JP7035337B2 - Sterilizer and water heater - Google Patents

Description

The present invention relates to a sterilizer and a water heater.

Products that use water have concerns about the growth of bacteria in water. Therefore, as sterilization in water, heat treatment or chemical addition is generally performed, and ultraviolet rays are also widely used as sterilization means. Ultraviolet rays act on nucleic acids, which are the protoplasm of bacteria, and deprive them of their ability to grow. Therefore, they are less susceptible to the dependence of the effect depending on the type of bacteria, and are an effective bactericidal means. On the other hand, since high output is required for ultraviolet sterilization and high output ultraviolet rays have an influence on the human body, there are problems that power consumption is high and the device becomes large for protection. To solve such a problem, Patent Document 1 below proposes a means for improving sterilization efficiency by using ultraviolet rays and ozone in combination.

Japanese Unexamined Patent Publication No. 2016-2009848

In the apparatus of Patent Document 1, there is a concern that not only ultraviolet rays but also the oxidizing power of ozone accelerates the deterioration of peripheral members. In addition, there is a problem of consuming electric power due to ozone generation.

The present invention has been made to solve the above-mentioned problems, and is a sterilizer capable of increasing the sterilization efficiency in a water channel by using ultraviolet rays having a relatively low irradiation intensity, and a hot water supply equipped with the sterilizer. The purpose is to provide the device.

The sterilizing device according to the present invention is a sterilizing device including an ultraviolet irradiation unit that faces the water flow of a water channel and irradiates the water of the water flow with ultraviolet rays, and a fine bubble generating unit located upstream of the ultraviolet irradiation unit. The generating portion has an inlet portion, an intake portion, a fixed blade provided inside the inlet portion, a reduced diameter portion on the downstream side of the inlet portion, and a bubble generating portion on the downstream side of the reduced diameter portion. With an ejector structure, the reduced diameter portion is formed concentrically with the inlet portion so that its inner diameter gradually decreases toward the downstream, and the bubble generating portion gradually expands its inner diameter toward the downstream. In addition, it is formed concentrically with the reduced diameter portion, and the fixed blade is configured to generate a swirling water flow that swirls around the center of the water channel, and the fine bubble generating portion takes in air due to the negative pressure generated in the reduced diameter portion. The gas supplied through the section is sheared and crushed by a swirling water flow to generate fine bubbles in the bubble generating section. The fine bubbles include bubbles having a diameter of 50 μm or less and are bacteria. And when the swirling water stream containing fine bubbles is sterilized by irradiating the swirling water flow with ultraviolet rays from the ultraviolet irradiation part, the void ratio between the fine bubble generation part and the ultraviolet irradiation part is 0.01 or more and 0.05 or less. The optical axis of the emission bundle of ultraviolet rays emitted from the ultraviolet irradiation unit is parallel to the longitudinal direction of the water channel, and the light beam corresponding to the optical axis travels from the downstream side to the upstream side of the water channel. ..
Further, the hot water supply device according to the present invention is provided with the above-mentioned sterilization device.

According to the present invention, it is possible to improve the sterilization efficiency in the waterway by using ultraviolet rays having a relatively low irradiation intensity.

It is sectional drawing which shows the sterilizer according to Embodiment 1. FIG. It is sectional drawing which shows the modification of the sterilizer according to Embodiment 1. FIG. It is sectional drawing which shows the other modification of the sterilizer according to Embodiment 1. FIG. It is sectional drawing which shows the sterilizer according to Embodiment 2. FIG. It is sectional drawing which shows the modification of the sterilizer according to Embodiment 2. FIG. It is sectional drawing which shows the other modification of the sterilizer by Embodiment 2. FIG. It is a graph which shows the example of the relationship between the void ratio between a fine bubble generation part and an ultraviolet irradiation part, and sterilization efficiency. It is a figure which shows the hot water supply apparatus by Embodiment 3. FIG. It is a figure which shows the hot water supply apparatus by Embodiment 4. FIG. It is a figure which shows the hot water supply apparatus by Embodiment 5. It is a figure which shows the hot water supply apparatus by Embodiment 6.

Hereinafter, embodiments will be described with reference to the drawings. Common or corresponding elements in the drawings are designated by the same reference numerals to simplify or omit duplicate descriptions. The present disclosure may include any combination of the configurations described below that can be combined.

Embodiment 1.
FIG. 1 is a cross-sectional view showing a sterilizer 19 according to the first embodiment. As shown in FIG. 1, the sterilizer 19 according to the first embodiment includes an ultraviolet irradiation unit 80. The ultraviolet irradiation unit 80 faces the water flow flowing through the water channel 43 and irradiates the water in the water flow with ultraviolet rays.

Next, the operation will be described. When a water flow pump (not shown) connected to the water channel 43 is operated, a water flow is generated in the water channel 43. The arrow A1 in FIG. 1 indicates the direction in which ultraviolet rays are emitted from the ultraviolet irradiation unit 80. The arrow A2 in FIG. 1 indicates the direction of the water flow in the water channel 43. The direction of this water flow can be considered to correspond to the direction along the longitudinal direction of the channel 43 or the direction parallel to the longitudinal direction of the channel 43. The direction in which ultraviolet rays are emitted from the ultraviolet irradiation unit 80 (arrow A1) faces the direction of water flow in the water channel 43 (arrow A2).

The ultraviolet irradiation unit 80 has an emission surface 80a. Ultraviolet rays are emitted from the emission surface 80a into the water channel 43. The exit surface 80a faces the direction of the water flow (arrow A2) in the water channel 43. The ultraviolet rays emitted from the emission surface 80a of the ultraviolet irradiation unit 80 may include ultraviolet rays emitted in a direction other than the arrow A1. For example, the ultraviolet rays from the ultraviolet irradiation unit 80 may include ultraviolet rays emitted in the direction of the arrow A2 or the arrow A3 in FIG.

Microorganisms such as bacteria (hereinafter, simply referred to as "bacteria") contained in the water in the water channel 43 are killed or inactivated by the ultraviolet rays from the ultraviolet irradiation unit 80 (hereinafter, referred to as "sterilization"). ..

It is desirable that the pipe forming the water channel 43 in the range where the ultraviolet rays from the ultraviolet irradiation unit 80 may hit is configured as follows. It is desirable that the pipe be made of a material having UV resistance and water resistance. For example, it is desirable that the pipe is composed of at least a part of polytetrafluoroethylene. Polytetrafluoroethylene not only has excellent UV resistance, but also reflects UV rays. By forming the inner wall surface of the pipe with polytetrafluoroethylene, the ultraviolet rays from the ultraviolet irradiation unit 80 are reflected by the inner wall surface, and the ultraviolet rays can be irradiated to a range farther from the ultraviolet irradiation unit 80. .. The entire pipe may be made of the above-mentioned material, or only the inner wall surface of the pipe may be covered with the above-mentioned material.

The ultraviolet irradiation unit 80 includes an ultraviolet light source 39 and a light guide body 40. The ultraviolet light source 39 is turned on by the electric power supplied from the power supply unit 42. The ultraviolet light source 39 emits ultraviolet rays. It is desirable that the wavelength of the ultraviolet light emitted by the sterilizer 19 includes a wavelength in the range of 200 nm to 350 nm. Ultraviolet rays having a wavelength of 200 nm to 350 nm not only act on nucleic acids, which are the protoplasm of bacteria, to deprive them of their ability to grow, but also have the effect of destroying the protoplasm and killing the bacteria. Therefore, the bactericidal effect can be further improved by irradiating with ultraviolet rays having such a wavelength. The ultraviolet light source 39 in the present embodiment is an ultraviolet LED using a light emitting diode. The ultraviolet light source 39, which is an ultraviolet LED, is turned on by a direct current supplied from the power supply unit 42. The ultraviolet light source 39 in the present invention may be something other than an ultraviolet LED. For example, the ultraviolet light source 39 may be a low pressure mercury lamp. When the ultraviolet light source 39 is a low-voltage mercury lamp, an AC power source is used instead of the power source unit 42.

The ultraviolet light source 39 is arranged on the side surface of the straight pipe portion of the pipe forming the water channel 43. The material of the light guide body 40 has ultraviolet transparency. At least a part of the light guide body 40 may be configured to diffuse ultraviolet rays. The light guide body 40 may include at least one of a portion that directly transmits ultraviolet rays and a portion that reflects ultraviolet rays. The ultraviolet rays emitted from the ultraviolet light source 39 are incident on the light guide body 40. An exit surface 80a is formed on the light guide body 40. The ultraviolet rays incident on the light guide body 40 are guided to the emission surface 80a and are emitted from the emission surface 80a into the water channel 43. The light guide body 40 projects from the side surface portion of the water channel 43 toward the center portion of the water channel 43. The exit surface 80a is located at the center of the water channel 43.

FIG. 2 is a cross-sectional view showing a modified example of the sterilizer 19 according to the first embodiment. The modified example sterilizer 19 shown in FIG. 2 includes an ultraviolet irradiation unit 81 instead of the ultraviolet irradiation unit 80. The ultraviolet irradiation unit 81 has an emission surface 81a formed on the light guide body 40. The exit surface 81a faces the direction of the water flow (arrow A2) in the water channel 43. The arrow A5 in FIG. 2 indicates the direction in which ultraviolet rays are emitted from the emission surface 81a of the ultraviolet irradiation unit 81. The direction in which ultraviolet rays are emitted from the ultraviolet irradiation unit 81 (arrow A5) faces the direction of the water flow in the water channel 43 (arrow A2). The amount of protrusion of the light guide body 40 from the side surface portion of the water channel 43 in this modification is smaller than that in the example of FIG. 1, and does not reach the central portion of the water channel 43. Therefore, since the pressure loss due to the light guide body 40 is smaller than that in the example of FIG. 1, the flow path resistance of the water channel 43 can be reduced.

FIG. 3 is a cross-sectional view showing another modification of the sterilizer 19 according to the first embodiment. The modified example sterilizer 19 shown in FIG. 3 includes an ultraviolet irradiation unit 82 instead of the ultraviolet irradiation unit 80. The ultraviolet irradiation unit 82 has an emission surface 82a formed on the diffusion lens 41. The exit surface 82a faces the direction of the water flow (arrow A2) in the water channel 43. The diffuser lens 41 diffuses the ultraviolet rays emitted from the ultraviolet light source 39. The arrow A6 in FIG. 3 indicates the direction in which ultraviolet rays are emitted from the emission surface 82a of the ultraviolet irradiation unit 82. The direction in which ultraviolet rays are emitted from the ultraviolet irradiation unit 82 (arrow A6) faces the direction of the water flow in the water channel 43 (arrow A2). The water channel 43 of the sterilizer 19 according to this modification has a bent portion 43a that bends in an L shape. The ultraviolet irradiation portion 82 is arranged in the bending portion 43a. The exit surface 82a forms a surface continuous with the inner wall surface of the water channel 43 of the bent portion 43a. In this modification, since the ultraviolet irradiation unit 82 does not protrude into the water channel 43, the pressure loss is small and the flow path resistance of the water channel 43 can be reduced. A part of the ultraviolet rays emitted from the emission surface 82a is applied to the flow path 43b on the downstream side of the bent portion 43a, for example, as shown by an arrow A7. Therefore, the irradiation area of ultraviolet rays is increased and the sterilization efficiency is improved. In the illustrated configuration, the bent portion 43a has an angle, but even if a smoothly curved R (R) portion is formed in the bent portion 43a, turbulence is less likely to occur in the water flow. good.

The arrow A1 in FIG. 1 corresponds to the optical axis of the ultraviolet rays emitted from the ultraviolet irradiation unit 80. This "optical axis" is a light ray corresponding to the central axis of the radiant flux emitted from the ultraviolet irradiation unit 80. For example, the direction in which the radiation intensity from the ultraviolet irradiation unit 80 is maximized may be regarded as the "optical axis". Similarly, the arrow A5 in FIG. 2 and the arrow A6 in FIG. 3 correspond to the optical axes of the ultraviolet rays emitted from the ultraviolet irradiation unit 81 and the ultraviolet irradiation unit 82, respectively.

According to this embodiment, the following effects can be obtained. Since the ultraviolet rays are irradiated while the water flow in the water channel 43 flows toward the exit surfaces 80a, 81a, 82a of the ultraviolet irradiation portions 80, 81, 82, the microorganisms contained in the water of the water flow are exposed to the ultraviolet rays for a relatively long time. Can be irradiated. Therefore, an excellent bactericidal effect can be obtained. Further, the microorganisms flowing with the water stream receive higher intensity ultraviolet rays as they approach the ultraviolet irradiation units 80, 81, 82. In this way, the bactericidal effect can be further improved by gradually increasing the intensity of the ultraviolet rays irradiated to the microorganisms. From these facts, it is possible to improve the sterilization efficiency in the waterway by using ultraviolet rays having a relatively low irradiation intensity.

As a comparative example, consider irradiating ultraviolet rays from a direction perpendicular to the direction of the water flow. When ultraviolet rays are irradiated from a direction perpendicular to the direction of the water flow, it is difficult to improve the sterilization efficiency because the microorganisms are irradiated with the ultraviolet rays only for a short time when the water flow passes in the vicinity of the ultraviolet irradiation portion. Further, when ultraviolet rays are irradiated from a direction perpendicular to the direction of the water flow, the inner wall surface facing the ultraviolet irradiation portion receives high-intensity ultraviolet rays, and the member forming the inner wall surface is liable to deteriorate. On the other hand, in the present embodiment, the intensity of the ultraviolet rays received by the inner wall surface of the water channel 43 can be reduced, and the deterioration rate of the member forming the water channel 43 can be suppressed.

The flow velocity at the center of the water channel 43 is faster than the flow velocity near the wall surface. Therefore, the number of bacteria passing through the central part of the water channel 43 per unit time unit volume is larger than that in the vicinity of the wall surface. In the case of the sterilizer 19 shown in FIG. 1 or 3, since the irradiation intensity of ultraviolet rays to the water flow flowing through the center of the water channel 43 is the highest, a large amount of bacteria can be dispersed in the region having high irradiation intensity, and the sterilization efficiency can be increased. Goes up.

Embodiment 2.
Next, the second embodiment will be described with reference to FIGS. 4 to 7, but the differences from the above-described first embodiment will be mainly described, and the elements common to or corresponding to the above-mentioned elements will be described. The same reference numerals are used to simplify or omit duplicate descriptions.

FIG. 4 is a cross-sectional view showing the sterilizer 20 according to the second embodiment. As shown in FIG. 4, the sterilizer 20 according to the second embodiment is different from the sterilizer 19 of FIG. 1 in that it includes a fine bubble generation unit 70 located upstream of the ultraviolet irradiation unit 80. The ultraviolet irradiation unit 80 irradiates the water flow including the fine bubbles from the fine bubble generation unit 70 with ultraviolet rays.

Next, the operation will be described. When a water flow pump (not shown) is operated to pass water through the water channel 43 and the fine bubble generating section 70, fine bubbles are generated in the fine bubble generating section 70. The arrow A2 in FIG. 4 indicates the direction of the water flow from the fine bubble generating portion 70. It can be considered that the direction of the water flow from the fine bubble generating portion 70 corresponds to the direction along the longitudinal direction of the water channel 43 or the direction parallel to the longitudinal direction of the water channel 43. The direction in which ultraviolet rays are emitted from the ultraviolet irradiation unit 80 (arrow A1) faces the direction of water flow from the fine bubble generation unit 70 (arrow A2).

FIG. 5 is a cross-sectional view showing a modified example of the sterilizer 20 according to the second embodiment. The modified example sterilizer 20 shown in FIG. 5 is different from the sterilizer 19 of FIG. 2 in that it includes a fine bubble generating unit 70 located upstream of the ultraviolet irradiation unit 81.

FIG. 6 is a cross-sectional view showing another modification of the sterilizer 20 according to the second embodiment. The modified example sterilizer 20 shown in FIG. 6 is different from the sterilizer 19 of FIG. 3 in that it includes a fine bubble generating unit 70 located upstream of the ultraviolet irradiation unit 82.

As shown in FIG. 4, the fine bubble generating section 70 includes an ejector structure including an inlet section 71, an intake section 73, a fixed wing 74, a diameter reducing section 75, and a bubble generating section 76. A cylindrical water channel is formed inside the inlet portion 71. The reduced diameter portion 75 forms a water channel on the downstream side of the inlet portion 71. The reduced diameter portion 75 is formed concentrically with the inlet portion 71. The inner diameter of the reduced diameter portion 75 gradually decreases toward the downstream. The bubble generation portion 76 forms a flow path on the downstream side of the reduced diameter portion 75. The bubble generating portion 76 is formed concentrically with the reduced diameter portion 75. The inner diameter of the bubble generating portion 76 gradually expands toward the downstream.

A fixed wing 74 is provided upstream of the reduced diameter portion 75. The fixed wing 74 corresponds to a swirling water flow generating means that generates a swirling water flow swirling around the center of the water channel. Negative pressure is generated at the reduced diameter portion 75. Due to this negative pressure, air is supplied into the fine bubble generating section 70 through the intake section 73. The supplied air is sheared and crushed by a swirling water flow, and fine bubbles are generated in the bubble generation unit 76. The smaller the diameter of the generated fine bubbles, the more preferable. The generated fine bubbles preferably include bubbles having a diameter of 50 μm or less. The surface of fine bubbles of 50 μm or less is negatively charged. Bacteria in water that are positively charged are easily adsorbed on the surface of fine bubbles. In the waterway, the flow velocity in the central part is high and the flow velocity in the vicinity of the wall surface is slow, so that impurities such as bacteria are likely to be distributed in the vicinity of the wall surface. Since the buoyancy of fine bubbles having a diameter of 50 μm or less is small, they are uniformly dispersed in the water channel. Therefore, bacteria adhering to the surface of fine bubbles can also be uniformly dispersed in the water channel.

In the present embodiment, the following effects can be obtained by providing the swirling water flow generating means. Since the swirling water stream is irradiated with ultraviolet rays, the bacteria pass through the sterilizer 20 while swirling with the swirling water stream. As a result, the ultraviolet irradiation time and irradiation efficiency for sterilization are increased, so that high sterilization efficiency can be obtained. In the present embodiment, the fine bubble generating section 70 is provided with the swirling water flow generating means, but even when the swirling water flow generating means is provided without the fine bubble generating section, the same effect as described above can be obtained.

Further, it is known that fine particles having a diameter of the order of μm or less are scattered in the omnidirectional direction when they receive light having a short wavelength such as ultraviolet rays. In the present embodiment, the fine bubbles dispersed in the flow path are irradiated with ultraviolet rays, and the ultraviolet rays are scattered in the entire peripheral direction of the fine bubbles, so that the uniformity of the distribution of the irradiation intensity in the entire flow path is enhanced. be able to. Therefore, it is possible to sterilize the water passing through the water channel by using the ultraviolet light source 39 having a relatively low power consumption. In addition, since the intensity of ultraviolet rays can be relatively low, it is possible to suppress the deterioration rate of peripheral members such as pipes in a range where ultraviolet rays may hit.

If the diameter of the bubble is too large, it will not be scattered all around, and the area behind the bubble irradiated with ultraviolet rays will be a shadow and the ultraviolet rays will not reach. If the fine bubbles have a diameter of 50 μm or less, the ultraviolet rays can be scattered with higher efficiency, and it is possible to more reliably suppress the occurrence of a range in which the ultraviolet rays do not reach as a shadow.

The amount of fine bubbles generated by the fine bubble generation unit 70 can be expressed by the void ratio. For example, if there is a gas phase portion having a total volume of 500 mL in 10 L of water containing fine bubbles, the void ratio is 0.05. The void ratio can be calculated, for example, based on the volumetric flow rate of water flowing into the inlet portion 71 of the fine bubble generating portion 70 and the volumetric flow rate of gas passing through the intake portion 73.

FIG. 7 is a graph showing an example of the relationship between the void ratio between the fine bubble generating section 70 and the ultraviolet irradiation section 80, 81, 82 and the sterilization efficiency. In the example shown in FIG. 7, the sterilization efficiency is maximized in the range of the void ratio of about 0.01 to 0.05. If the void ratio is too high, the sterilization efficiency may be reduced by increasing the area behind the UV-irradiated bubbles that the UV light does not reach. Therefore, the void ratio when irradiating ultraviolet rays from the ultraviolet irradiation units 80, 81, 82 is preferably 0.1 or less, more preferably 0.05 or less. Further, if the void ratio is too low, the effect of diffusing ultraviolet rays by fine bubbles cannot be sufficiently obtained, and the sterilization efficiency may decrease. Therefore, the void ratio when irradiating ultraviolet rays from the ultraviolet irradiation units 80, 81, 82 is preferably 0.005 or more, and more preferably 0.01 or more.

In the sterilizer 20 of FIG. 4, the optical axis of the ultraviolet rays emitted from the ultraviolet irradiation unit 80 passes through the internal space of the bubble generation unit 76 of the fine bubble generation unit 70. That is, the extension line of the arrow A1 in FIG. 4 passes through the internal space of the bubble generation section 76 of the fine bubble generation section 70. By arranging the ultraviolet irradiation unit 80 in this way, the ultraviolet rays from the ultraviolet irradiation unit 80 can be irradiated to the fine bubbles with higher efficiency.

Similarly, in the sterilizer 20 of FIG. 5, the optical axis of the ultraviolet rays emitted from the ultraviolet irradiation unit 81, that is, the extension line of the arrow A5 in FIG. 5, forms the internal space of the bubble generation unit 76 of the fine bubble generation unit 70. Pass. Further, in the sterilizer 20 of FIG. 6, the optical axis of the ultraviolet rays emitted from the ultraviolet irradiation unit 82, that is, the extension line of the arrow A6 in FIG. 6, passes through the internal space of the bubble generation unit 76 of the fine bubble generation unit 70. As a result, the same effect as described above can be obtained.

Embodiment 3.
FIG. 8 is a diagram showing a water heater 1 according to the third embodiment. As shown in FIG. 8, the hot water supply device 1 includes a sterilizer 20, a heat pump unit 2, and a tank unit 3 described in the second embodiment. The heat pump unit 2 is installed outdoors. The tank unit 3 may be installed outdoors or indoors. In the illustrated configuration, the heat pump unit 2 and the tank unit 3 are separate bodies, but the heat pump unit 2 and the tank unit 3 may be integrated. The hot water supply device 1 of the third embodiment may include the sterilizer 19 described in the first embodiment instead of the sterilizer 20. The same applies to the fourth to sixth embodiments described later.

The heat pump unit 2 includes a refrigerant circuit 4. The refrigerant circuit 4 includes a compressor 5, a heat exchanger 6, a decompression device 7, an evaporator 8, and a refrigerant pipe 9. The refrigerant pipe 9 connects the compressor 5, the heat exchanger 6, the decompression device 7, and the evaporator 8 in an annular shape. The compressor 5 compresses the low-pressure refrigerant gas. The refrigerant may be, for example, one of carbon dioxide, R410A, R32, and a hydrocarbon. The heat exchanger 6 exchanges heat between water and a high-temperature and high-pressure refrigerant compressed by the compressor 5. Water becomes hot water by being heated in the heat exchanger 6. The decompression device 7 decompresses and expands the high-pressure refrigerant that has passed through the heat exchanger 6. The expansion valve may be used as the pressure reducing device 7. The evaporator 8 evaporates the low-pressure refrigerant that has passed through the decompression device 7. The evaporator 8 may evaporate the refrigerant by absorbing the heat of the outside air into the refrigerant. The low-pressure refrigerant gas vaporized by the evaporator 8 is sucked into the compressor 5.

In the tank unit 3, a hot water storage tank 10, a first pump 11, a switching valve 12, a bath heat exchanger 13, a second pump 14, a third pump 15, a pressure reducing valve 16, a hot water supply mixing valve 17, a bath mixing valve 18, A sterilizer 20 and a control device 50 are provided.

The hot water storage tank 10 can store hot water heated by the heat pump unit 2. A temperature stratification can be formed in the hot water storage tank 10 due to the difference in water density depending on the temperature. That is, in the hot water storage tank 10, the upper side is high temperature and the lower side is low temperature.

The water supply channel 21 is drawn into the tank unit 3 from the outside. Water from a water source such as a water supply flows through the water supply channel 21. The water supply channel 21 is connected to the pressure reducing valve 16 inside the tank unit 3. The pressure reducing valve 16 reduces the pressure of the water supplied from the water supply channel 21 to a predetermined pressure. The downstream of the pressure reducing valve 16 is branched into a water supply channel 22 and a water supply channel 23. The water supply channel 22 is connected to the water inlet 10a at the bottom of the hot water storage tank 10. The hot water storage tank 10 is maintained in a full state by the water flowing into the lower part of the hot water storage tank 10 through the water supply channel 21 and the water supply channel 22. A sterilizer 20 is installed at a position in the middle of the water supply channel 22. The water supply channel 23 is connected so that water can be supplied to each of the hot water supply mixing valve 17 and the bath mixing valve 18.

The water outlet 10b at the bottom of the hot water storage tank 10 is connected to the water inlet of the heat exchanger 6 in the heat pump unit 2 via the water channel 24. The first pump 11 is connected to a position in the middle of the water channel 24. The first pump 11 circulates water between the hot water storage tank 10 and the heat pump unit 2. Although the first pump 11 is built in the tank unit 3 in the illustrated configuration, the first pump 11 may be arranged in the heat pump unit 2.

The water outlet of the heat exchanger 6 is connected to the inlet of the switching valve 12 in the tank unit 3 via the water channel 25. A part of the water channel 24 and the water channel 25 passes through the outside of the heat pump unit 2 and the tank unit 3. The hot water inlet 10c at the upper part of the hot water storage tank 10 is connected to the first outlet of the switching valve 12 via the upper passage 26. The second outlet of the switching valve 12 is connected to the return port 10d of the hot water storage tank 10 via the bypass passage 27. The return port 10d is located at a position higher than the water inlet 10a and the water outlet 10b in the lower part of the hot water storage tank 10. The switching valve 12 can switch the flow path between a state in which the water channel 25 communicates with the upper passage 26 and a state in which the water channel 25 communicates with the bypass passage 27.

The hot water supply device 1 of the present embodiment can supply hot water to the bathtub 200 in the bathroom. In the following description, the hot water supplied to the bathtub 200 may be referred to as "bathtub water". The bath heat exchanger 13 is a heat exchanger for reheating the bathtub water. The bath heat exchanger 13 includes a primary side flow path and a secondary side flow path. The hot water outlet 10e at the upper part of the hot water storage tank 10 is connected to the first inlet 13a, which is the inlet of the primary side flow path of the bath heat exchanger 13, via the water channel 28. The first outlet 13b, which is the outlet of the primary side flow path of the bath heat exchanger 13, is connected to the return port 10f of the hot water storage tank 10 via the water channel 29. The return port 10f is located at a position higher than the water inlet 10a and the water outlet 10b in the lower part of the hot water storage tank 10. The second pump 14 is connected to a position in the middle of the water channel 29. The second pump 14 circulates water between the hot water storage tank 10 and the bath heat exchanger 13.

The second inlet 13c, which is the inlet of the secondary side flow path of the bath heat exchanger 13, is connected to the bathtub 200 via the water channel 30. The third pump 15 is connected to a position in the middle of the water channel 30. The second outlet 13d, which is the outlet of the secondary side flow path of the bath heat exchanger 13, is connected to the bathtub 200 via the water channel 31. The water channel 30 and the water channel 31 communicate with each other in the bathtub 200 via the bathtub adapter 210. The third pump 15 circulates bathtub water between the bathtub 200 and the bath heat exchanger 13.

The water channel 32 branches from a position in the middle of the water channel 28 and is connected so that hot water can be supplied to each of the hot water supply mixing valve 17 and the bath mixing valve 18. The hot water supply device 1 of the present embodiment can supply hot water to the hot water tap 300. The water heater 300 may be, for example, at least one of a shower in a bathroom, a faucet in a kitchen sink, and a faucet in a washroom. The water heater 300 is manually operated by the user to open the water heater 300. The water heater 300 may be one in which the user makes the sensor sensitive and automatically opens the water heater. The outlet of the hot water supply mixing valve 17 is connected to the hot water supply tap 300 via the hot water supply pipe 33. The water supply channel 34 branches from the water supply channel 21 and extends to the outside of the tank unit 3 and is connected to the hot water supply plug 300.

The outlet of the bath mixing valve 18 is connected to a position in the middle of the water channel 30 via the hot water supply pipe 35. A bath solenoid valve 38 is installed at a position in the middle of the hot water supply pipe 35. The bath solenoid valve 38 opens and closes the passage of the hot water supply pipe 35.

A plurality of temperature sensors 36 are attached to the hot water storage tank 10 at different heights. For example, the temperature sensor 36 may be arranged at a position where the volume from the upper part of the hot water storage tank 10 is 50L, 100L, 150L, 200L, or 250L. By detecting the water temperature distribution in the vertical direction with these temperature sensors 36, the hot water storage temperature and the hot water storage amount in the hot water storage tank 10 can be detected.

A temperature sensor 37 is attached to the water channel 25. The temperature sensor 37 can detect the temperature of the water heated by the heat pump unit 2. In the following description, the temperature of the water heated by the heat pump unit 2, that is, the temperature of the hot water flowing out from the heat pump unit 2 is also referred to as "heated water temperature".

The control device 50 controls various operations of the hot water supply device 1, which will be described later. Electronic devices such as actuators and sensors included in the hot water supply device 1 are connected to the control device 50. Operation of the compressor 5, decompression device 7, first pump 11, switching valve 12, second pump 14, third pump 15, hot water supply mixing valve 17, bath mixing valve 18, sterilizing device 20, bath solenoid valve 38 and the like described above. Is controlled by the control device 50. The temperature information detected by the temperature sensor 36 and the temperature sensor 37 is input to the control device 50.

The terminal device 60 is connected to the control device 50 wirelessly or by wire so as to be capable of bidirectional data communication. The terminal device 60 functions as a user interface for the hot water supply device 1. The terminal device 60 may be installed in the kitchen, for example. The terminal device 60 may be installed in the bathroom, for example. The hot water supply device 1 may include a plurality of terminal devices 60 installed at different locations. Alternatively, the terminal device 60 may be portable. The configuration is not limited to the configuration in which the terminal device 60 directly communicates with the control device 50, and the terminal device 60 may be configured to communicate with the control device 50 via another device.

The terminal device 60 includes an operation unit 61 and a display device 62. The operation unit 61 has a plurality of input switches operated by the user. By operating the operation unit 61, the user can, for example, set a hot water supply temperature, operate to supply hot water to the bathtub 200, command or reserve an operation to reheat the bathtub water, select a control mode for the heat storage operation, and so on. You can perform input operations related to such things. That is, the user can input a command regarding the operation of the hot water supply device 1 and a change of the set value to the terminal device 60. The terminal device 60 transmits the input information to the control device 50. The control device 50 controls the operation of the hot water supply device 1 according to the information received from the terminal device 60. The display device 62 is configured by using, for example, a flat display panel such as a liquid crystal display panel or an organic EL display panel. The display device 62 can display information by visually displaying characters, figures, characters, and the like. The display device 62 is an example of a notification device. The terminal device 60 may further include other notification devices such as, for example, a voice output device.

Next, the heat storage operation of the hot water supply device 1 will be described. The heat storage operation is an operation in which the hot water heated by the heat pump unit 2 is stored in the hot water storage tank 10. At the time of heat storage operation, it becomes as follows. The heat pump unit 2 and the first pump 11 are operated. The switching valve 12 is in a state of communicating the water channel 25 with the upper passage 26. The low-temperature water flowing out from the water outlet 10b at the bottom of the hot water storage tank 10 is guided to the heat exchanger 6 of the heat pump unit 2 through the water channel 24 and the first pump 11. When water is heated in the heat exchanger 6, hot water, that is, hot water is generated. This hot water flows into the upper part of the hot water storage tank 10 from the hot water inlet 10c through the water channel 25, the switching valve 12, and the upper passage 26. Hot water accumulates from top to bottom in the hot water storage tank 10.

During the heat storage operation, the control device 50 controls the heat pump unit 2 and the first pump 11 so that the temperature of the water to be heated detected by the temperature sensor 37 becomes equal to the target temperature. By controlling the operating state of at least one of the heat pump unit 2 and the first pump 11 as follows, for example, the temperature of the water to be heated can be adjusted. When the first pump 11 is controlled so that the circulating flow rate of water increases, the temperature of the water to be heated decreases. When the first pump 11 is controlled so that the circulating flow rate of water is reduced, the temperature of the water to be heated rises. When the operating speed of the compressor 5 is increased, the temperature of the water to be heated rises. When the operating speed of the compressor 5 is reduced, the temperature of the water to be heated decreases.

Immediately after starting the compressor 5 of the heat pump unit 2, the temperature of the refrigerant flowing into the heat exchanger 6 does not rise sufficiently. Therefore, immediately after starting the heat pump unit 2, the temperature of the water to be heated tends to be lower than the target temperature. Immediately after the heat pump unit 2 is started when the heat storage operation is started, the water channel 25 may be communicated with the bypass passage 27 by the switching valve 12. Then, after the temperature of the heated water detected by the temperature sensor 37 reaches the target temperature, the switching valve 12 may be switched so that the water channel 25 communicates with the upper passage 26. By doing so, it is possible to prevent water having a temperature lower than the target temperature from flowing into the upper part of the hot water storage tank 10.

Next, the operation of supplying hot water to the hot water tap 300 will be described. When the hot water tap 300 is opened by the user, the hot water supply operation to the hot water tap 300 starts. At the time of this hot water supply operation, it becomes as follows. The low temperature water supplied from the water source flows into the first inlet of the hot water supply mixing valve 17 through the water supply channel 21 and the water supply channel 23. The high-temperature water flowing out from the hot water outlet 10e at the upper part of the hot water storage tank 10 flows into the second inlet of the hot water supply mixing valve 17 through the water channel 28 and the water channel 32. At this time, the same amount of low-temperature water as the high-temperature water flowing out from the hot water outlet 10e flows into the lower part of the hot water storage tank 10 through the water supply channel 22 and the water inlet 10a. The hot water supply mixing valve 17 mixes low temperature water and high temperature water. The hot water supply mixing valve 17 can change the mixing ratio of the low temperature water and the high temperature water. The hot water generated by mixing with the hot water supply mixing valve 17 is supplied to the hot water supply tap 300 through the hot water supply pipe 33. The control device 50 controls the operation of the hot water supply mixing valve 17 so that the hot water supply temperature detected by the temperature sensor (not shown) installed in the hot water supply pipe 33 becomes equal to the target value. The target value of the hot water supply temperature may be the temperature set by the user on the terminal device 60. If the user wants to further control the temperature, he / she can operate the hot water tap 300 to mix the hot water supplied from the hot water supply pipe 33 with the low temperature water supplied from the water supply channel 34. The control device 50 may control the hot water supply operation according to the output of a sensor (not shown) that detects the flow in the hot water supply pipe 33.

Next, the hot water supply operation to the bathtub 200 will be described. When the control device 50 opens the bath solenoid valve 38, the hot water supply operation to the bathtub 200 starts. At the time of this hot water supply operation, it becomes as follows. The low temperature water supplied from the water source flows into the first inlet of the bath mixing valve 18 through the water supply channel 21 and the water supply channel 23. The high-temperature water flowing out from the hot water outlet 10e at the upper part of the hot water storage tank 10 flows into the second inlet of the bath mixing valve 18 through the water channel 28 and the water channel 32. At this time, the same amount of low-temperature water as the high-temperature water flowing out from the hot water outlet 10e flows into the lower part of the hot water storage tank 10 through the water supply channel 22 and the water inlet 10a. The bath mixing valve 18 mixes low temperature water and high temperature water. The bath mixing valve 18 can change the mixing ratio of the low temperature water and the high temperature water. The hot water produced by the mixing in the bath mixing valve 18 is injected into the bathtub 200 through the hot water supply pipe 35, the water channels 30 and 31. The control device 50 controls the operation of the bath mixing valve 18 so that the hot water supply temperature detected by the temperature sensor (not shown) installed in the hot water supply pipe 35 becomes equal to the target value. The target value of the hot water supply temperature may be the temperature set by the user on the terminal device 60.

Next, the reheating operation for the bathtub 200 will be described. The reheating operation is an operation of reheating the bathtub water. At the time of reheating operation, it becomes as follows. The second pump 14 and the third pump 15 are operated. The bathtub water of the bathtub 200 passes through the water channel 30, the third pump 15, the bath heat exchanger 13, and the water channel 31, and circulates so as to return to the bathtub 200. The high-temperature water flowing out from the hot water outlet 10e at the upper part of the hot water storage tank 10 flows into the bath heat exchanger 13 through the water channel 28. In the bath heat exchanger 13, the bath water is heated by the high temperature water. In the bath heat exchanger 13, the high-temperature water becomes medium-temperature water by being deprived of heat by the bathtub water. The medium-temperature water flowing out of the bath heat exchanger 13 flows into the hot water storage tank 10 from the return port 10f through the water channel 29 and the second pump 14. The bathtub water in the bath heat exchanger 13 corresponds to an object heated by the heat of the hot water supplied from the hot water outlet 10e of the hot water storage tank 10.

The sterilizer 20 is arranged in the middle of the water supply channel 22 connected to the water inlet 10a at the bottom of the hot water storage tank 10. The sterilizer 20 irradiates ultraviolet rays by turning on the ultraviolet light source 39 each time water passes through the water supply channel 22.

Bacteria such as Legionella may be present in the water supply channel 21 and the water supply channel 22. Legionella is a gram-negative bacillus that inhabits natural soils and freshwater. Legionella bacteria grow in the temperature range of 20 ° C to 50 ° C, and are said to grow best at around 36 ° C. Ultraviolet rays have the effect of killing microorganisms such as bacteria. In the present embodiment, the sterilizer 20 irradiates water with ultraviolet rays to sterilize microorganisms such as bacteria contained in the water. Therefore, it is possible to reduce the possibility that microorganisms including bacteria such as Legionella bacteria grow in the water in the hot water supply device 1. In the following description, microorganisms including bacteria such as Legionella may be simply referred to as "microorganisms".

In the present embodiment, the following effects can be obtained by irradiating the water before flowing into the hot water storage tank 10 from the water source with ultraviolet rays by the sterilizer 20. Since the water is irradiated with ultraviolet rays at the entrance of the hot water storage tank 10, it is easy to sterilize the entire amount of water flowing into the hot water storage tank 10. Therefore, the possibility that microorganisms grow in the hot water storage tank 10 can be further reduced.

The control device 50 supplies electric power from the power supply unit 42 to the ultraviolet light source 39 when water is flowing in the sterilizer 20, and electric power from the power supply unit 42 to the ultraviolet light source 39 when water is not flowing in the sterilizer 20. The power supply unit 42 may be controlled so as to stop the supply. By doing so, it is possible to reduce power consumption while reliably irradiating the water passing through the sterilizer 20 with ultraviolet rays. For example, the control device 50 may supply electric power from the power supply unit 42 to the ultraviolet light source 39 during the hot water supply operation to the hot water tap 300 and the hot water supply operation to the bathtub 200. Further, when the hot water storage tank 10 is filled with water at the first use after the installation of the hot water supply device 1, electric power may be supplied from the power supply unit 42 to the ultraviolet light source 39.

The sterilizer 20 and the water pipes on the upstream side and the downstream side thereof may be separably connected by a joint (not shown). When the sterilizer 20 is replaced with a new one, the sterilizer 20 can be easily removed by separating the joint.

In order to prevent the growth of microorganisms in water, it is advantageous that the temperature of water is high. Therefore, if the hot water storage temperature in the hot water storage tank 10 is high, the growth of microorganisms in the hot water storage tank 10 can be reliably prevented. On the other hand, the higher the temperature of the water to be heated, the lower the energy efficiency of the heat pump unit 2. Conversely, the lower the temperature of the water to be heated, the higher the energy efficiency of the heat pump unit 2. Therefore, in order to improve the energy efficiency of the hot water supply device 1, it is advantageous that the temperature of the water to be heated is low.

Embodiment 4.
Next, the fourth embodiment will be described with reference to FIG. 9, but the differences from the above-described third embodiment will be mainly described, and the elements common to or corresponding to the above-mentioned elements have the same reference numerals. Is added to simplify or omit duplicate explanations. FIG. 9 is a diagram showing a water heater 45 according to the fourth embodiment.

In the water heater 45 of the present embodiment shown in FIG. 9, the position of the sterilizer 20 is different from that of the water heater 1 of the second embodiment. The sterilizing device 20 included in the hot water supply device 45 is installed at a position in the middle of the water channel 24 connecting the water outlet 10b at the bottom of the hot water storage tank 10 and the water inlet of the heat exchanger 6 in the heat pump unit 2. The sterilizer 20 included in the hot water supply device 45 irradiates the water between the hot water storage tank 10 and the heat exchanger 6 in the heat pump unit 2 with ultraviolet rays.

When the first pump 11 is operated, water flows in the sterilizer 20. The control device 50 supplies electric power from the power supply unit 42 to the ultraviolet light source 39 when water is flowing in the sterilizer 20, that is, during the operation of the first pump 11, and no water is flowing in the sterilizer 20. At that time, that is, while the first pump 11 is stopped, the power supply unit 42 may be controlled so as to stop the power supply from the power supply unit 42 to the ultraviolet light source 39. By doing so, it is possible to reduce power consumption while reliably irradiating the water passing through the sterilizer 20 with ultraviolet rays.

In the present embodiment, by irradiating the water with ultraviolet rays from the sterilizer 20 during the heat storage operation, the water immediately after being irradiated with the ultraviolet rays can be heated by the heat pump unit 2. As a result, the effect of ultraviolet rays and the effect of heating are synergistic, and the growth of microorganisms in water can be reliably prevented. Instead of the configuration shown in the figure, the sterilizer 20 may be installed at a position in the middle of the water channel 25 connecting the water outlet of the heat exchanger 6 in the heat pump unit 2 and the switching valve 12. In that case, by irradiating the water with ultraviolet rays from the sterilizer 20 during the heat storage operation, the water immediately after being heated by the heat pump unit 2 can be irradiated with the ultraviolet rays. In this case as well, the synergistic effect of the ultraviolet rays and the effect of heating can surely prevent the growth of microorganisms in the water.

When the temperature of the hot water in the hot water storage tank 10 drops, microorganisms may grow in the hot water storage tank 10. In the present embodiment, when the temperature of the hot water in the hot water storage tank 10 drops, the water may be irradiated with ultraviolet rays from the sterilizer 20 while operating the first pump 11. By doing so, the water in the hot water storage tank 10 can be sterilized by ultraviolet rays, so that the possibility of microorganisms growing in the hot water storage tank 10 can be reduced.

When the heat storage operation is not necessary, the water may be irradiated with ultraviolet rays from the sterilizer 20 while operating the first pump 11 without operating the heat pump unit 2. In that case, the switching valve 12 may allow the water channel 25 to communicate with the bypass passage 27. By doing so, the water in the hot water storage tank 10 can be sterilized by ultraviolet rays while preventing the unheated water from flowing into the upper part of the hot water storage tank 10.

Embodiment 5.
Next, the fifth embodiment will be described with reference to FIG. 10, but the differences from the above-mentioned third embodiment will be mainly described, and the elements common to or corresponding to the above-mentioned elements have the same reference numerals. Is added to simplify or omit duplicate explanations. FIG. 10 is a diagram showing a water heater 46 according to the fifth embodiment.

The hot water supply device 46 of the present embodiment shown in FIG. 10 has a different position of the sterilizer 20 than the hot water supply device 1 of the third embodiment. The sterilizing device 20 included in the hot water supply device 46 is installed at a position in the middle of the water channel 28 connecting the hot water outlet 10e at the upper part of the hot water storage tank 10 and the first inlet 13a of the bath heat exchanger 13. The sterilizer 20 included in the hot water supply device 46 irradiates the water passing through the water channel 28 with ultraviolet rays.

When the second pump 14 is operated, water flows in the sterilizer 20. The control device 50 supplies electric power from the power supply unit 42 to the ultraviolet light source 39 when water is flowing in the sterilizer 20, that is, during the operation of the second pump 14, and no water is flowing in the sterilizer 20. At that time, that is, while the second pump 14 is stopped, the power supply unit 42 may be controlled so as to stop the power supply from the power supply unit 42 to the ultraviolet light source 39. By doing so, it is possible to reduce power consumption while reliably irradiating the water passing through the sterilizer 20 with ultraviolet rays.

When the reheating operation for the bathtub 200 is performed, the medium-temperature water that has passed through the bath heat exchanger 13 collects in the lower part of the hot water storage tank 10. Since the temperature of the medium-temperature water is lower than that of the high-temperature water, microorganisms may grow in the medium-temperature water collected in the lower part of the hot water storage tank 10. On the other hand, in the present embodiment, by irradiating the water with ultraviolet rays from the sterilizing device 20 during the reheating operation, the medium-temperature water accumulated in the lower part of the hot water storage tank 10 can be sterilized by ultraviolet rays. As a result, it is possible to reliably prevent the growth of microorganisms in the medium-warm water collected in the lower part of the hot water storage tank 10.

When the temperature of the hot water in the hot water storage tank 10 drops, microorganisms may grow in the hot water storage tank 10. In the present embodiment, when the temperature of the hot water in the hot water storage tank 10 drops, the water may be irradiated with ultraviolet rays from the sterilizer 20 while operating the second pump 14. By doing so, the water in the hot water storage tank 10 can be sterilized by ultraviolet rays, so that the possibility of microorganisms growing in the hot water storage tank 10 can be reduced.

Embodiment 6.
Next, the sixth embodiment will be described with reference to FIG. 11, but the differences from the above-described third embodiment will be mainly described, and the elements common to or corresponding to the above-mentioned elements have the same reference numerals. Is added to simplify or omit duplicate explanations. FIG. 11 is a diagram showing a water heater 47 according to the sixth embodiment.

The hot water supply device 47 of the present embodiment shown in FIG. 11 has a different position of the sterilizer 20 than the hot water supply device 1 of the third embodiment. The sterilizing device 20 included in the hot water supply device 47 is installed at a position in the middle of the water channel 31 connecting the second outlet 13d of the bath heat exchanger 13 and the bathtub 200. As described above, the sterilizer 20 included in the hot water supply device 47 irradiates the bathtub water passing through the water channel 31 connected to the bathtub 200 with ultraviolet rays. Instead of the configuration shown in the figure, the sterilizer 20 may be installed at a position in the middle of the water channel 30 connecting the second inlet 13c of the bath heat exchanger 13 and the bathtub 200.

When the third pump 15 is operated, bath water flows in the sterilizer 20. The control device 50 supplies electric power from the power supply unit 42 to the ultraviolet light source 39 when the bath water is flowing in the sterilizer 20, that is, during the operation of the third pump 15, and the bath water flows in the sterilizer 20. The power supply unit 42 may be controlled so as to stop the power supply from the power supply unit 42 to the ultraviolet light source 39 when the power supply unit 42 is not working, that is, while the third pump 15 is stopped. By doing so, it is possible to reduce power consumption while reliably irradiating the bathtub water passing through the sterilizer 20 with ultraviolet rays.

According to this embodiment, the bathtub water passing through the sterilizer 20 can be sterilized by ultraviolet rays. Therefore, the possibility of microorganisms growing in the water in the bathtub 200 can be reliably reduced.

In this embodiment, the sterilizer 20 is arranged inside the tank unit 3. Instead of such a configuration, the sterilizer 20 may be attached to the water channel 31 arranged in the bathroom. If the sterilizer 20 is arranged inside the tank unit 3 or in the bathroom, the work can be easily performed when the maintenance of the sterilizer 20 is required.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, the water heater may include a plurality of sterilizers installed at two or more positions in the third to sixth embodiments. Further, the sterilizer in the present invention is not limited to the one provided in the hot water supply device, and may be incorporated in, for example, a water purifier.

1 Hot water supply device, 2 Heat pump unit, 3 Tank unit, 4 Refrigerant circuit, 5 Compressor, 10 Hot water storage tank, 11 1st pump, 12 Switching valve, 13 Bath heat exchanger, 14 2nd pump, 15 3rd pump, 16 Pressure reducing valve, 17 hot water mixing valve, 18 bath mixing valve, 19, 20 sterilizer, 21, 22, 23 water supply channel, 33 hot water supply pipe, 35 hot water supply pipe, 38 bath electromagnetic valve, 39 ultraviolet light source, 40 light guide, 41 Diffusing lens, 42 power supply, 43 water channel, 43a bend, 43b flow path, 45, 46, 47 hot water supply device, 50 control device, 60 terminal device, 70 fine bubble generator, 71 inlet, 73 intake, 74 fixed Wings, 75 reduced diameter part, 76 bubble generating part, 80, 81, 82 UV irradiation part, 200 bathtub, 300 hot water tap

Claims (5)

In a sterilizer provided with an ultraviolet irradiation unit that faces the water flow of a water channel and irradiates the water of the water flow with ultraviolet rays, and a fine bubble generation unit located upstream of the ultraviolet irradiation unit.
The fine bubble generating portion is located at an inlet portion, an intake portion, a fixed wing provided inside the inlet portion, a reduced diameter portion on the downstream side of the inlet portion, and a downstream side of the reduced diameter portion. It has an ejector structure with a bubble generator and
The reduced diameter portion is formed concentrically with the inlet portion so that its inner diameter gradually decreases toward the downstream.
The bubble generating portion is formed concentrically with the reduced diameter portion so that its inner diameter gradually expands toward the downstream.
The fixed wing is configured to generate a swirling stream that swirls around the center of the channel.
In the fine bubble generation portion, the gas supplied through the intake portion is shear-crushed by the swirling water flow due to the negative pressure generated in the reduced diameter portion, so that fine bubbles are generated in the bubble generation portion. Is configured to
The fine bubbles include bubbles having a diameter of 50 μm or less.
When the swirling water stream containing bacteria and the fine bubbles is sterilized by irradiating the swirling water stream with ultraviolet rays from the ultraviolet irradiation section, the void ratio between the fine bubble generation section and the ultraviolet irradiation section is 0.01 or more. , 0.05 or less,
The optical axis of the radiant flux of ultraviolet rays emitted from the ultraviolet irradiation unit is parallel to the longitudinal direction of the water channel, and the light beam corresponding to the optical axis travels from the downstream side to the upstream side of the water channel. .. The ultraviolet irradiation unit has an exit surface from which ultraviolet rays are emitted into the water channel.
The sterilizer according to claim 1, wherein the exit surface faces the water flow. Provided with the waterway having an L-shaped bend,
The sterilizer according to claim 1 or 2, wherein the ultraviolet irradiation portion is arranged in the bent portion. The sterilizer according to any one of claims 1 to 3 , wherein the light beam corresponding to the central axis of the radiant flux emitted from the ultraviolet irradiation portion passes through the internal space of the bubble generation portion of the fine bubble generation portion. .. A water heater comprising the sterilizing device according to any one of claims 1 to 4 .

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