WARM WATER UNIT AND HEAT PUMP SYSTEM HAVING THE SAME

Abstract

 A warm water unit 2 includes: a water refrigerant heat exchanger 4 through which high pressure side combustible refrigerant of a heat pump cycle and heat medium flow together, and in which the combustible refrigerant and the heat medium exchange heat therebetween to produce warm water; a first space 2e formed of a plurality of exterior bodies 2a; and a second space 2f formed of a non-breathable member 2d and the exterior bodies 2a and provided in the first space 2e, wherein the water refrigerant heat exchanger 4 is placed in the second space 2f. Even if combustible refrigerant leaks from the water refrigerant heat exchanger 4, it is possible to prevent the combustible refrigerant from permeating and accumulating in the entire warm water unit 2.

Description

[TECHNICAL FIELD]

[0001] The present disclosure relates to a warm water unit and a heat pump system having the same.

[BACKGROUND TECHNIQUE]

[0002] Patent document 1 discloses an appearance configuration of a unit provided with a water refrigerant heat exchanger therein. The water refrigerant heat exchanger is covered with an exterior body.

[0003] The exterior body is formed by a front plate which forms a front surface, an exterior box which forms an upper portion and left and right sides, and a substrate which forms a bottom portion and a back surface.

[PRIOR ART DOCUMENT]

[PATENT DOCUMENT]

[0004] [Patent Document 1] Japanese Patent Application Laid-open No.2010-117109

[SUMMARY OF THE INVENTION]

[PROBLEM TO BE SOLVED BY THE INVENTION]

[0005] The present disclosure provides a warm water unit and a heat pump system having the same in which even if combustible refrigerant leaks from the water refrigerant heat exchanger, it is possible to prevent combustible refrigerant from permeating or accumulating in an entire interior of the warm water unit.

[MEANS FOR SOLVING THE PROBLEM]

[0006] A warm water unit of the present disclosure includes: a water refrigerant heat exchanger through which high pressure side combustible refrigerant of a heat pump cycle and heat medium flow together, and in which the combustible refrigerant and the heat medium exchange heat therebetween to produce warm water; a first space formed of a plurality of exterior bodies; and a second space formed of a non-breathable member and the exterior bodies and provided in the first space, wherein the water refrigerant heat exchanger is placed in the second space.

[EFFECT OF THE INVENTION]

[0007] According to the warm water unit and the heat pump system having the same, even if combustible refrigerant leaks from the water refrigerant heat exchanger, it is possible to prevent combustible refrigerant from permeating or accumulating in an entire interior of the warm water unit.

[BRIEF DESCRIPTION OF DRAWINGS]

[0008] 

Fig. 1 is a circuit configuration diagram of a heat pump system in an embodiment of the present invention;

Fig. 2 is a diagram showing a connection configuration of the heat pump system;

Fig. 3 is a perspective view of a top surface of a warm water unit of the heat pump system;

Fig. 4 is a side sectional view of the warm water unit of the heat pump system; and

Fig. 5(a) is an interior perspective view of the warm water unit of the heat pump system of the embodiment, and Fig. 5(b) is a perspective view of a pipe mounting member of the warm water unit.

[MODE FOR CARRYING OUT THE INVENTION]

(Knowledge and the like which become a basis of the present disclosure)

[0009] When inventors of the present invention led to this disclosure, in a technique in which water and high pressure-side refrigerant of a heat pump cycle flow together and they exchanged heat with each other to provide warm water, it was general to design a manufactured product in which a water refrigerant heat exchanger was covered with an exterior body.

[0010] Under such condition, the inventors found that when combustible refrigerant was used as refrigerant, if the combustible refrigerant leaked from the water refrigerant heat exchanger, the combustible refrigerant permeated the unit in which the water refrigerant heat exchanger was provided, and as the interior of the unit was narrower, gas concentration became higher, and there was a problem that the water refrigerant heat exchanger faced an increased risk such as ignition. To solve the problem, the inventors configured a subject matter of the present disclosure.

[0011] Hence, the present disclosure provides a warm water unit and a heat pump system having the same capable of preventing combustible refrigerant from permeating or accumulating in an entire interior of the warm water unit even if the combustible refrigerant leaks from a water refrigerant heat exchanger.

[0012] An embodiment of the present invention will be described below in detail while referring to the drawings. Description which is more detailed than necessary is omitted in some cases. For example, detailed description of a matter which is already well known, or duplicate description of substantially the same configuration are omitted in some cases.

[0013] The accompanying drawings and the following description are provided so that a person skilled in the art can sufficiently understand the present disclosure, and they are not intended to limit a subject matter described in the patent claims.

(Embodiment)

[1-1. Configuration]

[0014] Fig. 1 is a circuit configuration diagram of a heat pump system in an embodiment of the present invention. The heat pump system of the embodiment includes a heat pump unit 1 placed outdoors, and a warm water unit 2 placed indoors.

[0015] The warm water unit 2 is connected to a heating terminal 19 through a heat medium pipe 20. Further, a water supply pipe 31 for supplying water from a water pipe or the like to the warm water unit 2, and a hot water-discharging pipe 30 for supplying warm water to a hot water supply terminal 33 are connected to the warm water unit 2.

[0016] Fig. 2 is a diagram showing a connection configuration of the heat pump system in the embodiment. The heat pump unit 1 and the warm water unit 2 of the heat pump system are connected to each other through a first refrigerant pipe 8c and a second refrigerant pipe 8d.

[0017] Further, the heat pump unit 1 and the warm water unit 2 are connected to each other through an electric wiring 18. A control signal is transmitted from a control device 21 provided in the warm water unit 2 to the heat pump unit 1 through the electric wiring 18.

[0018] The warm water unit 2 and the heating terminal 19 (e.g., floor heating) are connected to each other through the heat medium pipe 20. The hot water-discharging pipe 30 is connected to the warm water unit 2. Warm water is supplied to the hot water supply terminal 33 through the hot water-discharging pipe 30.

[0019] The water supply pipe 31 is connected to the warm water unit 2. Water is supplied to the hot water tank 15 through the water supply pipe 31.

[0020] The heat pump unit 1 includes a compressor 3 which compresses refrigerant and discharges high temperature refrigerant, a decompressor 5 which decompresses the refrigerant, an evaporator 6a which exchanges heat between air and the refrigerant, and a four-way valve 7 which changes a flow path of the refrigerant.

[0021] The compressor 3, the decompressor 5, the evaporator 6a and the four-way valve 7 are connected to one another through a refrigerant pipe 8. An electromagnetic expansion valve or a capillary tube is used as the decompressor 5. A blower fan 6b which sends air to the evaporator 6a and promotes heat exchange between air and the refrigerant is provided with the heat pump unit 1. The compressor 3, the decompressor 5, the evaporator 6a, the blower fan 6b and the four-way valve 7 are provided in the heat pump unit 1.

[0022] A water refrigerant heat exchanger 4 is placed in the warm water unit 2. The water refrigerant heat exchanger 4 exchanges heat between heat medium and high temperature refrigerant, and produces high temperature heat medium. The water refrigerant heat exchanger 4 is connected annularly by the compressor 3, the decompressor 5, the evaporator 6a, the four-way valve 7 and the refrigerant pipe 8, and constitutes a heat pump cycle.

[0023] A plate-type heat exchanger can be used as the water refrigerant heat exchanger 4 for example. As the water refrigerant heat exchanger 4, it is possible to use a double pipe-type heat exchanger having a refrigerant pipe provided in the heat medium pipe 20 through which heat medium flows. Refrigerant flows through the refrigerant pipe of the double pipe-type heat exchanger. Water or antifreeze liquid can be used as the heat medium.

[0024] The water refrigerant heat exchanger 4 is placed in the warm water unit 2, and the four-way valve 7 and the decompressor 5 are placed in the heat pump unit 1. The water refrigerant heat exchanger 4 and the four-way valve 7 are connected to each other through the first refrigerant pipe 8c. The water refrigerant heat exchanger 4 and the decompressor 5 are connected to each other through the second refrigerant pipe 8d. The heat pump unit 1 is placed outdoors, and the warm water unit 2 placed indoors.

[0025] Combustible refrigerant is used as refrigerant which circulates through the heat pump unit 1 and the warm water unit 2. In this embodiment, "combustible refrigerant" includes slightly flammable refrigerant in addition to the combustible refrigerant.

[0026] That is, as the refrigerant which circulates through the heat pump unit 1 and the warm water unit 2, R32 which is slightly flammable refrigerant, mixed refrigerant including 65wt% or more R32, or HFO-based mixed refrigerant is used, but R290 may also be used for example. These refrigerants are combustible refrigerant having density greater than air under atmospheric pressure.

[0027] The hot water tank 15 in which high temperature warm water is stored is placed in the warm water unit 2. The hot water tank 15 is covered with heat insulating material such as foam material. According to this, heat retaining property of water stored in the hot water tank 15 is enhanced.

[0028] The water refrigerant heat exchanger 4 is placed in the warm water unit 2. The water refrigerant heat exchanger 4 produces high temperature heat medium by heat radiation of the refrigerant. A heat medium path 12a through which heat medium flows is provided in the warm water unit 2. The heat medium path 12a includes a bypass path 12b. The bypass path 12b branches off from a three-way valve 16 provided in the heat medium path 12a, and the bypass path 12b is connected to the heat medium path 12a through a heat exchanger 15a which is provided in the hot water tank 15. The heat medium path 12a is located upstream of the three-way valve 16.

[0029] The heat medium path 12a is connected to the heating terminal 19 through a first heating connection 20a and a second heating connection 20b, and the heat medium path 12a constitutes a heat medium circuit 12. The heat medium path 12a connects the first heating connection 20a and the second heating connection 20b to each other. Heat medium flows into the first heating connection 20a from outside of the warm water unit 2. Heat medium flows out into the second heating connection 20b from inside of the warm water unit 2.

[0030] The heat medium path 12a is provided with a circulation pump 9, the water refrigerant heat exchanger 4, a heating portion 14 and the three-way valve 16 in this order from an upstream side of a flowing direction of heat medium (from the side of the first heating connection 20a). The heat medium path 12a is provided with a flow switch 10, an overpressure relief valve 11, an expansion tank 13, an air vent valve 17 and a pressure indicator 23.

[0031] The flow switch 10 detects a flow of warm water. The flow switch 10 is placed downstream of the circulation pump 9 and the water refrigerant heat exchanger 4. That is, the flow switch 10 is placed at a location where heat medium after it exchanges heat in the water refrigerant heat exchanger 4 flows. By placing the flow switch 10 downstream of the circulation pump 9, it is possible to detect an operating state of the circulation pump 9.

[0032] In this embodiment, the flow switch 10 is provided in the heat medium pipe 20 between the water refrigerant heat exchanger 4 and the heating portion 14. The flow switch 10 may detect a flow rate of the heat medium which flows through the heat medium circuit 12.

[0033] In this embodiment, a DC pump is used as the circulation pump 9. When the heat pump system is installed, it is necessary to set, within a predetermined scope, the flow rate of the heat medium which flows through the heat medium circuit 12 in accordance with a size or radiation amount of the heating terminal 19 provided in the heat medium circuit 12.

[0034] This setting operation is carried out by a remote controller 22 when the heat pump system is installed. In this embodiment, a circulation amount of the heat medium caused by the circulation pump 9 can be set by selecting from seven stages by the remote controller 22.

[0035] The heat medium circuit 12 is provided with the heating portion 14. The heating portion 14 includes electric heating means (heater) placed in a case forming a flow path through which heat medium flows. By flowing the heat medium through the heating portion 14, the heat medium is heated to predetermined temperature by the heater.

[0036] The heating portion 14 can be used when outside air temperature is low and the heating ability of the heat pump cycle is lowered and when the heat medium cannot be heated sufficiently by heat radiation of the refrigerant in the water refrigerant heat exchanger 4. The heating portion 14 can be used also when the heat pump cycle has a breakdown.

[0037] The heat medium path 12a is provided with the expansion tank 13 and the overpressure relief valve 11 which adjust pressure. By heating the heat medium by the water refrigerant heat exchanger 4, if a volume of the heat medium in the heat medium circuit 12 is expanded, the heat medium of an amount of the expanded volume is absorbed by the expansion tank 13.

[0038] When internal pressure of the heat medium circuit 12 rises to predetermined pressure or higher, the heat medium in the heat medium circuit 12 can be discharged to outside of the heat medium circuit 12 by the overpressure relief valve 11. In this embodiment, the expansion tank 13 is provided in the heat medium pipe 20 located downstream of the three-way valve 16. The overpressure relief valve 11 is mounted on the heating portion 14.

[0039] The heat medium circuit 12 in the warm water unit 2 is provided with the air vent valve 17. The air vent valve 17 has a function to automatically discharge air accumulated in the air vent valve 17 to outside. Therefore, by placing the air vent valve 17 in the heat medium circuit 12, air remaining in the heat medium circuit 12 can be discharged to outside of the heat medium circuit 12.

[0040] The air vent valve 17 is provided at the highest position of the heat medium path 12a. Since air in the heat medium circuit 12 accumulates at the high position in the heat medium circuit 12 by its buoyancy force, air in the heat medium circuit 12 can easily be vented by providing the air vent valve 17 at the highest position of the heat medium circuit 12. The heat medium path 12a is provided with the pressure indicator 23. According to this, it is possible to check the pressure in the heat medium circuit 12.

[0041] The bypass path 12b constituting a portion of the heat medium circuit 12 is provided in the warm water unit 2. The bypass path 12b branches off from the three-way valve 16. The bypass path 12b is connected to the heat medium path 12a between the first heating connection 20a and the circulation pump 9 through the heat exchanger 15a provided in the hot water tank 15.

[0042] The heat medium path 12a located downstream of the heating portion 14 is provided with the three-way valve 16. The three-way valve 16 can switch between a flow of the heat medium heated by the water refrigerant heat exchanger 4 to the hot water tank 15 and a flow of the heat medium to the downstream side of the heat medium path 12a.

[0043] According to this, if the heat medium is made to flow to the hot water tank 15, it is possible to heat water stored in the hot water tank 15 by the heat exchanger 15a. If the heat medium is made to flow to the downstream side of the heat medium path 12a, it is possible to flow the heat medium to the heating terminal 19 (e.g., heating terminal) provided in the heat medium circuit 12 outside of the warm water unit 2, and the heating operation can be carried out.

[0044] The three-way valve 16 may adjust a flow rate of heat medium which flows out from the water refrigerant heat exchanger 4 to a flow rate of heat medium which flows to the hot water tank 15 and a flow rate of heat medium which flows to the downstream side of the heat medium path 12a.

[0045] Heat medium which flows through the bypass path 12b flows in from a connection port 15b located at a relatively upper side in a height direction of the hot water tank 15, and heat medium after it exchanges heat in the heat exchanger 15a flows out from a connection port 15c located at a relatively lower side in the height direction of the hot water tank 15. According to this, it is possible to efficiently heat water in the hot water tank 15.

[0046] The water supply pipe 31 through which water from a water pipe or the like flows is connected to the hot water tank 15. Water from the water pipe or the like flows into a lower portion of the hot water tank 15 through a pressure reducing valve 32 and a first hot water supply connection 30a provided in the warm water unit 2.

[0047] The hot water-discharging pipe 30 through which water (warm water) in the hot water tank 15 flows out is connected to the hot water tank 15 at a location higher than the water supply pipe 31. Water (warm water) in the hot water tank 15 flows out into the hot water-discharging pipe 30 from an upper portion of the hot water tank 15.

[0048] Thereafter, the water (warm water) flows to the outside of the warm water unit 2 from a second hot water supply connection 30b, and the water is supplied to the hot water supply terminal 33 such as a faucet or a shower. A mixing faucet 34 which mixes water from the water supply pipe 31 and warm water from the hot water-discharging pipe 30 is provided at an upstream side of the hot water supply terminal 33.

[0049] In this embodiment, heat medium is heated in the water refrigerant heat exchanger 4, and the heated heat medium is made to flow to the heat exchanger 15a. According to this, water in the hot water tank 15 is heated. That is, water in the hot water tank 15 is indirectly heated through heat medium using heat of refrigerant which circulates through the heat pump cycle.

[0050] That is, water which flowed through the water supply pipe 31 is heated by the heat medium stored in the hot water tank 15 while the water flows through the heat exchanger 15a, the water flows out from the hot water-discharging pipe 30, and the water is supplied to the hot water supply terminal 33. According to this, if high temperature heat medium is stored in the hot water tank 15, when warm water is required by the hot water supply terminal 33, it is possible to heat water by the heat exchanger 15a and supply the water to the hot water supply terminal 33.

[0051] The first heating connection 20a and the second heating connection 20b provided in the warm water unit 2 are connected to the heating terminal 19 such as a radiator and a floor heating panel through the heat medium pipe 20. According to this, the heat medium path 12a constitutes the heat medium circuit 12. The first heating connection 20a and the second heating connection 20b are detachably connected to the heat medium pipe 20.

[0052] Fig. 3 is a perspective view of a top surface of the warm water unit of the heat pump system in this embodiment.

[0053] Fig. 3 shows the first refrigerant pipe 8c and the second refrigerant pipe 8d. Combustible refrigerant compressed by the compressor 3 of the heat pump unit 1 flows to the water refrigerant heat exchanger 4 of the warm water unit 2 through the first refrigerant pipe 8c. Combustible refrigerant after heat medium is heated by the water refrigerant heat exchanger 4 and the combustible refrigerant radiates heat flows to the decompressor 5 of the heat pump unit 1 through the second refrigerant pipe 8d.

[0054]  The first refrigerant pipe 8c and the second refrigerant pipe 8d connect the heat pump unit 1 and the warm water unit 2 to each other through a first connection 8a and a second connection 8b.

[0055] The warm water unit 2 includes a recess 2b. In a plurality of exterior bodies 2a which form the warm water unit 2, the recess 2b is recessed in a depth direction of any one of elevation surfaces including a front surface, a side surface and a rear surface, and the recess 2b is recessed downward from the top surface. The first connection 8a and the second connection 8b are placed in the recess 2b.

[0056] Fig. 4 is a side sectional view of the warm water unit of the heat pump system in the embodiment. Figs. 5 are interior perspective views of the warm water unit of the heat pump system of the embodiment.

[0057] In Figs. 2 and 4, the plurality of exterior bodies 2a which form an outer bailey of the warm water unit 2 are the top surface and a bottom surface and the elevation surfaces composed of the front surface, the side surface and the rear surface. These surfaces form a first space 2e.

[0058] A second space 2f is provided in the warm water unit 2, i.e., in the first space 2e. The second space 2f is surrounded by a non-breathable member 2d and at least any one of the exterior bodies 2a, i.e., the top surface, the bottom surface, and the elevation surfaces composed of the front surface, the side surface and the rear surface. The water refrigerant heat exchanger 4 is placed in the second space 2f.

[0059] The non-breathable member 2d is a member which does not have a breathable function, e.g., a metal plate or the like having no opening.

[0060] According to this, refrigerant which leaks from the water refrigerant heat exchanger 4 can be retained in the second space 2f which is surrounded by the exterior bodies 2a and the non-breathable member 2d.

[0061] As shown in Figs. 3 and 4, portions of the exterior bodies 2a have openings 2c. According to this, refrigerant which leaks from the water refrigerant heat exchanger 4 is discharged to outside of the exterior bodies 2a of the warm water unit 2 from the second space 2f which is surrounded by the exterior bodies 2a and the non-breathable member 2d through the openings 2c. Hence, it is possible to prevent the combustible refrigerant from permeating the warm water unit 2.

[0062] Although the openings 2c are placed below the second space 2f in Fig. 4, the openings 2c may be placed above the second space 2f by installation environment of the warm water unit 2 or using a discharging fan.

[0063] The non-breathable member 2d is detachable from the exterior bodies 2a. According to this, if the non-breathable member 2d is detached, it is possible to touch the water refrigerant heat exchanger 4 from the inner side of the warm water unit 2 without detaching the exterior bodies 2a in Fig. 4. Hence, it is possible to easily do maintenance work such as exchange of the water refrigerant heat exchanger 4.

[0064] As shown in Figs. 4 and 5, the refrigerant pipe 8 and the heat medium pipe 20 which is the heat medium path 12a are connected to the water refrigerant heat exchanger 4 through a pipe mounting member 12c. The heat medium path 12a is connected to the water refrigerant heat exchanger 4 through a penetrating portion 12e provided in the non-breathable member 2d.

[0065] At this time, the pipe mounting member 12c includes a flange portion 12d, and the refrigerant pipe 8 and the heat medium path 12a are fixed to the non-breathable member 2d through the pipe mounting member 12c having the flange portion 12d as shown in Figs. 5.

[0066] According to this, a gap generated between the heat medium path 12a and the penetrating portion 12e of the non-breathable member 2d can be filled with the flange portion 12d. Therefore, combustible refrigerant which leaks from the water refrigerant heat exchanger 4 can be prevented from leaking out from this gap, and from permeating the warm water unit 2, i.e., the first space 2e located outside of the second space 2f.

[1-2. Action]

[0067] Action of the heat pump system in the embodiment will be described below.

[0068] The heat pump system in the embodiment can execute at least a heating operation for supplying heat medium to the heating terminal 19 provided in the heat medium circuit 12 to heat a room, a hot water storing operation for storing high temperature heat medium or warm water in the hot water tank 15, and a defrosting operation for defrosting frost attached to the evaporator 6a.

[0069] When a user instructs to start the operations by means of the remote controller 22, or when the control device 21 of the heat pump system determines that it is necessary to execute the operations due to time period or temperature around the heat pump system, these operations are started.

[0070] When the user instructs to start the heating operation by operation of the remote controller 22, or when the control device 21 determines that the heating operation is necessary due to temperature in a room or the like, the control device 21 starts the heating operation.

[0071] In the heating operation, the control device 21 drives the compressor 3 of the heat pump cycle and the circulation pump 9 provided in the heat medium circuit 12. When the decompressor 5 is an electromagnetic expansion valve, the control device 21 adjusts its valve-opening degree.

[0072] The control device 21 switches the three-way valve 16 to a downstream side of the heat medium circuit 12. According to this, refrigerant circulates through the heat pump cycle. Heat medium circulates through the heat medium circuit 12 and flows through the heating terminal 19.

[0073] If the compressor 3 is driven, refrigerant circulates through the heat pump cycle. Refrigerant is compressed by the compressor 3 and is brought into a high temperature and high pressure state. The high temperature and high pressure refrigerant flows into the water refrigerant heat exchanger 4 through the four-way valve 7, and releases heat to heat medium.

[0074] The refrigerant which flows out from the water refrigerant heat exchanger 4 is reduced in pressure by the decompressor 5. The refrigerant which flows out from the decompressor 5 exchanges heat with air which is sent by the blower fan 6b and evaporates in the evaporator 6a. Thereafter, the refrigerant which flows out from the evaporator 6a flows into the compressor 3 through the four-way valve 7, and the refrigerant is again compressed. In this manner, the refrigerant circulates through the heat pump cycle.

[0075] By driving the circulation pump 6, heat medium circulates through the heat medium circuit 12. The heat medium which circulates through the heat medium circuit 12 is heated by heat of refrigerant in the water refrigerant heat exchanger 4, and temperature of the heat medium becomes high. Here, the three-way valve 16 is set such that heat medium flows to a downstream side of the heat medium circuit 12.

[0076] Hence, heat medium which flows out from the water refrigerant heat exchanger 4 and flows through the heating portion 14 flows out to the heat medium circuit 12 located outside of the warm water unit 2 through the three-way valve 16 and the first heating connection 20a, and the heat medium flows into a heat-use terminal 19 (e.g., floor heating). After the heat medium releases heat in the heating terminal 19, the heat medium again flows into the heat medium path 12a from the first heating connection 20a. The heat medium circulates through the heat medium circuit 12 in this manner.

[0077] The control device 21 controls the heat pump cycle and the circulation pump 9 such that temperature of heat medium supplied to the heating terminal 19 becomes equal to predetermined temperature. For example, the control device 21 can control the number of rotations of the compressor 3 and the decompressor 5 such that temperature (discharging temperature) of heat medium which flows out from the water refrigerant heat exchanger 4 becomes equal to target temperature, and the control device 21 can control the number or rotations of the circulation pump 9 such that temperature (water-entering temperature) of heat medium which flows into the water refrigerant heat exchanger 4 becomes equal to predetermined temperature.

[0078] That is, the heat pump cycle controls discharging temperature such that temperature (discharging temperature) of refrigerant discharged from the compressor 3 becomes equal to predetermined temperature, and a circulation pump controls water-entering temperature to adjust temperature (water-entering temperature) of heat medium which flows into the water refrigerant heat exchanger 4. When heat medium cannot sufficiently be heated only by the heat pump cycle, the control device 21 heats the heat medium using the heating portion 14.

[0079] When a user instructs to start the hot water storing operation by operating the remote controller 22, or when the control device 21 determines that the hot water storing operation is necessary due to temperature of water in the hot water tank 15 or time period, the control device 21 starts the hot water storing operation.

[0080] In the hot water storing operation, the control device 21 drives the compressor 3 of the heat pump cycle and the circulation pump 9 provided in the heat medium circuit 12. When the decompressor 5 is an electromagnetic expansion valve, the control device 21 adjusts its valve-opening degree.

[0081] The control device 21 switches the three-way valve 16 to the bypass path 12b in the hot water storing operation. According to this, refrigerant circulates through the heat pump cycle and heat medium flows through the heat exchanger 15a. A user can adjust, by the remote controller 22, temperature of the heat medium supplied to the heat exchanger 15a.

[0082] The heat medium which flows into the bypass path 12b and flows through the heat exchanger 15a releases heat to water which is stored in the hot water tank 15, and heats the water. According to this, high temperature water is stored in the hot water tank 15.

[0083] In the hot water supply operation, the heated water flows out into the hot water-discharging pipe 30, the water flows out to outside of the warm water unit 2 through the second hot water supply connection 30b, and the water is supplied to the hot water supply terminal 33. That is, the hot water supply operation is carried out using high temperature water stored in the hot water tank 15.

[0084] In the hot water storing operation, the control device 21 controls the heat pump cycle and the circulation pump 9 such that temperature of heat medium supplied to the heat exchanger 15a becomes equal to predetermined temperature.

[0085] For example, the number of rotations of the compressor 3 and the decompressor 5 can be controlled such that temperature (hot water-discharging temperature) of the heat medium which flows out from the water refrigerant heat exchanger 4 becomes equal to target temperature, and the number of rotations of the circulation pump 9 can be controlled such that temperature (water-entering temperature) of the heat medium which flows into the water refrigerant heat exchanger 4 becomes equal to predetermined temperature.

[0086] When the heat medium cannot sufficiently be heated only by the heat pump cycle, the control device 21 heats the heat medium using the heating portion 14.

[0087] When outside air temperature becomes equal to or lower than predetermined temperature, or when temperature of refrigerant which flows through the evaporator 6a becomes equal to or lower than predetermined temperature, the control device 21 determines that frost is attached to the evaporator 6a, the control device 21 executes the defrosting operation to remove the frost.

[0088] In the defrosting operation, the control device 21 switches a circulation direction of refrigerant by the four-way valve 7. According to this, the refrigerant flows through the compressor 3, the four-way valve 7, the evaporator 6a, and the decompressor 5, the water refrigerant heat exchanger 4, the four-way valve 7 and the compressor 3 in this order. As a result, high temperature and high pressure refrigerant flows into the evaporator 6a, and the defrosting operation is carried out.

[0089] For example, when temperature of heat medium which flows into the water refrigerant heat exchanger 4 is lower than predetermined temperature, the control device 21 activates the heating portion 14 to heat the heat medium, and the heated heat medium is made to circulate through the heat medium circuit 12.

[0090] According to this, the heat medium in the heat medium circuit 12 can be prevented from being frozen. When the defrosting operation is carried out during execution of the heating operation or the hot water storing operation, it is possible to prevent heat medium to be supplied to the heating terminal 19 or the heat exchanger 15a from being lowered, and usability is enhanced.

[1-3. Effect and the like]

[0091] As in this embodiment, the warm water unit 2 includes: the water refrigerant heat exchanger 4 through which high pressure side combustible refrigerant of the heat pump cycle and heat medium flow together, and in which the combustible refrigerant and the heat medium exchange heat therebetween to produce warm water; the first space 2e formed of the plurality of exterior bodies 2a; and the second space 2f formed of the non-breathable member 2d and the exterior bodies 2a and provided in the first space 2e, wherein the water refrigerant heat exchanger 4 is placed in the second space 2f.

[0092] According to this, it is possible to provide the warm water unit 2 in which even if the combustible refrigerant leaks from the water refrigerant heat exchanger 4, the leaked combustible refrigerant can be stored in the second space 2f, and it is possible to prevent the combustible refrigerant from flowing into the first space 2e which is located outside of the second space 2f where an electrical part or the like is placed, and from permeating the first space 2e.

[0093] In the warm water unit 2, the exterior bodies 2a forming the second space 2f include openings 2c, and the second space 2f and outer sides of the exterior bodies 2a forming the second space 2f are in communication with each other.

[0094] According to this, combustible refrigerant which leaks into the second space 2f and accumulates therein can be discharged to outside of the warm water unit 2. Hence, it is possible to provide the warm water unit 2 capable of preventing combustible refrigerant from permeating the warm water unit 2, i.e., the first space 2e located outside of the second space 2f.

[0095] The warm water unit 2 is characterized in that the non-breathable member 2d can be attached to and detached from the exterior bodies 2a which form the second space 2f.

[0096] According to this, it is possible to touch the water refrigerant heat exchanger 4 by detaching the non-breathable member 2d from the exterior bodies 2a. Hence, it is possible to provide the warm water unit 2 capable of easily doing the maintenance work such as exchange of the water refrigerant heat exchanger 4.

[0097] The warm water unit 2 is characterized in that it includes the refrigerant pipe 8 connected to the water refrigerant heat exchanger 4, and the heat medium pipe 20 which is the heat medium path 12a, the non-breathable member 2d is provided with the refrigerant pipe 8 and the penetrating portion 12e through which the heat medium pipe 20 penetrates, and the refrigerant pipe 8 and the heat medium pipe 20 are fixed to the non-breathable member 2d by the pipe mounting member 12c having the flange portion 12d which closes a gap between the refrigerant pipe 8, the heat medium pipe 20 and the penetrating portion 12e.

[0098] According to this, it is possible to provide the warm water unit 2 capable of preventing combustible refrigerant which leaks into and accumulates in the second space 2f from penetrating through the penetrating portion 12e and from flowing into the warm water unit 2, i.e., into the first space 2e located outside of the second space 2f, and from permeating the warm water unit 2, i.e., the first space 2e.

[0099] The warm water unit 2 and the heat pump unit 1 where the compressor 3, the decompressor 5 and the evaporator 6a are placed are connected to each other through the refrigerant pipe 8, and the warm water unit 2 and the heat pump unit 1 constitute the heat pump system.

[0100] According to this, among the constituent parts of the heat pump cycle, a part placed in the warm water unit 2 is only the water refrigerant heat exchanger 4, and it is possible to provide a heat pump system capable of sufficiently preventing the ignition risk or the like of leaked refrigerant.

[INDUSTRIAL APPLICABILITY]

[0101] As described above, the present disclosure can provide a heat pump system in which even if combustible refrigerant leaks from a water refrigerant heat exchanger, it is possible to prevent the combustible refrigerant from permeating or accumulating in an entire interior of a warm water unit. Therefore, the present disclosure can be applied to a hot water supply system and a warm water heater.

[EXPLANATION OF SYMBOLS]

[0102] 

1

heat pump unit

2

warm water unit

2a

exterior body

2b

recess

2c

opening

2d

non-breathable member

2e

first space

2f

second space

3

compressor

4

water refrigerant heat exchanger

5

decompressor

6a

evaporator

7

four-way valve

8

refrigerant pipe

8a

first connection

8b

second connection

8c

first refrigerant pipe

8d

second refrigerant pipe

9

circulation pump

11

overpressure relief valve

12

heat medium circuit

12a

heat medium path

12b

bypass path

12c

pipe mounting member

12d

flange portion

12e

penetrating portion

14

heating portion

15

hot water tank

15a

heat exchanger

17

air vent valve

18

electric wiring

19

heating terminal

20

heat medium pipe

20a

first heating connection

20b

second heating connection

21

control device

22

remote controller

23

pressure indicator

30

hot water-discharging pipe

30a

first hot water supply connection

30b

second hot water supply connection

31

water supply pipe

32

pressure reducing valve

33

hot water supply terminal

34

mixing faucet

Claims

1. A warm water unit (2) comprising: a water refrigerant heat exchanger (4) through which high pressure side combustible refrigerant of a heat pump cycle and heat medium flow together, and in which the combustible refrigerant and the heat medium exchange heat therebetween to produce warm water; a first space (2e) formed of a plurality of exterior bodies (2a); and a second space (2f) formed of a non-breathable member (2d) and the exterior bodies (2a) and provided in the first space (2e), wherein
the water refrigerant heat exchanger (4) is placed in the second space (2f).

2. The warm water unit (2) according to claim 1, wherein the exterior bodies (2a) forming the second space (2f) include openings (2c), and the second space (2f) and outer sides of the exterior bodies (2a) forming the second space (2f) are in communication with each other.

3. The warm water unit (2) according to claim 1 or 2, wherein the non-breathable member (2d) can be attached to and detached from the exterior bodies (2a) which form the second space (2f).

4. The warm water unit (2) according to any one of claims 1 to 3, further comprising a refrigerant pipe (8) and a heat medium pipe (20) connected to the water refrigerant heat exchanger (4), wherein the non-breathable member (2d) is provided with a penetrating portion (12e) through which the refrigerant pipe (8) and the heat medium pipe (20) penetrate, and the refrigerant pipe (8) and the heat medium pipe (20) are fixed to the non-breathable member (2d) through a pipe mounting member (12c) having a flange portion (12d) which closes a gap between the refrigerant pipe (8), the heat medium pipe (20) and the penetrating portion (12e).

5. A heat pump system comprising the warm water unit (2) described in any one of claims 1 to 4, wherein the warm water unit (2) and a heat pump unit (1) where a compressor (3), a decompressor (5) and an evaporator (6a) are placed are connected to each other through a refrigerant pipe (8).

Drawing