Anti-freezing device and water heater comprising same

Abstract

The application discloses an anti-freezing device and a water heater comprising the same. The anti-freezing device comprises a cavity for water flow, a valve core comprising a first end in the cavity and a second end outside the cavity, a limiting sleeve sleeved on the periphery of the valve core and limiting the movement of the valve core towards the first end, a fixing groove being formed on the limiting sleeve, a locking member provided on the second end of the valve core, the locking member being in a sheet structure and being integrally formed, a fixed part being formed by bending and being fixed relative to the anti-freezing device, a contact part being sleeved on the second end of the valve core, and a limiting part passing through the fixing groove and limiting the movement of the limiting sleeve towards the first end, a guide surface being provided on the side of the second end of the valve core in contact with the contact part, the guide surface being inclined from the second end to the first end so that the thickness of the valve core gradually increases, and an end of the contact part away from the limiting part being arranged on the guide surface, and a reset mechanism driving the valve core and the limiting sleeve to move towards the first end.

Description

Technical Field

[0001] This invention relates to the field of water heater technology, and more specifically to an antifreeze device and a water heater containing the same. Background Technology

[0002] A water heater is a device that uses various physical principles to raise the temperature of cold water to produce hot water within a certain time. Taking a gas water heater as an example, during use, the inlet pipe of the gas water heater delivers cold water to the heat exchanger, where the gas combustion heats the water, and then the water is delivered to the user through the outlet pipe.

[0003] Gas water heaters are generally connected to the outdoor environment through a flue pipe. In cold winters, when the outdoor temperature is low, cold air can easily enter the water heater through the flue pipe, causing the water in the internal pipes to freeze. As the water expands, it can easily cause the pipes to crack. When the temperature rises, the ice in the pipes melts. If the user does not notice this in time and close the inlet valve, the entire unit will leak, causing water damage to the base plate, electrical leakage, and other property damage and safety issues.

[0004] In response to the above situation, gas water heaters installed in cold northern environments are generally equipped with electric heating anti-freeze devices to provide a certain degree of freeze protection. However, the electric heating anti-freeze device can only start working properly when the water heater is powered on. If there is a power outage, such as when the user unplugs the power cord or there is a power failure in the house, the electric heating device may still fail to start, causing the water heater pipes to freeze and crack. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defect that the installation of electric heating devices in the prior art cannot completely solve the problem of water leakage caused by the freezing and cracking of pipes inside the water heater at low temperatures, and to provide an antifreeze device and a water heater containing the same.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution:

[0007] An antifreeze device, characterized in that the antifreeze device comprises:

[0008] A cavity for the passage of water;

[0009] A valve core, the valve core comprising a first end located within the cavity and a second end located outside the cavity;

[0010] A limiting sleeve is provided around the valve core and restricts the valve core from moving toward the first end. A fixing groove is provided on the limiting sleeve.

[0011] A locking element is provided at the second end of the valve core. The locking element is a sheet-like structure and integrally formed. It is formed by bending to form a fixing part that is fixed relative to the antifreeze device, a contact part sleeved on the second end of the valve core, and a limiting part that passes through the fixing groove and restricts the movement of the limiting sleeve toward the first end.

[0012] The second end of the valve core is provided with a guide surface on the side that contacts the contact portion. The guide surface is inclined from the second end to the first end, so that the thickness of the valve core gradually increases. The end of the contact portion away from the limiting portion is provided on the guide surface.

[0013] A reset mechanism drives the valve core and the limiting sleeve to move toward the first end.

[0014] In this design, under normal operating conditions, the valve core is limited by a limiting sleeve, which is further limited by a locking element. This prevents both the valve core and the limiting sleeve from moving towards the first end of the valve core, thus limiting the valve core and preventing it from blocking water flow. Water then flows normally through the cavity. When the outdoor temperature is low, cold air enters the water heater through the exhaust pipe, causing the water inside the cavity to freeze. As the water freezes and its volume increases, it exerts an external force on the first end of the valve core, causing it to move towards its second end. As the valve core moves, the contact portion fitted onto the second end of the valve core gradually slides under the guidance of the guide surface. During this process, the contact portion continuously slides along the guide surface, pulling the limiting portion until it finally disengages from the fixing groove of the limiting sleeve. The locking element no longer restricts the limiting sleeve from moving towards the first end. When the outdoor temperature rises or the ice melts due to other reasons, both the valve core and the limiting sleeve move towards their first ends under the action of the reset mechanism, causing the valve core to seal the cavity. If the pipes inside the water heater have already frozen and cracked, the antifreeze device can prevent water from flowing into the water heater, thereby avoiding water leakage from the entire unit, which could cause property damage and safety issues such as water damage to the base plate and electrical leakage.

[0015] Preferably, the antifreeze device further includes an extension sleeve, which is connected to the cavity and extends outward in the radial direction of the cavity, and the first end of the valve core is disposed in the extension sleeve and is movable in the axial direction of the extension sleeve.

[0016] The limiting sleeve is connected to the extension sleeve and is fixed relative to the cavity through the extension sleeve.

[0017] In this solution, by connecting an extension sleeve to the side wall of the cavity, the valve core is confined within the extension sleeve, allowing the valve core to move along a specific trajectory, and further preventing the valve core from detaching from the cavity during movement.

[0018] Preferably, the cavity is provided with a first partition and a second partition at intervals along its radial direction, and the first partition and the second partition form a first flow port and a second flow port respectively between the first partition and the side wall of the cavity;

[0019] The cavity has a third partition plate arranged along its axial direction inside, and a third flow port is opened on the third partition plate. The third partition plate is connected to the first partition plate and the second partition plate respectively. The water flows through the first flow port, the third flow port and the second flow port in sequence in the cavity.

[0020] In this design, the water inside the cavity flows through the first or second flow port and then out through the third flow port, which is opened radially towards the cavity. At this time, the valve core only needs to be in contact with the third flow port to close the cavity. Compared with a completely closed cavity, this design is simpler and more reliable, and it will not hinder the flow of water inside the cavity during normal use of the water heater.

[0021] Preferably, the valve core moves toward the first end and can abut against the third partition plate and close the third flow port.

[0022] In this design, by setting a partition, the opening inside the cavity is aligned with the valve core, making it convenient for the valve core to directly control the opening or closing of the cavity through lateral movement.

[0023] Preferably, the reset mechanism includes a first elastic element and a second elastic element, the first elastic element abutting against the wall surfaces of the valve core and the extension sleeve respectively, and the second elastic element abutting against the wall surfaces of the limiting sleeve and the extension sleeve respectively.

[0024] In this design, by setting up an elastic element, both the valve core and the limiting sleeve are in a compressed state when the cavity is open, so that both have the potential energy to move towards the first end, which facilitates spontaneous movement towards the first end and closing the cavity after the limiting is released.

[0025] Preferably, the fixing part is fixed to the extension sleeve.

[0026] In this design, the fixing part is fixed to the extension sleeve, which is easy to install and does not affect the movement of the valve core and the limit sleeve.

[0027] Preferably, the extension sleeve also includes a limiting groove, and the limiting part passes through the fixing groove and is engaged in the limiting groove.

[0028] In this solution, the limiting part limits the limiting sleeve by passing through the fixing groove opened on the limiting sleeve and locking into the limiting groove on the extension sleeve. When the limiting part is locked into the limiting groove, the locking part, the extension sleeve, the limiting sleeve and the valve core are all fixed, thereby maintaining the flow of the cavity.

[0029] Preferably, the connection between the fixing part and the contact part is bent into a protrusion in the direction of the limiting sleeve to form the limiting part.

[0030] In this design, the limiting part is located at the connection between the contact part and the fixing part, which is itself a bending position. Furthermore, the limiting part is formed into a protrusion shape through multiple bends, which makes its structure more stable and prevents it from deforming as the contact part moves, thus losing its limiting effect.

[0031] Preferably, a sealing ring is provided between the valve core and the limiting sleeve.

[0032] In this solution, the sealing effect between the limit sleeve and the valve core can be improved by setting a sealing ring.

[0033] A water heater, characterized in that the water heater comprises:

[0034] Water heater body;

[0035] As described above, the outlet of the antifreeze device is connected to the inlet of the water heater body.

[0036] In this solution, the aforementioned antifreeze device is applied to the water heater body, effectively solving the problem that installing an electric heating device in the water heater cannot completely prevent the pipes inside the water heater from freezing and cracking at low temperatures, thus causing water leakage.

[0037] The positive and progressive effects of this invention are as follows: Under normal use of the water heater, the valve core is limited by the limiting sleeve, and the limiting sleeve is further limited by the locking element, preventing both the valve core and the limiting sleeve from moving towards the first end of the valve core. This limits the valve core's ability to block water flow, allowing water to flow normally through the cavity. When the outdoor temperature is low, cold air enters the water heater through the exhaust pipe, causing the water inside the cavity to freeze continuously. As the water freezes and its volume increases, it applies external force to the first end of the valve core, causing it to move towards its second end. This movement of the valve core presses against the protrusion of the locking element. During this process, the protrusion of the locking component extends towards the second end and gradually becomes flat. The hooks at both ends, under the extending action, gradually change from being outwardly raised to inwardly contracting and also gradually becoming flat. Ultimately, the hooks disengage from the limiting groove of the limiting sleeve, and the locking component no longer restricts the limiting sleeve from moving towards the first end. When the outdoor temperature rises or ice melts due to other reasons, both the valve core and the limiting sleeve move towards their first ends under the action of the reset mechanism, causing the valve core to seal the cavity. If the pipes inside the water heater have already frozen and cracked, the antifreeze device can prevent water from entering the water heater, thus avoiding leaks that could cause water damage to the base plate, electrical leaks, and other property and safety issues. Attached Figure Description

[0038] Figure 1This is a schematic diagram of the antifreeze device according to an embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of the antifreeze device in normal condition according to an embodiment of the present invention.

[0040] Figure 3 This is a schematic diagram of the antifreeze device in an icing state according to an embodiment of the present invention.

[0041] Figure 4 This is a schematic diagram of the antifreeze device in a closed state according to an embodiment of the present invention.

[0042] Figure 5 This is a schematic diagram of the antifreeze device in the reset state according to an embodiment of the present invention.

[0043] Figure 6 This is a schematic diagram of the locking component of the antifreeze device according to an embodiment of the present invention.

[0044] Figure 7 This is a schematic diagram of the locking component and the limiting sleeve of the antifreeze device according to an embodiment of the present invention.

[0045] Explanation of reference numerals in the attached figures:

[0046] Antifreeze device 1

[0047] Cavity 100

[0048] First partition 110

[0049] Second partition 120

[0050] Third partition 130

[0051] Third outlet 131

[0052] Valve core 200

[0053] First end 210

[0054] Second end 220

[0055] Guide surface 230

[0056] Seal 240

[0057] Limiting sleeve 300

[0058] Fixed slot 310

[0059] Reset bump 320

[0060] Extension sleeve 400

[0061] Limiting groove 410

[0062] Locking component 500

[0063] Fixing part 510

[0064] Limiting part 520

[0065] Contact part 530

[0066] First elastic element 620

[0067] Second elastic element 610 Detailed Implementation

[0068] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0069] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "circumferential," and "radial," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0070] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0071] This embodiment provides an antifreeze device 1, which includes a cavity 100 for water flow; a valve core 200, which includes a first end 210 located inside the cavity 100 and a second end 220 located outside the cavity 100; a limiting sleeve 300, which is sleeved around the valve core 200 and restricts the movement of the valve core 200 toward the first end 210, and has a fixing groove 310 on it; and a locking member 500, which is located at the second end 220 of the valve core 200. The locking member 500 is a sheet-like structure and integrally formed, and is bent to form a shape relative to the antifreeze device 1. The valve core 200 has a fixed fixing part 510, a contact part 530 sleeved on the second end 220 of the valve core 200, and a limiting part 520 that passes through the fixing groove 310 and restricts the movement of the limiting sleeve 300 toward the first end 210. A guide surface 230 is provided on the side of the second end 220 of the valve core 200 that contacts the contact part 530. The guide surface 230 is inclined from the second end 220 toward the first end 210, so that the thickness of the valve core 200 gradually increases. The end of the contact part 530 away from the limiting part 520 is provided on the guide surface 230. A reset mechanism drives the valve core 200 and the limiting sleeve 300 to move toward the first end 210.

[0072] In this embodiment, under normal use of the water heater, the valve core 200 is limited by the limiting sleeve 300. The limiting sleeve 300 is limited by the locking member 500, so that neither the valve core 200 nor the limiting sleeve 300 can move toward the first end 210 of the valve core 200. This makes the valve core 200 limited and unable to block the water flow. At this time, the water flows normally through the cavity 100. When the outdoor temperature is low, cold air enters the interior of the water heater through the exhaust pipe, causing the water inside the cavity 100 to freeze continuously. As the water increases in volume after freezing, it applies an external force to the first end 210 of the valve core 200, causing the valve core 200 to move towards its second end 220. When the valve core 200 moves, the contact part 530 sleeved on the second end 220 of the valve core 200 gradually slides under the action of the guide surface 230. During this process, the contact part 530 continuously slides along the guide surface 230 and pulls the limiting part 520, eventually causing the limiting part 520 to disengage from the fixing groove 310 of the limiting sleeve 300. The locking member 500 no longer restricts the limiting sleeve 300 from moving towards the first end 210. When the outdoor temperature rises or the ice melts due to other reasons, the valve core 200 and the limiting sleeve 300 both move towards their first end 210 under the action of the reset mechanism, and drive the valve core 200 to seal the cavity 100. If the pipes inside the water heater have already frozen and cracked, the antifreeze device 1 can prevent water from flowing into the water heater, thereby avoiding water leakage from the whole unit, which could cause property damage and safety issues such as water damage to the base plate and electrical leakage.

[0073] like Figure 6 , 7As shown, both the limiting sleeve 300 and the valve core 200 in this embodiment are cylindrical. The locking member 500 is formed by bending a sheet-like part through stamping or other methods. In this embodiment, the fixing part 510 of the locking member 500 is fixed to the baffle of the limiting sleeve 300, and one end of it is bent and extends to the contact part 530. The contact part 530 is an annular part with a hollow interior, and the second end 220 of the valve core 200 passes through the contact part 530. The limiting part 520 of the locking member 500 is formed between the fixing part 510 and the contact part 530. The connection positions of the locking member 500 and the fixing part 510 and the contact part 530 are all bent outward once to form a protruding structure, which facilitates its cooperation with the limiting groove 410 and the fixing groove 310. A guide surface 230 is provided on the side of the second end 220 of the valve core 200 away from the limiting part 520. This guide surface 230 is inclined, making the second end 220 of the valve core 200 thinner and thicker closer to the first end 210. In the initial state, such as Figure 2 As shown, the contact portion 530 is located at the end of the guide surface 230 closest to the second end 220, at which point the valve core 200 is at its thinnest, and the end of the contact portion 530 furthest from the limiting portion 520 abuts against the guide surface 230. In winter, when temperatures are low and the surface is frozen, such as... Figure 3 As shown, when the valve core 200 moves to the right, it becomes increasingly thicker. Under the action of the guide surface 230, the contact portion 530 is gradually squeezed by the valve core 200, moving away from the limiting portion 520 and pulling the limiting portion 520 to disengage completely from the fixing groove 310. This releases the limiting sleeve 300. When the ice melts, as... Figure 4 As shown, under the action of the recovery mechanism, both the limit sleeve 300 and the valve core 200 move toward the first end 210 and close the water chamber.

[0074] In addition, the antifreeze device 1 also has a reset function; when a reset is required, such as... Figure 4 As shown, the limiting sleeve 300 is pushed to the right. During the movement of the resetting protrusion 320 of the limiting sleeve 300 to the second end 220, it touches the limiting block and is released from the inclined surface on the limiting block. The inclined surface then presses the limiting block into the fixing groove 310 until the resetting is completed.

[0075] like Figure 1 As shown, the antifreeze device 1 also includes an extension sleeve 400, which is connected to the cavity 100 and extends outward in the radial direction of the cavity 100. The first end 210 of the valve core 200 is disposed in the extension sleeve 400 and is movable in the axial direction of the extension sleeve 400.

[0076] The limiting sleeve 300 is connected to the extension sleeve 400 and is fixed relative to the cavity 100 through the extension sleeve 400.

[0077] In this embodiment, by connecting an extension sleeve 400 to the side wall of the cavity 100, the valve core 200 is limited within the extension sleeve 400, so that the movement of the valve core 200 can follow a specific trajectory, and can further prevent the valve core 200 from detaching from the cavity 100 during the movement.

[0078] like Figure 2 As shown, the cavity 100 has a first partition 110 and a second partition 120 spaced apart along its radial direction. The first partition 110 and the second partition 120 form a first flow port and a second flow port with the side wall of the cavity 100, respectively.

[0079] A third partition 130 is provided inside the cavity 100 along its axial direction. A third flow port 131 is provided on the third partition 130. The third partition 130 is connected to the first partition 110 and the second partition 120 respectively. Water flows through the first flow port, the third flow port 131 and the second flow port in sequence in the cavity 100.

[0080] In this embodiment, with this arrangement, the water inside the cavity 100 flows out through the first or second flow port and then out through the third flow port opened in the radial direction of the cavity 100. At this time, the valve core 200 only needs to abut against the third flow port to close the cavity 100. Compared with completely closing the cavity 100, this is simpler and more reliable, and it will not hinder the flow of water inside the cavity 100 during normal use of the water heater.

[0081] like Figure 4 As shown, the valve core 200 moves toward the first end 210 and can abut against the third partition 130 and close the third flow port.

[0082] In this embodiment, by setting a partition, the opening in the cavity 100 is in the same direction as the valve core 200, which makes it convenient for the valve core 200 to directly control the opening or closing of the cavity 100 by lateral movement.

[0083] like Figure 2 As shown, the reset mechanism includes a first elastic element 620 and a second elastic element 610. The first elastic element 620 abuts against the walls of the valve core 200 and the extension sleeve 400, respectively, and the second elastic element 610 abuts against the walls of the limiting sleeve 300 and the extension sleeve 400, respectively.

[0084] In this embodiment, by setting an elastic element, both the valve core 200 and the limiting sleeve 300 are in a compressed state when the cavity 100 is open, so that the two maintain the potential energy to move towards the first end 210, which facilitates spontaneous movement towards the first end 210 and closing the cavity 100 after the limiting is released.

[0085] like Figures 2 to 4 As shown, the fixing part 510 is fixed to the extension sleeve 400.

[0086] In this embodiment, the fixing part 510 is fixed to the extension sleeve 400, which is easy to set and does not affect the movement of the valve core 200 and the limiting sleeve 300.

[0087] like Figures 2 to 7 As shown, the extension sleeve 400 also includes a limiting groove 410, and the limiting part 520 passes through the fixing groove 310 and is locked in the limiting groove 410.

[0088] In this embodiment, the limiting part 520 limits the limiting sleeve 300 by passing through the fixing groove 310 opened on the limiting sleeve 300 and locking into the limiting groove 410 on the extension sleeve 400. When the limiting part 520 is locked into the limiting groove 410, the locking member 500, the extension sleeve 400, the limiting sleeve 300 and the valve core 200 are all fixed, thereby maintaining the flow of the cavity 100.

[0089] like Figures 2 to 7 As shown, the connection between the fixing part 510 and the contact part 530 is bent in the direction of the limiting sleeve 300 to form a protruding limiting part 520.

[0090] In this embodiment, the limiting part 520 is located at the connection position between the contact part 530 and the fixing part 510. This position is itself a bending position. Furthermore, the limiting part 520 is formed into a protrusion shape by bending multiple times, which makes its structure more stable and prevents it from deforming and losing its limiting effect as the contact part 530 moves.

[0091] like Figure 2 As shown, a sealing ring is provided between the valve core 200 and the limit sleeve 300.

[0092] In this embodiment, the sealing effect between the limit sleeve 300 and the valve core 200 can be improved by setting a sealing ring.

[0093] A water heater characterized in that it comprises:

[0094] Water heater body;

[0095] The antifreeze device 1 described above has its outlet connected to the inlet of the water heater body.

[0096] In this embodiment, the above-mentioned antifreeze device 1 is applied to the water heater body, which effectively solves the defect that the installation of electric heating device in water heater cannot completely solve the problem of water leakage caused by the freezing and cracking of pipes inside the water heater at low temperature.

[0097] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A freeze protection device, characterized in that, The anti-freezing device comprises: a cavity for water flow; a valve core comprising a first end in the cavity and a second end outside the cavity; a limiting sleeve surrounding the valve core and limiting the movement of the valve core towards the first end, the limiting sleeve being provided with a fixing groove; a locking member provided on the second end of the valve core, the locking member being in a sheet structure and integrally formed, the locking member comprising a fixing part for fixing the anti-freezing device, a contact part surrounding the second end of the valve core, and a limiting part passing through the fixing groove and limiting the movement of the limiting sleeve towards the first end; a guide surface provided on the side of the second end of the valve core in contact with the contact part, the guide surface being inclined from the second end to the first end so that the thickness of the valve core gradually increases, and the end of the contact part away from the limiting part being arranged on the guide surface; a reset mechanism driving the valve core and the limiting sleeve to move towards the first end.

2. The freeze protection apparatus of claim 1, wherein The anti-freezing device further comprises an extension sleeve connected to the cavity and extending outwardly along the radial direction of the cavity, the first end of the valve core being arranged in the extension sleeve and being movable along the axial direction of the extension sleeve; the limiting sleeve is connected to the extension sleeve and is fixed relative to the cavity through the extension sleeve.

3. The freeze protection apparatus of claim 1, wherein The cavity is provided with a first partition plate and a second partition plate spaced apart along the radial direction of the cavity, the first partition plate and the second partition plate forming a first flow passage and a second flow passage, respectively, between the first partition plate and the second partition plate and the side wall of the cavity; the cavity is provided with a third partition plate along the axial direction of the cavity, the third partition plate being provided with a third flow passage, the third partition plate being connected to the first partition plate and the second partition plate, respectively, and water flowing in the cavity sequentially flows through the first flow passage, the third flow passage, and the second flow passage.

4. The freeze protection apparatus of claim 3, wherein The valve core moves towards the first end and can be arranged on the third partition plate and close the third flow passage.

5. The freeze protection apparatus of claim 2, wherein The reset mechanism comprises a first elastic member and a second elastic member, the first elastic member being arranged on the wall surface of the valve core and the extension sleeve, respectively, and the second elastic member being arranged on the wall surface of the limiting sleeve and the extension sleeve, respectively.

6. The freeze protection apparatus of claim 2, wherein The fixing part is fixed on the extension sleeve.

7. The freeze protection apparatus of claim 2, wherein The extension sleeve is further provided with a limiting groove, the limiting part being clamped in the limiting groove after passing through the fixing groove.

8. The freeze protection apparatus of claim 2, wherein, The connection between the fixing part and the contact part is bent towards the limiting sleeve to form the limiting part in a convex shape.

9. The freeze protection apparatus of claim 1, wherein, A sealing ring is arranged between the valve core and the limiting sleeve.

10. A water heater, characterized by The water heater comprises: a water heater body; the anti-freezing device according to any one of claims 1 to 9, the water outlet of the anti-freezing device being connected to the water inlet end of the water heater body.

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