JP2007303754A - Heat pump type water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump type water heater capable of minimizing the enlargement of a device size and an increase of cost to obtain an instantaneous high heating capacity in an instantaneous hot water supply operation. <P>SOLUTION: This heat pump type water heater comprises a CO<SB>2</SB>cycle 1 for circulating a CO<SB>2</SB>refrigerant, and a R410A cycle 2 for circulating a R410A refrigerant having compressibility lower than the CO<SB>2</SB>refrigerant. The CO<SB>2</SB>cycle 1 is operated in executing a hot water storing operation for storing hot water heated by a water heat exchanger 32 exchanging heat between the CO<SB>2</SB>refrigerant or R410A refrigerant and the water, in a hot water storage tank 31, and the R410A cycle 2 is operated in executing the instantaneous hot water supply operation for supplying the hot water heated by the water heat exchanger 32 from a prescribed hot water supply port. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat pump type hot water heater that supplies water by heating water by heat exchange with a refrigerant circulating in a heat pump cycle provided with a compressor, an expander, and the like. The present invention relates to a heat pump type hot water heater having two heat pump cycles using refrigerants having different characteristics.

2. Description of the Related Art Conventionally, a heat pump type hot water heater that supplies water by heating water by heat exchange with a refrigerant circulating in a heat pump cycle provided with a compressor, an expander, and the like is well known. In the heat pump type hot water heater, an instantaneous hot water supply operation in which hot water heated by heat exchange with the refrigerant is directly supplied from a hot water outlet, or hot water heated by a heat exchange difference with the refrigerant is stored in a hot water storage tank. Hot water storage operation is executed. In the instantaneous hot water supply operation, it is necessary to instantaneously heat and supply hot water, so instantaneously high heating capacity is required. However, in the hot water storage operation, warm water should be gradually stored in the hot water storage tank. The instantaneous heating capacity may be relatively low.
Here, the refrigerant used in the heat pump type water heater is, for example, a carbon dioxide refrigerant or an HFC refrigerant. The carbon dioxide gas refrigerant can heat water to a high temperature (for example, about 90 ° C.) as a characteristic of the refrigerant. On the other hand, the HFC refrigerant can only heat water to a relatively low temperature (for example, about 65 ° C.) due to the characteristics of the refrigerant. However, when used in, for example, air conditioning equipment and hot water heating equipment, the energy consumption efficiency (COP) is superior to using the HFC refrigerant rather than using the carbon dioxide refrigerant.

On the other hand, Patent Document 1 discloses a heat pump cycle (hereinafter referred to as “CO ₂ cycle”) using a CO ₂ refrigerant (an example of a carbon dioxide gas refrigerant) and a heat pump cycle (an example of an HFC refrigerant) using an R410A refrigerant (an example of an HFC refrigerant). Hereinafter, a heat pump type hot water supply system having both “R410A cycle”) is shown. In this heat pump hot water supply system, either the CO ₂ cycle or the R410A cycle is operated according to the temperature of hot water to be supplied.
Japanese Patent Laying-Open No. 2005-83585

By the way, if the instantaneous hot water supply operation is performed using the CO ₂ cycle, in order to obtain high hot water supply performance (hot water supply temperature, hot water supply amount, etc.) in the instantaneous hot water supply operation, the compressor of the CO ₂ cycle is increased. It is necessary to configure it so that it can output and to obtain a high instantaneous heating capacity.
However, since the CO ₂ refrigerant is compressed and used at a pressure higher than that of the R410A refrigerant, a compressor, an outdoor heat exchanger, and a water heat exchanger used in the CO ₂ cycle in which the CO ₂ refrigerant is circulated are used. The cycle-related parts such as the first are required to have higher pressure resistance than the cycle-related parts including the compressor, the outdoor heat exchanger, and the water heat exchanger used in the R410A cycle. Therefore, when the CO ₂ cycle compressor is configured to be capable of high output, the compressor, the outdoor heat exchanger, and the water heat exchanger are configured as compared with the case where the R410A cycle compressor is configured to be capable of high output. This increases the size and material thickness of the cycle-related parts such as and increases the cost.
Accordingly, the present invention has been made in view of the above circumstances, and the object of the present invention is to suppress as much as possible the increase in the size of the apparatus and the increase in cost for obtaining instantaneous high heating capacity in the instantaneous hot water supply operation. It is in providing the heat pump type hot water heater which can be used.

To achieve the above object, the present invention provides a first heat pump cycle in which a first refrigerant is circulated through at least a first compressor and a first expander, and a pressure lower than that of the first refrigerant. Heat is generated between the second heat pump cycle in which the second refrigerant is circulated through at least the second compressor and the second expander, and the first refrigerant and / or the second refrigerant and water. A water heat exchanger for exchanging and a hot water storage tank for storing hot water heated by the water heat exchanger, wherein the first heat pump cycle supplies hot water heated by the water heat exchanger. The hot water storage tank is operated when a hot water storage operation is performed, and the second heat pump cycle is operated when an instantaneous hot water supply operation for supplying hot water heated by the water heat exchanger from a predetermined hot water supply port is performed. He is characterized by Configured as a pump-type water heater. Here, for example, the first refrigerant is a carbon dioxide refrigerant, and the second refrigerant is an HFC refrigerant.
According to such a configuration, by configuring the second compressor of the second heat pump cycle in which the second refrigerant whose pressure is lower than that of the first refrigerant is circulated, the high output can be configured, In the instantaneous hot water supply operation, an instantaneous high heating capacity can be obtained. Therefore, compared with the case where the first compressor, which requires higher pressure resistance than the second compressor, is configured to be capable of high output, it is possible to suppress an increase in device size and cost.

In the configuration further comprising a common outdoor air heat exchanger that performs heat exchange between the first refrigerant and the second refrigerant and outdoor air, the outdoor air heat exchanger includes the second air heat exchanger. It is desirable that the heat exchange area where heat is exchanged between the refrigerant and the outdoor air is larger than the heat exchange area where heat is exchanged between the first refrigerant and the outdoor air. Specifically, the pipe through which the second refrigerant flows in the outdoor air heat exchanger may be longer than the pipe through which the first refrigerant flows in the outdoor air heat exchanger.
Thereby, when the second compressor is configured to be capable of high output, the instantaneous heating capacity by the second heat pump cycle can be more effectively increased.
In the configuration in which the water heat exchanger is a common water heat exchanger that performs heat exchange between the first refrigerant and the second refrigerant and water, the water heat exchanger includes the second water heat exchanger. It is desirable that the heat exchange area where heat is exchanged between the refrigerant and water is larger than the heat exchange area where heat is exchanged between the first refrigerant and water. Specifically, it is conceivable that the pipe through which the second refrigerant flows in the water heat exchanger is longer than the pipe through which the first refrigerant flows in the water heat exchanger.
Thereby, when the second compressor is configured to be capable of high output, the instantaneous heating capacity by the second heat pump cycle can be more effectively increased.

  By the way, when the heating load of the second heat pump cycle at the time of execution of the instantaneous hot water supply operation is not less than a predetermined magnitude, it is desirable to operate the first heat pump cycle together on that condition. . Thereby, when the heating load of the second heat pump cycle exceeds the heating capacity of the second heat pump cycle, the insufficient heating load can be distributed to the first heat pump cycle. For example, the second heat pump cycle is configured to be shared by any one or more of an air conditioner, a bath circuit, and a floor heating device, and these operations and the instantaneous hot water supply operation are performed simultaneously, This is suitable when a heating load of a predetermined size or more acts on the second heat pump cycle.

  According to the present invention, the second compressor of the second heat pump cycle in which the second refrigerant whose pressure is lower than that of the first refrigerant is circulated is configured to enable high output, thereby Instantaneous high heating capacity can be obtained in hot water supply operation. Therefore, compared with the case where the first compressor, which is required to have higher pressure resistance than the second compressor, is configured to be capable of high output, it is possible to suppress an increase in device size and cost.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
FIG. 1 is a schematic configuration diagram of a heat pump type hot water heater X according to the embodiment of the present invention.
As shown in FIG. 1, the heat pump type hot water heater X includes a heat pump cycle 1 in which a CO ₂ refrigerant (an example of a first refrigerant), which is an example of a carbon dioxide refrigerant, is circulated (an example of a first heat pump cycle, hereinafter). and referred to as "CO ₂ cycle 1"), an example of the carbon dioxide gas an example of R410A refrigerant (second refrigerant which is an example of a low HFC refrigerant pressure than refrigerant) is the heat pump cycle 2 (the second heat pump cycle to be circulated , Hereinafter referred to as “R410A cycle 2”), flowing water paths 30a to 30i, circulation pump 34, water heat exchanger 32 common to the CO ₂ cycle 1 and R410A cycle 2, and the preceding water heat exchanger 32 a hot water storage tank 31 for storing heated hot water, a common outdoor air heat exchanger 13 to the CO ₂ cycle 1 and the R410A cycle 2, the flow A switching valve 41 to 45 are schematic configuration includes a bath circuit 7, a. The heat pump water heater X includes a CPU, a RAM, a ROM, and the like, and includes a control unit (not shown) that controls the heat pump water heater X in an integrated manner.

Here, the CO ₂ refrigerant has different characteristics from the R410A refrigerant and can heat water to a high temperature (about 90 ° C.) as a characteristic of the refrigerant, but has a relatively low energy consumption efficiency (COP). The R410A refrigerant has characteristics different from those of the CO ₂ refrigerant, and can heat water only to a low temperature (about 65 ° C.) as compared with the CO ₂ refrigerant. However, the energy consumption efficiency (COP) is high. , Suitable for relatively low boiling temperature. As will be described later, in the heat pump type water heater X, the CO ₂ cycle 1 in which the CO ₂ refrigerant is circulated is mainly used for hot water storage operation, and the R410A cycle 2 in which the R410A refrigerant is circulated is mainly an instantaneous hot water supply operation. Used in
Other examples of the R410A refrigerant include R407C / E, R404A, R507A, and R134a. Further, the two different refrigerants used in the heat pump type hot water heater X are not limited to the carbon dioxide refrigerant and the HFC refrigerant, and may use refrigerants having different characteristics such as heat exchange efficiency and energy consumption efficiency.

The flowing water path 30a is a water distribution path that continues from the water supply port through the hot water storage tank 31, the circulation pump 34, and the flowing water switching valve 41 to the flowing water path 30c, and the flowing water path 30b is a water supply port or flowing water path 30f. To the water flow path 30c through the water flow switching valve 41 and the water flow path 30c. In the lower layer of the hot water storage tank 31, water supplied from the water supply port is stored, and in the upper layer, hot hot water heated by the water heat exchanger 32 is stored.
In addition, the flowing water path 30 c is a water circulation path that continues from the flowing water switching valve 41 to the water heat exchanger 32. And the water which flowed out from the said water heat exchanger 32 flows in into the flowing water path 30d following a hot-water supply port.
The flowing water path 30d is constituted by a flowing water switching valve 42, 44, 45 provided on the flowing water path 30d, a flowing water path 30e following the hot water storage tank 31, and a bath recuperation heat exchanger 72 described later of the bath circuit 7. Is connected to a flowing water path 30f that is connected to a bathtub 74 (to be described later) of the bath circuit 7. Therefore, the flowing water switching valves 42, 44, and 45 are controlled by the control unit, so that water on the flowing water path 30 d flows into the hot water storage tank 31, the bath recuperation heat exchanger 72, and the bathtub 74. Supplied.
The flowing water path 30h is a water distribution path from the hot water storage tank 31 through the flowing water switching valve 43 to the hot water supply port, and the distribution path 30i is water from the water supply port through the flowing water switching valve 43 to the hot water supply port. Is a distribution channel.

The water heat exchanger 32 is common to the CO ₂ cycle 1 and the R410A cycle 2, and includes a CO ₂ refrigerant circulated in the CO ₂ cycle 1 and an R410A refrigerant circulated in the R410A cycle 2. The heat exchange is performed with water flowing on the flowing water path 30c.
For example, the water heat exchanger 32 includes the pipe 14 provided in the water heat exchanger 32 through which the CO ₂ refrigerant flows, the pipe 33 provided on the flowing water path 30c through which water flows, and the R410A refrigerant. The pipe 25 through which the gas flows and the pipe 33 are configured to come into contact with each other. Thus, in the water heat exchanger 32, the CO ₂ refrigerant and the water flowing on the flowing water path 30c are operated when the CO ₂ cycle 1 is operated, and the R410A refrigerant and the flowing water path are operated when the R410A cycle 2 is operated. When the CO ₂ cycle 1 and the R410A cycle 2 are in operation, heat exchange is performed between the CO ₂ refrigerant and the R410A refrigerant and water flowing on the flowing water path 30c. Water on the flowing water path 30c is heated. Therefore, in the heat pump type hot water supply apparatus X, the CO ₂ cycle 1 and the R410A cycle 2 can be operated at the same time, so that the heating ability exceeding the individual heating ability can be exhibited.
Here, the water heat exchanger 32 has a heat exchange area where heat is exchanged between the R410A refrigerant and water than a heat exchange area where heat is exchanged between the CO ₂ refrigerant and water. Designed to be large. That is, the heat exchange capacity with water in the water heat exchanger 32 is higher in the R410A refrigerant than in the CO ₂ refrigerant. For example, it is conceivable that the refrigerant pipe through which the R410A refrigerant flows in the water heat exchanger 32 is designed to be longer than the refrigerant pipe through which the CO ₂ refrigerant refrigerant flows. Thus, increasing the heat exchange capacity of the low-pressure cycle (R410A cycle 2) can lower the design pressure of each component than increasing the heat exchange capacity of the high-pressure cycle (CO ₂ cycle 1). The increase can be suppressed.

The outdoor air heat exchanger 13 is common to the CO ₂ cycle 1 and the R410A cycle 2, and is circulated to the CO ₂ refrigerant circulated in the CO ₂ cycle 1 and the R410A cycle 2. by performing the heat exchange between the R410A refrigerant and the outside air is intended to heat or cool the CO ₂ refrigerant and the R410A refrigerant.
Here, the outdoor air heat exchanger 13 has a heat exchange area where heat exchange is performed between the R410A refrigerant and outdoor air, and heat exchange where heat exchange is performed between the CO ₂ refrigerant and outdoor air. It is designed to be larger than the area. That is, the heat exchange capacity with the outdoor air in the outdoor air heat exchanger 13 is higher in the R410A refrigerant than in the CO ₂ refrigerant. For example, it is conceivable that the refrigerant pipe through which the R410A refrigerant flows in the outdoor air heat exchanger 13 is designed to be longer than the refrigerant pipe through which the CO ₂ refrigerant refrigerant flows.

The bath circuit 7 includes a bath remedy heat exchanger 72 and a circulation pump 71 provided on the flowing water path 30f, a bathtub 74 provided on the flowing water path 30g, the bathtub 74, and the bath remedy. And a bath water retreat path 75 for connecting the heat exchanger 72 and the circulation pump 73 in order.
In the bath circuit 7, the flowing water switching valve 45 is controlled by the control unit, so that hot water heated by the water heat exchanger 32 and flowing on the flowing water path 30 d is supplied to the bathtub 74.
Further, in the bath circuit 7, the circulation pump 71 and the circulation pump 73 are driven by the control unit, and the flowing water switching valve 44 is controlled, so that the bath recuperation heat exchange is performed from the flowing water switching valve 44. Heat exchange is performed between the hot water flowing into the vessel 72 and the bath water flowing from the bathtub 74 through the bath water retreating path 75 into the bath recuperation heat exchanger 72. That is, in the bath circuit 7, the bath water stored in the bathtub 74 is heated (reheated) using the hot water heated by the water heat exchanger 32 and flowing on the flowing water path 30 d as a heat medium. In addition, it is possible to use heating means such as a floor heating device or a bathroom dryer instead of the bath circuit 7 as another embodiment.

Next, the configuration of each of the CO ₂ cycle 1 and the R410A cycle 2 will be described.
The CO ₂ cycle 1 includes a refrigerant circulation path 10 that connects the compressor 11, the water heat exchanger 32, the expander 12, the outdoor air heat exchanger 13, and the compressor 11 in this order. . Here, in the compressor 11, the CO ₂ refrigerant is compressed and discharged at a pressure higher than that of the R410A refrigerant.
In the refrigerant circulation path 10, the CO ₂ refrigerant is circulated in the direction of the arrow shown in the figure by driving the compressor 11 by the control unit (not shown). Thus, in the CO ₂ cycle 1, the high-temperature and high-pressure CO ₂ refrigerant compressed and discharged in the compressor 11 is heat-exchanged with the water flowing on the flowing water path 30 c in the water heat exchanger 32. After cooling, it expands in the expander 12. Thereafter, the low-temperature and low-pressure CO ₂ refrigerant expanded in the expander 12 is heat-exchanged with the outdoor air in the outdoor air heat exchanger 13 to absorb heat and vaporize, and then flows into the compressor 11 again. In addition, since the flow direction of the CO ₂ refrigerant and water in the water heat exchanger 32 is opposite, heat exchange between the CO ₂ refrigerant and water is performed efficiently.

On the other hand, the R410A cycle 2 includes refrigerant circulation paths 81 to 83 through which the R410A refrigerant is circulated.
The refrigerant circulation path 81 includes the compressor 21, the four-way valve 24, the refrigerant switching valves 51 and 52, the water heat exchanger 32, the expander 22a, the refrigerant switching valves 53 and 54, the outdoor air heat exchanger 13, and the refrigerant switching. The valve 56, the four-way valve 24, and the compressor 21 are connected in order.
In the compressor 21, the R410A refrigerant is compressed and discharged at a pressure lower than that of the CO ₂ refrigerant.
On the other hand, the output of the compressor 21 is configured to be higher in output than the compressor 11. Thus, the instantaneous heating capability in the R410A cycle 2 can be increased by configuring the compressor 21 so as to be capable of high output. For example, it is possible to obtain high hot water supply performance and air conditioning performance by demonstrating high heating capability in the instantaneous hot water supply operation and air conditioning operation described later.
By the way, although the compressor 11 is configured to be capable of high output, the pressure resistance performance required for the compressor 21 is lower than the pressure resistance performance required for the compressor 11. Compared to the case where output is possible, the increase in the size and cost of the heat pump type water heater X is suppressed.

In the refrigerant circulation path 81, the high-temperature and high-pressure R410A refrigerant compressed and discharged by the compressor 21 reaches the water heat exchanger 32 via the four-way valve 24 and the refrigerant switching valves 51 and 52. The R410A refrigerant is cooled by exchanging heat with water flowing on the flowing water path 30c in the water heat exchanger 32. Thereafter, the R410A refrigerant expands in the expander 22a. The low-temperature and low-pressure R410A refrigerant expanded in the expander 22a is heat-exchanged with the outdoor air in the outdoor air heat exchanger 13 through the refrigerant switching valves 53 and 54, and then absorbed and vaporized. It flows into the compressor 21 again through the valve 56 and the four-way valve 24.
In the R410A cycle 2, as described above, the R410A refrigerant is circulated in the refrigerant circulation path 81, so that water flowing in the direction of the arrow on the flowing water path 30c is changed to the R410A refrigerant in the water heat exchanger 32. It is heated to about 65 ° C. by heat exchange. Since the flow direction of the R410A refrigerant and water in the water heat exchanger 32 is opposite, heat exchange between the R410A refrigerant and water is performed efficiently.

The refrigerant circulation path 82 includes the compressor 21, the four-way valve 24, the refrigerant switching valves 56 and 52, the water heat exchanger 32, the expander 22a, the refrigerant switching valves 53 and 55, and indoor air heat. The exchanger 4, the refrigerant switching valve 51, the four-way valve 24, and the compressor 21 are connected in order. The refrigerant circulation path 82 is used when hot water supply and cooling are performed simultaneously.
The indoor air heat exchanger 4 is provided in an air conditioner (not shown) that heats and cools the room indoors, and performs heat exchange between the R410A refrigerant circulated in the R410A cycle 2 and room air. Air is heated or cooled.
In the refrigerant circulation path 82, the high-temperature and high-pressure R410A refrigerant compressed and discharged by the compressor 21 reaches the water heat exchanger 32 through the four-way valve 24 and the refrigerant switching valves 56 and 52. The R410A refrigerant is cooled by exchanging heat with water flowing on the flowing water path 30e in the water heat exchanger 32. Thereafter, the R410A refrigerant expands in the expander 22a. The low-temperature and low-pressure R410A refrigerant expanded in the expander 22a is heat-exchanged with the indoor air in the indoor air heat exchanger 4 through the refrigerant switching valves 53 and 55, and absorbs and vaporizes. It flows into the compressor 21 again through the valve 51 and the four-way valve 24.
In the R410A cycle 2, the R410A refrigerant is circulated through the refrigerant circulation path 82 as described above, so that water flowing in the direction of the arrow on the flowing water path 30c becomes the R410A refrigerant in the water heat exchanger 32. It is heated to about 65 ° C. by heat exchange. Since the flow direction of the R410A refrigerant and water in the water heat exchanger 32 is opposite, heat exchange between the R410A refrigerant and water is performed efficiently.
Further, in the indoor air heat exchanger 4, the indoor air is cooled by the heat exchange between the R410A refrigerant and the indoor air, so that the indoor cooling is realized. That is, in the refrigerant circulation path 82, hot water can be supplied using the exhaust heat of the cooling in the indoor air heat exchanger 4 without using the outdoor air heat exchanger 13.

On the other hand, the refrigerant circulation path 83 includes the compressor 21, the four-way valve 24, the refrigerant switching valve 51, the indoor air heat exchanger 4, the refrigerant switching valve 55, the expander 22b, the refrigerant switching valve 54, The outdoor air heat exchanger 13, the refrigerant switching valve 56, the four-way valve 24, and the compressor 21 are connected in order.
In the R410A cycle 2, the R410A refrigerant is circulated in the direction of the solid arrow shown in the refrigerant circulation path 83 to perform the heating operation, and the refrigerant is circulated in the direction of the broken arrow to show the cooling operation. This will be specifically described below.

(1) About the heating operation When the user requests the heat pump type hot water heater X to start the heating operation from the operation unit (not shown), the heat pump type hot water heater X is controlled by the control unit (not shown). The compressor 21 and the four-way valve 24 are controlled, and circulation of the R410A refrigerant in the direction of the solid arrow in the refrigerant circulation path 83 of the R410A cycle 2 is started. At this time, the illustrated solid line path is established inside the four-way valve 24.
Specifically, the high-temperature and high-pressure R410A refrigerant compressed and discharged by the compressor 21 reaches the indoor air heat exchanger 4 through the four-way valve 24 and the refrigerant switching valve 51. The R410A refrigerant is cooled by heat exchange with indoor air in the indoor air heat exchanger 4. Thereafter, the R410A refrigerant expands in the expander 22b through the refrigerant switching valve 55. The low-temperature and low-pressure R410A refrigerant expanded in the expander 22b is subjected to heat exchange with the outdoor air in the outdoor air heat exchanger 13 through the refrigerant switching valve 54, and absorbs and vaporizes the refrigerant. Then, it flows into the compressor 21 again.
In the R410A cycle 2, the R410A refrigerant is circulated in the direction of the solid arrow in the refrigerant circulation path 83 as described above, so that indoor air exchanges heat with the R410A refrigerant in the indoor air heat exchanger 4. Heated by. That is, heating is realized by the heat pump type hot water heater X.

(2) Cooling operation When the user requests the heat pump water heater X to start the cooling operation from an operation unit (not shown), the heat pump water heater X has the control unit (not shown). ), The compressor 21 and the four-way valve 24 are controlled, and the circulation of the R410A refrigerant in the direction of the broken line arrow is started in the refrigerant circulation path 83 of the R410A cycle 2. At this time, the illustrated broken line path is established inside the four-way valve 24.
Specifically, the high-temperature and high-pressure R410A refrigerant compressed and discharged by the compressor 21 reaches the outdoor air heat exchanger 13 through the four-way valve 24 and the refrigerant switching valve 56. The R410A refrigerant is cooled by exchanging heat with outdoor air in the outdoor air heat exchanger 13. Thereafter, the R410A refrigerant expands in the expander 22b via the refrigerant switching valve 54. The low-temperature and low-pressure R410A refrigerant expanded in the expander 22b is heat-exchanged with the indoor air in the indoor air heat exchanger 4 through the refrigerant switching valve 55 to absorb heat and vaporize, and then the refrigerant switching valve. 51, it flows into the compressor 21 again through the four-way valve 24.
In the R410A cycle 2, the R410A refrigerant is circulated in the refrigerant circulation path 83 in the direction of the broken line arrow as described above, so that the indoor air exchanges heat with the R410A refrigerant in the indoor air heat exchanger 4. Cooled by. That is, cooling is realized by the heat pump type hot water heater X.

Further, in the heat pump type hot water heater X, the respective components are controlled by the control unit (not shown), whereby the water supplied from the water supply port is heated by the water heat exchanger 32 to be supplied from the hot water supply port. An instantaneous hot water supply operation for directly supplying hot water or a hot water storage operation in which water supplied from the hot water storage tank 31 is heated by the water heat exchanger 32 and returned to the hot water storage tank 31 is performed.
In the heat pump type hot water heater X according to the embodiment of the present invention, the CO ₂ cycle 1 is mainly used for the hot water storage operation, and the R410A cycle 2 is mainly used for the instantaneous hot water supply operation. Hereinafter, the hot water storage operation and the instantaneous hot water supply operation will be described.

(1) Hot water storage operation In the hot water storage operation, instantaneous high heating capacity is not required, and water in the storage tank 31 may be gradually heated. Therefore, when the hot water storage operation is performed, the CO ₂ cycle 1 is Operated by the control unit. As a result, the CO ₂ refrigerant is circulated in the CO ₂ cycle 1.
Then, the circulation pump 34 is driven by the control unit, and the flowing water switching valves 41 and 42 are controlled, so that the water supplied from the hot water storage tank 31 flows into the flowing water paths 30a, 30c, 30d, and the hot water storage tank. Hot water is circulated in the order of 31. Thereby, the hot water heated by the heat exchange with the CO ₂ refrigerant in the water heat exchanger 32 on the flowing water path 30 c is stored in the hot water storage tank 31. At this time, since the hot water stored in the hot water storage tank 31 is hot water having a high temperature of, for example, about 90 ° C. heated by heat exchange with the CO ₂ refrigerant, the size of the hot water storage tank 31 can be reduced. .

(2) Instantaneous hot water supply operation On the other hand, in the instantaneous hot water supply operation, instantaneously high heating capacity is required to obtain a sufficient hot water supply temperature and amount of hot water supply, so the compressor 21 capable of high output is provided. The R410A cycle 2 is operated. Thus, the R410A refrigerant is circulated through the refrigerant circulation path 81 of the R410A cycle 2.
And by the said control part controlling the said flowing water switching valves 41 and 42, the water supplied from the said water supply port distribute | circulates in the order of the said water flow path 30b, 30c, 30d, and the said hot water supply port. Thereby, the hot water heated by the heat exchange with the R410A refrigerant in the water heat exchanger 32 on the flowing water path 30c is directly supplied from the hot water supply port. At this time, since the compressor 21 of the R410A cycle 2 can output higher than the compressor 11 of the CO ₂ cycle 1, it can exhibit a high heating capacity.
In addition, as described above, the pressure resistance required for the compressor 21 may be lower than the pressure resistance required for the compressor 11, so that the compressor 11 is configured to be capable of high output. Thus, an increase in device size and an increase in cost can be suppressed, and consequently an increase in size and an increase in cost of the heat pump hot water heater X can be suppressed.

  However, a sufficient amount of heating by the water heat exchanger 32 cannot be obtained for a certain time after the instantaneous hot water supply operation is started. Therefore, until a certain amount of time has elapsed from the start of the instantaneous hot water supply operation, the hot water stored in the hot water storage tank 31 passes through the flowing water path 30h and flows from the water supply port to the flowing water path. The temperature is adjusted by mixing with water supplied through 30i and then supplied to the hot water supply port. Thereby, hot water can be instantaneously supplied from the hot water supply port. Then, when the water heat exchanger 32 can sufficiently heat the water, the water supply from the hot water storage tank 31 is stopped, and thereafter the instantaneous hot water supply operation is performed. In addition, it is also possible to supply hot water as it is, without mixing the hot water stored in the hot water storage tank 31 with the water supplied from the water supply port.

Moreover, in the heat pump type hot water heater X, the instantaneous hot water supply operation and the air conditioning operation can be executed simultaneously.
(1) Simultaneous operation of heating and instantaneous hot water supply During simultaneous operation of heating and instantaneous hot water supply, in the R410A cycle 2, the control unit (not shown) performs the compressor 21, the four-way valve 24, and the refrigerant switching valve. By controlling 51 to 56, the R410A refrigerant is circulated in the direction of the solid arrow shown in FIG.
Specifically, in the refrigerant circulation path 81, the R410A refrigerant is converted into the compressor 21, the four-way valve 24, the refrigerant switching valve 51, the refrigerant switching valve 52, the water heat exchanger 32, the expander 22a, the refrigerant switching valve 53, The refrigerant switching valve 54, the outdoor air heat exchanger 13, the refrigerant switching valve 56, the four-way valve 24, and the compressor 21 are circulated in this order. Thereby, the water flowing on the flowing water path 30b is heated in the water heat exchanger 32.
On the other hand, in the refrigerant circulation path 83, the R410A refrigerant flows into the compressor 21, four-way valve 24, refrigerant switching valve 51, indoor air heat exchanger 4, refrigerant switching valve 55, expander 22b, refrigerant switching valve 54, outdoor air. The heat exchanger 13, the refrigerant switching valve 56, the four-way valve 24, and the compressor 21 are circulated in this order. Thereby, in the said indoor air heat exchanger 4, indoor air is heated and heating is performed.
Thus, in the R410A cycle 5, heating and instantaneous hot water supply are performed simultaneously by distributing the R410A refrigerant by the refrigerant switching valve 51.

(2) Simultaneous operation of cooling and instantaneous hot water supply During simultaneous operation of cooling and instantaneous hot water supply, in the R410A cycle 2, the control unit (not shown) causes the compressor 21, the four-way valve 24, and the refrigerant switching valve 51 to operate. By controlling .about.56, the R410A refrigerant is circulated in the direction of the broken arrow shown in FIG.
Specifically, in the refrigerant circulation path 81, the R410A refrigerant is supplied from the compressor 21, the four-way valve 24, the refrigerant switching valves 56 and 52, the water heat exchanger 32, the expander 22a, the refrigerant switching valve 53, and the refrigerant switching valve. 55, the indoor air heat exchanger 4, the refrigerant switching valve 51, the four-way valve 24, and the compressor 21 are circulated in this order. Thereby, the water flowing on the flowing water path 30b is heated in the water heat exchanger 32.
On the other hand, in the refrigerant circulation path 83, the R410A refrigerant flows into the compressor 21, the four-way valve 24, the refrigerant switching valve 56, the outdoor air heat exchanger 13, the refrigerant switching valve 54, the expander 22b, the refrigerant switching valve 55, the indoor air. The heat exchanger 4, the refrigerant switching valve 51, the four-way valve 24, and the compressor 21 are circulated in this order. As a result, the indoor air heat exchanger 4 cools the room air by cooling it.
As described above, in the R410A cycle 2, the refrigerant switching valve 56 distributes the R410A refrigerant so that cooling and instantaneous hot water supply are performed simultaneously.

Here, when the instantaneous hot water supply operation and the cooling / heating operation are simultaneously performed using the R410A cycle 2 as described above, the heating capacity of the R410A cycle 2 is used in a distributed manner. There is a possibility that the amount of hot water supply cannot be obtained.
Therefore, in the heat pump type hot water heater X, the R410A cycle 2 is preferentially used in the instantaneous hot water supply operation. When the heating load is higher than a predetermined heating load at which a sufficient hot water supply temperature or hot water supply amount cannot be obtained in the instantaneous hot water supply operation, the control unit (not shown) drives the compressor 11 of the CO ₂ cycle 1. And the circulation of the CO ₂ refrigerant in the CO ₂ cycle 1 is started. That is, the R410A cycle 2 and the CO ₂ cycle 1 are operated simultaneously. Whether or not the R410A refrigerant and the CO ₂ refrigerant are operated simultaneously is determined based on, for example, the difference between the set temperature of the air conditioner and the room temperature, the hot water supply temperature of the instantaneous hot water supply, the amount of hot water supply, and the like. This is done by the control unit.
Thereby, in the water heat exchanger 32, water is heated by both the R410A refrigerant and the CO ₂ refrigerant. That is, a decrease in the heating efficiency of water during the simultaneous operation of instantaneous hot water supply and cooling / heating in the R410A cycle 1 is compensated by heat exchange between the CO ₂ refrigerant circulated in the CO ₂ cycle 1 and water. Therefore, when performing instantaneous hot water supply and cooling / heating at the same time in the R410A cycle 2, sufficient hot water supply temperature and hot water supply amount can be obtained.
Further, in the present embodiment, the case where the instantaneous hot water supply operation and the cooling / heating operation are performed simultaneously has been described as an example. For example, the R410A refrigerant and the CO ₂ refrigerant according to the operating state of the bath circuit 7 It may be determined whether or not both are operated. Furthermore, when the R410A cycle 2 is also used for a floor heating device or a bathroom dryer (not shown), the heating load of the R410A cycle 2 differs depending on the operation status, so that these operation statuses It is desirable to determine whether or not to operate both the R410A refrigerant and the CO ₂ refrigerant in consideration of the above.

1 is a schematic configuration diagram of a heat pump type water heater X according to an embodiment of the present invention.

Explanation of symbols

1 ... heat pump cycle (an example of a first heat pump cycle)
2 ... Heat pump cycle (an example of a second heat pump cycle)
4 ... Indoor air heat exchanger 7 ... Bath circuit 11, 21 ... Compressor 12, 22a, 22b ... Expander 13 ... Outdoor air heat exchanger 24 ... Four-way valve 30a-30i ... Flow path 31 ... Hot water storage tank 32 ... Water heat Exchanger 34 ... circulation pumps 41-45 ... flowing water switching valves 51-56 ... refrigerant switching valves 81-83 ... refrigerant circulation path

Claims (8)

A first heat pump cycle in which a first refrigerant is circulated through at least a first compressor and a first expander;
A second heat pump cycle in which a second refrigerant having a pressure lower than that of the first refrigerant is circulated through at least a second compressor and a second expander;
A water heat exchanger for exchanging heat between the first refrigerant and / or the second refrigerant and water;
A hot water storage tank for storing hot water heated by the water heat exchanger;
With
The first heat pump cycle is operated at the time of executing a hot water storage operation in which hot water heated by the water heat exchanger is stored in the hot water storage tank;
The heat pump type hot water heater, wherein the second heat pump cycle is operated during execution of an instantaneous hot water supply operation in which hot water heated by the water heat exchanger is supplied from a predetermined hot water supply port.   The heat pump type hot water heater according to claim 1, wherein the first refrigerant is a carbon dioxide refrigerant, and the second refrigerant is an HFC refrigerant. A common outdoor air heat exchanger for exchanging heat between the first refrigerant and the second refrigerant and outdoor air;
The heat exchange area where heat is exchanged between the second refrigerant and outdoor air in the outdoor air heat exchanger is greater than the heat exchange area where heat is exchanged between the first refrigerant and outdoor air. The heat pump type water heater according to claim 1, wherein the heat pump type water heater is also in a large relationship.   The heat pump type according to claim 3, wherein a pipe through which the second refrigerant flows in the outdoor air heat exchanger has a longer relationship than a pipe through which the first refrigerant flows in the outdoor air heat exchanger. Water heater. The water heat exchanger is a common water heat exchanger that exchanges heat between the first refrigerant and the second refrigerant and water,
In the water heat exchanger, the heat exchange area where heat exchange is performed between the second refrigerant and water is larger than the heat exchange area where heat exchange is performed between the first refrigerant and water. The heat pump type water heater according to any one of claims 1 to 4.   The heat pump type water heater according to claim 5, wherein a pipe through which the second refrigerant flows in the water heat exchanger has a longer relationship than a pipe through which the first refrigerant flows in the water heat exchanger. .   The first heat pump cycle is operated together on the condition that the heating load of the second heat pump cycle at the time of execution of the instantaneous hot water supply operation is not less than a predetermined magnitude. The heat pump type water heater described in 1.   The heat pump type hot water heater according to any one of claims 1 to 7, wherein the second heat pump cycle is shared by any one or more of an air conditioner, a bath circuit, and a floor heating device.

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