JP7759864B2 - Bath equipment with electric drain valve - Google Patents

Description

The present invention relates to anti-freeze operation for bath equipment equipped with an electric drain valve.

It has been known that in bathtub systems equipped with this type of electric drain valve, the electric drain valve can automatically close when filling the bathtub, or the user can manually operate a control switch on a remote control to drain the bathtub water when bathing is finished (Patent Document 1).

In addition, during seasons when the outside temperature is low and bath operations such as filling the bath or reheating the water are not being performed, the water in the bath circulation circuit connected to the bathtub freezes, so an anti-freeze operation is performed to circulate bathwater between the bathtub and the bath circulation circuit (Patent Document 2).

It is also known that when the outside temperature drops to a point where the pipes may freeze, the electric drain valve is closed, the bathtub is filled with hot water, and the water accumulated in the bathtub is circulated through the bath circulation circuit to prevent the bath circulation circuit from freezing (Patent Document 3).

JP 2017-198379 A Japanese Patent Application Publication No. 11-325597 JP 2014-95518 A

However, with this conventional system, the decision to start anti-freeze operation and the filling operation are carried out based on the value detected by the outside air temperature sensor, so there is a problem that if there are young children or pets in the bathtub, or if the bathtub is being used for purposes other than bathing, the filling operation may be carried out at an unexpected and sudden time.

In order to solve the above problem, claim 1 of the present invention provides a bathtub in a bathroom, an electric drain valve that can be electrically opened and closed to drain the bathtub water from the bathtub, a bath circulation circuit connected to the bathtub and circulating the bathtub water using a bath circulation pump, a filling circuit that fills the bathtub with hot water, a remote control that can issue instructions for various operations and can notify the user to perform specific operations, an outside air temperature sensor that detects the outside air temperature, a filling operation that fills the bathtub with the desired amount of hot water from the filling circuit, and a freeze prevention operation that circulates the bathtub water between the bathtub and the bath circulation circuit for a predetermined period of time to prevent the bath circulation circuit from freezing. In a bathtub device with an electric drain plug that performs the above-mentioned function and that is equipped with a control device communicably connected to the remote control, when the remote control is used to start draining the water using the electric drain plug, the control device notifies the remote control, allowing the user to choose whether or not to perform the predetermined amount of water filling operation. If the user selects to perform the water filling operation using the remote control, after draining the water, if the detected value of the outside air temperature sensor is below a predetermined temperature, the control device performs the predetermined amount of water filling operation. After the predetermined amount of water filling operation is completed, if the detected value of the outside air temperature sensor is below a predetermined temperature, which is the predetermined temperature at which anti-freeze operation starts, the control device performs the anti-freeze operation.

Furthermore, in claim 2, when the filling operation is selected using the remote control, if the detected value of the outside air temperature sensor is higher than the predetermined temperature after the drainage is completed, the control device does not perform the selected filling operation, and when the detected value of the outside air temperature sensor falls below the predetermined temperature, the control device performs the filling operation for the predetermined amount.

In addition, according to claim 3, when the remote control is used to start draining the water using the electric drain valve, the control device issues a notification that allows the user to choose whether or not to perform the predetermined amount of water filling operation if the detected value of the outside air temperature sensor is equal to or lower than a predetermined predicted freezing temperature that is higher than the predetermined temperature.

This invention allows users to select in advance whether or not to fill the bathtub with a specified amount of water after draining. This prevents the bathtub from being filled with a specified amount of water at unexpected times when the outside temperature drops, when there are young children or pets in the bathtub, or when the bathtub is being used for purposes other than bathing. It also reliably prevents the bathtub circulation circuit from freezing based on the planned use of the bathtub.

Schematic diagram of an embodiment of the present invention A flowchart illustrating the antifreeze operation of the same embodiment. Table for bath circulation pump ON/OFF control A flowchart illustrating the antifreeze operation after drainage is completed in the same embodiment.

Next, one embodiment of the present invention will be described with reference to the drawings. 1 is a hot water storage tank that stores hot water, 2 is a heat pump unit that is an outdoor unit installed outdoors as a heating means for heating the hot water, and 3 is a bathtub.

Reference numeral 4 denotes a heating circulation circuit that connects the hot water storage tank 1 and the heat pump unit 2 in a circulatory manner. It has a heating circulation pump 5 and is composed of a heat pump supply pipe 4a connected to the bottom of the hot water storage tank 1 and a heat pump return pipe 4b connected to the top of the hot water storage tank 1. Cold water at the bottom of the hot water storage tank 1 is heated by the heat pump unit 2 via the heat pump supply pipe 4a, and the heated high-temperature hot water is returned to the top of the hot water storage tank 1 via the heat pump return pipe 4b, heating and storing the hot water in the hot water storage tank 1. The outer surface of the hot water storage tank 1 is also vertically fitted with multiple hot water temperature sensors 6a, 6b, 6c, and 6d, which detect the amount of hot water stored by detecting a temperature above a predetermined hot water temperature.

7 is a water supply pipe that supplies water to the hot water storage tank 1, 8 is a hot water outlet pipe that dispenses hot water from the hot water storage tank 1, 9 is a mixing valve that mixes cold water from the water supply pipe 7 and hot water from the hot water outlet pipe 8 to reach the set temperature, 10 is a hot water supply pipe that supplies the mixed hot water at the set temperature, and 11 is a faucet installed at the end of the hot water supply pipe 10. 12 is a hot water supply temperature sensor installed downstream of the mixing valve 9, and 13 is a hot water supply flow rate sensor that counts the amount of hot water supplied. 14 is a pressure reducing valve that reduces the water pressure to a specified pressure, and 15 is a pressure relief valve that releases overpressure caused by heating.

16 is a bath circulation circuit that connects an indirect heat exchanger 17 consisting of a coiled pipe installed inside the hot water storage tank 1 to the bathtub 3 via a bath supply pipe 16a and a bath return pipe 16b to enable circulation. 18 is a bath circulation pump installed in the bath circulation circuit 16, 19 is a water flow sensor that detects the presence or absence of running water, 20 is a bath temperature sensor that detects the temperature of the bathtub water flowing through the bath circulation circuit 16, and 21 is a water level sensor that detects the water level in the bathtub 3 from the water pressure of the bathtub water.

Here, the water level sensor 21 is installed within the bath circulation circuit 16, and in order to detect the water pressure of the bathtub water, the water level must be above the bathtub circulation port (not shown) in order for the bathtub water to circulate within the bathtub circulation circuit. Therefore, if the water level is below the circulation port, it is determined that there is no water in the bathtub even if there is water in the bathtub, and if the water level is above the circulation port, it is determined that there is water in the bathtub.

22 is a bypass pipe that bypasses the indirect heat exchanger 17 and connects the bath supply pipe 16a and the bath return pipe 16b. A flow path switching means 23 consisting of a three-way valve is provided at the connection between the bypass pipe 22 and the bath return pipe 16b, and selectively switches whether or not the hot water flowing through the bath circulation circuit 16 flows through the indirect heat exchanger 17.

24 is a filling pipe that branches off from the hot water supply pipe 10 and is connected to the bath circulation circuit 16 to fill the bathtub 3 with hot water. 25 is a filling valve installed on this filling pipe 24 that starts and stops filling the bathtub 3 with hot water. 26 is a bath flow sensor that counts the amount of hot water filled into the bathtub 3. 27 is a two-way valve installed between the filling pipe 24 and the water level sensor 21. When filling the bathtub, it opens once to air purge the piping from the filling pipe 24 of the bath return pipe 16b to the bathtub 3, and then closes to allow the water level sensor 21 to monitor the exact water level while filling the bathtub 3.

28 is a heating control unit that controls the heating of the heat pump unit 2, and 29 is a control device that controls the boiling operation, hot water supply, and bath. The control device 29 is equipped with a freeze prevention operation control means 30 that controls the freeze prevention operation described below, and the heat pump unit 2 is equipped with an outdoor air temperature sensor 31 that detects the outdoor air temperature.

32 is a remote control installed inside or outside the bathroom. The remote control 32 is equipped with a display unit 33, which is a notification means that displays various information on a screen, an operation unit 34 that issues various operational instructions to the control device 29 and allows the user to operate the device in accordance with the displayed information, and a speaker 35, which is a notification means that notifies various information by sound, and is connected to the control device 29 so that they can communicate with each other.

36 is an electric drain valve that can be remotely opened and closed by the user operating the remote control 32, which sends an electrical signal from the control device 29 to the electric drain valve 36.

Next, the operation of this hot water storage type bath water heater will be explained below.
First, let us explain the heating operation, in which the heat pump unit 2 heats the hot water stored in the hot water storage tank 1. When the hot water storage temperature sensors 6a-d detect that the required amount of heat for the next day is not remaining in the hot water storage tank 1 during the late-night power period, when the unit price of electricity under the time-of-day contracted power is low, the control device 29 instructs the heating control unit 28 to start the heating operation. Upon receiving the instruction, the heating control unit 28 starts operating the compressor (not shown) and the heating circulation pump 5. The cold water supplied from the bottom of the hot water storage tank 1 via the heating circulation circuit 4 is heated to a high temperature in a water-refrigerant heat exchanger (not shown), and the water is returned to the top of the hot water storage tank 1. The hot water is then stacked sequentially from the top of the hot water storage tank 1 to store the hot water. When the hot water storage temperature sensors 6a-d detect that the required amount of heat has been stored in the hot water storage tank 1, the control device 29 instructs the heating control unit 28 to stop the heating operation. Upon receiving the instruction, the heating control unit 28 stops operating the compressor and the heating circulation pump 5, thereby terminating the heating operation.

When the faucet 11 is opened, the control device 29 adjusts the opening of the mixing valve 9 so that the cold water from the water supply pipe 7 and the hot water from the hot water outlet pipe 8 are mixed together to provide hot water at the set temperature set by the remote control 32 connected to the control device 29.

Next, when a command to fill the bath is issued via the remote control 32, the control device 29 opens the filling valve 25, and the cold water from the water supply pipe 7 and the hot water from the hot water outlet pipe 8 are adjusted by the mixing valve 9 to the bath temperature set via the remote control 32. The water is then filled to the bathtub 3 via the filling pipe 24 and the bath circulation circuit 16 until the bath flow sensor 26 counts the preset amount. At this time, the flow path switching means 23 installed in the bypass pipe 22 switches to the bypass pipe 22 side, and the hot water adjusted to the set temperature and flowing into the bath circulation circuit 16 during filling flows through the bypass pipe 22. Therefore, the hot water adjusted to the set temperature by the mixing valve 9 does not flow through the indirect heat exchanger 17 in the hot water storage tank 1, which stores hot water at a higher temperature, and is not heated above the set temperature by the indirect heat exchanger 17.

In addition, when a command to reheat the bath is issued via remote control 32, control device 29 switches flow path switching means 23 to the indirect heat exchanger 17 side and drives bath circulation pump 18, causing the hot water in bathtub 3 to circulate through indirect heat exchanger 17, which is installed in the high-temperature hot water in hot water storage tank 1, and heating the bathwater using the heat of the hot water stored in hot water storage tank 1. Because the hot water in hot water storage tank 1 can be used to reheat or keep warm the hot water in bathtub 3, an electric heater dedicated to reheating or keeping warm is not required, thereby reducing costs and power consumption.

During daytime hours, when the amount of hot water in the hot water storage tank 1 decreases due to hot water supply or filling, and the hot water storage temperature sensors 6a-6d detect a lack of the required heat, the control device 29 instructs the heating control unit 28 to start reheating operation. Upon receiving the instruction, the heating control unit 28 starts operating the compressor and heating circulation pump 5, and the cold water supplied from the bottom of the hot water storage tank 1 via the heating circulation circuit 4 is heated to a high temperature in the water-refrigerant heat exchanger, returned to the top of the hot water storage tank 1, and the high-temperature water is stored in layers starting from the top of the hot water storage tank 1. Then, when the hot water storage temperature sensors 6a-d detect that the required amount of heat has been stored in the hot water storage tank 1, the control device 29 instructs the heating control unit 28 to stop reheating operation. Upon receiving the instruction, the heating control unit 28 stops operating the compressor and heating circulation pump 5, thereby ending reheating operation. Note that reheating operation is not performed if the setting prohibits reheating during daytime hours.

Next, the anti-freeze operation when there is a risk of the bath water in the bath circulation circuit 16 freezing in winter or the like will be described with reference to the flowchart shown in FIG.
When the outdoor air temperature sensor 31 of the heat pump unit 2 detects a temperature below the predetermined antifreeze start temperature (here, 2°C) at which antifreeze operation starts (Yes in step S1) while bath operations such as filling the water or reheating the water are not being performed, the antifreeze operation control means 30 switches the flow path switching means 23 to the bypass pipe 22 (step S2) and drives the bath circulation pump 18 (step S3). Note that in this embodiment, the start of antifreeze operation is determined based on the outdoor air temperature detected by the outdoor air temperature sensor 31, but the start of antifreeze operation may also be determined based on the bathtub water temperature detected by the bath temperature sensor 20 or the temperature detected by an internal temperature sensor (not shown). Any temperature sensor capable of detecting the risk of freezing will suffice.

The anti-freeze operation control means 30 then determines whether the water flow sensor 19 is on (step S4). If it is on, it determines that there is a circulatable amount of bathtub water remaining in the bathtub 3 (step S5). If it is off, it determines that there is no bathtub water in the bathtub 3 (step S9). At this time, if the control device 29 has a history of performing a predetermined amount of water filling operation, which is the amount of water required to bring the water level higher than the circulation port of the bathtub 3, and there is no history of the electric drain valve 36 being opened thereafter, it may omit the water level confirmation step.

If it is determined in step S5 that there is bathwater in the bathtub 3, the anti-freeze operation control means 30 refers to the ON/OFF control in the table in Figure 4, activates and deactivates the device at times according to the outside air temperature, and begins anti-freeze operation (step S6).

Then, according to the table in Figure 4, the bath circulation pump 18 is driven for the ON time (S7) and stopped for the OFF time (S8).

Also, if it is determined in step S9 that there is no bathtub water in the bathtub 3, the anti-freeze operation control means 30 refers to the ON/OFF control in the table in Figure 4, activates and deactivates the device at times according to the outside air temperature, and begins anti-freeze operation (step S10).

Next, the anti-freezing operation when the water in the bathtub 3 is drained using the electric drain valve 36 will be described in detail with reference to the flowchart of FIG.
First, when the remote control 32 is used to instruct the electric drain valve 36 to be opened (S11: Yes), the anti-freeze operation control means 30 compares the outside air temperature detected by the outside air temperature sensor 31 with a predetermined predicted freezing temperature (here, for example, 7°C), which is the temperature at which the possibility of the water in the bath circulation circuit 16 freezing in the future is determined (S12).

If the outside air temperature is below the predetermined predicted freezing temperature (Yes in S12), the anti-freeze operation control means 30 determines that there is a possibility that the water in the bath circulation circuit 16 will freeze in the future, and issues a notification from the notification means of the remote control 32 saying, "The outside air temperature is low, and there is a possibility that the pipes will freeze. Would it be okay to perform a specified amount of water filling operation during anti-freeze operation?", and displays an option to select "Allow" or "Not Allow" for the specified amount of water filling operation (S13). At this time, the user can use the operation means 34 to select from the options displayed on the display unit 33 of the remote control 32.

Then, after drainage is completed (Yes in S14), the anti-freeze operation control means 30 checks whether filling with water to the specified amount is permitted in S13 (S15).

When the predetermined amount of water filling operation is permitted (S15: Yes) and the outside air temperature detected by the outside air temperature sensor 31 falls below a predetermined temperature (e.g., 3°C) that determines whether preparations for anti-freeze operation should begin (S16: Yes), the predetermined amount of water filling operation, which is the amount of water needed to bring the water level higher than the circulation port of the bathtub 3, is started (S18: Yes).

Then, after the predetermined amount of water filling operation has been completed, the anti-freeze operation control means 30 checks whether the outside air temperature detected by the outside air temperature sensor 31 is below the predetermined anti-freeze operation start temperature (here, below 2°C), which is the temperature that determines the start of anti-freeze operation (S19), and starts anti-freeze operation 1 according to the table shown in Figure 3 (S21). After that, it turns the bath circulation pump 18 on and off according to the table shown in Figure 3, ends the anti-freeze operation (Yes in S21), returns to S19, and repeats from there. This repeated control may be reset, for example, at the daily changeover time at midnight, when the water filling operation is performed for bathing, or when the electric drain valve 36 is switched to the open state.

In this way, by being able to select in advance whether to "allow" or "disallow" the specified amount of water filling operation after draining has finished, it is possible to prevent the specified amount of water filling operation from being started unexpectedly when the outside temperature drops, when there are young children or pets in the bathtub 3, or when the bathtub 3 is being used for purposes other than bathing, and the user can reliably prevent the bath circulation circuit 16 from freezing by scheduling the use of the bathtub 3.

Furthermore, if the outside air temperature is higher than the predetermined predicted freezing temperature in S12 (S12 is No), the anti-freeze operation control means 30 determines that it is a season in which anti-freeze operation is unlikely to be performed.

However, if the outside air temperature drops over time to a temperature where there is a risk of freezing, anti-freeze operation must be performed. Therefore, the anti-freeze operation control means 30 continues to detect the outside air temperature using the outside air temperature sensor 31, and if the outside air temperature detected by the outside air temperature sensor 31 falls below the predetermined anti-freeze operation start temperature (Yes in S22), it starts anti-freeze operation 2 according to the table shown in Figure 3 (S23). After that, it turns the bath circulation pump 18 on and off according to the table shown in Figure 3, and then ends anti-freeze operation (Yes in S24), returns to S22, and repeats the process.

In this way, even though anti-freeze operation is unlikely to be performed when the outside air temperature is higher than the predetermined predicted freezing temperature, it is possible to avoid the cumbersome operation of having to select whether or not to fill the bath with a predetermined amount of hot water during anti-freeze operation each time the electric drain valve 36 is operated. Furthermore, if the outside air temperature drops suddenly and falls below the predetermined anti-freeze operation start temperature, anti-freeze operation can be performed without filling the bath with the predetermined amount of hot water, thereby preventing freezing of the bath circulation circuit 16.

In addition, if filling the bathtub 3 with the specified amount of water is not permitted in S15, or if the user does not operate the operation means 34 and neither option is selected, the anti-freeze operation control means 30 determines that the user wishes to avoid filling the bathtub 3 with the specified amount of water at an unexpected time.

However, if the outside air temperature drops over time to a temperature where there is a risk of freezing, anti-freeze operation must be performed. Therefore, the anti-freeze operation control means 30 continues to detect the outside air temperature using the outside air temperature sensor 31, and if the outside air temperature detected by the outside air temperature sensor 31 falls below the predetermined anti-freeze operation start temperature (Yes in S22), it starts anti-freeze operation 2 according to the table shown in Figure 3 (S23). After that, it turns the bath circulation pump 18 on and off according to the table shown in Figure 3, and then ends anti-freeze operation (Yes in S24), returns to S22, and repeats the process.

In this way, if the specified amount of water filling operation is not permitted, the specified amount of water filling operation will not be performed unexpectedly even if the outside temperature drops below the specified temperature.If the outside temperature drops suddenly and reaches the specified anti-freeze operation start temperature, the specified amount of water filling will not be performed and anti-freeze operation will be performed, thereby preventing at least the bath circulation pump 18 from freezing.

The present invention is not limited to the above embodiment and may be modified without departing from the spirit of the invention. For example, while the present invention uses specific examples of the predetermined predicted freezing temperature, the predetermined temperature, and the predetermined anti-freeze operation start temperature, these specific temperatures may all be the same (predicted predicted freezing temperature ≥ predetermined temperature ≥ predetermined anti-freeze operation start temperature. For example, all are 2°C).

REFERENCE SIGNS LIST 1 Hot water storage tank 3 Bathtub 6 Hot water storage temperature sensor 16 Bath circulation circuit 17 Indirect heat exchanger 18 Bath circulation pump 22 Bypass pipe 23 Flow path switching means 30 Anti-freeze operation control means 31 Outdoor air temperature sensor 32 Remote control 33 Display unit (notification means)
34 Operating means 35 Speaker 36 Electric drain plug

Claims (3)

The bathtub in the bathroom and
an electric drain plug that can be electrically opened and closed to drain the bathtub water from the bathtub;
a bath circulation circuit connected to the bathtub and circulating the bathtub water by a bath circulation pump;
A bathtub filling circuit for filling the bathtub with hot water;
a remote controller capable of issuing instructions for various operations and issuing notifications to prompt a user to perform specific operations;
In a bathtub device with an electric drain valve, the device is equipped with an outside air temperature sensor that detects the outside air temperature, a bathtub filling operation that fills the bathtub with a desired amount of hot water from the bathtub filling circuit, and a freeze prevention operation that circulates the bathtub water between the bathtub and the bath circulation circuit for a predetermined time to prevent the bath circulation circuit from freezing, and a control device that is communicably connected to the remote control.
When the remote control is used to start drainage by the electric drain valve, the control device issues a notification to the remote control to allow the user to select whether or not to perform the predetermined amount of water filling operation,
When the remote controller is used to select the filling operation, if the detected value of the outside air temperature sensor is equal to or lower than a predetermined temperature after the drainage is completed, the control device performs the filling operation of the predetermined amount,
A bathtub device with an electric drain plug, characterized in that after the specified amount of water filling operation is completed, if the detection value of the outside air temperature sensor is below the specified temperature, which is below the specified anti-freeze operation start temperature, the control device performs the anti-freeze operation. When the remote control is used to select the filling operation, if the detected value of the outside air temperature sensor is higher than the predetermined temperature after the drainage is completed, the control device does not perform the selected filling operation,
2. The bathtub device with an electric drain plug according to claim 1, wherein the control device performs the water filling operation with the predetermined amount when the detected value of the outside air temperature sensor falls below the predetermined temperature. A bathtub device with an electric drain valve as described in claim 1 or 2, characterized in that when the remote control is used to start draining using the electric drain valve, the control device issues a notification that allows the user to choose whether or not to perform the predetermined amount of water filling operation if the detected value of the outside air temperature sensor is equal to or lower than a predetermined predicted freezing temperature that is higher than the predetermined temperature.