Space heating device

Abstract

This space heating device comprises a heat medium circuit through which a first heat medium flows, a hot water circuit through which a second heat medium flows, and a control unit for performing control so as to close each of a first regulating valve and a second regulating valve when performing a defrosting operation in the heat medium circuit, wherein the hot water circuit comprises: a first radiator which is supplied with the second heat medium and which performs space heating of a first temperature regulation target; the first regulating valve which regulates the second heat medium flowing through the first radiator; a second radiator which is supplied with the second heat medium and which performs space heating of a second temperature regulation target; the second regulating valve which regulates the second heat medium flowing through the second radiator; and a bypass valve which is provided in a bypass pipe connecting either a first upstream branch pipe connected to the first radiator and a first downstream branch pipe, or a second upstream branch pipe connected to the first radiator and a second downstream branch pipe.

Description

heating equipment

[0001] The present disclosure relates to a heating device.

[0002] Patent Document 1 discloses a hot water heating system including a refrigerant circuit in which a compressor, a refrigerant-fluid heat exchanger, an expansion means, and an evaporator are connected in a ring, and a fluid circuit in which a circulation means, a refrigerant-fluid heat exchanger, a flow path switching valve, and a radiator are connected in a ring. Patent Document 1 also discloses that the system includes a bypass circuit that branches off from the flow path switching valve and is connected to the fluid circuit between the refrigerant-fluid heat exchanger and the radiator via a buffer tank. Patent Document 1 also discloses that when a defrosting operation of the evaporator is started, the flow path switching valve is switched to the bypass circuit side.

[0003] JP 2012-117711 A

[0004] When a heat pump air conditioner performs a defrosting operation, it is required to obtain the amount of heat required for defrosting.

[0005] The present disclosure provides a heating device in a heat pump type air conditioner that performs defrosting using the heat of a heat medium contained in piping.

[0006] a first heat medium circuit in which the first heat medium flows, the first heat medium being connected in a circular fashion to a compressor, a use-side heat exchanger that performs heat exchange between a first heat medium and a second heat medium, an expansion valve, and a heat source-side heat exchanger; a hot water circuit in which the second heat medium that has undergone heat exchange in the use-side heat exchanger flows, the hot water circuit comprising: an upstream heat exchange piping connected to the use-side heat exchanger and through which the second heat medium flowing out of the use-side heat exchanger flows; a downstream heat exchange piping connected to the use-side heat exchanger and through which the second heat medium flowing into the use-side heat exchanger flows; a first radiator to which the second heat medium is supplied and which heats a first temperature adjustment target; a first adjustment valve that adjusts the second heat medium flowing to the first radiator; a first upstream branch piping branched from the upstream heat exchange piping and connected to the first radiator; and a first downstream branch piping branched from the downstream heat exchange piping and connected to the first radiator. a second control valve that adjusts the second heat medium flowing through the second radiator; a second upstream branch pipe that branches off from the upstream heat exchange pipe and connects to the second radiator; a second downstream branch pipe that branches off from the downstream heat exchange pipe and connects to the second radiator; and a bypass valve that is provided in a bypass pipe that connects either between the first upstream branch pipe and the first downstream branch pipe or between the second upstream branch pipe and the second downstream branch pipe; and a control unit that controls the first control valve and the second control valve to be closed when a defrosting operation is performed in the heat medium circuit.

[0007] According to the heating device of the first aspect, defrosting can be performed using the heat of the heat medium contained in the piping in a heat pump type air conditioner.

[0008] A heating device of a second aspect may be the heating device of the first aspect, wherein the length of the piping from the use-side heat exchanger to the first radiator is longer than the length of the piping from the use-side heat exchanger to the second radiator, and the bypass valve may be provided between the first upstream branch piping and the first downstream branch piping.

[0009] A heating device of a third aspect may be the heating device of the first aspect, wherein the bypass valve is provided between the first upstream branch pipe and the first downstream branch pipe, and a length of a pipe through which the second heat medium flows from the use side heat exchanger to the bypass valve is longer than a first length, and the first length is a length such that an amount of heat stored in the second heat medium contained in the pipe through which the second heat medium flows from the use side heat exchanger to the bypass valve is equal to or greater than an amount of heat required for a defrosting operation in the heat medium circuit.

[0010] Fig. 1 is a diagram showing an outline of the configuration of a heating device according to a first embodiment. Fig. 2 is a flow chart for explaining the processing in the heating device according to the first embodiment. Fig. 3 is a flow chart for explaining a first defrosting operation in the heating device according to the first embodiment. Fig. 4 is a flow chart for explaining a second defrosting operation in the heating device according to the first embodiment. Fig. 5 is a flow chart for explaining a heat medium heating operation in the heating device according to the first embodiment. Fig. 6 is a diagram showing an outline of the configuration of a heating device according to a second embodiment. Fig. 7 is a diagram showing an outline of the configuration of a heating device according to a third embodiment.

[0011] Hereinafter, embodiments will be described with reference to the accompanying drawings. Note that, in the description of the specification and drawings relating to each embodiment, components having substantially the same or corresponding functional configurations may be designated by the same reference numerals, and redundant explanations may be omitted. Furthermore, to facilitate understanding, the scale of each part in the drawings may differ from the actual scale.

[0012] First Embodiment A heating device according to the first embodiment will be described. The heating device according to the first embodiment includes a heat medium circuit through which a first heat medium flows, a hot water circuit through which a second heat medium that has exchanged heat with the first heat medium flows, and a control unit. The heat medium circuit in the heating device according to the first embodiment includes a compressor, a user-side heat exchanger that exchanges heat between the first heat medium and the second heat medium, an expansion valve, and a heat-source-side heat exchanger that are connected in a ring shape, and through which the first heat medium flows.

[0013] The hot water circuit in the heating device according to the first embodiment is a circuit through which a second heat medium that has undergone heat exchange in a use-side heat exchanger flows. The hot water circuit in the heating device according to the first embodiment includes an upstream heat exchanger pipe connected to the use-side heat exchanger and through which the second heat medium flowing out of the use-side heat exchanger flows, and a downstream heat exchanger pipe connected to the use-side heat exchanger and through which the second heat medium flowing into the use-side heat exchanger flows. The hot water circuit in the heating device according to the first embodiment also includes a first radiator to which the second heat medium is supplied and which heats a first temperature control target, and a first control valve that adjusts the second heat medium flowing to the first radiator. The hot water circuit in the heating device according to the first embodiment also includes a first upstream branch pipe branching from the upstream heat exchanger pipe and connecting to the first radiator, and a first downstream branch pipe branching from the downstream heat exchanger pipe and connecting to the first radiator.

[0014] The hot water circuit in the heating device according to the first embodiment includes a second radiator to which a second heat medium is supplied and which heats a second temperature control target, and a second control valve that adjusts the second heat medium flowing through the second radiator. The hot water circuit in the heating device according to the first embodiment also includes a second upstream branch pipe that branches off from the upstream heat exchanger pipe and connects to the second radiator, and a second downstream branch pipe that branches off from the downstream heat exchanger pipe and connects to the second radiator.

[0015] Furthermore, the hot water circuit in the heating device according to the first embodiment includes a bypass valve provided in a bypass pipe connecting either the first upstream branch pipe and the first downstream branch pipe or the second upstream branch pipe and the second downstream branch pipe.

[0016] The control unit in the heating device according to the first embodiment controls the first control valve and the second control valve to be closed when a defrosting operation is performed in the heat medium circuit.

[0017] FIG. 1 is a diagram showing an outline of the configuration of a heating device 1, which is an example of a heating device according to the first embodiment. The heating device 1 is a heating device that heats temperature control targets RMa and RMb. The temperature control targets RMa and RMb are, for example, a living room, a kitchen, a toilet, a hallway, a conference room, a hall, etc. Note that the heating device 1, which is an example of a heating device according to the first embodiment, heats two temperature control targets, the temperature control target RMa and the temperature control target RMb, but the number of temperature control targets to be heated is not limited to two and may be multiple, for example, three or more.

[0018] The heating device 1 includes a heat medium circuit 10 through which a heat medium HM1 flows, a hot water circuit 20 through which a heat medium HM2 flows, and a control unit 30. The heat medium circuit 10, the hot water circuit 20, and the control unit 30 will be described in detail below.

[0019] [Heat Medium Circuit 10] The heat medium circuit 10 heats the heat medium HM2 circulating through the hot water circuit 20. The heat medium circuit 10 includes a compressor 11, a user-side heat exchanger 12, an expansion valve 13, a heat source-side heat exchanger 14, and a four-way valve 15. The heat medium circuit 10 includes the compressor 11, the user-side heat exchanger 12, the expansion valve 13, and the heat source-side heat exchanger 14 connected in a ring shape. The heat medium HM1 flows through the heat medium circuit 10. The user-side heat exchanger 12 exchanges heat between the heat medium HM1 and the heat medium HM2. The heat medium circuit 10 heats the heat medium HM2 by exchanging heat between the heat medium HM1 and the heat medium HM2 in the user-side heat exchanger 12.

[0020] The heat medium HM1 is a refrigerant such as a refrigerant alternative to chlorofluorocarbons (HCFCs) or hydrofluorocarbons (HFCs), etc. The heat medium HM2 is, for example, water.

[0021] The compressor 11, expansion valve 13, heat source-side heat exchanger 14, and four-way valve 15 may be collectively referred to as the outdoor unit 16. The outdoor unit 16 is installed outdoors. The outdoor unit 16 and the user-side heat exchanger 12 are connected by piping. Although the following description is made as the outdoor unit 16, the compressor 11, expansion valve 13, heat source-side heat exchanger 14, and four-way valve 15 may also be installed separately rather than together.

[0022] <Configuration of Heat Medium Circuit 10> Each element of the heat medium circuit 10 will be described in detail.

[0023] (Compressor 11) The compressor 11 compresses the heat medium HM1. The compressor 11 is, for example, a rotary compressor, a scroll compressor, a screw compressor, a turbo compressor, or the like. The rotation speed (operating frequency) of the motor in the compressor 11 can be varied by an inverter device. The capacity of the compressor 11 is controlled by controlling the rotation speed of the motor in the compressor 11.

[0024] (Use Side Heat Exchanger 12) The use side heat exchanger 12 exchanges heat between the heat medium HM1 and the heat medium HM2. The use side heat exchanger 12 is, for example, a plate type, spiral type, or double pipe type heat exchanger.

[0025] (Expansion Valve 13) The expansion valve 13 reduces the pressure of the heat medium HM1. The expansion valve 13 is, for example, an electric expansion valve.

[0026] (Heat Source Side Heat Exchanger 14) The heat source side heat exchanger 14 exchanges heat between the heat medium HM1 and outdoor air. The heat source side heat exchanger 14 is disposed outdoors, particularly outdoors. The heat source side heat exchanger 14 functions as a condenser or an evaporator. Outdoor air is supplied to the heat source side heat exchanger 14 by a fan 14f. Supplying outdoor air to the heat source side heat exchanger 14 by the fan 14f can promote heat exchange between the heat medium HM1 and the outdoor air.

[0027] (Four-way valve 15) The four-way valve 15 switches the flow path through which the heat medium HM1 flows.

[0028] <Operation of Heat Medium Circuit 10> Next, the operation of the heat medium circuit 10 will be described.

[0029] (Heating Operation) When the heating device 1 performs the heating operation, the heat medium circuit 10 supplies the high-temperature heat medium HM1 to the use-side heat exchanger 12 .

[0030] The heat medium circuit 10 switches the four-way valve 15 so that the heat medium HM1 flows from the compressor 11 to the use-side heat exchanger 12. The heat medium circuit 10 switches the four-way valve 15 so that the heat medium HM1 flows from the compressor 11, through the use-side heat exchanger 12, the expansion valve 13, and the heat-source-side heat exchanger 14 in this order, and then returns to the compressor 11.

[0031] The compressor 11 supplies the gaseous heat medium HM1 to the user-side heat exchanger 12. The user-side heat exchanger 12 exchanges heat between the heat medium HM1 and the heat medium HM2. After exchanging heat with the heat medium HM2 in the user-side heat exchanger 12, the heat medium HM1 becomes liquid. The expansion valve 13 reduces the pressure of the liquid heat medium HM1. The heat source-side heat exchanger 14 exchanges heat between the reduced pressure heat medium HM1 and outdoor air. After exchanging heat with the outdoor air in the heat source-side heat exchanger 14, the heat medium HM1 becomes gaseous. The gaseous heat medium HM1 returns to the compressor 11 and is compressed again.

[0032] (Defrosting Operation) When the heating device 1 performs a defrosting operation, the heat medium circuit 10 supplies the high-temperature heat medium HM1 to the heat source-side heat exchanger 14 .

[0033] The heat medium circuit 10 switches the four-way valve 15 so that the heat medium HM1 flows from the compressor 11 to the heat source-side heat exchanger 14. The heat medium circuit 10 switches the four-way valve 15 so that the heat medium HM1 flows from the compressor 11, through the heat source-side heat exchanger 14, the expansion valve 13, and the user-side heat exchanger 12, in that order, and then returns to the compressor 11.

[0034] The compressor 11 supplies the heat medium HM1 in a gaseous state to the heat source side heat exchanger 14. The heat source side heat exchanger 14 exchanges heat between the heat medium HM1 and outdoor air. After exchanging heat with the outdoor air in the heat source side heat exchanger 14, the heat medium HM1 becomes liquid. The expansion valve 13 reduces the pressure of the liquid heat medium HM1. The user side heat exchanger 12 exchanges heat between the reduced pressure heat medium HM1 and the heat medium HM2. After exchanging heat with the outdoor air in the user side heat exchanger 12, the heat medium HM1 becomes gaseous. The gaseous heat medium HM1 returns to the compressor 11 and is compressed again.

[0035] [Hot Water Circuit 20] The hot water circuit 20 heats the radiators 26a and 26b by the flow of the heat medium HM2 that has exchanged heat in the use-side heat exchanger 12. The hot water circuit 20 includes a radiator 26a that is supplied with the heat medium HM2 and heats the temperature adjustment target RMa. The hot water circuit 20 also includes a radiator 26b that is supplied with the heat medium HM2 and heats the temperature adjustment target RMb. The hot water circuit 20 also includes a control valve 27a that adjusts the amount of the heat medium HM2 flowing through the radiator 26a, and a control valve 27b that adjusts the amount of the heat medium HM2 flowing through the radiator 26b.

[0036] The hot water circuit 20 includes an upstream heat exchange piping 21 and a downstream heat exchange piping 22 for flowing the heat medium HM2 between the use-side heat exchanger 12 and each of the radiators 26a and 26b. The hot water circuit 20 also includes upstream branch piping 23a and 23b, and downstream branch piping 24a and 24b. The hot water circuit 20 also includes a bypass piping 25 connecting the upstream branch piping 23a and the downstream branch piping 24a. The hot water circuit 20 also includes a bypass valve 28 in the bypass piping 25. The hot water circuit 20 also includes a pump 29 for flowing the heat medium HM2.

[0037] Each component of the hot water circuit 20 will now be described in detail.

[0038] (Upstream heat exchange piping 21) The upstream heat exchange piping 21 is connected to the use-side heat exchanger 12. More specifically, the upstream heat exchange piping 21 is a piping from the use-side heat exchanger 12 to a branch point Pa1 where the piping branches into the radiator 26 a and the radiator 26 b. The upstream heat exchange piping 21 is a piping through which the heat medium HM2 flowing out from the use-side heat exchanger 12 flows.

[0039] The upstream heat exchange pipe 21 may be configured by connecting multiple pipes, for example. The upstream heat exchange pipe 21 may also include a component such as a pump along the way. Furthermore, the upstream heat exchange pipe 21 may also include a branch to a component other than the radiator 26 a and the radiator 26 b along the way. The same applies to the pipes described below in this disclosure.

[0040] (Downstream heat exchange piping 22) The downstream heat exchange piping 22 is connected to the use-side heat exchanger 12. More specifically, the downstream heat exchange piping 22 is a piping from the use-side heat exchanger 12 to a branch point Pb1 where the piping branches into the radiator 26 a and the radiator 26 b. The downstream heat exchange piping 22 is a piping through which the heat medium HM2 flowing into the use-side heat exchanger 12 flows.

[0041] (Upstream branch pipe 23a and upstream branch pipe 23b) The upstream branch pipe 23a is provided branching from the upstream heat exchange pipe 21 to the radiator 26a. The upstream branch pipe 23a is connected to the radiator 26a. More specifically, the upstream branch pipe 23a is a pipe from a branch point Pa1 to the radiator 26a.

[0042] The upstream branch pipe 23b is provided by branching off from the upstream heat exchange pipe 21 to the radiator 26b. The upstream branch pipe 23b is connected to the radiator 26b. More specifically, the upstream branch pipe 23b is a pipe extending from the branch point Pa1 to the radiator 26b.

[0043] (Downstream branch pipe 24a and downstream branch pipe 24b) The downstream branch pipe 24a is provided branching off from the downstream heat exchange pipe 22 to the radiator 26a. The downstream branch pipe 24a is connected to the radiator 26a. More specifically, the downstream branch pipe 24a is a pipe extending from a branch point Pb1 to the radiator 26a.

[0044] The downstream branch pipe 24b is provided by branching off from the downstream heat exchange pipe 22 to the radiator 26b. The downstream branch pipe 24b is connected to the radiator 26b. More specifically, the downstream branch pipe 24b is a pipe extending from a branch point Pb1 to the radiator 26b.

[0045] (Bypass piping 25) The bypass piping 25 connects the upstream branch piping 23 a and the downstream branch piping 24 a. More specifically, the bypass piping 25 connects a connection point Pa2 provided in the middle of the upstream branch piping 23 a and a connection point Pb2 provided in the middle of the downstream branch piping 24 a.

[0046] In the heating device 1, the bypass pipe 25 connects the upstream branch pipe 23a and the downstream branch pipe 24a, but the bypass pipe 25 may also connect the upstream branch pipe 23b and the downstream branch pipe 24b. In other words, the bypass pipe in the heating device according to the first embodiment may connect either the first upstream branch pipe and the first downstream branch pipe or the second upstream branch pipe and the second downstream branch pipe.

[0047] (Heat radiator 26a and heat radiator 26b) The heat radiator 26a and the heat radiator 26b heat the temperature control target, respectively. More specifically, the heat radiator 26a heats the temperature control target RMa. The heat radiator 26b heats the temperature control target RMb.

[0048] The heat medium HM2 is supplied to each of the radiators 26a and 26b. Each of the radiators 26a and 26b uses the supplied heat medium HM2 to heat a temperature control target, for example, a space in which the radiators 26a and 26b are installed. Each of the radiators 26a and 26b is, for example, a radiator, a fan convector, a floor heating panel, or the like. Each of the radiators 26a and 26b is provided far away from the user-side heat exchanger 12.

[0049] (Adjustment valve 27a and adjustment valve 27b) The adjustment valve 27a and adjustment valve 27b each adjust the flow rate of the heat medium HM2 supplied to the radiator. Specifically, the adjustment valve 27a is provided in the upstream branch pipe 23a connected to the radiator 26a. The adjustment valve 27a adjusts the flow rate of the heat medium HM2 supplied to the radiator 26a. The adjustment valve 27b is provided in the upstream branch pipe 23b connected to the radiator 26b. The adjustment valve 27b adjusts the flow rate of the heat medium HM2 supplied to the radiator 26b.

[0050] The adjustment valve 27a and the adjustment valve 27b are each controlled by the control unit 30. The control unit 30 adjusts the flow rate of the heat medium HM2 flowing through the radiator 26a and the radiator 26b, respectively, by controlling the adjustment valve 27a and the adjustment valve 27b, respectively.

[0051] The adjustment valve 27a is not limited to being provided in the upstream branch pipe 23a, but may also be provided in the downstream branch pipe 24a, or may be provided in both the upstream branch pipe 23a and the downstream branch pipe 24a. Similarly, the adjustment valve 27b is not limited to being provided in the upstream branch pipe 23b, but may also be provided in the downstream branch pipe 24b, or may be provided in both the upstream branch pipe 23b and the downstream branch pipe 24b.

[0052] (Bypass Valve 28) The bypass valve 28 is provided in the bypass pipe 25 that connects the upstream branch pipe 23a and the downstream branch pipe 24a.

[0053] The bypass valve 28 is preferably at least a first length away from the use-side heat exchanger 12. The first length is a distance at which the amount of heat stored in the heat medium HM2 contained in the piping from the use-side heat exchanger 12 to the bypass valve 28 is equal to or greater than the amount of heat required for the defrosting operation in the heat medium circuit 10.

[0054] For example, the amount of heat required for defrosting operation is Q (unit: joules), the specific heat of the heat medium HM2 is c (joules per kilogram per Kelvin), the temperature difference of the heat medium HM2 during defrosting operation is ΔT (unit: Kelvin), and the density of the heat medium HM2 is ρ (unit: kilograms per cubic meter). The inner diameter of the piping is D (unit: meters). If the length (first length) of the piping from the user side heat exchanger 12 to the bypass valve 28 at which the amount of heat stored in the heat medium HM2 is equal to or greater than the amount of heat required for defrosting operation in the heat medium circuit 10 is L (unit: meters), L can be calculated using the following equation 1.

[0055] L=Q / c / ΔT / ρ / (πD ２ / 4) ... (Formula 1)

[0056] In addition, when a bypass pipe 25 is provided to connect the upstream branch pipe 23b and the downstream branch pipe 24b, a bypass valve 28 is provided in the bypass pipe 25 to connect the upstream branch pipe 23b and the downstream branch pipe 24b.

[0057] (Pump 29) The pump 29 sends the heat medium HM2 to each of the radiators 26a and 26b. The pump 29 is, for example, an axial flow pump. The pump 29 is provided in the upstream heat exchange pipe 21.

[0058] The pump 29 is controlled by the control unit 30. The pump 29 has, for example, a flow rate and the like controlled by the control unit 30.

[0059] [Control Unit 30] The control unit 30 controls the heating device 1. Specifically, the control unit 30 controls the heat medium circuit 10 and the hot water circuit 20.

[0060] The control unit 30 is, for example, a control circuit including a processor such as a CPU (Central Processing Unit) and a memory. The functions of the control unit 30 are realized by the processor operating in accordance with a program readably stored in the memory. A specific example of the control unit 30 is a microcomputer. The control unit 30 may also be an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit).

[0061] The control unit 30 controls the control valves 27a and 27b to close when a defrosting operation is performed in the heat medium circuit 10. Closing the control valves 27a and 27b causes the pressure in the piping to exceed the operating pressure of the bypass valve 28, which opens the bypass valve 28. The bypass valve 28 may be an electric valve rather than a pressure valve. If the bypass valve 28 is an electric valve, the control unit 30 controls the bypass valve 28 to open when a defrosting operation is performed in the heat medium circuit 10.

[0062] The heating device 1 closes the control valves 27a and 27b and opens the bypass valve 28 to perform a first defrosting operation in the heat medium circuit 10. By performing the first defrosting operation by closing the control valves 27a and 27b and opening the bypass valve 28, the heating device 1 performs the defrosting operation in the heat medium circuit 10 using the heat quantity of the heat medium HM2 contained in the piping from the use side heat exchanger 12 to the bypass valve 28. Furthermore, by performing the first defrosting operation by closing the control valves 27a and 27b and opening the bypass valve 28 to perform the defrosting operation in the heat medium circuit 10, it is possible to prevent the heat medium HM2, the temperature of which has been reduced by the defrosting operation, from flowing through the radiators 26a and 26b.

[0063] The control unit 30 also controls to perform a second defrosting operation in which either the control valve 27a or the control valve 27b is opened, the pressure is reduced to or below the operating pressure of the bypass valve 28, and the bypass valve 28 is closed, thereby performing a defrosting operation in the heat medium circuit 10. For example, by performing the second defrosting operation in which the control valve 27a is opened, the pressure is reduced to or below the operating pressure of the bypass valve 28, and the bypass valve 28 is closed, the defrosting operation in the heat medium circuit 10 can be performed using the heat quantity of the heat medium HM1 contained in the radiator 26a.

[0064] In the above example, the control valve 27a is opened in the second defrosting operation, but at least one of the control valves 27a and 27b may be opened to perform the defrosting operation in the heat medium circuit 10 using the heat quantity of the heat medium HM2 contained in the radiator whose control valve is open. In other words, in the first defrosting operation in the heating device according to the first embodiment, the defrosting operation may be performed by opening either or both of the first control valve and the second control valve and closing the control valves other than the opened control valve and the bypass valve.

[0065] The control unit 30 may perform the second defrosting operation after performing the first defrosting operation.

[0066] Furthermore, when the first defrosting operation is performed and the defrosting operation is completed, the control unit 30 may heat the heat medium HM2 using the heat medium circuit 10 until the temperature of the heat medium HM2 becomes equal to or higher than the first temperature, and then return to the heating operation. Furthermore, when the second defrosting operation is performed and the first defrosting operation is performed and the defrosting operation is completed, the control unit 30 may control the operation to heat the heat medium HM2 using the heat medium circuit 10 until the temperature of the heat medium HM2 sent to the radiator becomes equal to or higher than the second temperature, and then return to the heating operation.

[0067] Specific processing in the heating device according to the first embodiment will be described using the heating device 1. Fig. 2 is a flow chart for explaining processing in the heating device 1, which is an example of the heating device according to the first embodiment.

[0068] It is assumed that the heating device 1 is performing heating operation.

[0069] (Step S10) When the heating device 1 starts processing, the control unit 30 determines whether a defrosting operation is required in the outdoor unit 16. Specifically, the control unit 30 determines whether a defrosting operation is required to remove frost that has adhered to the heat source side heat exchanger 14. The control unit 30, for example, acquires the temperature in the heat source side heat exchanger 14 and determines whether frost has formed on the heat source side heat exchanger 14. The control unit 30 acquires the temperature in the heat source side heat exchanger 14, and if it determines that a predetermined amount of frost has formed on the heat source side heat exchanger 14, the control unit 30 determines that a defrosting operation is required.

[0070] If the control unit 30 determines that a defrosting operation is necessary (YES in step S10), the control unit 30 proceeds to step S20. If the control unit 30 determines that a defrosting operation is not necessary (NO in step S10), the control unit 30 returns to step S10 and repeats the process.

[0071] (Step S20) When the control unit 30 determines that a defrosting operation is necessary (YES in step S10), the control unit 30 performs control so as to perform a first defrosting operation.

[0072] In the first defrosting operation, the heat medium HM2 is caused to flow through the bypass piping 25, and the heat quantity of the heat medium HM2 contained in the piping from the user side heat exchanger 12 to the bypass piping 25 is used to perform a defrosting operation for the outdoor unit 16, specifically, a defrosting operation for defrosting the heat source side heat exchanger 14.

[0073] The first defrosting operation will be described in detail below. Fig. 3 is a flow chart for explaining the first defrosting operation in the heating apparatus 1, which is an example of the heating apparatus according to the first embodiment.

[0074] (Step S21) The control unit 30 first controls the adjustment valve 27a, which adjusts the flow rate of the heat medium HM2 flowing through the radiator 26a, and the adjustment valve 27b, which adjusts the flow rate of the heat medium HM2 flowing through the radiator 26b, to be closed. By closing the adjustment valve 27a and the adjustment valve 27b, the heat medium HM2 cooled by the defrosting operation in the outdoor unit 16 (heat source-side heat exchanger 14) can be prevented from flowing into the radiators 26a and 26b.

[0075] Closing the control valves 27a and 27b causes the pressure in the piping to exceed the operating pressure of the bypass valve 28, thereby opening the bypass valve 28. Opening the bypass valve 28 causes the heat medium HM1 flowing through the outdoor unit 16 (heat source-side heat exchanger 14) to be heated by the heat of the heat medium HM2 contained in the piping between the use-side heat exchanger 12 and the bypass valve 28.

[0076] (Step S22) Next, the control unit 30 performs a defrosting operation in the heat medium circuit 10 (the outdoor unit 16 and the heat source-side heat exchanger 14). The control unit 30 controls the four-way valve 15 so that the heat medium HM1 flows from the compressor 11 to the heat source-side heat exchanger 14. The control unit 30 then operates the compressor 11 to heat the heat source-side heat exchanger 14. By heating the heat source-side heat exchanger 14, frost adhering to the heat source-side heat exchanger 14 is removed.

[0077] (Step S23) Next, the control unit 30 determines whether defrosting is complete in the heat-source-side heat exchanger 14. For example, the control unit 30 acquires the temperature in the heat-source-side heat exchanger 14 and determines whether frost remains in the heat-source-side heat exchanger 14. If the control unit 30 acquires the temperature in the heat-source-side heat exchanger 14 and determines that frost remains in the heat-source-side heat exchanger 14, the control unit 30 determines that defrosting is not complete. If the control unit 30 acquires the temperature in the heat-source-side heat exchanger 14 and determines that no frost remains in the heat-source-side heat exchanger 14, the control unit 30 determines that defrosting is complete.

[0078] If the control unit 30 determines that the defrosting is completed (YES in step S23), the control unit 30 ends the first defrosting operation. If the control unit 30 determines that the defrosting is not completed (NO in step S23), the control unit 30 proceeds to step S24.

[0079] (Step S24) Next, the control unit 30 acquires the temperature of the heat medium HM2 that has flowed through the use-side heat exchanger 12, and if the measured temperature is equal to or higher than the threshold value (YES in step S24), the control unit 30 ends the first defrosting operation. If the temperature of the heat medium HM2 that has flowed through the use-side heat exchanger 12 is lower than the threshold value (NO in step S24), the control unit 30 returns to step S23 and repeats the process.

[0080] (Step S30) When the first defrosting operation is completed, the control unit 30 determines whether or not the first defrosting operation has completed defrosting in the heat source side heat exchanger 14. Specifically, the control unit 30 determines whether or not it has been determined in step S23 that defrosting has been completed.

[0081] If defrosting is completed in the first defrosting operation (YES in step S30), the control unit 30 proceeds to step S50. If defrosting is not completed in the first defrosting operation (NO in step S30), the control unit 30 proceeds to step S40.

[0082] (Step S40) If defrosting is not completed in the first defrosting operation (NO in step S30), the control unit 30 performs control so as to perform the second defrosting operation.

[0083] In the second defrosting operation, the heat quantity of the heat medium HM2 contained in at least one of the radiator 26a and the radiator 26b is used to perform the defrosting operation of the outdoor unit 16 (heat source side heat exchanger 14).

[0084] The second defrosting operation will be described in detail. Fig. 4 is a flow chart for explaining the second defrosting operation in the heating device 1, which is an example of the heating device according to the first embodiment. Note that, here, a case where the heat quantity of the heat medium HM2 contained in the radiator 26a is used will be described.

[0085] (Step S41) The control unit 30 controls the adjustment valve 27a to open. When the adjustment valve 27a opens, the pressure inside the piping becomes equal to or lower than the operating pressure of the bypass valve 28, and the bypass valve 28 closes. The bypass valve 28 may be an electric type instead of a pressure type. If the bypass valve 28 is an electric type, the control unit 30 controls the bypass valve 28 to close. When the bypass valve 28 closes, the heat medium HM2 does not flow through the bypass piping 25.

[0086] The heat source side heat exchanger 14 in the outdoor unit 16 is heated by the heat quantity of the heat medium HM2 contained in the radiator 26a.

[0087] (Step S42) Next, the control unit 30 determines whether defrosting is completed in the heat source side heat exchanger 14. For specific processing, refer to the description of step S23, and description thereof will be omitted here.

[0088] If the control unit 30 determines that the defrosting is complete (YES in step S42), the control unit 30 ends the second defrosting operation. If the control unit 30 determines that the defrosting is not complete (NO in step S42), the control unit 30 returns to step S42 and repeats the process.

[0089] (Step S50) The control unit 30 performs a heat medium heating process to heat the heat medium HM2. When the first defrosting operation is performed, the temperature of the heat medium HM2 decreases. When the second defrosting operation is performed in addition to the first defrosting operation, the temperature of the heat medium HM2 decreases further. When the temperature of the heat medium HM2 decreases and the heat medium HM2 with a decreased temperature flows through the radiator 26a and the radiator 26a, the temperatures of the temperature control targets RMa and RMb may temporarily decrease. When the temperatures of the temperature control targets RMa and RMb decrease, people in the temperature control targets RMa and RMb may feel uncomfortable.

[0090] Therefore, the heating device 1 heats the heat medium HM2 whose temperature has decreased due to the defrosting operation.

[0091] The heat medium treatment will be described in detail below. Fig. 5 is a flow chart for explaining the heat medium heating treatment in the heating device 1, which is an example of the heating device according to the first embodiment.

[0092] (Step S51) The control unit 30 controls the adjustment valves 27 a and 27 b to close. Closing the adjustment valves 27 a and 27 b prevents the heat medium HM2 cooled by the defrosting operation in the outdoor unit 16 (heat source-side heat exchanger 14) from flowing to the radiators 26 a and 26 b.

[0093] When the control valves 27 a and 27 b are closed, the pressure in the piping becomes equal to or greater than the operating pressure of the bypass valve 28, and the bypass valve 28 opens. When the bypass valve 28 opens, the heat medium HM2 contained in the piping between the use-side heat exchanger 12 and the bypass valve 28 is heated by the outdoor unit 16 (heat-source-side heat exchanger 14).

[0094] (Step S52) Next, the control unit 30 heats the heat medium HM2 using the heat medium circuit 10 (outdoor unit 16, heat source side heat exchanger 14). The control unit 30 controls the four-way valve 15 so that the heat medium HM1 flows from the compressor 11 to the use side heat exchanger 12. Then, the control unit 30 operates the compressor 11 to heat the use side heat exchanger 12. Heating the use side heat exchanger 12 heats the heat medium HM2.

[0095] (Step S53) Next, the control unit 30 determines whether the temperature of the heat medium HM2 is equal to or higher than a predetermined threshold. If the temperature of the heat medium HM2 is equal to or higher than the predetermined threshold (YES in step S53), the control unit 30 ends the heat medium heating process. If the temperature of the heat medium HM2 is lower than the predetermined threshold (NO in step S53), the control unit 30 returns to step S53 and repeats the process.

[0096] Note that the control unit 30 may change the threshold value between when only the first defrosting operation is performed and when both the first defrosting operation and the second defrosting operation are performed. In other words, when only the first defrosting operation is performed, the control unit 30 may heat the heat medium HM2 to a first temperature or higher, and when both the first defrosting operation and the second defrosting operation are performed, the control unit 30 may heat the heat medium HM2 to a second temperature or higher that is different from the first temperature. Note that it is preferable that the second temperature is higher than the first temperature.

[0097] (Step S60) The control unit 30 starts the heating process.

[0098] According to the heating device of the first embodiment, defrosting can be performed with a simple configuration in a heat pump type air conditioner by using the heat quantity of the heat medium contained in the heat exchange piping.

[0099] Although the heating device 1 includes the bypass valve 28, in the heating device according to this embodiment, if the radiator is located far enough away, for example, if the radiator is located far enough away from the heat exchanger than the first distance, the bypass valve may not be necessary. This is because, if the radiator is located far enough away from the heat exchanger than the first distance, the heat quantity of the second heat medium in the piping is sufficient for defrosting.

[0100] Second Embodiment A heating device according to a second embodiment will be described. Using the heating device according to the second embodiment, an aspect in which a radiator is further provided in addition to the first and second radiators in the heating device according to the first embodiment will be described.

[0101] 6 is a diagram showing an outline of the configuration of a heating device 2, which is an example of a heating device according to the second embodiment. The heating device 2 is a heating device that heats temperature control targets RM1a, RM1b, and RM1c. The temperature control targets RM1a, RM1b, and RM1c are, for example, a living room, a kitchen, a toilet, a hallway, a conference room, a hall, etc.

[0102] The heating device 2 includes a heat medium circuit 10 through which the heat medium HM1 flows, a hot water circuit 120 through which the heat medium HM2 flows, and a control unit 130. For the heat medium circuit 10, refer to the description of the heat medium circuit 10 in the heating device 1, which is an example of the heating device according to the first embodiment, and a detailed description thereof will be omitted here.

[0103] [Hot Water Circuit 120] The hot water circuit 120 heats the radiators 126a, 126b, and 126c by the flow of the heat medium HM2 that has exchanged heat in the use-side heat exchanger 12. The hot water circuit 120 includes the radiator 126a that is supplied with the heat medium HM2 and heats the temperature adjustment target RM1a. The hot water circuit 120 also includes the radiator 126b that is supplied with the heat medium HM2 and heats the temperature adjustment target RM1b. The hot water circuit 120 also includes the radiator 126c that is supplied with the heat medium HM2 and heats the temperature adjustment target RM1c. The hot water circuit 120 also includes a control valve 127a that adjusts the amount of heat medium HM2 flowing to the radiator 126a, a control valve 127b that adjusts the amount of heat medium HM2 flowing to the radiator 126b, and a control valve 127c that adjusts the amount of heat medium HM2 flowing to the radiator 126c.

[0104] The hot water circuit 120 includes an upstream heat exchange pipe 121 and a downstream heat exchange pipe 122 for flowing the heat medium HM2 between the use-side heat exchanger 12 and each of the radiators 126a, 126b, and 126c. The hot water circuit 120 also includes upstream branch pipes 123a, 123b, 123c, and 123ab, as well as downstream branch pipes 124a, 124b, 124c, and 124ab. The hot water circuit 120 also includes a bypass pipe 125 connecting the upstream branch pipe 123ab and the downstream branch pipe 124ab. The hot water circuit 120 also includes a bypass valve 128 in the bypass pipe 125. The hot water circuit 120 also includes a pump 29 for flowing the heat medium HM2. Furthermore, the hot water circuit 120 includes a hot water tank 40 .

[0105] A detailed description will be given of each component of the hot water circuit 120. Note that for the components of the hot water circuit 120 that are common to both the hot water circuit 20 and the hot water circuit 20, the description of the hot water circuit 20 should be referred to, and detailed description thereof will be omitted here.

[0106] (Upstream heat exchange piping 121) The upstream heat exchange piping 121 is connected to the use-side heat exchanger 12. More specifically, the upstream heat exchange piping 121 is a piping from the use-side heat exchanger 12 to a branch point Pa11 where the piping branches to the radiator 126c. The heat medium HM2 flowing out from the use-side heat exchanger 12 flows through the upstream heat exchange piping 121.

[0107] (Downstream heat exchange piping 122) The downstream heat exchange piping 122 is connected to the use-side heat exchanger 12. More specifically, the downstream heat exchange piping 122 is a piping from the use-side heat exchanger 12 to a branch point Pb11 where the piping branches to the radiator 126c. The heat medium HM2 flowing into the use-side heat exchanger 12 flows through the downstream heat exchange piping 122.

[0108] (Upstream branch pipe 123a, upstream branch pipe 123b, upstream branch pipe 123c) The upstream branch pipe 123a is provided by branching from the upstream heat exchange pipe 121 to the radiator 126a via the upstream branch pipe 123ab. In this disclosure, the phrase "provided by branching from pipe A to element B" does not only refer to a case where "pipe A" is directly branched to "element B" but also includes a case where "pipe A" is indirectly branched to "element B", for example, via a branch pipe therebetween. The upstream branch pipe 123a is connected to the radiator 126a. More specifically, the upstream branch pipe 123a is a pipe from branch point Pa13 to the radiator 126a.

[0109] The upstream branch pipe 123b is provided by branching from the upstream heat exchange pipe 121 to the radiator 126b via the upstream branch pipe 123ab. The upstream branch pipe 123b is connected to the radiator 126b. More specifically, the upstream branch pipe 123b is a pipe from the branch point Pa13 to the radiator 126b.

[0110] The upstream branch pipe 123c is provided by branching off from the upstream heat exchange pipe 121 to the radiator 126c. The upstream branch pipe 123c is connected to the radiator 126c. More specifically, the upstream branch pipe 123c is a pipe extending from the branch point Pa11 to the radiator 126c.

[0111] (Upstream branch pipe 123ab) The upstream branch pipe 123ab is provided by branching off from the upstream heat exchange pipe 121. The upstream branch pipe 123ab is ultimately connected to each of the radiators 126a and 126b. More specifically, the upstream branch pipe 123ab is a pipe extending from the branch point Pa11 to the branch point Pa13.

[0112] (Downstream branch pipe 124a, downstream branch pipe 124b, and downstream branch pipe 124c) The downstream branch pipe 124a is provided by branching from the downstream heat exchange pipe 122 to the radiator 126a via a downstream branch pipe 124ab. The downstream branch pipe 124a is connected to the radiator 126a. More specifically, the downstream branch pipe 124a is a pipe from the branch point Pb13 to the radiator 126a.

[0113] The downstream branch pipe 124b is provided by branching from the downstream heat exchange pipe 122 to the radiator 126b via the downstream branch pipe 124ab. The downstream branch pipe 124b is connected to the radiator 126b. More specifically, the downstream branch pipe 124b is a pipe from the branch point Pb13 to the radiator 126b.

[0114] The downstream branch pipe 124c is provided by branching off from the downstream heat exchange pipe 122 to the radiator 126c. The downstream branch pipe 124c is connected to the radiator 126c. More specifically, the downstream branch pipe 124c is a pipe extending from the branch point Pb11 to the radiator 126c.

[0115] (Downstream branch pipe 124ab) The downstream branch pipe 124ab is provided by branching off from the downstream heat exchange pipe 122. The downstream branch pipe 124ab is ultimately connected to each of the radiators 126a and 126b. More specifically, the downstream branch pipe 124ab is a pipe extending from a branch point Pb11 to a branch point Pb13.

[0116] (Bypass piping 125) The bypass piping 125 connects the upstream branch piping 123ab and the downstream branch piping 124ab. More specifically, the bypass piping 125 connects a connection point Pa12 provided at the middle of the upstream branch piping 123ab and a connection point Pb12 provided at the middle of the downstream branch piping 124ab.

[0117] The bypass pipe 125 may be provided to connect the upstream branch pipe 123a and the downstream branch pipe 124a. The bypass pipe 125 may be provided to connect the upstream branch pipe 123b and the downstream branch pipe 124b. The bypass pipe 125 may be provided to connect the upstream branch pipe 123c and the downstream branch pipe 124c.

[0118] In other words, the heating device according to this embodiment may be a heating device including three or more radiators, and may be provided with bypass pipes in the upstream and downstream branch pipes after any one of the radiators branches off from the use-side heat exchanger. The heating device according to this embodiment may be provided with bypass valves in the bypass pipes. Furthermore, the control unit of the heating device according to this embodiment may control the control valves of the radiators to close when performing a defrosting operation in the heat medium circuit.

[0119] (Heat radiator 126a, radiator 126b, and radiator 126c) The radiator 126a, radiator 126b, and radiator 126c heat the temperature control target, respectively. More specifically, the radiator 126a heats the temperature control target RM1a. The radiator 126b heats the temperature control target RM1b. The radiator 126c heats the temperature control target RM1c.

[0120] The heat medium HM2 is supplied to each of the radiators 126a, 126b, and 126c. Each of the radiators 126a, 126b, and 126c uses the supplied heat medium HM2 to heat a temperature control target, for example, a space in which the radiators are installed. Each of the radiators 126a, 126b, and 126c is, for example, a radiator, a fan convector, or a floor heating panel. Each of the radiators 126a, 126b, and 126c is provided far away from the use-side heat exchanger 12.

[0121] (Adjustment valve 127a, adjustment valve 127b, and adjustment valve 127c) The adjustment valve 127a, adjustment valve 127b, and adjustment valve 127c each adjust the flow rate of the heat medium HM2 supplied to the radiator. Specifically, the adjustment valve 127a is provided in the upstream branch pipe 123a connected to the radiator 126a. The adjustment valve 127a adjusts the flow rate of the heat medium HM2 supplied to the radiator 126a. The adjustment valve 127b is provided in the upstream branch pipe 123b connected to the radiator 126b. The adjustment valve 127b adjusts the flow rate of the heat medium HM2 supplied to the radiator 126b. The adjustment valve 127c is provided in the upstream branch pipe 123c connected to the radiator 126c. The adjustment valve 127c adjusts the flow rate of the heat medium HM2 supplied to the radiator 126c.

[0122] The control valves 127a, 127b, and 127c are each controlled by the control unit 130. The control unit 130 adjusts the flow rate of the heat medium HM2 flowing through the radiator 126a, 126b, and 126c, respectively, by controlling the control valves 127a, 127b, and 127c, respectively.

[0123] The adjustment valve 127a is not limited to being provided in the upstream branch pipe 123a, but may be provided in the downstream branch pipe 124a, or may be provided in both the upstream branch pipe 123a and the downstream branch pipe 124a. The same applies to the adjustment valve 127b and the adjustment valve 127c.

[0124] (Bypass Valve 128) The bypass valve 128 is provided in the bypass pipe 125 that connects the upstream branch pipe 123ab and the downstream branch pipe 124ab.

[0125] The bypass valve 128 is preferably at least a first length away from the use-side heat exchanger 12. The first length is a distance at which the amount of heat stored in the heat medium HM2 contained in the piping from the use-side heat exchanger 12 to the bypass valve 128 is equal to or greater than the amount of heat required for the defrosting operation in the heat medium circuit 10.

[0126] (Hot water supply tank 40) The hot water supply tank 40 generates hot water. Water is stored in the hot water supply tank 40, and the heat medium HM2 is supplied to the hot water supply tank 40 to heat the stored water. The heat medium HM2 is supplied to the hot water supply tank 40 from the use-side heat exchanger 12 via the pump 29 and the three-way valve 41. The heat medium HM2 that has heated the water in the hot water supply tank 40 returns to the use-side heat exchanger 12.

[0127] The hot water supply tank 40 branches off from the upstream heat exchange piping 121 and is connected to the use-side heat exchanger 12. The three-way valve 41 is provided on the upstream heat exchange piping 121. The hot water supply tank 40 is also connected to a connection point Pb10 on the downstream heat exchange piping 122.

[0128] The three-way valve 41 is controlled by the control unit 130. The opening degree of the three-way valve 41 is controlled by the control unit 130, whereby the temperature of the water stored in the hot water supply tank 40 is controlled.

[0129] [Control unit 130] The control unit 130 controls the heating device 2. Specifically, the control unit 130 controls the heat medium circuit 10 and the hot water circuit 120. Note that since the control unit 130 has the same configuration and functions as the control unit 30, the description of the control unit 30 should be referred to and detailed description of the control unit 130 will be omitted here.

[0130] The control unit 130 controls the control valves 127a, 127b, and 127c to close when a defrosting operation is performed in the heat medium circuit 10. Closing the control valves 127a, 127b, and 127c causes the pressure in the piping to exceed the operating pressure of the bypass valve 28, and the bypass valve 28 opens. The bypass valve 28 may be an electric valve rather than a pressure valve. If the bypass valve 28 is an electric valve, the control unit 130 controls the bypass valve 28 to open when a defrosting operation is performed in the heat medium circuit 10.

[0131] The heating device 2 closes the control valves 127a, 127b, and 127c and opens the bypass valve 128 to perform a first defrosting operation in the heat medium circuit 10. The control unit 130 also controls at least one of the control valves 127a, 127b, and 127c to be opened. By opening at least one of the control valves 127a, 127b, and 127c, the pressure in the piping becomes equal to or lower than the operating pressure of the bypass valve 128, and by closing the bypass valve 128, a second defrosting operation is performed in the heat medium circuit 10.

[0132] According to the heating device of the second embodiment, as with the heating device of the first embodiment, defrosting can be performed with a simple configuration in a heat pump type air conditioner by using the heat quantity of the heat medium contained in the heat exchange piping.

[0133] Although the heating device 2 in the above example includes three radiators, the heating device according to this embodiment may include multiple radiators. The heating device according to this embodiment may include multiple radiators, and a bypass pipe may be provided in a branch pipe connected to any one of the multiple radiators, and the bypass pipe may be provided with a bypass valve. The control unit in the heating device according to this embodiment may control the control valves of the multiple radiators to close when performing a defrosting operation in the heat medium circuit.

[0134] Third Embodiment A heating device according to a third embodiment will be described. The heating device according to the third embodiment is the heating device according to the first embodiment, except that a branch pipe having a long pipe length from the utilization-side heat exchanger to the radiator is provided with a bypass pipe and a bypass valve in the bypass pipe.

[0135] 7 is a diagram showing an outline of the configuration of a heating device 3, which is an example of a heating device according to the third embodiment. The heating device 3 is a heating device that heats temperature control targets RM2a and RM2b. The temperature control targets RM2a and RM2b are, for example, a living room, a kitchen, a toilet, a hallway, a conference room, a hall, etc.

[0136] The heating device 3 includes a heat medium circuit 10 through which the heat medium HM1 flows, a hot water circuit 220 through which the heat medium HM2 flows, and a control unit 230. For the heat medium circuit 10, refer to the description of the heat medium circuit 10 in the heating device 1, which is an example of the heating device according to the first embodiment, and a detailed description thereof will be omitted here.

[0137] [Hot Water Circuit 220] The hot water circuit 220 heats a radiator 226a and a radiator 226b by the flow of the heat medium HM2 that has exchanged heat in the use-side heat exchanger 12. The hot water circuit 220 includes a radiator 226a that is supplied with the heat medium HM2 and heats a temperature adjustment target RM2a. The hot water circuit 220 also includes a radiator 226b that is supplied with the heat medium HM2 and heats a temperature adjustment target RM2b. The hot water circuit 220 also includes a control valve 227a that adjusts the amount of the heat medium HM2 flowing to the radiator 226a, and a control valve 227b that adjusts the amount of the heat medium HM2 flowing to the radiator 226b.

[0138] A detailed description will be given of each component of the hot water circuit 220. Note that for components of the hot water circuit 220 that are common to both the hot water circuit 20 and the hot water circuit 120, the descriptions of the hot water circuit 20 and the hot water circuit 120 should be referred to, and detailed description thereof will be omitted here.

[0139] (Upstream heat exchange piping 221) The upstream heat exchange piping 221 is connected to the use-side heat exchanger 12. More specifically, the upstream heat exchange piping 221 is a piping from the use-side heat exchanger 12 to a branch point Pa21 where the piping branches into the radiator 226 a and the radiator 226 b. The heat medium HM2 flowing out from the use-side heat exchanger 12 flows through the upstream heat exchange piping 221.

[0140] The upstream heat exchange pipe 221 is provided with a three-way valve 41 in the middle thereof to supply the heat medium HM2 to the hot water supply tank 40 .

[0141] (Downstream heat exchange piping 222) The downstream heat exchange piping 222 is connected to the use-side heat exchanger 12. More specifically, the downstream heat exchange piping 222 is a piping from the use-side heat exchanger 12 to a branch point Pb21 where the piping branches into the radiator 226 a and the radiator 226 b. The heat medium HM2 flowing into the use-side heat exchanger 12 flows through the downstream heat exchange piping 222.

[0142] The downstream heat exchange pipe 222 is connected to the hot water supply tank 40 at a connection point Pb20.

[0143] (Upstream branch pipe 223a and upstream branch pipe 223b) The upstream branch pipe 223a is provided branching from the upstream heat exchange pipe 221 to the radiator 226a. The upstream branch pipe 223a is connected to the radiator 226a. More specifically, the upstream branch pipe 223a is a pipe from the branch point Pa21 to the radiator 226a.

[0144] The upstream branch pipe 223b is provided by branching off from the upstream heat exchange pipe 221 to the radiator 226b. The upstream branch pipe 223b is connected to the radiator 226b. More specifically, the upstream branch pipe 223b is a pipe extending from the branch point Pa21 to the radiator 226b.

[0145] The radiator 226a is installed farther from the use-side heat exchanger 12 than the radiator 226b. Therefore, the upstream branch pipe 223a is longer than the upstream branch pipe 223b.

[0146] (Downstream branch pipe 224a and downstream branch pipe 224b) The downstream branch pipe 224a is provided branching off from the downstream heat exchange pipe 222 to the radiator 226a. The downstream branch pipe 224a is connected to the radiator 226a. More specifically, the downstream branch pipe 224a is a pipe extending from the branch point Pb21 to the radiator 226a.

[0147] The downstream branch pipe 224b is provided by branching off from the downstream heat exchange pipe 222 to the radiator 226b. The downstream branch pipe 224b is connected to the radiator 226b. More specifically, the downstream branch pipe 224b is a pipe extending from the branch point Pb21 to the radiator 226b.

[0148] The radiator 226a is installed farther from the use-side heat exchanger 12 than the radiator 226b. Therefore, the downstream branch pipe 224a is longer than the downstream branch pipe 224b.

[0149] (Bypass piping 225) The bypass piping 225 connects the upstream branch piping 223 a and the downstream branch piping 224 a. More specifically, the bypass piping 225 connects a connection point Pa22 provided at the middle of the upstream branch piping 223 a and a connection point Pb22 provided at the middle of the downstream branch piping 224 a.

[0150] The radiator 226a is installed farther from the use-side heat exchanger 12 than the radiator 226b. The bypass pipe 225 connects the upstream branch pipe 223a and the downstream branch pipe 224a, which are longer than the upstream branch pipe 223b and the downstream branch pipe 224b.

[0151] (Heat radiator 226a and heat radiator 226b) The heat radiator 226a and the heat radiator 226b heat the temperature control target RM2a, respectively. More specifically, the heat radiator 226a heats the temperature control target RM2a. The heat radiator 226b heats the temperature control target RM2b.

[0152] The heat medium HM2 is supplied to each of the radiators 226a and 226b. Each of the radiators 226a and 226b uses the supplied heat medium HM2 to heat a temperature control target, for example, a space in which the radiators 226a and 226b are installed. Each of the radiators 226a and 226b is, for example, a radiator, a fan convector, or a floor heating panel. Each of the radiators 226a and 226b is provided far away from the use-side heat exchanger 12.

[0153] (Adjustment valve 227a and adjustment valve 227b) The adjustment valve 227a and adjustment valve 227b each adjust the flow rate of the heat medium HM2 supplied to the radiator. Specifically, the adjustment valve 227a is provided in the upstream branch pipe 223a connected to the radiator 226a. The adjustment valve 227a adjusts the flow rate of the heat medium HM2 supplied to the radiator 226a. The adjustment valve 227b is provided in the upstream branch pipe 223b connected to the radiator 226b. The adjustment valve 227b adjusts the flow rate of the heat medium HM2 supplied to the radiator 226b.

[0154] The adjustment valves 227a and 227b are each controlled by a control unit 230. The control unit 230 adjusts the flow rate of the heat medium HM2 flowing through the radiator 226a and the radiator 226b, respectively, by controlling the adjustment valves 227a and 227b, respectively.

[0155] The adjustment valve 227a is not limited to being provided in the upstream branch pipe 223a, but may be provided in the downstream branch pipe 224a, or may be provided in both the upstream branch pipe 223a and the downstream branch pipe 224a. The same applies to the adjustment valve 227b.

[0156] (Bypass Valve 228) The bypass valve 228 is provided in the bypass pipe 225 that connects the upstream branch pipe 223a and the downstream branch pipe 224a.

[0157] [Control unit 230] The control unit 230 controls the heating device 3. Specifically, the control unit 230 controls the heat medium circuit 10 and the hot water circuit 220. Note that since the control unit 230 has the same configuration and functions as the control units 30 and 130, the description of the control unit 30 and 130 should be referred to, and detailed description of the control unit 230 will be omitted here.

[0158] According to the heating device of the third embodiment, as with the heating devices of the first and second embodiments, defrosting can be performed with a simple configuration in a heat pump type air conditioner by using the heat quantity of the heat medium contained in the heat exchange piping. Furthermore, according to the heating device of the third embodiment, the defrosting operation of the heat medium circuit can be performed by utilizing a larger amount of heat quantity of the heat medium contained in the piping.

[0159] Although the embodiments have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Various modifications and improvements, such as combinations and substitutions with part or all of other embodiments, are possible.

[0160] This application claims priority from basic patent application No. 2024-048193, filed with the Japan Patent Office on March 25, 2024, the entire contents of which are incorporated herein by reference.

[0161] REFERENCE SIGNS LIST 1, 2, 3 Heating device 10 Heat medium circuit 11 Compressor 12 Use side heat exchanger 13 Expansion valve 14 Heat source side heat exchanger 20 Hot water circuit 21, 121, 221 Upstream heat exchange piping 22, 122, 222 Downstream heat exchange piping 23a, 23b, 123a, 123b, 123c, 123ab, 223a, 223b Upstream branch piping 24a, 24b, 124a, 124b, 124c, 124ab, 224a, 224b Downstream branch piping 25, 125, 225 Bypass piping 26a, 26b, 126a, 126b, 126c, 226a, 226b Radiator 27a, 27b, 127a, 127b, 127c, 227a, 227b Control valves 28, 128, 228 Bypass valves 30, 130, 230 Control units HM1, HM2 Heat medium RMa, RMb, RM1a, RM1b, RM1c, RM2a, RM2b Temperature control target

Claims

1. A heat medium circuit (10) in which a compressor (11), a user-side heat exchanger (12) that performs heat exchange between a first heat medium (HM1) and a second heat medium (HM2), an expansion valve (13), and a heat source-side heat exchanger (14) are connected in a ring shape, and through which the first heat medium (HM1) flows; a hot water circuit (20) in which the second heat medium (HM2) that has undergone heat exchange in the user-side heat exchanger (12) flows, the hot water circuit comprising: an upstream heat exchange piping (21) connected to the user-side heat exchanger (12) and through which the second heat medium (HM2) flowing out of the user-side heat exchanger (12) flows; and a downstream heat exchange piping (22) connected to the user-side heat exchanger (12) and through which the second heat medium (HM2) flowing into the user-side heat exchanger (12) flows. a first radiator (26a) to which the second heat medium (HM2) is supplied and which heats a first temperature control target (RMa); a first control valve (27a) to adjust the second heat medium (HM2) flowing in the first radiator (26a); a first upstream branch pipe (23a) branched from the upstream heat exchange pipe (21) and connected to the first radiator (26a); a first downstream branch pipe (24a) branched from the downstream heat exchange pipe (22) and connected to the first radiator (26a); a second radiator (26b) to which the second heat medium (HM2) is supplied and which heats a second temperature control target (RMb); and a second control valve (27b) to adjust the second heat medium (HM2) flowing in the second radiator (26b). a second upstream branch pipe (23b) branching off from the upstream heat exchange pipe (21) and connected to the second radiator (26b); a second downstream branch pipe (24b) branching off from the downstream heat exchange pipe (22) and connected to the second radiator (26b); and a bypass valve (28) provided in a bypass pipe (25) connecting either between the first upstream branch pipe (23a) and the first downstream branch pipe (24a) or between the second upstream branch pipe (23b) and the second downstream branch pipe (24b); and a control unit (30) that controls the first adjustment valve (27a) and the second adjustment valve (27b) to be closed when a defrosting operation is performed in the heat medium circuit (10).

2. The heating device (1) according to claim 1, wherein the length of the piping from the utilization side heat exchanger (12) to the first radiator (26a) is longer than the length of the piping from the utilization side heat exchanger (12) to the second radiator (26b), and the bypass valve (28) is provided between the first upstream branch piping (23a) and the first downstream branch piping (24a).

3. The heating device (1) according to claim 1, wherein the bypass valve (28) is provided between the first upstream branch pipe (23 a) and the first downstream branch pipe (24 a), and the length of the pipe through which the second heat medium (HM2) flows from the use side heat exchanger (12) to the bypass valve (28) is longer than a first length, and the first length is a length such that the amount of heat stored in the second heat medium (HM2) contained in the pipe through which the second heat medium (HM2) flows from the use side heat exchanger (12) to the bypass valve (28) is equal to or greater than the amount of heat required for a defrosting operation in the heat medium circuit (10).

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