JP7825518B2 - Bath equipment - Google Patents

Description

The technology disclosed in this specification relates to bath equipment.

Patent Document 1 discloses a bathtub device that includes a circulation path for circulating bathtub water, a bathtub circulation pump installed in the circulation path, a heating device installed in the circulation path for heating the water in the circulation path, a micro-bubble generator for generating micro-bubbles in the bathtub water, a temperature sensor capable of detecting the bathtub water temperature, and a control device. The control device is configured to perform two operations: a reheating operation that drives the bathtub circulation pump and operates the heating device to heat the bathtub water, and a micro-bubble generation operation that drives the bathtub circulation pump and generates micro-bubbles in the bathtub water using the micro-bubble generator.

Japanese Patent Application Laid-Open No. 2021-159588

In the bathtub device disclosed in Patent Document 1, during microbubble generation operation, bathtub water circulates through a circulation path. The water temperature drops due to heat dissipation as it passes through the circulation path. When the cooled water flows into the bathtub, the bathtub water temperature drops. Furthermore, during microbubble generation operation, the bathtub water dissipates more heat than when the water is not flowing. This also lowers the bathtub water temperature. A drop in bathtub water temperature during microbubble generation operation reduces the bather's comfort. To prevent the bathtub water temperature from dropping during microbubble generation operation, a configuration can be considered in which the microbubble generation operation and the reheating operation are simultaneously performed. However, the dissolved air content, which indicates the amount of air that can be dissolved in water, decreases as the water temperature increases. The lower the amount of air dissolved in water, the fewer microbubbles are generated by the microbubble generation operation, resulting in a decrease in the turbidity of the bathtub water. Therefore, simply running the fine bubble generating operation and the reheating operation simultaneously will reduce the cloudiness of the bathtub water, reducing the bather's comfort.

The present invention provides technology that can maintain the bather's comfort while the microbubble generator is operating.

A first aspect of the present technology includes a circulation path for circulating bathtub water, a bathtub circulation pump installed in the circulation path, a heating device installed in the circulation path for heating the water in the circulation path, a micro-bubble generator for generating micro-bubbles in the bathtub water, a temperature sensor capable of detecting the bathtub water temperature, and a control device. The control device is configured to drive the bathtub circulation pump and operate the heating device at a first heating amount to perform a reheating operation for heating the bathtub water, and a micro-bubble generation operation for driving the bathtub circulation pump and generating micro-bubbles in the bathtub water using the micro-bubble generator. If the bathtub water temperature during the micro-bubble generation operation falls below a predetermined temperature, the control device operates the heating device at a second heating amount that is less than the first heating amount to heat the bathtub water.

With the above configuration, the second heating amount of the heating device during micro-bubble generation operation is less than the first heating amount of the heating device during reheating operation, preventing a decrease in the amount of air dissolved in the water. This prevents a decrease in the bathtub water temperature during micro-bubble generation operation, and also prevents a decrease in the amount of micro-bubbles generated by the micro-bubble generation operation. In other words, a decrease in the cloudiness of the bathtub water can be prevented. This maintains the bather's comfort during micro-bubble generation operation.

In a second aspect, when the control device in the first aspect described above receives a start instruction to start the micro-bubble generating operation, it may identify the bathtub water temperature at the start of the micro-bubble generating operation, and identify the temperature obtained by subtracting the specific temperature from the bathtub water temperature at the start of the micro-bubble generating operation as the predetermined temperature.

If the bathtub water temperature during micro-bubble generating operation becomes significantly lower than the bathtub water temperature at the start of the micro-bubble generating operation, the bather's comfort will be compromised. Therefore, it is desirable to prevent the bathtub water temperature during micro-bubble generating operation from becoming significantly lower than the bathtub water temperature at the start of the micro-bubble generating operation. With the above configuration, the predetermined temperature is the bathtub water temperature at the start of the micro-bubble generating operation minus the specific temperature. Therefore, the heating device can be operated before the bathtub water temperature during micro-bubble generating operation becomes significantly lower than the bathtub water temperature at the start of the micro-bubble generating operation. This improves the bather's comfort.

In a third aspect, in the first or second aspect, the fine bubble generating operation may include a gas introduction operation in which gas is introduced into the fine bubble generating device, and a water supply operation in which, after the gas introduction operation, fine bubbles are generated in the bathtub water using the gas introduced in the gas introduction operation. The control device may operate the heating device at the second heating amount when the bathtub water temperature during the water supply operation falls below the predetermined temperature, and may operate the heating device at a third heating amount greater than the second heating amount when the bathtub water temperature during the gas introduction operation falls below the predetermined temperature.

Generally, during gas introduction operation, water containing no microscopic bubbles is discharged into the bathtub, while during water supply operation, water containing microscopic bubbles is discharged into the bathtub. Therefore, even if the temperature of the water heated by the heating device increases during gas introduction operation, the impact on the turbidity of the bathtub is small. Therefore, operating the heating device at the second heating amount during water supply operation can prevent a decrease in the turbidity of the bathtub, even if the heating device is operated at the third heating amount during gas introduction operation. Furthermore, by operating the heating device at the third heating amount during gas introduction operation, the bathtub water temperature can be increased more quickly during both water supply operation and gas introduction operation, compared to a configuration in which the heating device is operated at the second heating amount. This further improves user comfort.

In a fourth aspect, in any one of the first to third aspects, the control device may be further configured to perform a keep-warm operation to maintain the bathtub water temperature above a set temperature. The bathtub apparatus may further include a memory for storing either permission information indicating that the keep-warm operation is permitted or prohibition information indicating that the keep-warm operation is prohibited. When the permission information is stored in the memory, the control device may operate the heating device at the second heating amount if the bathtub water temperature during the fine-bubble generating operation falls below the predetermined temperature. When the prohibition information is stored in the memory, the control device may not operate the heating device even if the bathtub water temperature during the fine-bubble generating operation falls below the predetermined temperature.

When prohibition information is stored in memory, the bather does not want the bathtub water temperature to be automatically maintained above the warmth setting. In such a situation, if the heating device is activated and the bathtub water temperature rises, the bather may feel uncomfortable. With the above configuration, the control device operates the heating device at the second heating level when permission information is stored in memory, i.e., when the bather wants the bathtub water temperature to be automatically maintained above the warmth setting. On the other hand, the control device does not operate the heating device when prohibition information is stored in memory, i.e., when the bather does not want the bathtub water temperature to be automatically maintained above the warmth setting. This allows the bather's comfort to be maintained while minimizing discomfort.

1 is a diagram showing the configuration of a bath system 2 according to a first embodiment and the flow of water; A diagram showing another example of water flow in the bath system 2 according to the first embodiment. A diagram schematically showing yet another example of water flow in the bath system 2 of the first embodiment. A diagram schematically showing yet another example of water flow in the bath system 2 of the first embodiment. A diagram showing a schematic cross section of the bathtub adapter 132 of the bath system 2 of the first embodiment. FIG. 10 is a flowchart showing a heat retention process according to the first embodiment. FIG. 10 is a flowchart of a circulation process according to the first embodiment. FIG. 4 is a flowchart showing a first heating process according to the first embodiment. FIG. 10 is a flowchart showing a microbubble generating operation process according to the first embodiment. FIG. 10 is a flowchart showing a second heating process according to the first embodiment. A diagram showing the configuration of a bath system 302 according to a fourth embodiment and the flow of water.

(First Example)
(Configuration of bath system 2)
As shown in Figure 1, the bath system 2 of this embodiment includes a heat source unit 10, an air pressure dissolving unit 50, a bathtub 130, a bathtub adapter 132 provided on a wall 130a of the bathtub 130, and a control device 150. The heat source unit 10 is connected to a water supply source 200 and the air pressure dissolving unit 50. The air pressure dissolving unit 50 is connected to the heat source unit 10 and the bathtub 130.

(Configuration of heat source unit 10)
The heat source unit 10 is a unit for heating water flowing through the water passage of the heat source unit 10 and supplying the heated water to the bathtub 130. The heat source unit 10 includes a first heat source unit 12, a molten metal pouring passage 20, a return circulation passage 22, and an outward circulation passage 24.

The upstream end of the molten metal pouring passage 20 is connected to a water supply source 200 such as a city water supply, and the downstream end of the molten metal pouring passage 20 is connected to a circulation return passage 22. A molten metal filling valve 26 is provided in the molten metal pouring passage 20. The molten metal filling valve 26 opens and closes the molten metal pouring passage 20.

The upstream end of the return circulation path 22 is connected to the air pressurization dissolution unit 50, and the downstream end of the return circulation path 22 is connected to the first heat source unit 12. The upstream end of the forward circulation path 24 is connected to the first heat source unit 12, and the downstream end of the forward circulation path 24 is connected to the air pressurization dissolution unit 50. The first heat source unit 12 is a combustion heat source unit that heats water, for example, by burning gas. The first heat source unit 12 heats the water flowing in from the return circulation path 22 and sends the heated water to the forward circulation path 24. A return circulation path thermistor 22a is provided near the upstream end of the return circulation path 22 to detect the temperature of the water in the return circulation path 22. A forward circulation path thermistor 24a is provided near the downstream end of the forward circulation path 24 to detect the temperature of the water in the forward circulation path 24. Hereinafter, the temperatures detected by the return circulation path thermistor 22a and the forward circulation path thermistor 24a will be referred to as the "return path temperature" and the "forward path temperature," respectively.

The first circulation pump 30 is provided on the return circulation path 22 downstream of the connection point with the molten metal pouring path 20, and sends water from the return circulation path 22 toward the first heat source unit 12. The water flow switch 32 is provided on the return circulation path 22 between the first circulation pump 30 and the first heat source unit 12, and detects whether water is flowing through the return circulation path 22.

(Configuration of the air pressurized dissolution unit 50)
The air pressurized dissolution unit 50 comprises a tank 52, a heat source return path 60, a heat source forward path 68, a tank return path 74, a connecting passage 66, a tank forward path 64, a first bathtub water passage 62, a second bathtub water passage 70, a first switching valve 80, a second switching valve 82, a check valve 84, a tank water supply valve 86, a pressure pump 88, an air introduction path 100, and an air control valve 102.

The tank 52 is capable of storing water inside. A low water level electrode 52a and a high water level electrode 52b are installed inside the tank 52 to detect the water level inside the tank 52. The water level detected by the low water level electrode 52a (hereinafter referred to as the "lower limit water level") is lower than the water level detected by the high water level electrode 52b (hereinafter referred to as the "upper limit water level"). When the low water level electrode 52a and the high water level electrode 52b come into contact with the surface of the water stored in the tank 52, they output an ON signal to the control device 150. The tank 52 is used to generate pressurized aerated water, in which air is pressurized and dissolved in water.

One end of the heat source return line 60 is connected to the communication passage 66, and the other end of the heat source return line 60 is connected to the circulation return line 22 of the heat source unit 10. The communication passage 66 connects the first switching valve 80 and the second switching valve 82. The first switching valve 80 is connected to the communication passage 66, the first bathtub water channel 62, and the tank outbound line 64. The first switching valve 80 can switch between a first communication state (see Figures 1 and 2) in which the first bathtub water channel 62, the tank outbound line 64, and the communication passage 66 are connected; a second communication state (see Figure 3) in which the tank outbound line 64 and the first bathtub water channel 62 are connected; and a third communication state (see Figure 4) in which the tank outbound line 64 and the communication passage 66 are connected. The upstream end of the tank outbound line 64 is connected to the lower part of the tank 52, and the downstream end of the tank outbound line 64 is connected to the first switching valve 80. The tank outbound line 64 is provided with a check valve 84 that allows water to flow from the tank 52 toward the first switching valve 80 and prohibits water from flowing from the first switching valve 80 toward the tank 52. One end of the first bathtub water line 62 is connected to the first switching valve 80, and the other end of the first bathtub water line 62 is connected to the bathtub adapter 132.

The upstream end of the heat source outflow path 68 is connected to the circulation outflow path 24 of the heat source unit 10, and the downstream end of the heat source outflow path 68 is connected to the second switching valve 82. The second switching valve 82 is connected to the communication passage 66, the heat source outflow path 68, and the second bathtub water passage 70. The second switching valve 82 can switch between a fourth communication state (see Figures 1 and 4) in which the heat source outflow path 68 and the second bathtub water passage 70 are connected, and a fifth communication state (see Figures 2 and 3) in which the communication passage 66 and the second bathtub water passage 70 are connected. One end of the second bathtub water passage 70 is connected to the second switching valve 82, and the other end of the second bathtub water passage 70 is connected to the bathtub adapter 132.

The upstream end of the tank return line 74 is connected to the heat source outbound line 68, and the downstream end of the tank return line 74 is connected to the top of the tank 52. The tank return line 74 is provided with a tank water supply valve 86 and a pressure pump 88. The tank water supply valve 86 opens and closes the tank return line 74. The tank water supply valve 86 is provided upstream of the pressure pump 88. The pressure pump 88 pressurizes the water in the tank return line 74 and sends it downstream.

The upstream end of the air introduction path 100 is open to the atmosphere, and the downstream end is connected to the top of the tank 52. The air introduction path 100 introduces air into the tank 52. An air control valve 102 is provided in the air introduction path 100. The air control valve 102 opens and closes the air introduction path 100.

(Configuration of bathtub adapter 132)
Next, the bathtub adapter 132 provided on the wall 130a of the bathtub 130 will be described with reference to Figures 5(a)-(c). Figure 5(a) shows the flow of water through the bathtub adapter 132 when water flows from the bathtub 130 toward the first bathtub water channel 62 and from the second bathtub water channel 70 toward the bathtub 130 (e.g., the state shown in Figure 1). Figure 5(b) shows the flow of water through the bathtub adapter 132 when water flows from the bathtub 130 toward the second bathtub water channel 70 and from the first bathtub water channel 62 toward the bathtub 130 (e.g., the state shown in Figure 3). Figure 5(c) shows the flow of water through the bathtub adapter 132 when water flows from the second bathtub water channel 70 toward the bathtub 130 (e.g., the state shown in Figure 4).
Hereinafter, the up-down direction in FIG. 5 will be referred to as the up-down direction, and the left-right direction in FIG. 5 will be referred to as the front-rear direction.

The bathtub adapter 132 has a first water passage 136 and a second water passage 138. The first water passage 136 is connected to the first bathtub water passage 62, and the second water passage 138 is connected to the second bathtub water passage 70. The first water passage 136 branches into a first discharge passage 136a and a first suction passage 136b. The first discharge passage 136a is connected to a first discharge port 134a provided on the front surface 132a of the bathtub adapter 132. Water discharged from the first discharge port 134a into the bathtub 130 is discharged forward of the wall portion 130a of the bathtub 130, i.e., in a direction perpendicular to the inner surface 130b of the wall portion 130a of the bathtub 130. Although most of the water ejected from the first outlet 134a is ejected in a direction perpendicular to the inner surface 130b, some water is ejected diagonally forward, upward, and downward, i.e., in directions inclined to the inner surface 130b and in directions parallel to the inner surface 130b. That is, with regard to the amount of water ejected from the first outlet 134a, the amount of water in the perpendicular direction to the inner surface 130b is greater than the amount of water in the parallel direction to the inner surface 130b. In a modified example, as long as the amount of water ejected from the first outlet 134a in the perpendicular direction to the inner surface 130b is greater than the amount of water in the parallel direction to the inner surface 130b, the amount of water ejected in the direction inclined to the perpendicular direction to the inner surface 130b may be greater than the amount of water ejected in the perpendicular direction to the inner surface 130b. The first discharge passage 136a is provided with a check valve 140a that prevents water from flowing from the bathtub 130 toward the first bathtub water channel 62, and a fine-bubble generating nozzle 142 that is located upstream of the check valve 140a (toward the first bathtub water channel 62). The fine-bubble generating nozzle 142 reduces the pressure of the water passing through the fine-bubble generating nozzle 142. The first suction passage 136b is connected to a first suction port 134b located on the front surface 132a of the bathtub adapter 132. The first suction passage 136b is provided with a check valve 140b that prevents water from flowing from the first bathtub water channel 62 toward the bathtub 130.

The second water passage 138 branches into a second discharge passage 138a and a second suction passage 138b. The second suction passage 138b is connected to a second suction port 134c provided on the front surface 132a of the bathtub adapter 132. The second suction passage 138b is provided with a check valve 140c that prevents water from flowing from the second bathtub water passage 70 toward the bathtub 130. The second discharge passage 138a is connected to a second discharge port 134d provided on the underside 132b of the bathtub adapter 132. Water discharged from the second discharge port 134d is discharged downward, i.e., in a direction parallel to the inner surface 130b of the wall portion 130a of the bathtub 130. While most of the water discharged from the second outlet 134d is discharged in a direction parallel to the inner surface 130b, some water is discharged diagonally forward, diagonally backward, forward, and backward, i.e., in a direction inclined to the inner surface 130b and a direction perpendicular to the inner surface 130b. That is, the amount of water discharged from the second outlet 134d parallel to the inner surface 130b of the wall 130a is greater than the amount of water perpendicular to the inner surface 130b. In a modified example, the amount of water discharged in a direction inclined to the direction parallel to the inner surface 130b may be greater than the amount of water discharged parallel to the inner surface 130b, as long as the amount of water parallel to the inner surface 130b is greater than the amount of water perpendicular to the inner surface 130b. The second outlet path 138a is provided with a check valve 140d that prevents water from flowing from the bathtub 130 toward the second bathtub water path 70. In a modified example, most of the water ejected from the second outlet 134d may be ejected to the right or left (in a direction parallel to the inner surface 130b), etc.

(Configuration of control device 150)
The control device 150 shown in FIG. 1 controls the operation of each component of the heat source unit 10 and the air pressure dissolution unit 50. The control device 150 includes a memory 152. The memory 152 can store various settings, such as a water filling temperature setting, which is the temperature set during the water filling operation. The memory 152 also stores a keep-warm flag. The keep-warm flag indicates either ON, indicating that the keep-warm operation is permitted, or OFF, indicating that the keep-warm operation is prohibited. The control device 150 is configured to communicate with a remote control 154 that can be operated by a user. By operating the remote control 154, the user can instruct the start and end of the water filling operation, reheating operation, and microbubble generation operation. By operating the remote control 154, the user can change the keep-warm flag in the memory 152. By operating the remote control 154, the user can set the keep-warm end time, which is the time for executing the keep-warm operation.

The following describes the reheating operation, heat retention operation, and micro-bubble generation operation performed by the control device 150. The reheating operation, micro-bubble generation operation, and heat retention operation are operations performed after the bath filling operation is completed, i.e., when water is stored in the bathtub 130. The bath filling operation heats water supplied from the water supply source 200 and uses the heated water to store a predetermined amount of water at the bath filling set temperature in the bathtub 130. Details will not be explained here.

(Reheating operation)
The reheating operation is initiated when the user issues a command to start the reheating operation via the remote control 154. As shown in FIG. 1 , the control device 150 sets the first switching valve 80 to the first communication state and the second switching valve 82 to the fourth communication state when starting the reheating operation. From this state, the control device 150 drives the first circulation pump 30 and starts heating water using the first heat source unit 12. The control device 150 controls the operation of the first heat source unit 12 so that the heating amount of the first heat source unit 12 becomes the first heat source heating amount. The first heat source heating amount is equal to or greater than the low heating amount, which is the heating amount when the first heat source unit 12 is continuously operated at minimum heating power. As a result, water from the bathtub 130 is sent to the first heat source unit 12 via the bathtub adapter 132, the first bathtub water passage 62, the first switching valve 80, the communication passage 66, the heat source return line 60, and the circulation return line 22. Water heated by the first heat source unit 12 is returned to the bathtub 130 via the circulation outward path 24, the heat source outward path 68, the second switching valve 82, the second bathtub water passage 70, and the bathtub adapter 132. That is, during reheating operation, water flows through the first circulation water passage, which is composed of the first bathtub water passage 62, the connecting passage 66, the heat source return path 60, the circulation return path 22, the first heat source unit 12, the circulation outward path 24, the heat source outward path 68, and the second bathtub water passage 70. When the return path temperature is equal to or higher than the bath filling temperature setting and the time since the start of the reheating operation is equal to or longer than the reheating determination time, the control device 150 stops the first circulation pump 30 and terminates water heating by the first heat source unit 12. The control device 150 then notifies the user via the remote control 154 that the reheating operation has been completed and terminates the reheating operation.

(Keep warm operation)
The keep-warm operation is an operation for maintaining the temperature of the water in the bathtub 130 at or above the keep-warm set temperature. The keep-warm set temperature is the same as the bath filling set temperature, or a temperature obtained by subtracting a first predetermined value (e.g., 1°C) from the bath filling set temperature. When the keep-warm flag "ON" is stored in memory 152, the control device 150 executes the keep-warm process shown in Figure 6.

In S10, the control device 150 sets the first switching valve 80 to the first communication state, the second switching valve 82 to the fourth communication state, and the tank water supply valve 86 to the closed state (see Figure 1). The control device 150 also drives the first circulation pump 30. This causes water to flow through the first circulation water channel, as shown in Figure 1.

In S12 of FIG. 6, the control device 150 monitors whether the first heat retention determination time has elapsed since the first circulation pump 30 was driven. When the first circulation pump 30 is driven and water flows into the bathtub 130, the water in the bathtub 130 is stirred and the temperature of the water in the bathtub 130 is equalized. The first heat retention determination time is set to the time required for the water in the bathtub 130, after its temperature has been equalized, to reach the circulation return thermistor 22a. If the first heat retention determination time has elapsed since the first circulation pump 30 was driven, the control device 150 determines YES in S12 and proceeds to S14.

In addition, in S20, while monitoring S12, the control device 150 also monitors whether the time since the start of the warming process (hereinafter referred to as the "warming operation time") has passed the warming end time. If the warming operation time has passed the warming end time, the control device 150 determines YES in S20 and the process proceeds to S22. In S22, the control device 150 stops the first circulation pump 30. When S22 is completed, the control device 150 ends the process of FIG. 6.

After S12 returns YES, the control device 150 determines in S14 whether the return path temperature is below the keep-warm judgment temperature. The keep-warm judgment temperature may be the same as the keep-warm setting temperature, or may be the keep-warm setting temperature minus a second predetermined value (e.g., 1°C). If the return path temperature is below the keep-warm judgment temperature, the control device 150 determines YES in S14 and proceeds to S16. On the other hand, if the return path temperature is equal to or higher than the keep-warm judgment temperature, the control device 150 determines NO in S14 and proceeds to S34. Note that the return path temperature after the first keep-warm judgment time has elapsed is the same as the temperature of the water in the bathtub 130 (hereinafter referred to as the "bathtub water temperature"). That is, in S14, the control device 150 determines whether the bathtub water temperature is below the keep-warm judgment temperature.

In S16, the control device 150 controls the operation of the first heat source unit 12 so that the heating amount of the first heat source unit 12 becomes the second heat source heating amount. The second heat source heating amount is a heating amount equal to or greater than the low heating amount of the first heat source unit 12. The second heat source heating amount may be the same as or different from the first heat source heating amount.

In S30, the control device 150 monitors whether the return path temperature is equal to or higher than the keep-warm setting temperature. If the return path temperature is equal to or higher than the keep-warm setting temperature, the control device 150 determines YES in S30 and proceeds to S32.

In addition, in S40, the control device 150 monitors whether the keep-warm operation time has exceeded the keep-warm end time, simultaneously with monitoring in S30. If the keep-warm operation time has exceeded the keep-warm end time, the control device 150 determines YES in S40 and proceeds to S42. In S42, the control device 150 stops the first circulation pump 30 and the first heat source unit 12. When S42 is completed, the control device 150 ends the processing of FIG. 6.

After S30 returns YES, in S32 the control device 150 stops the first heat source unit 12. Then, in S34, the control device 150 stops the first circulation pump 30. When S34 ends, processing proceeds to S50.

In S50, the control device 150 monitors whether the second heat retention determination time (e.g., 10 minutes) has elapsed since the first circulation pump 30 was stopped. If the second heat retention determination time has elapsed since the first circulation pump 30 was stopped, the control device 150 determines YES in S50 and the process proceeds to S52. In S52, the control device 150 drives the first circulation pump 30. When S52 ends, the process returns to S12.

In addition, in S54, the control device 150 simultaneously monitors whether the keep-warm operation time has exceeded the keep-warm end time. If the keep-warm operation time has exceeded the keep-warm end time, the control device 150 determines YES in S54 and ends the processing of Figure 6.

As described above, in the heat retention process, if the return path temperature is below the heat retention judgment temperature (YES in S14), the first heat source unit 12 operates (S16), and if the return path temperature is equal to or higher than the heat retention setting temperature (YES in S30), the first heat source unit 12 stops (S32). Therefore, the heat retention process prevents the bathtub water temperature from falling below the heat retention judgment temperature, and the bathtub water temperature can be maintained at or above the heat retention setting temperature.

(Fine bubble generation operation)
The fine bubble generating operation is an operation for generating fine bubbles in the bathtub 130 shown in Fig. 1. When the control device 150 receives a start instruction from the remote control 154 to instruct the start of the fine bubble generating operation, it executes the processes shown in Figs. 7 to 10.

(Circulation treatment, first heating treatment; Figures 7 and 8)
When receiving a start instruction from the remote control 154, the control device 150 executes the circulating process of Fig. 7 and the first heating process of Fig. 8. The control device 150 executes the circulating process of Fig. 7 and the first heating process of Fig. 8 in parallel.

(Circulation process; Figure 7)
In S70 of Fig. 7, the control device 150 executes the first circulation operation. Specifically, the control device 150 sets the first switching valve 80 to the first communication state, the second switching valve 82 to the fourth communication state, and closes the tank water supply valve 86 (see Fig. 1). The control device 150 also drives the first circulation pump 30. As a result, water flows through the first circulation water channel, as shown in Fig. 1.

In S72 of FIG. 7, the control device 150 monitors whether the time since the start of the first circulation operation has exceeded the first circulation judgment time (e.g., 10 seconds). The first circulation time is set to the time required for the water that has been stagnating in the first circulation water channel before the micro-bubble generating operation is started to be drained into the bathtub 130. If the time since the start of the first circulation operation has exceeded the first circulation judgment time, the control device 150 determines YES in S72 and proceeds to S100.

In addition, in S80, while monitoring S72, the control device 150 simultaneously monitors whether an end instruction has been received from the remote control 154. The end instruction is a signal received from the remote control 154 when the user operates the remote control 154 to end the microbubble generation operation. If the control device 150 receives an end instruction from the remote control 154, it determines YES in S80, and processing proceeds to S82. In S82, the control device 150 stops the first circulation pump 30. When S82 ends, the control device 150 ends the processing of FIG. 7.

In addition, in S90, the control device 150, simultaneously with monitoring S72 and S80, monitors whether the time since the start of the first circulation operation has exceeded the specified temperature time. The specified temperature time is set to the time required for the water in the bathtub 130 to reach the circulation return thermistor 22a. The specified temperature time is shorter than the first circulation judgment time. If the time since the start of the first circulation operation has exceeded the specified temperature time, the control device 150 determines YES in S90 and proceeds to S92.

In S92, the control device 150 stores the return temperature in memory 152 as the starting temperature, which is the bathtub water temperature at the start of the microbubble generation operation. The starting temperature is the temperature used in the second heating process (see Figure 10) described below.

After a YES determination is made in S72, the control device 150 performs the second circulation operation in S100. Specifically, the control device 150 sets the first switching valve 80 to the first communication state, the second switching valve 82 to the fifth communication state, and the tank water supply valve 86 to the open state (see FIG. 2). In this case, as shown in FIG. 2, water flows through the second circulation water passage, which is composed of the tank outbound path 64, the communication passage 66, the heat source return path 60, the circulation return path 22, the first heat source unit 12, the circulation outbound path 24, the heat source outbound path 68, the tank return path 74, and the tank 52.

In S102 of FIG. 7, the control device 150 monitors whether the time since the start of the second circulation operation has exceeded the second circulation judgment time (e.g., 10 seconds). The second circulation judgment time is set to the time required to mix the water in the second circulation water channel. If the time since the start of the second circulation operation has exceeded the second circulation judgment time, the control device 150 determines YES in S102 and proceeds to S104.

Simultaneously with monitoring in S102 , the control device 150 monitors in S106 whether an end instruction has been received from the remote control 154. If an end instruction has been received from the remote control 154, the control device 150 determines YES in S106 and proceeds to S104.

In S104, the control device 150 stops the first circulation pump 30. After S104 is completed, the control device 150 ends the processing shown in Figure 7.

As will be explained in more detail later, immediately after the micro-bubble generating operation process (see FIG. 9) described below is initiated, water is discharged into the bathtub 130 from the first outlet 134a of the bathtub adapter 132 (see FIG. 5(b)). For example, after a relatively long time has passed since the completion of the bath filling operation, the temperature of the water in the tank 52 and the water channel drops, and the temperature of the water discharged into the bathtub 130 may differ significantly from the bathtub water temperature. In such a situation, if the water discharged into the bathtub 130 hits the bather directly, it may cause discomfort to the bather. Therefore, in the first circulation operation (S70) described above, water that had been stagnating in the first circulation channel before the micro-bubble generating operation was initiated is drained into the bathtub 130 from the second outlet 134d of the bathtub adapter 132, and the water in the first circulation channel is replaced with the relatively warmer water from the bathtub 130 (see FIG. 5(a)). By discharging low-temperature water from the second outlet 134d into the bathtub 130, direct contact of low-temperature water with the bather during the first circulation operation can be prevented. Furthermore, the temperature of the water in the first circulation water channel can be increased. Furthermore, during the second circulation operation (S100), the water in the second circulation water channel is mixed. The first circulation water channel (see FIG. 1) and the second circulation water channel (see FIG. 2) share the tank outbound path 64, the heat source return path 60, the circulation return path 22, the circulation outbound path 24, and the heat source outbound path 68. After the first circulation operation is completed, high-temperature water remains in the heat source return path 60, the circulation return path 22, the circulation outbound path 24, and the heat source outbound path 68. Therefore, the mixing of the water in the second circulation water channel increases the temperature of the low-temperature water in the second circulation water channel. Therefore, the circulation process increases the temperature of the water in each water channel of the bath system 2, preventing the user from being hit directly by cold water and feeling uncomfortable immediately after the microbubble generation operation process begins.

(First heat treatment; FIG. 8)
In S110 of Fig. 8, the control device 150 determines whether or not the cyclic process (see Fig. 7) is being executed. If the cyclic process is being executed, the control device 150 determines YES in S110, and the process proceeds to S112. On the other hand, if the cyclic process is not being executed, the control device 150 determines NO in S110, and the process proceeds to S130.

In S112, the control device 150 determines whether the return path temperature is equal to or higher than the first circulation judgment temperature (e.g., 30°C). If the return path temperature is equal to or higher than the first circulation judgment temperature, the control device 150 determines YES in S112 and proceeds to S114. On the other hand, if the return path temperature is not equal to or higher than the first circulation judgment temperature, the control device 150 determines NO in S112 and proceeds to S120.

In S114, if the first heat source unit 12 is operating, the control device 150 stops the first heat source unit 12. When S114 ends, processing returns to S110.

Furthermore, in S120, the control device 150 determines whether the return path temperature is less than a second circulation judgment temperature (e.g., 25°C). The second circulation judgment temperature is a temperature lower than the first circulation judgment temperature. If the return path temperature is less than the second circulation judgment temperature, the control device 150 determines YES in S120 and proceeds to S122. On the other hand, if the return path temperature is not less than the second circulation judgment temperature, the control device 150 determines NO in S120 and proceeds to S124.

In S122, the control device 150 controls the operation of the first heat source unit 12 so that the heating amount of the first heat source unit 12 becomes the third heat source heating amount. The third heat source heating amount is a heating amount equal to or greater than the low heating amount of the first heat source unit 12. The third heat source heating amount may be the same as or different from the first heat source heating amount. When S122 ends, processing returns to S110.

In S124, the control device 150 controls the operation of the first heat source unit 12 so that the heating amount of the first heat source unit 12 becomes the fourth heat source heating amount. The fourth heat source heating amount is a heating amount that is less than the third heat source heating amount and is also less than the low heating amount of the first heat source unit. The fourth heat source heating amount is achieved by the first heat source unit 12 alternately operating between an ON state in which the first heat source unit 12 is operating at minimum heating power and an OFF state in which the first heat source unit 12 is stopped. When S124 ends, the processing returns to S110.

Furthermore, in S130 after a NO judgment is made in S110, if the first heat source unit 12 is operating, the control device 150 stops the first heat source unit 12. When S130 ends, the control device 150 ends the processing of FIG. 8.

As described above, in the first heating process, the first heat source unit 12 operates (S122, S124). Therefore, while the first circulation operation (S70 in FIG. 7) is being performed, the first heat source unit 12 can increase the temperature of the water in the first circulation water channel (see FIG. 1). Furthermore, while the second circulation operation (S100 in FIG. 7) is being performed, the first heat source unit 12 can increase the temperature of the water in the second circulation water channel (see FIG. 2).

(Fine bubble generating operation process, second heating process; Figures 9 and 10)
When the circulation process (see FIG. 7) and the first heating process (see FIG. 8) are completed, the control device 150 executes the fine bubble generating operation process of FIG. 9. Note that when the heat retention flag "ON" is stored in the memory 152, the control device 150 executes the second heating process (see FIG. 10) in parallel with the fine bubble generating operation process, and when the heat retention flag "OFF" is stored in the memory 152, the control device 150 does not execute the second heating process (see FIG. 10). Note that in a modified example, the user may be able to operate the remote control 154 to set whether or not the second heating process (see FIG. 10) is executed.

(Fine bubble generation operation process; Figure 9)
In S140, the control device 150 executes the air introduction operation. Specifically, the control device 150 sets the first switching valve 80 to the third communication state, the second switching valve 82 to the fourth communication state, the tank water supply valve 86 to the closed state, and the air control valve 102 to the open state (see FIG. 4 ). The control device 150 also drives the first circulation pump 30. As a result, as shown in FIG. 4 , water is sucked out of the tank 52, and air is introduced into the tank 52 via the air introduction path 100. The water sucked out of the tank 52 passes through the tank outflow path 64, the first switching valve 80, the communication path 66, the heat source return path 60, the circulation return path 22, the first heat source unit 12, the circulation outflow path 24, the heat source outflow path 68, the second switching valve 82, the second bathtub water path 70, and the bathtub adapter 132, and is then drained into the bathtub 130.

In S142, the control device 150 monitors whether the water level in the tank 52 has fallen below the lower limit water level. If the water level in the tank 52 has fallen below the lower limit water level, the control device 150 determines YES in S142 and the process proceeds to S144.

In addition, in S146, the control device 150 monitors whether an end instruction has been received from the remote control 154, simultaneously with monitoring S142. If an end instruction has been received from the remote control 154, the control device 150 determines YES in S146 and the process proceeds to S148. In S148, the control device 150 stops the first circulation pump 30. When S148 ends, the control device 150 ends the process of FIG. 9.

In S144 after a YES determination is made in S142, the control device 150 closes the air control valve 102 and stops the first circulation pump 30. This ends the air introduction operation. In a modified example, the control device 150 may close the air control valve 102 in S144 without stopping the first circulation pump 30. In other words, the control device 150 may start the water supply operation described below while the first circulation pump 30 is running.

At S150, the control device 150 executes water supply operation. Specifically, the control device 150 sets the first switching valve 80 to the second communication state, the second switching valve 82 to the fifth communication state, and the tank water supply valve 86 to the open state (see FIG. 3). The control device 150 also maintains the air control valve 102 in a closed state. The control device 150 also drives the first circulation pump 30 and the pressurizing pump 88. As a result, as shown in FIG. 3, water from the bathtub 130 is supplied to the tank 52 via the bathtub adapter 132, the second bathtub water passage 70, the second switching valve 82, the communication passage 66, the heat source return path 60, the circulation return path 22, the first heat source unit 12, the circulation outward path 24, the heat source outward path 68, and the tank return path 74. Water pressurized by the pressurizing pump 88 is supplied from the tank return path 74 to the tank 52. Air-dissolved pressurized water is generated inside the tank 52 by pressurizing and dissolving air in water. The air-dissolved pressurized water is then supplied from the tank 52 to the bathtub 130 via the tank outflow path 64, the first switching valve 80, the first bathtub water passage 62, and the bathtub adapter 132. That is, during water supply operation, water flows through a third circulation water passage consisting of the second bathtub water passage 70, the communication passage 66, the heat source return path 60, the circulation return path 22, the first heat source unit 12, the circulation outflow path 24, the heat source outflow path 68, the tank return path 74, the tank 52, the tank outflow path 64, and the first bathtub water passage 62. The air-dissolved pressurized water generated in the tank 52 is decompressed to below atmospheric pressure when passing through the fine bubble generating nozzle 142 (see FIG. 5B) in the bathtub adapter 132, and then pressurized to atmospheric pressure when sprayed into the bathtub 130, generating fine bubbles in the water in the bathtub 130. Hereinafter, the tank 52 and bathtub adapter 132 may be collectively referred to as the "microbubble generator."

In S152 of FIG. 9, the control device 150 monitors whether the water level in the tank 52 is above the upper water level. If the water level in the tank 52 is above the upper water level, the control device 150 determines YES in S152 and proceeds to S154.

In addition, in S156, the control device 150 monitors whether an end instruction has been received from the remote control 154, simultaneously with monitoring S152. If an end instruction has been received from the remote control 154, the control device 150 determines YES in S156 and the process proceeds to S158. In S158, the control device 150 stops the first circulation pump 30 and the pressure pump 88. When S158 ends, the control device 150 ends the process of FIG. 9.

After S152 returns YES, in S154 the control device 150 stops the first circulation pump 30 and the pressure pump 88. This ends the water supply operation.

In S160 after S154, the control device 150 determines whether the number of times the air introduction operation has been performed is a predetermined number or more (e.g., five times). If the number of times is equal to or greater than the predetermined number, the control device 150 determines YES in S160 and ends the processing of FIG. 9. On the other hand, if the number of times is not equal to or greater than the predetermined number, the control device 150 determines NO in S160 and returns to S140. Note that, in a modified example, the control device 150 may execute S160 without S154. In this modified example, if the control device 150 determines YES in S160, it stops the first circulation pump 30 and the pressure pump 88 and ends the processing of FIG. 9. On the other hand, if the control device 150 determines NO in S160, it stops the pressure pump 88 without stopping the first circulation pump 30, and the processing proceeds to S140. That is, in this modified example, the control device 150 starts the air introduction operation, which is performed after the water supply operation, while the first circulation pump 30 is running.

As described above, during air introduction operation, air is introduced into the tank 52 via the air introduction path 100. During water supply operation, air-dissolved pressurized water is generated inside the tank 52 using the air in the tank. The generated air-dissolved pressurized water passes through the micro-bubble generating nozzle 142 (see Figure 5(b)) in the bathtub adapter 132, generating micro-bubbles in the water in the bathtub 130. In this way, by repeatedly performing the air introduction operation and the water supply operation, micro-bubbles can be generated in the water in the bathtub 130.

(Second heat treatment; Figure 10)
In S190 of Fig. 10, the control device 150 identifies a first heating determination temperature using the start temperature (see S92 of Fig. 7) stored in the memory 152. The first heating determination temperature is a temperature used to determine whether or not to operate the first heat source unit 12 during the fine bubble generating operation. The control device 150 identifies the temperature obtained by subtracting a fourth predetermined value (e.g., 1°C) from the start temperature as the first heating determination temperature.

In S200, the control device 150 monitors whether the return path temperature has fallen below the first heating determination temperature. If the return path temperature has fallen below the first heating determination temperature, the control device 150 determines YES in S200 and proceeds to S210. The reason the return path temperature drops during micro-bubble generation operation is as follows: During micro-bubble generation operation, the water in the bathtub 130 circulates through the third circulation water channel (see Figure 3), etc. The water temperature drops due to heat dissipation while passing through the third circulation water channel. Furthermore, during micro-bubble generation operation, the water in the bathtub 130 is flowing, and therefore dissipates more heat than when the water is not flowing. These heat dissipation factors cause the return path temperature to drop during micro-bubble generation operation.

In addition, in S202, the control device 150 monitors whether the microbubble generation operation process (see Figure 9) has ended, simultaneously with monitoring S200. If the microbubble generation operation process has ended, the control device 150 determines YES in S202 and ends the process of Figure 10.

In S210 after a YES determination in S200, the control device 150 determines whether the water supply operation (S140 or S160 in FIG. 9) is currently being performed. If the water supply operation is currently being performed, the control device 150 determines a YES determination in S210, and processing proceeds to S212. On the other hand, if the water supply operation is not currently being performed, i.e., if the air introduction operation (see S150 in FIG. 9) is currently being performed, the control device 150 determines a NO determination in S210, and processing proceeds to S214.

In S212, the control device 150 controls the operation of the first heat source unit 12 so that the heating amount of the first heat source unit 12 becomes the fifth heat source heating amount. The fifth heat source heating amount is a heating amount less than the low heating amount of the first heat source unit 12 and is smaller than the first heat source heating amount of the first heat source unit 12 during reheating operation. The fifth heat source heating amount is achieved by the first heat source unit 12 alternately operating between an on state in which the first heat source unit 12 is operating at minimum heating power and an off state in which the first heat source unit 12 is stopped. The fifth heat source heating amount may be the same as or different from the fourth heat source heating amount.

In S214, the control device 150 controls the operation of the first heat source unit 12 so that the heating amount of the first heat source unit 12 becomes the sixth heat source heating amount. The sixth heat source heating amount is equal to or greater than the low heating amount of the first heat source unit 12 and is greater than the fifth heat source heating amount. The sixth heat source heating amount may be the same as or different from the first heat source heating amount of the first heat source unit 12 during reheating operation.

In S220, the control device 150 monitors whether the outward temperature is equal to or higher than the second heating determination temperature. The second heating determination temperature is set to a temperature lower than the temperature at which the bather would feel uncomfortable even if the water ejected from the first outlet 134a hit them directly. If the outward temperature is equal to or higher than the second heating determination temperature, the control device 150 determines YES in S220 and proceeds to S222.

In S222, the control device 150 stops the first heat source unit 12. When S222 ends, processing returns to S200.

In addition, in S230, the control device 150 monitors whether the operation (water supply operation or air introduction operation) during the microbubble generation operation process (see Figure 9) is switched, simultaneously with monitoring S220. If the operation is switched, the control device 150 determines YES in S230 and the process proceeds to S232.

In S232, the control device 150 changes the heating amount of the first heat source unit 12. Specifically, when operation during the fine bubble generation operation process (see FIG. 9) switches from water supply operation to air introduction operation, the control device 150 changes the heating amount of the first heat source unit 12 from the fifth heat source heating amount to the sixth heat source heating amount. Furthermore, when operation during the fine bubble generation operation process (see FIG. 9) switches from air introduction operation to water supply operation, the control device 150 changes the heating amount of the first heat source unit 12 from the sixth heat source heating amount to the fifth heat source heating amount. When S232 ends, processing returns to S220.

Furthermore, in S240, the control device 150 monitors whether the fine bubble generation operation process (see Figure 9) has ended, simultaneously with monitoring S220 and S230. If the fine bubble generation operation process has ended, the control device 150 determines YES in S240 and proceeds to S242. In S242, the control device 150 stops the first heat source unit 12. When S242 ends, the control device 150 ends the processing of Figure 10.

As described above, the second heating process can prevent the return temperature from falling below the first heating judgment temperature. The return temperature during the second heating process is approximately the same as the bathtub water temperature. Therefore, the bathtub water temperature during the fine bubble generation operation process can be prevented from falling below the first heating judgment temperature. Furthermore, when water supply operation is being performed (YES in S210), the control device 150 operates the first heat source unit 12 at the fifth heat source heating amount (S212), and when air introduction operation is being performed (NO in S210), the control device 150 operates the first heat source unit 12 at the sixth heat source heating amount, which is greater than the fifth heat source heating amount (S214). In water supply operation, water heated by the fifth heat source heating amount is discharged into the bathtub 130 from the first outlet 134a (see Figure 5(b)) of the bathtub adapter 132, and in air introduction operation, water heated by the sixth heat source heating amount is discharged into the bathtub 130 from the second outlet 134d (see Figure 5(c)) of the bathtub adapter 132. This prevents the high-temperature water heated by the sixth heat source heating amount from hitting the bather directly.

As described above, as shown in FIG. 1, the bath system 2 (an example of a "bath device") comprises a first circulation water channel and a third circulation water channel (an example of a "circulation channel") that circulate the water in the bathtub 130, a first circulation pump 30 (an example of a "bathtub circulation pump") provided in the first circulation water channel and the third circulation water channel, a first heat source unit 12 (an example of a "heating device") provided in the first circulation water channel and the third circulation water channel and that heats the water in the first circulation water channel and the third circulation water channel, a micro-bubble generator that generates micro-bubbles in the water in the bathtub 130, a circulation return thermistor 22a (an example of a "temperature sensor") that can detect the bathtub water temperature, and a control device 150. The control device 150 is configured to perform two operations: a reheating operation in which the first circulation pump 30 is driven and the first heat source unit 12 is operated at a first heat-source heating amount (an example of a "first heating amount") to heat the water in the bathtub 130; and a micro-bubble generating operation in which the first circulation pump 30 is driven and the micro-bubble generator is used to generate micro-bubbles in the water in the bathtub 130. When the bathtub water temperature during the micro-bubble generating operation is equal to or lower than a first heating determination temperature (an example of a "predetermined temperature") (YES in S200 of FIG. 10), the control device 150 operates the first heat source unit 12 at a fifth heat-source heating amount (an example of a "second heating amount") that is less than the first heat-source heating amount to heat the water in the bathtub 130 (S212). With this configuration, the fifth heat-source heating amount is less than the first heat-source heating amount, which is the heating amount of the first heat source unit 12 during the reheating operation, thereby preventing a decrease in the amount of air dissolved in the water. This reduces the amount of micro-bubbles generated by the micro-bubble generating operation, preventing the water in the bathtub 130 from becoming less cloudy. This helps maintain user comfort during the micro-bubble generating operation.

Furthermore, when the control device 150 receives a start command to start the fine-bubble generating operation, it determines the bathtub water temperature at the start of the fine-bubble generating operation and determines the temperature obtained by subtracting a fourth predetermined value (an example of a "specific temperature") from the bathtub water temperature at the start of the fine-bubble generating operation as the first heating determination temperature (S190 in Figure 10). According to the above configuration, the first heating determination temperature is the temperature obtained by subtracting the fourth predetermined value from the bathtub water temperature at the start of the fine-bubble generating operation. Therefore, the first heat source unit 12 can be operated before the bathtub water temperature during the fine-bubble generating operation becomes significantly lower than the bathtub water temperature at the start of the fine-bubble generating operation. This improves the bather's comfort.

Also, as shown in Figure 5, the micro-bubble generation operation includes an air introduction operation ("gas introduction operation") (S140 in Figure 9) (see Figure 5(c)) in which air (an example of "gas") is introduced into the micro-bubble generator, and a water supply operation (S150 in Figure 9) (see Figure 5(b)) in which, after the air introduction operation, the air introduced in the air introduction operation is used to generate micro-bubbles in the water in the bathtub 130. When the bathtub water temperature during water supply operation is equal to or lower than the first heating determination temperature (YES in S200 and YES in S210 in FIG. 10 ), the control device 150 operates the first heat source unit 12 at the fifth heat source heating amount (S212). When the bathtub water temperature during air introduction operation is equal to or lower than the first heating determination temperature (YES in S200 and NO in S210), the control device 150 operates the first heat source unit 12 at the sixth heat source heating amount (an example of the "third heating amount"), which is greater than the fifth heat source heating amount (S214). Generally, during air introduction operation, water without microbubbles is discharged into the bathtub 130, and during water supply operation, water containing microbubbles is discharged into the bathtub 130. Therefore, even if the temperature of the water heated by the first heat source unit 12 increases during air introduction operation, the effect on the turbidity of the bathtub 130 is small. Therefore, operating the first heat source unit 12 at the fifth heat source heating amount during water supply operation can prevent a decrease in the opacity of the bathtub 130, even if the first heat source unit 12 is operated at the sixth heat source heating amount during air introduction operation. Furthermore, operating the first heat source unit 12 at the sixth heat source heating amount during air introduction operation can increase the bathtub water temperature more quickly in both water supply operation and air introduction operation compared to a configuration in which the first heat source unit 12 is heated at the fifth heat source heating amount. This can further improve user comfort.

As shown in FIG. 6, the control device 150 is further configured to perform a heat retention operation to maintain the bathtub water temperature above the heat retention setting temperature. As shown in FIG. 1, the bath system 2 further includes a memory 152 that stores a heat retention flag indicating either "ON" (an example of "permission information"), indicating that the heat retention operation is permitted, or "OFF" (an example of "prohibition information"), indicating that the heat retention operation is prohibited. When the heat retention flag is "ON," if the bathtub water temperature during the fine-bubble generating operation falls below the first heating determination temperature (YES in S200 of FIG. 10), the control device 150 operates the first heat source unit 12 at the fifth heat source heating amount (S212). When the heat retention flag is "OFF," the control device 150 does not operate the first heat source unit 12 even if the bathtub water temperature during the fine-bubble generating operation falls below the first heating determination temperature. With the above configuration, the control device 150 operates the first heat source unit 12 at the fifth heat source heating amount when the heat retention flag is "ON," i.e., when the bather wants the bathtub water temperature to be automatically maintained above the heat retention set temperature. On the other hand, the control device 150 does not operate the first heat source unit 12 when the heat retention flag is "OFF," i.e., when the bather does not want the bathtub water temperature to be automatically maintained above the heat retention set temperature. This allows the bather's comfort to be maintained and discomfort to be reduced.

(Second Example)
The second embodiment differs from the first embodiment in the process executed in S220 of FIG. 10 . In the second embodiment, the control device 150 monitors whether the return path temperature is equal to or higher than a third heating determination temperature in S220. The third heating determination temperature may be, for example, the same as the first heating determination temperature, or may be a temperature higher than the first heating determination temperature. If the return path temperature is equal to or higher than the third heating determination temperature, the control device 150 determines YES in S220, and the process proceeds to S222.

(Third Example)
The third embodiment differs from the first embodiment in the processing executed in S220 of Fig. 10. In the third embodiment, the control device 150 monitors in S220 whether the time since the first heat source unit 12 was operated in S212 or S214 has elapsed a second heating determination time (e.g., 3 minutes). If the time since the first heat source unit 12 was operated has elapsed the second heating determination time, the control device 150 determines YES in S220, and the processing proceeds to S222.

(Fourth Example)
A bath system 302 of the fourth embodiment will be described with reference to Figure 11. The bath system 302 of the fourth embodiment differs from the bath system 2 of the first embodiment (see Figure 1) in the configuration of the heat source unit 310. Note that components common to the bath system 302 of this modified example and the bath system 2 of the first embodiment will be assigned the same reference numerals and their description will be omitted.

The heat source unit 310 of the bath system 302 includes a heat exchange unit 312, a hot water supply path 20, a circulation return path 22, and a circulation outward path 24. The heat exchange unit 312 includes a heat exchanger 320, a second heat source unit 322, a unit outward path 324, a unit return path 326, and a second circulation pump 328 provided in the unit return path 326. The upstream end of the unit outward path 324 is connected to the second heat source unit 322, and the downstream end of the unit outward path 324 is connected to the heat exchange unit 312. The upstream end of the unit return path 326 is connected to the heat exchange unit 312, and the downstream end of the unit return path 326 is connected to the second heat source unit 322. The second circulation pump 328 sends water from the unit return path 326 toward the second heat source unit 322.

The heat exchange unit 312 includes a first heat exchange path 330, a second heat exchange path 332, and a flow control valve 334 provided in the first heat exchange path 330. The upstream end of the first heat exchange path 330 is connected to the unit outbound path 324, and the downstream end of the first heat exchange path 330 is connected to the unit return path 326. The upstream end of the second heat exchange path 332 is connected to the circulation return path 22, and the downstream end of the second heat exchange path 332 is connected to the circulation outbound path 24. The flow control valve 334 adjusts the amount of water flowing through the first heat exchange path 330. Hereinafter, the water path consisting of the unit outbound path 324, the first heat exchange path 330, the unit return path 326, and the second heat source unit 322 will be referred to as the "heating-side circulation water path."

Like the control device 150 of the first embodiment, the control device 150 of this embodiment is configured to be able to perform reheating operation, heat retention operation, and fine bubble generation operation. That is, the control device 150 of this embodiment is configured to be able to perform heat retention processing (Figure 6), circulation processing (Figure 7), first heating processing (Figure 8), fine bubble generation processing (Figure 9), and second heating processing (Figure 10). The control device 150 of this embodiment heats the water in the bathtub 130 by controlling the operation of the heat exchange unit 312 instead of the first heat source unit 12 (see Figure 1) of the first embodiment in the reheating operation, heat retention processing (see S16 of Figure 6), first heating processing (see S122 and S124 of Figure 8), and second heating processing (see S212, S214, and S232 of Figure 10). Specifically, the control device 150 adjusts the aperture of the flow control valve 334 to a predetermined aperture, drives the second circulation pump 328, and operates the second heat source unit 322 so that the temperature of the water flowing through the heating-side circulation water channel becomes a predetermined circulation heating temperature (e.g., 80°C). As a result, the control device 150 causes heat exchange between the water passing through the first heat exchange channel 330 and the water passing through the second heat exchange channel 332 in the heat exchange unit 312. In this embodiment, the control device 150 adjusts the heating amount of the heat exchange unit 312 by controlling the aperture of the flow control valve 334. For example, in reheating operation, the control device 150 adjusts the heating amount of the heat exchange unit 312 to the first heat source heating amount by adjusting the aperture of the flow control valve 334 to fully open (i.e., 100%). In S212 of FIG. 10, the control device 150 adjusts the opening of the flow control valve 334 to 25%, thereby setting the heating amount of the heat exchange unit 312 to the fifth heat source heating amount. In S214 of FIG. 10, the control device 150 adjusts the opening of the flow control valve 334 to 50%, thereby setting the heating amount of the heat exchange unit 312 to the sixth heat source heating amount. In S16 of FIG. 6, S122 of FIG. 8, and S124 of FIG. 8, the control device 150 adjusts the opening of the flow control valve 334 so that the heating amounts of the heat exchange unit 312 are the second heat source heating amount, the third heat source heating amount, and the fourth heat source heating amount, respectively. In a modified example, the control device 150 may adjust the heating amount of the heat exchange unit 312 by changing the temperature of the water heated by the second heat source unit 322, i.e., the predetermined circulation heating temperature, or by adjusting the rotation speed of the second circulation pump 328.

11, the bath system 302 includes a first circulation water channel and a third circulation water channel, a first circulation pump 30, a heat exchange unit 312 (an example of a "heating device") provided in the first circulation water channel and the third circulation water channel for heating the water in the first circulation water channel and the third circulation water channel, a micro-bubble generator, a circulation return thermistor 22a, and a control device 150. The control device 150 is configured to drive the first circulation pump 30 and operate the heat exchange unit 312 at the first heat source heating amount to perform a reheating operation for heating the water in the bathtub 130, and a micro-bubble generation operation for driving the first circulation pump 30 and generating micro-bubbles in the bathtub 130 using the micro-bubble generator. When the bathtub water temperature during the fine-bubble generating operation falls below the first heating threshold temperature (YES in S200 of FIG. 10 ), the control device 150 operates the heat exchange unit 312 at a fifth heat-source heating amount, which is less than the first heat-source heating amount, to heat the water in the bathtub 130 (S212). With the above configuration, the fifth heat-source heating amount of the heat exchange unit 312 during the fine-bubble generating operation is less than the first heat-source heating amount of the first heat source unit 12 during the reheating operation, preventing a decrease in the amount of air dissolved in the water. This prevents a decrease in the bathtub water temperature during the fine-bubble generating operation and a decrease in the amount of fine bubbles generated by the fine-bubble generating operation. In other words, a decrease in the opacity of the water in the bathtub 130 is prevented. This maintains the bather's comfort during the fine-bubble generating operation.

Each embodiment has been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples given above.

(First Variation) In each embodiment, the bathtub 130 may be provided with a temperature sensor that detects the bathtub water temperature.

(Second Modification) In each embodiment, in S190 of FIG. 10, the control device 150 may specify, for example, the bath filling set temperature or a temperature obtained by subtracting a fifth predetermined value from the bath filling set temperature as the first heating determination temperature. In other words, the first heating determination temperature may be a temperature unrelated to the bathtub water temperature at the start of the fine bubble generation operation.

(Third Modification) In each embodiment, S210, S214, S230, and S232 in FIG. 10 can be omitted. In this modification, the control device 150 operates the first heat source unit 12 at the fifth heat source heating amount when the return path temperature is equal to or lower than the first heating determination temperature while the fine bubble generation operation process is being performed.

(Fourth Modification) In each embodiment, water may be discharged from the first outlet 134a into the bathtub 130 during the air introduction operation of the micro-bubble generation operation process. That is, the outlet from which water is discharged during the water supply operation may be the same as the outlet from which water is discharged during the air introduction operation.

(Fifth Variant) In each embodiment, the bath system 2, 302 may not be able to perform heat retention operation.

(Sixth Modification) In each embodiment, the control device 150 may execute the second heating process in FIG. 10 regardless of whether the keep-warm flag is "ON" or "OFF."

(Seventh Modification) In each embodiment, the control device 150 does not have to stop the first circulation pump 30 and the first heat source unit 12 even when the micro-bubble generating operation process (see FIG. 9) has ended. For example, in a modification of the first embodiment, the control device 150 may stop the first circulation pump 30 and the first heat source unit 12 if the return temperature becomes equal to or higher than the set temperature for filling water or the set temperature for keeping warm after the micro-bubble generating operation process (see FIG. 9) has ended.

(Eighth Modification) In each embodiment, the control device 150 may execute the fine bubble generating operation process without executing the circulation process (see FIG. 7) and the first heating process (see FIG. 8) if it receives a start command from the remote control 154 and the time since the previous fine bubble generating operation ended is less than or equal to a predetermined time. In this modification, in S190 of FIG. 10, the control device 150 specifies the return path temperature when the temperature specification time has elapsed since the start of the fine bubble generating operation as the start temperature, and specifies the temperature obtained by subtracting a fourth predetermined value (e.g., 1°C) from the specified start temperature as the first heating judgment temperature.

(Ninth Variation) While the first circulation operation (S70 in FIG. 7) is being performed, the control device 150 may keep the air control valve 102 open until the water level in the tank 52 falls below the lower limit water level. In this case, air is introduced into the tank 52 via the air introduction path 100 during the first circulation operation. In this variation, the control device 150 first performs the water supply operation during the microbubble generation operation process.

(Tenth Modification) In the above embodiment, air is introduced into the tank 52. In a modification, instead of air, a gas such as carbon dioxide, hydrogen, or oxygen may be introduced into the tank 52. In this case, it is preferable to arrange the tank filled with gas at the upstream end of the air introduction path 100.

(Eleventh Variant) The configuration for introducing air into the tank 52 is not limited to the air introduction path 100 and the air control valve 102, but may also be the air introduction path 100 and an air pump connected to the air introduction path 100, etc.

The technical elements described in this specification or drawings may exhibit technical utility either alone or in various combinations, and are not limited to the combinations set forth in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings may achieve multiple objectives simultaneously, and achieving any one of those objectives is itself technically useful.

2: Bath system 10: Heat source unit 12: First heat source device 20: Hot water supply path 22: Circulation return path 22a: Circulation return path thermistor 24: Circulation forward path 24a: Circulation forward path thermistor 26: Hot water filling valve 30: First circulation pump 32: Water flow switch 50: Air pressure dissolution unit 52: Tank 52a: Low water level electrode 52b: High water level electrode 60: Heat source return path 62: First bathtub water path 64: Tank forward path 66: Connecting passage 68: Heat source forward path 70: Second bathtub water path 74: Tank return path 80: First switching valve 82: Second switching valve 84: Check valve 86: Tank water supply valve 88: Pressure pump 100: Air introduction path 102: Air control valve 130: Bathtub 130a: Wall portion 130b : Inner surface 132 : Bathtub adapter 132a : Front surface 132b : Bottom surface 134a : First outlet port 134b : First suction port 134c : Second suction port 134d : Second outlet port 136 : First water passage 136a : First outlet passage 136b : First suction passage 138 : Second water passage 138a : Second outlet passage 138b : Second suction passage 140a : Non-return section 140b : Non-return section 140c : Non-return section 140d : Non-return section 142 : Fine bubble generating nozzle 150 : Control device 152 : Memory 154 : Remote control 200 : Water supply source 302 : Bath system 310 : Heat source unit 312 : Heat exchange unit 320 : Heat exchanger 322 : Second heat source unit 324 : Unit outward path 326 : Unit return path 328 : Second circulation pump 330 : First heat exchange path 332 : Second heat exchange path 334 : Flow control valve

Claims (3)

A circulation path for circulating water in the bathtub,
a bathtub circulation pump provided in the circulation path;
a heating device provided in the circulation path and configured to heat the water in the circulation path;
a microbubble generator that generates microbubbles in the bathtub water;
a temperature sensor capable of detecting the temperature of the bathtub water;
a control device;
The control device
a reheating operation in which the bathtub circulation pump is driven and the heating device is operated at a first heating amount to heat the water in the bathtub;
The system is configured to be able to execute a micro-bubble generating operation in which the bathtub circulation pump is driven and the micro-bubble generating device generates micro-bubbles in the bathtub water,
The control device
When a start instruction for starting the fine bubble generating operation is obtained, the bathtub water temperature at the start of the fine bubble generating operation is identified;
The temperature obtained by subtracting a specific temperature from the bathtub water temperature at the start of the fine bubble generating operation is specified as the predetermined temperature;
When the bathtub water temperature during the fine bubble generation operation falls below the predetermined temperature, the heating device is operated at a second heating amount that is less than the first heating amount to heat the bathtub water. A circulation path for circulating water in the bathtub,
a bathtub circulation pump provided in the circulation path;
a heating device provided in the circulation path and configured to heat the water in the circulation path;
a microbubble generator that generates microbubbles in the bathtub water;
a temperature sensor capable of detecting the temperature of the bathtub water;
a control device;
The control device
a reheating operation in which the bathtub circulation pump is driven and the heating device is operated at a first heating amount to heat the water in the bathtub;
The system is configured to be able to execute a micro-bubble generating operation in which the bathtub circulation pump is driven and the micro-bubble generating device generates micro-bubbles in the bathtub water,
The control device
When the bathtub water temperature during the fine bubble generating operation becomes equal to or lower than a predetermined temperature, the heating device is operated at a second heating amount that is less than the first heating amount to heat the bathtub water ;
The fine bubble generating operation is
a gas introduction operation for introducing gas into the fine bubble generator;
After the gas introduction operation, a water supply operation is performed to generate fine bubbles in the water of the bathtub using the gas introduced in the gas introduction operation.
It contains
The control device
When the bathtub water temperature during the water supply operation becomes equal to or lower than the predetermined temperature, the heating device is operated at the second heating amount;
When the bathtub water temperature during the gas introduction operation becomes equal to or lower than the predetermined temperature, the heating device is operated at a third heating amount greater than the second heating amount.
Bath equipment. The control device further
The bathtub water temperature is maintained at or above a preset temperature.
The bath device further includes:
a memory for storing either permission information indicating that execution of the heat retention operation is permitted or prohibition information indicating that execution of the heat retention operation is prohibited;
The control device
When the permission information is stored in the memory, if the bathtub water temperature during the fine bubble generating operation becomes equal to or lower than the predetermined temperature, the heating device is operated at the second heating amount,
3. The bath device according to claim 1, wherein when the prohibition information is stored in the memory, the heating device is not operated even if the bathtub water temperature during the fine bubble generation operation falls below the predetermined temperature.