JP2011232000A - Heat pump water heater using co2 refrigerant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump water heater using a CO2 refrigerant, which can achieve an increase in capacity while keeping the size of a container for a component equal to or smaller than a fixed size specified by the High Pressure Gas Safety Act.SOLUTION: The heat pump water heater using the CO2 refrigerant includes refrigerant circulation circuits 3A and 3B using the CO2 refrigerant, which include compressors 4A and 4B, radiators 6A and 6B, decompression means 10A and 10B, and heat absorbers 13A and 13B, respectively, and a heat exchanger 19 for hot-water supply, which includes a water channel 19A for exchanging heat with the radiators 6A and 6B. In the heat pump water heater 1, a plurality of systems of the refrigerant circulation circuits 3A and 3B are provided in parallel for the heat exchanger 19. All inside diameters of the containers for the components of the heat pumps 2A and 2B, which include the plurality of systems of the refrigerant circulation circuits 3A and 3B, respectively, are set at 160 mm or less, and the total freezing capacity thereof is set at 3 refrigeration tons or more.

Description

  The present invention relates to a heat pump hot water supply apparatus using CO2 refrigerant in which a refrigerant circulation circuit is provided in parallel in a plurality of systems with respect to a hot water supply heat exchanger.

  There are two methods for increasing the capacity of a refrigeration apparatus or air conditioner: (1) a method of connecting a plurality of heat source devices in parallel, and (2) a method of installing a plurality of compressors in one heat source device in parallel. Is common. The method (1) requires piping and control for oil equalization, but can easily increase the capacity. However, the cost merit cannot be expected very much. On the other hand, since the refrigerant circuit can be provided in the same unit in the method (2), only one cabinet is required, and cost reduction can be expected. However, since the refrigerant is used by being combined in one circuit, the amount of the refrigerant is doubled, and a container such as a compressor, an oil separator, or a receiver must be enlarged.

  Even in a heat pump hot water supply apparatus using a CO2 refrigerant, it is expected that the capacity will increase in the future. However, at present, the method (1) is mainly used. The reason is that in the case of the R410A refrigerant, the design pressure is 4.15 MPa on the high pressure side and 2.21 MPa on the low pressure side, whereas in the case of the CO2 refrigerant, the design pressure is several times higher, 14 MPa on the high pressure side and 8.5 MPa on the low pressure side. Because. Nevertheless, as a method of (2), as shown in Patent Documents 1 and 2, a supercritical cycle heat pump hot water supply apparatus in which a plurality of compressors are connected in parallel, or a compressor, a radiator, a decompression means, There has been proposed a heat pump hot water supply apparatus using a CO2 refrigerant in which at least one of a heat absorber, a heat exchanger for hot water supply having a water flow path for exchanging heat with a radiator, and a plurality of water flow paths is provided.

Japanese Patent No. 4016875 JP 2003-343914 A

  However, as shown in Patent Document 1, when a configuration in which a plurality of compressors are simply connected in parallel, the design pressure is as high as 8.5 MPa even on the low pressure side, and the compressor, oil separator, receiver, accumulator, etc. The thickness of the container must be increased, and the tendency to increase as the capacity increases. This increases the cost, and increases the manufacturing difficulty. In particular, if the refrigerating capacity is 3 tons or more, it is necessary to comply with the High Pressure Gas Safety Law, and containers with an inner diameter of 160 mm or more fall under the container specified by the High Pressure Gas Safety Law. Costs have increased significantly, and this has become a bottleneck in increasing capacity.

  On the other hand, as shown in Patent Document 2, even when a plurality of compressors are used, if a plurality of independent refrigerant circulation circuits are configured for each compressor without joining the refrigerant (see FIG. 9), Capacities can be increased without enlarging containers such as oil separators, receivers, and accumulators. However, if the refrigeration capacity of individual heat pumps increases and the amount of refrigerant required increases, the size of each container must be increased to an inner diameter of 160 mm or more, and it becomes necessary to comply with the High Pressure Gas Safety Law. One of the issues is how to increase the capacity of the heat pump water heater using CO2 refrigerant.

  The present invention has been made in view of such circumstances, and it is possible to increase the capacity of CO2 while keeping the container of the component equipment to a size equal to or less than a certain size specified by the High Pressure Gas Safety Law. It aims at providing the heat pump hot-water supply apparatus using a refrigerant | coolant.

In order to solve the above problems, the heat pump water heater using the CO2 refrigerant of the present invention employs the following means.
That is, the heat pump water heater using the CO2 refrigerant according to the present invention has a refrigerant circulation circuit using the CO2 refrigerant including a compressor, a radiator, a decompression means, and a heat absorber, and a water flow path for exchanging heat with the radiator. A heat pump for hot water supply, and a heat pump hot water supply apparatus using CO2 refrigerant in which the refrigerant circulation circuit is provided in parallel with a plurality of systems with respect to the heat exchanger for hot water supply. The container sizes of the constituent devices of the respective heat pumps are all set to an inner diameter of 160 mm or less, and the total refrigeration capacity is set to 3 refrigeration tons or more.

  According to the present invention, in a heat pump hot water supply apparatus using CO2 refrigerant in which a refrigerant circulation circuit is provided in parallel with a plurality of systems with respect to a hot water supply heat exchanger, each of the heat pumps configured with a plurality of refrigerant circulation circuits. Since all the container sizes of the component equipment are 160 mm inner diameter or less and the total refrigeration capacity is 3 refrigeration tons or more, when increasing the capacity of the heat pump water heater using CO2 refrigerant, the heat exchanger for hot water supply On the other hand, the total refrigeration capacity is 3 capacities of 3 tons or more by connecting two or more heat pumps connected in parallel to each other in a size of 160 mm or less in the size of the equipment constituting the refrigerant circuit. The heat pump hot water supply apparatus using the CO2 refrigerant of the above can be configured. Accordingly, a heat pump hot water supply apparatus using CO2 refrigerant is maintained while keeping the container of the equipment constituting the heat pump using CO2 refrigerant having a high design pressure of 14 MPa on the high pressure side and 8.5 MPa on the low pressure side to a certain size or less. The capacity can be increased, and various problems associated with the increase in the size of the container can be solved. Moreover, since the container sizes of the devices constituting the individual heat pumps are all containers with an inner diameter of 160 mm or less, they do not fall under the container stipulated in the High Pressure Gas Safety Law, simplify the manufacturing process, omit various tests, etc. Thus, the manufacturing cost can be greatly reduced. In addition, since multiple refrigerant circulation circuits are provided in parallel, the oil leveling mechanism and oil leveling control between the multiple compressors are no longer required, the configuration is simplified, and the reliability of individual heat pumps is improved. Can do.

  Furthermore, the heat pump water heater using the CO2 refrigerant of the present invention is the above-described heat pump water heater using the CO2 refrigerant, wherein the compressors of the plurality of refrigerant circulation circuits are each a two-stage compressor, and the heat dissipation And a gas injection circuit for injecting the gas refrigerant separated by the intermediate pressure receiver provided on the downstream side of the vessel into the refrigerant compressed to the intermediate pressure.

  According to the present invention, the compressors of the refrigerant circulation circuits of a plurality of systems are each a two-stage compressor, and the gas refrigerant separated by the intermediate pressure receiver provided on the downstream side of the radiator is compressed to an intermediate pressure. Because it has a gas injection circuit that injects into the refrigerant, the heat pump's heating capacity and coefficient of performance (COP) are improved by improving the compression efficiency by compressing the CO2 refrigerant in two stages and the economizer effect by the gas injection circuit Therefore, the hot water supply performance can be further improved. In addition, since the gas injection circuit is also provided for each refrigerant circulation circuit, gas injection can be performed almost equally to each compressor, and the imbalance of the gas injection amount between the compressors can be eliminated.

  Furthermore, the heat pump water heater using the CO2 refrigerant of the present invention is constituted by two refrigerant circulation circuits among the plurality of refrigerant circulation circuits in the heat pump water heater using any one of the above-described CO2 refrigerants. The heat pump for hot water supply and the heat exchanger for hot water supply are integrated into a module as a main unit, and the third and subsequent heat pumps are respectively modularized as sub-units and combined with the main unit according to the required refrigeration capacity. It is characterized by being used.

  According to the present invention, the heat pump constituted by two refrigerant circulation circuits of a plurality of refrigerant circulation circuits and the heat exchanger for hot water supply are integrated into a module as a main unit. Since each heat pump is modularized as a subunit and used in combination with the main unit according to the required refrigeration capacity, when changing the hot water supply system to each refrigeration capacity, simply change the number of subunits combined. The refrigeration capacity can be changed to make a series. Therefore, it is possible to easily increase the capacity, and productivity can be improved.

  Furthermore, the heat pump water heater using the CO2 refrigerant according to the present invention is the above-described heat pump water heater using the CO2 refrigerant, wherein the main unit is air heat formed by being bent into a planar shape, an L shape, or a U shape. Two heat absorbers composed of exchangers are arranged in a quadrilateral shape so as to be opposed to each other on a lower unit in which other equipment is accommodated, and the subunit is folded into a U-shape. The heat absorber constituted by the air heat exchanger formed in this manner is arranged on the lower unit in which other devices are accommodated, and the main unit and the subunits are used in parallel as appropriate. It is characterized by that.

  According to the present invention, the main unit is a lower unit in which two heat absorbers configured by an air heat exchanger bent into a planar shape, an L shape, or a U shape are accommodated with other devices. The sub unit is configured to be assembled in a quadrilateral shape so as to be opposed to each other, and the subunit is a heat absorber constituted by an air heat exchanger formed by bending in a U shape, and other devices are accommodated. Since the number of main units and sub-units is appropriately arranged in parallel, the width of the sub-units is configured to be approximately half the width of the main unit. Units can be modularized. Therefore, the size of the hot water supply apparatus for each refrigeration capacity can be defined in advance, and installation space can be secured and installation can be facilitated.

  According to the present invention, when the capacity of a heat pump water heater using CO2 refrigerant is increased, the heat pump having all the container sizes of the equipment constituting the refrigerant circulation circuit as a container having an inner diameter of 160 mm or less is compared with the heat exchanger for hot water supply. By connecting two or more systems in parallel, it is possible to construct a heat pump water heater using a large capacity CO2 refrigerant with a total refrigeration capacity of 3 refrigeration tons or more. The capacity of the heat pump water heater using the CO2 refrigerant can be increased while the container of the equipment constituting the heat pump using the CO2 refrigerant as high as 8.5 MPa on the side is kept to a certain size or less. Various problems associated with the increase in size can be solved. Moreover, since the container sizes of the devices constituting the individual heat pumps are all containers with an inner diameter of 160 mm or less, they do not fall under the container stipulated in the High Pressure Gas Safety Law, simplify the manufacturing process, omit various tests, etc. Thus, the manufacturing cost can be greatly reduced. In addition, since multiple refrigerant circulation circuits are provided in parallel, the oil leveling mechanism and oil leveling control between the multiple compressors are no longer required, the configuration is simplified, and the reliability of individual heat pumps is improved. Can do.

It is a circuit block diagram of the heat pump hot-water supply apparatus using the CO2 refrigerant | coolant which concerns on 1st Embodiment of this invention. It is a disassembled perspective view of the unit structural example of the heat pump hot-water supply apparatus using the CO2 refrigerant | coolant which concerns on 2nd Embodiment of this invention. It is a disassembled perspective view of the modification of the unit structural example shown in FIG. It is a disassembled perspective view of the other modification of the unit structural example shown in FIG.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a circuit configuration diagram of a heat pump water heater using a CO 2 refrigerant according to the first embodiment of the present invention.
A heat pump hot water supply apparatus 1 using CO2 refrigerant according to the present embodiment includes supercritical cycle heat pumps 2A and 2B using CO2 refrigerant constituted by independent refrigerant circulation circuits 3A and 3B.

  Each of the heat pumps 2A and 2B includes, for example, a two-stage compressor 4A and 4B that compresses the refrigerant in two stages, a rotary compression mechanism on the lower stage side and a scroll compression mechanism on the higher stage side, and oil that separates the lubricating oil in the refrigerant gas. Separators 5A and 5B, radiators (gas coolers) 6A and 6B for radiating refrigerant gas, first electronic expansion valves (decompression means) 7A and 7B for controlling the outlet side refrigerant temperature of the radiators 6A and 6B, and refrigerant Intermediate pressure receivers 8A and 8B that perform gas-liquid separation, intercoolers 9A and 9B that exchange heat between the intermediate pressure refrigerant and the refrigerant gas sucked into the compressors 4A and 4B, and a second electronic expansion valve that depressurizes the intermediate pressure refrigerant ( Pressure reducing means) 10A, 10B, supercooling coils 11A, 11B, and heat absorbers (air heat exchangers) 13A, 13B for exchanging heat between the outside air from the fans 12A, 12B and the refrigerant are cooled in this order. Refrigerant circuit 3A closed cycles connected by piping, it is constructed by 3B.

  Each of the heat pumps 2A and 2B includes an oil return circuit 14A and 14B for returning the oil separated by the oil separators 5A and 5B to the two-stage compressors 4A and 4B, and a heat absorber (air heat exchanger) at a low outside temperature. ) Electromagnetic valves 15A and 15B for defrosting frost accumulated on 13A and 13B by introducing hot gas refrigerant discharged from two-stage compressors 4A and 4B into heat absorbers (air heat exchangers) 13A and 13B are provided. The intermediate-pressure refrigerant gas that is separated by the hot gas bypass circuits 16A and 16B and the intermediate-pressure receivers 8A and 8B is sucked into the high-stage scroll compression mechanism of the two-stage compressors 4A and 4B. Gas injection circuits 18A and 18B provided with electromagnetic valves 17A and 17B for injection (injection) are provided.

  The radiators (gas coolers) 6A and 6B of the heat pumps 2A and 2B constitute a hot water supply heat exchanger 19 that heat-exchanges the water flowing through the water flow path 19A and the refrigerant and heats the water to produce hot water. Yes. The hot water supply heat exchanger 19 is connected to a water flow path 19A and a hot water storage tank 20 via a water circulation circuit 23 having a water circulation pump 21 and an electromagnetic valve 22, and is circulated from the hot water storage tank 20 via the water circulation pump 21. The water is heated to a predetermined temperature of warm water and stored in the hot water storage tank 20. The water circulation circuit 23 is connected to a water supply pipe (not shown) such as tap water, and the hot water storage tank 20 is connected to a hot water supply pipe (not shown) for supplying hot water to a required location. It has become.

  Thus, the heat pump hot water supply apparatus 1 of the present embodiment is configured such that the refrigerant circulation circuits 3A and 3B of a plurality of independent heat pumps 2A and 2B are connected in parallel to the hot water supply heat exchanger 19, respectively. The water can be heated by the heat exchanger 19 for hot water supply via the radiators 6A and 6B of the heat pumps 2A and 2B. The individual heat pumps 2A and 2B have all the container sizes such as the two-stage compressors 4A and 4B, the oil separators 5A and 5B, the intermediate pressure receivers 8A and 8B, and the accumulator (not shown) constituting the refrigerant circulation circuits 3A and 3B. The container has an inner diameter of 160 mm or less. When the capacity of the heat pump water heater 1 is increased and the refrigeration capacity is 3 refrigeration tons or more, the container sizes of the devices constituting the refrigerant circulation circuits 3A and 3B are all containers having an inner diameter of 160 mm or less. At least two or more heat pumps 2A, 2B are connected in parallel to form a large-capacity heat pump water heater 1.

With the configuration described above, according to the present embodiment, the following operational effects can be obtained.
In the heat pump water heater 1 using the CO2 refrigerant, the refrigerant compressed in the second stage by the two-stage compressors 4A and 4B is separated from the oil in the refrigerant by the oil separators 5A and 5B, and then the radiator (gas cooler). 6A and 6B, where heat is exchanged with water flowing on the water flow path 19A side of the hot water supply heat exchanger 19. This water is heated and heated by heat radiation from the refrigerant, and then returns to the hot water storage tank 20 until the hot water temperature in the hot water storage tank 20 reaches a predetermined temperature, and the hot water storage tank 20 and the hot water supply heat exchanger 19. The hot water storage operation is terminated when the hot water temperature reaches a predetermined temperature.

  The refrigerant cooled by exchanging heat with water in the hot water supply heat exchanger 19 is depressurized by the first electronic expansion valves (decompression means) 7A and 7B, reaches the intermediate pressure receivers 8A and 8B, and is separated into gas and liquid. The separated gas refrigerant is injected into the refrigerant gas compressed to an intermediate pressure by the low-stage compression mechanism of the two-stage compressors 4A and 4B via the electromagnetic valves 17A and 17B and the gas injection circuits 18A and 18B. The On the other hand, after the liquid refrigerant is cooled, it is depressurized by the second electronic expansion valves (decompression means) 10A and 10B through the intercoolers 9A and 9B, and becomes a low-temperature and low-pressure refrigerant to the heat absorber (air heat exchanger) 13A, 13B. By the economizer effect by this gas injection, the heat capacity and coefficient of performance (COP) of each heat pump 2A, 2B can be improved, and hot water supply performance can be improved.

  The refrigerant that has flowed into the heat absorbers (air heat exchangers) 13A and 13B exchanges heat with the outside air blown through the fans 12A and 12B, and absorbs heat from the outside air to be evaporated into gas. The gasified refrigerant is sucked into the two-stage compressors 4A and 4B through the intercoolers 9A and 9B and is recompressed. Thereafter, the same operation is repeated to provide hot water. During hot water storage operation, when frost accumulates on the heat absorbers 13A and 13B due to low outside air temperature, the solenoid valves 15A and 15B are opened, and the hot and hot hot gas compressed by the two-stage compressors 4A and 4B is used as the hot gas. A defrosting operation is performed by introducing the heat absorbers 13A and 13B via the bypass circuits 16A and 16B.

  Thus, when the capacity of the heat pump water heater 1 using the CO2 refrigerant is increased, all the container sizes of the devices constituting the refrigerant circulation circuits 3A and 3B are set to containers having an inner diameter of 160 mm or less with respect to the hot water supply heat exchanger. By adopting a configuration in which two or more heat pumps 2A and 2B are connected in parallel, a large-capacity heat pump hot water supply apparatus 1 having a total refrigeration capacity of 3 refrigeration tons or more can be configured. As a result, the CO2 refrigerant was used while the containers of the devices constituting the heat pumps 2A and 2B using the CO2 refrigerant having a high design pressure of 14 MPa on the high pressure side and 8.5 MPa on the low pressure side were kept to a certain size or less. The capacity of the heat pump hot water supply device can be increased, and various problems such as an increase in pressure resistance due to an increase in wall thickness due to an increase in the size of each container, an improvement in manufacturing difficulty, and an increase in cost can be solved. .

  Moreover, since the container sizes of the devices constituting the individual heat pumps 2A and 2B are all containers having an inner diameter of 160 mm or less, they do not fall under the container stipulated in the High Pressure Gas Safety Law, simplify the manufacturing process, and perform various tests. Manufacturing costs can be significantly reduced by omission. Further, since the refrigerant circulation circuits 3A and 3B are configured to be connected in parallel to a plurality of systems, an oil leveling mechanism, oil leveling control, etc. between the plurality of two-stage compressors 4A and 4B are unnecessary, and the configuration is simple. And the reliability of the individual heat pumps 2A and 2B can be improved.

  Further, a plurality of refrigerant circulation circuits 3A, 3B inject gas refrigerant separated by the intermediate pressure receivers 8A, 8B into intermediate pressure refrigerant gas by the two-stage compressors 4A, 4B, respectively. Therefore, the heat capacity and coefficient of performance (COP) of the heat pumps 2A and 2B are improved by improving the compression efficiency by compressing the CO2 refrigerant in two stages and the economizer effect by the gas injection circuits 18A and 18B. Can do. Accordingly, the hot water supply performance can be further improved, and the gas injection circuits 18A and 18B are also provided for the refrigerant circulation circuits 3A and 3B. Therefore, the gas injection is performed almost equally to the two-stage compressors 4A and 4B. It is possible to eliminate the imbalance in the amount of gas injection between the compressors.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
This embodiment is different from the above-described first embodiment in that a configuration in the case where the heat pump hot water supply device 1 using the CO 2 refrigerant is specifically unitized is shown. Since other points are the same as those in the first embodiment, description thereof will be omitted.
In the present embodiment, heat pumps 2A and 2B, each of which is constituted by two refrigerant circulation circuits 3A and 3B, each having a container having an inner diameter of 160 mm or less, and a hot water supply heat exchanger 19 are provided. By integrating, as shown in FIGS. 2 to 4, the heat pump 3C (not shown) is modularized as the main unit 30 and the containers of the third and subsequent components are containers having an inner diameter of 160 mm or less. Is modularized as a subunit 31 and is configured to be used in combination with the main unit 30 as appropriate in accordance with the required refrigeration capacity.

  The main unit 30 includes, in the upper unit 30A, two heat absorbers 13A and 13B, each of which includes fans 12A and 12B and an air heat exchanger that is bent into an L shape as shown in FIG. Alternatively, as shown in FIG. 3, two heat absorbers 13A ′ and 13B ′ composed of a planar air heat exchanger, or air bent into a U-shape as shown in FIG. Two heat absorbers 13A ″, 13B ″ composed of heat exchangers are arranged to face each other and assembled into a quadrilateral shape, and other devices are accommodated in the lower unit 30B installed at the lower part thereof. It is set as the structure. Further, the sub unit 31 includes a fan 12C (not shown) and an air heat exchanger 13C formed by bending it into a U-shape and accommodated in the upper unit 31A, and is installed in the lower part. In the lower unit 30B, other devices are accommodated and arranged.

  As described above, among the plurality of refrigerant circulation circuits 3A and 3B connected in parallel, the containers of the respective constituent devices configured by the two refrigerant circulation circuits 3A and 3B have an inner diameter of 160 mm or less. The heat pumps 2A and 2B and the heat exchanger 19 for hot water supply are integrated into a module as a main unit 30, and the heat pump 3C in which the containers of the third and subsequent components are containers having an inner diameter of 160 mm or less (not shown) ) Is modularized as the subunit 31 and is used in combination with the main unit 30 according to the required refrigeration capacity, so that when the heat pump water heater 1 is serialized for each refrigeration capacity, the number of combinations of the subunits 31 is Just by changing the refrigeration capacity can be changed into a series. As a result, the capacity can be easily increased, and the productivity can be improved.

  The main unit 30 includes two heat absorbers 13A, 13B, 13A ′, 13B ′, 13A ″, which are constituted by air heat exchangers that are bent into a planar shape, an L shape, or a U shape. 13B ″ is configured to be arranged in a quadrilateral shape so as to be opposed to each other on the lower unit 30B in which other devices are accommodated, and the sub-unit 31 is an air heat exchange formed by being folded into a U-shape. The heat absorber 13 </ b> C configured by a vessel is configured to be disposed on the lower unit 31 </ b> B in which other devices are accommodated, and the main unit 30 and the subunits 31 are appropriately arranged in parallel and used. Therefore, the width dimension of the sub-unit 31 is approximately half the width dimension of the main unit 30, and each unit 30, 31 is modularized. It can be. Therefore, the size of the heat pump water heater 1 for each refrigeration capacity can be defined in advance, and installation space can be secured and installation can be facilitated.

  In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably. For example, in the above-described embodiment, an example in which the two-stage compressors 4A and 4B are used for the heat pumps 2A and 2B has been described, but the compressor may be a single-stage compressor. Further, the gas injection circuits 18A and 18B are not essential and may be configured without a gas injection circuit. Furthermore, although the example which used the gas-liquid separator (intermediate pressure receiver 8A, 8B) was demonstrated as gas injection circuit 18A, 18B, it may replace with this and may be set as the structure using an intermediate heat exchanger.

1 Heat pump water heater 2A, 2B using CO2 refrigerant Heat pump 3A, 3B Refrigerant circulation circuit 4A, 4B Two-stage compressor 6A, 6B Radiator 7A, 7B First electronic expansion valve (pressure reduction means)
8A, 8B Intermediate pressure receiver 10A, 10B Second electronic expansion valve (pressure reduction means)
13A, 13A ′, 13A ″, 13B, 13B ′, 13B ″, 13C Heat absorbers 18A, 18B Gas injection circuit 19 Heat exchanger for hot water supply 19A Water flow path 30 Main unit 30B Lower unit 31 Sub unit 31B Lower unit

Claims (4)

A refrigerant circulation circuit using CO2 refrigerant including a compressor, a radiator, a decompression means and a heat absorber, and a heat exchanger for hot water supply having a water flow path for exchanging heat with the radiator,
In the heat pump hot water supply apparatus using CO2 refrigerant in which the refrigerant circulation circuit is provided in parallel with a plurality of systems with respect to the hot water supply heat exchanger,
CO2 refrigerant characterized in that the container size of each component of each heat pump constituted by the plurality of refrigerant circulation circuits is set to an inner diameter of 160 mm or less, and its total refrigeration capacity is 3 refrigeration tons or more. Heat pump water heater using   Each of the compressors of the plurality of refrigerant circulation circuits is a two-stage compressor, and the gas refrigerant separated by the intermediate pressure receiver provided on the downstream side of the radiator is compressed into an intermediate pressure. The heat pump hot-water supply apparatus using the CO2 refrigerant according to claim 1, further comprising a gas injection circuit for injecting the gas into the heat pump.   Of the plurality of refrigerant circulation circuits, a heat pump configured by two refrigerant circulation circuits and the hot water heat exchanger are integrated into a module as a main unit. The heat pump hot-water supply apparatus using CO2 refrigerant according to claim 1 or 2, wherein each unit is modularized and used in combination with the main unit according to a required refrigeration capacity. In the main unit, two heat absorbers composed of an air heat exchanger bent into a planar shape, L-shape or U-shape are arranged opposite to each other on a lower unit in which other devices are accommodated. The sub-unit has a heat sink composed of an air heat exchanger formed by bending it into a U-shape on a lower unit in which other devices are accommodated. The heat pump hot water supply apparatus using CO2 refrigerant according to claim 3, wherein the heat pump water heater is configured to be arranged, and the number of the main units and the sub units are appropriately arranged in parallel.

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