank unit. Can be prevented from rising.

  That is, since the rise of the inlet water temperature of the hot water supply heat exchanger 4 can be prevented, a high-efficiency boiling operation by the heat pump unit 1 becomes possible.

  In addition, when performing an operation of boiling all the water in the hot water storage tank 8 into hot water (boiling of the whole amount), the inlet water temperature (water temperature in the water-side pipe 11) of the hot water supply heat exchanger 4 before the operation is finished is 50 to 50. It becomes a relatively high temperature of 60 ° C. Therefore, a heat insulating material 21 a is provided between the water side pipe connection portion 13 of the heat pump unit 1 and the casing 17 of the heat pump unit 1, and heat insulation is provided between the water side pipe connection portion 15 of the tank unit 2 and the casing 18 of the tank unit 2. By providing the material 21c, the heat of the water in the water-side pipe 11 having a relatively high temperature is radiated into the air through heat conduction to the casing 17 of the heat pump unit 1 and the casing 18 of the tank unit 2. Loss can be reduced.

  As described above, according to the heat pump water heater in the present embodiment, the heat of the hot water in the hot water side pipe 12 is transferred into the air through heat conduction to the casing 17 of the heat pump unit 1 and the casing 18 of the tank unit 2. It is possible to reduce the heat loss that is dissipated, and to prevent the heat of the hot water in the hot water side pipe 12 from being transferred to the water in the water side pipe 11 to increase the temperature and lower the heating operation efficiency of the heat pump unit 1. It is.

  In the first embodiment, the urethane foam heat insulating material is used as the heat conduction preventing means. Of course, in addition to the ceramic heat insulating material and the vacuum heat insulating material, non-asbestos fiber heat insulating material is also used. Rubber or the like may be used. Since the urethane-based heat insulating material is relatively inexpensive and has good workability, the material cost and assembly cost of the heat pump water heater can be suppressed. In addition, since the urethane foam heat insulating material has a vibration absorbing effect, the vibration of the casing 17 of the heat pump unit 1 and the casing 18 of the tank unit 2 can be prevented to suppress the generation of noise. Ceramic heat insulating materials are excellent in strength and durability, and vacuum heat insulating materials are excellent in heat insulating performance although they are expensive. Non-asbestos fiber heat insulating materials have both durability and heat insulating properties, and rubber has excellent workability in addition to heat insulating performance and is inexpensive. Thus, various effects can be expected depending on the type of heat insulating material.

  Moreover, when fixing the hot water side pipe connection part 14 of the heat pump unit 1 to the casing 17 of the heat pump unit 1, it is common to use a metal screw or a bolt (not shown). If ceramic screws or bolts are used instead of bolts, it is possible to further reduce heat conduction loss via the screws or bolts. Of course, it may be fixed by an adhesive instead of a screw or a bolt, and if it is fixed by an adhesive, the heat conduction of the screw or the bolt part is lost, so that further reduction of heat loss can be achieved.

  In the present embodiment, the cycle of the refrigerant circuit is a supercritical heat pump cycle in which the high-pressure side refrigerant pressure is equal to or higher than the critical pressure. However, the high-pressure side refrigerant pressure may of course be a critical pressure or lower. In this case, chlorofluorocarbon, ammonia, or the like may be used as the refrigerant.

  As described above, the heat pump water heater according to the present invention can perform a highly efficient boiling operation, and is effective for a heat pump water heater in which the heat pump unit and the tank unit are separated.

Configuration diagram of heat pump water heater in Embodiment 1 of the present invention Sectional view of the pipe connection on the heat pump unit side of the heat pump water heater Configuration diagram of conventional heat pump water heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat pump unit 2 Tank unit 3 Compressor 4 Hot water supply heat exchanger 5 Expansion valve 6 Evaporator 7 Blower 8 Hot water storage tank 9 Circulation pump 10 Mixing valve 11 Water side piping 12 Hot water side piping 13, 15 Water side piping connection part (connection part) )
14, 16 Hot water side piping connection (connection)
17, 18 Casing 19 Water supply port 20 Hot water supply port 21a-21d Thermal insulation (heat conduction prevention means)
25 Refrigerant circuit

Claims (12)

A heat pump unit having a refrigerant circuit and heating water, and a tank unit having a hot water storage tank, a water side pipe for transporting water in the hot water storage tank to the heat pump unit, and hot water produced by the heat pump unit It is configured to be connected with a hot water side pipe that is transported into the hot water storage tank, and a connection portion between the heat pump unit and the hot water side pipe is installed in a casing of the heat pump unit through a heat conduction preventing means. Heat pump water heater. A heat pump unit having a refrigerant circuit and heating water, and a tank unit having a hot water storage tank, a water side pipe for transporting water in the hot water storage tank to the heat pump unit, and hot water produced by the heat pump unit It is configured to be connected by a hot water side pipe transported into the hot water storage tank, and a connection part between the heat pump unit and the hot water side pipe, and a connection part between the heat pump unit and the water side pipe, a heat conduction preventing means The heat pump water heater is installed in a casing of the heat pump unit via A heat pump unit having a refrigerant circuit and heating water, and a tank unit having a hot water storage tank, a water side pipe for transporting water in the hot water storage tank to the heat pump unit, and hot water produced by the heat pump unit The hot water side pipe transported into the hot water storage tank is connected, and the connecting portion between the tank unit and the hot water side pipe is installed in the casing of the tank unit via a heat conduction preventing means. Heat pump water heater. A heat pump unit having a refrigerant circuit and heating water, and a tank unit having a hot water storage tank, a water side pipe for transporting water in the hot water storage tank to the heat pump unit, and hot water produced by the heat pump unit A hot water side pipe transported into the hot water storage tank is connected, and a connection part between the tank unit and the hot water side pipe and a connection part between the tank unit and the water side pipe are provided with heat conduction preventing means. The heat pump water heater is installed in the casing of the tank unit. The heat pump water heater according to claim 1 or 2, wherein the heat conduction preventing means is configured by inserting a urethane-based heat insulating material between a connection portion between the heat pump unit and the hot water side pipe and a casing of the heat pump unit. . The heat pump hot water supply according to claim 1 or 2, wherein the heat conduction preventing means is configured by inserting a non-asbestos fiber heat insulating material between a connection portion between the heat pump unit and the hot water side pipe and a casing of the heat pump unit. Machine. The heat pump water heater according to claim 1 or 2, wherein the heat conduction preventing means is configured by inserting a packing-like rubber molded product between a connection portion between the heat pump unit and the hot water side pipe and a casing of the heat pump unit. . The heat pump water heater according to claim 3 or 4, wherein the heat conduction preventing means is configured by inserting a urethane-based heat insulating material between a connecting portion between the tank unit and the hot water side pipe and a casing of the tank unit. . The heat pump hot water supply according to claim 3 or 4, wherein the heat conduction preventing means is configured by inserting a non-asbestos fiber heat insulating material between a connecting portion between a tank unit and a hot water side pipe and a casing of the tank unit. Machine. The heat pump water heater according to claim 3 or 4, wherein the heat conduction preventing means is configured by inserting a packing-like rubber molded product between a connecting portion between a tank unit and a hot water side pipe and a casing of the tank unit. . The heat pump water heater according to any one of claims 1 to 10, wherein the refrigerant circuit is a supercritical heat pump cycle in which a refrigerant pressure on a high pressure side is equal to or higher than a critical pressure. The heat pump water heater according to any one of claims 1 to 10, wherein carbon dioxide is used as a refrigerant in the refrigerant circuit.

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