Microbubble generating device

Abstract

The control device of the microbubble generating device can implement microbubble generation operation control, which refers to driving the pressurizing pump to pressurize and supply liquid from the tank supply path to the tank, and supplying liquid from the tank to the liquid tank via the tank discharge path. The control device can implement first tank circulation operation control and second tank circulation operation control during the implementation of the microbubble generation operation control. The first tank circulation operation control refers to circulating the liquid in the tank in the tank circulation path by the tank circulation pump in a state where the gas introduction valve is open. The second tank circulation operation control refers to circulating the liquid in the tank in the tank circulation path by the tank circulation pump in a state where the gas introduction valve is closed. The control device drives the tank circulation pump at a first rotational speed in the first tank circulation operation control, and drives the tank circulation pump at a second rotational speed in the second tank circulation operation control. Accordingly, the liquid in the liquid tank can be stably and continuously supplied with 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; and a gas introducing valve 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. Existing technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Publication No. 2009-18118 Summary of the Invention [The technical problem that the invention aims to solve]

[0004] 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. [Technical means used to solve technical problems]

[0005] 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, and a gas introduction valve. The pressure reducing section depressurizes the liquid as it passes through; the gas inlet introduces the gas through the negative pressure of the liquid in the pressure reducing section; and the gas introduction valve opens and closes the gas inlet. 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 storage tank supply path to the storage tank, and supplying pressurized liquid containing the dissolved gas from the storage tank to the liquid tank via the storage tank discharge path. The control device is also capable of implementing first and second storage tank circulation operation control during the microbubble generation operation control. The first storage tank circulation operation control refers to: circulating the liquid in the storage tank in the storage tank circulation path using the storage tank circulation pump while the gas introduction valve is open; the second storage tank circulation operation control refers to: circulating the liquid in the storage tank in the storage tank circulation path using the storage tank circulation pump while the gas introduction valve is closed. The control device is configured to drive the tank circulation pump at a first rotational speed in the first tank circulation operation control, and drive the tank circulation pump at a second rotational speed lower than the first rotational speed in the second tank circulation operation control.

[0006] In the aforementioned microbubble generating device, even while microbubble generation operation control is in progress, gas can be introduced into and supplied to the storage tank by the gas introduction mechanism through the first storage tank circulation operation control. Therefore, microbubble generation operation control can be continuously implemented without interrupting it to supply gas to the storage tank. This structure enables the stable and continuous generation of microbubbles from the liquid in the liquid tank.

[0007] Furthermore, in the aforementioned microbubble generating device, when the first or second tank circulation operation control is implemented during the microbubble generation operation control, the flow of liquid within the tank becomes rapid. In a pressurized dissolution type tank, the faster the liquid flow within the tank, the more it promotes the pressurized dissolution of gas into the liquid within the tank. Based on the above structure, by implementing the first or second tank circulation operation control during the microbubble generation operation control, the liquid within the tank can flow more rapidly, thereby further promoting the pressurized dissolution of gas into the liquid within the tank.

[0008] Furthermore, in the first tank circulation operation control, gas is introduced into the pressure-reducing section of the gas introduction mechanism, thus relieving the negative pressure of the liquid in the pressure-reducing section by mixing the gas with the liquid. However, in the second tank circulation operation control, no gas is introduced into the pressure-reducing section of the gas introduction mechanism, therefore, the negative pressure of the liquid in the pressure-reducing section is not relieved. Therefore, assuming the tank circulation pump speed is the same in both the first and second tank circulation operation controls, the liquid pressure in the pressure-reducing section of the gas introduction mechanism becomes lower in the second tank circulation operation control compared to the first tank circulation operation control. When the liquid pressure in the pressure-reducing section of the gas introduction mechanism becomes too low, there is a concern that cavitation may occur in the pressure-reducing section, generating noise. According to the above structure, by making the speed of the tank circulation pump in the second tank circulation operation control lower than the speed of the tank circulation pump in the first tank circulation operation control, it is possible to suppress the liquid pressure in the pressure reducing section of the gas introduction mechanism in the second tank circulation operation control from becoming too low. Accordingly, it is possible to suppress cavitation in the pressure reducing section of the gas introduction mechanism in the second tank circulation operation control, thereby suppressing noise generation.

[0009] Furthermore, when implementing the first tank circulation operation control during the microbubble generation operation control, if the flow rate of the liquid flowing in the pressure reducing section of the gas introduction mechanism increases, the pressure of the liquid in the pressure reducing section correspondingly decreases, thereby allowing more gas to be introduced by the gas introduction mechanism. Based on the above structure, by making the rotational speed of the tank circulation pump in the first tank circulation operation control higher than the rotational speed of the tank circulation pump in the second tank circulation operation control, more gas can be introduced by the gas introduction mechanism in the first tank circulation operation control.

[0010] In the microbubble generator, the gas introduction mechanism may also be configured in the tank circulation path at a position upstream of the tank circulation pump.

[0011] In the first tank circulation operation control, when the gas introduction mechanism is positioned upstream of the tank circulation pump in the tank circulation path, the gas introduced by the gas introduction mechanism mixes with the liquid and flows into the tank circulation pump. Therefore, compared to the case where the gas introduction mechanism is positioned downstream of the tank circulation pump in the tank circulation path, the efficiency of the tank circulation pump decreases, and the flow rate of the liquid flowing in the pressure reducing section of the gas introduction mechanism decreases. In contrast, in the second tank circulation operation control, even when the gas introduction mechanism is positioned upstream of the tank circulation pump in the tank circulation path, since gas is not introduced by the gas introduction mechanism, the efficiency of the tank circulation pump does not decrease compared to the case where the gas introduction mechanism is positioned downstream of the tank circulation pump in the tank circulation path, and the flow rate of the liquid flowing in the pressure reducing section of the gas introduction mechanism does not decrease. Therefore, assuming the tank circulation pump speed is the same in both the first and second tank circulation operation controls, in the second tank circulation operation control, compared to the first tank circulation operation control, the flow rate of liquid flowing in the pressure-reducing section of the gas introduction mechanism becomes larger, and the liquid pressure in the pressure-reducing section of the gas introduction mechanism becomes lower. Consequently, cavitation is more likely to occur in the pressure-reducing section of the gas introduction mechanism, thus increasing noise generation. Based on the above structure, by making the tank circulation pump speed in the second tank circulation operation control lower than that in the first tank circulation operation control, the occurrence of cavitation in the pressure-reducing section can be suppressed in the second tank circulation operation control, thereby suppressing noise generation.

[0012] Furthermore, when the gas introduction mechanism is positioned upstream of the tank circulation pump in the tank circulation path, the suction pressure of the tank circulation pump acts on the pressure reducing section of the gas introduction mechanism. Therefore, compared to when the gas introduction mechanism is positioned downstream of the tank circulation pump in the tank circulation path, the liquid pressure in the pressure reducing section becomes lower. Thus, in the first tank circulation operation control, a greater amount of gas can be introduced by the gas introduction mechanism. Additionally, according to the above structure, in the first tank circulation operation control, the gas introduced by the gas introduction mechanism and the liquid flowing in the tank circulation path are agitated by the impeller of the tank circulation pump when passing through it, thus further promoting the dissolution of gas into the liquid.

[0013] The microbubble generator may also include a first liquid level electrode and a second liquid level electrode, wherein the first liquid level electrode can detect whether the liquid level in the tank is above a first liquid level; and the second liquid level electrode can detect whether the liquid level in the tank is above a second liquid level, which is higher than the first liquid level. Alternatively, the liquid level at the location where the outlet of the circulation path to the tank is connected to the tank may be lower than the first liquid level. The control device may also be configured to, when detecting that the liquid level in the tank is lower than the first liquid level during the implementation of both microbubble generation operation control and first tank circulation operation control, terminate the first tank circulation operation control and begin the second tank circulation operation control; conversely, when detecting that the liquid level in the tank is higher than the second liquid level during the implementation of both microbubble generation operation control and second tank circulation operation control, terminate the second tank circulation operation control and begin the first tank circulation operation control.

[0014] During the microbubble generation operation control, when the amount of gas consumed by the storage tank is less than the amount of gas introduced by the gas introducing mechanism, the liquid level in the storage tank drops; conversely, when the amount of gas consumed by the storage tank is greater than the amount of gas introduced by the gas introducing mechanism, the liquid level in the storage tank rises. On the other hand, when the storage tank circulation pump is being driven, gas is introduced by the gas introducing mechanism when the first storage tank circulation operation control is implemented, but gas is not introduced by the gas introducing mechanism when the second storage tank circulation operation control is implemented. Based on the above structure, the control device selectively implements either the first storage tank circulation operation control or the second storage tank circulation operation control according to the liquid level in the storage tank, thereby balancing the amount of gas consumed by the storage tank and the amount of gas introduced by the gas introducing mechanism.

[0015] The gas inlet valve can also be configured such that it is closed by a force in the direction of the liquid in the pressure reducing section. The control device can also be configured such that, when the first tank circulation operation control ends and the second tank circulation operation control begins, it continues to drive the tank circulation pump while reducing the speed of the tank circulation pump from the first speed to the second speed, and then closes the gas inlet valve.

[0016] In the above structure, the negative pressure of the liquid in the pressure-reducing section acts on the gas inlet valve in the direction that closes it. Therefore, when the gas inlet valve is switched from the open to the closed state when the pressure of the liquid in the pressure-reducing section is low, the valve body of the gas inlet valve may strongly impact the valve seat, raising concerns about noise generation and damage to the gas inlet valve. In the above structure, when the control device ends the first tank circulation operation control and begins the second tank circulation operation control, it reduces the speed of the tank circulation pump to increase the pressure of the liquid in the pressure-reducing section, and then switches the gas inlet valve from the open to the closed state. Accordingly, it is possible to suppress noise or damage to the gas inlet valve caused by the valve body of the gas inlet valve strongly impacting the valve seat.

[0017] The gas inlet valve can also be configured such that it is closed by a force in the direction of the liquid in the pressure reducing section. The control device can also be configured such that, when the second tank circulation operation control ends and the first tank circulation operation control begins, the gas inlet valve is opened while the tank circulation pump is continuously driven, and thereafter the rotational speed of the tank circulation pump is increased from the second rotational speed to the first rotational speed.

[0018] In the above structure, the negative pressure of the liquid in the pressure-reducing section acts on the gas inlet valve in the direction that closes it. Therefore, there is a concern that the gas inlet valve may not operate smoothly when switching from a closed to an open state when the liquid pressure in the pressure-reducing section is low. In the above structure, when the control device ends the second tank circulation operation control and starts the first tank circulation operation control, it switches the gas inlet valve from a closed to an open state, increases the speed of the tank circulation pump, and reduces the pressure of the liquid in the pressure-reducing section. Accordingly, the gas inlet valve can be operated sequentially.

[0019] 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.

[0020] Based on the above structure, the water in the bathtub used by the user can continuously and stably generate tiny bubbles. Attached Figure Description

[0021] Figure 1 This is a diagram schematically illustrating the structure of the hot water device 2 in an embodiment. Figure 2 This is a schematic cross-sectional view of the bathtub adapter 132 of the hot water device 2 in an embodiment. Figure 3 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. Figure 4This is a diagram schematically illustrating an example of water flow in the hot water device 2 of an embodiment. Figure 5 This is a diagram illustrating another example of water flow in the hot water device 2 of the embodiment. Figure 6 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. Figure 7 This is a diagram illustrating yet another example of water flow in the hot water device 2 of the embodiment. Figure 8 This is a diagram illustrating yet another example of water flow in the hot water device 2 of the embodiment. Figure 9 This is a flowchart of the process implemented by the control device 150 in the microbubble generation operation control of the modified hot water device 2. Figure 10 This is a schematic diagram illustrating the structure of another modified example of a hot water device 2. Explanation of reference numerals in the attached figures 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: Flow switch; 50: Air heater Pressure 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 outflow; 66: Connecting circuit; 68: Heat source outflow; 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 pressurizing pump; 90: Second 92: Pressure pump; 92: Tank suction path; 92a: Outlet; 92b: Inlet; 94: Tank circulation pump; 96: Gas introduction mechanism; 98: Water inlet pipe; 100: Water outlet pipe; 102: Venturi tube; 104: Gas introduction path; 104a: Gas inlet; 106: Gas introduction valve; 130: Bathtub; 130a: Wall; 132: Bathtub adapter; 132a: Front surface; 132b: Lower surface; 134a: First outlet; 134b: First suction inlet; 134c 134d: Second intake port; 136: First water path; 136a: First discharge path; 136b: First intake path; 138: Second water path; 138a: Second discharge path; 138b: Second intake 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

[0022] (Example) like Figure 1 As 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.

[0023] (Structure of heat source unit 10) 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] (Structure of the air pressurized dissolution unit 50) 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.

[0030] 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.

[0031] 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 7 , Figure 8 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 4 , Figure 5 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.

[0032] 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 7 , Figure 8 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 4 , Figure 5 One 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.

[0033] 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.

[0034] 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.

[0035] 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, and a gas introduction valve 106. 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 both 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 level as it flows from the venturi tube 102 to the outlet pipe 100. The upstream end of the gas inlet path 104 (hereinafter referred to as gas inlet 104a) is open to the atmosphere, and the downstream end is connected to the venturi tube 102. A gas inlet valve 106 is disposed in the gas inlet path 104 to open and close the gas inlet path 104. The gas inlet valve 106 includes: a valve body (not shown); a valve seat (not shown); a spring (not shown) that applies force to the valve body in the direction of sitting on the valve seat; and an electromagnetic coil (not shown) that moves the valve body away from the valve seat. The gas inlet valve 106 is closed when the valve body is seated on the valve seat due to the spring's loading force. The gas inlet valve 106 opens when the valve body is moved away from the valve seat by the electromagnetic coil. When water flows through the gas inlet mechanism 96 and the gas inlet valve 106 is in the open state, air is drawn into the gas inlet path 104 from the gas inlet 104a, and the air mixes with the water flowing through the venturi tube 102. Air introduced through gas inlet path 104 mixes with water flowing through tank suction path 92 and flows into tank 52 via tank connection path 76. Gas inlet valve 106 is normally closed, but opens when the solenoid coil is driven by control device 150 (described later). The negative pressure of the water in venturi tube 102 acts on gas inlet valve 106 in the direction that closes it.

[0036] 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 from the tank circuit 74 to the tank 52 at high pressure.

[0037] (Structure of bathtub adapter 132) Next, refer to Figure 2 (a) and (b) in the text describe the bathtub adapter 132 installed on the wall 130a of the bathtub 130. Figure 2 (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 7 The water flow in the bathtub adapter 132 under the condition of (state). Figure 2 (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 5 The water flow in the bathtub adapter 132 under the condition of (state).

[0038] 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.

[0039] 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.

[0040] (Structure of control device 150) 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).

[0041] (Hot water injection operation control) 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 4 , Figure 5 In this state, control device 150 performs... Figure 3 The processing is shown.

[0042] In S2, control device 150 performs venting. Specifically, control device 150 opens hot water injection valve 26 and begins heating water by the first heat source unit 12. Accordingly, as Figure 4 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.

[0043] In S4, the control device 150 performs residual water detection and processing in the bathtub 130. Specifically, as follows... Figure 5As 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.

[0044] 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 5 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.

[0045] 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.

[0046] 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 4As 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.

[0047] 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.

[0048] In S14, the control device 150 closes the hot water injection valve 26, ending the heating of water by the first heat source 12.

[0049] 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.

[0050] 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 5 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.

[0051] 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 3 The processing is now complete.

[0052] (Microbubble generation operation control) 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 4 , Figure 5 In this state, control device 150 performs... Figure 6 The processing is shown.

[0053] 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 5 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.

[0054] In step S34, 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 step S34, the control device 150 controls the tank circulation pump 94 to achieve a predetermined second rotational speed. This second rotational speed is lower than the first rotational speed (described later), for example, 80% of the first rotational speed.

[0055] In step S36, control device 150 opens gas inlet valve 106. Accordingly, air is introduced into the water flowing through gas inlet mechanism 96 of tank suction path 92.

[0056] In S38, the control device 150 controls the tank circulation pump 94 so that the rotational speed of the tank circulation pump 94 is a predetermined first rotational speed.

[0057] In S40, control device 150 begins supplying air-dissolved water from storage tank 52 to bathtub 130. Specifically, as... Figure 7 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.

[0058] In S42, 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, the amount of air introduced when the gas introduction valve 106 is opened in the gas introduction mechanism 96 is greater than the amount of air generated by the tiny bubbles in the water of the bathtub 130. Therefore, with the gas introduction valve 106 open, the amount of air in the storage tank 52 increases, and the water level in the storage tank 52 decreases. If the water level in the storage tank 52 is below the lower limit water level (if yes), the process proceeds to S44. If the water level in the storage tank 52 is above the lower limit water level (if no), the process proceeds to S48.

[0059] In S44, the control device 150 controls the tank circulation pump 94 so that the rotational speed of the tank circulation pump 94 becomes the second rotational speed.

[0060] In step S46, the control device 150 closes the 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 gas inlet valve 106 is closed. This promotes the flow of water within the tank 52, thereby promoting the pressurized dissolution of air in the water within the tank 52.

[0061] In step S48, 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 gas inlet valve 106 closed, no air is supplied to the storage tank 52; therefore, the amount of air in the storage tank 52 decreases, and the water level in the storage tank 52 rises. If the water level in the storage tank 52 is above the upper limit water level (if yes), the process proceeds to step S50. If the water level in the storage tank 52 is below the upper limit water level (if no), the process proceeds to step S54.

[0062] In S50, the control device 150 opens the gas inlet valve 106. Accordingly, air is once again introduced into the water flowing through the gas inlet mechanism 96 of the storage tank suction path 92.

[0063] In S52, the control device 150 controls the tank circulation pump 94 so that the rotational speed of the tank circulation pump 94 becomes the first rotational speed.

[0064] In S54, 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, for example, set to 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, for example, set to 30 minutes. If the operation control time has not reached the set time (if not), the process returns to S42. When the operation control time has reached the set time (if yes), the process proceeds to S56.

[0065] In S56, 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.

[0066] In S58, the control device 150 closes the 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 storage tank suction path 92.

[0067] In S60, 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 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, 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.

[0068] In S62, control device 150 stops the 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 6 The processing is now complete.

[0069] (Reheating operation control) 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 4 , Figure 5 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 5 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.

[0070] (Modified Example) In the aforementioned hot water device 2, when implementing microbubble generation operation control, it replaces the implementation of... Figure 6 The process shown can also be implemented by the control device 150. Figure 9 The processing is shown below. Figure 9The processing shown is the same as Figure 6 The differences in the processing shown will be explained.

[0071] exist Figure 9 In the process shown, after S40 and if S54 is not true, the process proceeds to S64. In S64, the control device 150 stands by until the elapsed time since the gas inlet valve 106 was opened in S36 or S50 reaches a 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 gas inlet valve 106 is open, which is a shorter time than the set time in S54. When the elapsed time since the gas inlet valve 106 was opened reaches the first predetermined time (if yes), the process proceeds to S44.

[0072] In addition, Figure 9 In the process shown, after S46, the process proceeds to S66. In S66, the control device 150 stands by until the elapsed time since the gas inlet valve 106 was closed in S46 reaches a second predetermined time. The second predetermined time refers to the envisioned time for the water level in the storage tank 52 to rise from the lower limit water level to the upper limit water level while the gas inlet valve 106 is closed, which is a shorter time than the set time in S54. When the elapsed time since the gas inlet valve 106 was closed reaches the second predetermined time (i.e., when this time is reached), the process proceeds to S50.

[0073] according to Figure 9 The process shown allows for switching the opening and closing of the gas inlet valve 106 without the need for detection signals from the low water level electrode 52a or the high water level electrode 52b.

[0074] (Other variations) 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 6 , Figure 9 The S32 cold water relief treatment.

[0075] In the aforementioned hot water device 2, it can also be omitted. Figure 6 , Figure 9 S60 storage tank cleaning treatment.

[0076] In the aforementioned hot water device 2, it is also possible that... Figure 6 or Figure 9 In the S54 operation control time determination process, even if the operation control time reaches the set time, it does not enter S56 but returns to S42 or S64 to continue the microbubble generation operation control until the user instructs the microbubble generation operation control to end via remote control 154.

[0077] 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 3 The hot water injection completion notification for the S20 is not provided; instead, it is done during the microbubble generation operation control process. Figure 3 The hot water injection completion notification is provided in S20. More specifically, the hot water injection completion notification can also be provided after the operation control time for microbubble generation has reached 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.

[0078] 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.

[0079] 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 104a of the gas introduction path 104.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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 10 As 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.

[0085] 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 104a, and a gas introduction valve 106. The Venturi tube 102 allows water to pass through under pressure; the gas inlet 104a introduces air through the negative pressure of the water in the Venturi tube 102; and the gas introduction valve 106 opens and closes the gas inlet 104a. The control device 150 is capable of implementing microbubble generation operation control, which means: 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 outlet 64, the first bathtub water path 62, and the bathtub adapter 132. During the microbubble generation operation control, the control device 150 can implement first tank circulation operation control and second tank circulation operation control. The first tank circulation operation control refers to: with the gas inlet valve 106 open, the water in the tank 52 is circulated in the tank suction path 92 and the tank connection path 76 by the tank circulation pump 94. The second tank circulation operation control refers to: with the gas inlet valve 106 closed, the water in the tank 52 is circulated in the tank suction path 92 and the tank connection path 76 by the tank circulation pump 94.The control device 150 is configured to drive the tank circulation pump 94 at a first rotational speed in the first tank circulation operation control, and drive the tank circulation pump 94 at a second rotational speed lower than the first rotational speed in the second tank circulation operation control.

[0086] In the aforementioned hot water device 2, even while microbubble generation operation control is in progress, air can be introduced by the gas introduction mechanism 96 and supplied to the storage tank 52 by implementing the first storage tank circulation operation control. 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 and continuously generated in the water of the bathtub 130.

[0087] Furthermore, in the aforementioned hot water device 2, when the first or second tank circulation operation control is implemented during the microbubble generation operation control, the water flow in tank 52 becomes rapid. In the pressurized dissolution type tank 52, the faster the water flow, the more it promotes the pressurized dissolution of air in the water within tank 52. Based on the above structure, by implementing the first or second tank circulation operation control during the microbubble generation operation control, the water in tank 52 can flow more rapidly, thereby further promoting the pressurized dissolution of air in the water within tank 52.

[0088] Furthermore, in the first tank circulation operation control, air is introduced into the venturi tube 102 of the gas introduction mechanism 96, thus relieving the negative pressure of the water in the venturi tube 102 by mixing air with water. However, in the second tank circulation operation control, no air is introduced into the venturi tube 102 of the gas introduction mechanism 96, therefore the negative pressure of the water in the venturi tube 102 is not relieved. Therefore, assuming that the rotational speed of the tank circulation pump 94 is the same in both the first and second tank circulation operation controls, the water pressure in the venturi tube 102 of the gas introduction mechanism 96 becomes lower in the second tank circulation operation control compared to the first tank circulation operation control. When the water pressure in the venturi tube 102 of the gas introduction mechanism 96 becomes too low, there is a concern that cavitation may occur in the venturi tube 102, generating noise. According to the above structure, by making the rotational speed of the tank circulation pump 94 in the second tank circulation operation control lower than the rotational speed of the tank circulation pump 94 in the first tank circulation operation control, it is possible to suppress the water pressure in the venturi tube 102 of the gas introduction mechanism 96 in the second tank circulation operation control from becoming too low. Accordingly, it is possible to suppress cavitation in the venturi tube 102 of the gas introduction mechanism 96 in the second tank circulation operation control, thereby suppressing noise generation.

[0089] Furthermore, when implementing the first tank circulation operation control during the microbubble generation operation control, if the flow rate of water flowing in the venturi tube 102 of the gas introduction mechanism 96 increases, the water pressure in the venturi tube 102 correspondingly decreases, thereby allowing more air to be introduced by the gas introduction mechanism 96. Based on the above structure, by making the rotational speed of the tank circulation pump 94 in the first tank circulation operation control higher than the rotational speed of the tank circulation pump 94 in the second tank circulation operation control, more air can be introduced by the gas introduction mechanism 96 in the first tank circulation operation control.

[0090] In one or more embodiments, the gas introduction mechanism 96 is configured in the tank suction path 92 at a position upstream of the tank circulation pump 94.

[0091] In the first tank circulation operation control, when the gas introduction mechanism 96 is positioned upstream of the tank circulation pump 94 in the tank suction path 92, the air introduced by the gas introduction mechanism 96 mixes with water and flows into the tank circulation pump 94. Therefore, compared to the case where the gas introduction mechanism 96 is positioned downstream of the tank circulation pump 94 in the tank suction path 92, the efficiency of the tank circulation pump 94 decreases, and the flow rate of water flowing in the venturi tube 102 of the gas introduction mechanism 96 becomes smaller. In contrast, in the second tank circulation operation control, even if the gas introduction mechanism 96 is positioned upstream of the tank circulation pump 94 in the tank suction path 92, air will not be introduced by the gas introduction mechanism 96. Therefore, compared to the case where the gas introduction mechanism 96 is positioned downstream of the tank circulation pump 94 in the tank suction path 92, the efficiency of the tank circulation pump 94 does not decrease, and the flow rate of water flowing in the Venturi tube 102 of the gas introduction mechanism 96 does not decrease. Therefore, assuming that the rotational speed of the tank circulation pump 94 is the same in both the first and second tank circulation operation controls, in the second tank circulation operation control, compared to the first tank circulation operation control, the flow rate of water flowing in the Venturi tube 102 of the gas introduction mechanism 96 becomes larger, and the water pressure in the Venturi tube 102 of the gas introduction mechanism 96 becomes lower. Consequently, cavitation is more likely to occur in the Venturi tube 102 of the gas introduction mechanism 96, thus increasing the likelihood of noise generation. According to the above structure, by making the speed of the tank circulation pump 94 in the second tank circulation operation control lower than the speed of the tank circulation pump 94 in the first tank circulation operation control, the generation of cavitation in the venturi tube 102 can be suppressed in the second tank circulation operation control, thereby suppressing noise generation.

[0092] Furthermore, when the gas introduction mechanism 96 is positioned upstream of the storage tank circulation pump 94 in the storage tank suction path 92, the suction pressure of the storage tank circulation pump 94 acts on the venturi tube 102 of the gas introduction mechanism 96. Therefore, compared to when the gas introduction mechanism 96 is positioned downstream of the storage tank circulation pump 94 in the storage tank suction path 92, the water pressure in the venturi tube 102 becomes lower. Thus, in the first storage tank circulation operation control, a greater amount of air can be introduced by the gas introduction mechanism 96. Additionally, according to the above structure, in the first storage tank circulation operation control, the air introduced by the gas introduction mechanism 96 and the water flowing in the storage tank suction path 92 are agitated by the impeller of the storage tank circulation pump 94 as they pass through it, thus further promoting the dissolution of air into the water.

[0093] In one or more embodiments, the hot water device 2 further includes a low water level electrode 52a (an example of a first liquid level electrode) and a high water level electrode 52b (an example of a second liquid level electrode), wherein the low water level electrode 52a is an electrode capable of detecting whether the water level (an example of a liquid level) in the storage tank 52 is above the lower limit water level (an example of a first liquid level); and the high water level electrode 52b is an electrode capable of detecting whether the water level in the storage tank 52 is above the upper limit water level (an example of a second liquid level), which is higher than the lower limit water level. The water level at the portion of the outlet 92a leading to the storage tank suction path 92 connected to the storage tank 52 is lower than the lower limit water level. The control device 150 is configured such that, when it detects that the water level in tank 52 is lower than the lower limit water level during the implementation of microbubble generation operation control and the implementation of first tank circulation operation control, it terminates the first tank circulation operation control and starts the second tank circulation operation control; when it detects that the water level in tank 52 is higher than the upper limit water level during the implementation of microbubble generation operation control and the implementation of second tank circulation operation control, it terminates the second tank circulation operation control and starts the first tank circulation operation control.

[0094] During the microbubble generation operation control, if the amount of air consumed by the storage tank 52 is less than the amount of air introduced by the gas introducing mechanism 96, the water level in the storage tank 52 drops; conversely, if the amount of air consumed by the storage tank 52 is greater than the amount of air introduced by the gas introducing mechanism 96, the water level in the storage tank 52 rises. On the other hand, when the storage tank circulation pump 94 is being driven, air is introduced by the gas introducing mechanism 96 during the first storage tank circulation operation control, but not during the second storage tank circulation operation control. Based on this structure, the control device 150 selectively implements either the first or second storage tank circulation operation control according to the water level in the storage tank 52, thereby balancing the amount of air consumed by the storage tank 52 and the amount of air introduced by the gas introducing mechanism 96.

[0095] In one or more embodiments, the gas inlet valve 106 is configured to be closed by a force in the direction of the negative pressure of the water in the Venturi tube 102. The control device 150 is configured to, when the first tank circulation operation control ends and the second tank circulation operation control begins, reduce the speed of the tank circulation pump 94 from the first speed to the second speed while continuing to drive the tank circulation pump 94, and then close the gas inlet valve 106.

[0096] In the above structure, the negative pressure of the water in the Venturi tube 102 acts on the gas inlet valve 106 in the direction that closes it. Therefore, when the gas inlet valve 106 is switched from the open state to the closed state when the water pressure in the Venturi tube 102 is low, the valve body of the gas inlet valve 106 may strongly impact the valve seat, raising concerns about noise generation and damage to the gas inlet valve 106. In the above structure, when the control device 150 ends the first tank circulation operation control and begins the second tank circulation operation control, it reduces the speed of the tank circulation pump 94, increases the water pressure in the Venturi tube 102, and then switches the gas inlet valve 106 from the open state to the closed state. Accordingly, it is possible to suppress noise or damage to the gas inlet valve 106 caused by the valve body of the gas inlet valve strongly impacting the valve seat.

[0097] In one or more embodiments, the gas inlet valve 106 is configured to be closed by a force in the direction of the negative pressure of the water in the Venturi tube 102. The control device 150 is configured to open the gas inlet valve 106 while continuing to drive the tank circulation pump 94 when the second tank circulation operation control ends and the first tank circulation operation control begins, and thereafter increase the speed of the tank circulation pump 94 from the second speed to the first speed.

[0098] In the above structure, the negative pressure of the water in the Venturi tube 102 acts on the gas inlet valve 106 in the direction that closes it. Therefore, there is a concern that the gas inlet valve 106 may not operate smoothly when the water pressure in the Venturi tube 102 is low, as it is possible to switch the gas inlet valve 106 from the closed state to the open state. In the above structure, when the control device 150 ends the second tank circulation operation control and starts the first tank circulation operation control, after switching the gas inlet valve 106 from the closed state to the open state, it increases the speed of the tank circulation pump 94 and reduces the water pressure in the Venturi tube 102. Accordingly, the gas inlet valve 106 can operate smoothly.

[0099] 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, and a 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 valve is used to open and close the gas inlet. The control device is capable of implementing microbubble generation operation control, which refers to: driving the pressurization pump to pressurize and supply the liquid from the tank supply path to the tank, and supplying the pressurized liquid containing the dissolved gas from the tank to the liquid tank via the tank discharge path. The control device is capable of implementing first tank circulation control and second tank circulation control during the microbubble generation operation control. The first tank circulation control refers to the operation control that, with the gas inlet valve open, uses the tank circulation pump to circulate the liquid in the tank within the tank circulation path. The second tank circulation control refers to the operation control that, with the gas inlet valve closed, uses the tank circulation pump to circulate the liquid in the tank within the tank circulation path. The control device is configured to drive the tank circulation pump at a first rotational speed in the first tank circulation operation control, and drive the tank circulation pump at a second rotational speed lower than the first rotational speed in the second tank circulation operation control. The control device is configured as follows: If, during the implementation of the microbubble generation operation control and the implementation of the first tank circulation operation control, it is detected that the liquid level in the tank is lower than the first liquid level, or if the elapsed time since the start of the first tank circulation operation control reaches the first predetermined time, the first tank circulation operation control is terminated and the second tank circulation operation control is started. If, during the implementation of the microbubble generation operation control and the implementation of the second tank circulation operation control, it is detected that the liquid level in the tank is higher than the second liquid level (which is higher than the first liquid level), or if the elapsed time since the start of the second tank circulation operation control reaches a second predetermined time, the second tank circulation operation control is terminated and the first tank circulation operation control is started.

2. The microbubble generator according to claim 1, characterized in that, The gas introduction mechanism is positioned upstream of the tank circulation pump in the tank circulation path.

3. The microbubble generator according to claim 1 or 2, characterized in that, The gas inlet valve is configured to be closed by a force in the direction of the liquid in the pressure reducing section. The control device is configured such that when the first tank circulation operation control ends and the second tank circulation operation control begins, the tank circulation pump is continuously driven while the rotational speed of the tank circulation pump is reduced from the first rotational speed to the second rotational speed, and then the gas inlet valve is closed.

4. The microbubble generator according to claim 1 or 2, characterized in that, The gas inlet valve is configured to be closed by a force in the direction of the liquid in the pressure reducing section. The control device is configured such that when the second tank circulation operation control ends and the first tank circulation operation control begins, the gas inlet valve is opened while the tank circulation pump is continued to be driven, and thereafter the rotational speed of the tank circulation pump is increased from the second rotational speed to the first rotational speed.

5. The microbubble generator according to claim 1 or 2, characterized in that, The liquid is water. The liquid tank is a bathtub used by users for bathing.

Images