Solar air heater and water heater

Abstract

The utility model relates to a solar air heater and a water heater adopting the solar air heater, the solar water heater adopts hot air generated by a single-pass heat collecting pipe type solar air heater to heat feed water, and simultaneously adopts a heat storage process to realize efficient utilization of solar heat. The problem of incrustation in a solar water heater in which an existing heat collector directly heats water is solved, the technological process is simplified, installation and maintenance are convenient, the operation cost is low, and expected social and economic benefits are remarkable.

Description

Technical Field

[0001] This utility model relates to the field of solar thermal recovery technology, and in particular to a solar hot air heater and water heater using a single-pass heat collection tube. Background Technology

[0002] Solar thermal applications include solar water heating, solar heating, solar cooling, solar industrial and agricultural applications, and photovoltaic / thermal integration (PV / T) applications. According to statistics from the IEA SHC TCP, in terms of installed capacity, in 2022, residential solar thermal systems providing domestic hot water or heating for single-family homes accounted for approximately 60% of the total installed capacity of global solar thermal systems.

[0003] Taking China as an example, the annual newly added collector area and proportion of different types of solar collectors from 2004 to 2023 are shown in the attached figure. Figure 3 As shown.

[0004] Solar thermal utilization systems using the aforementioned collectors, especially in single-family homes where circulating hot water systems are the primary application, suffer from the problem of easy scale buildup on the collectors, which is difficult to remove and hard to eliminate at the source. Chinese patents such as 202110572786.4 – a scale removal device for a new energy solar water heater, 202222951988.2 – a solar water heater with a built-in scale scraping and cleaning structure, 202321328920.7 – a solar water heater tank with purification function, and 202321565698.2 – a solar water heater that facilitates scale removal, provide measures for scale removal, which have some effect. However, after a period of time, scale will reappear.

[0005] Chinese patent 202221467099.2 – A solar dual-channel collector tube type balcony water heater – achieves airflow heating through the cooperation of a manifold and solar collector tubes. A heat exchanger is installed on the circulation pipe connected at both ends of the manifold, and the heat exchanger is connected to a water tank. A circulation pump is installed on the water tank, and a fan is installed on the circulation pipe. The power for the fan and circulation pump is entirely supplied by outdoor solar photovoltaic panels. This design has fewer connection points and fewer leakage points. The circulation pump continuously heats the liquid, maintaining the water tank temperature and ensuring a continuous supply of hot water, eliminating the scale buildup problem of traditional water-heating collectors. It is undoubtedly an excellent technical solution. However, it also has certain drawbacks: scale buildup still occurs on the water side of the air-water heat exchanger, affecting the heat exchange effect.

[0006] Therefore, how to solve the scaling problem of water supply heating collectors and heat exchangers, and optimize the equipment settings of solar water heaters while ensuring safe and efficient heat transfer, is worthy of in-depth research. Summary of the Invention

[0007] The purpose of this invention is to solve the above-mentioned problems by using a single-pass heat collection tube to generate hot air, and then using the hot air as a heat source to exchange heat with the water entering the air-water heat exchanger. This produces hot water while eliminating the problem of scale buildup in traditional water supply heating type heat collection tubes.

[0008] A solar thermal air heater 7, wherein the solar thermal air heater 7 employs a single-pass heat collection tube, as shown in the attached figure. Figure 1 Appendix Figure 2 As shown, the single-pass solar collector tube adopts a three-tube structure, including a vacuum glass tube 77, an inner tube 78, an inlet branch pipe 81, a sealing element 79, an inlet main pipe 80, and a header 74. The inner tube 81, the inlet main pipe 80, the inlet branch pipes 81, and the header should preferably be made of stainless steel. The outer surface of the inner tube 78 of the single-pass solar collector tube is coated with a selective absorption coating to maximize the absorption rate of direct solar radiation and minimize infrared re-radiation. The gas is pressurized by the circulating fan 4 and enters the inlet main pipe 80, and then splits into multiple inlets. The gas branch pipe 81, located at the bottom of the inner tube 81 of the single-pass heat collector pipe, flows into the inner tube 81 of the single-pass heat collector pipe, absorbs the heat of solar energy, and the generated hot gas enters the header 74 to form hot air 76; or the gas enters the main air inlet pipe 80, and then flows into multiple air inlet branch pipes 81, located at the bottom of the inner tube 78 of the single-pass heat collector pipe, flows into the inner tube 81 of the single-pass heat collector pipe, absorbs the heat of solar energy, and the generated hot gas enters the header 74 to form hot air 76, which is then drawn out by the fan 13 for user use.

[0009] A solar water heater, as shown in the attached image Figure 2 As shown, the system includes a solar hot air heater 7, a gas-water heat exchanger 11, and a hot water tank 1. The solar hot air heater 7 uses a single-pass collector tube, which has a three-tube structure, including a vacuum glass tube 77, an inner tube 78, an air inlet branch pipe 81, a seal 79, and a header 74. Hot air 76 drawn from the header 74 is sent to the gas-water heat exchanger 11 via a fan 13 to heat the water supplied from the hot water tank 1, the circulating water pump 22, and the water supply pipeline 23. The cooled gas returns to the main air inlet pipe 80 of the solar hot air heater 7 via the return air pipe 5, then enters the air inlet branch pipe 81, and flows back into the inner tube 78 of the single-pass collector tube. The hot gas, which absorbs the heat from solar energy, enters the header 74. The water heated by the hot air in the gas-water heat exchanger 11 returns to the hot water tank 1. Alternatively, the hot air 76 drawn from the header 74 enters the gas-water heat exchanger 11 to heat the water supplied from the hot water tank 1, the circulating water pump 22, and the water supply pipeline 23. The cooled gas then returns to the main air inlet pipe 80 of the solar thermal air heater 7 via the circulating fan 4 and the return air pipe 5. It then enters the air inlet branch pipe 81 and flows back into the inner pipe 78 of the single-pass collector tube. The hot gas, which absorbs the heat from solar energy, enters the header 74. The water heated by the hot air in the gas-water heat exchanger 11 returns to the hot water tank 1.

[0010] The intake manifold 80 and the intake branch pipe 81 are connected by welding or threading.

[0011] The gas-water heat exchanger 11 is either an indirect heat exchanger (wall-type heat exchanger) or a direct heat exchanger (gas-water mixing separator).

[0012] The circulating fan 4 is equipped with an adjusting damper 3 for adjusting the air volume of the circulating fan 4.

[0013] The ventilator 13 is equipped with a hot air regulating damper 12 for adjusting the air volume of the ventilator 13.

[0014] The circulating fan 4 and the ventilation fan 13 are essentially the same, and are only distinguished by their function.

[0015] The circulating fan 4 or the ventilation fan 13 mentioned above is a centrifugal, axial, screw, or vortex fan.

[0016] The solar hot air unit 7 is equipped with necessary support rods or support frames to securely, stably, and effectively fix the solar hot air unit and prevent overturning accidents caused by strong winds.

[0017] The hot water tank 1 is equipped with an inlet valve 17, through which cold water 16 enters the hot water tank 1. The cold water 16 is tap water or groundwater.

[0018] Preferably, the inlet valve 17 is an automatic water replenishment valve. When the water level in the hot water tank 1 is at a set low level, the automatic water replenishment valve opens to allow water to enter. When the water level in the hot water tank 1 reaches a set high level, the automatic water replenishment valve closes to stop replenishing water, thereby avoiding the phenomenon of water overflow and waste caused by forgetting to close the inlet valve when replenishing water in traditional solar water heaters.

[0019] The hot water tank 1 is equipped with a hot water valve 19: the water in the hot water tank 1 is output as domestic hot water 20 through the hot water valve 19.

[0020] The hot water tank 1 is equipped with a drain valve 18, which is used to discharge the solid waste that has settled in the hot water tank 1.

[0021] The hot water tank 1 is equipped with an air inlet valve 24: the air inlet valve 24 is in the closed state when the through-collector tube solar water heater is running. When the air in the air space of the hot water tank 1 is lower than the atmospheric pressure, the air inlet valve 24 can be opened to add air, as indicated by the pressure gauge installed on the hot water tank 1. It will close when it is balanced with the external pressure, so as to avoid the phenomenon of "negative pressure collapse" of the hot water tank caused by air dissolving into water.

[0022] When the hot water tank 1 operates under positive pressure, a small amount of air will dissolve into the water and be carried out by the hot water. Air can be added through an air compressor, air storage bottle or air pump via air inlet valve 24.

[0023] The system includes a heat exchanger 27 and a heat storage unit 28. Hot air drawn from the header 74 passes through the fan 13, the heat storage pipeline valve 26, the heat exchanger 27, and the high-temperature heat storage pipeline 30 back to the main air inlet pipe 80 of the solar hot air heater 7. It then enters the air inlet branch pipe 81, flows back into the inner pipe 78 of the single-pass heat collector pipe, absorbs the heat from the solar energy, and the generated hot gas enters the header 74, thus forming a closed-loop circulation loop for heat storage air. The heat transfer medium enters the heat exchanger 27 via the booster 29 to absorb heat, returns to the heat storage unit 28 to store heat, and then returns to the booster 29, thus forming a heat transfer and heat storage circulation loop for the heat transfer medium.

[0024] The booster 29 is a hydraulic pump when the heat transfer medium is a liquid (e.g., heat transfer oil) and a gas compressor when the heat transfer medium is a gas.

[0025] The heat storage device 28 employs liquid heat storage (such as heat transfer oil), solid heat storage (such as pebbles), or phase change heat storage.

[0026] When the heat storage device 28 uses liquid heat storage, the heat transfer medium is the heat storage liquid. When supplying heat, the heat transfer medium 35 can be output through the booster 29 and the heat transfer medium valve 34 to supply heat and then return to the heat storage device 28; or it can be output through the booster 29 and the heat exchanger 27 and then return to the heat storage device 28, and indirectly supply heat through the heat exchanger 27.

[0027] When the heat storage device 28 adopts phase change or solid heat storage, the air 31 outputs heated air 33 through the heat storage device 28 and the blower 32.

[0028] When the heat storage device 28 adopts the phase change heat storage method, the phase change heat storage material is Na2CO3-BaCO3 / MgO or Na2SO4 / SiO2.

[0029] The circulating fan 4 or the ventilation fan 13 adopts a variable frequency speed regulation mode, which can flexibly adjust the air volume and air pressure when the sunlight, heating, and hot water tank temperature change.

[0030] Preferably, the hot water tank 1 is made of corrosion-resistant stainless steel.

[0031] The hot water tank 1, air-water heat exchanger 11, air pipe, and heat storage tank 28 of the single-pass collector tube solar water heater are insulated.

[0032] The through-tube solar water heater is equipped with an electric heater or a gas waste heat recovery unit, which is used as a supplementary heat source to heat water on cloudy days.

[0033] This invention is also applicable to nitrogen, argon, or a mixture of oxygen and nitrogen.

[0034] Pipelines, instruments, valves, regulating bypasses, etc., not specified in this application shall be matched with mature technologies known in solar water heating projects.

[0035] For components not mentioned in this application, such as safety accessories, interlocking protection devices, and automatic controls, existing known technologies shall be used.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] 1. Compared to existing solar water heater technology that directly heats water using collector tubes, the single-pass collector tube of this invention uses clean air that has been "washed" by water and circulated in a closed loop. This ensures a clean collector tube with efficient heat transfer, unlike collector tubes that directly heat water, which can accumulate scale, affect heat exchange, and eventually clog the collector tube. This results in extremely low maintenance costs and a significantly extended operating cycle. In winter, unlike collector tubes that directly heat water, it will not experience problems such as ice formation and blockage of the water supply pipes due to low temperatures, or cracking and leakage at the connection between the water tank and the collector tube.

[0038] 2. Compared with existing technologies for heating air and producing hot water using through-tube solar collectors (e.g., 202221467099.2 - a solar dual-tube solar collector balcony water heater), the technical solution of this application can be used to retrofit existing direct-heating solar collector balcony water heaters, which can revitalize and make good use of existing equipment and reduce investment.

[0039] 3. Compared with existing solar water heater technology that directly heats water using collector tubes, the hot water tank and fan of this invention are installed indoors, making installation, use, maintenance, and repair convenient and reducing operating costs.

[0040] 4. Compared with existing solar water heater technology that directly heats water using collector tubes, this invention can be installed on the roof or used as a wall-mounted solar water heater for a household balcony. When installed on the roof, it is lightweight and leak-proof, causing minimal damage to the roof's waterproofing layer and ensuring a high safety factor. When used as a wall-mounted solar water heater for a household balcony, it is lightweight and leak-proof, preventing any impact on downstairs residents or pedestrians due to leaks.

[0041] 5. Compared with existing collector tube solar water heater technology, this invention sets up a high-temperature heat storage and heat supply system to realize the high-temperature heat utilization of solar energy. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the main structure of a solar hot air blower according to this utility model.

[0043] Figure 1In the middle: 7-Solar hot air heater, 74-Manifold, 75-Air inlet of solar hot air heater 7, 76-Hot air, 77-Vacuum glass tube, 78-Inner tube, 79-Seal, 80-Main air inlet pipe, 81-Branch air inlet pipe.

[0044] Figure 2 This is a schematic diagram of the structure of a solar water heater according to this utility model.

[0045] Figure 2 Chinese: 1-Hot water tank, 2-Gas space, 3-Regulating damper, 4-Circulating fan, 5-Return air duct, 6-One-way valve, 7-Solar hot air heater, 11-Gas-water heat exchanger, 12-Hot air regulating damper, 13-Ventilator, 14-Hot air duct valve, 15-Hot air duct, 16-Cold water, 17-Inlet valve, 18-Drain valve, 19-Hot water valve, 20-Hot water, 21-Regulating valve, 22-Circulating water pump, 23-Water supply pipeline, 24-Inlet valve, 25-Regulating valve 26-Valve, 27-Heat exchanger, 28-Heat accumulator, 29-Booster, 30-High temperature heat storage pipeline, 31-Air, 32-Blower, 33-Heating air, 34-Heat medium valve, 35-Heating medium, 74-Manifold, 75-Inlet of solar hot air heater 7, 76-Outlet of solar hot air heater 7, 77-Vacuum glass tube, 78-Inner tube, 79-Sealing plug, 80-Main inlet pipe, 81-Branch inlet pipe, 115-Return water pipeline.

[0046] Figure 3 This is a chart showing the annual increase in collector area and percentage of different types of solar collectors in China from 2004 to 2023. Detailed Implementation

[0047] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] Example 1:

[0049] A solar thermal air heater 7, wherein the solar thermal air heater 7 employs a single-pass heat collection tube, as shown in the attached figure. Figure 1 Appendix Figure 2As shown, the single-pass solar collector tube adopts a three-tube structure, including a vacuum glass tube 77, an inner tube 78, an inlet branch pipe 81, a sealing element 79, an inlet main pipe 80, and a header 74. The inner tube 81, the inlet main pipe 80, the inlet branch pipe 81, and the header are made of stainless steel. The outer surface of the inner tube 78 of the single-pass solar collector tube is coated with a selective absorption coating to maximize the absorption rate of direct solar radiation and minimize infrared re-radiation. The gas is pressurized by the circulating fan 4 and enters the inlet main pipe 80, and then splits into multiple inlets. The gas branch pipe 81, located at the bottom of the inner tube 81 of the single-pass heat collector pipe, flows into the inner tube 81 of the single-pass heat collector pipe, absorbs the heat of solar energy, and the generated hot gas enters the header 74 to form hot air 76; or the gas enters the main air inlet pipe 80, and then flows into multiple air inlet branch pipes 81, located at the bottom of the inner tube 78 of the single-pass heat collector pipe, flows into the inner tube 81 of the single-pass heat collector pipe, absorbs the heat of solar energy, and the generated hot gas enters the header 74 to form hot air 76, which is then drawn out by the fan 13 for user use.

[0050] The intake manifold 80 and the intake branch pipe 81 are connected by welding.

[0051] Example 2:

[0052] As attached Figure 2 As shown, a solar water heater includes a solar hot air heater 7, a gas-water heat exchanger 11, and a hot water tank 1. The solar hot air heater 7 uses a single-pass collector tube, which has a three-tube structure, including a vacuum glass tube 77, an inner tube 78, an air inlet branch pipe 81, a sealing element 79, and a manifold 74. Hot air 76 drawn from the manifold 74 is sent to the gas-water heat exchanger 11 via a fan 13, a hot air pipe valve 14, and a hot air pipe 15 to heat water supplied from the hot water tank 1, a regulating valve 21, a circulating water pump 22, and a water supply pipeline 23. The cooled gas returns to the main air inlet pipe 80 of the solar hot air heater 7 via a return air pipe 5 and a one-way valve 6, then enters the air inlet branch pipe 81, and flows back into the inner tube 78 of the single-pass collector tube to absorb heat. The heat generated by solar energy enters the header 74. The water heated by the hot air in the gas-water heat exchanger 11 returns to the hot water tank 1 via the return water pipeline 115. Alternatively, the hot air 76 drawn from the header 74 enters the gas-water heat exchanger 11 via the hot air pipeline valve 14 and the hot air pipeline 15, heating the water supplied from the hot water tank 1, regulating valve 21, circulating water pump 22, and water supply pipeline 23. The cooled gas returns to the main air inlet pipe 80 of the solar hot air heater 7 via the circulating fan 4, return air pipeline 5, and one-way valve 6, then enters the air inlet branch pipe 81, and flows back into the inner pipe 78 of the single-pass collector tube to absorb the heat from solar energy. The generated hot gas enters the header 74. The water heated by the hot air in the gas-water heat exchanger 11 returns to the hot water tank 1 via the return water pipeline 115.

[0053] The intake manifold 80 and the intake branch pipe 81 are connected by welding or threading.

[0054] The gas-water heat exchanger 11 is either an indirect heat exchanger (wall-type heat exchanger) or a direct heat exchanger (gas-water mixing separator).

[0055] The circulating fan 4 is equipped with an adjusting damper 3 for adjusting the air volume of the circulating fan 4.

[0056] The ventilator 13 is equipped with a hot air regulating damper 12 for adjusting the air volume of the ventilator 13.

[0057] The circulating fan 4 and the ventilation fan 13 are essentially the same, and are only distinguished by their function.

[0058] The circulating fan 4 or the ventilation fan 13 mentioned above is a centrifugal, axial, screw, or vortex fan.

[0059] The solar hot air unit 7 is equipped with necessary support rods or support frames to securely, stably, and effectively fix the solar hot air unit and prevent overturning accidents caused by strong winds.

[0060] The hot water tank 1 is equipped with an inlet valve 17, through which cold water 16 enters the hot water tank 1. The cold water 16 is tap water or groundwater.

[0061] Preferably, the inlet valve 17 is an automatic water replenishment valve. When the water level in the hot water tank 1 is at a set low level, the automatic water replenishment valve opens to allow water to enter. When the water level in the hot water tank 1 reaches a set high level, the automatic water replenishment valve closes to stop replenishing water, thereby avoiding the phenomenon of water overflow and waste caused by forgetting to close the inlet valve when replenishing water in traditional solar water heaters.

[0062] The hot water tank 1 is equipped with a hot water valve 19: the water in the hot water tank 1 is output as domestic hot water 20 through the hot water valve 19.

[0063] The hot water tank 1 is equipped with a drain valve 18, which is used to discharge the solid waste that has settled in the hot water tank 1.

[0064] The hot water tank 1 is equipped with an air inlet valve 24: the air inlet valve 24 is in the closed state when the through-collector tube solar water heater is running. When the air in the air space of the hot water tank 1 is lower than the atmospheric pressure, the air inlet valve 24 can be opened to add air, as indicated by the pressure gauge installed on the hot water tank 1. It will close when it is balanced with the external pressure, so as to avoid the phenomenon of "negative pressure collapse" of the hot water tank caused by air dissolving into water.

[0065] When the hot water tank 1 operates under positive pressure, a small amount of air will dissolve into the water and be carried out by the hot water. Air can be added through an air compressor, air storage bottle or air pump via air inlet valve 24.

[0066] The system includes a heat exchanger 27 and a heat storage unit 28. Hot air drawn from the header 74 passes through the fan 13, the heat storage pipeline valve 26, the heat exchanger 27, the regulating valve 25, and the high-temperature heat storage pipeline 30 back to the main air inlet pipe 80 of the solar hot air heater 7. It then enters the air inlet branch pipe 81, flows back into the inner pipe 78 of the single-pass heat collector pipe, absorbs the heat from the solar energy, and the generated hot gas enters the header 74, thus forming a closed-loop circulation loop for heat storage air. The heat transfer medium enters the heat exchanger 27 via the booster 29 to absorb heat, returns to the heat storage unit 28 to store heat, and then returns to the booster 29, thus forming a heat transfer and heat storage circulation loop for the heat transfer medium.

[0067] The booster 29 is a hydraulic pump when the heat transfer medium is a liquid (e.g., heat transfer oil) and a gas compressor when the heat transfer medium is a gas.

[0068] The heat storage device 28 employs liquid heat storage (such as heat transfer oil), solid heat storage (such as pebbles), or phase change heat storage.

[0069] When the heat storage device 28 uses liquid heat storage, the heat transfer medium is the heat storage liquid. When supplying heat, the heat transfer medium 35 can be output through the booster 29 and the heat transfer medium valve 34 to supply heat and then return to the heat storage device 28; or it can be output through the booster 29 and the heat exchanger 27 and then return to the heat storage device 28, and indirectly supply heat through the heat exchanger 27.

[0070] When the heat storage device 28 adopts phase change or solid heat storage, the air 31 outputs heated air 33 through the heat storage device 28 and the blower 32.

[0071] When the heat storage device 28 adopts the phase change heat storage method, the phase change heat storage material is Na2CO3-BaCO3 / MgO or Na2SO4 / SiO2.

[0072] The circulating fan 4 or the ventilation fan 13 adopts a variable frequency speed regulation mode, which can flexibly adjust the air volume and air pressure when the sunlight, heating, and hot water tank temperature change.

[0073] Preferably, the hot water tank 1 is made of corrosion-resistant stainless steel.

[0074] The hot water tank 1, air-water heat exchanger 11, air pipe, and heat storage tank 28 of the single-pass collector tube solar water heater are insulated.

[0075] The through-tube solar water heater is equipped with an electric heater or a gas waste heat recovery unit, which is used as a supplementary heat source to heat water on cloudy days.

[0076] This invention is also applicable to nitrogen, argon, or a mixture of oxygen and nitrogen.

[0077] Pipelines, instruments, valves, regulating bypasses, etc., not specified in this application shall be matched with mature technologies known in solar water heating projects.

[0078] For components not mentioned in this application, such as safety accessories, interlocking protection devices, and automatic controls, existing known technologies shall be used.

[0079] For aspects not mentioned in this application, such as safety accessories, interlocking protection devices, and automatic controls, existing known technologies are employed. Although the present invention has been disclosed above with reference to preferred embodiments, these are not intended to limit the invention. Any person skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention, and these modifications also fall within the protection scope of the invention. Therefore, the protection scope of the present invention should be determined by the claims of this application.

Claims

1. A solar-powered hot air heater, characterized in that, The solar thermal air heater uses a single-pass heat collector tube, which has a three-tube structure, including a vacuum glass tube (77), an inner tube (78), an inlet branch pipe (81), a sealing element (79), an inlet main pipe (80), and a header (74). The outer surface of the inner tube (78) of the single-pass heat collector tube is coated with a selective absorption coating. The gas is pressurized by the circulating fan (4) and enters the inlet main pipe (80), and then flows into the inlet branch pipe (81). At the bottom of the inner tube (78) of the single-pass heat collector tube, the gas flows into the inlet main pipe (80). The gas enters the inner tube (78) of the single-pass heat collector tube, absorbs the heat of solar energy, and the generated hot gas enters the header (74) to form hot air (76) for output to users; or the gas enters the main intake pipe (80), and then flows into the intake branch pipe (81). At the bottom of the inner tube (78) of the single-pass heat collector tube, it flows back into the inner tube (78) of the single-pass heat collector tube, absorbs the heat of solar energy, and the generated hot gas enters the header (74) to form hot air (76) which is then drawn out by the fan (13) for output to users.

2. A solar water heater, characterized in that, The solar water heater includes a solar hot air blower (7), a gas-water heat exchanger (11), and a hot water tank (1). The solar hot air blower (7) adopts a single-pass heat collection tube, which has a three-tube structure, including a vacuum glass tube (77), an inner tube (78), an air inlet branch pipe (81), a sealing element (79), and a header (74). Hot air (76) drawn from the header (74) is sent to the gas-water heat exchanger (11) by a fan (13) to heat the water supplied by the hot water tank (1), the circulating water pump (22), and the water supply pipeline (23). The cooled gas returns to the main air inlet pipe (80) of the solar hot air blower (7) through the return air pipe (5), and then enters the air inlet branch pipe (81), where it flows back into the single-pass heat collection tube. The inner tube (78) absorbs the heat of the solar energy, and the generated hot gas enters the header (74). The water heated by the hot air in the gas-water heat exchanger (11) returns to the hot water tank (1). Alternatively, the hot air (76) drawn from the header (74) enters the gas-water heat exchanger (11) to heat the water sent from the hot water tank (1), the circulating water pump (22), and the water supply line (23). The cooled gas returns to the main air inlet pipe (80) of the solar hot air heater (7) via the circulating fan (4) and the return air pipe (5), and then enters the air inlet branch pipe (81). It then flows back into the inner tube (78) of the single-pass collector tube to absorb the heat of the solar energy. The generated hot gas enters the header (74), and the water heated by the hot air in the gas-water heat exchanger (11) returns to the hot water tank (1).

3. The solar water heater according to claim 2, characterized in that, The hot water tank (1) is equipped with an inlet valve (17): cold water (16) enters the hot water tank (1) through the inlet valve (17); When the inlet valve (17) is an automatic water replenishment valve, the automatic water replenishment valve opens to replenish water when the water level in the hot water tank (1) is at the set low water level, and closes to stop replenishing water when the water level in the hot water tank (1) reaches the set high water level.

4. The solar water heater according to claim 2, characterized in that, A heat exchanger (27) and a heat storage device (28) are provided: hot air drawn from the header (74) passes through the fan (13), the heat exchanger (27), and the high-temperature heat storage pipeline (30) and returns to the main air intake pipe (80) of the solar hot air heater (7), then enters the air intake branch pipe (81), flows back into the inner pipe (78) of the single-pass heat collector pipe, absorbs the heat of solar energy, and the generated hot gas enters the header (74), thus forming a closed loop of heat storage air; the heat transfer medium enters the heat exchanger (27) through the booster (29) to absorb heat, returns to the heat storage device (28), and the heat transfer medium returns to the booster (29), thus forming a heat transfer and heat storage loop of the heat transfer medium.

5. The solar water heater according to claim 4, characterized in that, The heat storage device (28) adopts liquid heat storage, solid heat storage or phase change heat storage.

6. The solar water heater according to claim 5, characterized in that, When the heat storage device (28) adopts the phase change heat storage method, the phase change heat storage material is Na2CO3-BaCO3 / MgO or Na2SO4 / SiO2.

7. The solar water heater according to claim 2, characterized in that, The circulating fan (4) or ventilation fan (13) is a centrifugal, axial, screw, or vortex fan.

8. The solar water heater according to claim 2, characterized in that, The gas-water heat exchanger (11) is a partitioned heat exchanger or a gas-water mixing separator.

9. The solar water heater according to claim 2, characterized in that, The solar water heater is equipped with an electric heater or a gas waste heat recovery unit.

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