JP6927066B2 - Hot water storage type hot water supply device - Google Patents

Description

The present invention relates to a hot water storage type hot water supply device.

A hot water supply device capable of performing a bathtub heat recovery operation for recovering the heat of bath water remaining in the bathtub into a hot water storage tank is known (see, for example, Patent Document 1). Patent Document 1 has the following description. In the operation of heating and storing the water in the hot water storage tank (7) while collecting the residual hot water heat of the bathtub, when the residual hot water temperature at the outlet of the bath heat exchanger (10) drops to the first set temperature, the flow path switching means (13). ) Is switched to the discharge flow path (14) side, and the heat-exchanged low-temperature bath water is drained to the outside. The numbers in parentheses are the reference numerals in Patent Document 1.

Japanese Unexamined Patent Publication No. 11-337168

The device of Patent Document 1 has the following problems. When the heat-exchanged low-temperature bath water is drained to the outside, it is drained by operating the bath pump (17), so that the bath pump (17) consumes electric power. Therefore, it becomes difficult to improve energy saving.

The present invention has been made to solve the above-mentioned problems, and provides a hot water storage type hot water supply device capable of efficiently executing an operation of recovering the heat of bath water in a bathtub into a hot water storage tank with energy saving. The purpose is to do.

The hot water storage type hot water supply device according to the present invention includes a hot water storage tank, a heat exchanger that exchanges heat between bath water from a bathtub and tank water from a hot water storage tank, and a tank that circulates tank water to the heat exchanger. A tank water flow path having a water pump, a bath water circulation flow path having a bath water pump for circulating bath water to a heat exchanger, the operation of the tank water pump, the operation of the bath water pump, and installed at the bottom of the bathtub. It is equipped with a control means that can control the opening and closing of the automatic drain plug, and the control means includes a recovery operation that recovers the heat of the bath water in the bathtub into the hot water storage tank by operating the tank water pump and the bath water pump. It is possible to control the partial drainage operation of opening the automatic drain plug to drain a part of the bath water in the bathtub with the tank water pump and the bath water pump stopped, and at least the first recovery operation and the second recovery operation. It is a hot water storage type hot water supply device that can carry out two recovery operations, the first recovery operation, the partial drainage operation, and the second recovery operation in that order, and the control means continues the first recovery operation. The amount of bath water discharged in the partial drainage operation after the first recovery operation is adjusted based on the time and the circulating flow rate of the bath water during the first recovery operation .
Further, the hot water storage type hot water supply device according to the present invention circulates the heat exchanger that exchanges heat between the hot water storage tank, the bath water from the bathtub, and the tank water from the hot water storage tank, and the tank water to the heat exchanger. A tank water flow path having a tank water pump, a bath water circulation flow path having a bath water pump for circulating bath water to a heat exchanger, the operation of the tank water pump, the operation of the bath water pump, and installation at the bottom of the bathtub. The control means is provided with a control means capable of controlling the opening and closing of the automatic drain plug, and the control means is a recovery operation for recovering the heat of the bath water in the bathtub into the hot water storage tank by operating the tank water pump and the bath water pump. And, with the tank water pump and the bath water pump stopped, it is possible to control the automatic drain plug to open the automatic drain plug to drain a part of the bath water in the bath, and at least the first recovery operation and the first recovery operation. (Ii) A hot water storage type hot water supply device that can carry out two recovery operations, the first recovery operation, the partial drainage operation, and the second recovery operation, and is a bath to which a component having a purifying effect is added. It is further equipped with a cleaning device that can perform a pipe cleaning operation that allows water to flow through the bath water circulation flow path, and it is possible to alternately and repeatedly perform a recovery operation and a partial drainage operation. It is the lowest water level that can flow into the bath water circulation flow path, and the control means limits the number of partial drainage operations so that the water level in the bathtub before starting the pipe cleaning operation is higher than the circulatory water level, and pipes. After the washing operation is completed, the automatic drain plug is opened to drain all the bath water in the bathtub.

According to the present invention, it is possible to efficiently execute the operation of recovering the heat of the bath water in the bathtub to the hot water storage tank with energy saving.

It is a figure which shows the hot water storage type hot water supply apparatus by Embodiment 1. FIG. It is a circuit block diagram in the bath heat recovery mode in the hot water storage type hot water supply apparatus shown in FIG. It is a figure which shows the example of the temporal change of the bath return temperature in the bath heat recovery mode.

Hereinafter, embodiments will be described with reference to the drawings. Common or corresponding elements in the drawings are designated by the same reference numerals to simplify or omit duplicate description.

Embodiment 1.
FIG. 1 is a diagram showing a hot water storage type hot water supply device 35 according to the first embodiment. As shown in FIG. 1, the hot water storage type hot water supply device 35 of the first embodiment includes a tank unit 33, an HP (heat pump) unit 7, and a remote control device 44. The HP unit 7 and the tank unit 33 are connected to each other via an HP going pipe 14, an HP returning pipe 15, and an electric wiring (not shown). The control device 36 is built in the tank unit 33. The operation of various valves, pumps, etc. included in the tank unit 33 and the HP unit 7 is controlled by a control device 36 electrically connected to these.

The remote controller device 44 has a function of accepting an operation of the user regarding an operation operation command and a change of a set value. The remote control device 44 is an example of a user interface. The control device 36 and the remote control device 44 are connected by wire or wirelessly so that data communication is possible in both directions. Although not shown, the remote controller 44 is equipped with a display unit that displays information such as the state of the hot water storage type hot water supply device 35, an operation unit such as a switch operated by the user, a speaker, a microphone, and the like. The display unit of the remote controller device 44 has a function as a notification means for notifying the user of information. The remote control device 44 in the present embodiment may be provided with other notification means such as a voice guidance device.

In the present embodiment, the remote control device 44 may be installed on a wall such as a kitchen, a living room, or a bathroom. A plurality of remote control devices 44 may be able to communicate with the control device 36. Further, for example, a mobile terminal such as a smartphone may be configured to have a function as a user interface such as the remote control device 44. The mobile terminal and the control device 36 may communicate with each other via a network.

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 cyclically connected by a refrigerant pipe 5. The HP unit 7 operates the heat pump cycle by this refrigerant circuit. In the water refrigerant heat exchanger 3, water is heated by exchanging heat between the refrigerant compressed by the compressor 1 and the water guided from the tank unit 33. A configuration may be provided in which the refrigerant compressed by the compressor 1 and the water directly supplied from a water source such as tap water can be heat-exchanged by the water refrigerant heat exchanger 3.

The tank unit 33 contains the following various parts and pipes. The hot water storage tank 8 stores hot water. Inside the hot water storage tank 8, a temperature stratification can be formed in which the upper side is high temperature and the lower side is low temperature due to the difference in water density depending on the temperature. The hot water storage tank 8 is not limited to a single tank as shown in the figure, and may include a plurality of tanks connected in series. In a plurality of hot water storage tanks connected in series, the lower part of the upper tank and the upper part of the next tank on the lower side with respect to the tank are sequentially connected via a pipe. In the following description, the height direction, that is, the vertical position of the hot water storage tank 8 will be referred to. However, when the hot water storage tank 8 includes a plurality of tanks connected in series, the highest tank to the lowest tank 8 are provided. The vertical position shall be specified in the entire hierarchy up to the tank.

A third water supply pipe 9c is connected to the water introduction port 8a provided at the lower part of the hot water storage tank 8. The water supplied from a water source such as a water source through the first water supply pipe 9a is adjusted to a predetermined pressure by the pressure reducing valve 31 and then flows into the hot water storage tank 8 through the third water supply pipe 9c. At the upper part of the hot water storage tank 8, there are a hot water introduction outlet 8d for supplying the hot water stored in the hot water storage tank 8 to the outside of the hot water storage type hot water supply device 35, and a hot water introduction outlet 8e that can communicate with the HP return pipe 15. It is provided. A plurality of hot water storage temperature sensors 41, 42, and 43 are attached to the surface of the hot water storage tank 8 at different heights. The hot water storage temperature sensor 41 is located at the same height as the medium hot water introduction outlet 8f or at a height close to the medium hot water introduction outlet 8f. The hot water storage temperature sensor 42 is located higher than the hot water storage temperature sensor 41. The hot water storage temperature sensor 43 is located lower than the hot water storage temperature sensor 41. By detecting the temperature distribution of the hot water in the hot water storage tank 8 with these hot water storage temperature sensors 41, 42, 43, the amount of remaining hot water and the amount of heat storage in the hot water storage tank 8 can be calculated.

The control device 36 controls a boiling operation in which the hot water heated by the HP unit 7 flows into the hot water storage tank 8. The control device 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 water entry temperature sensor 40 attached to the HP going pipe 14 detects the water entry temperature, which is the temperature of the water flowing into the water refrigerant heat exchanger 3. The hot water temperature sensor 39 attached to the HP return pipe 15 detects the hot water temperature, which is the temperature of the hot water flowing out from the water refrigerant heat exchanger 3. In the boiling operation, it is as follows. The low-temperature water flowing out from the lower part of the hot water storage tank 8 is guided to the HP unit 7 via the HP going pipe 14, and is heated in the water-refrigerant heat exchanger 3 to become hot water, that is, high-temperature water. This high-temperature water flows into the hot water storage tank 8 from the hot water introduction outlet 8e at the upper part of the hot water storage tank 8 via the HP return pipe 15. By executing such a boiling operation, high-temperature water is stored from the upper layer inside the hot water storage tank 8, and the high-temperature water layer gradually becomes thicker. The control device 36 ends the boiling operation when the amount of hot water stored or the amount of heat stored in the hot water storage tank 8 grasped by the hot water storage temperature sensors 41, 42, 43 exceeds a predetermined amount.

The tank unit 33 includes a tank water pump 12 and a bath heat exchanger 20. The tank water pump 12 is a pump for circulating hot water in various pipes, and is provided on the first water supply pipe 13a. In the following description, the hot water stored in the hot water storage tank 8 may be referred to as "tank water". Further, the hot water stored in the bathtub 30 is referred to as "bath water". 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.

The bath going pipe 27 and the bath returning pipe 28 are connected to the bathtub adapter 80 installed on the inner wall of the bathtub 30. The bath heat exchanger 20 is installed in the middle of the bath going pipe 27 and the bath returning pipe 28. A bath going temperature sensor 37 for detecting the temperature of the bath water that has passed through the bath heat exchanger 20 is installed in the middle of the bath going pipe 27. In the middle of the bath return pipe 28, a bath water pump 29 for circulating bath water and a bath return temperature sensor for detecting the temperature of the bath water before exiting the bathtub 30 and entering the bath heat exchanger 20 38, a water level sensor 46 for detecting the water level in the bathtub 30, and a flow switch 47 for detecting the circulation of water in the bath return pipe 28 are installed. In the following description, the temperature detected by the bath return temperature sensor 38 is referred to as “bath return temperature”. Further, the temperature detected by the bath temperature sensor 37 is referred to as "bath temperature".

The three-way valve 11 is a flow path switching means having an inlet a port and a b port and an outlet c port. The three-way valve 11 is configured so that the flow path can be switched between the two paths ac and bc.

The four-way valve 16 is a flow path switching means having an inlet a port and a b port and an outlet c port and d port. The four-way valve 16 is configured so that the flow path can be switched between the four paths of ac, ad, bc, and bd.

The four-way valve 18 is a flow path switching means having an inlet a port and an outlet b port, c port, and d port. The four-way valve 18 is configured so that the flow path can be switched between the three paths of ab, ac, and ad.

The tank unit 33 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 the water outlet 8b provided at the lower part of the hot water storage tank 8 and the a port of the three-way valve 11. The first water supply pipe 13a connects the c port of the three-way valve 11 and the inlet of the tank water pump 12. The HP going pipe 14 connects the outlet of the tank water pump 12 and the inlet of the HP unit 7. The HP return pipe 15 connects the outlet of the HP unit 7 and the b port of the four-way valve 16. The first hot water pipe 17a connects the d port of the four-way valve 16 and 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 the water introduction port 8c provided at the lower part of the hot water storage tank 8. The third hot water pipe 19a connects the b port of the four-way valve 18 and the hot water introduction outlet 8e above the hot water storage tank 8. The fourth hot water pipe 19b connects the d port of the four-way valve 18 and the hot water introduction outlet 8d provided in the upper part of the hot water storage tank 8. The fifth hot water pipe 19c connects the c port of the four-way valve 18 and the hot water introduction port 8g provided between the upper part and the middle portion of the hot water storage tank 8.

The first tank circulation pipe 20a connects the b port of the four-way valve 18 and the inlet of the tank water of the bath heat exchanger 20. The second tank circulation pipe 20c connects the outlet of the tank water of the bath heat exchanger 20 and the b port of the three-way valve 11. The second water supply pipe 13b branches from between the tank water pump 12 and the inlet of the HP unit 7 in the HP going pipe 14, and is connected to the a port of the four-way valve 16.

Further, the tank unit 33 includes a medium temperature pipe 79, a first water supply pipe 9a, a second water supply pipe 9b, a third water supply pipe 9c, a fourth water supply pipe 9d, a hot water supply mixing valve 22, a bath mixing valve 23, and a medium temperature water switching. It has a valve 78, a hot water supply pipe 24, a bath pipe 25, a return pipe 20b, and a check valve 50.

The medium-temperature water switching valve 78 is a flow path switching means having an inlet a port and a b port and an outlet c port. The medium-temperature water switching valve 78 is configured so that the flow path can be switched between the two paths ac and bc.

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

One end of the first water supply pipe 9a is connected to a water source such as water services. The second water supply pipe 9b and the third water supply pipe 9c are connected to the other end of the first water supply pipe 9a via the pressure reducing valve 31. The second water supply pipe 9b is connected to the a port of the medium / hot water switching valve 78. The medium temperature pipe 79 connects the medium temperature water introduction outlet 8f provided in the middle portion of the hot water storage tank 8 and 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 obstructs the flow from the middle portion of the hot water storage tank 8 to the lower portion of the hot water storage tank 8. As a result, it is possible to reliably prevent the outflow of heat from the middle portion of the hot water storage tank 8 to the lower portion 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 / hot water switching valve 78. The other end of the fourth water supply pipe 9d is connected to the first inlet of each of the hot water supply mixing valve 22 and the bath mixing valve 23. One end of the high temperature pipe 21 communicates with the hot water introduction outlet 8d of the hot water storage tank 8. The other end of the high temperature pipe 21 is connected to the second inlet of each of the hot water supply mixing valve 22 and the bath mixing valve 23.

The medium temperature water switching valve 78 has two flows, 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. Use by switching the road condition. When the medium-temperature water switching valve 78 is set to the first flow path state, the low-temperature water supplied from the water source is supplied to the hot water supply mixing valve 22 and the bath mixing valve 23 through the second water supply pipe 9b and the fourth water supply pipe 9d. It will be in a state of being done. The first flow path state of the medium / hot water switching valve 78 corresponds to the “low temperature water usage state”. When the medium-temperature water switching valve 78 is placed in the second flow path state, the 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 to the hot water supply mixing valve 22 and the bath mixing valve. It will be in a state of being supplied to 23. The state of the second flow path of the medium-temperature water switching valve 78 corresponds to the “state of using medium-temperature water”.

The hot water supply mixing valve 22 is used by adjusting the flow rate ratio of the high temperature water supplied from the hot water storage tank 8 through the high temperature pipe 21 to the low temperature water or medium hot water supplied from the fourth water supply pipe 9d. Generates hot water at a set temperature set by the remote controller 44 and flows it into the hot water supply pipe 24. The hot water whose temperature has been adjusted by the hot water supply mixing valve 22 is supplied from the hot water supply pipe 24 to a faucet (not shown) such as a shower or a curan used by the user via a hot water tap 34.

The bath mixing valve 23 is used by adjusting the flow rate ratio of the high temperature water supplied from the hot water storage tank 8 through the high temperature pipe 21 to the low temperature water or medium hot water supplied from the fourth water supply pipe 9d. Can generate hot water at a set temperature set by the remote controller 44. The hot water adjusted to the set temperature by the bath mixing valve 23 flows into the bathtub 30 through the bath pipe 25 through the bath flow sensor 45, the bath electromagnetic valve 26, the bath going pipe 27, and the bath returning pipe 28.

The control device 36 determines the completion of hot water filling based on the information detected by the bath flow sensor 45 and the water level sensor 46, thereby determining the amount of hot water filling in the bathtub 30 when the hot water filling is completed. However, it can be controlled so as to be equal to the amount of hot water set by the user on the remote control device 44 (hereinafter, referred to as "set amount of hot water filling"). The hot water storage type hot water supply device 35 of the present embodiment may be capable of executing automatic bath operation. When the automatic bath operation is set by the remote control device 44, the control device 36 maintains the temperature and amount of the bath water in the bathtub 30 at the temperature and amount set by the remote control device 44 after the completion of hot water filling. As needed, the bath water is heated, cooled, added water, and squeezed water.

In the present embodiment, an automatic drain plug 81 that can be automatically opened and closed is installed at the bottom of the bathtub 30. When the automatic drain plug 81 is closed, bath water can be stored in the bathtub 30. When the automatic drain plug 81 is opened, the bath water in the bathtub 30 is discharged to, for example, a drain pipe (not shown) through the automatic drain plug 81. By opening the automatic drain plug 81, all the bath water in the bathtub 30 can be discharged to the outside. The automatic drain plug 81 opens and closes by being driven by, for example, an electric motor (not shown). The control device 36 can control the opening / closing operation of the automatic drain plug 81. The control device 36 may directly control the operation of the automatic drain plug 81, or the control device 36 sends a command to the control unit (not shown) of the automatic drain plug 81 installed in or near the bathroom. The control device 36 may indirectly control the operation of the automatic drain plug 81.

The remote control device 44 may be able to accept the user's operation for operating the automatic drain plug 81. In this case, the user can input a command for opening the automatic drain plug 81 and a command for closing the automatic drain plug 81 to the remote controller device 44. The user can remotely control the automatic drain plug 81 by operating the remote control device 44.

The control device 36 may send a command to close the automatic drain plug 81 at the start of the automatic bath operation. As a result, even if the user forgets to close the automatic drain plug 81 during hot water filling, the automatic drain plug 81 can be reliably closed and hot water can be stored in the bathtub 30.

The control device 36 in the present embodiment includes a bath heat recovery mode as a control mode. The bath heat recovery mode is a mode for recovering the heat of the bath water remaining in the bathtub 30 into the hot water storage tank 8 after the bathing is completed. FIG. 2 is a circuit configuration diagram of the hot water storage type hot water supply device 35 shown in FIG. 1 in the bath heat recovery mode. In the bath heat recovery mode, it is as follows. The three-way valve 11 is controlled so that the a port and the c port communicate with each other and the b port is closed. As a result, the low temperature pipe 10 and the first water supply pipe 13a communicate with each other, and the flow path to the second tank circulation pipe 20c is cut off. The four-way valve 16 is controlled so that the a port and the d port communicate with each other and the b port and the c port are closed. As a result, the second water supply pipe 13b and the first hot water pipe 17a communicate with each other, and the second hot water pipe 17b side is closed to block the flow path to the lower part of the hot water storage tank 8. The four-way valve 18 is controlled so that the a port and the b port communicate with each other and the c port and the d port are closed. As a result, the first hot water pipe 17a and the third hot water pipe 19a communicate with each other, and the fourth hot water pipe 19b and the fifth hot water pipe 19c side are closed to block the flow path to the intermediate portion of the hot water storage tank 8.

When starting the bath heat recovery mode, it may be controlled as follows. First, after the bath water circulation is started by starting the operation of the bath water pump 29, the tank water pump 12 is in a state where the three-way valve 11, the four-way valve 16, and the four-way valve 18 are controlled as described above. Operation is started. The tank water circulates as follows. The low-temperature tank water flowing out from the water outlet 8b of the hot water storage tank 8 through the low-temperature pipe 10 is the three-way valve 11, the first water supply pipe 13a, the tank water pump 12, the second water supply pipe 13b, the four-way valve 16, the first. It flows into the bath heat exchanger 20 through the 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 the temperature becomes close to the temperature of the bath water in the bathtub 30. This heated tank water may be hereinafter referred to as "heat recovery hot water". The heat recovery hot water flows from the bath heat exchanger 20 into the hot water storage tank 8 from the medium hot water introduction outlet 8f through the return pipe 20b, the check valve 50, and the medium temperature pipe 79. In the present embodiment, as described above, the flow path through which the tank water circulates corresponds to the “tank water flow path”. When the bath heat recovery mode is implemented, the heat recovery hot water is stored near the medium hot water introduction outlet 8f in the hot water storage tank 8.

When the bath water 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 going pipe 27 and flows into the bathtub 30 from the bathtub adapter 80. In the present embodiment, the flow path through which the bath water circulates corresponds to the "bath water circulation flow path" as described above.

In the present embodiment, the control device 36 performs a recovery operation and a partial drainage operation in the bath heat recovery mode. The recovery operation is an operation of transferring the heat of the bath water in the bathtub 30 into the hot water storage tank 8 by operating the tank water pump 12 and the bath water pump 29 at the same time. The partial drainage operation is an operation in which the automatic drain plug 81 is opened with the tank water pump 12 and the bath water pump 29 stopped, and a part of the bath water in the bathtub 30 is discharged to the outside.

The flow rate of bath water flowing through the bath going pipe 27 and the bath returning pipe 28 is hereinafter referred to as "bath water flow rate". The control device 36 can adjust the rotation speed of the bath water pump 29. The higher the rotation speed of the bath water pump 29, the higher the bath water flow rate. The bath water flow rate may be detected by a flow switch 47 or another flow rate sensor (not shown).

The control device 36 may start the bath heat recovery mode according to the operation of the user with respect to the remote control device 44. For example, the control device 36 may start the bath heat recovery mode when a predetermined button of the remote control device 44 is pressed.

If the temperature of the tank water in the lower part of the hot water storage tank 8 detected by the hot water storage temperature sensor 43 is lower than the bath return temperature detected by the bath return temperature sensor 38, the bath heat can be recovered. Therefore, the control device 36 may allow the start of the bath heat recovery mode when the detection temperature of the hot water storage temperature sensor 43 is lower than the bath return temperature.

When the recovery operation is performed, a temperature boundary layer is formed in the bath water in the bathtub 30. In the recovery operation, the bath water flowing out of the bath heat exchanger 20 is deprived of heat by the tank water and the temperature drops, so that the density becomes high. When this bath water flows into the bathtub 30, low-density, relatively high-temperature bath water stays above the bathtub 30, and high-density, relatively low-temperature bath water stays below the bathtub 30. In the bathtub 30, a temperature boundary layer having a high temperature on the upper side and a low temperature on the lower side is generated. If the temperature boundary layer is higher than the position of the bathtub adapter 80, the high temperature bath water on the upper layer side cannot be drawn into the bath return pipe 28, so that the temperature of the bath water flowing into the bath heat exchanger 20 is low. Therefore, the heat recovery efficiency is reduced. In the present embodiment, the position of the bathtub adapter 80 corresponds to the "bath water drawing position" that draws the bath water in the bathtub 30 into the bath water circulation flow path.

The control device 36 can carry out at least two recovery operations, a first recovery operation and a second recovery operation, in one bath heat recovery mode. Then, the control device 36 executes the first recovery operation, the partial drainage operation, and the second recovery operation in this order. As a result, the following effects can be obtained. When the first recovery operation is performed, as described above, a temperature boundary layer is generated in the bath water in the bathtub 30, so that the high temperature bath water on the upper layer side cannot be drawn into the bath return pipe 28, and heat exchange for the bath is performed. The temperature of the bath water flowing into the vessel 20 decreases. When a partial drainage operation is performed after the first recovery operation, the low-temperature bath water below the temperature boundary layer in the bathtub 30 is discharged from the automatic drain plug 81, and the position of the high-temperature bath water on the upper layer side moves downward. Moving. Therefore, if the second recovery operation is performed after the partial drainage operation, the high-temperature bath water can flow into the bath heat exchanger 20 through the bath return pipe 28, so that the heat recovery efficiency increases. In this way, according to the present embodiment, the amount of heat recovered to the hot water storage tank 8 can be sufficiently increased. Further, since the tank water pump 12 and the bath water pump 29 are stopped during the partial drainage operation, the tank water pump 12 and the bath water pump 29 do not consume electric power. Therefore, according to the present embodiment, it is possible to improve the heat recovery efficiency while suppressing the power consumption. Therefore, it is advantageous for improving energy saving.

The hot water storage type hot water supply device 35 of the present embodiment includes a bubble generator 48 installed in the bath water circulation flow path. In the present embodiment, in the bath water circulation flow path, the bubble generator 48 is located on the downstream side of the flow switch 47, and the bath heat exchanger 20 is located on the downstream side of the bubble generator 48.

The bubble generator 48 can generate bubbles in the bath water by mixing the air taken in from the outside with the bath water. The bubbles generated by the bubble generator 48 preferably include fine bubbles such as micro bubbles (for example, bubbles having a diameter of 50 μm or less). The bubble generator 48 may include, for example, the following ejectors. The ejector has a diameter-reduced portion that reduces the diameter of the bath water flow path. Air can be naturally aspirated by the negative pressure generated in this reduced diameter portion. At the reduced diameter portion, air is introduced from a direction perpendicular to the flow of bath water. A stationary blade that swivels the water flow flowing into the ejector may be provided at a position on the upstream side of the ejector. The stationary blade forms, for example, a swirling flow centered on the axis of the flow path. The swirling flow of bath water formed by the stationary blades shears the bubbles and makes them finer, so that fine bubbles can be generated.

The bubbles generated by the bubble generator 48, particularly fine bubbles, have a purifying effect of cleaning and removing stains such as sebum stains. In the present embodiment, the control device 36 can carry out the pipe cleaning operation. The pipe cleaning operation is an operation in which bath water containing air bubbles added by the air bubble generator 48 flows into the bath water circulation flow path. The bath water containing bubbles generated by the bubble generator 48 flows through the bath water circulation flow path, so that a cleaning effect of removing dirt adhering to the inner wall of the bath water circulation flow path can be obtained. In the present embodiment, the bubble generator 48 corresponds to a cleaning device capable of adding bubbles as a component having a purifying action to the bath water.

The bubbles generated by the bubble generator 48 are examples of components having a purifying effect. The component having a purifying action is not limited to air bubbles, and may be, for example, a detergent such as a surfactant, or a metal ion having an antibacterial effect (for example, silver ion, copper ion, etc.). In the pipe cleaning operation, a plurality of types of components having a purifying effect may be added to the bath water.

FIG. 3 is a diagram showing an example of a temporal change in the bath return temperature in the bath heat recovery mode. As shown in FIG. 3, during the execution of the first recovery operation and the second recovery operation, the bath return temperature decreases with the passage of time. This is because the bath water cooled by heat exchange with the tank water in the bath heat exchanger 20 flows into the bathtub 30 from the bath going pipe 27, so that the temperature of the bathtub in the bathtub 30 gradually decreases. To do. As described above, in the bathtub 30, due to the difference in the specific gravity of water due to the temperature difference, the comparison including the relatively high temperature upper layer bath water that has not yet exchanged heat and the bath water returned from the bath heat exchanger 20. A temperature boundary layer is formed between the bath water and the lower bath water at a relatively low temperature. During the first recovery operation and the second recovery operation, the temperature boundary layer in the bathtub 30 gradually moves upward. When the temperature boundary layer is above the bath water drawing position, the relatively low-temperature bath water once cooled flows into the bath heat exchanger 20 again, so that the heat recovery efficiency deteriorates.

As shown in FIG. 3, in the actual mode, by performing a partial drainage operation after the first recovery operation, the bath return temperature at the start of the second recovery operation is set at the end of the first recovery operation. It will be higher than the bath return temperature. Therefore, the temperature of the bath water flowing into the bath heat exchanger 20 can be raised, and the heat recovery efficiency is improved. In the example shown in FIG. 3, the bath return temperature at the start of the second recovery operation is substantially the same as the bath return temperature at the start of the first recovery operation.

The control device 36 may alternately and repeatedly perform the recovery operation and the partial drainage operation in one bath heat recovery mode. For example, it may be as follows. After the second recovery operation, the partial drainage operation may be performed again, and then the third recovery operation may be performed. Further, the partial drainage operation may be performed again after the third recovery operation, and then the fourth recovery operation may be performed. In this way, the control device 36 may perform the recovery operation three or more times in one bath heat recovery mode.

In the following description, the amount of bath water discharged by one partial drainage operation is referred to as "bath water discharge amount". The control device 36 may control the amount of bath water discharged. For example, the control device 36 can control the amount of bath water discharged by using the water level sensor 46. The control device 36 learns the relationship between the integrated flow rate detected by the bath flow rate sensor 45 and the bathtub water level detected by the water level sensor 46 when the bathtub is filled with hot water, so that the bathtub water level and the bathtub water in the bathtub 30 are learned. The relationship with the quantity can be memorized. Therefore, the control device 36 can control the amount of bath water discharged based on the amount of decrease in the bathtub water level detected by the water level sensor 46. Further, the control device 36 detects the rate of decrease in the bathtub water level [cm / min] when the automatic drain plug 81 is open with the water level sensor 46, so that the flow rate of bath water discharged from the automatic drain plug 81 [ L / min] can be learned. Therefore, the control device 36 can also control the bath water discharge amount by adjusting the time for continuing the partial drainage operation.

If the amount of bath water discharged is too large, the relatively high temperature bath water in the bathtub 30 will be discharged from the automatic drain plug 81, which is not preferable. On the contrary, if the amount of bath water discharged is too small, the layer of relatively high temperature bath water in the bathtub 30 does not come down to the bath water drawing position, so that the high temperature bath water cannot be supplied to the bath heat exchanger 20.

The control device 36 adjusts the bath water discharge amount in the partial drainage operation after the first recovery operation based on the time during which the first recovery operation continues and the bath water flow rate during the first recovery operation. May be good. As a result, it is possible to more reliably prevent excess or deficiency of the amount of bath water discharged. For example, the product of the bath water flow rate during the first recovery operation (for example, 3 L / min) and the duration of the first recovery operation (for example, 30 minutes) is the low temperature accumulated in the bathtub 30 during the first recovery operation. It can be considered to correspond to the amount of bath water (for example, 90 L). In this case, the control device 36 can more reliably prevent excess or deficiency of the bath water discharge amount by adjusting the bath water discharge amount with reference to 90 L calculated as the above product.

For example, when the flow rate of the bath water discharged from the automatic drain plug 81 is 10 L / min, in order to set the bath water discharge amount to 90 L, the control device 36 has a duration of a partial drainage operation of 9 minutes. It may be controlled as follows.

When the recovery operation and the partial drainage operation are alternately and repeatedly performed, the control device 36 may control the bath water discharge amount in the second and subsequent partial drainage operations in the same manner as described above. ..

Further, the control device 36 may be adjusted so that the bath water discharge amount is equal to or less than a predetermined upper limit drainage amount. For example, the control device 36 may set the upper limit drainage amount to 1/2 of the total amount of bath water in the bathtub 30 before the partial drainage operation, and adjust the bath water discharge amount to be equal to or less than the upper limit drainage amount. For example, the control device 36 sets 1/2 of the set hot water filling amount (for example, 180 L) as the upper limit drainage amount (for example, 90 L) of the partial drainage operation after the first recovery operation, and discharges the bath water of the partial drainage operation. The amount may be adjusted so as to be equal to or less than the upper limit drainage amount. By doing so, it is possible to prevent excess or deficiency of the amount of bath water discharged by a simpler treatment.

The flow switch 47 corresponds to a flow detecting means for detecting the presence or absence of a flow of bath water in the bath water circulation flow path. There is a lower limit to the flow rate at which the flow switch 47 can detect the flow. Here, it is assumed that the lower limit flow rate at which the flow switch 47 can detect the flow is 3 L / min. In this case, if the bath water pump 29 is operated at a rotation speed such that the bath water flow rate is lower than the lower limit flow rate of 3 L / min, the flow switch 47 confirms whether the bath water is circulating normally. It is not preferable because it cannot be done. From the above viewpoint, the control device 36 rotates so that the rotation speed of the bath water pump 29 in the recovery operation is the lower limit rotation speed at which the flow switch 47 can detect the flow, that is, the bath water flow rate becomes the lower limit flow rate. It is desirable to control it so that it is equal to the speed. This makes it possible to reliably confirm the bath water circulation by the flow switch 47, and further improve the heat exchange capacity of the bath heat exchanger 20.

If the bath return temperature decreases with the passage of time during the execution of the first recovery operation, the temperature difference between the bath water and the tank water inside the bath heat exchanger 20 decreases, so heat exchange occurs. The amount will be low. As a result, the difference between the temperature of the bath water coming out of the bathtub 30 and the temperature of the bath water returning to the bathtub 30 becomes small, so that the amount of change in the bath return temperature per hour becomes small. The position indicated by the arrow A in FIG. 3 corresponds to the case where the amount of change in the bath return temperature per hour is reduced in this way.

When the amount of change in the bath return temperature per hour detected by the bath return temperature sensor 38 becomes smaller than the reference during the execution of the first recovery operation, the control device 36 ends the first recovery operation and partially drains water. The process of shifting to the operation may be performed. It is considered that the decrease in the amount of change in the bath return temperature per hour means a decrease in the amount of heat exchange in the bath heat exchanger 20, that is, a decrease in heat recovery efficiency. For this reason, when the amount of change in the bath return temperature per hour becomes smaller than the standard, the first recovery operation is terminated and the partial drainage operation is performed, so that the partial drainage operation is performed at an appropriate timing. The heat recovery efficiency can be restored by discharging the low-temperature bath water accumulated in the lower layer in the bathtub 30 and lowering the high-temperature bath water layer below the bath water drawing position. In addition, since the transition from the first recovery operation to the partial drainage operation is determined based on the amount of change in the bath return temperature per hour, it is not affected by the temporary fluctuation of the bath return temperature due to the disturbance. Therefore, it is possible to reliably prevent the first recovery operation from being terminated at an inappropriate timing.

In the above process, the control device 36 may be, for example, as follows. When the difference between the maximum value and the minimum value of the detected values of the plurality of bath return temperatures detected during the predetermined time (for example, 15 seconds) is equal to or less than the reference value (for example, 1 ° C.), the bath return is performed. It may be considered that the amount of change in temperature per hour is smaller than the standard.

The control device 36 may also control the timing of shifting to the partial drainage operation in the same manner as described above during the second recovery operation or the third and subsequent recovery operations.

When the continuous time of the first recovery operation exceeds a preset upper limit time, the control device 36 may end the first recovery operation and shift to a partial drainage operation. The upper limit time is, for example, one hour. When the upper limit time elapses from the start of the first recovery operation, relatively low temperature bath water accumulates above the bath water drawing position, and the amount of heat that can be recovered is small even if the first recovery operation is continued, resulting in reduced efficiency. It is thought that. Therefore, when the upper limit time has passed, it is desirable to shift to a partial drainage operation. Further, while the heat of the bath water below the temperature boundary layer in the bathtub 30 is being recovered for a long time, the heat of the bath water above the temperature boundary layer is dissipated, and the amount of heat that can be recovered as a whole decreases. there's a possibility that. From this point of view as well, setting an upper limit time for the continuous time of the first recovery operation is advantageous in preventing a decrease in recovery efficiency. By setting the upper limit time for the first recovery operation, the first recovery operation can be completed at an appropriate timing even when the amount of change in the bath return temperature per hour does not satisfy the above-mentioned conditions.

The control device 36 may also set the upper limit time in the same manner as described above during the second recovery operation or the third and subsequent recovery operations.

The control device 36 may end the execution of the bath heat recovery mode when the bath return temperature rises during the execution of the recovery operation. When the bath return temperature becomes lower than the temperature of the tank water flowing into the bath heat exchanger 20 in the recovery operation, the bath water heated by the tank water flows into the bathtub 30, and the bath water returns to the bath temperature sensor 38. The temperature at which the bath returns to the bath rises. Therefore, when the bath return temperature rises, it is considered that the temperature of the bath water in the bathtub 30 is lower than the temperature of the tank water flowing into the bath heat exchanger 20, so that the bath heat recovery mode is executed. Can be determined to be terminated.

The control device 36 may automatically perform the pipe cleaning operation after the bath heat recovery mode ends. Further, the control device 36 may open the automatic drain plug 81 after the completion of the pipe cleaning operation to drain all the bath water in the bathtub 30. As a result, the user does not have to perform the operation of draining the inside of the bathtub 30, so that the usability is improved.

In the following description, the lowest water level at which the bath water in the bathtub 30 can flow into the bath water circulation flow path is referred to as a “circulatory water level”. The circulatory water level is, for example, a water level at which the water surface in the bathtub 30 is slightly higher than the bath water drawing position.

When the recovery operation and the partial drainage operation are alternately and repeatedly performed in the bath heat recovery mode, the control device 36 sets the water level in the bathtub 30 before starting the pipe cleaning operation to be equal to or higher than the circulatory water level. The number of partial drainage operations may be limited. As a result, it is possible to more reliably prevent the occurrence of an event in which the bathtub water level becomes lower than the circulatory water level before the start of the pipe cleaning operation and the pipe cleaning operation cannot be performed. In this case, the control device 36 may be as follows, for example. The control device 36 sets the number of possible partial drainage operations based on the relationship between the set amount of hot water filling and the amount of bath water discharged set at the end of the first recovery operation. For example, assuming that the set amount of hot water is 240 L, the amount of bath water in the bathtub 30 is 90 L when the water level can be circulated, and the amount of water discharged at one time is 60 L, the bath in the bathtub 30 is used for the first partial drainage operation. The amount of water decreased from 240L to 180L, the amount of bath water in the bathtub 30 decreased from 180L to 120L in the second partial drainage operation, and the amount of bath water in the bathtub 30 decreased from 120L to 60L in the third partial drainage operation. It can be predicted to decrease. Therefore, when the third partial drainage operation is performed, the water level falls below 90 L, which corresponds to the circulatory water level, so that the number of partial drainage operations that can be performed is up to two. That is, in this example, the control device 36 limits the number of partial drainage operations to two. In this example, the control device 36 performs the third recovery operation after the second partial drainage operation, performs the pipe cleaning operation after the third recovery operation, and after the completion of the pipe cleaning operation, the automatic drain plug 81. May be opened to drain all the bath water in the bathtub 30.

While the bath heat recovery mode is being executed, the user may be notified that the bath heat recovery mode is being executed by at least one of the display unit of the remote controller device 44 and the voice guidance device. As a result, when the bath heat recovery mode is automatically operated, it is possible to prevent the user from misunderstanding that it is a malfunction. Further, the user may be notified by at least one of the display unit of the remote controller device 44 and the voice guidance device whether the recovery operation or the partial drainage operation is being executed. For example, the characters "heat recovery in progress" may be displayed during the recovery operation, and the characters "automatic drainage in progress" may be displayed during the partial drainage operation. As a result, even when the automatic drain plug 81 is opened during the execution of the bath heat recovery mode, the user can confirm that the device is not abnormal, and the usability is improved.

1 Compressor, 3 Water refrigerant heat exchanger, 4 Expansion valve, 5 Coolant piping, 6 Air heat exchanger, 7 HP unit, 8 Hot water storage tank, 8a Water inlet, 8b Water outlet, 8c Water inlet, 8d, 8e hot water inlet, 8f medium hot water inlet, 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 tank Water pump, 13a 1st water supply pipe, 13b 2nd water supply pipe, 16 4-way valve, 17a 1st hot water pipe, 17b 2nd hot water pipe, 18 4-way valve, 19a 3rd hot water pipe, 19b 4th hot water pipe, 19c 5th Hot water piping, 20 Bath heat exchanger, 20a 1st tank circulation piping, 20b Return piping, 20c 2nd tank circulation piping, 21 High temperature piping, 22 Hot water supply mixing valve, 23 Bath mixing valve, 24 Hot water supply piping, 25 Bath Piping, 26 Bath electromagnetic valve, 29 Bath water pump, 30 Bathtub, 31 Pressure reducing valve, 33 Tank unit, 34 Hot water tap, 35 Hot water storage type hot water supply device, 36 Control device, 37 Bath going temperature sensor, 38 Bath return temperature sensor, 41, 42, 43 Hot water storage temperature sensor, 44 remote control device, 45 bath flow sensor, 46 water level sensor, 47 flow switch, 48 bubble generator, 50 check valve, 78 medium temperature water switching valve, 79 medium temperature piping, 80 bath adapter , 81 Automatic drain plug

Claims (8)

Hot water storage tank and
A heat exchanger that exchanges heat between the bath water from the bathtub and the tank water from the hot water storage tank.
A tank water flow path having a tank water pump that circulates the tank water to the heat exchanger, and
A bath water circulation flow path having a bath water pump for circulating the bath water to the heat exchanger,
A control means capable of controlling the operation of the tank water pump, the operation of the bath water pump, and the opening / closing of the automatic drain plug installed at the bottom of the bathtub is provided.
The control means includes a recovery operation for recovering the heat of the bath water in the bathtub into the hot water storage tank by operating the tank water pump and the bath water pump, and the tank water pump and the bath water pump. It is possible to control the partial drainage operation of opening the automatic drain plug in the stopped state and discharging a part of the bath water in the bathtub.
At least two recovery operations, a first recovery operation and a second recovery operation, can be performed.
A hot water storage type hot water supply device that performs the first recovery operation, the partial drainage operation, and the second recovery operation in this order.
The control means discharges in the partial drainage operation after the first recovery operation based on the time during which the first recovery operation continues and the circulation flow rate of the bath water during the first recovery operation. A hot water storage type hot water supply device that adjusts the amount of the bath water. Hot water storage tank and
A heat exchanger that exchanges heat between the bath water from the bathtub and the tank water from the hot water storage tank.
A tank water flow path having a tank water pump that circulates the tank water to the heat exchanger, and
A bath water circulation flow path having a bath water pump for circulating the bath water to the heat exchanger,
A control means capable of controlling the operation of the tank water pump, the operation of the bath water pump, and the opening / closing of the automatic drain plug installed at the bottom of the bathtub is provided.
The control means includes a recovery operation for recovering the heat of the bath water in the bathtub into the hot water storage tank by operating the tank water pump and the bath water pump, and the tank water pump and the bath water pump. It is possible to control the partial drainage operation of opening the automatic drain plug in the stopped state and discharging a part of the bath water in the bathtub.
At least two recovery operations, a first recovery operation and a second recovery operation, can be performed.
A hot water storage type hot water supply device that performs the first recovery operation, the partial drainage operation, and the second recovery operation in this order.
Further provided with a cleaning device capable of performing a pipe cleaning operation for flowing the bath water to which a component having a purifying action is added to the bath water circulation flow path.
The recovery operation and the partial drainage operation can be alternately repeated.
The circulatory water level is the lowest water level at which the bath water in the bathtub can flow into the bath water circulation flow path.
The control means limits the number of times of the partial drainage operation so that the water level in the bathtub becomes equal to or higher than the circulatory water level before starting the pipe cleaning operation, and after the pipe cleaning operation is completed, the automatic operation. A hot water storage type hot water supply device that opens a drain plug and discharges all the bath water in the bathtub. A temperature detecting means for detecting the temperature of the bath water flowing from the bathtub into the heat exchanger is provided.
When the amount of change in the bath water temperature per hour detected by the temperature detecting means becomes smaller than the reference during the execution of the first recovery operation, the control means terminates the first recovery operation and performs the partial recovery operation. The hot water storage type hot water supply device according to claim 1 or 2, which shifts to a drainage operation. The control means any one of claims 1 to 3 which terminates the first recovery operation and shifts to the partial drainage operation when the time during which the first recovery operation continues exceeds the upper limit time. Hot water storage type hot water supply device described in. The hot water storage type hot water supply device according to any one of claims 1 to 4, wherein the control means adjusts the amount of the bath water discharged in the partial drainage operation so as to be equal to or less than the upper limit drainage amount. A water level detecting means for detecting the water level in the bathtub is provided.
The control means according to claim 1 to 5, wherein the control means adjusts the discharge amount of the bath water in the partial drainage operation or the time for continuing the partial drainage operation based on the detection value of the water level detecting means. The hot water storage type hot water supply device according to any one item. A temperature detecting means for detecting the temperature of the bath water flowing from the bathtub into the heat exchanger is provided.
The control means according to any one of claims 1 to 6 , wherein when the bath water temperature detected by the temperature detecting means rises during the execution of the recovery operation, the control means ends the execution of the recovery operation. Hot water storage type hot water supply device. The hot water storage type hot water supply device according to any one of claims 1 to 7 , further comprising a notification means for notifying the fact that the recovery operation or the partial drainage operation is being executed.

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