Microbubble generating device

Abstract

A microbubble generating device has a control device that can implement microbubble generation operation control, which refers to driving a pressure pump to supply a liquid from a tank supply path to the tank at a pressure and supplying the liquid, in which a gas is dissolved at a pressure, from the tank to a liquid tank via a tank discharge path. The control device can implement tank circulation operation control, which refers to circulating the liquid of the tank in a tank circulation path by a tank circulation pump during the implementation of the microbubble generation operation control, and causing the pressure reduction portion of a gas introduction mechanism to generate a negative pressure. The control device is configured such that, when the microbubble generation operation control is implemented and the tank circulation operation control is implemented, in a case where both a first gas introduction valve and a second gas introduction valve are changed from a closed state to an open state, the second gas introduction valve is opened first, and then the first gas introduction valve is opened. Accordingly, the liquid of the liquid tank can be stably and continuously caused to generate microbubbles.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a fine bubble generating apparatus. Background Technology

[0002] Patent Document 1 discloses a microbubble generating device comprising: a storage tank for pressurizing and dissolving gas in a liquid; a storage tank supply path for supplying the liquid to the storage tank; a pressurizing pump disposed in the storage tank supply path; a storage tank discharge path for discharging the pressurized liquid containing the dissolved gas from the storage tank into a liquid tank; a microbubble generating nozzle disposed in the storage tank discharge path for depressurizing the pressurized liquid containing the dissolved gas to generate microbubbles; a gas introducing mechanism disposed in the storage tank; and a control device. The gas introducing mechanism comprises: a gas inlet for introducing the gas; a gas introducing path connecting the storage tank and the gas inlet; and a gas introducing valve disposed in the gas introducing path for opening and closing the gas inlet. The control device alternately performs gas introduction operation control and microbubble generation operation control. The gas introduction operation control refers to supplying liquid from the storage tank to the liquid tank when the gas introduction valve is open, thereby introducing gas into the storage tank. The microbubble generation operation control refers to driving the pressurization pump to pressurize the liquid and supply it to the storage tank from the storage tank supply path when the gas introduction valve is closed, and supplying the pressurized liquid containing the gas from the storage tank to the liquid tank from the storage tank via the storage tank discharge path.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Publication No. 2009-18118 Summary of the Invention

[0006] [The technical problem that the invention aims to solve]

[0007] In the microbubble generating device of Patent Document 1, gas introduction operation control and microbubble generation operation control cannot be performed simultaneously. Gas is supplied to the storage tank during gas introduction operation control, and gas is consumed from the storage tank during microbubble generation operation control. Therefore, gas introduction operation control and microbubble generation operation control must be performed alternately. However, during gas introduction operation control, microbubbles cannot be generated in the liquid supplied from the storage tank to the liquid tank. Therefore, the microbubbles generated in the liquid tank during microbubble generation operation control disappear during gas introduction operation control, making it difficult to continuously and stably generate microbubbles in the liquid tank. This specification provides a technique that enables the continuous and stable generation of microbubbles in the liquid tank.

[0008] [Technical means used to solve technical problems]

[0009] The microbubble generating device disclosed in this specification includes a storage tank, a storage tank supply path, a pressurizing pump, a storage tank discharge path, a microbubble generating nozzle, a storage tank circulation path, a storage tank circulation pump, a gas introduction mechanism, and a control device. The storage tank is used to pressurize and dissolve gas in a liquid; the storage tank supply path is used to supply the liquid to the storage tank; the pressurizing pump is disposed in the storage tank supply path; the storage tank discharge path is used to discharge the pressurized liquid containing the dissolved gas from the storage tank into a liquid tank; the microbubble generating nozzle is disposed in the storage tank discharge path and is used to generate microbubbles by depressurizing the pressurized liquid containing the dissolved gas; the storage tank circulation path is separate from the storage tank discharge path and is used to transport the liquid from an outlet connected to the storage tank to an inlet connected to the storage tank; the storage tank circulation pump is disposed in the storage tank circulation path; and the gas introduction mechanism is disposed in the storage tank circulation path. The gas introduction mechanism includes a pressure reducing section, a gas inlet, a gas introduction path, a first gas introduction valve, and a second gas introduction valve. The pressure reducing section depressurizes the liquid and allows it to pass through. The gas inlet introduces gas through the negative pressure of the liquid in the pressure reducing section. The gas introduction path connects the pressure reducing section and the gas inlet. The first gas introduction valve is disposed on the gas introduction path for opening and closing the gas introduction path. The second gas introduction valve is disposed on the gas introduction path between the first gas introduction valve and the gas inlet, for opening and closing the gas introduction path. The first gas introduction valve is configured to receive a force in the direction of opening when the liquid in the pressure reducing section experiences negative pressure. The second gas introduction valve is configured to receive a force in the direction of closing when the liquid in the pressure reducing section experiences negative pressure. The control device is capable of implementing microbubble generation operation control, which refers to: driving the pressurizing pump to pressurize and supply the liquid from the tank supply path to the tank, and supplying the pressurized liquid containing the gas dissolved from the tank to the liquid tank via the tank discharge path. The control device is also capable of implementing tank circulation operation control, which refers to: during the microbubble generation operation control, circulating the liquid in the tank in the tank circulation path via the tank circulation pump, thereby creating a negative pressure in the pressure reducing section of the gas introduction mechanism. The control device is configured such that, when both the first gas introduction valve and the second gas introduction valve are changed from a closed state to an open state, the second gas introduction valve is opened first, followed by the opening of the first gas introduction valve.

[0010] In the aforementioned microbubble generating device, even during the ongoing microbubble generation operation control, gas can be introduced into and supplied to the storage tank by the gas introduction mechanism through tank circulation operation control while the first and second gas introduction valves are open. Therefore, the microbubble generation operation control can be continuously implemented without interrupting it to supply gas to the storage tank. By adopting this structure, microbubbles can be stably and continuously generated from the liquid in the tank.

[0011] Furthermore, in the aforementioned microbubble generating device, a first gas inlet valve and a second gas inlet valve are provided in the gas inlet path. The second gas inlet valve is positioned between the first gas inlet valve and the gas inlet. When the negative pressure of the liquid in the pressure reducing unit acts on the first gas inlet valve, a force in the direction of opening the first gas inlet valve acts on it. When the negative pressure of the liquid in the pressure reducing unit acts on the second gas inlet valve, a force in the direction of closing the second gas inlet valve acts on it. Therefore, for example, when simultaneously implementing microbubble generating operation control and tank circulation operation control, and both the first and second gas inlet valves are changed from a closed state to an open state, if the first gas inlet valve is opened first, then when the second gas inlet valve is opened subsequently, the negative pressure of the liquid in the pressure reducing unit acts on the second gas inlet valve, raising concerns that the second gas inlet valve may not operate smoothly. As described above, when both the first gas inlet valve and the second gas inlet valve are changed from a closed state to an open state, by opening the second gas inlet valve first, the negative pressure of the liquid in the pressure reducing section can be suppressed from acting on the second gas inlet valve, thereby enabling the second gas inlet valve to operate smoothly.

[0012] In the microbubble generating device, the control device may also be configured such that, when the microbubble generating operation control is implemented and the first gas inlet valve is changed from a closed state to an open state, the flow rate of the pressurizing pump is first reduced from a first flow rate to a second flow rate that is smaller than the first flow rate, and then the first gas inlet valve is opened.

[0013] When implementing microbubble generation operation control, if the flow rate of the pressurizing pump is high, the pressure inside the storage tank increases, and the pressure of the liquid in the pressure-reducing section of the gas introduction mechanism also increases. That is, the negative pressure of the liquid in the pressure-reducing section decreases. Conversely, if the flow rate of the pressurizing pump is low, the pressure inside the storage tank decreases, and the pressure of the liquid in the pressure-reducing section of the gas introduction mechanism also decreases. That is, the negative pressure of the liquid in the pressure-reducing section increases. The negative pressure of the liquid in the pressure-reducing section exerts a force on the first gas introduction valve in the direction of opening the first gas introduction valve. Therefore, the lower the pressure of the liquid in the pressure-reducing section when the first gas introduction valve is opened, the smoother the operation of the first gas introduction valve. According to the above structure, when changing the first gas introduction valve from a closed state to an open state, the flow rate of the pressurizing pump is first reduced from the first flow rate to the second flow rate, thereby reducing the pressure of the liquid in the pressure-reducing section of the gas introduction mechanism. After that, the first gas introduction valve is opened, thus enabling the first gas introduction valve to operate smoothly. In addition, the first flow rate and the second flow rate can be set to arbitrary flow rates. For example, the first flow rate could be the flow rate of the pressurizing pump during microbubble generation operation control with the first gas inlet valve closed, and the second flow rate could be the flow rate of the pressurizing pump during both microbubble generation operation control and tank circulation operation control with the first gas inlet valve open. Alternatively, the first flow rate could also be the flow rate of the pressurizing pump when the liquid level in the tank gradually rises during the implementation of microbubble generation operation control, and the second flow rate could also be the flow rate of the pressurizing pump when the liquid level in the tank gradually decreases during the implementation of both microbubble generation operation control and tank circulation operation control.

[0014] In the microbubble generator, the control device may also be configured such that, when the tank circulation operation control is implemented and the first gas inlet valve is changed from a closed state to an open state, the flow rate of the tank circulation pump is first increased from a third flow rate to a fourth flow rate that is greater than the third flow rate, and then the first gas inlet valve is opened.

[0015] When implementing tank circulation operation control, if the flow rate of the tank circulation pump is low, the pressure of the liquid in the pressure-reducing section of the gas introduction mechanism increases. That is, the negative pressure of the liquid in the pressure-reducing section decreases. Conversely, when the flow rate of the tank circulation pump is high, the pressure of the liquid in the pressure-reducing section of the gas introduction mechanism decreases. That is, the negative pressure of the liquid in the pressure-reducing section increases. The negative pressure of the liquid in the pressure-reducing section exerts a force on the first gas introduction valve in the direction of opening the first gas introduction valve. Therefore, the lower the pressure of the liquid in the pressure-reducing section when the first gas introduction valve is opened, the smoother the operation of the first gas introduction valve. According to the above structure, when changing the first gas introduction valve from a closed state to an open state, by first increasing the flow rate of the tank circulation pump from a third flow rate to a fourth flow rate, the pressure of the liquid in the pressure-reducing section of the gas introduction mechanism is reduced, and then the first gas introduction valve is opened, thus enabling the first gas introduction valve to operate smoothly. In addition, the third and fourth flow rates can be set to arbitrary flow rates. For example, the third flow rate could be the flow rate of the tank circulation pump when the microbubble generation operation control is performed with the first gas inlet valve closed (this is the flow rate of the tank circulation pump when the tank circulation operation control is performed with the first gas inlet valve closed, and it is zero when the tank circulation operation control is not performed with the first gas inlet valve closed). The fourth flow rate could also be the flow rate of the tank circulation pump when both microbubble generation operation control and tank circulation operation control are performed with the first gas inlet valve open. Alternatively, the third flow rate could also be the flow rate of the tank circulation pump when the liquid level in the tank gradually rises during the implementation of microbubble generation operation control, and the fourth flow rate could also be the flow rate of the tank circulation pump when the liquid level in the tank gradually decreases during the implementation of both microbubble generation operation control and tank circulation operation control.

[0016] In the microbubble generator, the control device may also be configured such that, when both the first gas inlet valve and the second gas inlet valve are changed from an open state to a closed state, the first gas inlet valve is closed first, and then the second gas inlet valve is closed.

[0017] In the aforementioned microbubble generating device, a first gas inlet valve and a second gas inlet valve are provided in the gas inlet path. The second gas inlet valve is positioned between the first gas inlet valve and the gas inlet. When the negative pressure of the liquid in the pressure reducing section acts on the first gas inlet valve, a force in the direction of opening the first gas inlet valve acts on it. When the negative pressure of the liquid in the pressure reducing section acts on the second gas inlet valve, a force in the direction of closing the second gas inlet valve acts on it. Therefore, for example, when simultaneously implementing microbubble generation operation control and tank circulation operation control, if both the first and second gas inlet valves are changed from an open state to a closed state, and the second gas inlet valve is closed first, then when the second gas inlet valve is closed, the negative pressure of the liquid in the pressure reducing section acts on the second gas inlet valve, causing the valve body of the second gas inlet valve to violently impact the valve seat, potentially generating noise or damaging the second gas inlet valve. As described above, when both the first gas inlet valve and the second gas inlet valve are changed from an open state to a closed state, by closing the first gas inlet valve first, the negative pressure of the liquid in the pressure reducing section that would otherwise affect the second gas inlet valve when it is closed can be suppressed. This can suppress noise or damage to the second gas inlet valve caused by the valve body of the second gas inlet valve violently impacting the valve seat.

[0018] In the microbubble generator, the liquid can also be water, and the liquid tank can also be a bathtub used by the user for bathing.

[0019] Based on the above structure, the water in the bathtub used by the user can continuously and stably generate tiny bubbles. Attached Figure Description

[0020] Figure 1 This is a diagram schematically illustrating the structure of the hot water device 2 in an embodiment.

[0021] Figure 2 This is a cross-sectional view showing the closed state of both the first gas inlet valve 106 and the second gas inlet valve 108 in the gas inlet mechanism 96 of the hot water device 2 in the embodiment.

[0022] Figure 3 This is a cross-sectional view showing the open state of both the first gas inlet valve 106 and the second gas inlet valve 108 in the gas inlet mechanism 96 of the hot water device 2 in the embodiment.

[0023] Figure 4 This is a cross-sectional view showing the state in which the first gas inlet valve 106 is open and the second gas inlet valve 108 is closed in the gas inlet mechanism 96 of the hot water device 2 of the embodiment.

[0024] Figure 5This is a cross-sectional view showing the state in which the first gas inlet valve 106 is closed and the second gas inlet valve 108 is open in the gas inlet mechanism 96 of the hot water device 2 of the embodiment.

[0025] Figure 6 This is a schematic cross-sectional view of the bathtub adapter 132 of the hot water device 2 in an embodiment.

[0026] Figure 7 This is a flowchart of the process implemented by the control device 150 in the hot water injection operation control of the hot water device 2 in the embodiment.

[0027] Figure 8 This is a diagram schematically illustrating an example of water flow in the hot water device 2 of an embodiment.

[0028] Figure 9 This is a diagram illustrating yet another example of water flow in the hot water device 2 of the embodiment.

[0029] Figure 10 This is a flowchart of the process implemented by the control device 150 in the microbubble generation operation control of the hot water device 2 in the embodiment.

[0030] Figure 11 This is a flowchart of the air intake adjustment process implemented by the control device 150 in the microbubble generation operation control of the hot water device 2 in the embodiment.

[0031] Figure 12 This is a diagram illustrating yet another example of water flow in the hot water device 2 of the embodiment.

[0032] Figure 13 This is a diagram illustrating yet another example of water flow in the hot water device 2 of the embodiment.

[0033] Figure 14 This is a flowchart of the air intake adjustment process implemented by the control device 150 in the microbubble generation operation control of the modified hot water device 2.

[0034] Figure 15 This is a schematic diagram illustrating the structure of another modified example of a hot water device 2.

[0035] Explanation of reference numerals in the attached figures

[0036] 2: Hot water device; 10: Heat source unit; 12: First heat source unit; 14: Second heat source unit; 16: Water supply path; 18: Hot water path; 18a: Hot water temperature thermistor; 20: Bypass path; 22: Bypass servo mechanism; 24: Hot water injection path; 26: Hot water injection valve; 28: Water volume sensor; 30: Circulation path; 30a: Circulation path thermistor; 32: Circulation loop; 32a: Circulation loop thermistor; 34: Bathtub circulation pump; 36: Water flow switch; 50: Air pressurization and dissolution unit; 52: Storage tank; 52a: Low water level electrode; 52b: High water level electrode; 52c: Grounding Electrode; 60: Heat source circuit; 62: First bathtub water circuit; 64: Storage tank to circuit; 66: Connecting circuit; 68: Heat source to circuit; 70: Second bathtub water circuit; 74: Storage tank circuit; 74a: Inlet; 76: Storage tank connection path; 76a: Inlet; 80: First three-way valve; 82: Second three-way valve; 84: Check valve; 86: Storage tank water supply valve; 88: First booster pump; 90: Second booster pump; 92: Storage tank suction path; 92a: Outlet; 92b: Inlet; 94: Storage tank circulation pump; 96: Gas introduction mechanism; 98: Water inlet pipe; 100: Water outlet pipe; 102: Venturi tube; 104 104a: Gas inlet path; 104b: First gas inlet path; 104c: Third gas inlet path; 106: First gas inlet valve; 106a: Valve chamber; 106b: Valve seat; 106c: Valve body; 106d: Piston; 106e: Coil; 106f: Spring; 108: Second gas inlet valve; 108a: Valve chamber; 108b: Valve seat; 108c: Valve body; 108d: Piston; 108e: Coil; 108f: Spring; 110: Gas inlet port; 130: Bathtub; 130a: Wall; 132: Bathtub adapter; 132a: Front Surface; 132b: Lower surface; 134a: First outlet; 134b: First inlet; 134c: Second inlet; 134d: Second outlet; 136: First water path; 136a: First discharge path; 136b: First suction path; 138: Second water path; 138a: Second discharge path; 138b: Second suction path; 140a: Check valve; 140b: Check valve; 140c: Check valve; 140d: Check valve; 142: Microbubble generating nozzle; 150: Control device; 152: Memory; 154: Remote control; 200: Water supply source; 250: Faucet. Detailed Implementation

[0037] (Example)

[0038] like Figure 1As shown, the hot water device 2 of this embodiment 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 water supplied from a water source 200 such as tap water, and supply the water heated to the desired temperature to a faucet 250 installed in the kitchen or elsewhere, and to a bathtub 130 installed in the bathroom. Furthermore, the hot water device 2 can generate tiny bubbles in the water in the bathtub 130 used for bathing.

[0039] (Structure of heat source unit 10)

[0040] The heat source unit 10 includes a first heat source unit 12, a second heat source unit 14, a water supply path 16, a hot water path 18, a bypass path 20, a bypass servo mechanism 22, a hot water injection path 24, a hot water injection valve 26, a water volume sensor 28, a circulation path 30, a circulation loop 32, a bathtub circulation pump 34, and a water flow switch 36.

[0041] The upstream end of water supply path 16 is connected to water source 200, and the downstream end of water supply path 16 is connected to first heat source unit 12. Similarly, the upstream end of hot water path 18 is connected to first heat source unit 12, and the downstream end of hot water path 18 is connected to faucet 250. First heat source unit 12 is, for example, a combustion heat source unit that heats water by burning gas. First heat source unit 12 heats the water flowing into from water supply path 16 and delivers the heated water to hot water path 18.

[0042] The upstream end of the bypass path 20 is connected to the water supply path 16, and the downstream end of the bypass path 20 is connected to the hot water path 18. A bypass servo mechanism 22 is installed at the point where the bypass path 20 connects to the water supply path 16. The bypass servo mechanism 22 can adjust the ratio of the flow rate of water flowing from the water supply path 16 through the first heat source 12 to the hot water path 18, and the flow rate of water flowing from the water supply path 16 through the bypass path 20 to the hot water path 18, by adjusting the opening of its built-in valve. By adjusting the opening of the bypass servo mechanism 22, hot water flowing in from the first heat source 12 and cold water flowing in from the bypass path 20 are mixed in a desired ratio and adjusted to a desired temperature in the hot water path 18 downstream of the point where the bypass path 20 is connected. A hot water temperature thermistor 18a is installed in the hot water path 18 downstream of the point where the bypass path 20 is connected; this thermistor 18a detects the temperature of the water in the hot water path 18.

[0043] The upstream end of the hot water injection path 24 is connected to the hot water path 18, which is downstream of the bypass path 20. The downstream end of the hot water injection path 24 is connected to the circulation loop 32. A hot water injection valve 26 is installed in the hot water injection path 24 to open and close the hot water injection path 24. The hot water injection valve 26 is normally closed. A water flow sensor 28 is installed in the hot water injection path 24 to detect the amount of water flowing through the hot water injection path 24.

[0044] The upstream end of the circulation loop 32 is connected to the heat source loop 60 of the air pressurization and dissolution unit 50 (details to be described later), and the downstream end of the circulation loop 32 is connected to the second heat source 14. Additionally, the upstream end of the circulation path 30 is connected to the second heat source 14, and the downstream end of the circulation path 30 is connected to the heat source path 68 of the air pressurization and dissolution unit 50 (details to be described later). The second heat source 14 is, for example, a combustion heat source that heats water by burning gas. The second heat source 14 heats the water flowing into the circulation loop 32 and sends the heated water out to the circulation path 30. A circulation loop thermistor 32a for detecting the temperature of the water in the circulation loop 32 is provided near the upstream end of the circulation loop 32. A circulation path thermistor 30a for detecting the temperature of the water in the circulation path 30 is provided near the downstream end of the circulation path 30.

[0045] The bathtub circulation pump 34 is located downstream of the connection point of the hot water injection path 24 in the circulation loop 32, and sends water from the circulation loop 32 to the second heat source unit 14. A flow switch 36 is located in the circulation loop 32 between the bathtub circulation pump 34 and the second heat source unit 14 to detect whether water flows through the circulation loop 32.

[0046] (Structure of the air-pressurized dissolution unit 50)

[0047] The air pressurization and dissolution unit 50 includes a storage tank 52, a heat source circuit 60, a heat source destination 68, a storage tank circuit 74, a storage tank connection path 76, a storage tank destination 64, a connecting path 66, a first three-way valve 80, a second three-way valve 82, a check valve 84, a storage tank water supply valve 86, a first pressurization pump 88, a second pressurization pump 90, a storage tank suction path 92, a storage tank circulation pump 94, and a gas introduction mechanism 96.

[0048] Storage tank 52 is capable of storing water. Inside storage tank 52 are a low-level electrode 52a, a high-level electrode 52b, and a grounding electrode 52c for detecting the water level. The water level detected by the low-level electrode 52a (hereinafter referred to as the lower limit water level) is lower than the water level detected by the high-level electrode 52b (hereinafter referred to as the upper limit water level). When the low-level electrode 52a and the high-level electrode 52b are in contact with the surface of the water stored in storage tank 52, a current flows between the low-level electrode 52a, the high-level electrode 52b, and the grounding electrode 52c, thus outputting an ON signal to the control device 150. Storage tank 52 is used to pressurize and dissolve air in water to generate air-dissolved water.

[0049] One end of the heat source circuit 60 is connected to the connecting circuit 66, and the other end of the heat source circuit 60 is connected to the circulation circuit 32 of the heat source unit 10. The connecting circuit 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 connecting circuit 66, the first bathtub water circuit 62, and the storage tank outlet circuit 64. The first three-way valve 80 can switch between the first connected state, the second connected state, and the third connected state. The first connected state is the state in which the storage tank outlet circuit 64 and the first bathtub water circuit 62 are connected (see reference). Figure 12 , Figure 13 The second connection state is when the storage tank route 64 and the connecting route 66 are connected (refer to...). Figure 1 The third connected state is the state in which the water path 62 of the first bathtub, the water path 64 of the storage tank, and the connecting path 66 are connected (refer to...). Figure 8 , Figure 9 The upstream end of the storage tank outlet 64 is connected to the lower part of the storage tank 52, and the downstream end of the storage tank outlet 64 is connected to the first three-way valve 80. A one-way valve 84 is provided on the storage tank outlet 64, which allows water to flow from the storage tank 52 to the first three-way valve 80 and prevents water from flowing from the first three-way valve 80 to the storage tank 52. One end of the first bathtub water passage 62 is connected to the first three-way valve 80, and the other end of the first bathtub water passage 62 is connected to the bathtub adapter 132.

[0050] One end of the heat source path 68 is connected to the circulation path 30 of the heat source unit 10, and the other end of the heat source path 68 is connected to the second three-way valve 82. The second three-way valve 82 is connected to the connecting path 66, the heat source path 68, and the second bathtub water path 70. The second three-way valve 82 can switch between a fourth connecting state and a fifth connecting state, wherein the fourth connecting state is the state in which the second bathtub water path 70 and the connecting path 66 are connected (see reference). Figure 12 , Figure 13 The fifth connection state is the state where the heat source path 68 and the second bathtub water path 70 are connected (refer to...). Figure 1 , Figure 8 , Figure 9One end of the second bathtub water circuit 70 is connected to the second three-way valve 82, and the other end of the second bathtub water circuit 70 is connected to the bathtub adapter 132.

[0051] The upstream end of the storage tank circuit 74 is connected to the heat source path 68, and the downstream end of the storage tank circuit 74 is connected to the upstream end of the storage tank connection path 76. The downstream end of the storage tank connection path 76 (hereinafter also referred to as the inlet 76a) is connected to the top of the storage tank 52. The water level at the location where the inlet 76a of the storage tank connection path 76 is connected to the storage tank 52 is higher than the upper limit water level detected by the high water level electrode 52b. A storage tank feed valve 86 is provided in the storage tank circuit 74 to open and close the storage tank circuit 74. The storage tank feed valve 86 is normally in the closed state. The first pressurization pump 88 and the second pressurization pump 90 are located downstream of the storage tank feed valve 86 in the storage tank circuit 74. The first pressurization pump 88 and the second pressurization pump 90 pressurize the water in the storage tank circuit 74 and send it to the storage tank connection path 76. In the tank circuit 74, the first booster pump 88 is positioned upstream of the second booster pump 90. Water supplied from the tank circuit 74 to the tank connection path 76 flows into the tank 52 via the inlet 76a.

[0052] The upstream end of the tank suction path 92 (hereinafter referred to as outlet 92a) is connected to the bottom of the tank 52. The water level at the point where outlet 92a of the tank suction path 92 is connected to the tank 52 is lower than the lower limit water level detected by the low water level electrode 52a. The downstream end of the tank suction path 92 is connected to the upstream end of the tank connection path 76. A tank circulation pump 94 is installed in the tank suction path 92. The tank circulation pump 94 draws water from the tank 52 into the tank suction path 92 through outlet 92a and delivers the water from the tank suction path 92 to the tank connection path 76. The water transported from the tank suction path 92 to the tank connection path 76 flows into the tank 52 through inlet 76a.

[0053] A gas introduction mechanism 96 is located upstream of the tank circulation pump 94 in the tank suction path 92. The gas introduction mechanism 96 includes an inlet pipe 98, an outlet pipe 100, a venturi tube 102, a gas introduction path 104, a first gas introduction valve 106, and a second gas introduction valve 108. Water flows into the inlet pipe 98 from the upstream side of the tank suction path 92. The outlet pipe 100 allows water to flow out to the downstream side of the tank suction path 92. The venturi tube 102 connects the inlet pipe 98 and the outlet pipe 100. The diameter of the venturi tube 102 is smaller than the diameters of the inlet pipe 98 and the outlet pipe 100. Water flowing through the gas introduction mechanism 96 is depressurized to below atmospheric pressure as it flows from the inlet pipe 98 to the venturi tube 102, and its pressure is increased to its original pressure as it flows from the venturi tube 102 to the outlet pipe 100. The upstream end of the gas inlet path 104 (hereinafter also referred to as the gas inlet 110) is open to the atmosphere, and the downstream end is connected to the venturi tube 102. A first gas inlet valve 106 and a second gas inlet valve 108 are disposed in the gas inlet path 104 to open and close the gas inlet path 104, respectively. In the gas inlet path 104, the first gas inlet valve 106 is positioned downstream of the second gas inlet valve 108 (closer to the venturi tube 102). When water flows through the gas inlet mechanism 96 and both the first gas inlet valve 106 and the second gas inlet valve 108 are open, air is drawn into the gas inlet path 104 from the gas inlet 110, and the air mixes with the water flowing through the venturi tube 102. The air introduced by the gas inlet mechanism 96 mixes with the water flowing through the tank suction path 92 and flows into the tank 52 via the tank connection path 76.

[0054] Assuming that a gas introduction mechanism 96 as described above is provided in the tank circuit 74, air can also be introduced by the gas introduction mechanism 96 when water is supplied from the tank circuit 74 to the tank 52. However, with this structure, the pressure loss of the tank circuit 74 increases, and the pressure of the water supplied to the tank 52 via the first pressurization pump 88 and the second pressurization pump 90 decreases. Furthermore, with this structure, when the amount of air introduced into the gas introduction mechanism 96 increases, the pressure of the water supplied to the tank 52 decreases, and when the pressure of the water supplied to the tank 52 increases, the amount of air introduced into the gas introduction mechanism 96 decreases. In contrast, in this embodiment, the gas introduction mechanism 96 is provided on the tank suction path 92, which is provided independently of the tank circuit 74, thus reducing the pressure loss of the tank circuit 74. Additionally, a large amount of air can be introduced by the gas introduction mechanism 96 while water is supplied to the tank 52 from the tank circuit 74 at high pressure.

[0055] (Structure of gas introduction mechanism 96)

[0056] like Figure 2As shown, the first gas inlet valve 106 and the second gas inlet valve 108 are arranged facing each other. Furthermore, in the following description, the portion of the gas inlet path 104 between the Venturi tube 102 and the first gas inlet valve 106 is referred to as the first gas inlet path 104a, the portion between the first gas inlet valve 106 and the second gas inlet valve 108 is referred to as the second gas inlet path 104b, and the portion between the second gas inlet valve 108 and the gas inlet port 110 is referred to as the third gas inlet path 104c.

[0057] The first gas inlet valve 106 has a valve chamber 106a, a valve seat 106b, a valve body 106c, a plunger 106d, a coil 106e, and a spring 106f. The valve chamber 106a communicates with the first gas inlet path 104a and with the second gas inlet path 104b via the valve seat 106b. The valve body 106c can sit on the valve seat 106b, and when the valve body 106c sits on the valve seat 106b, the communication between the valve chamber 106a and the second gas inlet path 104b is cut off. The valve body 106c is held at the top of the plunger 106d. The plunger 106d has a core (not shown) made of magnetic material. When the coil 106e is energized, it exerts a magnetic attraction on the core of the plunger 106d. That is, when coil 106e is energized, it exerts a magnetic attraction on plunger 106d, causing valve body 106c to move away from valve seat 106b. Spring 106f exerts a loading force on plunger 106d, causing valve body 106c to sit on valve seat 106b. Figure 2 As shown, when coil 106e is not energized, spring 106f applies a loading force to plunger 106d, causing valve body 106c to sit on valve seat 106b, and the first gas inlet valve 106 closes. Figure 3 As shown, when coil 106e is energized, the magnetic attraction exerted by coil 106e on plunger 106d exceeds the loading force exerted by spring 106f on plunger 106d, thereby causing valve body 106c to move away from valve seat 106b and opening the first gas inlet valve 106. Furthermore, in the first gas inlet valve 106, when the pressure in the first gas inlet path 104a is lower than the pressure in the second gas inlet path 104b, this pressure difference exerts a force on plunger 106d, causing valve body 106c to move away from valve seat 106b.

[0058] The second gas inlet valve 108 has a valve chamber 108a, a valve seat 108b, a valve body 108c, a plunger 108d, a coil 108e, and a spring 108f. The valve chamber 108a communicates with the third gas inlet path 104c and is also connected to the second gas inlet path 104b via the valve seat 108b. The valve body 108c is seated in the valve seat 108b, and when the valve body 108c is seated in the valve seat 108b, the communication between the valve chamber 108a and the second gas inlet path 104b is cut off. The valve body 108c is held at the top of the plunger 108d. The plunger 108d has a core (not shown) made of magnetic material inside. When the coil 108e is energized, it exerts a magnetic attraction on the core of the plunger 108d. That is, when the coil 108e is energized, it exerts a magnetic attraction on the plunger 108d in a direction that moves the valve body 108c away from the valve seat 108b. The spring 108f exerts a loading force on the plunger 108d in the direction that causes the valve body 108c to sit on the valve seat 108b. For example... Figure 2 As shown, when coil 108e is not energized, spring 108f applies a loading force to plunger 108d, causing valve body 108c to sit on valve seat 108b, and the second gas inlet valve 108 to close. Figure 3 As shown, when coil 108e is energized, the magnetic attraction exerted by coil 108e on plunger 108d exceeds the loading force exerted by spring 108f on plunger 108d, causing valve body 108c to move away from valve seat 108b and opening the second gas inlet valve 108. Furthermore, when the pressure in the second gas inlet path 104b is lower than the pressure in the third gas inlet path 104c, the pressure difference exerts a force on plunger 108d in the direction that causes valve body 108c to sit on valve seat 108b.

[0059] For the closed state of both the first gas inlet valve 106 and the second gas inlet valve 108 (refer to...) Figure 2 Switch to the state where both the first gas inlet valve 106 and the second gas inlet valve 108 are open (refer to...). Figure 3 Please provide an explanation. For example... Figure 4 As shown, when the first gas inlet valve 106 is opened first, the first gas inlet path 104a and the second gas inlet path 104b are connected when the second gas inlet valve 108 is closed. In this state, when the pressure of the water flowing through the Venturi tube 102 is low (i.e., the negative pressure of the water in the Venturi tube 102 is high), the pressure in the second gas inlet path 104b becomes lower than the pressure in the third gas inlet path 104c. This pressure difference acts in the direction that causes the second gas inlet valve 108 to close. Therefore, it is difficult to open the second gas inlet valve 108 smoothly. In contrast, as... Figure 5As shown, when the second gas inlet valve 108 is opened first, the second gas inlet path 104b is disconnected from the first gas inlet path 104a. Therefore, a large pressure difference will not occur between the pressure in the second gas inlet path 104b and the pressure in the third gas inlet path 104c, allowing the second gas inlet valve 108 to open smoothly. Furthermore, in Figure 5 In the indicated state, the second gas inlet path 104b is connected to the third gas inlet path 104c. In this state, when the pressure of the water flowing through the Venturi tube 102 is low (i.e., the negative pressure of the water in the Venturi tube 102 is high), the pressure in the first gas inlet path 104a becomes lower than the pressure in the second gas inlet path 104b. This pressure difference acts in the direction of opening the first gas inlet valve 106. Therefore, the first gas inlet valve 106 can be opened smoothly.

[0060] For the open state of both the first gas inlet valve 106 and the second gas inlet valve 108 (refer to...) Figure 3 Switch to the closed state of both the first gas inlet valve 106 and the second gas inlet valve 108 (refer to...). Figure 2 Please explain the situation. For example... Figure 4 As shown, with the second gas inlet valve 108 closed first, the first gas inlet valve 106 is open, thus connecting the first gas inlet path 104a and the second gas inlet path 104b. In this state, when the pressure of the water flowing through the Venturi tube 102 is low (i.e., the negative pressure of the water in the Venturi tube 102 is high), the pressure in the second gas inlet path 104b becomes lower than the pressure in the third gas inlet path 104c. This pressure difference acts in the direction that closes the second gas inlet valve 108. Therefore, when the second gas inlet valve 108 is closed, the valve body 108c will violently impact the valve seat 108b, potentially generating noise or damaging components. In contrast, as... Figure 5 As shown, when the first gas inlet valve 106 is closed first, the second gas inlet path 104b is disconnected from the first gas inlet path 104a. Therefore, a large pressure difference will not occur between the pressure in the second gas inlet path 104b and the pressure in the third gas inlet path 104c. Thus, it is possible to suppress the valve body 108c from violently impacting the valve seat 108b when the second gas inlet valve 108 is closed, thereby suppressing noise or damage to components.

[0061] (Structure of bathtub adapter 132)

[0062] Next, refer to Figure 6 (a) and (b) in the text describe the bathtub adapter 132 installed on the wall 130a of the bathtub 130. Figure 6(a) indicates a state where water flows from the first bathtub water passage 62 to the bathtub 130, and water flows from the bathtub 130 to the second bathtub water passage 70 (e.g., Figure 12 The water flow in the bathtub adapter 132 under the condition of (state). Figure 6 (b) indicates a state where water flows from bathtub 130 to the first bathtub water passage 62, and water flows from the second bathtub water passage 70 to bathtub 130 (e.g., Figure 9 The water flow in the bathtub adapter 132 under the condition of (state).

[0063] The bathtub adapter 132 has a first water passage 136 and a second water passage 138. The first water passage 136 is connected to the first bathtub water passage 62, and the second water passage 138 is connected to the second bathtub water passage 70. The first water passage 136 branches into a first discharge path 136a and a first suction path 136b. The first discharge path 136a is connected to a first outlet 134a provided on the front surface 132a of the bathtub adapter 132. Water discharged from the first outlet 134a into the bathtub 130 is discharged in front of the wall 130a of the bathtub 130, that is, in a direction perpendicular to the wall 130a of the bathtub 130. The first discharge path 136a is provided with: a check valve 140a, which prevents water from flowing from the bathtub 130 into the first bathtub water passage 62; and a microbubble generating nozzle 142, which is positioned upstream of the check valve 140a (on the side of the first bathtub water passage 62). The microbubble generating nozzle 142 depressurizes the water passing through it. The first suction path 136b is connected to the first suction port 134b provided on the front surface 132a of the bathtub adapter 132. A backflow preventer 140b is provided on the first suction path 136b to prevent water from flowing from the first bathtub water passage 62 into the bathtub 130.

[0064] The second water passage 138 branches into a second discharge path 138a and a second suction path 138b. The second suction path 138b communicates with the second suction port 134c provided on the front surface 132a of the bathtub adapter 132. A check valve 140c is provided on the second suction path 138b to prevent water from flowing from the second bathtub water passage 70 into the bathtub 130. The second discharge path 138a communicates with the second discharge outlet 134d provided on the lower surface 132b of the bathtub adapter 132. Water discharged from the second discharge outlet 134d is discharged downwards, parallel to the wall 130a of the bathtub 130. A check valve 140d is provided on the second discharge path 138a to prevent water from flowing from the bathtub 130 into the second bathtub water passage 70.

[0065] (Structure of control device 150)

[0066] Figure 1 The control device 150 shown controls the operation of each structural element of the heat source unit 10 and the air pressurization and dissolution unit 50. The control device 150 is configured to communicate with a remote control 154 that can be operated by a user. The control device 150 has a memory 152 capable of storing various settings input by the user, such as the set temperature or set water volume in the hot water injection operation control, and the set temperature in the reheating operation control. The user can use the remote control 154 to indicate the start or end of the hot water injection operation control, the microbubble generation operation control, and the reheating operation control (described later).

[0067] (Hot water injection operation control)

[0068] The hot water injection operation control begins when the user instructs the user to start the hot water injection operation control via remote control 154. Alternatively, the hot water injection operation control may also begin when the user presets the start time of the hot water injection operation control via remote control 154, and the control device 150 determines that the start time of the hot water injection operation control has arrived. When the hot water injection operation control begins, the control device 150 sets the first three-way valve 80 and the second three-way valve 82 to the third connected state and the fifth connected state, respectively (see reference). Figure 8 , Figure 9 In this state, control device 150 performs... Figure 7 The processing is shown.

[0069] In S2, the control device 150 performs venting. Specifically, the control device 150 opens the hot water injection valve 26 and begins heating the water by the first heat source unit 12. Accordingly, as Figure 8 As shown, water regulated to a set temperature flows from hot water path 18 into circulation loop 32 via hot water injection path 24. The water flowing into circulation loop 32 flows upstream (i.e., heat source loop 60) and downstream (i.e., second heat source unit 14). Water flowing from circulation loop 32 to heat source loop 60 flows into bathtub 130 via connecting path 66, first three-way valve 80, first bathtub water path 62, and bathtub adapter 132. Conversely, water flowing from circulation loop 32 to second heat source unit 14 flows into bathtub 130 via circulation exit path 30, heat source exit path 68, second three-way valve 82, second bathtub water path 70, and bathtub adapter 132. Accordingly, the interiors of first bathtub water path 62 and second bathtub water path 70 are filled with water, and any air remaining inside these paths is expelled into bathtub 130. When the accumulated water volume detected by the water volume sensor 28 reaches a specified value (e.g., 6L), the control device 150 closes the hot water injection valve 26 and ends the heating of the first heat source unit 12, and ends the exhaust process.

[0070] In S4, the control device 150 performs residual water detection and processing in the bathtub 130. Specifically, as follows... Figure 9 As shown, the control device 150 drives the bathtub circulation pump 34 and determines whether there is remaining water in the bathtub 130 based on whether the water flow switch 36 detects water flow. If there is no remaining water in the bathtub 130 and the bathtub adapter 132 is not submerged, the water flow switch 36 will not detect water flow even if the bathtub circulation pump 34 is driven. Conversely, if there is remaining water in the bathtub 130 and the bathtub adapter 132 is submerged, the water flow switch 36 will detect water flow when the bathtub circulation pump 34 is driven. In step S4, if there is remaining water in the bathtub 130 (if yes), the process proceeds to step S6. In step S4, if there is no remaining water in the bathtub 130 (if no), the process proceeds to step S10.

[0071] In step S6, the control device 150 determines the remaining water level in the bathtub 130. Specifically, the control device 150 drives the bathtub circulation pump 34 and stores the temperature detected by the circulation loop thermistor 32a as the pre-heating temperature. After this, the control device 150 begins heating the water using the second heat source unit 14. Accordingly, as... Figure 9 As shown, the remaining water in bathtub 130 is transported to the second heat source unit 14 via bathtub adapter 132, first bathtub water passage 62, first three-way valve 80, connecting passage 66, heat source circuit 60, and circulation circuit 32. The remaining water heated by the second heat source unit 14 returns to bathtub 130 via circulation path 30, heat source path 68, second three-way valve 82, second bathtub water passage 70, and bathtub adapter 132. When the temperature detected by the circulation circuit thermistor 32a reaches or exceeds the set temperature, the control device 150 stores the temperature detected by the circulation circuit thermistor 32a as the heated temperature, stops the bathtub circulation pump 34, and ends the heating of water by the second heat source unit 14. Then, the control device 150 calculates the remaining water volume in bathtub 130 based on the temperature rise from the heated temperature to the pre-heated temperature and the cumulative heating amount in the second heat source unit 14 in S6.

[0072] In S8, the control device 150 subtracts the remaining water volume of the bathtub 130 determined in S6 from the set water volume in the hot water injection operation control, and updates the set water volume in the hot water injection operation control.

[0073] In S10, the control device 150 opens the hot water injection valve 26, initiating heating by the first heat source unit 12. Accordingly, as Figure 8As shown, water regulated to a set temperature flows from hot water path 18 into circulation loop 32 via hot water injection path 24. The water flowing into circulation loop 32 flows upstream (i.e., heat source loop 60) and downstream (i.e., second heat source unit 14). Water flowing from circulation loop 32 to heat source loop 60 flows into bathtub 130 via connecting path 66, first three-way valve 80, first bathtub water path 62, and bathtub adapter 132. Water flowing from circulation loop 32 to second heat source unit 14 flows into bathtub 130 via circulation exit path 30, heat source exit path 68, second three-way valve 82, second bathtub water path 70, and bathtub adapter 132.

[0074] In S12, the control device 150 remains on standby until the accumulated water volume detected by the water volume sensor 28 reaches the set water volume in the hot water injection operation control. Furthermore, the accumulated water volume referred to here is the sum of the accumulated water volume detected by the water volume sensor 28 during the venting process in S2 and the accumulated water volume after the start of hot water injection into the bathtub 130 in S10. When the accumulated water volume reaches the set water volume (if so), the process proceeds to S14.

[0075] In S14, the control device 150 closes the hot water injection valve 26, ending the heating of water by the first heat source 12.

[0076] In S16, the control device 150 drives the bathtub circulation pump 34 to obtain the temperature detected by the circulation loop thermistor 32a as the bathtub water temperature. Then, the control device 150 determines whether the bathtub water temperature is above the set temperature. If the bathtub water temperature has not reached the set temperature (if not), the process proceeds to S18. If the bathtub water temperature is above the set temperature (if yes), the process proceeds to S20.

[0077] In S18, the control device 150 reheats the water in the bathtub 130. Specifically, the control device 150 drives the bathtub circulation pump 34 and begins heating the water by the second heat source unit 14. Accordingly, as Figure 9 As shown, water from bathtub 130 is transported to the second heat source unit 14 via bathtub adapter 132, first bathtub water passage 62, first three-way valve 80, connecting passage 66, heat source circuit 60, and circulation circuit 32. Water heated by the second heat source unit 14 returns to bathtub 130 via circulation path 30, heat source path 68, second three-way valve 82, second bathtub water passage 70, and bathtub adapter 132. When the temperature detected by the circulation circuit thermistor 32a reaches or exceeds the set temperature, control device 150 stops bathtub circulation pump 34 and terminates water heating by the second heat source unit 14.

[0078] In step S20, the control device 150 notifies the user via remote control 154 that the hot water injection operation has ended. After step S20, Figure 7 The processing is now complete.

[0079] (Microbubble generation operation control)

[0080] The microbubble generation operation control begins when the user instructs the user to start the microbubble generation operation control using the remote control 154. Furthermore, in the hot water device 2 of this embodiment, the microbubble generation operation control also automatically begins after the aforementioned hot water injection operation control is completed. That is, the microbubble generation operation control is implemented in conjunction with the implementation of the hot water injection operation control. When the microbubble generation operation control begins, the control device 150 sets the first three-way valve 80 and the second three-way valve 82 to the third connected state and the fifth connected state, respectively (see reference). Figure 8 , Figure 9 In this state, control device 150 performs... Figure 10 The processing is shown.

[0081] In S32, the control device 150 performs a cold water relief process. Specifically, when the temperature detected by the circulation path thermistor 30a and the circulation loop thermistor 32a is below a specified temperature, the control device 150 drives the bathtub circulation pump 34 and begins heating the water by the second heat source unit 14. This cold water relief process, such as... Figure 9 As shown, the low-temperature water flows into the bathtub adapter 132 via the heat source outlet 68, the second three-way valve 82, and the second bathtub water passage 70, and is discharged into the bathtub 130 from the second outlet 134d on the lower surface 132b of the bathtub adapter 132. Therefore, even assuming the user is bathing in the bathtub 130, it is possible to prevent low-temperature water from being directly discharged into the user's body. When a predetermined time has elapsed since the start of the cold water relief treatment, the control device 150 stops the bathtub circulation pump 34 and ends the heating of the water by the second heat source 14, thus ending the cold water relief treatment.

[0082] In S34, the control device 150 opens the second gas inlet valve 108.

[0083] In S36, the control device 150 drives the tank circulation pump 94. This initiates the circulation of water between the storage tank 52, the tank suction path 92, and the tank connection path 76. Furthermore, when the tank circulation pump 94 is driven in S34, the control device 150 controls the tank circulation pump 94 to achieve a rotational speed higher than the standard speed (e.g., 120% of the standard speed).

[0084] In step S38, control device 150 opens the first gas inlet valve 106. Accordingly, air is introduced into the water flowing through the gas inlet mechanism 96 of the storage tank suction path 92.

[0085] In step S40, the control device 150 controls the tank circulation pump 94 to bring its rotational speed to a standard speed. Accordingly, the flow rate of water delivered by the tank circulation pump 94 is reduced.

[0086] In S42, control device 150 begins supplying air-dissolved water from storage tank 52 to bathtub 130. Specifically, as... Figure 12 As shown, the control device 150 sets the first three-way valve 80 to the first connected state and the second three-way valve 82 to the fourth connected state, and drives the bathtub circulation pump 34, the first pressurizing pump 88, and the second pressurizing pump 90. Accordingly, water from the bathtub 130 is supplied to the storage tank 52 via the bathtub adapter 132, the second bathtub water passage 70, the second three-way valve 82, the connecting passage 66, the heat source circuit 60, the circulation circuit 32, the second heat source motor 14, the circulation route 30, the heat source route 68, the storage tank circuit 74, and the storage tank connection path 76. At this time, water pressurized by the first pressurizing pump 88 and the second pressurizing pump 90 is supplied to the storage tank 52. Accordingly, air is pressurized and dissolved in the water inside the storage tank 52. Then, the pressurized water containing dissolved air is supplied from the storage tank 52 to the bathtub 130 via the storage tank route 64, the first three-way valve 80, the first bathtub water passage 62, and the bathtub adapter 132. At this time, the pressurized water containing dissolved air is depressurized to below atmospheric pressure when it passes through the microbubble generating nozzle 142 of the first discharge path 136a of the bathtub adapter 132. When it is sprayed into the bathtub 130, it is pressurized to atmospheric pressure, causing the water in the bathtub 130 to generate microbubbles.

[0087] exist Figure 10 In S44 shown, the control device 150 implements... Figure 11 The air intake adjustment process is shown.

[0088] exist Figure 11 In step S62, the control device 150 determines whether the water level in the storage tank 52 is below the lower limit water level based on the detection signal from the low water level electrode 52a. In this embodiment, in the gas introduction mechanism 96, when the first gas introduction valve 106 and the second gas introduction valve 108 are open, the amount of air introduced is greater than the amount of air generated by the tiny bubbles in the water of the bathtub 130. Therefore, with the first gas introduction valve 106 and the second gas introduction valve 108 open, the amount of air in the storage tank 52 gradually increases, and the water level in the storage tank 52 gradually decreases. If the water level in the storage tank 52 is below the lower limit water level (if yes), the process proceeds to step S64. If the water level in the storage tank 52 is above the lower limit water level (if no), the process proceeds to step S68.

[0089] In S64, the control device 150 closes the first gas inlet valve 106. This stops the introduction of air into the water flowing through the gas inlet mechanism 96 of the tank suction path 92. Furthermore, in this embodiment, the tank circulation pump 94 continues to operate while the first gas inlet valve 106 is closed. This promotes the flow of water within the tank 52, thereby promoting the pressurization and dissolution of air into the water within the tank 52.

[0090] In S66, the control device 150 closes the second gas inlet valve 108.

[0091] In S68, the control device 150 determines whether the water level in the storage tank 52 is above the upper limit water level based on the detection signal from the high water level electrode 52b. With the first gas inlet valve 106 and the second gas inlet valve 108 closed, no air is supplied to the storage tank 52, therefore the amount of air in the storage tank 52 gradually decreases, and the water level in the storage tank 52 gradually rises. If the water level in the storage tank 52 is above the upper limit water level (if yes), the process proceeds to S70. If the water level in the storage tank 52 is below the upper limit water level (if no), Figure 11 The processing has ended, and processing proceeds to S46 (see reference). Figure 10 ).

[0092] In S70, the control device 150 opens the second gas inlet valve 108.

[0093] In S72, control device 150 stops the second booster pump 90. Accordingly, the flow rate of water delivered by the first booster pump 88 and the second booster pump 90 is reduced.

[0094] In S74, the control device 150 controls the tank circulation pump 94 to achieve a rotational speed higher than the standard speed (e.g., 120% of the standard speed). Accordingly, the flow rate of water delivered by the tank circulation pump 94 increases.

[0095] In S76, the control device 150 opens the first gas inlet valve 106. Accordingly, air is reintroduced into the water flowing through the gas inlet mechanism 96 of the tank suction path 92.

[0096] In S78, the control device 150 controls the tank circulation pump 94 to bring its rotational speed to a standard speed. Accordingly, the flow rate of water delivered by the tank circulation pump 94 is reduced.

[0097] In S80, control device 150 restarts driving the second booster pump 90. Accordingly, the flow rate of water delivered by the first booster pump 88 and the second booster pump 90 increases. After S80, Figure 11 The processing has ended, and processing proceeds to S46 (see reference). Figure 10 ).

[0098] exist Figure 10 In step S46, the control device 150 determines whether the operation control time for the microbubble generation operation control has reached the set time. Here, the operation control time for the microbubble generation operation control is the elapsed time since the start of the microbubble generation operation control. In the hot water device 2 of this embodiment, when the microbubble generation operation control is implemented independently without linkage with the implementation of the hot water injection operation control, the set time is set to, for example, 10 minutes. In contrast, when the microbubble generation operation control is implemented in conjunction with the implementation of the hot water injection operation control, the set time is set to, for example, 30 minutes. If the operation control time has not reached the set time (if not), the process returns to S44. When the operation control time has reached the set time (if yes), the process proceeds to S48.

[0099] In S48, the control device 150 stops the bathtub circulation pump 34, the first pressurization pump 88 and the second pressurization pump 90, thereby ending the supply of air-dissolved water from the storage tank 52 to the bathtub 130.

[0100] In S50, the control device 150 closes the first gas inlet valve 106 when it is in the open state. This stops the introduction of air into the water flowing through the gas inlet mechanism 96 of the tank suction path 92.

[0101] In S52, the control device 150 closes the second gas inlet valve 108 when the second gas inlet valve 108 is in the open state.

[0102] In S54, control device 150 performs tank cleaning. Specifically, control device 150 opens hot water injection valve 26 and begins heating water by the first heat source unit 12. Accordingly, as Figure 13 As shown, water regulated to a set temperature flows from hot water path 18 into circulation loop 32 via hot water injection path 24. The water flowing into circulation loop 32 flows upstream (i.e., heat source loop 60) and downstream (i.e., second heat source unit 14). Water flowing from circulation loop 32 to heat source loop 60 flows into bathtub 130 via connecting path 66, second three-way valve 82, second bathtub water path 70, and bathtub adapter 132. Additionally, water flowing from circulation loop 32 to second heat source unit 14 flows into bathtub 130 via circulation exit path 30, heat source exit path 68, storage tank loop 74, storage tank connection path 76, storage tank 52, storage tank exit path 64, first three-way valve 80, first bathtub water path 62, and bathtub adapter 132. Accordingly, the interior of storage tank 52, storage tank suction path 92, and storage tank connection path 76 are cleaned.

[0103] In S56, control device 150 stops tank circulation pump 94. Accordingly, the circulation of water between tank 52, tank suction path 92, and tank connection path 76 ends. After S62, Figure 10 The processing is now complete.

[0104] (Reheating operation control)

[0105] Reheating operation control begins when the user instructs the user to start reheating operation control via remote control 154. When reheating operation control begins, control device 150 sets the first three-way valve 80 to the third connected state and sets the second three-way valve 82 to the fifth connected state (see reference). Figure 8 , Figure 9 In this state, control device 150 drives bathtub circulation pump 34, and the water begins to be heated by the second heat source unit 14. Accordingly, as Figure 9 As shown, water from bathtub 130 is supplied to the second heat source unit 14 via bathtub adapter 132, first bathtub water passage 62, first three-way valve 80, connecting passage 66, heat source circuit 60, and circulation circuit 32. Water heated by the second heat source unit 14 returns to bathtub 130 via circulation path 30, heat source path 68, second three-way valve 82, second bathtub water passage 70, and bathtub adapter 132. When the temperature detected by the thermistor 32a in the circulation circuit reaches or exceeds the set temperature, control device 150 stops bathtub circulation pump 34 and terminates water heating by the second heat source unit 14. After this, control device 150 informs the user via remote control 154 that the reheating operation is complete and terminates the reheating operation.

[0106] (Modified Example)

[0107] In the aforementioned hot water device 2, when implementing microbubble generation operation control, in Figure 10 In the S44 air intake adjustment process, instead of implementing Figure 11 The process shown can also be implemented by the control device 150. Figure 14 The processing is shown below. Figure 14 The processing shown is the same as Figure 11 The differences in the processing shown will be explained.

[0108] exist Figure 14 In the process shown, first in S82, the control device 150 is in standby mode until it starts from S38 (see reference). Figure 10 (or, in S76, the elapsed time since the opening of the first gas inlet valve 106 reaches the first predetermined time. The first predetermined time refers to the envisioned time for the water level in the storage tank 52 to drop from the upper limit water level to the lower limit water level while the first gas inlet valve 106 and the second gas inlet valve 108 are open, which is longer than S46 (refer to S76).) Figure 10The set time is a short time. When the elapsed time since the opening of the first gas inlet valve 106 reaches the first predetermined time (when this is the case), the process enters S64.

[0109] In addition, Figure 14 In the process shown, after S66, the process proceeds to S84. In S84, the control device 150 stands by until the elapsed time since the opening of the first gas inlet valve 106 in S64 reaches a second predetermined time. The second predetermined time refers to the envisioned time until the water level in the storage tank 52 rises from the lower limit water level to the upper limit water level with the first gas inlet valve 106 and / or the second gas inlet valve 108 closed, which is longer than S46 (see reference). Figure 10 The set time is a short time. When the elapsed time since the first gas inlet valve 106 was closed reaches the second specified time (when this is the case), the process enters S70.

[0110] according to Figure 14 The process shown allows for switching the opening and closing of the first gas inlet valve 106 and the second gas inlet valve 108 without the need for detection signals from the low water level electrode 52a or the high water level electrode 52b.

[0111] (Other variations)

[0112] In the aforementioned hot water device 2, the microbubble generation operation control, which is implemented in conjunction with the hot water injection operation control, can be omitted. Figure 10 The S32 cold water relief treatment.

[0113] In the aforementioned hot water device 2, it can also be omitted. Figure 10 S54 tank cleaning treatment.

[0114] In the aforementioned hot water device 2, it is also possible that... Figure 10 In the S46 operation control time determination process, even if the operation control time reaches the set time, it does not enter S48 but returns to S44 to continue the microbubble generation operation control until the user instructs the microbubble generation operation control to end via remote control 154.

[0115] In the aforementioned hot water device 2, it is also possible to replace... Figure 10 The order of processing in S34 and S36. That is, the control device 150 can also drive the tank circulation pump 94 in S36 after the cold water relief treatment in S32, and then open the second gas inlet valve 108 in S34.

[0116] In the aforementioned hot water device 2, it is also possible to... Figure 11 or Figure 14After closing the first gas inlet valve 106 in S64, the control device 150 stops the tank circulation pump 94. In this case, in S74 thereafter, the control device 150 drives the tank circulation pump 94 again to control the tank circulation pump 94 to a speed higher than the standard speed (e.g., 120% of the standard speed).

[0117] In the aforementioned hot water device 2, it is also possible to replace... Figure 11 or Figure 14 The processing order of S70, S72, and S74. For example, it could also be that the control device 150... Figure 11 S68 or Figure 14 If S84 is true, first stop the second pressurizing pump 90 in S72, and / or, in S74, make the speed of the tank circulation pump 94 higher than the standard speed, and then open the second gas inlet valve 108 in S70.

[0118] In the aforementioned hot water device 2, it can also be replaced by... Figure 11 or Figure 14 In step S72, the second booster pump 90 is stopped, and the speed of the first booster pump 88 and / or the second booster pump 90 is controlled by the control device 150 to make the speed of the first booster pump 88 and / or the second booster pump 90 lower than the standard speed (e.g., 80% of the standard speed). Even with this structure, the flow rate of water delivered by the first booster pump 88 and the second booster pump 90 can be reduced through the processing in S72. Alternatively, in this case, instead of... Figure 11 or Figure 14 In S80, the second pressurizing pump 90 is restarted, and the speed of the first pressurizing pump 88 and / or the second pressurizing pump 90 is controlled by the control device 150 so that the speed of the first pressurizing pump 88 and / or the second pressurizing pump 90 becomes the standard speed.

[0119] In the aforementioned hot water device 2, when the microbubble generation operation control is implemented in conjunction with the hot water injection operation control, it is not necessary to perform the operation at the end of the hot water injection operation control. Figure 7 The hot water injection completion notification for the S20 is not provided; instead, it is done during the microbubble generation operation control process. Figure 7 The hot water injection completion notification is provided by S20. More specifically, the hot water injection completion notification is given after the microbubble generation operation control time reaches a predetermined notification time (e.g., 2 minutes) sufficient for the water in the bathtub 130 to generate enough microbubbles. By adopting this structure, the time when the user enters the bathroom can be delayed, thereby preventing the user from entering the bathroom before the water in the bathtub 130 has sufficiently generated microbubbles.

[0120] In the hot water device 2 described above, it can also be configured such that the user can switch whether to implement microbubble generation operation control in conjunction with the hot water injection operation control via remote control 154.

[0121] In the hot water device 2 described above, air is introduced into the storage tank 52, or gases such as carbon dioxide, hydrogen, or oxygen can be introduced into the storage tank 52 instead of air. In this case, the gas filling tank (not shown) filled with gas can also be connected to the gas inlet 110 of the gas introduction path 104.

[0122] In the hot water device 2 described above, during the hot water injection operation control, a set amount of water is stored in the bathtub 130 based on the accumulated water volume detected by the water volume sensor 28. Alternatively, the hot water device 2 may be configured such that, for example, a water level sensor capable of detecting the water level in the bathtub 130 is provided, and during the hot water injection operation control, a set water level is stored in the bathtub 130 based on the water level detected by the water level sensor.

[0123] In the aforementioned hot water device 2, the heat source unit 10 is connected to the faucet 250, and the air pressurization and dissolving unit 50 is connected to the bathtub 130. Alternatively, the heat source unit 10 may be connected to other heat-utilizing components, and the air pressurization and dissolving unit 50 may be connected to other liquid tanks.

[0124] In the aforementioned hot water device 2, a one-way valve (not shown) may be installed downstream of the storage tank circulation pump 94 in the storage tank suction path 92. This one-way valve allows water to flow from the upstream side to the downstream side of the storage tank suction path 92 and prohibits water from flowing from the downstream side to the upstream side of the storage tank suction path 92. By installing a one-way valve in the storage tank suction path 92, even if the storage tank circulation pump 94 is stopped during the operation of the first booster pump 88 and the second booster pump 90, backflow of water delivered from the storage tank circuit 74 by the first booster pump 88 and the second booster pump 90 in the storage tank suction path 92 can be suppressed.

[0125] In the aforementioned hot water device 2, the gas introduction mechanism 96 is positioned upstream of the storage tank circulation pump 94 on the storage tank suction path 92. Conversely, the gas introduction mechanism 96 can also be positioned downstream of the storage tank circulation pump 94 on the storage tank suction path 92.

[0126] In the aforementioned hot water device 2, the downstream end of the storage tank circuit 74 and the downstream end of the storage tank suction path 92 are connected to the storage tank 52 via a shared storage tank connection path 76. Alternatively, it may differ from this, such as... Figure 15As shown, the air pressurization and dissolution unit 50 does not have a tank connection path 76. The downstream end of the tank circuit 74 (hereinafter referred to as inlet 74a) and the downstream end of the tank suction path 92 (hereinafter referred to as inlet 92b) are each separately connected to the tank 52. In this case, water flowing through the tank circuit 74 flows into the tank 52 via inlet 74a, and water flowing through the tank suction path 92 flows into the tank 52 via inlet 92b.

[0127] As described above, in one or more embodiments, the hot water device 2 (an example of a microbubble generating device) includes a storage tank 52, a storage tank circuit 74 and a storage tank connection path 76 (an example of a storage tank supply path), a first pressurizing pump 88 and a second pressurizing pump 90 (an example of a pressurizing pump), a storage tank outlet 64, a first bathtub water path 62 and a bathtub adapter 132 (an example of a storage tank discharge path), a microbubble generating nozzle 142, a storage tank suction path 92 and a storage tank connection path 76 (an example of a storage tank circulation path), a storage tank circulation pump 94, a gas introduction mechanism 96, and a control device 150. The storage tank 52 is used to pressurize and dissolve air (an example of a gas) in water (an example of a liquid); the storage tank circuit 74 and the storage tank connection path 76 are used to supply water to the storage tank 52; the first pressurizing pump 88 and the second pressurizing pump 90 ... The pressure pump 88 and the second pressure pump 90 are disposed in the tank circuit 74; the tank outlet 64, the first bathtub water circuit 62, and the bathtub adapter 132 are used to discharge pressurized water containing dissolved air from the tank 52 to the bathtub 130 (an example of a liquid tank); the microbubble generating nozzle 142 is disposed in the bathtub adapter 132 for generating microbubbles by depressurizing the pressurized water containing dissolved air; the tank suction path 92 and the tank connection path 76 are disposed separately from the tank outlet 64, the first bathtub water circuit 62, and the bathtub adapter 132 for conveying water from the outlet 92a connected to the tank 52 to the inlet 76a connected to the tank 52; the tank circulation pump 94 is disposed in the tank suction path 92; and the gas introduction mechanism 96 is disposed in the tank suction path 92. The gas introduction mechanism 96 includes a Venturi tube 102 (an example of a pressure-reducing section), a gas inlet 110, a gas introduction path 104, a first gas introduction valve 106, and a second gas introduction valve 108. The Venturi tube 102 reduces water pressure and allows it to pass through. The gas inlet 110 introduces air through the negative pressure of the water in the Venturi tube 102. The gas introduction path 104 connects the Venturi tube 102 and the gas inlet 110. The first gas introduction valve 106 is disposed in the gas introduction path 104 for opening and closing the gas introduction path 104. The second gas introduction valve 108 is disposed on the gas introduction path 104 between the first gas introduction valve 106 and the gas inlet 110 for opening and closing the gas introduction path 104. The first gas introduction valve 106 is configured such that when the negative pressure of the water in the Venturi tube 102 is applied, a force in the direction of opening the first gas introduction valve 106 is applied. The second gas inlet valve 108 is configured such that when the water in the venturi tube 102 is under negative pressure, it is subjected to a force in the direction that causes the second gas inlet valve 108 to close.The control device 150 is capable of implementing microbubble generation operation control, which refers to: driving the first pressurizing pump 88 and the second pressurizing pump 90 to pressurize and supply water from the storage tank circuit 74 and the storage tank connection path 76 to the storage tank 52, and supplying pressurized water containing dissolved air from the storage tank 52 to the bathtub 130 via the storage tank passage 64, the first bathtub water passage 62, and the bathtub adapter 132. During the microbubble generation operation control, the control device 150 can also implement storage tank circulation operation control, which refers to: circulating the water in the storage tank 52 through the storage tank suction path 92 and the storage tank connection path 76 via the storage tank circulation pump 94, creating a negative pressure in the venturi tube 102 of the gas introduction mechanism 96. The control device 150 is configured such that, when both the first gas introduction valve 106 and the second gas introduction valve 108 are changed from a closed state to an open state, the second gas introduction valve 108 is opened first, followed by the opening of the first gas introduction valve 106.

[0128] In the aforementioned hot water device 2, even while microbubble generation operation control is in progress, air can be introduced into the storage tank 52 by the gas introduction mechanism 96 and supplied to the storage tank 52 by implementing storage tank circulation operation control with the first gas introduction valve 106 and the second gas introduction valve 108 open. Therefore, microbubble generation operation control can be continuously implemented without interrupting it to supply air to the storage tank 52. With this structure, microbubbles can be stably generated in the water of the bathtub 130.

[0129] Furthermore, in the aforementioned hot water device 2, a first gas inlet valve 106 and a second gas inlet valve 108 are provided on the gas inlet path 104. The second gas inlet valve 108 is located between the first gas inlet valve 106 and the gas inlet port 110. When the negative pressure of the water in the Venturi tube 102 acts on the first gas inlet valve 106, a force in the direction of opening the first gas inlet valve 106 acts on the first gas inlet valve 106. When the negative pressure of the water in the Venturi tube 102 acts on the second gas inlet valve 108, a force in the direction of closing the second gas inlet valve 108 acts on the second gas inlet valve 108. Therefore, for example, when simultaneously implementing microbubble generation operation control and tank circulation operation control, causing both the first gas inlet valve 106 and the second gas inlet valve 108 to change from a closed state to an open state, if the first gas inlet valve 106 is opened first, then when the second gas inlet valve 108 is opened subsequently, the negative pressure of the water in the venturi tube 102 will act on the second gas inlet valve 108, raising concerns that the second gas inlet valve 108 may not operate smoothly. As described above, when simultaneously implementing microbubble generation operation control and tank circulation operation control, causing both the first gas inlet valve 106 and the second gas inlet valve 108 to change from a closed state to an open state, by opening the second gas inlet valve 108 first, the negative pressure of the water in the venturi tube 102 acting on the second gas inlet valve 108 can be suppressed, thereby ensuring the smooth operation of the second gas inlet valve 108.

[0130] In the hot water device 2, the control device 150 is configured such that, when the first gas inlet valve 106 is changed from a closed state to an open state during microbubble generation operation control, the flow rates of the first booster pump 88 and the second booster pump 90 are first reduced from a first flow rate (e.g., the flow rate when both the first booster pump 88 and the second booster pump 90 are driven) to a second flow rate smaller than the first flow rate (e.g., the flow rate when the first booster pump 88 is driven and the second booster pump 90 is stopped), and then the first gas inlet valve 106 is opened. Alternatively, the first flow rate may refer to the flow rate of the first booster pump 88 and the second booster pump 90 when the microbubble generation operation control is performed with the first gas inlet valve 106 closed, and the second flow rate may refer to the flow rate of the first booster pump 88 and the second booster pump 90 when both microbubble generation operation control and tank circulation operation control are performed with the first gas inlet valve 106 open. Alternatively, the first flow rate may refer to the flow rate of the first pressurizing pump 88 and the second pressurizing pump 90 when the water level of the storage tank 52 gradually rises during the implementation of microbubble generation operation control. The second flow rate may refer to the flow rate of the first pressurizing pump 88 and the second pressurizing pump 90 when the water level of the storage tank 52 gradually falls during the implementation of both microbubble generation operation control and storage tank circulation operation control.

[0131] When implementing microbubble generation control, if the flow rates of the first pressurizing pump 88 and the second pressurizing pump 90 are high, the pressure inside the storage tank 52 increases, and the water pressure in the Venturi tube 102 of the gas introduction mechanism 96 also increases. That is, the negative pressure of the water in the Venturi tube 102 decreases. Conversely, if the flow rates of the first pressurizing pump 88 and the second pressurizing pump 90 are low, the pressure inside the storage tank 52 decreases, and the water pressure in the Venturi tube 102 of the gas introduction mechanism 96 also decreases. That is, the negative pressure of the water in the Venturi tube 102 increases. The negative pressure of the water in the Venturi tube 102 exerts a force on the first gas introduction valve 106 in the direction of opening the first gas introduction valve 106. Therefore, when the first gas introduction valve 106 is opened, the lower the water pressure in the Venturi tube 102, the more smoothly the first gas introduction valve 106 can operate. According to the above structure, when the first gas inlet valve 106 is changed from a closed state to an open state, the flow rates of the first pressurizing pump 88 and the second pressurizing pump 90 are first reduced from the first flow rate to the second flow rate, thereby reducing the water pressure in the venturi tube 102 of the gas inlet mechanism 96. After that, the first gas inlet valve 106 is opened, thus enabling the first gas inlet valve 106 to operate smoothly.

[0132] In the hot water unit 2, the control device 150 is configured such that, when the first gas inlet valve 106 is changed from a closed state to an open state during tank circulation operation control, the flow rate of the tank circulation pump 94 is first increased from a third flow rate (e.g., the flow rate when the tank circulation pump 94 is driven at a standard speed) to a fourth flow rate greater than the third flow rate (e.g., the flow rate when the tank circulation pump 94 is driven at a high speed), and then the first gas inlet valve 106 is opened. Furthermore, the third flow rate can also refer to the flow rate of the tank circulation pump 94 when microbubble generation operation control is performed with the first gas inlet valve 106 closed (this is the flow rate of the tank circulation pump 94 when tank circulation operation control is performed with the first gas inlet valve 106 closed, and zero when tank circulation operation control is not performed with the first gas inlet valve 106 closed), and the fourth flow rate can also refer to the flow rate of the tank circulation pump 94 when both microbubble generation operation control and tank circulation operation control are performed with the first gas inlet valve 106 open. Alternatively, the third flow rate can refer to the flow rate of the tank circulation pump 94 when the water level of the tank 52 gradually rises during the implementation of microbubble generation operation control, and the fourth flow rate can refer to the flow rate of the tank circulation pump 94 when the water level of the tank 52 gradually falls during the implementation of both microbubble generation operation control and tank circulation operation control.

[0133] When implementing tank circulation operation control, if the flow rate of the tank circulation pump 94 is low, the water pressure in the Venturi tube 102 of the gas introduction mechanism 96 increases. That is, the negative pressure of the water in the Venturi tube 102 decreases. Conversely, if the flow rate of the tank circulation pump 94 is high, the water pressure in the Venturi tube 102 of the gas introduction mechanism 96 decreases. That is, the negative pressure of the water in the Venturi tube 102 increases. The negative pressure of the water in the Venturi tube 102 exerts a force on the first gas introduction valve 106 in the direction of opening the first gas introduction valve 106. Therefore, when the first gas introduction valve 106 is opened, the lower the water pressure in the Venturi tube 102, the smoother the operation of the first gas introduction valve 106. According to the above structure, when the first gas inlet valve 106 is changed from a closed state to an open state, the pressure of the water in the venturi tube 102 of the gas inlet mechanism 96 is reduced by first increasing the flow rate of the tank circulation pump 94 from the third flow rate to the fourth flow rate, and then the first gas inlet valve 106 is opened, so that the first gas inlet valve 106 can operate smoothly.

[0134] In the hot water device 2, the control device 150 is configured such that when both the first gas inlet valve 106 and the second gas inlet valve 108 are changed from an open state to a closed state, the first gas inlet valve 106 is closed first, and then the second gas inlet valve 108 is closed.

[0135] In the aforementioned hot water device 2, a first gas inlet valve 106 and a second gas inlet valve 108 are provided on the gas inlet path 104. The second gas inlet valve 108 is located between the first gas inlet valve 106 and the gas inlet port 110. When the negative pressure of the water in the Venturi tube 102 acts on the first gas inlet valve 106, a force in the direction of opening the first gas inlet valve 106 acts on the first gas inlet valve 106. When the negative pressure of the water in the Venturi tube 102 acts on the second gas inlet valve 108, a force in the direction of closing the second gas inlet valve 108 acts on the second gas inlet valve 108. Therefore, for example, when the microbubble generation operation control and the tank circulation operation control are implemented simultaneously, and both the first gas inlet valve 106 and the second gas inlet valve 108 are changed from the open state to the closed state, if the second gas inlet valve 108 is closed first, then when the second gas inlet valve 108 is closed, the negative pressure of the water in the venturi tube 102 acts on the second gas inlet valve 108, and the valve body 108c of the second gas inlet valve 108 violently hits the valve seat 108b, which may generate noise or damage the second gas inlet valve 108. As described above, when both the first gas inlet valve 106 and the second gas inlet valve 108 are changed from an open state to a closed state, by closing the first gas inlet valve 106 first, the negative pressure of the water in the venturi tube 102 acting on the second gas inlet valve 108 when the second gas inlet valve 108 is closed afterward can be suppressed. This can suppress noise or damage to the second gas inlet valve 108 caused by the valve body 108c of the second gas inlet valve 108 violently hitting the valve seat 108b.

[0136] The embodiments have been described in detail above, but these embodiments are merely examples and do not limit the scope of the technical solution. The technology described in the technical solution includes various modifications and variations to the specific examples exemplified above. The technical elements described in this specification or drawings, individually or in various combinations, exert their technical usefulness and are not limited to the combinations described in the technical solution at the time of application. Furthermore, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives is itself technically useful.

Claims

1. A microbubble generating device, characterized in that, It includes a storage tank, a storage tank supply path, a pressurizing pump, a storage tank discharge path, a microbubble generating nozzle, a storage tank circulation path, a storage tank circulation pump, a gas introduction mechanism, and a control device. The storage tank is used to pressurize and dissolve gas in a liquid; The tank supply path is used to supply the liquid to the tank; The pressurization pump is located in the supply path of the storage tank; The tank discharge path is used to discharge the pressurized liquid containing the gas dissolved in it from the tank to the liquid tank; The microbubble generating nozzle is disposed in the discharge path of the storage tank and is used to generate microbubbles by depressurizing the pressurized liquid containing the gas. The storage tank circulation path and the storage tank discharge path are set separately for conveying the liquid from the outlet connected to the storage tank to the inlet connected to the storage tank; The tank circulation pump is located in the tank circulation path; The gas introduction mechanism is located in the circulation path of the storage tank. The gas introduction mechanism includes a pressure reducing section, a gas inlet, a gas introduction path, a first gas introduction valve, and a second gas introduction valve, wherein... The pressure-reducing section depressurizes the liquid and allows it to pass through; The gas inlet is introduced by the negative pressure of the liquid in the pressure reducing section; The gas inlet path connects the pressure reducing unit and the gas inlet; The first gas inlet valve is disposed in the gas inlet path and is used to open and close the gas inlet path; The second gas inlet valve is disposed on the gas inlet path between the first gas inlet valve and the gas inlet port, and is used to open and close the gas inlet path. The first gas inlet valve is configured such that when the liquid in the pressure reducing section is under negative pressure, it is subjected to a force in the direction of opening the first gas inlet valve. The second gas inlet valve is configured such that when the liquid in the pressure reducing section is under negative pressure, it is subjected to a force in the direction that causes the second gas inlet valve to close. The control device is capable of implementing microbubble generation operation control, which means: driving the pressurizing pump to pressurize and supply the liquid from the tank supply path to the tank, and supplying the pressurized liquid containing the gas dissolved from the tank to the liquid tank via the tank discharge path; The control device is capable of implementing tank circulation operation control. This tank circulation operation control refers to the following: during the microbubble generation operation control, the liquid in the tank is circulated in the tank circulation path by the tank circulation pump, thereby generating negative pressure in the pressure reducing section of the gas introduction mechanism. The control device is configured such that, when both the first gas inlet valve and the second gas inlet valve are changed from a closed state to an open state, the second gas inlet valve is opened first, and then the first gas inlet valve is opened. The upstream end of the storage tank circulation path is connected to the storage tank through the outlet, while the upstream end of the storage tank discharge path is not connected to the storage tank through the outlet. Liquid flowing from the storage tank through the outlet flows into the storage tank through the inlet, bypassing the liquid tank and instead passing through the storage tank circulation path.

2. The microbubble generator according to claim 1, characterized in that, The control device is configured such that when the microbubble generation operation control is implemented and the first gas inlet valve is changed from a closed state to an open state, the flow rate of the pressurizing pump is first reduced from a first flow rate to a second flow rate that is smaller than the first flow rate, and then the first gas inlet valve is opened.

3. The microbubble generator according to claim 1, characterized in that, The control device is configured such that when the first gas inlet valve is changed from a closed state to an open state during the tank circulation operation control, the flow rate of the tank circulation pump is first increased from a third flow rate to a fourth flow rate that is greater than the third flow rate, and then the first gas inlet valve is opened.

4. The microbubble generating apparatus according to any one of claims 1 to 3, characterized in that, The control device is configured such that, when both the first gas inlet valve and the second gas inlet valve are changed from an open state to a closed state, the first gas inlet valve is closed first, and then the second gas inlet valve is closed.

5. The microbubble generator according to claim 1, characterized in that, The liquid is water. The liquid tank is a bathtub used by users for bathing.

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