Phase change heat exchange water tank and welding method

Abstract

The invention discloses a phase change heat exchange water tank and a welding method, the phase change heat exchange water tank comprises a heat exchanger assembly and a tank body used for packaging the heat exchanger assembly therein, the heat exchanger assembly comprises a copper pipe structure used for heating water in the water tank and capable of monitoring water temperature, and the tank body comprises a stainless steel plate arranged at the bottom; the stainless steel plate is provided with a through hole for the copper pipe structure to penetrate out to be connected with external equipment, and a stainless steel lantern ring used for preventing the stainless steel plate from deforming during welding is arranged at the joint of the copper pipe structure and the through hole. According to the hot water tank, the stainless steel lantern ring is welded to one end of the copper pipe structure, and then the stainless steel lantern ring is welded to the stainless steel plate, so that direct welding of the copper pipe structure and the stainless steel plate can be avoided, thermal deformation of the stainless steel plate is avoided, and phase-change materials are easily leaked; and on the other hand, as the stainless steel lantern ring and the stainless steel plate are made of the same material, uniform fusion and good welding quality can be obtained more easily in the welding process, and the stainless steel plate is not prone to deformation in the welding process.

Description

[Technical field] The invention relates to the technical field of hot water devices, and in particular to a phase-change hot water tank and a welding method. [Background technology] Phase change hot water tank is a device that uses phase change material (PCM) to store and release heat energy. It achieves heat storage and transfer by absorbing or releasing a large amount of latent heat during the phase change process. Phase change hot water tanks are usually equipped with heating copper tubes and temperature detection copper tubes. These copper tubes need to pass through the tank to connect with external equipment. The exit point must be sealed to prevent leakage of phase change materials.

[0003] In order to seal the exit point of the existing phase change hot water tank to prevent leakage of the phase change material, the exposed copper tube is usually passed through the through hole of the bottom plate of the stainless steel box body, and then the copper tube is brazed together with the stainless steel plate at the bottom of the box body by flame brazing with a silver-based brazing material for sealing. However, since the temperature of silver-based flame brazing is generally above 700°C, the copper tube and the stainless steel plate are prone to thermal deformation during the high-temperature brazing process, causing the box body to deform, thereby causing the sealing of the box to deteriorate; when the deformation is serious, it may even be impossible to weld and become scrapped. [Summary of the invention] In order to solve the technical problem that copper tubes and stainless steel plates are easily thermally deformed during high-temperature brazing, resulting in poor sealing performance of the tank or even scrapping, the present invention proposes a phase change hot water tank and a welding method.

[0005] To achieve the above-mentioned purpose, the present invention proposes a phase change hot water tank, comprising a heat exchanger assembly and a box body for encapsulating the heat exchanger assembly, wherein the heat exchanger assembly comprises a copper tube structure for heating water in the hot water tank and monitoring the water temperature, and the box body comprises a stainless steel plate arranged at the bottom, the stainless steel plate is provided with a through hole for the copper tube structure to pass through and connect to an external device, and a stainless steel collar is provided at the connection between the copper tube structure and the through hole for preventing deformation of the stainless steel plate during welding.

[0006] In the phase-change hot water tank as described above, the copper tube structure comprises an exposed copper tube and an internal copper tube, and one end of the exposed copper tube passing through the through hole is welded with the stainless steel sleeve.

[0007] In the phase-change hot water tank as described above, the exposed copper tubes include a plurality of heating copper tubes for heating water in the hot water tank and a plurality of temperature-detecting copper tubes for monitoring the water temperature in the hot water tank.

[0008] In the phase-change hot water tank as described above, the built-in copper tubes include a plurality of heat-exchange copper tubes for conducting heat in the hot water tank, and the heat-exchange copper tubes are U-shaped copper tubes.

[0009] In the phase-change hot water tank as described above, the heat exchanger assembly further comprises heat exchange fins for improving heat transfer efficiency, and the heat exchange fins are expanded into one piece with the copper tube structure.

[0010] In the phase-change hot water tank as described above, the heat exchange fins are punched with a plurality of connection holes for the copper tube structure to pass through for expansion connection.

[0011] In the phase change hot water tank as described above, the tank body further comprises a fixing member for improving the connection tightness of the stainless steel plate, and the fixing member is a stainless steel hoop.

[0012] In the phase-change hot water tank as described above, the through holes and the connecting holes are both flanged holes.

[0013] In addition, to achieve the above object, the present invention also proposes a welding method for a phase change hot water tank, which is used to manufacture the phase change hot water tank as described above, and the welding method comprises: Solder the stainless steel collar to the exposed copper tube by brazing; The exposed copper tube and the internal copper tube are expanded into one with the heat exchange fins through the tube expansion process; The stainless steel sleeve ring is welded to the stainless steel plate by argon arc welding.

[0014] The welding method of the phase change hot water tank as described above, wherein the step of expanding the exposed copper tube and the internal copper tube into one piece with the heat exchange fins through the tube expansion process, further comprises the following steps: Making pre-expanded tube workpieces; The pre-expanded tube workpiece is expanded.

[0015] Compared with the prior art, the phase change hot water tank and welding method proposed in the present invention have the following beneficial effects: 1. The phase change hot water tank proposed by the present invention welds a stainless steel collar at one end of the copper tube structure, and then welds the stainless steel collar to the stainless steel plate. On the one hand, direct welding of the copper tube structure and the stainless steel plate can be avoided, which would cause thermal deformation of the stainless steel plate and thus easily leak the phase change material. On the other hand, since the stainless steel collar and the stainless steel plate are made of the same material, uniform fusion and good welding quality can be more easily obtained during the welding process, so that the stainless steel plate is not easily deformed during the welding process.

[0016] 2. The stainless steel sleeve ring and stainless steel proposed in the present invention are welded by argon arc welding. Since the heat of argon arc welding is concentrated and the heat-affected zone is narrow, the stress, deformation and crack tendency of the weldment after welding are small, which makes the stainless steel plate at the bottom of the hot water tank less likely to deform during the welding process and has better sealing.

[0017] 3. The stainless steel sleeve ring and the stainless steel plate proposed in the present invention are made of the same material, so that uniform fusion and good welding quality can be more easily obtained during the welding process, thereby preventing the stainless steel plate from being deformed during the welding process.

Brief Description of the Drawings

[0019] Figure 1 A schematic diagram of the structure of a phase change hot water tank proposed in an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the decomposition of Figure 3 A schematic diagram of the structure of a heat exchanger assembly in a phase-change hot water tank proposed in an embodiment of the present invention; Figure 4 A schematic diagram of the structure of a heat exchange fin in a phase change hot water tank proposed in an embodiment of the present invention; Figure 5 This is an exploded schematic diagram of a copper tube and a stainless steel sleeve ring in a phase-change hot water tank proposed in an embodiment of the present invention; Figure 6 A specific flow chart of a welding method for a phase change hot water tank proposed in an embodiment of the present invention; Figure 7 for Figure 6 The specific flow chart of the steps of expanding the exposed copper tube and the internal copper tube into one with the heat exchange fin through the tube expansion process; Figure 8 A specific flow chart of another welding method for a phase change hot water tank proposed in an embodiment of the present invention [Specific implementation method] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] Please refer to Figures 1 to 5As shown, the embodiment of the present invention proposes a phase change hot water tank, including a heat exchanger assembly 10 and a box 20 for encapsulating the heat exchanger assembly 10, the heat exchanger assembly 10 includes a copper tube structure 11 for heating water in the hot water tank and monitoring the water temperature, the box 20 includes a stainless steel plate 21 arranged at the bottom, the stainless steel plate 21 is provided with a through hole 211 for the copper tube structure 11 to pass through and connect with external equipment, and a stainless steel collar 30 is provided at the connection between the copper tube structure 11 and the through hole 211 to prevent the stainless steel plate 21 from deforming during welding. The hot water tank is welded with a stainless steel collar 30 at one end of the copper tube structure 11, and then welded with the stainless steel plate 21 through the stainless steel collar 30. On the one hand, it can avoid direct welding of the copper tube structure 11 with the stainless steel plate 21, causing thermal deformation of the stainless steel plate 21, thereby easily leaking the phase change material; on the other hand, since the stainless steel collar 30 and the stainless steel plate 21 are made of the same material, it is easier to obtain uniform fusion and good welding quality during the welding process, so that the stainless steel plate 21 is not easily deformed during the welding process.

[0021] Further, as a preferred implementation of the present solution but not a limitation, the copper tube structure 11 includes an exposed copper tube 111 and a built-in copper tube 112, and one end of the exposed copper tube 111 passing through the through hole 211 is welded with the stainless steel collar 30; The through hole 211 is a flanging hole.

[0022] In this embodiment, the through hole is designed as a flanged hole, which increases the material thickness around the through hole, can withstand greater external pressure and internal stress, improves the sealing performance between the exposed copper tube and the stainless steel plate, and reduces the risk of leakage; at the same time, it also provides a larger welding area, making the connection between the stainless steel ring and the through hole tighter.

[0023] Furthermore, as a preferred implementation of the present solution but not a limitation, the exposed copper tube 111 includes a plurality of heating copper tubes 1111 for heating water in the hot water tank and a plurality of temperature detection copper tubes 1112 for monitoring the water temperature in the hot water tank.

[0024] One end of the heating copper tube 1111 passes through the through hole 211 to provide a space for inserting the electric heating tube, and one end of the temperature detection copper tube 1112 passes through the through hole 211 to be connected to the temperature sensor so as to monitor the water temperature in the hot water tank; In addition, one end of the heating copper tube 1111 and the temperature detection copper tube 1112 passing through the through hole 211 is welded with the stainless steel ring 30 .

[0025] In this embodiment, the design of multiple heating copper tubes can distribute heat more evenly, improve the heating efficiency of the phase change material in the heat exchange water tank, and ensure that the temperature in the entire heat exchange water tank is more uniform; multiple temperature detection copper tubes can monitor the temperature of the phase change material at different positions, provide more accurate temperature data, and help the control system adjust the heating power according to actual needs, thereby optimizing the thermal energy utilization efficiency; In addition, the heating copper tubes and temperature detection copper tubes that need to pass through the through holes to connect to external equipment are welded with stainless steel rings, which enhances the mechanical strength of the connection between the copper tube and the stainless steel plate, strengthens the sealing, and reduces the risk of phase change material leakage from the connection.

[0026] Furthermore, as a preferred implementation of the present solution but not a limitation, the built-in copper tube 112 includes a plurality of heat exchange copper tubes 1121 for conducting heat in the hot water tank, and the heat exchange copper tubes 1121 are U-shaped copper tubes.

[0027] In this embodiment, the heat exchange copper tube is designed as a U-shaped copper tube, which increases the total length of the heat exchange copper tube, thereby increasing the contact area with water or phase change material, and thus can transfer heat more efficiently; at the same time, it can also guide the fluid (such as water or heat transfer medium) to flow along a predetermined path, forming natural convection, further improving the heat exchange efficiency.

[0028] Furthermore, as a preferred implementation of the present solution but not a limitation, the heat exchanger assembly 10 also includes a heat exchange fin 12 for improving heat transfer efficiency, the heat exchange fin 12 is expanded into one with the copper tube structure 11, and the heat exchange fin 12 is stamped with a plurality of connection holes 121 for the copper tube structure 11 to pass through for expansion connection.

[0029] The tube expansion is a metal processing technology, and its specific principle is: by using a tube expander or a tube expansion die to extend into the pipe, the diameter of the pipe is expanded by mechanical pressure or thermal force, so as to be tightly connected with the tube sheet or other components; In addition, the connection holes 121 are flanged holes, and the number of the connection holes 121 corresponds to the sum of the numbers of the heat exchange copper tubes 111 , the heating copper tubes 112 , and the temperature detection copper tubes 113 .

[0030] In this embodiment, the heat exchange fins greatly increase the heat exchange area and promote the transfer of heat from the copper tube to the surrounding medium (such as water or phase change material), thereby improving the overall heat exchange efficiency; in addition, the heat exchange fins are tightly connected to the copper tube structure through the tube expansion process, ensuring the firmness and sealing between the two. This connection method is more reliable than traditional welding or bonding, and reduces the risk of loosening due to temperature changes or mechanical stress.

[0031] Furthermore, as a preferred implementation of the present solution but not a limitation, the box body 20 further includes a fixing member 22 for improving the connection tightness of the stainless steel plate 21, and the fixing member 22 is a stainless steel hoop.

[0032] In this embodiment, the stainless steel hoop can ensure a close fit between the stainless steel plate and other parts of the tank (such as the side wall), reducing the tiny gap caused by thermal expansion and contraction or other factors, thereby improving the sealing of the entire hot water tank and preventing leakage of the phase change material.

[0033] Please refer to Figure 6 to Figure 7 As shown, an embodiment of the present invention further provides a welding method for a phase change hot water tank, the welding method is used to manufacture the phase change hot water tank as described above, the welding method comprises: The stainless steel sleeve ring 30 and the exposed copper tube 111 are welded by brazing.

[0034] Specifically, the exposed copper tube 111 includes a heating copper tube 1111 and a temperature detection copper tube 1112. One end of the heating copper tube 1111 and the temperature detection copper tube 1112 is first brazed with a stainless steel sleeve 30.

[0035] The brazing may be performed by welding methods including but not limited to silver-based brazing, induction brazing, etc. In this embodiment, silver-based brazing is used. In specific implementation, high-frequency current induction heating (i.e., induction brazing) may also be used to improve welding efficiency.

[0036] In this embodiment, by first welding the stainless steel collar 30 to one end of the exposed copper tube 111, it is possible to avoid the traditional welding method in which the exposed copper tube 111 is directly welded to the stainless steel plate 21, causing thermal deformation of the stainless steel plate 21, thereby easily leaking the phase change material; in addition, since the stainless steel collar 30 is small, it is not easy to deform when welded to the exposed copper tube 111, and it is also easy to heat up, which greatly reduces the difficulty of brazing and improves the welding efficiency.

[0037] The exposed copper tube 111 and the internal copper tube 112 are expanded into one piece with the heat exchange fin 12 through a tube expansion process.

[0038] In this embodiment, the heat exchanger assembly 10 is manufactured by the tube expansion process, that is, the exposed copper tube 111 and the internal copper tube 112, which are first welded with the stainless steel ring 30, are expanded into one with the heat exchange fin 12 through the tube expansion process, so that the heat exchange fin and the copper tube structure are tightly connected, which can ensure the firmness and sealing between the two. Compared with traditional welding or bonding, it is more reliable and reduces the risk of loosening due to temperature changes or mechanical stress.

[0039] Further, as a preferred implementation manner of the present solution but not a limitation, the step of expanding the exposed copper tube 111 and the internal copper tube 112 into one piece with the heat exchange fin 12 through a tube expansion process further includes the following steps: Making pre-expanded tube workpieces; The pre-expanded tube workpiece is expanded.

[0040] Specifically, the pre-expanded tube workpiece is formed by an exposed copper tube 111 and an internal copper tube 112 welded with a stainless steel collar 30, which are respectively passed through the connection holes 121 of the heat exchange fins 12; In addition, when the pre-expanded tube workpiece is expanded, the copper tube can be expanded by mechanical pressure or thermal force. In this embodiment, mechanical pressure is preferably used to expand the copper tube, that is, in this embodiment, an expansion mold is used to mechanically pressurize the copper tube to increase the diameter of the copper tube to achieve expansion.

[0041] Among them, the expansion mold is a round rod that can penetrate the copper tube. The front end of the round rod is provided with a mold core with a diameter slightly larger than the round rod and a shape similar to an abacus. The specific diameter of the mold core can be designed according to the diameter of the copper tube after expansion, ultimately ensuring that the copper tube can be firmly and tightly connected to the heat exchange fin after expansion.

[0042] The stainless steel collar 30 and the stainless steel plate 21 are welded by argon arc welding.

[0043] Specifically, the heat exchanger assembly 10 formed after tube expansion has a stainless steel collar 30 welded to one end of the exposed copper tube 111. The stainless steel collar 30 is passed through the through hole 211 of the stainless steel plate 21, and the outer wall of the stainless steel collar 30 and the inner wall of the through hole 211 are tightly welded together by argon arc welding to form a complete phase change hot water tank.

[0044] Among them, the argon arc welding is a welding technology that uses argon as a shielding gas. Its principle is to melt two parent materials to be welded (i.e., the stainless steel sleeve ring 30 and the stainless steel plate 21 in this embodiment) through an electric arc. The welding current of the argon arc welding can be determined according to welding factors such as the thickness of the welding parent material and the welding speed.

[0045] In this embodiment, since the stainless steel collar 30 and the stainless steel plate 21 are made of the same material, their physical properties such as melting point, thermal expansion coefficient, thermal conductivity, etc. are similar, which makes it easier to obtain uniform fusion and good welding quality during the welding process, so that the stainless steel plate is not easily deformed during the welding process; In addition, the heat of argon arc welding is concentrated, the heat-affected zone is narrow, and the stress, deformation and crack tendency of the weldment after welding are small, which makes the stainless steel plate at the bottom of the hot water tank less likely to deform during the welding process and has better sealing. At the same time, argon arc welding uses argon as a protective gas, which can isolate harmful gases such as oxygen and nitrogen in the air, prevent oxidation and nitridation of the welding area, and thus make the stainless steel plate less likely to oxidize.

[0046] Please refer to Figure 8 As shown, an embodiment of the present invention also provides another welding method for a phase-change hot water tank, which differs from the aforementioned welding method in that: the exposed copper tube 111 and the internal copper tube 112 are first expanded into one with the heat exchange fin 12 through a tube expansion process, and then the stainless steel sleeve is welded to the exposed copper tube by brazing.

[0047] It should be noted that if the welding method of this embodiment is used, the pre-expanded tube workpiece produced during the tube expansion process is formed by the exposed copper tube 111 and the internal copper tube 112 which are not welded with the stainless steel collar 30, respectively passing through the connection holes 121 of the heat exchange fins 12; In addition, compared with the aforementioned welding method, the welding method of this embodiment is only reflected in expanding the tube first and then welding the stainless steel ring. The core is to avoid direct welding of the copper tube and the stainless steel plate, which causes thermal deformation of the stainless steel plate 21. Therefore, the beneficial effects of the aforementioned welding method also exist in this embodiment.

[0048] The working principle of this embodiment is as follows: The present invention proposes a phase change hot water tank and welding method, wherein a stainless steel collar 30 is welded to one end of an exposed copper tube 111, and then the exposed copper tube 111 welded with the stainless steel collar 30 and the internal copper tube 112 are respectively passed through the connection holes 121 of the heat exchange fins 12 to form a pre-expanded tube workpiece, and then the pre-expanded tube workpiece is expanded by a tube expansion process to form a heat exchanger assembly 10, and finally the exposed copper tube 111 welded with the stainless steel collar 30 in the heat exchanger assembly 10 is passed through the through hole 211 of the stainless steel plate 21, and the stainless steel collar 30 is welded to the stainless steel plate 21 by argon arc welding. The phase change hot water tank manufactured by this welding method can avoid direct welding of the copper tube and the stainless steel plate, which causes thermal deformation of the stainless steel plate 21, thereby easily leaking the phase change material; and because the stainless steel collar 30 and the stainless steel plate 21 are made of the same material, it is easier to obtain uniform fusion and good welding quality during the welding process, so that the stainless steel plate is not easily deformed during the welding process.

[0049] Ordinary technicians in the relevant field should understand that the above is an implementation method provided in combination with specific content, and it is not considered that the specific implementation of the present invention is limited to these descriptions. At the same time, due to different industry naming, it is not limited to the above naming, nor is it limited to English naming. Any similarity or similarity with the method, structure, etc. of the present invention, or a number of technical deductions or substitutions made on the premise of the concept of the present invention, should be regarded as the protection scope of the present invention.

Claims

1. A phase change hot water tank, characterized in that: The invention comprises a heat exchanger assembly (10) and a box (20) for encapsulating the heat exchanger assembly (10), wherein the heat exchanger assembly (10) comprises a copper tube structure (11) for heating water in a hot water tank and capable of monitoring the water temperature, and the box (20) comprises a stainless steel plate (21) arranged at the bottom, the stainless steel plate (21) being provided with a through hole (211) for the copper tube structure (11) to pass through for connection with external equipment, and a stainless steel collar (30) for preventing the stainless steel plate (21) from deforming during welding is provided at the connection between the copper tube structure (11) and the through hole (211).

2. A phase change hot water tank according to claim 1, characterized in that: The copper tube structure (11) comprises an exposed copper tube (111) and an internal copper tube (112); one end of the exposed copper tube (111) passing through the through hole (211) is welded with the stainless steel sleeve ring (30).

3. A phase change hot water tank according to claim 2, characterized in that: The exposed copper tubes (111) include a plurality of heating copper tubes (1111) for heating water in the hot water tank and a plurality of temperature detection copper tubes (1112) for monitoring the water temperature in the hot water tank.

4. A phase change hot water tank according to claim 2, characterized in that: The built-in copper tube (112) comprises a plurality of heat exchange copper tubes (1121) for conducting heat in the hot water tank, and the heat exchange copper tube (1121) is a U-shaped copper tube.

5. A phase change hot water tank according to claim 1, characterized in that: The heat exchanger assembly (10) further comprises heat exchange fins (12) for improving heat transfer efficiency, and the heat exchange fins (12) and the copper tube structure (11) are expanded into one piece.

6. A phase change hot water tank according to claim 5, characterized in that: The heat exchange fin (12) is punched with a plurality of connection holes (121) for the copper tube structure (11) to pass through for tube expansion connection.

7. A phase change hot water tank according to claim 1, characterized in that: The box body (20) further comprises a fixing member (22) for improving the connection tightness of the stainless steel plate (21); the fixing member (22) is a stainless steel hoop.

8. A phase change hot water tank according to claim 5, characterized in that: The through hole (211) and the connecting hole (121) are both flanging holes.

9. A welding method for a phase change hot water tank, characterized in that: For manufacturing a phase change hot water tank as claimed in any one of claims 1 to 8, the welding method comprises: The stainless steel sleeve ring (30) and the exposed copper tube (111) are brazed; The exposed copper tube (111) and the internal copper tube (112) are expanded into one piece with the heat exchange fin (12) through a tube expansion process; The stainless steel collar (30) and the stainless steel plate (21) are welded by argon arc welding.

10. A welding method for a phase change hot water tank according to claim 9, characterized in that: The step of expanding the exposed copper tube (111) and the internal copper tube (112) into one piece with the heat exchange fin (12) through a tube expansion process further includes the following steps: Making pre-expanded tube workpieces; The pre-expanded tube workpiece is expanded.

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