Microbubble generator

Abstract

To provide a technique which can reduce an information amount related to a liquid level of a tank and can secure rapidity of determination processing related to opening / closing of a gas introduction valve.SOLUTION: A fine bubble generation device disclosed by the present invention includes a tank, a tank supply path, a pressure pump, a tank discharge path, a fine bubble generation nozzle, a tank circulation path, a tank circulation pump, a gas introduction mechanism, a liquid level electrode and a control device. The gas introduction mechanism includes a gas introduction port, a decompression part and a gas introduction valve which opens / closes the gas introduction port. The control device can execute the fine bubble generation operation of compressing and supplying liquid to the tank by driving the pressure pump and supplying liquid in which gas is pressurized and dissolved to the liquid tank from the tank. The control device supplies the gas introduced from the gas introduction port to the tank by circulating the liquid in the tank in the tank circulation path by driving the tank circulation pump during the execution of the fine bubble generation operation, and controls the opening / closing operation of the gas introduction valve on the basis of information about whether or not the liquid level of the tank detected by the liquid level electrode is equal to or greater than a prescribed liquid level.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] This specification relates to a microbubble generator.

Background Art

[0002] Patent Document 1 discloses a microbubble generator including: a tank for pressurizing and dissolving a gas in a liquid; a tank supply path for supplying the liquid to the tank; a pressure pump provided in the tank supply path; a tank discharge path for discharging the liquid in which the gas is pressurized and dissolved from the tank to a liquid tank; a microbubble generation nozzle provided in the tank discharge path for decompressing the liquid in which the gas is pressurized and dissolved to generate microbubbles; a tank circulation path provided separately from the tank discharge path for sending the liquid from an outlet connected to the tank to an inlet connected to the tank; a tank circulation pump provided in the tank circulation path; a gas introduction mechanism provided in the tank circulation path; two liquid level electrodes capable of detecting whether or not the liquid level of the tank is equal to or higher than a predetermined liquid level; and a control device. The gas introduction mechanism includes a decompression section for decompressing and passing the liquid, a gas inlet for introducing the gas by the negative pressure of the liquid in the decompression section, and a gas introduction valve for opening and closing the gas inlet. The control device can execute a microbubble generation operation of driving the pressure pump to pressurize and supply the liquid from the tank supply path to the tank and supplying the liquid in which the gas is pressurized and dissolved from the tank to the liquid tank via the tank discharge path. During the execution of the microbubble generation operation, the control device drives the tank circulation pump to circulate the liquid in the tank through the tank circulation path, thereby supplying the gas introduced from the gas inlet to the tank, and controls the opening and closing operation of the gas introduction valve based on information regarding whether or not the liquid level of the tank detected by one of the two liquid level electrodes is equal to or higher than a lower liquid level and information regarding whether or not the liquid level of the tank detected by the other of the two liquid level electrodes is equal to or higher than an upper liquid level.

Prior Art Documents

Patent Documents

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2015 - 127052 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] In a fine bubble generator, in order to ensure the rapidity of the determination process related to the opening and closing of the gas introduction valve, it may be desired to reduce the amount of information related to the liquid level of the tank. In the fine bubble generator of Patent Document 1, the control device is configured to control the opening and closing operation of the gas introduction valve based on the information related to whether the liquid level of the tank is equal to or higher than the lower liquid level and the information related to whether the liquid level of the tank is equal to or higher than the upper liquid level. In such a fine bubble generator, the amount of information related to the liquid level of the tank is relatively large, and there is a possibility of lacking the rapidity of the determination process related to the opening and closing of the gas introduction valve. In this specification, a technique capable of reducing the amount of information related to the liquid level of the tank and ensuring the rapidity of the determination process related to the opening and closing of the gas introduction valve is provided. In this specification, for a fine bubble generator provided with two liquid level electrodes, the two liquid level electrodes may be described by distinguishing them as the "lower liquid level electrode" and the "upper liquid level electrode". Here, the "lower liquid level" is a liquid level lower than the "upper liquid level". [Means for Solving the Problems]

[0005] The microbubble generator disclosed in this specification includes a tank for pressurizing and dissolving gas in a liquid, a tank supply line for supplying the liquid to the tank, a pressure pump provided in the tank supply line, a tank discharge line for discharging the liquid in which the gas is pressurized and dissolved from the tank to a liquid tank, a microbubble generation nozzle provided in the tank discharge line for decompressing the liquid in which the gas is pressurized and dissolved to generate microbubbles, a tank circulation line provided separately from the tank discharge line for sending the liquid from an outlet connected to the tank to an inlet connected to the tank, a tank circulation pump provided in the tank circulation line, a gas introduction mechanism provided in the tank circulation line, a liquid level electrode capable of detecting whether the liquid level of the tank is equal to or higher than a predetermined liquid level, and a control device. The gas introduction mechanism includes a decompression section for decompressing and passing the liquid, a gas inlet for introducing the gas by the negative pressure of the liquid in the decompression section, and a gas introduction valve for opening and closing the gas inlet. The control device is capable of executing a microbubble generation operation in which the pressure pump is driven to pressurize and supply the liquid from the tank supply line to the tank, and the liquid in which the gas is pressurized and dissolved is supplied from the tank to the liquid tank via the tank discharge line. During the execution of the microbubble generation operation, the control device drives the tank circulation pump to circulate the liquid in the tank through the tank circulation line, thereby supplying the gas introduced from the gas inlet to the tank, and controls the opening and closing operation of the gas introduction valve based on information regarding whether the liquid level of the tank detected by the liquid level electrode is equal to or higher than a predetermined liquid level.

[0006] Another microbubble generator disclosed in this specification includes a tank for pressurizing and dissolving gas in a liquid, a tank supply path for supplying the liquid to the tank, a pressurizing pump provided in the tank supply path, a tank discharge path for discharging the liquid in which the gas is pressurized and dissolved from the tank to a liquid tank, a microbubble generation nozzle provided in the tank discharge path for reducing the pressure of the liquid in which the gas is pressurized and dissolved to generate microbubbles, a tank circulation path provided separately from the tank discharge path for sending the liquid from an outlet connected to the tank to an inlet connected to the tank, a tank circulation pump provided in the tank circulation path, a gas introduction mechanism provided in the tank circulation path, a single liquid level electrode capable of detecting whether the liquid level of the tank is equal to or higher than a predetermined liquid level, and a control device. The gas introduction mechanism includes a decompression section for decompressing and passing the liquid, a gas inlet for introducing the gas by the negative pressure of the liquid in the decompression section, and a gas introduction valve for opening and closing the gas inlet. The control device is capable of executing a microbubble generation operation in which the pressurizing pump is driven to pressurize and supply the liquid from the tank supply path to the tank, and the liquid in which the gas is pressurized and dissolved is supplied from the tank to the liquid tank via the tank discharge path. During the execution of the microbubble generation operation, the control device drives the tank circulation pump to circulate the liquid in the tank through the tank circulation path, thereby supplying the gas introduced from the gas inlet to the tank, and controls the opening and closing operation of the gas introduction valve based on information regarding whether the liquid level of the tank detected by the single liquid level electrode is equal to or higher than a predetermined liquid level.

[0007] According to the above configuration, the control device is configured to control the opening and closing operation of the gas introduction valve based on information regarding whether the liquid level of the tank detected by one liquid level electrode is equal to or higher than a predetermined liquid level. Therefore, the amount of information related to the liquid level of the tank can be reduced, and the rapidity of the determination process related to the opening and closing of the gas introduction valve can be ensured.

[0008] In one or more embodiments, during the execution of the microbubble generation operation, when the liquid level electrode detects that the liquid level of the tank is lower than the predetermined liquid level while the gas introduction valve is open, the control device closes the gas introduction valve, maintains the closed state of the gas introduction valve until a first predetermined time elapses after closing the gas introduction valve, and may open the gas introduction valve after the elapse of the first predetermined time.

[0009] In the microbubble generator, there is a possibility that the liquid level electrode becomes sticky due to droplets scattered from the liquid surface of the tank adhering to the liquid level electrode. If the liquid level electrode becomes sticky, there is a risk of misdetecting the liquid level of the tank. For example, when the microbubble generator includes a lower liquid level electrode and an upper liquid level electrode, and the control device controls the opening and closing operation of the gas introduction valve so that the liquid level of the tank changes between the lower liquid level and the upper liquid level, the upper liquid level electrode is not substantially immersed in the liquid. Therefore, it is not possible to suppress the occurrence of stickiness at the upper liquid level electrode, and there is a risk of misdetecting the liquid level of the tank. According to the above configuration, during the execution of the microbubble generation operation, by frequently immersing the liquid level electrode in the liquid, the occurrence of stickiness at the liquid level electrode can be suppressed. Therefore, misdetection of the liquid level of the tank can be suppressed.

[0010] In one or more embodiments, during the execution of the microbubble generation operation, the control device specifies the elapsed time from when the closed gas introduction valve is opened until the liquid level electrode detects that the liquid level of the tank is lower than the predetermined liquid level and closes the gas introduction valve as the intake time, and when the intake time exceeds the upper limit intake time, the rotation speed of the pressure pump may be reduced when the pressure pump is driven thereafter.

[0011] When the intake time is too long, it is assumed that the amount of liquid supplied to the tank is too large or the amount of gas introduced by the gas introduction mechanism is too small. Also, the higher the rotation speed of the pressure pump, the greater the amount of liquid supplied to the tank, and the lower the rotation speed of the pressure pump, the smaller the amount of liquid supplied to the tank. According to the above configuration, when the intake time exceeds the upper limit intake time, that is, when the intake time is too long, by reducing the rotation speed of the pressure pump, the amount of liquid supplied to the tank can be decreased, and the intake time can be shortened.

[0012] In one or more embodiments, during the execution of the microbubble generation operation, the control device specifies the elapsed time from when the gas introduction valve in the closed state is opened until the liquid level electrode detects that the liquid level of the tank is lower than the predetermined liquid level and closes the gas introduction valve as the intake time. When the intake time is less than the lower limit intake time, the rotation speed of the pressure pump when driving the pressure pump thereafter may be increased.

[0013] When the intake time is too short, it is assumed that the amount of liquid supplied to the tank is too small or the amount of gas introduced by the gas introduction mechanism is too large. According to the above configuration, when the intake time is less than the lower limit intake time, that is, when the intake time is too short, by increasing the rotation speed of the pressure pump, the amount of liquid supplied to the tank can be increased, and the intake time can be extended.

[0014] In one or more embodiments, during the execution of the microbubble generation operation, the control device specifies the elapsed time from when the gas introduction valve in the closed state is opened until the liquid level electrode detects that the liquid level of the tank is lower than the predetermined liquid level and closes the gas introduction valve as the intake time. When the intake time exceeds the upper limit intake time, the rotation speed of the tank circulation pump when driving the tank circulation pump with the gas introduction valve open thereafter may be increased.

[0015] If the intake time is too long, it is assumed that the amount of liquid supplied to the tank is too large or the amount of gas introduced by the gas introduction mechanism is too small. Also, when the gas introduction valve is open, the higher the rotational speed of the tank circulation pump, the greater the amount of gas introduced by the gas introduction mechanism, and the lower the rotational speed of the tank circulation pump, the smaller the amount of gas introduced by the gas introduction mechanism. According to the above configuration, when the intake time exceeds the upper limit intake time, that is, when the intake time is too long, by increasing the rotational speed of the tank circulation pump, the amount of gas introduced by the gas introduction mechanism can be increased, and the intake time can be shortened.

[0016] In one or more embodiments, during the execution of the fine bubble generation operation, the control device determines the elapsed time from when the gas introduction valve in the closed state is opened until the liquid level electrode detects that the liquid level of the tank is lower than the predetermined liquid level and closes the gas introduction valve as the intake time. When the intake time is less than the lower limit intake time, the rotational speed of the tank circulation pump when driving the tank circulation pump with the gas introduction valve open thereafter may be reduced.

[0017] If the intake time is too short, it is assumed that the amount of liquid supplied to the tank is too small or the amount of gas introduced by the gas introduction mechanism is too large. According to the above configuration, when the intake time is less than the lower limit intake time, that is, when the intake time is too short, by reducing the rotational speed of the tank circulation pump, the amount of gas introduced by the gas introduction mechanism can be decreased, and the intake time can be extended.

[0018] In one or more embodiments, during the execution of the microbubble generation operation, the control device can determine whether a stop condition for stopping the microbubble generation operation is satisfied, and when the stop condition is satisfied, a stop process for stopping the microbubble generation operation may be executed. When the stop process is executed, the control device opens the gas introduction valve while driving the pressure pump and the tank circulation pump, and when the liquid level electrode detects that the liquid level of the tank is lower than the predetermined liquid level with the gas introduction valve open, the control device closes the gas introduction valve. After closing the gas introduction valve, the control device maintains the closed state of the gas introduction valve until a second predetermined time, which is longer than the first predetermined time, elapses. After the second predetermined time elapses, the control device may stop the pressure pump and the tank circulation pump to stop the microbubble generation operation.

[0019] According to the above configuration, the microbubble generation operation can be stopped with the liquid level electrode immersed in the liquid. Thereby, the generation of slime on the liquid level electrode can be suppressed, and the erroneous detection of the liquid level of the tank can be suppressed. Also, according to the above configuration, when stopping the microbubble generation operation, the liquid level electrode is immersed in the liquid up to a portion above the portion immersed in the liquid during normal operation. Therefore, the generation of slime on the liquid level electrode can be more appropriately suppressed.

[0020] In one or more embodiments, during the execution of the microbubble generation operation, when the liquid level electrode detects that the liquid level of the tank is equal to or higher than the predetermined liquid level with the gas introduction valve closed, the control device opens the gas introduction valve, maintains the open state of the gas introduction valve until a third predetermined time elapses after opening the gas introduction valve, and closes the gas introduction valve after the third predetermined time elapses.

[0021] For example, when the fine bubble generator includes a lower liquid level electrode and an upper liquid level electrode, and the control device controls the opening and closing operation of the gas introduction valve so that the liquid level in the tank changes between the lower liquid level and the upper liquid level, it is necessary to make the length of the lower liquid level electrode relatively long. In this case, it may lead to an increase in the weight of the entire device. According to the above configuration, the length of the liquid level electrode can be made relatively short. Therefore, the weight of the entire device can be reduced.

[0022] In one or more embodiments, the liquid may be water. The liquid tank may be a bathtub used by a user for bathing.

[0023] According to the above configuration, in a fine bubble generator that generates fine bubbles in the water of a bathtub used by a user, the amount of information related to the water level in the tank can be reduced, and the rapidity of the determination process related to the opening and closing of the gas introduction valve can be ensured.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0025] (Example 1) As shown in FIG. 1, the hot water device 2 of this example includes a heat source unit 10, an air pressurization and dissolution unit 50, a bathtub adapter 132, and a control device 150. The hot water device 2 can heat the water supplied from a water supply source 200 such as a water supply and supply the heated water to a faucet 250 installed in a kitchen or the like or a bathtub 130 installed in a bathroom at a desired temperature. Further, the hot water device 2 can generate fine bubbles in the water of the bathtub 130 used by the user for bathing.

[0026] (Configuration of the heat source unit 10) The heat source unit 10 includes a first heat source machine 12, a second heat source machine 14, a water supply path 16, a hot water outlet path 18, a bypass path 20, a bypass servo 22, a pouring path 24, a pouring valve 26, a water amount sensor 28, a circulation forward path 30, a circulation return path 32, a bathtub circulation pump 34, and a water flow switch 36.

[0027] The upstream end of the water supply path 16 is connected to the water supply source 200, and the downstream end of the water supply path 16 is connected to the first heat source machine 12. Further, the upstream end of the hot water outlet path 18 is connected to the first heat source machine 12, and the downstream end of the hot water outlet path 18 is connected to the faucet 250. The first heat source machine 12 is, for example, a combustion heat source machine that heats water by combustion of gas. The first heat source machine 12 heats the water flowing in from the water supply path 16 and sends out the heated water to the hot water outlet path 18.

[0028] The upstream end of the bypass passage 20 is connected to the water supply passage 16, and the downstream end of the bypass passage 20 is connected to the hot water outlet passage 18. The bypass servo 22 is provided at the location where the bypass passage 20 is connected to the water supply passage 16. By adjusting the opening degree of the built-in valve body, the bypass servo 22 can adjust the ratio of the flow rate of water flowing from the water supply passage 16 through the first heat source machine 12 to the hot water outlet passage 18 and the flow rate of water flowing from the water supply passage 16 through the bypass passage 20 to the hot water outlet passage 18. By adjusting the opening degree of the bypass servo 22, hot water flowing in from the first heat source machine 12 and cold water flowing in from the bypass passage 20 are mixed at a desired ratio in the hot water outlet passage 18 on the downstream side of the connection location of the bypass passage 20, and water adjusted to a desired temperature is supplied. A hot water outlet thermistor 18a for detecting the temperature of the water in the hot water outlet passage 18 is provided in the hot water outlet passage 18 on the downstream side of the connection location of the bypass passage 20.

[0029] The upstream end of the pouring passage 24 is connected to the hot water outlet passage 18 on the downstream side of the connection location of the bypass passage 20, and the downstream end of the pouring passage 24 is connected to the circulation return passage 32. The pouring valve 26 is provided in the pouring passage 24 and opens and closes the pouring passage 24. The pouring valve 26 is normally in a closed state. The water volume sensor 28 is provided in the pouring passage 24 and detects the water volume of the water flowing through the pouring passage 24.

[0030] The upstream end of the circulation return passage 32 is connected to the heat source return passage 60 (details will be described later) of the air pressurization dissolution unit 50, and the downstream end of the circulation return passage 32 is connected to the second heat source machine 14. Also, the upstream end of the circulation forward passage 30 is connected to the second heat source machine 14, and the downstream end of the circulation forward passage 30 is connected to the heat source forward passage 68 (details will be described later) of the air pressurization dissolution unit 50. The second heat source machine 14 is, for example, a combustion heat source machine that heats water by gas combustion. The second heat source machine 14 heats the water flowing in from the circulation return passage 32 and sends out the heated water to the circulation forward passage 30. A circulation return thermistor 32a for detecting the temperature of the water in the circulation return passage 32 is provided near the upstream end of the circulation return passage 32. A circulation forward thermistor 30a for detecting the temperature of the water in the circulation forward passage 30 is provided near the downstream end of the circulation forward passage 30.

[0031] The bathtub circulation pump 34 is provided in the circulation return path 32 on the downstream side of the connection point of the hot water injection path 24, and sends the water in the circulation return path 32 toward the second heat source machine 14. The water flow switch 36 is provided between the bathtub circulation pump 34 and the second heat source machine 14 in the circulation return path 32, and detects whether water is flowing in the circulation return path 32.

[0032] (Configuration of the air pressurization and dissolution unit 50) The air pressurization and dissolution unit 50 includes a tank 52, a heat source return path 60, a heat source forward path 68, a tank return path 74, a tank forward path 64, a communication path 66, a first three-way valve 80, a second three-way valve 82, a check valve 84, a tank water supply valve 86, a first pressurization pump 88, a second pressurization pump 90, a tank circulation path 92, a tank circulation pump 94, and a gas introduction mechanism 96.

[0033] The tank 52 is used to pressurize and dissolve air in water to generate air-dissolved water. The tank 52 can store water inside. Inside the tank 52, a water level electrode 54 for detecting the water level in the tank 52 and a ground electrode (not shown) are installed. When the water level electrode 54 contacts the water surface of the water stored in the tank 52, a current flows between the water level electrode 54 and the ground electrode, and an ON signal is output to the control device 150. That is, the water level electrode 54 is configured to be able to detect whether the water level in the tank 52 is equal to or higher than a predetermined water level. Hereinafter, the water level in the tank 52 detected by the water level electrode 54 may be referred to as the "boundary water level".

[0034] One end of the heat source return path 60 is connected to the communication path 66, and the other end of the heat source return path 60 is connected to the circulation return path 32 of the heat source unit 10. The communication path 66 connects the first three-way valve 80 and the second three-way valve 82. The first three-way valve 80 is connected to the communication path 66, the first bathtub water path 62, and the tank forward path 64. The first three-way valve 80 can switch between a first communication state (see Fig. 6) in which the tank forward path 64 and the first bathtub water path 62 are in communication, a second communication state (see Fig. 1) in which the tank forward path 64 and the communication path 66 are in communication, and a third communication state (see Figs. 4 and 5) in which the first bathtub water path 62, the tank forward path 64, and the communication path 66 are in communication. The upstream end of the tank forward path 64 is connected to the lower part of the tank 52, and the downstream end of the tank forward path 64 is connected to the first three-way valve 80. A check valve 84 that allows water to flow from the tank 52 toward the first three-way valve 80 and prohibits water from flowing from the first three-way valve 80 toward the tank 52 is provided in the tank forward path 64. One end of the first bathtub water path 62 is connected to the first three-way valve 80, and the other end of the first bathtub water path 62 is connected to the bathtub adapter 132.

[0035] One end of the heat source forward path 68 is connected to the circulation forward path 30 of the heat source unit 10, and the other end of the heat source forward path 68 is connected to the second three-way valve 82. The second three-way valve 82 is connected to the communication path 66, the heat source forward path 68, and the second bathtub water path 70. The second three-way valve 82 can switch between a fourth communication state (see Fig. 6) in which the second bathtub water path 70 and the communication path 66 are in communication and a fifth communication state (see Figs. 1, 4, and 5) in which the heat source forward path 68 and the second bathtub water path 70 are in communication. One end of the second bathtub water path 70 is connected to the second three-way valve 82, and the other end of the second bathtub water path 70 is connected to the bathtub adapter 132.

[0036] The upstream end of the tank return path 74 is connected to the heat source forward path 68, and the downstream end of the tank return path 74 is connected to the tank 52 via the water supply port 74a. The tank water supply valve 86 is provided in the tank return path 74 and opens and closes the tank return path 74. The tank water supply valve 86 is normally in a closed state. The first pressurizing pump 88 and the second pressurizing pump 90 are provided in the tank return path 74 between the tank water supply valve 86 and the tank 52. The first pressurizing pump 88 and the second pressurizing pump 90 pressurize the water in the tank return path 74 and send it out toward the tank 52. In the tank return path 74, the first pressurizing pump 88 is arranged upstream of the second pressurizing pump 90.

[0037] The upstream end of the tank circulation path 92 (hereinafter also referred to as the outlet 92a) is connected to the bottom of the tank 52, and the downstream end of the tank circulation path 92 is connected to the tank return path 74 downstream of the second pressurizing pump 90. The water level at the location where the outlet 92a of the tank circulation path 92 is connected to the tank 52 is lower than the boundary water level. The tank circulation pump 94 is provided in the tank circulation path 92. The tank circulation pump 94 sucks the water in the tank 52 into the tank circulation path 92 through the outlet 92a, and discharges the water in the tank circulation path 92 into the tank 52 through the water supply port 74a at the downstream end of the tank return path 74.

[0038] The gas introduction mechanism 96 is provided in the tank circulation path 92 on the upstream side of the tank circulation pump 94. The gas introduction mechanism 96 includes a water inlet pipe 98, a water outlet pipe 100, a venturi pipe 102, a gas introduction path 104, and a gas introduction valve 106. Water flows into the water inlet pipe 98 from the upstream side of the tank circulation path 92. The water outlet pipe 100 discharges water to the downstream side of the tank circulation path 92. The venturi pipe 102 connects the water inlet pipe 98 and the water outlet pipe 100. The diameter of the venturi pipe 102 is smaller than the diameters of the water inlet pipe 98 and the water outlet pipe 100. The water flowing through the gas introduction mechanism 96 is depressurized to a pressure lower than the atmospheric pressure when flowing from the water inlet pipe 98 to the venturi pipe 102, and is pressurized back to the original pressure when flowing from the venturi pipe 102 to the water outlet pipe 100. The upstream end of the gas introduction path 104 (hereinafter also referred to as the gas inlet 104a) is open to the atmosphere, and the downstream end is connected to the venturi pipe 102. The gas introduction valve 106 is provided in the gas introduction path 104 and opens and closes the gas introduction path 104. When the gas introduction valve 106 is open when water is flowing through the gas introduction mechanism 96, air is inhaled from the gas inlet 104a into the gas introduction path 104, and the air is mixed with the water flowing through the venturi pipe 102. The air introduced through the gas introduction path 104 flows into the tank 52 together with the water flowing through the tank circulation path 92. The gas introduction valve 106 is normally in a closed state.

[0039] (Configuration of the bathtub adapter 132) Next, with reference to FIGS. 2 and 3, the bathtub adapter 132 provided on the wall portion 130a of the bathtub 130 will be described. FIG. 2 shows the flow of water in the bathtub adapter 132 when water is flowing from the first bathtub water path 62 toward the bathtub 130 and water is flowing from the bathtub 130 toward the second bathtub water path 70 (for example, the state in FIG. 6). FIG. 3 shows the flow of water in the bathtub adapter 132 when water is flowing from the bathtub 130 toward the first bathtub water path 62 and water is flowing from the second bathtub water path 70 toward the bathtub 130 (for example, the state in FIG. 5).

[0040] The bathtub adapter 132 includes a first water passage 136 and a second water passage 138. The first water passage 136 communicates with the first bathtub water passage 62, and the second water passage 138 communicates with 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 communicates with a first discharge port 134a provided on the front surface 132a of the bathtub adapter 132. The water discharged from the first discharge port 134a into the bathtub 130 is discharged in front of the wall portion 130a of the bathtub 130, that is, in a direction perpendicular to the wall portion 130a of the bathtub 130. The first discharge passage 136a is provided with a check valve 140a for preventing the flow of water from the bathtub 130 toward the first bathtub water passage 62 and a fine bubble generation nozzle 142 disposed upstream of the check valve 140a (on the side of the first bathtub water passage 62). The fine bubble generation nozzle 142 reduces the pressure of the water passing through the fine bubble generation nozzle 142. The first suction passage 136b communicates with a first suction port 134b provided on the front surface 132a of the bathtub adapter 132. The first suction passage 136b is provided with a check valve 140b for preventing the flow of water from the first bathtub water passage 62 toward the bathtub 130.

[0041] The second water passage 138 branches into a second discharge passage 138a and a second suction passage 138b. The second suction passage 138b communicates with 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 for preventing the flow of water from the second bathtub water passage 70 toward the bathtub 130. The second discharge passage 138a communicates with a second discharge port 134d provided on the lower surface 132b of the bathtub adapter 132. The water discharged from the second discharge port 134d is discharged downward, that is, in a direction parallel to the wall portion 130a of the bathtub 130. The second discharge passage 138a is provided with a check valve 140d for preventing the flow of water from the bathtub 130 toward the second bathtub water passage 70.

[0042] (Configuration of the control device 150) The control device 150 shown in Fig. 1 controls the operations of the components of the heat source unit 10 and the air pressurization dissolution unit 50. The control device 150 is configured to be communicable with a remote controller 154 operable by a user. The control device 150 includes a memory 152 and can store various settings such as the set temperature and set water volume in the water heating operation input by the user, and the set temperature in the afterburning operation. The user can instruct the start and end of the water heating operation, afterburning operation, and microbubble generation operation, which will be described later, via the remote controller 154.

[0043] (Water heating operation) The hot water filling operation starts when the user instructs the start of the hot water filling operation on the remote controller 154. Alternatively, the hot water filling operation may start when the user sets the start time of the hot water filling operation on the remote controller 154 and the control device 150 determines that the start time of the hot water filling operation has arrived. When starting the hot water filling operation, the control device 150 sets the first three-way valve 80 and the second three-way valve 82 to the third communication state and the fifth communication state, respectively (see FIGS. 4 and 5). When the hot water filling operation is started, the control device 150 opens the hot water filling valve 26 and starts heating by the first heat source machine 12. As a result, as shown in FIG. 4, the water temperature-adjusted to the set temperature flows from the hot water outlet passage 18 into the circulation return passage 32 via the hot water pouring passage 24. The water flowing into the circulation return passage 32 branches into a flow toward the upstream side (i.e., the heat source return passage 60) and a flow toward the downstream side (i.e., the second heat source machine 14). The water flowing from the circulation return passage 32 into the heat source return passage 60 flows into the bathtub 130 via the communication passage 66, the first three-way valve 80, the first bathtub water passage 62, and the bathtub adapter 132. The water flowing from the circulation return passage 32 into the second heat source machine 14 flows into the bathtub 130 via the circulation forward passage 30, the heat source forward passage 68, the second three-way valve 82, the second bathtub water passage 70, and the bathtub adapter 132. The control device 150 waits until the integrated water volume detected by the water volume sensor 28 reaches the set water volume in the hot water filling operation. Here, the integrated water volume means the integrated water volume detected by the water volume sensor 28 since the start of the hot water filling operation. When the integrated water volume reaches the set water volume, the control device 150 closes the hot water filling valve 26 and ends the heating of the water by the first heat source machine 12. Thereafter, the control device 150 notifies the user via the remote controller 154 that the hot water filling operation is completed and ends the hot water filling operation.

[0044] (Afterburner operation) The boost operation starts when the user instructs the start of the boost operation on the remote controller 154. Alternatively, the boost operation may start when the control device 150 determines that the temperature detected by the circulation return thermistor 32a is less than the set temperature after the first heat source unit 12 finishes heating water in the water filling operation. When starting the boost operation, the control device 150 sets the first three-way valve 80 to the third communication state and the second three-way valve 82 to the fifth communication state (see FIGS. 4 and 5). From this state, the control device 150 drives the bathtub circulation pump 34 and starts heating water by the second heat source unit 14. As a result, as shown in FIG. 5, the water in the bathtub 130 is sent to the second heat source unit 14 via the bathtub adapter 132, the first bathtub water passage 62, the first three-way valve 80, the communication passage 66, the heat source return passage 60, and the circulation return passage 32. The water heated by the second heat source unit 14 is returned to the bathtub 130 via the circulation forward passage 30, the heat source forward passage 68, the second three-way valve 82, the second bathtub water passage 70, and the bathtub adapter 132. When the temperature detected by the circulation return thermistor 32a becomes equal to or higher than the set temperature, the control device 150 stops the bathtub circulation pump 34 and ends the heating of water by the second heat source unit 14. Thereafter, the control device 150 notifies the user via the remote controller 154 that the boost operation is completed and ends the boost operation.

[0045] (Fine bubble generation operation) The fine bubble generation operation starts when the user instructs the start of the fine bubble generation operation on the remote controller 154. Also, in the hot water supply device 2 of the present embodiment, after the above-described water filling operation is completed, the fine bubble generation operation is automatically started. That is, the fine bubble generation operation is executed in conjunction with the execution of the water filling operation. When starting the fine bubble generation operation, the control device 150 sets the first three-way valve 80 and the second three-way valve 82 to the third communication state and the fifth communication state, respectively (see FIGS. 4 and 5). Also, the control device 150 opens the tank water supply valve 86. From this state, the control device 150 executes the process shown in FIG. 7.

[0046] In S2, the control device 150 drives the tank circulation pump 94. As a result, water circulates between the tank 52 and the tank circulation passage 92.

[0047] In S4, the control device 150 opens the gas introduction valve 106. As a result, air is introduced into the water flowing through the gas introduction mechanism 96 of the tank circulation path 92.

[0048]

[0047] In S6, the control device 150 starts supplying the air-dissolved water from the tank 52 to the bathtub 130. Specifically, as shown in FIG. 6, the control device 150 sets the first three-way valve 80 to the first communication state and the second three-way valve 82 to the fourth communication state, and then drives the bathtub circulation pump 34, the first pressurizing pump 88, and the second pressurizing pump 90. As a result, the water in the bathtub 130 is supplied to the tank 52 via the bathtub adapter 132, the second bathtub water path 70, the second three-way valve 82, the communication path 66, the heat source return path 60, the circulation return path 32, the second heat source unit 14, the circulation forward path 30, the heat source forward path 68, and the tank return path 74. At this time, the water pressurized by the first pressurizing pump 88 and the second pressurizing pump 90 is supplied from the tank return path 74 to the tank 52. As a result, air is pressurized and dissolved in the water inside the tank 52. Then, the water in which air is pressurized and dissolved is supplied from the tank 52 to the bathtub 130 via the tank forward path 64, the first three-way valve 80, the first bathtub water path 62, and the bathtub adapter 132. At this time, when the water in which air is pressurized and dissolved passes through the microbubble generation nozzle 142 of the first discharge path 136a of the bathtub adapter 132, it is depressurized to below atmospheric pressure, and when it is ejected into the bathtub 130, it is pressurized to atmospheric pressure, generating microbubbles in the water of the bathtub 130.

[0049] In S8, the control device 150 determines whether the water level of the tank 52 is lower than the boundary water level based on the presence or absence of the ON signal output from the water level electrode 54. In this embodiment, in the gas introduction mechanism 96, the amount of air introduced when the gas introduction valve 106 is open is larger than the amount of air in the microbubbles generated in the water of the bathtub 130. Therefore, in the state where the gas introduction valve 106 is open, the amount of air in the tank 52 increases, and the water level of the tank 52 drops. When the water level of the tank 52 is above the boundary water level (NO), the process repeats S8. When the water level of the tank 52 is lower than the boundary water level (YES), the process proceeds to S10.

[0050] In S10, the control device 150 closes the gas introduction valve 106. Thereby, the introduction of air into the water flowing through the gas introduction mechanism 96 of the tank circulation path 92 is stopped. In the state where the gas introduction valve 106 is closed, since air is not supplied to the tank 52, the amount of air in the tank 52 decreases, and the water level in the tank 52 rises. In this embodiment, even while the gas introduction valve 106 is closed, the driving of the tank circulation pump 94 continues as it is. Thereby, the flow of water in the tank 52 is promoted, and the pressure dissolution of air into the water in the tank 52 is promoted.

[0051] In S12, the control device 150 starts measuring the water level rise time using a built-in timer (not shown).

[0052] In S14, the control device 150 determines whether the water level rise time started in S12 exceeds a first predetermined time (for example, 90 seconds). When the water level rise time is equal to or less than the first predetermined time (NO), the process repeats S14. When the water level rise time exceeds the first predetermined time (YES), the process proceeds to S16.

[0053] In S16, the control device 150 ends the measurement of the water level rise time by a built-in timer (not shown).

[0054] In S18, the control device 150 opens the gas introduction valve 106. Thereby, the introduction of air into the water flowing through the gas introduction mechanism 96 of the tank circulation path 92 is restarted.

[0055] In S20, the control device 150 starts measuring the intake time using a built-in timer (not shown).

[0056] In S22, the control device 150 determines whether the water level in the tank 52 is below the boundary water level based on the presence or absence of the ON signal output from the water level electrode 54. When the water level in the tank 52 is equal to or higher than the boundary water level (NO), the process repeats S22. When the water level in the tank 52 is below the boundary water level (YES), the process proceeds to S24.

[0057] In S24, the control device 150 closes the gas introduction valve 106. Thereby, the introduction of air into the water flowing through the gas introduction mechanism 96 of the tank circulation path 92 is stopped.

[0058] In S26, the control device 150 ends the measurement of the intake time by a built-in timer (not shown). Note that the control device 150 stores the intake time at the end of the measurement in the memory 152.

[0059] In S28, the control device 150 determines whether the intake time stored in the memory 152 in S26 exceeds a predetermined upper limit intake time (for example, 120 seconds). If the intake time exceeds the upper limit intake time (YES), the process proceeds to S30. If the intake time is less than or equal to the upper limit intake time (NO), the process proceeds to S32.

[0060] In S30, the control device 150 reduces the rotational speeds of the first pressure pump 88 and the second pressure pump 90 by a predetermined value (for example, 10 Hz). Thereby, when the first pressure pump 88 and the second pressure pump 90 are driven thereafter, the amount of water supplied to the tank 52 decreases. After S30, the process proceeds to S32.

[0061] In S32, the control device 150 determines whether the intake time stored in the memory 152 in S26 is less than a predetermined lower limit intake time (for example, 60 seconds). If the intake time is less than the lower limit intake time (YES), the process proceeds to S34. If the intake time is greater than or equal to the lower limit intake time (NO), the process proceeds to S36.

[0062] In S34, the control device 150 increases the rotational speeds of the first pressure pump 88 and the second pressure pump 90 by a predetermined value (for example, 10 Hz). Thereby, when the first pressure pump 88 and the second pressure pump 90 are driven thereafter, the amount of water supplied to the tank 52 increases. After S34, the process proceeds to S36.

[0063] In S36, the control device 150 determines whether a stop condition for stopping the microbubble generation operation is satisfied. In this embodiment, the stop condition is that the operation time of the microbubble generation operation has reached the set time. The operation time of the microbubble generation operation is the elapsed time since the start of the microbubble generation operation. In the hot water supply device 2 of this embodiment, when the microbubble generation operation is executed independently without being linked to the execution of the water heating operation, the set time is set to, for example, 10 minutes. In contrast, when the microbubble generation operation is executed in conjunction with the execution of the water heating operation, the set time is set to, for example, 30 minutes. If the stop condition is not satisfied (in the case of NO), the process returns to S12. If the stop condition is satisfied (in the case of YES), the process proceeds to S38.

[0064] In S38, the control device 150 executes a stop process (see FIG. 8) for stopping the microbubble generation operation. After S38, the process of FIG. 7 ends.

[0065] As described above, in the process of S36, it has been explained that the control device 150 determines whether the stop condition is satisfied. However, the control device 150 can also determine whether the stop condition is satisfied even during the execution of the processes from S2 to S34. And, even during the execution of the processes from S2 to S34, when the control device 150 determines that the stop condition is satisfied, it is configured to abort the ongoing process and execute the process of S38 (i.e., the stop process).

[0066] (Stop process) As shown in FIG. 8, in S52, when the gas introduction valve 106 is closed, the control device 150 opens the gas introduction valve 106. As a result, the introduction of air into the water flowing through the gas introduction mechanism 96 of the tank circulation path 92 is resumed.

[0067] In S54, the control device 150 determines whether the water level in the tank 52 is below the boundary water level based on the presence or absence of the ON signal output from the water level electrode 54. When the water level in the tank 52 is equal to or higher than the boundary water level (NO case), the process repeats S54. When the water level in the tank 52 is below the boundary water level (YES case), the process proceeds to S56.

[0068] In S56, the control device 150 closes the gas introduction valve 106. As a result, the introduction of air into the water flowing through the gas introduction mechanism 96 in the tank circulation path 92 is stopped.

[0069] In S58, the control device 150 starts measuring the water level rise time using a built-in timer (not shown).

[0070] In S60, the control device 150 determines whether the water level rise time started in S58 exceeds a second predetermined time (for example, 180 seconds), which is longer than the first predetermined time. When the water level rise time is equal to or less than the second predetermined time (NO case), the process repeats S60. When the water level rise time exceeds the second predetermined time (YES case), the process proceeds to S62.

[0071] In S62, the control device 150 ends the measurement of the water level rise time by the built-in timer (not shown).

[0072] In S64, the control device 150 stops the bathtub circulation pump 34, the first pressurizing pump 88, and the second pressurizing pump 90, and ends the supply of air-dissolved water from the tank 52 to the bathtub 130.

[0073] In S66, the control device 150 stops the tank circulation pump 94. As a result, the circulation of water between the tank 52 and the tank circulation path 92 ends. After S66, the process in FIG. 8 ends.

[0074] In this way, in the stop process, the control device 150 can stop the fine bubble generation operation with the water level electrode 54 immersed in water. At this time, since the water level in the tank 52 at the time of ending the process of FIG. 8 is higher than the water level in the tank 52 at the time when the gas introduction valve 106 is opened at S18 in FIG. 7, the water level electrode 54 is immersed in water up to a portion above the portion immersed in water during normal operation. Thereby, the generation of slime on the water level electrode 54 can be appropriately suppressed.

[0075] (Example 2) The hot water device 2 of this embodiment has substantially the same configuration as the hot water device 2 of the first embodiment. In the hot water device 2 of this embodiment, when executing the fine bubble generation operation, instead of the control device 150 executing the process shown in FIG. 7, the process shown in FIG. 9 is executed. Below, regarding the process shown in FIG. 9, the differences from the process shown in FIG. 7 will be described.

[0076] In the process shown in FIG. 9, when the intake time stored in the memory 152 at S26 exceeds the upper limit intake time (YES at S28), the process proceeds to S70. At S70, the control device 150 increases the rotation speed of the tank circulation pump 94 by a predetermined value (for example, 10 Hz). As a result, when the tank circulation pump 94 is driven with the gas introduction valve 106 open thereafter, the amount of air introduced by the gas introduction mechanism 96 increases. After S70, the process proceeds to S32.

[0077] On the other hand, when the intake time stored in the memory 152 at S26 is less than the lower limit intake time (YES at S32), the process proceeds to S72. At S72, the control device 150 reduces the rotation speed of the tank circulation pump 94 by a predetermined value (for example, 10 Hz). As a result, when the tank circulation pump 94 is driven with the gas introduction valve 106 open thereafter, the amount of air introduced by the gas introduction mechanism 96 decreases. After S72, the process proceeds to S36.

[0078] In S70 of the process shown in FIG. 9, although the control device 150 increases the rotation speed of the tank circulation pump 94 when the gas introduction valve 106 is subsequently opened and the tank circulation pump 94 is driven, it may be configured not to increase the rotation speed of the tank circulation pump 94 when the gas introduction valve 106 is subsequently closed and the tank circulation pump 94 is driven. Similarly, in S72 of the process shown in FIG. 9, although the control device 150 reduces the rotation speed of the tank circulation pump 94 when the gas introduction valve 106 is subsequently opened and the tank circulation pump 94 is driven, it may be configured not to reduce the rotation speed of the tank circulation pump 94 when the gas introduction valve 106 is subsequently closed and the tank circulation pump 94 is driven.

[0079] (Example 3) The hot water device 2 of this embodiment has substantially the same configuration as the hot water device 2 of Example 1. In the hot water device 2 of this embodiment, when performing the fine bubble generation operation, instead of executing the process shown in FIG. 7, the control device 150 executes the process shown in FIG. 10.

[0080] In S82, the control device 150 drives the tank circulation pump 94. As a result, water circulates between the tank 52 and the tank circulation path 92.

[0081] In S84, the control device 150 starts supplying the air-dissolved water from the tank 52 to the bathtub 130. At this time, the control device 150 performs the same process as S8 in FIG. 7.

[0082] In S86, the control device 150 determines whether the water level of the tank 52 is equal to or higher than the boundary water level based on the presence or absence of the ON signal output from the water level electrode 54. If the water level of the tank 52 is lower than the boundary water level (NO), the process repeats S86. If the water level of the tank 52 is equal to or higher than the boundary water level (YES), the process proceeds to S88.

[0083] In S88, the control device 150 opens the gas introduction valve 106. As a result, the introduction of air into the water flowing through the gas introduction mechanism 96 of the tank circulation path 92 is started.

[0084] In S90, the control device 150 starts measuring the water level drop time using a built-in timer (not shown).

[0085] In S92, the control device 150 determines whether the water level drop time started in S90 exceeds a third predetermined time (e.g., 90 seconds). If the water level drop time is less than or equal to the third predetermined time (NO), the process repeats S92. If the water level drop time exceeds the third predetermined time (YES), the process proceeds to S94.

[0086] In S94, the control device 150 ends the measurement of the water level drop time using a built-in timer (not shown).

[0087] In S96, the control device 150 closes the gas introduction valve 106. Thereby, the introduction of air into the water flowing through the gas introduction mechanism 96 of the tank circulation path 92 is stopped.

[0088] In S98, the control device 150 starts measuring the exhaust time using a built-in timer (not shown).

[0089] In S100, the control device 150 determines whether the water level in the tank 52 is above the boundary water level based on the presence or absence of the ON signal output from the water level electrode 54. If the water level in the tank 52 is below the boundary water level (NO), the process repeats S100. If the water level in the tank 52 is above the boundary water level (YES), the process proceeds to S102.

[0090] In S102, the control device 150 opens the gas introduction valve 106. Thereby, the introduction of air into the water flowing through the gas introduction mechanism 96 of the tank circulation path 92 is resumed.

[0091] In S104, the control device 150 ends the measurement of the exhaust time using a built-in timer (not shown). Note that the control device 150 stores the exhaust time at the end of the measurement in the memory 152.

[0092] In S106, the control device 150 determines whether the exhaust time stored in the memory 152 in S104 exceeds a predetermined upper limit exhaust time (for example, 120 seconds). If the exhaust time exceeds the upper limit exhaust time (YES), the process proceeds to S108. If the exhaust time is less than or equal to the upper limit exhaust time (NO), the process proceeds to S110.

[0093] In S108, the control device 150 increases the rotation speeds of the first pressurizing pump 88 and the second pressurizing pump 90 by a predetermined value (for example, 10 Hz). As a result, when the first pressurizing pump 88 and the second pressurizing pump 90 are driven thereafter, the amount of water supplied to the tank 52 increases. After S108, the process proceeds to S110.

[0094] In S110, the control device 150 determines whether the exhaust time stored in the memory 152 in S104 is less than a predetermined lower limit exhaust time (for example, 60 seconds). If the exhaust time is less than the lower limit exhaust time (YES), the process proceeds to S112. If the exhaust time is greater than or equal to the lower limit exhaust time (NO), the process proceeds to S114.

[0095] In S112, the control device 150 reduces the rotation speeds of the first pressurizing pump 88 and the second pressurizing pump 90 by a predetermined value (for example, 10 Hz). As a result, when the first pressurizing pump 88 and the second pressurizing pump 90 are driven thereafter, the amount of water supplied to the tank 52 decreases. After S112, the process proceeds to S114.

[0096] In S114, the control device 150 determines whether a stop condition for stopping the microbubble generation operation is satisfied. If the stop condition is not satisfied (NO), the process returns to S90. If the stop condition is satisfied (YES), the process proceeds to S116.

[0097] In S116, the control device 150 executes a stop process (see FIG. 8) for stopping the microbubble generation operation. After S116, the process of FIG. 10 ends.

[0098] In the above description, it was explained that the control device 150 determines whether or not the stop condition is satisfied in the process of S114. However, the control device 150 can also determine whether or not the stop condition is satisfied even during the execution of the processes from S82 to S112. And the control device 150 is configured to abort the ongoing process and execute the process of S116 (i.e., the stop process) when it determines that the stop condition is satisfied even during the execution of the processes from S82 to S112.

[0099] In addition, in S108 of the process shown in FIG. 10, instead of increasing the rotation speeds of the first pressure pump 88 and the second pressure pump 90 by a predetermined value, the control device 150 may be configured to reduce the rotation speed of the tank circulation pump 94 by a predetermined value (for example, 10 Hz). As a result, when the tank circulation pump 94 is driven with the gas introduction valve 106 open thereafter, the amount of air introduced by the gas introduction mechanism 96 decreases. Similarly, in S112 of the process shown in FIG. 10, instead of reducing the rotation speeds of the first pressure pump 88 and the second pressure pump 90 by a predetermined value, the control device 150 may be configured to increase the rotation speed of the tank circulation pump 94 by a predetermined value (for example, 10 Hz). As a result, when the tank circulation pump 94 is driven with the gas introduction valve 106 open thereafter, the amount of air introduced by the gas introduction mechanism 96 increases.

[0100] (Modification example) In the above-described hot water device 2, air is introduced into the tank 52, but instead of air, gases such as carbon dioxide gas, hydrogen, and oxygen may be introduced into the tank 52. In this case, a gas-filled tank (not shown) filled with gas may be connected to the gas inlet 104a of the gas introduction passage 104.

[0101] In the above-described hot water supply device 2, in the water filling operation, based on the integrated water volume detected by the water volume sensor 28, the hot water supply device 2 stores water in the bathtub 130 up to the set water volume. In another embodiment, the hot water supply device 2 may be provided with a water level sensor capable of detecting the water level in the bathtub 130, for example, and in the water filling operation, based on the water level in the bathtub 130 detected by the water level sensor, the hot water supply device 2 may be configured to store water in the bathtub 130 up to the set water level.

[0102] In the above-described hot water supply device 2, the heat source unit 10 is connected to the calorifier 250, and the air pressurization dissolution unit 50 is connected to the bathtub 130. In another embodiment, the heat source unit 10 may be connected to another location for heat utilization, or the air pressurization dissolution unit 50 may be connected to another liquid tank.

[0103] In the above-described hot water supply device 2, in the tank circulation path 92, the gas introduction mechanism 96 is arranged upstream of the tank circulation pump 94. In another embodiment, in the tank circulation path 92, the gas introduction mechanism 96 may be arranged downstream of the tank circulation pump 94.

[0104] In the above-described hot water supply device 2, the downstream end of the tank circulation path 92 is connected to the tank return path 74 downstream of the second pressurization pump 90. In another embodiment, the downstream end of the tank circulation path 92 may not be connected to the tank return path 74, and may be provided separately from the tank return path 74 with respect to the tank 52.

[0105] In the above-described hot water supply device 2, only one water level electrode 54 is provided for detecting the water level in the tank 52. In another embodiment, a plurality of water level electrodes for detecting the water level in the tank 52 may be provided.

[0106] In the above-described hot water supply device 2, whether to execute the fine bubble generation operation in conjunction with the execution of the water filling operation may be switchable by the user via the remote controller 154.

[0107] In the above-described hot water supply device 2, when the intake time exceeds the upper limit intake time (YES in S28 of FIGS. 7 and 9), the control device 150 is configured to reduce the rotational speeds of the first pressurizing pump 88 and the second pressurizing pump 90 by a predetermined value (S30 in FIG. 7), or increase the rotational speed of the tank circulation pump 94 by a predetermined value (S70 in FIG. 9). In another embodiment, when the intake time exceeds the upper limit intake time, the control device 150 may be configured to reduce the rotational speeds of the first pressurizing pump 88 and the second pressurizing pump 90 by a predetermined value and increase the rotational speed of the tank circulation pump 94 by a predetermined value. In yet another embodiment, when the intake time exceeds the upper limit intake time, the control device 150 may be configured to shorten the first predetermined time in S14 of FIGS. 7 and 9 instead of correcting the rotational speeds of the first pressurizing pump 88, the second pressurizing pump 90, and the tank circulation pump 94. As a result, when it is subsequently detected that the water level of the tank 52 drops below the boundary water level and the water level of the tank 52 is raised (YES in S8), the time for raising the water level of the tank 52 (the time for repeatedly executing S14) is shortened.

[0108] In the above-described hot water device 2, when the intake time is less than the lower limit intake time (YES in S32 of FIGS. 7 and 9), the control device 150 increases the rotational speeds of the first pressurizing pump 88 and the second pressurizing pump 90 by a predetermined value (S34 in FIG. 7), or is configured to reduce the rotational speed of the tank circulation pump 94 by a predetermined value (S72 in FIG. 9). In another embodiment, when the intake time is less than the lower limit intake time, the control device 150 may be configured to increase the rotational speeds of the first pressurizing pump 88 and the second pressurizing pump 90 by a predetermined value and reduce the rotational speed of the tank circulation pump 94 by a predetermined value. In yet another embodiment, when the intake time is less than the lower limit intake time, the control device 150 may be configured to extend the first predetermined time in S14 of FIGS. 7 and 9 instead of correcting the rotational speeds of the first pressurizing pump 88, the second pressurizing pump 90, and the tank circulation pump 94. Thereby, when it is subsequently detected that the water level of the tank 52 is below the boundary water level and the water level of the tank 52 is raised (YES in S8), the time for raising the water level of the tank 52 (the time for repeatedly executing S14) is extended.

[0109] In the above-described hot water device 2, the stop condition for stopping the fine bubble generation operation is that the operation time of the fine bubble generation operation has reached the set time. In another embodiment, the stop condition may not be that the operation time of the fine bubble generation operation has reached the set time. For example, the stop condition may be that the user instructs the end of the fine bubble generation operation via the remote controller 154.

[0110] The length of the water level electrode 54 in the above-described hot water device 2 may be appropriately changed. That is, the boundary water level in the above-described hot water device 2 may be appropriately changed.

[0111] Each of the first predetermined time, the second predetermined time, the third predetermined time, the upper limit intake time, the lower limit intake time, the correction value of the rotational speeds of the first pressurizing pump 88 and the second pressurizing pump 90, the correction value of the rotational speed of the tank circulation pump 94, and the set time for stopping the fine bubble operation in the above-described hot water device 2 may be appropriately changed.

[0112] (Corresponding relationship) As described above, in one or more embodiments, the hot water device 2 (an example of a fine bubble generator) includes a tank 52 that pressurizes and dissolves air (an example of a gas) in water (an example of a liquid), a tank return path 74 (an example of a tank supply path) that supplies water to the tank 52, a first pressure pump 88 and a second pressure pump 90 (examples of pressure pumps) provided in the tank return path 74, a tank forward path 64 that discharges water with air pressurized and dissolved from the tank 52 to the bathtub 130 (an example of a liquid tank), a first bathtub water path 62, and a bathtub adapter 132 (an example of a tank discharge path). A fine bubble generation nozzle 142 is provided in the bathtub adapter 132 to generate fine bubbles by decompressing the water with air pressurized and dissolved. Separately provided from the tank forward path 64, the first bathtub water path 62, and the bathtub adapter 132, a tank circulation path 92 that sends water from an outlet 92a connected to the tank 52 to a water supply port 74a (an example of an inlet) connected to the tank 52, a tank circulation pump 94 provided in the tank circulation path 92, a gas introduction mechanism 96 provided in the tank circulation path 92, a water level electrode 54 (an example of a liquid level electrode) capable of detecting whether the water level of the tank 52 is above a boundary water level (an example of a predetermined liquid level), and a control device 150. The gas introduction mechanism 96 includes a venturi tube 102 (an example of a decompression section) that passes water under reduced pressure, a gas introduction port 104a that introduces air by the negative pressure of the water in the venturi tube 102, and a gas introduction valve 106 that opens and closes the gas introduction port 104a. The control device 150 can execute a fine bubble generation operation by driving the first pressure pump 88 and the second pressure pump 90 to pressurize and supply water from the tank return path 74 to the tank 52, and supplying water with air pressurized and dissolved from the tank 52 to the bathtub 130 via the tank forward path 64, the first bathtub water path 62, and the bathtub adapter 132. The control device 150 drives the tank circulation pump 94 to circulate the water in the tank 52 through the tank circulation path 92, thereby supplying the air introduced from the gas introduction port 104a to the tank 52, and controls the opening and closing operation of the gas introduction valve 106 based on the presence or absence of an ON signal output from the water level electrode 54 (an example of information related to whether the liquid level of the tank detected by the liquid level electrode is above a predetermined liquid level).

[0113] In one or more embodiments, the hot water device 2 (an example of a fine bubble generator) includes a tank 52 that pressurizes and dissolves air (an example of a gas) in water (an example of a liquid), a tank return path 74 (an example of a tank supply path) that supplies water to the tank 52, a first pressurizing pump 88 and a second pressurizing pump 90 (examples of pressurizing pumps) provided in the tank return path 74, a tank forward path 64 that discharges water with air pressurized and dissolved from the tank 52 to a bathtub 130 (an example of a liquid tank), a first bathtub water path 62, a bathtub adapter 132 (an example of a tank discharge path), a fine bubble generation nozzle 142 provided in the bathtub adapter 132 that depressurizes water with air pressurized and dissolved to generate fine bubbles, a tank circulation path 92 provided separately from the tank forward path 64, the first bathtub water path 62, and the bathtub adapter 132, which sends water from an outlet 92a connected to the tank 52 to a water supply port 74a (an example of an inlet) connected to the tank 52, a tank circulation pump 94 provided in the tank circulation path 92, a gas introduction mechanism 96 provided in the tank circulation path 92, a single water level electrode 54 (an example of a liquid level electrode) capable of detecting whether the water level of the tank 52 is above a boundary water level (an example of a predetermined liquid level), and a control device 150. The gas introduction mechanism 96 includes a venturi tube 102 (an example of a depressurizing section) that passes water through depressurization, a gas introduction port 104a that introduces air by the negative pressure of water in the venturi tube 102, and a gas introduction valve 106 that opens and closes the gas introduction port 104a. The control device 150 can execute a fine bubble generation operation by driving the first pressurizing pump 88 and the second pressurizing pump 90 to pressurize and supply water from the tank return path 74 to the tank 52, and supplying water with air pressurized and dissolved from the tank 52 to the bathtub 130 via the tank forward path 64, the first bathtub water path 62, and the bathtub adapter 132. The control device 150 drives the tank circulation pump 94 to circulate the water in the tank 52 through the tank circulation path 92, thereby supplying the air introduced from the gas introduction port 104a to the tank 52, and controls the opening and closing operation of the gas introduction valve 106 based on the presence or absence of an ON signal output from the single water level electrode 54 (an example of information related to whether the liquid level of the tank detected by the liquid level electrode is above a predetermined liquid level).

[0114] According to the above configuration, the control device 150 is configured to control the opening and closing operation of the gas introduction valve 106 based on the presence or absence of an ON signal output from one water level electrode 54. Therefore, the amount of information related to the water level in the tank 52 can be reduced, and the speed of the determination process related to the opening and closing of the gas introduction valve 106 can be ensured.

[0115] In one or more embodiments, during the execution of the fine bubble generation operation, when the water level electrode 54 detects that the water level in the tank 52 is lower than the boundary water level while the gas introduction valve 106 is open, the control device 150 closes the gas introduction valve 106, maintains the closed state of the gas introduction valve 106 until the first predetermined time elapses after closing the gas introduction valve 106, and opens the gas introduction valve 106 after the first predetermined time has elapsed.

[0116] In the hot water device 2, water droplets scattered from the water surface in the tank 52 may adhere to the water level electrode 54, causing a film to form on the water level electrode 54. When a film forms on the water level electrode 54, there is a risk of misdetecting the water level in the tank 52. For example, when the hot water device 2 includes a lower water level electrode and an upper water level electrode, and the control device 150 controls the opening and closing operation of the gas introduction valve 106 so that the water level in the tank 52 changes between the lower water level and the upper water level, the upper water level electrode is not substantially immersed in water. Therefore, it is impossible to suppress the formation of a film on the upper water level electrode, and there is a risk of misdetecting the water level in the tank 52. According to the above configuration, during the execution of the fine bubble generation operation, by frequently immersing the water level electrode 54 in water, the formation of a film on the water level electrode 54 can be suppressed. Therefore, misdetection of the water level in the tank 52 can be suppressed.

[0117] In one or more embodiments, during the execution of the fine bubble generation operation, the control device 150 specifies the elapsed time from when the closed gas introduction valve 106 is opened until the water level electrode 54 detects that the water level in the tank 52 is lower than the boundary water level and closes the gas introduction valve 106 as the intake time. When the intake time exceeds the upper limit intake time, the rotation speeds of the first pressurizing pump 88 and the second pressurizing pump 90 are reduced when the first pressurizing pump 88 and the second pressurizing pump 90 are driven thereafter.

[0118] If the intake time is too long, it is assumed that the amount of water supplied to the tank 52 is too large or the amount of air introduced by the gas introduction mechanism 96 is too small. Also, the higher the rotation speeds of the first pressurizing pump 88 and the second pressurizing pump 90, the greater the amount of water supplied to the tank 52, and the lower the rotation speeds of the first pressurizing pump 88 and the second pressurizing pump 90, the smaller the amount of water supplied to the tank 52. According to the above configuration, when the intake time exceeds the upper limit intake time, that is, when the intake time is too long, by reducing the rotation speeds of the first pressurizing pump 88 and the second pressurizing pump 90, the amount of water supplied to the tank 52 can be decreased, and the intake time can be shortened.

[0119] In one or more embodiments, during the execution of the fine bubble generation operation, the control device 150 opens the gas introduction valve 106 that is in a closed state, and then specifies the elapsed time from when the water level in the tank 52 is detected by the water level electrode 54 to be lower than the boundary water level until the gas introduction valve 106 is closed as the intake time. When the intake time is less than the lower limit intake time, the rotation speeds of the first pressurizing pump 88 and the second pressurizing pump 90 when driving the first pressurizing pump 88 and the second pressurizing pump 90 thereafter are increased.

[0120] If the intake time is too short, it is assumed that the amount of water supplied to the tank 52 is too small or the amount of air introduced by the gas introduction mechanism 96 is too large. According to the above configuration, when the intake time is less than the lower limit intake time, that is, when the intake time is too short, by increasing the rotation speeds of the first pressurizing pump 88 and the second pressurizing pump 90, the amount of water supplied to the tank 52 can be increased, and the intake time can be extended.

[0121] In one or more embodiments, during the execution of the fine bubble generation operation, the control device 150 opens the gas introduction valve 106 that is in a closed state, and then specifies the elapsed time from when the water level in the tank 52 is detected by the water level electrode 54 to be lower than the boundary water level until the gas introduction valve 106 is closed as the intake time. When the intake time exceeds the upper limit intake time, the rotation speed of the tank circulation pump 94 is increased when the tank circulation pump 94 is driven with the gas introduction valve 106 open thereafter.

[0122] If the intake time is too long, it is assumed that the amount of water supplied to the tank 52 is too large or the amount of air introduced by the gas introduction mechanism 96 is too small. Also, when the gas introduction valve 106 is open, the higher the rotation speed of the tank circulation pump 94, the greater the amount of air introduced by the gas introduction mechanism 96, and the lower the rotation speed of the tank circulation pump 94, the smaller the amount of air introduced by the gas introduction mechanism 96. According to the above configuration, when the intake time exceeds the upper limit intake time, that is, when the intake time is too long, by increasing the rotation speed of the tank circulation pump 94, the amount of air introduced by the gas introduction mechanism 96 can be increased, and the intake time can be shortened.

[0123] In one or more embodiments, during the execution of the fine bubble generation operation, the control device 150 opens the gas introduction valve 106 that is in a closed state, and then specifies the elapsed time from when the water level in the tank 52 is detected by the water level electrode 54 to be lower than the boundary water level until the gas introduction valve 106 is closed as the intake time. When the intake time is less than the lower limit intake time, the rotation speed of the tank circulation pump 94 is reduced when the tank circulation pump 94 is driven with the gas introduction valve 106 open thereafter.

[0124] If the intake time is too short, it is assumed that the amount of water supplied to the tank 52 is too small or the amount of air introduced by the gas introduction mechanism 96 is too large. According to the above configuration, when the intake time is less than the lower limit intake time, that is, when the intake time is too short, by reducing the rotation speed of the tank circulation pump 94, the amount of air introduced by the gas introduction mechanism 96 can be decreased, and the intake time can be extended.

[0125] In one or more embodiments, during the execution of the fine bubble generation operation, the control device 150 can determine whether a stop condition for stopping the fine bubble generation operation is satisfied, and when the stop condition is satisfied, execute a stop process for stopping the fine bubble generation operation. When the stop process is executed, the control device 150 opens the gas introduction valve 106 while driving the first pressure pump 88, the second pressure pump 90, and the tank circulation pump 94. When the water level electrode 54 detects that the water level in the tank 52 is lower than the boundary water level while the gas introduction valve 106 is open, the control device 150 closes the gas introduction valve 106. After closing the gas introduction valve 106, the control device 150 maintains the closed state of the gas introduction valve 106 until a second predetermined time, which is longer than the first predetermined time, has elapsed. After the second predetermined time has elapsed, the control device 150 stops the first pressure pump 88, the second pressure pump 90, and the tank circulation pump 94 to stop the fine bubble generation operation.

[0126] According to the above configuration, the fine bubble generation operation can be stopped with the water level electrode 54 immersed in water. Thereby, the generation of scum at the water level electrode 54 can be suppressed, and the misdetection of the water level in the tank 52 can be suppressed. Further, according to the above configuration, when stopping the fine bubble generation operation, the water level electrode 54 is immersed in water up to a portion above the portion immersed in water during normal operation. Therefore, the generation of scum at the water level electrode 54 can be more appropriately suppressed.

[0127] In one or more embodiments, during the execution of the fine bubble generation operation, when the water level electrode 54 detects that the water level in the tank 52 is equal to or higher than the boundary water level with the gas introduction valve 106 closed, the control device 150 opens the gas introduction valve 106 and maintains the open state of the gas introduction valve 106 until a third predetermined time has elapsed after opening the gas introduction valve 106. After the third predetermined time has elapsed, the control device 150 closes the gas introduction valve 106.

[0128] For example, when the hot water device 2 is provided with a lower water level electrode and an upper water level electrode, and the control device 150 controls the opening and closing operation of the gas introduction valve 106 so that the water level in the tank 52 changes between the lower water level and the upper water level, it is necessary to make the length of the lower water level electrode relatively long. In this case, it may lead to an increase in the overall weight of the hot water device 2. According to the above configuration, the length of the water level electrode 54 can be made relatively short. Therefore, the overall weight of the hot water device 2 can be reduced.

[0129] In one or more embodiments, the liquid is water. The liquid tank is the bathtub 130 used by the user for bathing.

[0130] According to the above configuration, in the hot water device 2 that generates fine bubbles in the water of the bathtub 130 used by the user for bathing, the amount of information related to the water level in the tank 52 can be reduced, and the rapidity of the determination process related to the opening and closing of the gas introduction valve 106 can be ensured.

[0131] The above has described the embodiments in detail, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Also, the technology illustrated in this specification or the drawings can achieve multiple purposes simultaneously, and achieving one of these purposes itself has technical utility.

Explanation of Reference Numerals

[0132] 2: Hot water device 10: Heat source unit 12: First heat source machine 14: Second heat source machine 16: Water supply path 18: Hot water outlet path 18a: Hot water outlet temperature thermistor 20: Bypass path 22: Bypass servo 24: Pouring path 26: Valve 28: Water volume sensor 30: Circulation forward path 30a: Circulation forward path thermistor 32: Circulation return path 32a: Circulation return path thermistor 34: Bathtub circulation pump 36: Water flow switch 50: Air pressurization and dissolution unit 52: Tank 54: Water level electrode 60: Heat source return path 62: First bathtub water path 64: Tank forward path 66: Communication path 68: Heat source forward path 70: Second bathtub water path 74: Tank return path 74a: Water inlet 80: First three-way valve 82: Second three-way valve 84: Check valve 86: Tank water supply valve 88: First pressure pump 90: Second pressure pump 92: Tank circulation path 92a: Outlet 94: Tank circulation pump 96: Gas introduction mechanism 98: Water inlet pipe 100: Water outlet pipe 102: Venturi tube 104: Gas introduction path 104a: Gas inlet 106: Gas introduction valve 130: Bathtub 130a: Wall part 132: Bathtub adapter 132a: Front surface 132b: Bottom surface 134a: First discharge port 134b: First suction port 134c: Second suction port 134d: Second discharge port 136: First water passage 136a: First discharge path 136b: First suction path 138: Second water passage 138a: Second discharge path 138b: Second suction path 140a, 140b, 140c, 140d: Check valve parts 142: Microbubble generation nozzle 150: Control device 152: Memory 154: Remote control 200: Water supply source 250: Cock

Claims

1. A tank for pressurized dissolution of gas in a liquid, a tank supply line for supplying the liquid to the tank, a pressurizing pump provided in the tank supply line, a tank discharge line for discharging the liquid with the gas pressurized and dissolved therein from the tank to a liquid tank, a fine bubble generating nozzle provided in the tank discharge line for decompressing the liquid with the gas pressurized and dissolved therein to generate fine bubbles, a tank circulation line provided separately from the tank discharge line for sending the liquid from an outlet connected to the tank to an inlet connected to the tank, a tank circulation pump provided in the tank circulation line, a gas introduction mechanism provided in the tank circulation line, a liquid level electrode capable of detecting whether the liquid level of the tank is at or above a predetermined liquid level, a control device, and comprising: The gas introduction mechanism a decompression section for decompressing and passing the liquid therethrough, a gas inlet for introducing the gas by the negative pressure of the liquid in the decompression section, a gas introduction valve for opening and closing the gas inlet, and comprising: The control device is capable of executing a fine bubble generation operation of driving the pressurizing pump to pressurize and supply the liquid from the tank supply line to the tank, and supplying the liquid with the gas pressurized and dissolved therein from the tank to the liquid tank via the tank discharge line, During the execution of the fine bubble generation operation, driving the tank circulation pump to circulate the liquid in the tank through the tank circulation line, thereby supplying the gas introduced from the gas inlet to the tank, A fine bubble generating device that controls the opening and closing operation of the gas introduction valve based on information regarding whether the liquid level of the tank detected by the liquid level electrode is at or above a predetermined liquid level.

2. The control device During the execution of the fine bubble generation operation, when the liquid level electrode detects that the liquid level of the tank is lower than the predetermined liquid level while the gas introduction valve is open, closes the gas introduction valve, maintains the closed state of the gas introduction valve until a first predetermined time elapses after closing the gas introduction valve, The fine bubble generating device according to Claim 1, wherein the gas introduction valve is opened after the elapse of the first predetermined time.

3. The control device During the execution of the fine bubble generation operation, specifies, as an intake time, the elapsed time from when the closed gas introduction valve is opened until the liquid level electrode detects that the liquid level of the tank is lower than the predetermined liquid level and closes the gas introduction valve. The microbubble generator according to claim 2, wherein when the intake time exceeds the upper limit intake time, the rotational speed of the pressurizing pump when driving the pressurizing pump thereafter is reduced.

4. The control device During the execution of the microbubble generation operation, After opening the gas introduction valve in the closed state, the elapsed time from when the liquid level electrode detects that the liquid level of the tank is lower than the predetermined liquid level until closing the gas introduction valve is specified as the intake time, The microbubble generator according to claim 2 or 3, wherein when the intake time is less than the lower limit intake time, the rotational speed of the pressurizing pump when driving the pressurizing pump thereafter is increased.

5. The control device During the execution of the microbubble generation operation, After opening the gas introduction valve in the closed state, the elapsed time from when the liquid level electrode detects that the liquid level of the tank is lower than the predetermined liquid level until closing the gas introduction valve is specified as the intake time, The microbubble generator according to any one of claims 2 to 4, wherein when the intake time exceeds the upper limit intake time, the rotational speed of the tank circulation pump when driving the tank circulation pump with the gas introduction valve open thereafter is increased.

6. The control device During the execution of the microbubble generation operation, After opening the gas introduction valve in the closed state, the elapsed time from when the liquid level electrode detects that the liquid level of the tank is lower than the predetermined liquid level until closing the gas introduction valve is specified as the intake time, The microbubble generator according to any one of claims 2 to 5, wherein when the intake time is less than the lower limit intake time, the rotational speed of the tank circulation pump when driving the tank circulation pump with the gas introduction valve open thereafter is reduced.

7. The control device During the execution of the microbubble generation operation, It is possible to determine whether a stop condition for stopping the microbubble generation operation is satisfied, When the stop condition is satisfied, a stop process for stopping the microbubble generation operation is executed, When the stop process is executed, Open the gas introduction valve while driving the pressurizing pump and the tank circulation pump, When it is detected by the liquid level electrode that the liquid level of the tank is lower than the predetermined liquid level with the gas introduction valve open, close the gas introduction valve. After closing the gas introduction valve, maintain the closed state of the gas introduction valve until a second predetermined time, which is longer than the first predetermined time, has elapsed. The microbubble generator according to any one of claims 2 to 6, wherein after the elapse of the second predetermined time, the pressurizing pump and the tank circulation pump are stopped to stop the microbubble generation operation.

8. The control device During the execution of the microbubble generation operation When the liquid level electrode detects that the liquid level of the tank is equal to or higher than the predetermined liquid level while the gas introduction valve is closed, open the gas introduction valve. Maintain the open state of the gas introduction valve until a third predetermined time has elapsed after opening the gas introduction valve. The microbubble generator according to claim 1, wherein after the elapse of the third predetermined time, the gas introduction valve is closed.

9. A tank for pressurizing and dissolving gas in a liquid, A tank supply path for supplying the liquid to the tank, A pressurizing pump provided in the tank supply path, A tank discharge path for discharging the liquid in which the gas is pressurized and dissolved from the tank to a liquid tank, A microbubble generation nozzle provided in the tank discharge path for decompressing the liquid in which the gas is pressurized and dissolved to generate microbubbles, A tank circulation path provided separately from the tank discharge path for sending the liquid from an outlet connected to the tank to an inlet connected to the tank, A tank circulation pump provided in the tank circulation path, A gas introduction mechanism provided in the tank circulation path, A single liquid level electrode capable of detecting whether or not the liquid level of the tank is equal to or higher than a predetermined liquid level, Comprising a control device, The gas introduction mechanism A decompression section for decompressing and passing the liquid, A gas introduction port for introducing the gas by the negative pressure of the liquid in the decompression section, Comprising a gas introduction valve for opening and closing the gas introduction port, The control device Is capable of executing a microbubble generation operation of driving the pressurizing pump to pressurize and supply the liquid from the tank supply path to the tank, and supplying the liquid in which the gas is pressurized and dissolved from the tank to the liquid tank via the tank discharge path. During the execution of the microbubble generation operation By driving the tank circulation pump to circulate the liquid in the tank through the tank circulation path, supply the gas introduced from the gas introduction port to the tank. A fine bubble generator that controls the opening and closing operation of the gas introduction valve based on information regarding whether or not the liquid level of the tank detected by the single liquid level electrode is equal to or higher than a predetermined liquid level.

10. The liquid is water, The fine bubble generator according to any one of claims 1 to 9, wherein the liquid tank is a bathtub used by a user for bathing.

Images