JP6921203B2 - Hot water heater - Google Patents

Description

The present invention relates to a hot water supply device that supplies hot water to a bathtub.

In recent years, the sophistication of hot water supply devices has progressed, and hot water supply devices that not only generate hot water but also adjust the hot water supply temperature to an appropriate temperature and fill a bathtub with an appropriate amount of hot water are known. Further, there is also known a hot water supply device that reheats the hot water in the bathtub by transporting the hot water in the bathtub to the hot water supply device by using a pump and exchanging heat with the hot water generated by the hot water supply device.

Further, Patent Document 1 proposes a hot water supply device that realizes energy saving by exchanging heat between the hot water in the bathtub and the hot water in the hot water storage tank provided in the hot water supply device and recovering the heat of the hot water in the bathtub. ing. Further, Patent Document 2 proposes a hot water supply device that cleans the inside of a bathtub by heating the hot water in the bathtub and generating fine bubbles to circulate the inside of the bathtub.

Japanese Patent No. 5126432 Japanese Unexamined Patent Publication No. 2016-48130

Here, in order to save energy and improve convenience, a hot water supply device capable of performing both heat recovery and bathtub cleaning is desired. However, when both heat recovery and bathtub cleaning are carried out, there is a risk that the number of parts will increase, the size of the device will increase, and the product cost will increase as the functions increase.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hot water supply device capable of performing both heat recovery and bathtub cleaning while suppressing an increase in product cost.

The hot water supply device according to the present invention has a hot water storage tank for storing hot water, a heat exchanger for exchanging heat between the hot water in the hot water storage tank and hot water in the bathtub, and a bathtub for hot water flowing out of the bathtub via the heat exchanger. The bathtub circulation path that returns to the bathtub, the tank circulation path that returns the hot water that has flowed out of the hot water storage tank to the hot water storage tank via the heat exchanger, and the bathtub circulation path that circulates the hot water in the bathtub to the bathtub circulation path. A bathtub circulation pump to be used, a tank circulation pump provided in the tank circulation path to circulate the hot water in the hot water storage tank to the tank circulation path, and a heat recovery operation and a bathtub to recover the heat of the hot water in the bathtub to the hot water in the hot water storage tank. It is equipped with a control device that performs a cleaning operation to clean the inside, and the bathtub circulation pump is driven in both the heat recovery operation and the cleaning operation, the tank circulation pump is driven in the heat recovery operation, and is added in the cleaning operation. Hot water in the bathtub containing the agent circulates in the bathtub circulation path, and the control device simultaneously performs both the heat recovery operation and the cleaning operation according to the operation of either the cleaning switch or the heat recovery switch. ..

According to the hot water supply device according to the present invention, the bathtub circulation pump is driven in both the heat recovery operation and the washing operation, and the hot water in the bathtub is circulated in the bathtub circulation path. In this way, by using a common configuration for the heat recovery operation and the cleaning operation, both heat recovery and bathtub cleaning can be performed while suppressing an increase in the number of parts and an increase in product cost due to an increase in the size of the equipment. Can be done.

It is a schematic block diagram of the hot water supply apparatus in Embodiment 1. FIG. It is a figure which shows the hardware configuration of a control device. It is a functional block diagram of a control device. It is a figure which shows the flow of hot water during a heat recovery operation. It is a figure which shows the flow of hot water during a washing operation. It is a flowchart which shows the flow of the heat recovery operation and the cleaning operation in Embodiment 1. FIG. It is a flowchart which shows the flow of the heat recovery operation and the cleaning operation in Embodiment 2. It is a flowchart which shows the flow of the heat recovery operation and the cleaning operation in Embodiment 3.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure used in this specification, the common element shall have the same designation. Further, in the present specification, "hot water" is a general term for hot water (hot water) and water.

Embodiment 1.
FIG. 1 is a schematic configuration diagram of a hot water supply device 100 according to a first embodiment of the present invention. The hot water supply device 100 of the present embodiment heats the low temperature water supplied from the water supply end 101, and supplies hot water at a temperature desired by the user from the hot water supply end 102. The hot water supply end 102 is a water supply port, a faucet or a shower head of a bathroom tub 200, a faucet of a washroom or a kitchen, or the like.

The hot water supply device 100 heats the heat pump unit 110 that heats the low temperature water, the hot water storage tank 120 that stores the high temperature water heated by the heat pump unit 110, and the hot water in the hot water storage tank 120 and the hot water in the bathtub 200. A switch 130 is provided. Further, the hot water supply device 100 passes the hot water flowing out of the bathtub 200 to the bathtub 200 via the heat exchanger 130 and the hot water flowing out of the hot water storage tank 120 via the heat exchanger 130. It is provided with a tank circulation path 150 for returning to the hot water storage tank 120. Further, the hot water supply device 100 includes a control device 160 that controls the operation of the entire hot water supply device 100, and a remote controller 170. Although not essential in the present invention, the hot water supply device 100 further circulates hot water in the hot water storage tank 120 via the heat pump unit 110, and supplies hot water in the hot water storage tank 120 to the bathtub 200. It is equipped with routes and a three-way valve, on-off valve, check valve, etc. provided on each route.

The heat pump unit 110 is _{a refrigeration cycle device that uses, for example, CO 2} or HFC (hydrofluorocarbon) as a refrigerant. The heat pump unit 110 includes a compressor, a first heat exchanger that exchanges heat between the refrigerant and water, an expansion valve, a second heat exchanger that exchanges heat between the outside air and the refrigerant, a blower, and a temperature sensor. It is composed of a control board and the like. The compressor, the first heat exchanger, the expansion valve and the second heat exchanger are connected in an annular shape to form a refrigeration cycle circuit (also referred to as a refrigerant circuit) for circulating the refrigerant.

The hot water storage tank 120 is a cylindrical tank made of metal such as stainless steel or resin. A heat insulating material (not shown) is arranged on the outside of the hot water storage tank 120. As a result, the hot water can be kept warm in the hot water storage tank 120 for a long time. The lower part of the hot water storage tank 120 is connected to the water supply end 101 via a pipe provided with a pressure reducing valve 103. Then, the low-temperature water supplied from the water supply end 101 is adjusted to a predetermined pressure by the pressure reducing valve 103 and flows into the hot water storage tank 120. Further, the lower portion and the upper portion of the hot water storage tank 120 are connected to the heat pump unit 110 via a boiling path. As a result, the low-temperature water flowing out from the lower part of the hot water storage tank 120 is heat-exchanged by the first heat exchanger of the heat pump unit 110 to become high-temperature water, and is returned to the upper part of the hot water storage tank 120. A boiling circuit is constructed by such circulation. Further, inside the hot water storage tank 120, a temperature stratification is formed in which the temperature of the hot water is higher toward the upper side and the temperature of the hot water is lower toward the lower side in the vertical direction.

Further, on the surface of the hot water storage tank 120, a plurality of hot water storage temperature sensors 121 and 122 are attached at different heights. The hot water storage temperature sensors 121 and 122 detect the temperature distribution of hot water in the hot water storage tank 120. The detection results of the hot water storage temperature sensors 121 and 122 are transmitted to the control device 160, and the control device 160 grasps the amount of hot water stored in the hot water storage tank 120 and uses it for controlling the start and stop of the boiling operation described later. The number of hot water storage temperature sensors is not limited to two, and three or more may be provided.

The heat exchanger 130 exchanges heat between the hot water in the bathtub 200 and the hot water in the hot water storage tank 120. More specifically, the heat exchanger 130 is provided on the bathtub circulation path 140 and the tank circulation path 150, and exchanges heat between the hot water flowing through the bathtub circulation path 140 and the hot water flowing through the tank circulation path 150.

The bathtub circulation path 140 is a pipe connecting the hot water supply device 100 and the bathtub 200. The bathtub circulation path 140 includes a bathtub return pipe 141 and a bathtub outbound pipe 142. Further, a bathtub circulation pump 145 for circulating hot water in the bathtub is provided on the bathtub circulation path 140. By driving the bathtub circulation pump 145, hot water can be circulated between the hot water supply device 100 and the bathtub 200. Specifically, by driving the bathtub circulation pump 145, the hot water in the bathtub 200 flows into the hot water supply device 100 via the bathtub return pipe 141, and the bathtub again from the hot water supply device 100 via the bathtub going pipe 142. Return to 200.

Further, the bathtub going pipe 142 is provided with an addition device 148 that adds an additive to the hot water in the bathtub 200 during the washing operation. The additive device 148 adds the additive to the hot water in the bathtub 200 according to the control signal from the control device 160. As the additive, one having a surface active effect is used. In this way, the cleaning effect of the bathtub 200 can be enhanced by circulating hot water containing the additive in the bathtub 200 during the cleaning operation.

The tank circulation path 150 is a pipe that connects the lower part and the middle part of the hot water storage tank 120 via the heat exchanger 130. The tank circulation path 150 is provided with a tank circulation pump 155 for transporting the hot water of the hot water storage tank 120 to the heat exchanger 130. Further, the tank circulation path 150 is provided with a three-way valve 151, a first four-way valve 152, and a second four-way valve 153. By switching the three-way valve 151, the first four-way valve 152, and the second four-way valve 153, the circulation path of hot water in the hot water storage tank 120 is switched.

The bathtub circulation pump 145 and the tank circulation pump 155 include an inverter circuit (not shown) and are driven according to a control signal transmitted from the control device 160. By changing the drive rotation speed of the bathtub circulation pump 145 and the tank circulation pump 155, the amount of hot water flowing through the bathtub circulation path 140 and the tank circulation path 150 can be changed.

The control device 160 is communicably connected to each part of the hot water supply device 100. The control device 160 controls each part of the hot water supply device 100 in response to a user operation on the remote controller 170. Specifically, the control device 160 controls the operation of the heat pump unit 110, the bathtub circulation pump 145, the tank circulation pump 155 and the addition device 148, and the switching of the three-way valve 151, the first four-way valve 152 and the second four-way valve 153. do. Further, the control device 160 causes the remote controller 170 to display the operating state of the hot water supply device 100, the operation screen, and the like. The details of the control device 160 will be described later.

The remote controller 170 includes a display unit that displays an operating state of the hot water supply device 100 and an operation unit that accepts a user's operation on the hot water supply device 100. The operating unit includes a bathtub cleaning switch 171 that instructs the start of the cleaning operation. The operation on the remote controller 170 is transmitted to the controller 160.

Next, the configuration of the control device 160 of the hot water supply device 100 will be described in detail. FIG. 2 is a diagram showing a hardware configuration of the control device 160. As shown in FIG. 2, the control device 160 includes a CPU (Central Processing Unit) 601, a communication interface 602, a ROM (Read Only Memory) 603, a RAM (Random Access Memory) 604, and a secondary storage device 605. To be equipped. The CPU 601 and the communication interface 602, the ROM 603, the RAM 604, and the secondary storage device 605 are connected to each other via the bus 606. The CPU 601 controls the control device 160 in an integrated manner. Details of the functions realized by the CPU 601 will be described later.

The communication interface 602 includes a NIC (Network Interface Card controller) for performing wired communication or wireless communication. The communication interface 602 is communicably connected to the remote controller 170, the heat pump unit 110, the bathtub circulation pump 145, the tank circulation pump 155, and the addition device 148. The control device 160 receives a user's operation on the remote controller 170 via the communication interface 602, and transmits a control signal to each part of the hot water supply device via the communication interface 602.

The ROM 603 stores a plurality of firmwares or data or the like used when executing these firmwares. The RAM 604 is used as a work area of the CPU 601.

The secondary storage device 605 is composed of a readable / writable non-volatile semiconductor memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) or a flash memory, a hard disk drive, or the like. The secondary storage device 605 stores programs for controlling the operation of the hot water supply device 100, data used when executing these programs, and the like. The data used when executing the program includes various parameters used for controlling each operation mode of the hot water supply device 100, data indicating control of the bathtub circulation pump 145 and the tank circulation pump 155, and the like.

FIG. 3 is a functional block diagram of the control device 160. As shown in FIG. 3, the control device 160 includes a user interface unit 611, a device state acquisition unit 612, a device control unit 613, and an operation mode execution unit 614 as functional units. Each of these functional units is realized by the CPU 601 executing one or a plurality of programs stored in the secondary storage device 605.

The user interface unit 611 performs user interface processing via the remote controller 170. That is, the user interface unit 611 accepts a user operation on the remote controller 170. Further, the user interface unit 611 transmits information to be presented to the user (for example, information indicating the operating state of the hot water supply device 100) to the remote controller 170, and causes the remote controller 170 to display the information.

The equipment state acquisition unit 612 acquires data such as an operating state and a measured temperature from the heat pump unit 110 at regular intervals such as 30 seconds, and acquires data indicating a driving state from the bathtub circulation pump 145 and the tank circulation pump 155. do. Further, the device state acquisition unit 612 acquires the temperature of the hot water in the hot water storage tank 120 from the hot water storage temperature sensors 121 and 122.

The device control unit 613 controls the operation of the entire hot water supply device 100 according to the user operation via the remote controller 170. Specifically, the equipment control unit 613 transmits a control signal to the heat pump unit 110 to control the compressor, the expansion valve, the blower, and the like. Further, in the heat recovery operation and the cleaning operation, the equipment control unit 613 transmits a control signal to the bathtub circulation pump 145, the tank circulation pump 155, and the addition device 148 to control the operation and stop. Further, the equipment control unit 613 transmits a control signal to the three-way valve 151, the first four-way valve 152, and the second four-way valve 153 to switch the flow path.

The operation mode execution unit 614 causes the device control unit 613 to execute the control corresponding to the operation mode selected by the user operation via the remote controller 170. Specifically, the operation mode execution unit 614 reads the control of the heat pump unit 110 corresponding to the selected operation mode, or the bathtub circulation pump 145 and the tank circulation pump 155 from the secondary storage device 605, and executes the control in the equipment control unit 613. Let me. The operation mode to be selected includes a boiling operation, a heat recovery operation, a bathtub washing operation, and the like.

Subsequently, the heat recovery operation and the cleaning operation in the hot water supply device 100 of the present embodiment will be described. The heat recovery operation is an operation for the hot water supply device 100 to recover the heat of the hot water in the bathtub 200, and the washing operation is an operation for cleaning the bathtub 200.

<Heat recovery operation>
First, the heat recovery operation by the hot water supply device 100 of the present embodiment will be described. FIG. 4 is a diagram showing the flow of hot water during the heat recovery operation. In the heat recovery operation, both the bathtub circulation pump 145 and the tank circulation pump 155 are driven, and hot water flows through both the bathtub circulation path 140 and the tank circulation path 150. First, the flow of hot water in the bathtub 200 will be described. The hot water that has left the bathtub 200 passes through the bathtub return pipe 141, is boosted by the bathtub circulation pump 145, and is sent to the heat exchanger 130. Then, the hot water flowing out of the heat exchanger 130 returns to the bathtub 200 again through the bathtub going pipe 142.

Subsequently, the flow of hot water in the hot water storage tank 120 will be described. The hot water flowing out from the lower part of the hot water storage tank 120 passes through the three-way valve 151 and is boosted by the tank circulation pump 155. The hot water boosted by the tank circulation pump 155 then flows from the first four-way valve 152 to the second four-way valve 153 and flows into the heat exchanger 130. Then, the hot water flowing out of the heat exchanger 130 flows into the hot water storage tank 120 from the central part of the hot water storage tank 120. When the three-way valve 151, the first four-way valve 152, and the second four-way valve 153 are open in a specific direction, it is assumed that the three-way valve 151, the first four-way valve 152, and the second four-way valve 153 are not open in the other direction. During the heat recovery operation, the three-way valve 151, so that hot water flows in the order of the hot water storage tank 120, the three-way valve 151, the tank circulation pump 155, the first four-way valve 152, the second four-way valve 153, the heat exchanger 130, and the hot water storage tank 120. The first four-way valve 152 and the second four-way valve 153 are switched.

In the heat exchanger 130, the hot water in the bathtub 200 and the hot water in the hot water storage tank 120 exchange heat. As a result, when the temperature of the hot water in the bathtub 200 is higher than the temperature of the hot water in the lower part of the hot water storage tank 120, the heat of the hot water in the bathtub 200 can be recovered to the hot water in the hot water storage tank 120.

<Washing operation>
Subsequently, the cleaning operation by the hot water supply device 100 of the present embodiment will be described. FIG. 5 is a diagram showing the flow of hot water during the washing operation. In the washing operation, the bathtub circulation pump 145 is driven and hot water flows through the bathtub circulation path 140. The hot water that has left the bathtub 200 passes through the bathtub return pipe 141, is boosted by the bathtub circulation pump 145, and is sent to the heat exchanger 130. Then, the hot water flowing out of the heat exchanger 130 returns to the bathtub 200 again via the bathtub going pipe 142. By circulating hot water in this way, the bathtub 200 can be washed by the water flow generated in the bathtub 200. Further, when the washing operation is performed, the additive is added to the hot water in the bathtub 200 from the addition device 148. As a result, the hot water containing the additive circulates in the bathtub 200, so that the cleaning effect of the bathtub 200 can be enhanced.

Further, since it is not necessary to exchange heat between the hot water in the bathtub 200 and the hot water in the hot water storage tank 120 during the washing operation, the tank circulation pump 155 is not driven. Therefore, the hot water in the hot water storage tank 120 does not circulate in the tank circulation path 150.

As described above, the hot water supply device 100 of the present embodiment can carry out both a heat recovery operation and a cleaning operation. Further, in both the heat recovery operation and the washing operation, the bathtub circulation pump 145 and the bathtub circulation path 140 are used. As described above, by using the common configuration in the heat recovery operation and the cleaning operation, it is not necessary to provide a circulation path and a circulation pump for each operation. As a result, both the heat recovery operation and the cleaning operation can be performed while suppressing an increase in the number of parts of the hot water supply device 100, an increase in the size of the device, and an increase in product cost associated therewith. Further, by using a common configuration for the heat recovery operation and the cleaning operation, it is possible to prevent the control from becoming complicated, and the heat recovery operation and the cleaning operation can be efficiently performed.

Here, when a common configuration is used in the heat recovery operation and the cleaning operation as in the present embodiment, the heat recovery operation and the cleaning operation interfere with each other depending on the usage pattern of the user, and the operation can be optimized. There is no fear. Therefore, the hot water supply device 100 of the present embodiment automatically controls the timing of performing the heat recovery operation and the cleaning operation to optimize the operation.

FIG. 6 is a flowchart showing the flow of the heat recovery operation and the cleaning operation in the present embodiment. The flowchart of FIG. 6 is realized by the CPU 601 executing one or more programs stored in the secondary storage device 605. First, it is determined whether or not the start of the washing operation is instructed (S11). Here, it is determined that the start of the cleaning operation is instructed by operating the bathtub cleaning switch 171 of the remote controller 170. Then, when the start of the cleaning operation is instructed (S11: YES), the three-way valve 151, the first four-way valve 152, and the second four-way valve are operated by the equipment control unit 613 so that the hot water in the hot water storage tank 120 flows through the tank circulation path 150. The flow path of the valve 153 is switched (S12). Then, according to the control signal from the device control unit 613, the additive is added from the addition device 148 to the hot water in the bathtub 200 (S13).

Then, the bathtub circulation pump 145 and the tank circulation pump 155 are driven by the equipment control unit 613 (S14). As a result, the hot water in the bathtub 200 circulates in the bathtub circulation path 140, and the hot water in the hot water storage tank 120 circulates in the tank circulation path 150. At this time, the heat exchanger 130 exchanges heat between the hot water in the bathtub 200 and the hot water in the hot water storage tank 120. As a result, the heat of the hot water in the bathtub 200 is recovered by the hot water in the hot water storage tank 120, and the heat recovery operation is performed. Further, the washing operation is carried out by circulating the hot water to which the additive is added in the bathtub circulation path 140 and the bathtub 200.

Then, when the predetermined time T has elapsed (S15: YES), the bathtub circulation pump 145 and the tank circulation pump 155 are stopped by the equipment control unit 613 (S16), and the heat recovery operation and the cleaning operation are completed. The predetermined time T is preset and stored in the secondary storage device 605. Alternatively, the predetermined time T may be arbitrarily set by the user, or may be variable according to the device state acquired by the device state acquisition unit 612.

As described above, in the present embodiment, the heat recovery operation and the cleaning operation are simultaneously performed according to the operation of one switch, that is, the bathtub cleaning switch 171. As a result, it is possible to realize simplification of operation and shortening of the operation time of the bathtub circulation pump 145 as compared with the case where each operation is performed separately. As a result, it is possible to optimize the operation and reduce the power consumption.

Further, when an additive is added to the hot water in the bathtub 200, the flow path resistance of the bathtub circulation path 140 is reduced due to the surface active effect of the additive. As a result, the input of the bathtub circulation pump 145 can be suppressed at the same circulation flow rate as compared with the case where the heat recovery operation is performed alone. Therefore, the heat recovery operation with high energy saving is possible as compared with the case where the heat recovery operation is carried out independently.

The timing of stopping the bathtub circulation pump 145 and the tank circulation pump 155 is not limited to the elapse of a predetermined time T. For example, when the temperature of the hot water in the bathtub 200 becomes a predetermined temperature (for example, 30 ° C.) or less, the bathtub circulation pump 145 and the tank circulation pump 155 may be stopped. Alternatively, when the difference between the temperature of the hot water in the bathtub 200 and the temperature of the hot water stored in the lower part of the hot water storage tank 120 detected by the hot water storage temperature sensor 122 disappears, the bathtub circulation pump 145 and the tank circulation pump 155 May be stopped. Further, instead of stopping the bathtub circulation pump 145 and the tank circulation pump 155 at the same time, one of the bathtub circulation pump 145 and the tank circulation pump 155 may be stopped earlier than the other.

Embodiment 2.
Next, Embodiment 2 of the present invention will be described. The present embodiment differs from the first embodiment in the timing at which the heat recovery operation and the cleaning operation are performed. The configuration of the hot water supply device 100 and the flow of hot water during the heat recovery operation and the bathtub cleaning are the same as those in the first embodiment.

FIG. 7 is a flowchart showing the flow of the heat recovery operation and the cleaning operation in the present embodiment. In the present embodiment, the heat recovery operation is started after the start of the washing operation. First, it is determined whether or not the start of the washing operation is instructed (S21). Here, it is determined that the start of the cleaning operation is instructed by operating the bathtub cleaning switch 171 of the remote controller 170 as in the first embodiment. Then, when the start of the washing operation is instructed (S21: YES), the device control unit 613 transmits a control signal to the addition device 148, and the addition device 148 adds the additive to the hot water in the bathtub 200 (S22). .. Then, the bathtub circulation pump 145 is driven by the device control unit 613 (S23). As a result, the hot water containing the additive circulates in the bathtub circulation path 140 and the bathtub 200, so that the washing operation is carried out.

Then, the washing operation is continued until the predetermined time T ₁ elapses (S24: NO). When the predetermined time T ₁ has elapsed (S24: YES), the three-way valve 151, the first four-way valve 152, and the second four-way valve are operated by the equipment control unit 613 so that the hot water in the hot water storage tank 120 flows through the tank circulation path 150. The flow path of 153 is switched (S25). Then, the tank circulation pump 155 is driven by the device control unit 613 (S26), and the hot water in the hot water storage tank 120 circulates in the tank circulation path 150. As a result, in the heat exchanger 130, heat is exchanged between the hot water in the bathtub 200 and the hot water in the hot water storage tank 120, and the heat recovery operation is performed.

Then, the washing operation and the heat recovery operation are continued until the predetermined time T _{2 elapses (S27: NO).} When the predetermined time T ₂ has elapsed (S27: YES), the bathtub circulation pump 145 and the tank circulation pump 155 are stopped by the equipment control unit 613 (S28), and the heat recovery operation and the cleaning operation are completed.

As described above, in the present embodiment, the cleaning operation and the heat recovery operation are continuously performed according to the operation of one switch. During the washing operation, the higher the temperature of the hot water in the bathtub 200, the higher the cleaning effect. Further, by carrying out the heat recovery operation, the temperature of the hot water in the bathtub 200 is lowered. Therefore, by performing the heat recovery operation after starting the cleaning operation as in the present embodiment, the water temperature during cleaning can be kept high, and a high cleaning effect can be expected.

The timing of driving the tank circulation pump 155 is not limited to _{the time after a predetermined time T 1 has elapsed after driving the bathtub circulation pump 145.} For example, the timing for driving the tank circulation pump 155 may be determined by the temperature of the hot water stored in the hot water storage tank 120 or the bathtub 200. Specifically, when the temperature of the hot water stored in the bathtub 200 is 35 ° C. or lower, or the temperature difference between the hot water stored in the bathtub 200 and the hot water stored in the lower part of the hot water storage tank 120 is 5 ° C. or less. In addition, the tank circulation pump 155 may be driven to start the heat recovery operation. As a result, the minimum amount of heat recovery can be secured in the heat recovery operation. Further, instead of stopping the bathtub circulation pump 145 and the tank circulation pump 155 at the same time, one of the bathtub circulation pump 145 and the tank circulation pump 155 may be stopped earlier than the other.

Embodiment 3.
Next, Embodiment 3 of the present invention will be described. The present embodiment differs from the first embodiment in the timing at which the heat recovery operation and the cleaning operation are performed. The configuration of the hot water supply device 100 and the flow of hot water during the heat recovery operation and the bathtub cleaning are the same as those in the first embodiment.

FIG. 8 is a flowchart showing the flow of the heat recovery operation and the cleaning operation in the present embodiment. In the present embodiment, the cleaning operation is performed after the start of the heat recovery operation. First, it is determined whether or not the start of the washing operation is instructed (S31). Here, it is determined that the start of the cleaning operation is instructed by pressing the bathtub cleaning switch 171 of the remote controller 170, as in the first embodiment. Then, when the start of the cleaning operation is instructed (S31: YES), the three-way valve 151, the first four-way valve 152, and the second four-way valve 152 are operated by the device control unit 613 so that the hot water in the hot water storage tank 120 flows through the tank circulation path 150. The flow path of the four-way valve 153 is switched (S32).

Then, the bathtub circulation pump 145 and the tank circulation pump 155 are driven by the equipment control unit 613 (S33). As a result, the hot water in the bathtub 200 circulates in the bathtub circulation path 140, and the hot water in the hot water storage tank 120 circulates in the tank circulation path 150. Then, in the heat exchanger 130, heat exchange between the hot water in the bathtub 200 and the hot water in the hot water storage tank 120 is performed, and the heat recovery operation is carried out.

Then, the heat recovery operation is continued until the predetermined time T _{3 elapses (S34: NO).} Then, when the predetermined time T ₃ has elapsed (S34: YES), a control signal is transmitted from the device control unit 613 to the addition device 148, and the additive is added to the hot water in the bathtub 200 from the addition device 148 (S35). .. At this time, the hot water in the bathtub 200 has already circulated in the bathtub circulation path 140, but the cleaning operation with a high cleaning effect is started by adding the additive.

After that, when the predetermined time T ₄ elapses (S36: YES), the tank circulation pump 155 is stopped (S37), and the heat recovery operation ends. Then, when the predetermined time T ₅ elapses (S38: YES), the bathtub circulation pump 145 is stopped (S39), and the washing operation ends.

As described above, in the present embodiment, the heat recovery operation and the cleaning operation are continuously performed by operating one switch. Depending on the type of additive added in the bathtub 200, the heat transfer performance in the heat exchanger 130 may be impaired. In this case, even if the heat recovery operation is performed in the situation where the additive is added to the bathtub 200, a high heat recovery effect cannot be expected. Therefore, by carrying out the cleaning operation after starting the heat recovery operation as in the present embodiment, it is possible to suppress the deterioration of the heat transfer performance of the heat exchanger 130 during heat recovery, and a high energy saving effect can be expected.

The timing of adding the additive after driving the bath circulation pump 145 and the tank circulation pump 155, is not limited to after the lapse of a predetermined time T _3. The timing of adding the additive may be determined by the temperature of the hot water stored in the hot water storage tank 120 or the bathtub 200. Specifically, when the temperature of the hot water stored in the bathtub 200 becomes a predetermined temperature (for example, 35 ° C.) or less, an additive may be added to ensure the cleaning effect. Alternatively, when the temperature difference between the hot water stored in the bathtub 200 and the hot water stored in the lower part of the hot water storage tank 120 is within 2 ° C., no further heat recovery effect can be expected, and even if an additive is added. good.

_{Further, the tank circulation pump 155 is stopped when a predetermined time T 4} elapses after the additive is added to the bathtub 200, but the present invention is not limited to this. For example, the timing of stopping the tank circulation pump 155 may be determined by the temperature of the hot water stored in the hot water storage tank 120 or the bathtub 200, or the power consumption of the tank circulation pump 155. For example, when the temperature difference between the hot water stored in the bathtub 200 and the hot water stored in the lower part of the hot water storage tank 120 is within 2 ° C., no further heat recovery effect can be expected, and the tank circulation pump 155 is stopped. The heat recovery operation may be terminated. Alternatively, when the power reduced by the heat recovery amount derived from the temperature of the hot water stored in the bath 200 and the temperature of the hot water stored in the lower part of the hot water storage tank 120 is smaller than the power consumption of the tank circulation pump 155, the tank The circulation pump 155 may be stopped and the heat recovery operation may be terminated.

The present invention is not limited to the above-described embodiment, and various modifications and applications are possible without departing from the gist of the present invention. For example, although the hot water supply device 100 of the first to third embodiments is a heat pump hot water supply device that uses the heat pump unit 110 as the heat source machine, an electric heater or gas combustion may be used as the heat source instead of the heat pump unit 110.

Further, in the first to third embodiments, it is determined that the start of the cleaning operation is instructed by pressing the bathtub cleaning switch 171 of the remote controller 170, and the cleaning operation and the heat recovery operation are performed simultaneously or continuously. Although it is configured, it is not limited to this. For example, the remote controller 170 includes both a bathtub cleaning switch 171 and a bathtub heat recovery switch (not shown), and when either switch is pressed, the cleaning operation and the heat recovery operation are performed simultaneously or continuously. It may be carried out. Further, the bathtub cleaning switch 171 and the bathtub heat recovery switch (not shown) are not limited to physical switches, and may be software keys or voice instructions. Further, the remote controller 170 of the hot water supply device 100 is not an indispensable configuration, and the control device 160 may be configured to be communicable with an external terminal other than the remote controller 170. Then, the instruction to start the washing operation may be transmitted from an external terminal. Further, the instruction of the cleaning operation or the heat recovery operation is not limited to the instruction from the user, and is automatically instructed by the operation mode execution unit 614 based on the schedule information and the like stored in the secondary storage device 605. It may be what is done.

Further, the additive device 148 of the hot water supply device 100 is not an indispensable configuration, and the additive may be added into the bathtub 200 by the user. As an example of the cleaning method of the bathtub 200 using the hot water supply device 100 in this case, the user first adds an additive to the hot water in the bathtub 200, and then operates the bathtub cleaning switch 171 to perform a heat recovery operation and a cleaning operation. May be carried out at the same time. Alternatively, the washing operation may be carried out without adding additives. Further, instead of the addition device 148, a device for generating air bubbles that enhances the cleaning effect may be provided. In this case as well, bubbles are generated in the hot water in the bathtub 200 according to the control signal of the control device 160, similarly to the addition device 148.

100 hot water supply device, 101 water supply end, 102 hot water supply end, 103 pressure reducing valve, 110 heat pump unit, 120 hot water storage tank, 121, 122 hot water storage temperature sensor, 130 heat exchanger, 140 bath circulation path, 141 bath return pipe, 142 bath going pipe 145 tub circulation pump, 148 addition device, 150 tank circulation path, 151 three-way valve, 152 first four-way valve, 153 second four-way valve, 155 tank circulation pump, 160 control device, 170 remote controller, 171 tub cleaning switch, 200 Water heater, 601 CPU, 602 communication interface, 603 ROM, 604 RAM, 605 secondary storage device, 606 bus, 611 user interface unit, 612 equipment status acquisition unit, 613 equipment control unit, 614 operation mode execution unit.

Claims (5)

A hot water storage tank that stores hot water and
A heat exchanger that exchanges heat between the hot water in the hot water storage tank and the hot water in the bathtub.
A bathtub circulation path for returning hot water flowing out of the bathtub to the bathtub via the heat exchanger, and
A tank circulation path for returning the hot water flowing out of the hot water storage tank to the hot water storage tank via the heat exchanger, and
A bathtub circulation pump provided in the bathtub circulation path and circulating hot water in the bathtub in the bathtub circulation path.
A tank circulation pump provided in the tank circulation path and circulating hot water in the hot water storage tank in the tank circulation path.
A control device for performing a heat recovery operation for recovering the heat of the hot water in the bathtub to the hot water in the hot water storage tank and a washing operation for cleaning the inside of the bathtub is provided.
In both the heat recovery operation and the cleaning operation, the bathtub circulation pump is driven.
In the heat recovery operation, the tank circulation pump is driven.
In the washing operation, the hot water in the bathtub containing the additive circulates in the bathtub circulation path.
The control device is a hot water supply device that simultaneously performs both the heat recovery operation and the cleaning operation in response to the operation of either the cleaning switch or the heat recovery switch. Before SL controller after the start of the washing operation, when a predetermined time has elapsed, when the temperature difference between the hot water stored in the lower portion of the hot water and the hot water storage tank in the bath is equal to or less than a predetermined temperature Or, when the power reduced by the amount of heat recovered from the temperature of the hot water in the bathtub and the temperature of the hot water stored in the lower part of the hot water storage tank is smaller than the power consumption of the tank circulation pump, the heat. The hot water supply device according to claim 1, wherein the recovery operation is terminated. The cleaning during operation, the hot water supply device according to the additive to enhance the cleaning effect to claim 1 or 2, further comprising an additive system added to the hot water in the bathtub. The hot water supply device according to any one of claims 1 to 3, wherein the additive has a surface-active effect. A method for cleaning a bathtub using the hot water supply device according to claim 1.
A step of adding the additives to enhance the cleaning effect on the hot water in the bathtub,
A method for cleaning a bathtub, which comprises a step of simultaneously performing the heat recovery operation and the cleaning operation.

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