Hybrid type water warmer

Abstract

To achieve a reduction in the size of a water warmer even when it is equipped with a hot water supply part, a tank part, and a heat pump part.SOLUTION: A hybrid type water warmer 1 according to the present invention has a hot water supply part 2, a tank part 3, and a heat pump part 4. The heat pump part 4 has, on a circulation path 44 where heat medium is circulated, a compressor 40 for compressing the heat medium, a water-heat exchange part 41 for carrying out heat exchange between heat of the compressed heat medium and hot water flowing through a tank outgoing pipe 33 and a tank return pipe 34, an expansion valve 42 for expanding the heat medium subjected to heat exchange, and a heat absorbing part 43 for making the expanded heat medium absorb heat of outside air. The hot water supply part 2 has an exhaustion path 9 used for exhausting combustion exhaust of a gas burner 6 which passed through a heat exchanger 7. The heat absorbing part 43 is disposed in the exhaustion path 9.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a hybrid hot water appliance that combines a water heater equipped with a gas burner and capable of heating passing water, and a tank equipped with a heat pump and storing the heated hot water. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a heat pump-type hot water supply system has been in practical use, which includes a heat pump and a tank for storing hot water heated by the heat pump, and supplies the hot water in the tank to a kitchen, a bathroom, or the like. In this hot water supply system, the heat pump operates during times when hot water usage is relatively low to heat the water in the tank, and when the hot water tap is opened or a command is given to fill the bathtub, hot water is supplied from the tank. Therefore, in order to supply the required amount of hot water to the bathtub, the tank needs to be sized to be able to store a large amount of hot water. Therefore, Patent Document 1 discloses an invention for a hybrid hot water supply system in which a burner heating device, which is a water heater, is installed in the supply line downstream of a tank that stores hot water heated by a heat pump, and the burner heating device is activated when the temperature of the water supplied from the tank is lower than the hot water supply set temperature or when there is a small amount of hot water in the tank when filling it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-224762 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned conventional hybrid hot water supply system, the capacity of the tank can be made relatively small by using the water heater as an auxiliary heat source, and the tank can be made smaller to some extent. However, because this system has three independent units, the hot water supply unit, the tank unit, and the heat pump unit, it is unavoidable that the system is large in size, making it difficult to install in houses or apartment buildings where the space between the building and the exterior is narrow. For this reason, there is a demand for further miniaturization even in hybrid systems.

[0005] Therefore, an object of the present disclosure is to provide a hybrid hot water appliance that can be made compact even while including a hot water supply section, a tank section, and a heat pump section. [Means for solving the problem]

[0006] In order to achieve the above object, the present disclosure provides a hot water supply unit including a gas burner, a heat exchanger that exchanges heat between the water flowing therethrough and the combustion exhaust heat of the gas burner, a water supply pipe connected to the inlet side of the heat exchanger, a hot water outlet pipe connected to the outlet side of the heat exchanger, and a fan that supplies combustion air to the gas burner; a tank section including a tank connected to the water supply pipe, capable of storing water supplied from the water supply pipe and capable of supplying the stored water to the water supply pipe, and a tank side pipe for supplying hot and cold water in and out of the tank; This is a hybrid hot water equipment having a heat pump section including a compressor that compresses the heat medium, a water heat exchange section that exchanges heat between the compressed heat medium and hot water flowing through the tank side piping, an expansion valve that expands the heat-exchanged heat medium, and a heat absorption section that causes the expanded heat medium to absorb heat from the outside air, located on a circulation path through which the heat medium circulates. The hot water supply section has an exhaust passage through which the combustion exhaust gas of the gas burner that has passed through the heat exchanger is discharged, and the heat absorption section is disposed within the exhaust passage. Another aspect of the present disclosure is characterized in that, in the above configuration, the system further includes a control unit that controls the combustion of the gas burner, the operation of the fan, and the operation of the heat pump unit, and the control unit operates the fan when only the heat pump unit is operated. Effect of the Invention

[0007] According to the present disclosure, the heat absorption section of the heat pump section is incorporated within the exhaust passage of the hot water supply section, so that miniaturization can be achieved even though the device includes a hot water supply section, a tank section, and a heat pump section. According to another aspect of the present disclosure, in addition to the above effects, when only the heat pump unit is operated, the control unit operates the fan, so that the heat remaining in the exhaust passage can be absorbed by the heat absorption unit and used to heat the hot water in the tank. Therefore, the hot water supply efficiency can be improved compared to conventional hybrid hot water equipment. In addition, the fan of the hot water supply unit is also provided with the function of sending outside air to the heat absorption unit, which leads to further miniaturization. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a hybrid hot water device. [Diagram 2] FIG. 13 is a schematic diagram of a modified example of the hybrid hot water equipment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a hybrid water heater (hereinafter simply referred to as "water heater") according to the present disclosure. The hot water equipment 1 includes a hot water supply section 2, a tank section 3, and a heat pump section 4. First, the hot water supply section 2 will be described. The hot water supply section 2 has a gas burner 6 arranged on the lower side within the combustion chamber 5, and a heat exchanger 7 arranged on the upper side within the combustion chamber 5. A fan 8 is provided on the lower side of the combustion chamber 5 for supplying combustion air to the gas burner 6. An exhaust passage 9 is provided on the upper side of the combustion chamber 5 for discharging the combustion exhaust gas that has passed through the heat exchanger 7 to the outside.

[0010] The heat exchanger 7 is of a fin tube type in which a heat transfer tube 10 penetrates in a serpentine manner through fins 11, 11, ..., which are arranged at a predetermined interval in the thickness direction. A water supply pipe 12 is connected to the inlet end of the heat transfer tube 10. An external water pipe (not shown) is connected to the inlet of the water supply pipe 12. A hot water outlet pipe 13 is connected to the outlet end of the heat exchanger 7. An external pipe having a plurality of hot water taps 14, 14·· provided in the washroom, kitchen, and bathroom is connected to the outlet of the hot water outlet pipe 13. A bypass pipe 15 that bypasses the heat exchanger 7 is connected between the water supply pipe 12 and the hot water outlet pipe 13. The water supply pipe 12 is provided with a flow rate sensor 16 that detects the flow rate of water flowing through the water supply pipe 12, and an inlet water temperature sensor 17 that detects the temperature of water flowing through the water supply pipe 12. In the hot water outlet pipe 13, outlet hot water temperature sensors 18a, 18b that detect the outlet hot water temperature are provided on the upstream and downstream sides of the bypass pipe 15, respectively. The bypass pipe 15 is provided with a water volume control valve 19 that controls the volume of water flowing through the bypass pipe 15. A main valve 20, a proportional valve 21, and a main valve 22 are provided in a gas pipe that supplies fuel gas to the gas burner 6 from the upstream side.

[0011] The tank section 3 includes a tank 30 disposed near the water supply pipe 12. The capacity of the tank 30 here is 10L to 30L. A tank water inlet pipe 31 is connected between an inlet provided at the bottom of the tank 30 and the water supply pipe 12. The tank water inlet pipe 31 branches off from the water supply pipe 12 and supplies water into the tank 30. A tank hot water outlet pipe 32 is connected between an outlet provided at the top of the tank 30 downstream of the tank water inlet pipe 31 and the water supply pipe 12. The tank hot water outlet pipe 32 supplies hot water in the tank 30 that overflows due to water entering from the tank water inlet pipe 31 to the water supply pipe 12. A tank supply pipe 33 is connected to the upper part of the tank 30. The tank supply pipe 33 is connected to the downstream end of a water-side piping 46 of a water heat exchange section 41 (described later) of the heat pump section 4. A tank return pipe 34 is connected to the lower part of the tank 30. The tank return pipe 34 is connected to the upstream end of the water-side piping 46. The tank return pipe 34 is provided with a pump 35 and a return temperature sensor 36 that detects the temperature of the hot and cold water in the tank return pipe 34. The tank supply pipe 33 and the tank return pipe 34 are an example of the tank-side piping of the present disclosure.

[0012] The heat pump section 4 includes a compressor 40, a water heat exchange section 41, an expansion valve 42, a heat absorption section 43, and a loop-shaped circulation path 44 that connects these in series. A heat medium (e.g., an alternative fluorocarbon) can circulate through the circulation path 44. The compressor 40 compresses the heat medium that has absorbed heat in the heat absorption section 43 , and sends the high-temperature and high-pressure heat medium to the water-heat exchange section 41 . The water heat exchange section 41 includes a hot side pipe 45 and a water side pipe 46. The hot side pipe 45 is incorporated in the circulation path 44. The water side pipe 46 is connected to the tank supply pipe 33 and the tank return pipe 34 as described above, forming a tank circulation path 47 through which the hot water in the tank 30 circulates. When the pump 35 is operated, the hot water in the tank 30 circulates through the tank circulation path 47, and heat exchange is performed between the heat medium flowing in the hot side pipe 45 and the hot water flowing in the water side pipe 46. The expansion valve 42 reduces the pressure of the heat medium from which heat has been removed in the water-heat exchange section 41 , and sends the reduced-temperature, low-pressure heat medium to the heat absorption section 43 . Heat absorption section 43 exchanges heat between the outside air and the heat medium, and here it is disposed in exhaust passage 9 penetrating combustion chamber 5 of hot water supply section 2 .

[0013] In the hot water equipment 1 configured as above, the hot water supply unit 2, the tank unit 3, and the heat pump unit 4 are controlled by a controller 50. Detection signals from each sensor are input to the controller 50. The controller 50 controls the operation of each valve, the pump 35 of the tank unit 3, and the compressor 40 based on instructions from a remote control 51 and information obtained from each sensor. The controller 50 is an example of a control unit of the present disclosure. First, when any of the hot water taps 14 is opened, tap water is supplied from the external piping to the water supply pipe 12. This tap water branches into the tank inlet pipe 31, flows into the tank 30, returns to the water supply pipe 12 from the tank outlet pipe 32, merges with the tap water in the water supply pipe 12, and flows through the appliance. When the flow rate sensor 16 detects the flow of water in the appliance, the controller 50 opens the main valve 20 and the main valve 22 to ignite the gas burner 6. Thus, in the heat exchanger 7, heat exchange takes place between the water flowing in the heat transfer pipe 10 and the combustion exhaust gas of the gas burner 6, and hot water is discharged from the hot water outlet pipe 13.

[0014] Based on the flow rate obtained from flow rate sensor 16 and the inlet water temperature obtained from inlet water temperature sensor 17, controller 50 controls the opening of proportional valve 21 and the rotation speed of fan 8 to target the set temperature indicated by remote control 51. Based on the outlet hot water temperature obtained from outlet hot water temperature sensors 18a, 18b, controller 50 also controls the opening of proportional valve 21 and the rotation speed of fan 8 so that hot water is dispensed at the set temperature, and adjusts the opening of water volume control valve 19 in bypass pipe 15, if necessary, to mix hot water from bypass pipe 15 with hot water in outlet hot water pipe 13. When the hot water tap 14 is closed and the controller 50 detects that water flow through the appliance has stopped via the flow sensor 16, the controller 50 closes the main valve 20 and the main valve 22 to stop combustion in the gas burner 6 and also stops the rotation of the fan 8.

[0015] In addition, the controller 50 operates the compressor 40 and the pump 35 of the tank unit 3 at the same time as supplying hot water. Then, in the heat pump unit 4, the heat medium is compressed by the compressor 40 to become high temperature and high pressure, dissipates heat in the water heat exchange unit 41, becomes low temperature and low pressure in the expansion valve 42, and circulates through the circulation path 44 while absorbing heat in the heat absorption unit 43. At this time, in the heat absorption section 43 in the exhaust passage 9, the heat medium can absorb heat from the combustion exhaust gas passing through the exhaust passage 9. Therefore, the temperature of the heat medium can be increased by effectively utilizing the combustion exhaust heat. Meanwhile, in the tank section 3, the pump 35 is operated to circulate the hot water in the tank 30 through the tank circulation path 47. Then, in the water heat exchange section 41, heat exchange takes place between the heat medium flowing in the heat side piping 45 and the hot water flowing in the water side piping 46. Thus, the hot water in the tank 30 is heated as it passes through the water heat exchange section 41. Specifically, the hot water in the tank 30 is once heated to a high temperature (e.g., 75°C), and then the compressor 40 is turned ON / OFF based on the temperature detected by the return temperature sensor 36 to maintain the water at a predetermined insulation temperature (e.g., 65°C). Therefore, the water flowing in the water supply pipe 12 is mixed with the hot water in the tank 30 via the tank water inlet pipe 31 and the tank hot water outlet pipe 32. The controller 50 monitors the inlet water temperature after mixing using the inlet water temperature sensor 17, and controls the opening of the proportional valve 21 and the rotation speed of the fan 8 with the set temperature as the target.

[0016] Then, when the remote control 51 instructs the heat pump unit 4 to operate independently after the hot water supply unit 2 stops dispensing hot water, the controller 50 operates the compressor 40 and the pump 35 of the tank unit 3, and rotates the fan 8 at a predetermined rotation speed. Then, the hot water in the tank 30 circulates through the tank circulation path 47, is heated as it passes through the water heat exchanger 41, and is maintained at a predetermined heat retention temperature. At this time, in the combustion chamber 5, the fan 8 exhausts the combustion exhaust gas remaining in the combustion chamber 5 from the exhaust passage 9. Therefore, in the heat absorption section 43 in the exhaust passage 9, the heat medium can absorb heat from the combustion exhaust gas passing through the exhaust passage 9. Therefore, even when the heat pump section 4 is operating alone, the heat medium can be raised in temperature by effectively utilizing the combustion exhaust heat. When the hot water tap 14 is opened in this state, the hot water in the tank 30 is discharged from the water supply pipe 12 through the heat transfer pipe 10 and the hot water discharge pipe 13 of the heat exchanger 7 without the gas burner 6 being ignited.

[0017] Thus, the hot water appliance 1 of the above embodiment has a hot water supply section 2 including a gas burner 6, a heat exchanger 7 that exchanges heat between the water passing through it and the combustion exhaust heat of the gas burner 6, a water supply pipe 12 connected to the inlet side of the heat exchanger 7, a hot water outlet pipe 13 connected to the outlet side of the heat exchanger 7, and a fan 8 that supplies combustion air to the gas burner 6. The hot water appliance 1 also has a tank 30 that is connected to the water supply pipe 12 and can store water supplied from the water supply pipe 12 and can supply the stored water to the water supply pipe 12, and a tank section 3 that includes a tank supply pipe 33 and a tank return pipe 34 that flow hot water in and out of the tank 30. Furthermore, the hot water equipment 1 has a heat pump section 4 on a circulation path 44 through which the heat medium circulates, the heat pump section 4 including a compressor 40 that compresses the heat medium, a water heat exchange section 41 that exchanges heat between the heat of the compressed heat medium and hot water flowing through the tank supply pipe 33 and the tank return pipe 34, an expansion valve 42 that expands the heat medium that has been heat exchanged, and a heat absorption section 43 that causes the expanded heat medium to absorb heat from the outside air. Hot water supply section 2 has an exhaust passage 9 through which the combustion exhaust gas of gas burner 6 that has passed through heat exchanger 7 is discharged, and heat absorption section 43 is disposed within exhaust passage 9. According to this configuration, heat absorption section 43 of heat pump section 4 is incorporated within exhaust passage 9 of hot water supply section 2, so that even if hot water supply section 2, tank section 3 and heat pump section 4 are provided, a compact size can be achieved.

[0018] In particular, the controller 50, which controls the combustion of the gas burner 6, the operation of the fan 8, and the operation of the heat pump unit 4, operates the fan 8 when only the heat pump unit 4 is operated, so that the heat remaining in the exhaust passage 9 can be absorbed by the heat absorption unit 43 and used to heat the hot water in the tank 30. This improves the hot water supply efficiency compared to conventional hybrid hot water appliances. Also, the fan 8 of the hot water supply unit 2 is provided with the function of sending outside air to the heat absorption unit 43, which leads to further miniaturization.

[0019] Modifications of the present disclosure will be described below. In the above embodiment, the tank 30 is connected in parallel to the water supply pipe 12, and the water from the water supply pipe 12 and the hot water in the tank 30 are mixed and sent to the heat exchanger 7, but as shown in Fig. 2, the tank 30 may be connected in series to the water supply pipe 12. In this case as well, feedforward control is performed based on the inlet water temperature obtained from the inlet water temperature sensor 17. In Fig. 2, the bypass pipe 15 that bypasses the heat exchanger 7 and the outlet water temperature sensor 18b downstream of the bypass pipe 15 are omitted, but the bypass pipe 15 and the outlet water temperature sensor 18b may be provided as in Fig. 1. In the embodiment shown in Figures 1 and 2, hot water in tank 30 flows into water supply pipe 12 at the same time as hot water supply unit 2 is used, but a switching valve may be provided in tank water inlet pipe 31 to allow the selection of water supply only from water supply pipe 12 or water supply from both tank 30 and water supply pipe 12. In the above embodiment, after the end of the independent use of hot water supply unit 2, the rotation of fan 8 is stopped at the same time as the combustion of gas burner 6 is stopped, but it is also possible to rotate only fan 8 for a predetermined period of time after the combustion of gas burner 6 is stopped. In this case, the residual heat in combustion chamber 5 can be transferred to the atmosphere in exhaust passage 9, and the next time heat pump unit 4 is operated independently, more effective heat absorption in heat absorption unit 43 is possible.

[0020] The capacity of the tank is not limited to 10 to 30 L as in the above embodiment, and may be increased or decreased as appropriate. The heat exchanger of the water heater may be a combination of a primary heat exchanger that recovers sensible heat and a secondary heat exchanger that recovers latent heat. In this case, the heat absorption section of the heat pump section may be disposed in the exhaust passage between the primary heat exchanger and the secondary heat exchanger, or may be disposed in the exhaust passage downstream of the secondary heat exchanger. A drop pipe connected to the bathtub may be branched off from the hot water outlet pipe, and a switching valve installed on the drop pipe may be used to fill the bathtub with hot water. In this case, a bath heater may be installed in parallel with the hot water supply unit so that the hot water in the bathtub can be reheated by the bath heater. [Explanation of symbols]

[0021] 1· Hybrid hot water equipment, 2· Hot water supply section, 3· Tank section, 4· Heat pump section, 5· Combustion chamber, 6· Gas burner, 7· Heat exchanger, 8· Fan, 9· Exhaust passage, 12· Water supply pipe, 13· Hot water outlet pipe, 14· Hot water tap, 16· Flow sensor, 30· Tank, 31· Tank inlet pipe, 32· Tank outlet pipe, 33· Tank supply pipe, 34· Tank return pipe, 35· Pump, 40· Compressor, 41· Water heat exchange section, 43· Heat absorption section, 44· Circulation path, 45· Heat side piping, 46· Water side piping, 47· Tank circulation path, 50· Controller, 51· Remote control.

Claims

1. a hot water supply unit including a gas burner, a heat exchanger for exchanging heat between the water passing through the heat exchanger and the combustion exhaust heat of the gas burner, a water supply pipe connected to the inlet side of the heat exchanger, a hot water outlet pipe connected to the outlet side of the heat exchanger, and a fan for supplying combustion air to the gas burner; a tank section including a tank connected to the water supply pipe, capable of storing water supplied from the water supply pipe and capable of supplying the stored water to the water supply pipe, and a tank side pipe for supplying hot and cold water in and out of the tank; A hybrid hot water device having a heat pump unit including a compressor that compresses the heat medium, a water heat exchange unit that exchanges heat between the compressed heat medium and hot water flowing through the tank side piping, an expansion valve that expands the heat medium that has been heat exchanged, and a heat absorption unit that causes the expanded heat medium to absorb heat from outside air, on a circulation path through which the heat medium circulates, The hot water supply unit has an exhaust passage through which the combustion exhaust gas of the gas burner that has passed through the heat exchanger is discharged, A hybrid water heater, characterized in that the heat absorption portion is disposed within the exhaust passage.

2. The hybrid hot water equipment according to claim 1, further comprising a control unit that controls the combustion of the gas burner, the operation of the fan, and the operation of the heat pump unit, and the control unit operates the fan when only the heat pump unit is operated.

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