Hot water supply equipment

Abstract

To provide a water heater enabling sufficient sterilization of bath water.SOLUTION: A water heater 35 includes: a bath circulation pump 29 for circulating bath water in a bath circulation flow passage connected to a bathtub 30; UV generation means for irradiating the bath water flowing in the bath circulation flow passage with ultraviolet rays; a control section 36 controlling execution of a sterilization operation for circulating bath water in the bath circulation flow passage by using the bath circulation pump 29 and irradiating the bath water with ultraviolet rays by the UV generation means; and finish time setting means capable of setting finish time for finishing the sterilization operation. The control section 36 can selectively control execution of an intermittent operation mode of intermittently performing the sterilization operation and execution of a continuous operation mode of continuously performing the sterilization operation. The water heater 35 executes the sterilization operation in the intermittent operation mode from immediately after completion of hot water filling in the bathtub 30 to specified time that is time before the finish time only by a specified period, and executes the sterilization operation in the continuous operation mode from the specified time to the finish time.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a water heating apparatus. [Background technology]

[0002] Patent Document 1 discloses a bathtub device. This bathtub device is equipped with a water treatment unit for sterilizing and / or filtering the water in the bathtub, and a control unit for controlling the water treatment operation using the water treatment unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-71815 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the bathtub device disclosed in Patent Document 1 above, if a user takes a bath after the water has been filled and before the sterilization process begins, bacteria will grow in the water in the bathtub while the user is bathing, making it difficult to achieve sufficient sterilization.

[0005] The present disclosure has been made to solve the above-mentioned problems. An object of the present disclosure is to provide a water heater capable of sufficiently sterilizing bath water, which is hot water in a bathtub. [Means for solving the problem]

[0006] The hot water supply device according to the present disclosure includes a bath circulation pump that circulates bath water in a bath circulation flow path connected to a bathtub, a UV generating means that irradiates the bath water flowing in the bath circulation flow path with ultraviolet light, a control means that controls the execution of a sterilization operation in which the bath circulation pump circulates bath water in the bath circulation flow path and the UV generating means irradiates the bath water with ultraviolet light, and an end time setting means that can set an end time for ending the sterilization operation. The control means can selectively control the execution of an intermittent operation mode in which the sterilization operation is performed intermittently and a continuous operation mode in which the sterilization operation is performed continuously. The hot water supply device according to the present disclosure is characterized in that it executes the sterilization operation in the intermittent operation mode from immediately after the completion of filling the bathtub with water until a specified time that is a specified time before the end time, and executes the sterilization operation in the continuous operation mode from the specified time until the end time. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a water heating device capable of sufficiently sterilizing bath water. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a water heating device according to a first embodiment. [Diagram 2] 2 is a circuit configuration diagram during a sterilization operation in the hot water supply apparatus shown in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described with reference to the drawings. The same reference numerals are used to denote common or corresponding elements in each drawing, and the description will be simplified or omitted. In the following description, the terms "water", "hot water", "hot water", "warm water", and the like generally refer to liquid water, and may include anything from cold water to boiling water. In addition, in this disclosure, "sterilization" corresponds to inactivating at least a portion of germs and inhibiting their proliferation. In this disclosure, "germs" includes at least one of viruses, prokaryotes, pollen, fungi such as mold, and protozoa.

[0010] Embodiment 1 Fig. 1 is a diagram showing a water heating device according to embodiment 1. In this embodiment, a storage-type water heating device 35 having a hot water storage tank 8 will be described as an example, however, the water heating device according to the present disclosure is not limited to a storage-type water heating device, and may be, for example, an instantaneous water heating device that does not have a hot water storage tank.

[0011] As shown in Fig. 1, the hot water supply device 35 includes a tank unit 33, an HP (heat pump) unit 7, and a remote control 44. The HP unit 7 and the tank unit 33 are connected via an HP supply pipe 14, an HP return pipe 15, and electrical wiring (not shown). The tank unit 33 includes a control unit 36 ​​that corresponds to a control means. The operation of various valves, pumps, and the like included in the tank unit 33 and the HP unit 7 is controlled by the control unit 36 ​​that is electrically connected thereto.

[0012] In addition, the present disclosure is not limited to a configuration in which the operation of the water heating apparatus 35 is controlled by a single control unit 36, but may be configured in such a way that the operation of the water heating apparatus 35 is controlled by multiple control devices working together.

[0013] Remote control 44 has a function of accepting user operations related to operation commands and changes in set values. Remote control 44 is an example of a user interface. Control unit 36 ​​and remote control 44 are connected to each other via wire or wirelessly so that data can be communicated in both directions. Although not shown, remote control 44 has an operation unit such as a button or switch operated by the user. Remote control 44 may further have a display unit that displays information such as the status of water heating device 35. Remote control 44 may be equipped with a speaker, a microphone, etc. (not shown) and notify information to the user by voice or the like.

[0014] The HP unit 7 is an example of a heating means for heating water. The HP unit 7 includes a refrigerant circuit in which a compressor 1, a water-refrigerant heat exchanger 3, an expansion valve 4, and an air heat exchanger 6 are connected in a ring shape by refrigerant piping 5. The HP unit 7 operates a heat pump cycle using this refrigerant circuit. The HP unit 7 may also include an outside air temperature sensor 39 for detecting the outside air temperature.

[0015] In the water-refrigerant heat exchanger 3, heat is exchanged between the refrigerant compressed by the compressor 1 and water guided from the tank unit 33, thereby heating the water. The water-refrigerant heat exchanger 3 may be configured to exchange heat between the refrigerant compressed by the compressor 1 and water directly supplied from a water source such as a water tap.

[0016] The heating means in the present disclosure is not limited to the above-mentioned HP unit 7. The heating means may be, for example, a heat pump type, or may be one that uses fuel combustion heat as a heat source, one that uses solar heat as a heat source, one that uses waste heat from a fuel cell as a heat source, an electric heater disposed in the hot water tank 8, or one that uses a combination of multiple types of heat sources.

[0017] Hot water is stored in the hot water tank 8 built into the tank unit 33. Inside the hot water tank 8, temperature stratification is formed, with the upper side being hotter and the lower side being colder, due to differences in water density caused by temperature.

[0018] A third water supply pipe 9c is connected to a water inlet 8a provided at the bottom of the hot water storage tank 8. Water supplied from a water source such as a water supply through the first water supply pipe 9a is adjusted to a predetermined pressure by a pressure reducing valve 31 and flows into the hot water storage tank 8 through the third water supply pipe 9c. A hot water inlet outlet 8d for supplying hot water stored in the hot water storage tank 8 to the outside of the hot water supply device 35 and a hot water inlet outlet 8e that can communicate with the HP return pipe 15 are provided at the top of the hot water storage tank 8. A plurality of hot water temperature sensors 41, 42, and 43 are attached at different heights on the surface of the hot water storage tank 8. The hot water temperature sensor 41 is located at the same height as the medium temperature water inlet outlet 8f or at a height close to the medium temperature water inlet outlet 8f. The hot water temperature sensor 42 is located higher than the hot water temperature sensor 41. The hot water temperature sensor 43 is located lower than the hot water temperature sensor 41. By detecting the temperature distribution of the hot water in the hot water storage tank 8 using these hot water temperature sensors 41, 42, and 43, the control unit 36 ​​can calculate the amount of remaining hot water and the amount of stored heat in the hot water storage tank 8.

[0019] The control unit 36 ​​controls the boiling operation in which hot water heated by the HP unit 7 flows into the hot water storage tank 8. The control unit 36 ​​controls the start and stop of the boiling operation according to the amount of remaining hot water or the amount of heat stored in the hot water storage tank 8. The boiling operation is as follows. Low-temperature water flowing out from the bottom of the hot water storage tank 8 is guided to the HP unit 7 via the HP forward piping 14, heated in the water-refrigerant heat exchanger 3, and becomes hot water, i.e., high-temperature water. This high-temperature water flows into the hot water storage tank 8 from the hot water inlet outlet 8e at the top of the hot water storage tank 8 via the HP return piping 15. By performing such a boiling operation, high-temperature water is stored from the upper layer inside the hot water storage tank 8, and this high-temperature water layer gradually becomes thicker. The control unit 36 ​​ends the boiling operation when the amount of hot water or the amount of heat stored in the hot water storage tank 8 detected by the hot water storage temperature sensors 41, 42, and 43 exceeds a predetermined amount.

[0020] In the following description, the hot water stored in the hot water storage tank 8 may be referred to as "tank water." Also, the hot water stored in the bathtub 30 in the bathroom may be referred to as "bath water." The tank unit 33 contains a heat source pump 12, a bath heat exchanger 20, and a bath circulation pump 29. The heat source pump 12 is a pump for circulating hot water through various pipes, and is provided on the first water supply pipe 13a. The bath heat exchanger 20 exchanges heat between the tank water supplied from the hot water storage tank 8 and the bath water from the bathtub 30.

[0021] One end of the bath supply pipe 27 and one end of the bath return pipe 28 are connected to the bathtub adapter 80 installed in the bathtub 30. The other end of the bath supply pipe 27 and the other end of the bath return pipe 28 are connected to the bath heat exchanger 20. In this embodiment, the bath heat exchanger 20, the bath supply pipe 27, and the bath return pipe 28 form a bath circulation flow path.

[0022] A bath supply temperature sensor 37 is installed in the bath supply pipe 27 to detect the temperature of the bath water that has passed through the bath heat exchanger 20. A bath circulation pump 29 that circulates bath water in the bath circulation flow path, a bath return temperature sensor 38 that detects the temperature of the bath water before it leaves the bathtub 30 and enters the bath heat exchanger 20, a water level sensor 46 that detects the water level in the bathtub 30, and a flow rate sensor 47 are installed in the bath return pipe 28. The flow rate sensor 47 can detect the presence or absence of a flow of bath water and the flow rate of the bath water. When the bath circulation pump 29 is operated, the bath water in the bathtub 30 is drawn from the bathtub adapter 80 into the bath return pipe 28 and flows into the bath heat exchanger 20 through the bath return pipe 28. The bath water that has passed through the bath heat exchanger 20 passes through the bath supply pipe 27 and flows into the bathtub 30 from the bathtub adapter 80.

[0023] The tank unit 33 also includes a three-way valve 11, a four-way valve 16, and a four-way valve 18. The three-way valve 11 is a flow path switching means having inlets a and b, and an outlet c. The three-way valve 11 is configured to be capable of switching the flow path between two paths, ac and bc.

[0024] The four-way valve 16 is a flow path switching means having inlet ports a and b and outlet ports c and d. The four-way valve 16 is configured to be able to switch the flow paths among four paths, ac, ad, bc, and bd.

[0025] The four-way valve 18 is a flow path switching means having an inlet port a and outlet ports b, c, and d. The four-way valve 18 is configured to be able to switch the flow paths among three paths ab, ac, and ad.

[0026] The tank unit 33 also has a low-temperature pipe 10, a first water supply pipe 13a, a first hot water pipe 17a, a second hot water pipe 17b, a third hot water pipe 19a, a fourth hot water pipe 19b, and a fifth hot water pipe 19c. The low-temperature pipe 10 connects a water outlet 8b provided at the bottom of the hot water storage tank 8 to the a port of the three-way valve 11. The first water supply pipe 13a connects a c port of the three-way valve 11 to the inlet of the heat source pump 12. The outlet of the heat source pump 12 is connected to the inlet of the HP unit 7 by the HP forward pipe 14. The outlet of the HP unit 7 is connected to the b port of the four-way valve 16 by the HP return pipe 15. The first hot water pipe 17a connects a d port of the four-way valve 16 to the a port of the four-way valve 18. The second hot water pipe 17b connects the c port of the four-way valve 16 and a water inlet 8c provided at the bottom of the hot water storage tank 8. The third hot water pipe 19a connects the b port of the four-way valve 18 and a hot water inlet outlet 8e at the top of the hot water storage tank 8. The fourth hot water pipe 19b connects the d port of the four-way valve 18 and a hot water inlet outlet 8d provided at the top of the hot water storage tank 8. The fifth hot water pipe 19c connects the c port of the four-way valve 18 and a hot water inlet 8g provided between the top and the middle of the hot water storage tank 8.

[0027] The first tank circulation pipe 20a, which branches off from a midway position of the third hot water pipe 19a mentioned above, is connected to the inlet of the tank water of the bath heat exchanger 20. The outlet of the tank water of the bath heat exchanger 20 is connected to the b port of the three-way valve 11 by the second tank circulation pipe 20c. The second water supply pipe 13b, which branches off from the HP supply pipe 14 between the heat source pump 12 and the inlet of the HP unit 7, is connected to the a port of the four-way valve 16.

[0028] Furthermore, the tank unit 33 has a medium temperature piping 79, a first water supply piping 9a, a second water supply piping 9b, a third water supply piping 9c, a fourth water supply piping 9d, a hot water supply mixing valve 22, a bath mixing valve 23, a medium temperature water switching valve 78, a high temperature piping 21, a hot water supply piping 24, a bath piping 25, a return piping 20b and a check valve 50.

[0029] The medium-temperature water switching valve 78 is a flow path switching means having inlets a and b and an outlet c. The medium-temperature water switching valve 78 is configured to be able to switch the flow path between two paths, ac and bc.

[0030] The hot water supply mixing valve 22 is a mixing means having a first inlet, a second inlet, and an outlet. The bath mixing valve 23 is a mixing means having a first inlet, a second inlet, and an outlet.

[0031] One end of the first water supply pipe 9a is connected to a water source such as a water line. The other end of the first water supply pipe 9a is connected to the second water supply pipe 9b and the third water supply pipe 9c via the pressure reducing valve 31. These water supply pipes constitute a water supply line. The second water supply pipe 9b is connected to the a port of the medium temperature water switching valve 78. The medium temperature pipe 79 connects the medium temperature water inlet outlet 8f provided in the middle part of the hot water storage tank 8 to the b port of the medium temperature water switching valve 78. The return pipe 20b branches from the middle of the second tank circulation pipe 20c and is connected to the middle of the medium temperature pipe 79. The check valve 50 is installed on the return pipe 20b. The check valve 50 inhibits the flow from the middle part of the hot water storage tank 8 to the lower part of the hot water storage tank 8. One end of the fourth water supply pipe 9d is connected to the c port of the medium temperature water switching valve 78. The other end of the fourth water supply pipe 9d is connected to the first inlets of the hot water supply mixing valve 22 and the bath mixing valve 23. One end of the high temperature pipe 21 is connected to the hot water inlet outlet 8d of the hot water storage tank 8. The other end of the high temperature pipe 21 is connected to the second inlets of the hot water supply mixing valve 22 and the bath mixing valve 23.

[0032] The medium temperature water switching valve 78 is used by switching between two flow path states: a first flow path state in which the second water supply pipe 9b and the fourth water supply pipe 9d communicate with each other, and a second flow path state in which the medium temperature pipe 79 and the fourth water supply pipe 9d communicate with each other. When the medium temperature water switching valve 78 is in the first flow path state, low temperature water supplied from the water source passes through the second water supply pipe 9b and the fourth water supply pipe 9d and is supplied to the hot water supply mixing valve 22 and the bath mixing valve 23. When the medium temperature water switching valve 78 is in the second flow path state, medium temperature water supplied from the hot water storage tank 8 through the medium temperature pipe 79 passes through the fourth water supply pipe 9d and is supplied to the hot water supply mixing valve 22 and the bath mixing valve 23.

[0033] The hot water supply mixing valve 22 adjusts the flow rate ratio between high-temperature water supplied from the hot water storage tank 8 through the high-temperature piping 21 and low-temperature water or medium-temperature water supplied from the fourth water supply piping 9d, thereby generating hot water at a set temperature set by the user using the remote control 44, and causes the hot water to flow into the hot water supply piping 24. The hot water whose temperature has been adjusted by the hot water supply mixing valve 22 is supplied from the hot water supply piping 24 via the hot water tap 34 to a faucet (not shown) such as a shower or a faucet used by the user.

[0034] The bath mixing valve 23 can generate hot water at the set temperature set by the user via the remote control 44 by adjusting the flow rate ratio between the high-temperature water supplied from the hot water storage tank 8 through the high-temperature pipe 21 and the low-temperature water or medium-temperature water supplied from the fourth water supply pipe 9d. The hot water adjusted to the set temperature by the bath mixing valve 23 flows into the bath pipe 25, passes through the bath flow sensor 45 and the bath solenoid valve 26 installed on the bath pipe 25, the bath supply pipe 27, and the bath return pipe 28, and flows into the bathtub 30.

[0035] The control unit 36 ​​can determine the completion of filling the bathtub 30 with water based on information detected by the bath flow rate sensor 45 and the water level sensor 46. The control unit 36 ​​can control the amount of bath water to be filled, which is the amount of bath water in the bathtub 30 when filling is complete, to be equal to the amount of bath water set by the user via the remote control 44. The water heater 35 of this embodiment may be capable of automatic bath operation. When automatic bath operation is set via the remote control 44, the control unit 36 ​​controls each part of the water heater 35 to keep the bathtub 30 warm, increase the temperature, or cool the bathtub 30 after filling is complete, or to add hot water or cold water to the bathtub 30 so that the temperature and amount of bath water in the bathtub 30 are maintained at the temperature and amount set via the remote control 44.

[0036] The hot water supply device 35 of this embodiment further includes a fine bubble generator 48 that generates fine bubbles in the water flowing through the bath circulation flow path. In the illustrated example, the fine bubble generator 48 is disposed upstream of the sterilization device 49 in the bath circulation flow path. In this embodiment, in the circulation direction of the bath circulation flow path, the fine bubble generator 48 is located downstream of the flow sensor 47, the sterilization device 49 is located downstream of the fine bubble generator 48, and the bath heat exchanger 20 is located downstream of the sterilization device 49. In the present disclosure, the fine bubble generator 48 is not necessary.

[0037] The hot water supply device 35 of this embodiment may be capable of performing a bath heat recovery operation. The bath heat recovery operation is an operation for recovering the heat of the bath water remaining in the bathtub 30 into the hot water storage tank 8 after the end of bathing. During the bath heat recovery operation, the control unit 36 ​​operates the bath circulation pump 29 to circulate the bath water in the bathtub 30 through the bath circulation flow path. During the bath heat recovery operation, the following occurs. The three-way valve 11 is controlled so that the a port and the c port are connected and the b port is closed. As a result, the low-temperature pipe 10 is connected to the first water supply pipe 13a, and the flow path to the second tank circulation pipe 20c is blocked. The four-way valve 16 is controlled so that the a port and the d port are connected and the b port and the c port are closed. As a result, the second water supply pipe 13b is connected to the first hot water pipe 17a, and the flow path to the lower part of the hot water storage tank 8 is blocked by closing the second hot water pipe 17b side. The four-way valve 18 is controlled so that the a port and the b port are connected and the c port and the d port are closed, whereby the first hot water pipe 17a and the third hot water pipe 19a are connected, and the fourth hot water pipe 19b side and the fifth hot water pipe 19c side are closed, blocking the flow path to the intermediate part of the hot water storage tank 8.

[0038] In the bath heat recovery operation, the control unit 36 ​​performs control as follows. First, the bath circulation pump 29 is started to operate to start the circulation of bath water, and then the heat source pump 12 is started to operate while controlling the three-way valve 11, the four-way valve 16, and the four-way valve 18 as described above. The tank water is circulated as follows. The low-temperature tank water flowing out of the water outlet 8b of the hot water storage tank 8 through the low-temperature pipe 10 flows into the bath heat exchanger 20 through the three-way valve 11, the first water supply pipe 13a, the heat source pump 12, the second water supply pipe 13b, the four-way valve 16, the first hot water pipe 17a, the four-way valve 18, the third hot water pipe 19a, and the first tank circulation pipe 20a. In the bath heat exchanger 20, the tank water is heated by the heat of the bath water from the bathtub 30, and becomes close to the temperature of the bath water in the bathtub 30. This heated tank water is hereinafter referred to as "heat recovery hot water". The heat recovery hot water flows from the bath heat exchanger 20 through the return pipe 20b, the check valve 50, and the medium temperature pipe 79, and into the hot water storage tank 8 from the medium temperature water inlet outlet 8f. When the bath heat recovery operation is performed, the heat recovery hot water is stored in the hot water storage tank 8 near the medium temperature water inlet outlet 8f.

[0039] The flow rate of water circulating through the bath circulation flow path is hereinafter referred to as the "bath water circulation flow rate." The control unit 36 ​​may adjust the bath water circulation flow rate by adjusting the rotation speed of the bath circulation pump 29. The higher the rotation speed of the bath circulation pump 29, the higher the bath water circulation flow rate.

[0040] The hot water supply device 35 of this embodiment is equipped with a sterilization device 49. The sterilization device 49 has a UV generation means for irradiating the water in the bath circulation flow path with ultraviolet rays. The UV generation means may be, for example, an ultraviolet LED (Light Emitting Diode) as an ultraviolet ray source, or a low-pressure mercury lamp as an ultraviolet ray source. In the illustrated example, the sterilization device 49 is disposed midway through the bath return pipe 28, but the sterilization device 49 may also be disposed midway through the bath supply pipe 27.

[0041] The hot water supply device 35 of this embodiment can perform a sterilization operation. The control unit 36 ​​controls the execution of the sterilization operation. The sterilization operation is an operation in which the bath water is circulated in the bath circulation flow path by the bath circulation pump 29 while the UV generating means of the sterilization device 49 irradiates the bath water with ultraviolet rays. In the sterilization operation, the control unit 36 ​​operates the bath circulation pump 29 and turns on the UV generating means of the sterilization device 49. When the sterilization operation is performed, the bath water in the bathtub 30 is drawn from the bathtub adapter 80 into the bath return pipe 28 and is irradiated with ultraviolet rays while passing through the sterilization device 49. The bath water is sterilized by the ultraviolet rays acting on the DNA of bacteria contained in the bath water. The sterilized bath water passes through the bath heat exchanger 20 and the bath supply pipe 27 and flows into the bathtub 30 from the bathtub adapter 80. By performing the sterilization operation, the bath water in the bathtub 30 can be sterilized.

[0042] Fig. 2 is a circuit diagram of the hot water supply device 35 shown in Fig. 1 during sterilization operation. As shown in Fig. 2, during sterilization operation, the control unit 36 ​​operates the bath circulation pump 29 to circulate the bath water in the bathtub 30 through the bath circulation flow path. During sterilization operation, the control unit 36 ​​operates the UV generation means of the sterilization device 49 to irradiate ultraviolet rays onto the bath water circulating through the bath circulation flow path.

[0043] Furthermore, hot water supply device 35 of the present embodiment is configured to be able to set an end time for ending the sterilization operation. For example, remote control 44 is provided with a button or the like constituting an end time setting means for setting this end time. In the present embodiment, the user can set the end time for ending the sterilization operation by operating the end time setting means of remote control 44.

[0044] The hot water supply device 35 of the present embodiment is configured to be capable of selectively operating in an intermittent operation mode in which the sterilization operation is performed intermittently, and in a continuous operation mode in which the sterilization operation is performed continuously. The control unit 36 ​​can selectively control the hot water supply device 35 to operate in the intermittent operation mode or the continuous operation mode.

[0045] The hot water supply device 35 of this embodiment is characterized in that it executes a sterilization operation in an intermittent operation mode immediately after the bathtub 30 is filled with hot water. That is, the control unit 36 ​​controls each part of the hot water supply device 35 so that the sterilization operation in the intermittent operation mode is executed immediately after the bathtub 30 is filled with hot water. By executing the sterilization operation immediately after the bathtub is filled, the growth of bacteria in the bath water can be suppressed even if the user takes a bath immediately after the bathtub is filled. Furthermore, by performing the sterilization operation intermittently, the discomfort of the user can be suppressed even if the user takes a bath. Furthermore, by performing the sterilization operation intermittently, the operating time of the sterilization operation that is unnecessary and unnecessary can be reduced when the user does not take a bath.

[0046] The sterilization operation in the intermittent operation mode is performed from immediately after the hot water is filled to a specified time that is a specified time before the set end time. From this specified time to the end time, the hot water supply device 35 performs the sterilization operation in the continuous operation mode. Note that the above-mentioned specified time may be set in advance at the time of design or construction, may be set arbitrarily by the user, or may be set automatically by the hot water supply device 35 based on the device information of the hot water supply device 35.

[0047] By performing sterilization operation in the continuous operation mode after suppressing the proliferation of bacteria through sterilization operation in the intermittent operation mode, it is possible to further reduce bacteria and obtain sufficiently sterilized bath water. The sufficiently sterilized bath water can be used for washing, for example. According to this embodiment, sufficiently sterilized bath water can be used for washing, and a sense of cleanliness can be guaranteed when using bath water for washing. Furthermore, by using bath water for washing, it is possible to reduce the amount of water used from the tap when washing.

[0048] According to the above embodiment, it is possible to provide water heater 35 capable of sufficiently sterilizing bath water.

[0049] In addition, the sterilization operation in the continuous operation mode until the end time is particularly effective when bath water is used for washing. In cases where bath water is not used for washing, the sterilization operation in the continuous operation mode until the end time does not necessarily have to be performed. Therefore, the water heater 35 may be configured to be able to set whether or not to perform the sterilization operation in the continuous operation mode from a specified time to an end time in order to correspond to the purpose of use of the user. For example, the remote control 44 may be provided with a button or the like constituting a setting means that can set whether or not to perform the sterilization operation in the continuous operation mode from a specified time to an end time. When the user uses bath water for washing, the user may set the execution of the continuous operation mode to yes. When the user does not use bath water for washing, the user may set the execution of the continuous operation mode to no and use only the sterilization operation in the intermittent operation mode in order to suppress the growth of bacteria during bathing. The intermittent operation mode, which is performed immediately after filling the water, can reduce the odor during bathing or the turbidity of the bath water.

[0050] For example, hot water supply device 35 may be configured to be able to set a specified time that is the time for which the sterilization operation in the continuous operation mode is performed. For example, remote control 44 may be provided with a button or the like that constitutes a time setting means for setting the specified time that is the time for which the sterilization operation in the continuous operation mode is performed. By operating the time setting means, a user can cause hot water supply device 35 to perform a sterilization operation according to his or her needs.

[0051] For example, the water heater 35 may be configured to automatically calculate and set the specified time, which is the time for performing the sterilization operation in the continuous operation mode, based on the device information of each device constituting the water heater 35. For example, the control unit 36 ​​of the water heater 35 may be provided with a function as a time calculation means for automatically calculating and setting the specified time based on the device information. The time calculation means calculates the specified time based on the difference in the usage situation of the water heater 35. Note that the function of the time calculation means may be provided in a control device other than the control unit 36. The specified time can be calculated based on at least one parameter that is device information of the water heater 35, such as the set amount of hot water for filling the bathtub 30, the current water level or amount of hot water in the bathtub 30, the bath water circulation flow rate, and the number of people who have bathed in the bathtub 30 after filling the bathtub 30. The number of people who have bathed in the bathtub 30 can be measured by, for example, the water level sensor 46 or a human detection means such as a human sensor provided separately. The specified time may be automatically calculated as the time required to sufficiently sterilize the bathwater based on each of the above parameters. For example, when the set amount of hot water for filling the bath, the water level and amount of hot water in the bathtub, or the number of people bathing is large, the bath water becomes dirty. Therefore, when the set amount of hot water for filling the bath, the water level and amount of hot water in the bathtub, or the number of people bathing is large, the specified time may be calculated to be longer than when these are low.

[0052] The method for setting the above-mentioned specified time, i.e., the operation time in the continuous operation mode, may be selectable by the user. Water heating device 35 may be provided with a selection means for the user to select whether the specified time is the time set by the above-mentioned time setting means or the time set by the time calculation means. By allowing the user to select whether the operation time in the continuous operation mode is set arbitrarily or automatically, it is possible to accommodate the needs of each user.

[0053] Furthermore, the hot water supply device 35 may be configured to be able to display to the user whether the sterilization operation is being performed in the intermittent operation mode or the continuous operation mode. For example, the remote control 44 may be provided with a display means for displaying, on a screen or by voice, whether the sterilization operation is being performed in the intermittent operation mode or the continuous operation mode. [Explanation of symbols]

[0054] 1 compressor, 3 water-refrigerant heat exchanger, 4 expansion valve, 5 refrigerant piping, 6 air heat exchanger, 7 HP unit, 8 hot water storage tank, 8a water inlet, 8b water outlet, 8c water inlet, 8d hot water inlet outlet, 8e hot water inlet outlet, 8f medium temperature water inlet outlet, 8g hot water inlet, 9a first water supply pipe, 9b second water supply pipe, 9c third water supply pipe, 9d fourth water supply pipe, 10 low temperature pipe, 11 three-way valve, 12 heat source pump, 13a first water supply pipe, 13b second water supply pipe, 14 HP forward pipe, 15 HP return pipe, 16 four-way valve, 17a first hot water pipe, 17b second hot water pipe, 18 four-way valve, 19a third hot water pipe, 19b fourth hot water piping, 19c fifth hot water piping, 20 bath heat exchanger, 20a first tank circulation piping, 20b return piping, 20c second tank circulation piping, 21 high temperature piping, 22 hot water mixing valve, 23 bath mixing valve, 24 hot water piping, 25 bath piping, 26 bath solenoid valve, 27 bath supply piping, 28 bath return piping, 29 bath circulation pump, 30 bathtub, 31 pressure reducing valve, 33 tank unit, 34 hot water tap, 35 hot water supply device, 36 control unit, 37 bath supply temperature sensor, 38 bath return temperature sensor, 39 outside air temperature sensor, 41 hot water storage temperature sensor, 42 hot water storage temperature sensor, 43 hot water storage temperature sensor, 44 remote control, 45 bath flow rate sensor, 46 water level sensor, 47 flow rate sensor, 48 fine bubble generator, 49 sterilization device, 50 check valve, 78 medium temperature water switching valve, 79 medium temperature piping, 80 bathtub adapter

Claims

1. A bath circulation pump that circulates bath water through a bath circulation flow path connected to the bathtub; UV generating means for irradiating ultraviolet rays onto the bath water flowing through the bath circulation flow path; A control means for controlling the execution of a sterilization operation in which bath water is circulated through the bath circulation flow path by the bath circulation pump and ultraviolet light is irradiated onto the bath water by the UV generation means; An end time setting means capable of setting an end time for ending the sterilization operation; Equipped with The control means is capable of selectively controlling the execution of an intermittent operation mode in which the sterilization operation is performed intermittently and the execution of a continuous operation mode in which the sterilization operation is performed continuously, A hot water supply device characterized in that the sterilization operation is performed in the intermittent operation mode from immediately after the bathtub has been filled with water until a specified time that is a specified time before the end time, and the sterilization operation is performed in the continuous operation mode from the specified time until the end time.

2. The hot water supply apparatus according to claim 1 , further comprising a setting unit capable of setting whether or not the sterilization operation is to be performed in the continuous operation mode from the specified time until the end time.

3. 3. The hot water supply apparatus according to claim 1, further comprising a time setting means for allowing a user to set the specified time, which is the time for which the sterilization operation in the continuous operation mode is performed.

4. 3. The hot water supply apparatus according to claim 1, further comprising a time calculation means for automatically calculating and setting the specified time, which is the time for which the sterilization operation is performed in the continuous operation mode, based on device information.

5. a time setting means for allowing a user to set the specified time, which is the time for which the sterilization operation in the continuous operation mode is performed; a time calculation means for automatically calculating and setting the specified time, which is the time for which the sterilization operation in the continuous operation mode is performed, based on device information; 3. The hot water supply device according to claim 1, further comprising a selection means for allowing a user to select whether the specified time is the time set by the time setting means or the time set by the time calculation means.

6. The water heating device of claim 4 or claim 5, wherein the time calculation means calculates the specified time from at least one parameter among the set amount of hot water to be filled, the water level in the bathtub, the amount of hot water in the bathtub, the flow rate of bath water circulated through the bath circulation flow path by the bath circulation pump, and the number of people bathing in the bathtub.

7. 3. The hot water supply apparatus according to claim 2, wherein the setting means is provided in a remote control which is a user interface for accepting operations by a user.

8. 4. The hot water supply apparatus according to claim 3, further comprising a remote controller, which is a user interface for accepting operations by a user, and which is provided with a time setting means.

9. 6. The hot water supply apparatus according to claim 5, wherein the selection means is provided on a remote control which is a user interface for accepting operations by a user.

10. The hot water supply device according to any one of claims 1 to 9, further comprising a display means for displaying whether the sterilization operation is being performed in the intermittent operation mode or the sterilization operation is being performed in the continuous operation mode.

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