Hot water storage type water heater

Abstract

To provide a hot water storage type water heater that makes it possible to expect the effect of inclusion of highly concentrated oxygen microbubbles on a user, and also makes it possible to remove scale in a hot water storage tank when it is used for hot water supply.SOLUTION: In a hot water storage type water heater according to the present invention, a microbubble generator 81 is provided in water pipes 42 and 71 for introducing stored hot water into a hot water storage tank 30, an air supply flow passage 83 is provided in the microbubble generator 81, an oxygen generator for generating highly concentrated oxygen air having higher oxygen concentration than that of air in the atmosphere is provided in the air supply flow passage 83, and the air generated by the oxygen generator 84 is supplied to the microbubble generator 81.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a hot water storage type water heater equipped with a hot water storage tank.

Background Art

[0002] Patent Document 1 proposes a water heater capable of efficiently diffusing fine bubbles in a bathtub. As described in Non-Patent Document 1, the International Organization for Standardization (ISO) defines bubbles with a diameter of less than 100 μm as fine bubbles. Among them, bubbles with a diameter of 1 μm or more and less than 100 μm are called microbubbles, and bubbles with a diameter of less than 1 μm are called ultra-fine bubbles. The smaller the bubble diameter, the longer the fine bubbles stay in water, and they have physiological activity effects such as blood flow promotion and sterilization, and can also perform water purification, wastewater treatment, and cleaning. In Patent Document 2, high-concentration oxygen is supplied to a bathtub as fine bubbles using an oxygen enrichment membrane.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, fine bubbles can be supplied to the bathtub, but in a storage water heater, there is also use at a water supply faucet other than the bathtub. In the oxygen-enriched membrane disclosed in Patent Document 2, there was a problem that only air with an oxygen concentration of 30% could be obtained, and it was difficult to obtain the effect of fine bubbles. In addition, in a storage water heater, scale easily adheres to the hot water storage tank, the boiling-up circuit, etc. In the supply of fine bubbles to the bathtub described in Patent Document 1 and Patent Document 2, there was a problem that fine bubbles were not supplied to the flow path where scale easily adheres, such as the hot water storage tank and the boiling-up circuit.

[0006] Therefore, an object of the present invention is to provide a storage water heater that can be expected to have an effect on the user by containing high-concentration oxygen fine bubbles when used for water supply, and can also remove scale in the hot water storage tank.

Means for Solving the Problems

[0007] The storage water heater of the present invention according to claim 1 is a storage water heater including a hot water storage tank 30 for storing hot water, a boiling-up circuit 40 for boiling up the stored hot water in the hot water storage tank 30, a water supply circuit 50 for supplying the stored hot water in the hot water storage tank 30 for water supply, and a water supply circuit 70 for supplying water to the hot water storage tank 30, wherein a fine bubble generator 81 is provided in the water pipes 42 and 71 for introducing the stored hot water into the hot water storage tank 30, an air supply flow path 83 is provided in the fine bubble generator 81, and an oxygen generator for generating high-concentration oxygen air having a higher oxygen concentration than the air in the atmosphere is provided in the air supply flow path 83, and the air generated by the oxygen generator 84 is supplied to the fine bubble generator 81. The storage water heater of the present invention according to claim 2 is the storage water heater according to claim 1, wherein the boiling-up circuit 40 includes a boiling-up water pipe 42 that leads out low-temperature water from the lower part of the hot water storage tank 30 to generate high-temperature water by the heat source unit 2 and returns the generated high-temperature water to the hot water storage tank 30, and the boiling-up water pipe 42 is used as the water pipe, and the fine bubble generator 81 is provided in the boiling-up water pipe 42. The storage - type water heater of the present invention according to claim 3 is the storage - type water heater according to claim 2, wherein the micro - bubble generator 81 is provided in the boiling hot - water pipe 42 on the upstream side of the heat source unit 2. The storage - type water heater of the present invention according to claim 4 is the storage - type water heater according to claim 2, wherein the micro - bubble generator 81 is provided in the boiling hot - water pipe 42 on the downstream side of the heat source unit 2. The storage - type water heater of the present invention according to claim 5 is the storage - type water heater according to claim 1, wherein the water supply circuit 70 includes a water supply pipe 71 connecting the water supply pipe 5 and the lower part of the hot - water storage tank 30, and the water supply pipe 71 is used as the water pipe, and the micro - bubble generator 81 is provided in the water supply pipe 71. The storage - type water heater of the present invention according to claim 6 is the storage - type water heater according to claim 5, wherein the water supply pipe 71 is provided with a pressure - reducing valve 72, and the micro - bubble generator 81 is provided in the water supply pipe 71 on the upstream side of the pressure - reducing valve 72. The storage - type water heater of the present invention according to claim 7 is the storage - type water heater according to claim 5, wherein the water supply pipe 71 is provided with a pressure - reducing valve 72, and the micro - bubble generator 81 is provided in the water supply pipe 71 on the downstream side of the pressure - reducing valve 72. The storage - type water heater of the present invention according to claim 8 is the storage - type water heater according to any one of claims 1 to 7, wherein the oxygen generator 84 includes at least two or more adsorption cylinders 87a, 87b filled with an adsorbent 86 that selectively adsorbs nitrogen rather than oxygen, an air compressor 88 for supplying compressed air to the adsorption cylinders 87a, 87b, and a flow - path switching valve 89 for switching the flow path to the adsorption cylinders 87a, 87b, and the high - concentration oxygen - rich air is supplied to the air supply flow path 83. The hot water storage type water heater of the present invention according to claim 9 is the hot water storage type water heater according to any one of claims 1 to 7, wherein the oxygen generator 84 includes an adsorption cylinder 97 filled with an adsorbent 85 that selectively adsorbs nitrogen rather than oxygen, an air compressor 87 for supplying compressed air to the adsorption cylinder 97, an oxygen tank 98 for storing the high-concentration oxygen air obtained by supplying the compressed air to the adsorption cylinder 97, a check valve 99 provided between the adsorption cylinder 97 and the oxygen tank 98, and an on-off valve 100 for discharging the compressed air in the adsorption cylinder 97, and is characterized in that the high-concentration oxygen air stored in the oxygen tank 90 is supplied to the air supply passage 83.

Advantages of the Invention

[0008] According to the present invention, when used for supplying hot water, it is possible to expect the effect of containing high-concentration oxygen microbubbles on the user, and it is also possible to remove the scale in the hot water storage tank.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0010] The hot water storage type water heater according to the first embodiment of the present invention is provided with a fine bubble generator in a water pipe that introduces stored hot water into a hot water storage tank, an air supply passage is provided in the fine bubble generator, and an oxygen generator that generates high-concentration oxygen air having a higher oxygen concentration than the air in the atmosphere is provided in the air supply passage, and the air generated by the oxygen generator is supplied to the fine bubble generator. According to the present embodiment, when used for supplying hot water, it is possible to expect an effect of containing high-concentration oxygen fine bubbles for the user, and it is also possible to remove scale in the hot water storage tank.

[0011] The second embodiment of the present invention is the hot water storage type water heater according to the first embodiment, in which the boiling-up circuit includes a boiling-up water pipe that draws out low-temperature water from the lower part of the hot water storage tank, generates high-temperature water in a heat source unit, and returns the generated high-temperature water to the hot water storage tank. Using the boiling-up water pipe as the water pipe, a fine bubble generator is provided in the boiling-up water pipe. According to the present embodiment, it is possible to remove not only the scale in the hot water storage tank but also the scale in the heat source unit.

[0012] The third embodiment of the present invention is the hot water storage type water heater according to the second embodiment, in which the fine bubble generator is provided in the boiling-up water pipe upstream of the heat source unit. According to the present embodiment, by providing the fine bubble generator in the boiling-up water pipe through which low-temperature water flows, it is possible to use a fine bubble generator having low heat resistance.

[0013] The fourth embodiment of the present invention is the hot water storage type water heater according to the second embodiment, in which the fine bubble generator is provided in the boiling-up water pipe downstream of the heat source unit. According to the present embodiment, by providing the fine bubble generator in the boiling-up water pipe through which high-temperature water flows, it is possible to increase the amount of bubble generation.

[0014] The fifth embodiment of the present invention is a storage-type water heater according to the first embodiment, in which the water supply circuit includes a water supply pipe connecting the water supply pipe and the lower part of the hot water storage tank, and a fine bubble generator is provided in the water supply pipe with the water supply pipe as the water pipe. According to this embodiment, not only the scale in the hot water storage tank but also the scale in the boiling-up circuit and the hot water supply circuit can be removed.

[0015] The sixth embodiment of the present invention is a storage-type water heater according to the fifth embodiment, in which the water supply pipe is provided with a pressure reducing valve, and the fine bubble generator is provided in the water supply pipe upstream of the pressure reducing valve. According to this embodiment, since high-concentration oxygen fine bubbles are generated using the water supply before being depressurized, the generation amount of high-concentration oxygen bubbles can be increased.

[0016] The seventh embodiment of the present invention is a storage-type water heater according to the fifth embodiment, in which the water supply pipe is provided with a pressure reducing valve, and the fine bubble generator is provided in the water supply pipe downstream of the pressure reducing valve. According to this embodiment, since the water supply that has been depressurized to a constant pressure is introduced into the fine bubble generator, a fine bubble generator with low pressure resistance can be used.

[0017] The eighth embodiment of the present invention is a storage-type water heater according to the first to seventh embodiments, in which the oxygen generator includes at least two or more adsorption cylinders filled with an adsorbent that selectively adsorbs nitrogen rather than oxygen, an air compressor for supplying compressed air to the adsorption cylinders, and a flow path switching valve for switching the flow path to the adsorption cylinders, and supplies high-concentration oxygen air to the air supply flow path. According to this embodiment, by switching the flow path from the adsorption cylinder with the flow path switching valve, the adsorption and desorption of the adsorbent are performed due to the pressure fluctuation in the adsorption cylinder, and by switching the adsorption cylinder connected to the air supply flow path, high-concentration oxygen air can be supplied to the air supply flow path.

[0018] The ninth embodiment of the present invention is a stored hot water supply machine according to the first to seventh embodiments. The oxygen generator includes an adsorption cylinder filled with an adsorbent that selectively adsorbs nitrogen rather than oxygen, an air compressor for supplying compressed air to the adsorption cylinder, an oxygen tank for storing high-concentration oxygen air obtained by supplying compressed air to the adsorption cylinder, a check valve provided between the adsorption cylinder and the oxygen tank, and an open valve for discharging the compressed air in the adsorption cylinder. The high-concentration oxygen air stored in the oxygen tank is supplied to the air supply flow path. According to this embodiment, by varying the pressure in the adsorption cylinder by the operation of the open valve, the adsorption and desorption of the adsorbent are performed, and high-concentration oxygen stored in the oxygen tank is supplied to the air supply flow path, so that high-concentration oxygen air can be supplied to the air supply flow path.

Example

[0019] Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a stored hot water supply machine according to this example. The stored hot water supply machine of this example is composed of a hot water storage unit 1 and a heat source unit 2. In this example, a heat pump unit is used as the heat source unit 2, and the heat pump unit 2 includes a heat pump circuit 20. The heat pump circuit 20 connects a compressor 21 that compresses a refrigerant and discharges a high-temperature refrigerant, a water-cooled refrigerant heat exchanger 22 that exchanges heat between water and the high-temperature refrigerant to generate hot water, a decompression device 23 that decompresses the refrigerant, and an evaporator 24 that exchanges heat between air and the refrigerant with a refrigerant pipe 25. Note that a plate heat exchanger or a double-pipe heat exchanger can be used for the water-cooled refrigerant heat exchanger 22.

[0020] The hot water storage unit 1 includes a hot water storage tank 30 for storing hot water, a boiling-up circuit 40 for boiling up the stored hot water in the hot water storage tank 30, a hot water supply circuit 50 for supplying the stored hot water in the hot water storage tank 30, a supplementary heating circuit 60 for supplementary heating the hot water in the bathtub 3 using the stored hot water in the hot water storage tank 30, and a water supply circuit 70 for supplying water to the hot water storage tank 30.

[0021] The hot water storage tank 30 is of the stacked boiling-up type. During the boiling-up operation, hot water is stacked at the upper part, cold water at the lower part, and medium-temperature water in the middle part. A hot water outflow pipe 31 is connected to the upper part of the hot water storage tank 30, and a water supply pipe 71 is connected to the lower part of the hot water storage tank 30.

[0022] The boiling-up circuit 40 connects a boiling-up pump 41, a water-cooling medium heat exchanger 22, and the hot water storage tank 30 with a boiling-up water pipe 42. By driving the boiling-up pump 41, cold water is sent from the hot water storage tank 30 to the water-cooling medium heat exchanger 22, and heat is absorbed from the refrigerant in the water-cooling medium heat exchanger 22 to generate hot water. The hot water generated in the water-cooling medium heat exchanger 22 is returned to the hot water storage tank 30. A three-way valve 43 is provided in the boiling-up water pipe 42. The hot water generated in the water-cooling medium heat exchanger 22 is returned to the upper part or the lower part of the hot water storage tank 30 by switching the three-way valve 43. During the initial boiling-up operation or the freeze prevention operation when there is almost no hot water in the hot water storage tank 30, the three-way valve 43 is switched so as to guide hot water to the hot water storage tank 30, and during the normal boiling-up operation, hot water is guided to the upper part of the hot water storage tank 30.

[0023] The hot water supply circuit 50 connects the hot water outflow pipe 31 and the hot water supply faucet 4 with a hot water supply pipe 51. A hot water supply mixing valve 53 is provided in the hot water supply pipe 51. The hot water supply mixing valve 53 mixes the hot water from the hot water storage tank 30 and the cold water from the water supply pipe 71 to obtain the required hot water supply temperature.

[0024] The reheating circuit 60 connects the hot water outflow pipe 31, a water-water heat exchanger 61, a reheating pump 62, and the middle part of the hot water storage tank 30 with a reheating water pipe 63. By driving the reheating pump 62, hot water is sent from the hot water outflow pipe 31 to the water-water heat exchanger 61, heat is dissipated in the water-water heat exchanger 61 to become medium-temperature water, and the medium-temperature water is returned to the middle part of the hot water storage tank 30. The water-water heat exchanger 61 is supplied with low-temperature bathtub water through a bathtub water circulation pipe 65 provided with a circulation pump 64. The bathtub water that has absorbed heat in the water-water heat exchanger 61 is returned to the bathtub 3 through the bathtub water circulation pipe 65.

[0025] The water supply circuit 70 connects a water pipe 5 extending from a water supply source and the lower part of the hot water storage tank 30 with a water supply pipe 71. When the stored water in the hot water storage tank 30 decreases, water is supplied from the water supply pipe 71. Also, the required low-temperature water is supplied to the hot water mixing valve 53 from the water supply pipe 71. A low-temperature water branch pipe 55 for hot water supply branched from the water supply pipe 71 and a high-temperature water branch pipe 54 for hot water supply branched from the high-temperature water outflow pipe 31 are connected to the hot water mixing valve 53, and the mixed water flowing out from the hot water mixing valve 53 is led to the hot water supply faucet 4 through the hot water supply pipe 51.

[0026] Also, the required low-temperature water is supplied to the bathtub mixing valve 68 from the water supply pipe 71. A high-temperature water branch pipe 66 for bathtub hot water supply branched from the high-temperature water outflow pipe 31 and a low-temperature water branch pipe 67 for bathtub hot water supply branched from the water supply pipe 71 are connected to the bathtub mixing valve 68, and the mixed water flowing out from the bathtub mixing valve 68 is led to the bathtub 3 through the bathtub hot water supply pipe 69. The bathtub hot water supply pipe 69 is provided with a bathtub hot water supply valve 69a. When the bathtub hot water supply valve 69a is opened, the mixed water mixed to the bathtub temperature set by the bathtub mixing valve 68 is led to the bathtub 3 through the bathtub hot water supply pipe 69. The water supply pipe 71 is provided with a pressure reducing valve 72 that reduces the pressure of tap water to a predetermined pressure.

[0027] In this embodiment, a fine bubble generator 81 is provided in a water pipe (boiling water supply pipe) 42 for introducing stored hot water into the hot water storage tank 30. The boiling water supply pipe 42 draws low-temperature water from the lower part of the hot water storage tank 30, generates high-temperature water with the heat pump unit 2, and introduces the generated high-temperature water into the hot water storage tank 30. An air supply passage 83 is provided in the fine bubble generator 81. An oxygen generator 84 is provided in the air supply passage 83. Therefore, high-concentration oxygen-enriched air generated by the oxygen generator 84 is supplied to the fine bubble generator 81. In the fine bubble generator 81, high-concentration oxygen-enriched air is supplied to generate high-concentration oxygen fine bubbles. High-concentration oxygen-enriched air is air with a higher oxygen concentration than the air in the atmosphere.

[0028] According to this embodiment, since the stored hot water containing high-concentration oxygen fine bubbles in the hot water storage tank 30 is led out from the high-temperature water outflow pipe 31 to the hot water supply faucet 4, when it is used for hot water supply, the effect of containing high-concentration oxygen fine bubbles on the user can be expected, and the scale in the hot water storage tank 30 can also be removed by the stored hot water containing high-concentration oxygen fine bubbles in the hot water storage tank 30. Also, according to this embodiment, since the fine bubble generator 81 is provided in the boiling water supply pipe 42, not only the scale in the hot water storage tank 30 but also the scale in the heat source unit 2 can be removed. When the heat pump unit 2 is used as in this embodiment, the scale in the water-cooled refrigerant heat exchanger 22 can be removed. Also, in this embodiment, the fine bubble generator 81 is provided in the boiling water supply pipe 42 on the upstream side of the heat pump unit 2. In this way, by providing the fine bubble generator 81 in the boiling water supply pipe 42 through which low-temperature water flows, a fine bubble generator 81 with low heat resistance can be used. In this embodiment, a second fine bubble generator 82 is provided in the hot water supply pipe 51 constituting the hot water supply circuit 50. Therefore, when it is used for hot water supply, the effect of containing fine bubbles on the user can be further enhanced.

[0029] FIG. 2 is a configuration diagram of a storage-type water heater according to another embodiment of the present invention. For parts other than the installation position of the fine bubble generator 81, since they are the same as the hot water storage unit 1 and the heat source unit 2 shown in FIG. 1, the same reference numerals are given and part of the description is omitted.

[0030] In this embodiment, a fine bubble generator 81 is provided in a water pipe (boiling-up water pipe) 42 for introducing stored hot water into the hot water storage tank 30. The boiling-up water pipe 42 draws out low-temperature water from the lower part of the hot water storage tank 30, generates high-temperature water with the heat pump unit 2, and introduces the generated high-temperature water into the hot water storage tank 30. According to this embodiment, since the stored hot water containing high-concentration oxygen fine bubbles in the hot water storage tank 30 is led out from the high-temperature water outflow pipe 31 to the hot water supply faucet 4, when it is used for hot water supply, the effect of containing high-concentration oxygen fine bubbles on the user can be expected, and the scale in the hot water storage tank 30 can also be removed by the stored hot water containing high-concentration oxygen fine bubbles in the hot water storage tank 30. Also, according to this embodiment, since the fine bubble generator 81 is provided in the boiling-up water pipe 42, not only the scale in the hot water storage tank 30 but also the scale in the heat source unit 2 can be removed. When the heat pump unit 2 is used as in this embodiment, the scale in the water-cooled medium heat exchanger 22 can be removed. Also in this embodiment, the fine bubble generator 81 is provided in the boiling-up water pipe 42 on the downstream side of the heat pump unit 2. Thus, by providing the fine bubble generator 81 in the boiling-up water pipe 42 through which high-temperature water flows, the amount of bubble generation can be increased. In this embodiment, a second fine bubble generator 82 is provided in the hot water supply pipe 51 constituting the hot water supply circuit 50. Therefore, when it is used for hot water supply, the effect of containing fine bubbles on the user can be further enhanced.

[0031] FIG. 3 is a configuration diagram of a stored hot water type hot water supply apparatus according to still another embodiment of the present invention. For parts other than the installation position of the fine bubble generator 81, since they are the same as the hot water storage unit 1 and the heat source unit 2 shown in FIG. 1, the same reference numerals are given and part of the description is omitted.

[0032] In this embodiment, a fine bubble generator 81 is provided in a water pipe (feed water pipe) 71 for introducing stored hot water into the hot water storage tank 30. The feed water pipe 71 introduces the supply water from the water supply pipe 5 to the lower part of the hot water storage tank 30. According to this embodiment, since the supply water containing high-concentration oxygen fine bubbles is introduced into the hot water storage tank 30, the scale in the hot water storage tank 30 can be removed by the stored hot water containing high-concentration oxygen fine bubbles, and when the stored hot water containing high-concentration oxygen fine bubbles is led out from the hot water storage tank 30, the scale in the boiling-up circuit 40, the hot water supply circuit 50, and the afterburning circuit 60 can also be removed. When the heat pump unit 2 is used as in this embodiment, the scale in the water-cooled refrigerant heat exchanger 22 can be removed. Also in this embodiment, the fine bubble generator 81 is provided in the feed water pipe 71 on the upstream side of the pressure reducing valve 72. Thus, since high-concentration oxygen fine bubbles are generated using the feed water before being depressurized, the amount of generated bubbles can be increased. In this embodiment, a second fine bubble generator 82 is provided in the hot water supply pipe 51 constituting the hot water supply circuit 50. Therefore, when used for hot water supply, the effect of containing fine bubbles on the user can be further enhanced.

[0033] FIG. 4 is a configuration diagram of a stored hot water type water heater according to still another embodiment of the present invention. Except for the installation position of the fine bubble generator 81, it is the same as the hot water storage unit 1 and the heat source unit 2 shown in FIG. 1, so the same reference numerals are given and a part of the description is omitted.

[0034] In this embodiment, a fine bubble generator 81 is provided in a water pipe (feed water pipe) 71 for introducing stored hot water into the hot water storage tank 30. The feed water pipe 71 introduces the supply water from the water supply pipe 5 to the lower part of the hot water storage tank 30. According to this embodiment, since the supply water containing high-concentration oxygen microbubbles is introduced into the hot water storage tank 30, the scale in the hot water storage tank 30 can be removed by the hot water containing high-concentration oxygen microbubbles, and by discharging the hot water containing high-concentration oxygen microbubbles from the hot water storage tank 30, the scale in the boiling-up circuit 40, the hot water supply circuit 50, and the afterburning circuit 60 can also be removed. When the heat pump unit 2 is used as in this embodiment, the scale in the water-cooled refrigerant heat exchanger 22 can be removed. In this embodiment, the microbubble generator 81 is provided in the water supply pipe 71 on the downstream side of the pressure reducing valve 72. Thus, since the water supply that has been depressurized to a constant pressure is introduced into the microbubble generator 81, a microbubble generator with low pressure resistance can be used. In this embodiment, a second microbubble generator 82 is provided in the hot water supply pipe 51 that constitutes the hot water supply circuit 50. Therefore, when used for hot water supply, the effect of containing microbubbles on the user can be further enhanced.

[0035] In addition, by providing the microbubble generator 81 shown in FIG. 3 or FIG. 4 together with the microbubble generator 81 shown in FIG. 1 or FIG. 2, the scale removal effect in the hot water storage unit 1 and the heat source unit 2 can be further enhanced. Further, the microbubble generator 81 and the second microbubble generator 82 preferably generate ultra-fine bubbles with a bubble diameter of less than 1 μm and fine bubbles with a bubble diameter of less than 100 μm, and it is suitable to use a Venturi-type generator that utilizes turbulent flow or the shear force of the flow.

[0036] FIG. 5 is a configuration diagram of an oxygen generator suitable for the embodiment of the present invention. The arrow shown in FIG. 5 indicates the air flow in operation A described below. In this embodiment, the oxygen generator 84 includes at least two or more adsorption cylinders 87a, 87b, an air compressor 88, a flow path switching valve 89, a high-concentration oxygen air circuit 90, throttle valves 91a, 91b, and a flow control valve 92, and is connected to the air supply flow path 83. The adsorption cylinders 87a and 87b are filled with a water adsorbent 85 that adsorbs moisture in the air and an adsorbent 86 that selectively adsorbs nitrogen rather than oxygen, inside the respective adsorption cylinders 87a and 87b. The water adsorbent 85 is arranged upstream of the adsorbent 86. The air compressor 88 supplies compressed air to the adsorption cylinders 87a and 87b. The flow path switching valve 89 switches between the flow path to the adsorption cylinder 87a and the flow path to the adsorption cylinder 87b. The high-concentration oxygen air circuit 90 connects the outlets of the adsorption cylinders 87a and 87b and the air supply flow path 83. The throttle valves 91a and 91b are provided in the high-concentration oxygen air circuit 90. The throttle valve 91a is arranged at the outlet of the adsorption cylinder 87a, and the throttle valve 91b is arranged at the outlet of the adsorption cylinder 87b. The flow control valve 92 adjusts the flow rate of the high-concentration oxygen air passing through the high-concentration oxygen air circuit 90. The flow path switching valve 89 has a supply port 93 connected to the air compressor 88, an adsorption cylinder a port 94 connected to the adsorption cylinder 87a, an adsorption cylinder b port 95 connected to the adsorption cylinder 87b, and exhaust ports 96a and 96b. In operation A, the flow path switching valve 89 communicates the supply port 93 and the adsorption cylinder a port 94, and communicates the adsorption cylinder b port 95 and the exhaust port 96b. Also, in operation B, the flow path switching valve 89 communicates the supply port 93 and the adsorption cylinder b port 95, and communicates the adsorption cylinder a port 94 and the exhaust port 96a. In this way, the flow path switching valve 89 performs the switching operation between operation A and operation B. In the state of operation A, the air compressed by the air compressor 88 is supplied to the adsorption cylinder 87a. The water adsorbent 85 adsorbs the moisture contained in the compressed air supplied to the adsorption cylinder 87a. The adsorbent 86 adsorbs the nitrogen contained in the compressed air supplied to the adsorption cylinder 87a. Therefore, in the state of operation A, high-concentration oxygen air is supplied from the adsorption cylinder 87a to the high-concentration oxygen air circuit 90. The high-concentration oxygen air supplied to the high-concentration oxygen air circuit 90 is sent to the air supply flow path 83 via the flow control valve 92 and is also supplied to the adsorption cylinder 87b via the throttle valve 91b. In the state of operation B, the air compressed by the air compressor 88 is supplied to the adsorption cylinder 87b. The water adsorbent 85 adsorbs the moisture contained in the compressed air supplied to the adsorption cylinder 87b. The adsorbent 86 adsorbs the nitrogen contained in the compressed air supplied to the adsorption cylinder 87b. Therefore, in the state of operation B, high-concentration oxygen air is supplied from the adsorption cylinder 87b to the high-concentration oxygen air circuit 90. The high-concentration oxygen air supplied to the high-concentration oxygen air circuit 90 is sent to the air supply passage 83 via the flow control valve 92 and is also supplied to the adsorption cylinder 87a via the throttle valve 91a. In the state of operation A, the nitrogen adsorbed on the adsorbent 86 in the adsorption cylinder 87b and the moisture adsorbed on the water adsorbent 85 in the adsorption cylinder 87b are released by the high-concentration oxygen air supplied to the adsorption cylinder 87b via the throttle valve 91b. The nitrogen and moisture released in the adsorption cylinder 87b are discharged to the atmosphere from the exhaust port 96b. In the state of operation B, the nitrogen adsorbed on the adsorbent 86 in the adsorption cylinder 87a and the moisture adsorbed on the water adsorbent 85 in the adsorption cylinder 87a are released by the high-concentration oxygen air supplied to the adsorption cylinder 87a via the throttle valve 91a. The nitrogen and moisture released in the adsorption cylinder 87a are discharged to the atmosphere from the exhaust port 96a. By repeating operation A and operation B at a predetermined timing, high-concentration oxygen air can be continuously supplied to the air supply passage 83.

[0037] As the water adsorbent 85, an adsorbent that adsorbs and desorbs moisture such as activated alumina, zeolite, or a polymer adsorbent can be used. As the adsorbent 86, an adsorbent that selectively adsorbs nitrogen rather than oxygen, such as zeolite or activated carbon, is suitably used.

[0038] FIG. 6 is an oxygen generator suitable for an embodiment of the present invention and is a configuration diagram of an oxygen generator different from FIG. 5. The oxygen generator 84 includes an adsorption cylinder 97, an air compressor 88, an oxygen tank 98, a check valve 99, and an on-off valve 100, and is connected to the air supply passage 83. The adsorption cylinder 97 is filled with an adsorbent 85 that selectively adsorbs nitrogen rather than oxygen. The air compressor 88 supplies compressed air to the adsorption cylinder 97. The oxygen tank 98 stores the high-concentration oxygen air obtained by supplying compressed air to the adsorption cylinder 97. The check valve 99 is provided in the air passage between the adsorption cylinder 97 and the oxygen tank 98. The check valve 99 prevents the backflow of the high-concentration oxygen air from the adsorption tank 98 to the adsorption cylinder 97. The on-off valve 100 discharges the compressed air in the adsorption cylinder 97. When the on-off valve 100 is closed, the air compressed by the air compressor 88 is supplied to the adsorption cylinder 97. The water adsorbent 85 adsorbs the moisture contained in the compressed air supplied to the adsorption cylinder 97. The adsorbent 86 adsorbs the nitrogen contained in the compressed air supplied to the adsorption cylinder 97. Therefore, when the on-off valve 100 is closed, the high-concentration oxygen air is sent to the oxygen tank 98 through the check valve 99. The high-concentration oxygen air stored in the oxygen tank 98 can be continuously supplied to the air supply passage 83. By opening the on-off valve 100 at a predetermined timing, the compressed air in the adsorption cylinder 97 is discharged to the atmosphere through the check valve 100. When the pressure in the adsorption cylinder 97 is released, the nitrogen adsorbed by the adsorbent 86 and the moisture adsorbed by the water adsorbent 85 can be desorbed.

[0039] Figures 7 and 8 are an example showing the scale removal effect by high-concentration oxygen microbubbles. In order to evaluate the scale removal effect of high-concentration oxygen microbubbles, a slide glass test piece was used, and a scale test piece was prepared by applying calcium carbonate scale water adjusted to a hardness of 400 ppm with calcium chloride reagent and sodium bicarbonate reagent on the surface of the test piece and drying it at 80°C. As the test water, A) tap water, B) microbubble water, and C) high-concentration oxygen microbubble water were used. The test water was put into a water bath with a stirrer, and the stirrer was stirred at 40°C and 1000 rpm. The scale test piece was installed on the wall surface of the water bath with a stirrer. After 5 minutes, the scale test piece was taken out, and the scale remaining on the scale test piece was confirmed. In order to confirm the scale remaining on the test piece, the scale test piece was immersed in a 10% indigo carmine solution, the scale was colored and photographed, and then the blue b value was measured using a color difference meter, and the residual rate was calculated with the initial value as 1. As shown in FIGS. 7 and 8, C) the high-concentration oxygen micro-bubble water has less scale residue than A) the hot water supply and B) the micro-bubble water. By using the high-concentration oxygen micro-bubble water of the present invention, the scale on the flow paths where scale easily adheres, such as not only the bathtub but also the hot water storage tank and the boiling-up circuit, can be removed.

[0040] [Configuration supported by the above embodiments] The above embodiments support the following configurations.

[0041] (Configuration 1) A hot water storage type water heater comprising a hot water storage tank for storing hot water, a boiling-up circuit for boiling up the stored hot water in the hot water storage tank, a hot water supply circuit for supplying the stored hot water in the hot water storage tank for hot water supply, and a water supply circuit for supplying water to the hot water storage tank, wherein a micro-bubble generator is provided in a water pipe for introducing the stored hot water into the hot water storage tank, an air supply flow path is provided in the micro-bubble generator, and an oxygen generator for generating high-concentration oxygen air having a higher oxygen concentration than the air in the atmosphere is provided in the air supply flow path, and the air generated by the oxygen generator is supplied to the micro-bubble generator. According to this configuration, when used for hot water supply, the effect of containing high-concentration oxygen micro-bubbles can be expected for the user, and the scale in the hot water storage tank can also be removed.

[0042] (Configuration 2) The boiling-up circuit includes a boiling-up water pipe for deriving low-temperature water from the lower part of the hot water storage tank, generating high-temperature water in a heat source unit, and returning the generated high-temperature water to the hot water storage tank. The boiling-up water pipe is used as the water pipe, and the micro-bubble generator is provided in the boiling-up water pipe. The hot water storage type water heater according to Configuration 1, characterized in that. According to this configuration, not only the scale in the hot water storage tank but also the scale in the heat source unit can be removed.

[0043] (Configuration 3) The hot water storage type water heater according to Configuration 2, characterized in that the micro-bubble generator is provided in the boiling-up water pipe upstream of the heat source unit. According to this configuration, by providing the fine bubble generator in the boiling water pipe through which cold water flows, an oxygen fine bubble generator with low heat resistance can be used.

[0044] (Configuration 4) The storage type water heater according to Configuration 2, characterized in that the fine bubble generator is provided in the boiling water pipe on the downstream side of the heat source unit. According to this configuration, by providing the fine bubble generator in the boiling water pipe through which hot water flows, the amount of oxygen bubble generation can be increased.

[0045] (Configuration 5) The storage type water heater according to any one of Configurations 1 to 4, characterized in that the water supply circuit includes a water supply pipe connecting the water supply pipe and the lower part of the hot water storage tank, and the fine bubble generator is provided in the water supply pipe with the water supply pipe as the water pipe. According to this configuration, not only the scale in the hot water storage tank but also the scale in the boiling circuit and the hot water supply circuit can be removed.

[0046] (Configuration 6) The storage type water heater according to Configuration 5, characterized in that the water supply pipe is provided with a pressure reducing valve, and the fine bubble generator is provided in the water supply pipe on the upstream side of the pressure reducing valve. According to this configuration, since high-concentration oxygen fine bubbles are generated using the water supply before being depressurized, the amount of bubble generation can be increased.

[0047] (Configuration 7) The storage type water heater according to Configuration 5, characterized in that the water supply pipe is provided with a pressure reducing valve, and the fine bubble generator is provided in the water supply pipe on the downstream side of the pressure reducing valve. According to this configuration, since the water supply depressurized to a constant pressure is introduced into the fine bubble generator, an oxygen fine bubble generator with low pressure resistance can be used.

[0048] (Configuration 8) The oxygen generator is provided with at least two or more adsorption cylinders filled with an adsorbent that selectively adsorbs nitrogen rather than oxygen, an air compressor for supplying compressed air to the adsorption cylinders, and a flow path switching valve for switching the flow path to the adsorption cylinders, and supplies the high-concentration oxygen air to the air supply flow path. The hot water storage type water heater according to any one of Configurations 1 to 7. According to this configuration, by switching the flow path from the adsorption cylinder with the flow path switching valve, the adsorption and desorption of the adsorbent are performed due to the pressure fluctuation in the adsorption cylinder, and the high-concentration oxygen air can be supplied to the air supply flow path by switching the adsorption cylinder connected to the air supply flow path.

[0049] (Configuration 9) The oxygen generator is provided with an adsorption cylinder filled with an adsorbent that selectively adsorbs nitrogen rather than oxygen, an air compressor for supplying compressed air to the adsorption cylinder, an oxygen tank for storing the high-concentration oxygen air obtained by supplying the compressed air to the adsorption cylinder, a check valve provided between the adsorption cylinder and the oxygen tank, and an on-off valve for discharging the compressed air in the adsorption cylinder, and supplies the high-concentration oxygen air stored in the oxygen tank to the air supply flow path. The hot water storage type water heater according to any one of Configurations 1 to 7. According to this configuration, by varying the pressure in the adsorption cylinder by the operation of the open / close valve, the adsorption and desorption of the adsorbent are performed, and by supplying the high-concentration oxygen air stored in the oxygen tank to the air supply flow path, high-concentration oxygen can be continuously supplied to the air supply flow path.

Industrial Applicability

[0050] According to the present invention, the scale in the hot water storage tank can also be removed.

Explanation of Signs

[0051] 1 Hot water storage unit 2 Heat pump unit (heat source unit) 3 Bathtub 4 Hot water faucet 5 Water supply pipe 20 Heat pump circuit 21 Compressor 22 Water-cooled refrigerant heat exchanger 23 Pressure reducing device 24 Evaporator 25 Refrigerant piping 30 Hot water storage tank 31 High-temperature water outlet piping 40 Boiling-up circuit 41 Boiling-up pump 42 Boiling-up water piping (water piping) 43 Three-way valve 50 Hot water supply circuit 51 Hot water supply piping 53 Hot water supply mixing valve 54 High-temperature water branch piping for hot water supply 55 Low-temperature water branch piping for hot water supply 60 Afterburning circuit 61 Water-water heat exchanger 62 Afterburning pump 63 Afterburning water piping 64 Circulation pump 65 Bathtub water circulation piping 66 High-temperature water branch piping for bathtub hot water supply 67 Low-temperature water branch piping for bathtub hot water supply 68 Bathtub mixing valve 69 Bathtub hot water supply piping 69a Bathtub hot water supply valve 70 Water supply circuit 71 Water supply piping (water piping) 72 Pressure reducing valve 81 Microbubble generator 83 Air supply flow path 84 Oxygen generator 85 Water adsorbent 86 Adsorbent 87a, 87b Adsorption cylinder 88 Air compressor 89 Flow path switching valve 90 High-concentration oxygen air circuit 97 Adsorption cylinder 98 Oxygen tank 99 Check valve 100 On-off valve

Claims

1. A hot water storage tank for storing hot water, a boiling-up circuit for boiling up the stored hot water in the hot water storage tank, a hot water supply circuit for supplying the stored hot water in the hot water storage tank, and a water supply circuit for supplying water to the hot water storage tank A hot water storage type water heater comprising: a fine bubble generator is provided in a water pipe for introducing the stored hot water into the hot water storage tank, an air supply passage is provided in the fine bubble generator, an oxygen generator for generating high-concentration oxygen air having an oxygen concentration higher than that of air in the atmosphere is provided in the air supply passage, and the air generated by the oxygen generator is supplied to the fine bubble generator A hot water storage type water heater characterized by the above.

2. The boiling-up circuit includes a boiling-up water pipe that draws low-temperature water from the lower part of the hot water storage tank, generates high-temperature water by a heat source unit, and returns the generated high-temperature water to the hot water storage tank. The boiling-up water pipe is used as the water pipe, and the fine bubble generator is provided in the boiling-up water pipe. The hot water storage type water heater according to claim 1, characterized in that

3. The hot water storage type water heater according to claim 2, characterized in that the fine bubble generator is provided in the boiling-up water pipe upstream of the heat source unit.

4. The hot water storage type water heater according to claim 2, characterized in that the fine bubble generator is provided in the boiling-up water pipe downstream of the heat source unit.

5. The water supply circuit includes a water supply pipe connecting a water supply pipe and the lower part of the hot water storage tank. The water supply pipe is used as the water pipe, and the fine bubble generator is provided in the water supply pipe. The hot water storage type water heater according to claim 1, characterized in that

6. The water supply pipe is provided with a pressure reducing valve, and the fine bubble generator is provided in the water supply pipe upstream of the pressure reducing valve. The hot water storage type water heater according to claim 5, characterized in that

7. The water supply pipe is provided with a pressure reducing valve, and the fine bubble generator is provided in the water supply pipe downstream of the pressure reducing valve. The hot water storage type water heater according to claim 5, characterized in that

8. The oxygen generator includes at least two or more adsorption cylinders filled with an adsorbent that selectively adsorbs nitrogen rather than oxygen, an air compressor for supplying compressed air to the adsorption cylinders, and a flow path switching valve for switching the flow path to the adsorption cylinders. The hot water storage type water heater according to any one of claims 1 to 7, characterized in that the high-concentration oxygen air is supplied to the air supply passage.

9. The oxygen generator includes an adsorption cylinder filled with an adsorbent that selectively adsorbs nitrogen rather than oxygen, an air compressor for supplying compressed air to the adsorption cylinder, an oxygen tank for storing the high-concentration oxygen air obtained by supplying the compressed air to the adsorption cylinder, a check valve provided between the adsorption cylinder and the oxygen tank, and an on-off valve for discharging the compressed air in the adsorption cylinder, and supplies the high-concentration oxygen air stored in the oxygen tank to the air supply flow path. The hot water storage type water heater according to any one of claims 1 to 7, characterized in that.

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