Vacuum tube of solar water heater

Abstract

The invention relates to the field of renewable and heat energy utilization technical devices, in particular to a vacuum tube of a solar water heater, which comprises an outer tube, an inner tube is fixedly mounted at the inner end of the outer tube, a corrugated tube is arranged in the inner tube in a penetrating manner, a central tube is arranged in the corrugated tube in a penetrating manner, and a temperature control transmission device is arranged in the central tube. A center shaft is detachably and rotationally installed at the lower end of the center pipe, the inner end of the inner pipe is sleeved with a stabilizing sleeve, the stabilizing sleeve is located below the center pipe, the center shaft is arranged on the inner side of the stabilizing sleeve in a penetrating mode, a sealing plug is detachably installed at the bottom end of the inner pipe, and after a double-helix metal sheet in the center pipe is heated, a driven rod is driven to rotate. And along with rotation of the driven rod and rotation of the stabilizing disc, the stabilizing disc drives the corrugated pipe to also start to rotate in the inner pipe under the action of the connecting rod in the rotating process, so that impurities in water can be adsorbed, and meanwhile, water flow is stirred to facilitate prevention of scale deposition and flushing of formed sediments.

Description

Technical Field

[0001] The invention relates to the field of renewable and thermal energy utilization technical devices, in particular to a vacuum tube of a solar water heater. Background Art

[0002] Solar thermal utilization is an important field of renewable energy utilization, with mature technology and broad application prospects. It has obvious advantages in energy substitution, emission reduction, and safe energy use. At present, the most mature product of solar thermal utilization in my country is solar water heater. The solar water heater industry is an important emerging industry in my country with independent intellectual property rights, a complete industrial chain, a certain industrial scale and market space, and compliance with low-carbon environmental protection requirements and sustainable development.

[0003] After searching, it is found that the prior art publication number is CN103712356A, which discloses a vacuum tube of a solar water heater, including: a cover glass tube and an inner glass tube, the cover glass tube and the inner glass tube are two concentric glass tubes, there is a vacuum between the cover glass tube and the inner glass tube, a vertical partition is arranged inside the inner glass tube to divide the inner glass tube into two parts, the left part and the right part are connected through a pressure valve installed at the bottom of the vertical partition; a rotating motor is arranged at the bottom of the cover glass tube; an oscillating cleaning device, which includes a gel ball, a high-pressure water pump and a discharge pipe, the gel ball is placed at the water outlet of the high-pressure water pump, the water outlet of the high-pressure water pump is connected to the upper end of the inner glass tube, the gel ball enters the inner glass tube under the water pressure of the high-pressure water pump, and continuously hits the inner wall of the inner glass tube, and the discharge pipe is connected to the lower end of the inner glass tube. The present invention provides a vacuum tube of a solar water heater that prevents cold water from entering, avoids pipe explosion, and is easy to remove scale in the tube.

[0004] Therefore, based on the above search and in combination with the existing technology, the core component of the water heater, the vacuum tube, uses high-frequency vibration to remove scale in the tube, which will cause the glass tube to be loosened or damaged at the connection with other components through the sealing ring or rubber ring due to the vibration, resulting in seal failure. At the same time, the vibration may increase the friction between the glass tube and the bracket or other accessories, resulting in local wear and damage. Therefore, this method is not a wise choice. For this reason, we propose a vacuum tube for a solar water heater. Summary of the invention

[0005] The object of the present invention is to provide a vacuum tube for a solar water heater to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a vacuum tube of a solar water heater, comprising an outer tube, an inner tube fixedly mounted on the inner end of the outer tube, a bellows penetrated inside the inner tube, the bellows is made of breathable cotton cloth, and the cotton product has good acid and alkali resistance, a central tube penetrated inside the bellows, and a temperature control transmission device is arranged inside the central tube, a central shaft is detachably and rotatably mounted on the lower end of the central tube, a stabilizing sleeve is sleeved on the inner end of the inner tube, the stabilizing sleeve is located below the central tube, and the central shaft penetrates the inner side of the stabilizing sleeve, and a sealing plug is detachably mounted on the bottom end of the inner tube; The temperature control transmission device includes a stabilizing disk, a passive rod is fixedly installed on the bottom end of the stabilizing disk, a double-helix metal sheet that can change shape according to temperature changes is passed through the inner end of the central tube, and a connecting rod is fixedly installed on the outer surface of the bellows. The connecting rod has the function of supporting the bellows so that the bellows will not become limp when soaked in water.

[0007] As a further solution of the present invention, the connecting rod is used to provide stable support for the corrugated tube, and a stabilizing ring is fixedly installed on the bottom end of the center tube. The outer surface of the stabilizing ring is fixedly connected to the bottom end of the connecting rod, and the center axis and the stabilizing ring are on the same axis. The effect of the concentric axis makes the transmission of the device simpler and less prone to damage.

[0008] As a further solution of the present invention, a connecting ring is fixedly installed on the upper end of the double-helix metal sheet, and the lower end of the passive rod is passed through the inner end of the connecting ring, and a sealing rubber ring is arranged between the passive rod and the central tube to prevent water from seeping into the central tube, and to prevent the double-helix metal sheet from undergoing an oxidation reaction with water, which would greatly reduce its service life. At the same time, a sealing rubber ring is arranged between the passive rod and the central tube to prevent water from seeping into the central tube, and to prevent the double-helix metal sheet from undergoing an oxidation reaction with water, which would greatly reduce its service life.

[0009] As a further solution of the present invention, a limiting plate is arranged above the stabilizing disk, and a plurality of stabilizing cylinders are fixedly installed on the lower end of the limiting plate, and the stabilizing cylinders are all penetrated through the inner end of the stabilizing disk, and abutment balls are penetrated through the outer surfaces of the stabilizing cylinders, and the abutment balls are located below the stabilizing disk, and one end of the abutment balls away from the stabilizing cylinders is located on the outer surface of the stabilizing cylinders, so that the abutment balls can be stuck in the bottom end of the stabilizing disk, and a latch is provided on the inner end of the stabilizing cylinder, which thereby realizes a more stable effect of the device and avoids loosening when soaked in water.

[0010] As a further solution of the present invention, a scraper is rotatably installed on the upper end of the stabilizing sleeve, and the outer surface of the scraper is in contact with the inner wall of the inner tube. The scraper is fixedly installed on the outer surface of the central shaft, and the scraper, the stabilizing sleeve and the central shaft are on the same axis, and the central shaft is rotatably connected to the stabilizing sleeve.

[0011] As a further solution of the present invention, the inner wall of the stabilizing sleeve is provided with an annular spring piece, the outer surface of the stabilizing sleeve is provided with a plurality of holes, wall-breaking balls are provided in the holes, and an arc groove is fixedly installed on the end face of the annular spring piece close to the wall-breaking ball, the outer surface of the wall-breaking ball is in contact with the outer surface of the arc groove, and the annular ball arranged in an annular manner enables the stabilizing sleeve to be stabilized at the center of the inner tube, avoiding hard contact between the stabilizing sleeve and the inner wall of the inner tube.

[0012] As a further solution of the present invention, a trapezoidal block is provided at the inner end of the sealing plug, and the trapezoidal block becomes wider step by step from top to bottom. A plurality of locking rods are provided at the outer surface of the sealing plug, and the locking rods are arranged in a ring shape around the periphery of the sealing plug. The end surface of the locking rod away from the sealing plug is spherical, and the end of the locking rod close to the trapezoidal block contacts the slope surface of the trapezoidal block. The spherical design makes the sliding process smoother after contacting the slope surface, and isolates all hard contacts.

[0013] As a further solution of the present invention, a screw cap is rotatably mounted on the bottom end of the trapezoidal block, and the sealing plug threaded sleeve is sleeved on the outer surface of the screw cap, and the threaded connection ensures that the screw cap will not fall off easily, thereby maintaining the stability of the trapezoidal block.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. In the working process of the present invention, after the double-helix metal sheet in the central tube is heated, the characteristic of the double-helix metal sheet expanding due to heat causes the connecting ring to start rotating, thereby driving the passive rod to rotate. As the passive rod starts to rotate, it drives the stabilizing disk to rotate. Therefore, during the rotation process, the stabilizing disk drives the bellows to start rotating inside the inner tube under the action of the connecting rod, and produces a stirring effect. The adsorption capacity of cotton fibers is utilized to adsorb impurities in the water. At the same time, stirring the water flow helps to prevent scale deposition and flush away the formed sediments, thereby avoiding excessive scale adhering to the inner wall of the inner tube, causing a burden on subsequent cleaning. 2. During the use of the present invention, the stabilizing sleeve also rises. Since there is still water in the inner tube, the blades start to rotate and transmit power to the scraper through the central axis, so that the scraper also starts to rotate. The scraper can directly contact the tube wall to efficiently remove the scale attached to the inner wall of the inner tube and restore the smoothness of the inner wall of the pipe; 3. During the working process of the present invention, the double-helix metal sheet has a simple structure, low manufacturing cost, and convenient maintenance. It is widely used in various industrial and domestic environments, does not require power, and works entirely on mechanical principles, and is suitable for a variety of power-free environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of a vacuum tube of a solar water heater; Figure 2 A schematic diagram of the internal structure of a vacuum tube of a solar water heater; Figure 3 A schematic diagram of the internal partial structure of a vacuum tube of a solar water heater; Figure 4 for Figure 3 The structural diagram at A in the middle; Figure 5 It is a schematic diagram of the specific structure of the stabilizing disk; Figure 6 It is a schematic diagram of the internal structure of the stabilizing cylinder; Figure 7 It is a structural schematic diagram of a stabilizing sleeve; Figure 8 This is the disassembly diagram of the stabilizing sleeve; Fig. 9 Schematic diagram of the internal structure of the sealing plug.

[0016] In the figure: 1. outer tube; 2. inner tube; 3. bellows; 4. center tube; 31. connecting rod; 101. stabilizing disk; 102. pull ring; 103. passive rod; 104. rectangular movable groove; 105. latch; 106. stabilizing cylinder; 107. abutment ball; 108. unlocking groove; 109. limit plate; 201. stabilizing sleeve; 202. wall-breaking ball; 203. scraper; 204. center axis; 205. annular spring piece; 206. blade; 301. sealing plug; 302. screw cap; 303. handle; 304. trapezoidal block; 305. locking rod; 401. double spiral metal sheet; 402. stabilizing ring; 403. bump; 404. connecting ring. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Example 1: Please refer to Figures 1 to 3, a vacuum tube of a solar water heater, comprising an outer tube 1, an inner tube 2 is fixedly mounted on the inner end of the outer tube 1, and the outer surface of the inner tube 2 is coated with a heat-absorbing coating, such as: aluminum silicon nitride (Al-N / Al) coating, copper aluminum nitrogen (Cu-Al-N) coating, chromium (Cr) coating, titanium oxynitride (Ti-NO) coating, different layers have different functions, which are existing mature technologies, and the functions of each layer are not described in detail here, and the inner tube 2 and the outer tube 1 are both made of high borosilicate glass, which has extremely high heat resistance and very low expansion coefficient, so it is particularly suitable as the main raw material of the solar water heater, and there is a vacuum layer between the inner tube 2 and the outer tube 1, and the vacuum layer effectively reduces the heat loss and improves the heat collection efficiency; The inner tube 2 is provided with a bellows 3, which is made of breathable cotton cloth, and the cotton product has good acid and alkali resistance and is a natural material. Therefore, when the inner tube 2 is filled with water, the bellows 3 is soaked inside and has a long service life, and will not produce toxic chemical reactions with water. The bellows 3 is provided with a central tube 4, and a temperature control transmission device is provided inside the central tube 4. The lower end of the central tube 4 is detachably and rotatably installed with a central shaft 204. The inner end of the inner tube 2 is sleeved with a stabilizing sleeve 201, and the stabilizing sleeve 201 is located below the central tube 4, and the central shaft 204 is penetrated on the inner side of the stabilizing sleeve 201. There is a certain gap between the outer surface of the stabilizing sleeve 201 and the inner surface of the inner tube 2, so as to avoid direct contact between the stabilizing sleeve 201 and the inner wall of the inner tube 2, thereby avoiding hard contact and scratching the inner wall of the inner tube 2, which indirectly affects the service life of the inner tube 2. The bottom end of the inner tube 2 is detachably installed with a sealing plug 301; See also Figure 3 , 45. The temperature control transmission device includes a stabilizing disk 101, a passive rod 103 is fixedly welded to the bottom end of the stabilizing disk 101, a double-helix metal sheet 401 which can change its shape according to temperature changes is pierced through the inner end of the central tube 4, a connecting rod 31 is fixedly installed on the outer surface of the bellows 3, and the connecting rod 31 is used to provide stable support for the bellows 3, a stabilizing ring 402 is fixedly installed on the bottom end of the central tube 4, the outer surface of the stabilizing ring 402 is fixedly welded to the bottom end of the connecting rod 31, and the central axis 204 and the stabilizing ring 402 are on the same axis, the upper end of the connecting rod 31 is detachably connected to the stabilizing disk 101 by bolts, which is convenient for subsequent maintenance, the double-helix metal sheet 401 is composed of two different metal strips, and the thermal expansion coefficients of the two metals are different. Since the two metal strips are tightly combined together, the uneven thermal expansion will cause the double The spiral sheet is bent, and a connecting ring 404 is fixedly welded on the upper end of the double-helix metal sheet 401, and the lower end of the passive rod 103 is inserted into the inner end of the connecting ring 404, and a sealing rubber ring is arranged between the passive rod 103 and the central tube 4, so as to prevent water from penetrating into the central tube 4, and to prevent the double-helix metal sheet 401 from reacting with water to cause an oxidation reaction, which greatly reduces the service life. When the double-helix metal sheet 401 expands due to heat, the connecting ring 404 starts to rotate, and the expansion process of the double-helix metal sheet 401 also causes the connecting ring 404 to move up and down. Therefore, a rectangular movable groove 104 is provided on the outer surface of the passive rod 103 away from the stabilizing disk 101, and a protrusion 403 is fixedly welded on the inner end of the connecting ring 404, and the protrusion 403 is slidably installed in the rectangular movable groove 104, so as to achieve that the connecting ring 404 still does not affect the rotation of the passive rod 103 during the up and down movement; See also Figure 5 , 6 7. A limiting plate 109 is arranged above the stabilizing plate 101. A plurality of stabilizing cylinders 106 are fixedly welded to the lower end of the limiting plate 109. The stabilizing cylinders 106 are all penetrated through the inner end of the stabilizing plate 101. Abutment balls 107 are penetrated through the outer surfaces of the stabilizing cylinders 106. The abutment balls 107 are located below the stabilizing plate 101. One end of the abutment balls 107 away from the stabilizing cylinders 106 is located on the outer surface of the stabilizing cylinders 106. Therefore, the abutment balls 107 can be stuck at the bottom end of the stabilizing plate 101. The inner end is sleeved with a latch 105, and an unlocking groove 108 is provided on the outer surface below the latch 105. The unlocking groove 108 is arc-shaped, and the arc gradually increases downward and finally becomes flush with the latch 105. On the contrary, the abutment ball 107 can be completely retracted inside the unlocking groove 108, and the abutment ball 107 is elliptical and clamped on the outer surface of the stabilizing cylinder 106, so it will not break away from the restraint of the stabilizing cylinder 106. A pull ring 102 for easy grasping is provided above the limiting plate 109, and the bottom end of the pull ring 102 is fixedly welded to the upper end of the latch 105; Example 2: Please refer to Figure 8 , 9 , a vacuum tube of a solar water heater, based on Example 1, a scraper 203 is rotatably installed on the upper end of the stabilizing sleeve 201, and the outer surface of the scraper 203 is in contact with the inner wall of the inner tube 2, and the outer surface of the scraper 203 is wrapped by a silicone layer, thereby avoiding hard contact with the inner wall of the inner tube 2 and scratching the inner wall of the inner tube 2, the scraper 203 is fixedly installed on the outer surface of the central shaft 204, and the scraper 203, the stabilizing sleeve 201 and the central shaft 204 are on the same axis, and the central shaft 204 is rotatably connected to the stabilizing sleeve 201, and a blade 206 is fixedly installed on the bottom end of the central shaft 204, when the stabilizing sleeve 201 moves, under the influence of the water flow, the blade 206 starts to rotate, causing the central shaft 204 to rotate, and accompanied by As the central axis 204 rotates, the scraper 203 can clean the inner wall of the inner tube 2 while rotating. The inner wall of the stabilizing sleeve 201 is provided with an annular spring piece 205. The outer surface of the stabilizing sleeve 201 is provided with a plurality of holes. Wall-breaking balls 202 are provided in the holes. The wall-breaking balls 202 are made of hard silicone and are fixed with an arc groove on the end surface of the annular spring piece 205 close to the wall-breaking balls 202. The outer surface of the wall-breaking balls 202 is in contact with the outer surface of the arc groove. Under the elastic action of the annular spring piece 205, the wall-breaking balls 202 will shrink into the stabilizing sleeve 201 when subjected to force. At the same time, when the wall-breaking balls 202 are provided around the stabilizing sleeve 201, the stabilizing sleeve 201 can always be kept on the same axis as the inner tube 2. See also Figure 2 , 9 The inner end of the sealing plug 301 is penetrated by a trapezoidal block 304, which gradually widens from top to bottom. The outer surface of the sealing plug 301 is penetrated by a plurality of locking rods 305, which are arranged in a ring around the outer periphery of the sealing plug 301. The end surface of the locking rod 305 away from the sealing plug 301 is spherical, and one end of the locking rod 305 close to the trapezoidal block 304 contacts the slope surface of the trapezoidal block 304, thereby realizing the upward movement of the trapezoidal block 304. Under the action of the slope extrusion, the locking rod 305 moves in the direction away from the sealing plug 301, and the outer surface is wrapped by a silicone layer. An annular groove is opened at the inner lower end of the inner tube 2, and the curvature of the groove is the same as that of the sphere, so that the end of the locking rod 305 away from the sealing plug 301 can be more stably inserted into the groove; The outer surface of the sealing plug 301 is sleeved with multiple layers of sealing rubber rings to prevent water in the inner tube 2 from seeping out. The bottom end of the trapezoidal block 304 is rotatably installed with a screw cover 302, and the threaded sleeve of the sealing plug 301 is sleeved on the outer surface of the screw cover 302. Through a threaded connection, the screw cover 302 is pressed against the bottom end of the trapezoidal block 304 to prevent the trapezoidal block 304 from slipping off. The bottom end of the screw cover 302 is fixed with a handle 303 by bolts.

[0019] The working principle of the present invention is: When working, the vacuum tube absorbs solar radiation and converts it into heat energy. After the water in the inner tube 2 is absorbed, it heats up. Then, due to its low density, the hot water naturally rises to the hot water storage tank, and the cold water flows back from the bottom of the hot water storage tank to the inner tube 2, thus forming a natural convection phenomenon without the need for a water pump. Therefore, after the double helix metal sheet 401 in the central tube 4 is heated, the double helix metal sheet 401 expands when heated, causing the connecting ring 404 to start rotating, thereby driving the passive rod 103 to rotate. As the passive rod 103 starts to rotate, it drives The stabilizing disk 101 rotates, so the stabilizing disk 101 drives the bellows 3 to start rotating inside the inner tube 2 through the action of the connecting rod 31 during the rotation process, thereby achieving the effect of stirring the water inside the inner tube 2. Water will produce scale during the heating process, and the cotton bellows 3 rotates slowly in the inner tube 2. The cotton fiber has a certain adsorption capacity, thereby achieving that the scale produced by the water during the heating process can be preferentially attached to the outer surface of the bellows 3, thereby effectively slowing down the effect of scaling on the inner wall of the inner tube 2. When the solar water heater needs to be maintained and cleaned, the vacuum tube is removed from the solar water heater, but the water in the inner tube 2 will not be discharged during the drainage process of the solar water heater. Therefore, there will still be water inside the inner tube 2. Subsequently, the pull ring 102 is clamped by a tool and the pull ring 102 is pulled outward. During the upward movement of the latch 105, the bottom of the unlocking groove 108 will abut against the abutting ball 107, so that the abutting ball 107 abuts against the bottom end of the stabilizing plate 101, thereby achieving the effect of lifting the stabilizing plate 101 upward. With the rise of the bellows 3, the stabilizing sleeve 201 also rises. Because there is still water in the inner tube 2, the blade 206 starts to rotate, and transmits power to the scraper 203 through the central shaft 204, so that the scraper 203 also starts to rotate; At this time, due to the rotation of the scraper 203 and the stabilizing sleeve 201 driving the scraper 203 to rise, the scale remaining on the inner wall of the inner tube 2 is cleaned, and then the bellows 3 and the stabilizing sleeve 201 are completely pulled out of the inner tube 2, the rotary cover 302 is rotated to make the rotary cover 302 and the trapezoidal block 304 descend, and then the handle 303 is grasped to pull out the rotary cover 302 and the trapezoidal block 304, and the locking rod 305 is squeezed by the groove on the inner surface of the inner tube 2, so that the locking rod 305 can be retracted into the sealing plug 301, and then the residual water in the inner tube 2 can be released, thereby realizing subsequent deep maintenance and cleaning.

[0020] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed in the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A vacuum tube for a solar water heater, comprising an outer tube (1), characterized in that: The inner end of the outer tube (1) is fixedly mounted with an inner tube (2), a bellows (3) is passed through the inner tube (2), a center tube (4) is passed through the inner tube (3), and a temperature control transmission device is arranged inside the center tube (4), a center shaft (204) is detachably and rotatably mounted on the lower end of the center tube (4), a stabilizing sleeve (201) is sleeved on the inner end of the inner tube (2), the stabilizing sleeve (201) is located below the center tube (4), and the center shaft (204) is passed through the inner side of the stabilizing sleeve (201), and a sealing plug (301) is detachably mounted on the bottom end of the inner tube (2); The temperature control transmission device comprises a stabilizing disk (101), a passive rod (103) being fixedly mounted on the bottom end of the stabilizing disk (101), a double helical metal sheet (401) which can change shape according to temperature changes being passed through the inner end of the central tube (4), and a connecting rod (31) being fixedly mounted on the outer surface of the bellows (3).

2. The vacuum tube of a solar water heater according to claim 1, characterized in that: The connecting rod (31) is used to provide stable support for the corrugated tube (3); a stabilizing ring (402) is fixedly mounted on the bottom end of the central tube (4); an outer surface of the stabilizing ring (402) is fixedly connected to the bottom end of the connecting rod (31); and the central axis (204) and the stabilizing ring (402) are on the same axis.

3. The vacuum tube of a solar water heater according to claim 2, characterized in that: A connecting ring (404) is fixedly mounted on the upper end of the double-helix metal sheet (401), and the lower end of the passive rod (103) is inserted through the inner end of the connecting ring (404).

4. The vacuum tube of a solar water heater according to claim 3, characterized in that: A limiting plate (109) is arranged above the stabilizing plate (101), a plurality of stabilizing cylinders (106) are fixedly mounted on the lower end of the limiting plate (109), and the stabilizing cylinders (106) are all penetrated through the inner end of the stabilizing plate (101), and abutment balls (107) are penetrated through the outer surfaces of the stabilizing cylinders (106), and the abutment balls (107) are located below the stabilizing plate (101).

5. The vacuum tube of a solar water heater according to claim 1, characterized in that: A scraper (203) is rotatably mounted on the upper end of the stabilizing sleeve (201), and the outer surface of the scraper (203) is in contact with the inner wall of the inner tube (2); the scraper (203) is fixedly mounted on the outer surface of the central shaft (204), and the scraper (203), the stabilizing sleeve (201) and the central shaft (204) are on the same axis, and the central shaft (204) is rotatably connected to the stabilizing sleeve (201).

6. The vacuum tube of a solar water heater according to claim 5, characterized in that: The inner wall of the stabilizing sleeve (201) is provided with an annular spring piece (205), the outer surface of the stabilizing sleeve (201) is provided with a plurality of holes, a wall-breaking ball (202) is arranged in the holes, and an arc groove is fixedly installed on the end surface of the annular spring piece (205) close to the wall-breaking ball (202), and the outer surface of the wall-breaking ball (202) is in contact with the outer surface of the arc groove.

7. The vacuum tube of a solar water heater according to claim 6, characterized in that: A trapezoidal block (304) is provided at the inner end of the sealing plug (301), and the trapezoidal block (304) gradually widens from top to bottom. A plurality of locking rods (305) are provided at the outer surface of the sealing plug (301).

8. The vacuum tube of a solar water heater according to claim 7, characterized in that: A screw cap (302) is rotatably mounted on the bottom end of the trapezoidal block (304), and the sealing plug (301) is threadedly sleeved on the outer surface of the screw cap (302).

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