Welding device and welding method for heat exchange tube of heat exchanger

Abstract

The invention relates to the field of welding machining, in particular to a welding device and method for a heat exchange tube of a heat exchanger, and the welding device for the heat exchange tube of the heat exchanger comprises a mounting frame, an end support and a welding arm; a vertical limiting groove with the upper end penetrating through the end support is formed in the end support and used for receiving the horizontally-falling heat exchange tube. A plurality of hoop units are arranged in the limiting groove in the vertical direction at intervals. The hoop unit has a relaxed state and a clasped state, and in the relaxed state, the heat exchange tube can continuously fall off the hoop unit; in the holding state, the heat exchange tube can be clamped; the hoop units in the limiting grooves are sequentially switched from the loose state to the tight holding state from bottom to top, so that the heat exchange tubes falling into the limiting grooves are sequentially clamped, and operation is easy. And the hoop units are arranged in the end supports to support the heat exchange tubes, the ends of the heat exchange tubes can be located in the centers of the holes in the tube plate, the heat exchange tubes are limited, and the situation that the heat exchange tubes move in the welding process, and the welding effect is affected is avoided.

Description

Technical Field

[0001] The present invention relates to the field of welding processing, and in particular to a heat exchange tube welding device and a welding method for a heat exchanger. Background Art

[0002] Shell-and-tube heat exchangers, core equipment in industries such as petrochemicals, nuclear power, and refrigeration, are crucial for operational reliability. The joints between the heat exchange tubes and the tubesheet are one of the heat exchanger's weakest links, directly determining the equipment's pressure-bearing capacity, fatigue resistance, and corrosion resistance. Failure can lead to media mixing, resulting in serious production accidents and economic losses.

[0003] Traditional connection methods primarily include expansion joints, welding, and a combination of expansion and welding. Welding, due to its excellent airtightness and high strength, is the preferred method for high-temperature and high-pressure applications. Before welding, the heat exchange tubes are typically manually inserted between the two tube sheets, resting against the holes in the tube sheets. The tubes' axial position relative to the tube sheets is then adjusted to ensure a good weld. While simple, this method is subject to significant manual placement errors and is inefficient. Using the tube sheet holes to support the heat exchange tubes can lead to uneven welds and can easily cause shaking during welding, impacting weld quality. Summary of the Invention

[0004] The present invention provides a heat exchange tube welding device and a welding method for a heat exchanger, so as to solve the problem in the prior art that large placement errors during heat exchange tube welding affect welding quality.

[0005] The heat exchange tube welding device of a heat exchanger of the present invention adopts the following technical solution: A heat exchange tube welding device for a heat exchanger, used for welding the two ends of a plurality of heat exchange tubes to the holes on two tube sheets respectively, comprising a mounting bracket, an end bracket and a welding arm; the tube sheet is mounted on the mounting bracket, and the normal of the tube sheet is horizontal and can be moved relative to the mounting bracket in a first direction, the first direction being the normal direction of the tube sheet; there are two end brackets, which are located between the two tube sheets and distributed in sequence along the first direction; a vertical limiting groove is provided on the end bracket, the upper end of which passes through the end bracket, for receiving the horizontally dropped heat exchange tube; a plurality of clamp units are arranged at intervals in the vertical direction in the limiting groove, each clamp unit comprises two first clamps and two second clamps, the first clamp is located on the lower side of the second clamp, and the second clamp is both rotatably mounted on the end The bracket can form a cylindrical structure with an axis along the first direction after rotation, and the two ends of the heat exchange tube that falls into the limiting groove do not exceed the ends of the cylindrical structure of the clamp unit of the two end brackets that are far away from each other; the clamp unit has a relaxed state and a clamped state. In the relaxed state, the heat exchange tube can pass between the two second clamps, and push the two first clamps to rotate and then pass through the clamp unit to continue falling; in the clamped state, the two first clamps rotate under the action of gravity of the falling heat exchange tube, and drive the two second clamps to approach each other, and work together with the two second clamps to clamp the heat exchange tube; multiple clamp units in the limiting groove switch from the relaxed state to the clamped state from bottom to top in sequence; the welding arm welds the installed heat exchange tube and tube sheet.

[0006] Optionally, the first clamp and the second clamp are both arc-shaped structures with axes along the first direction, and one end of the arc structure is rotatably installed on the end bracket around the axis of the first direction, and a first transmission wheel is installed on the rotating shaft of the first clamp, and a transmission sleeve is installed on the rotating shaft of the second clamp, and a retractable transmission rod is slidably installed in the transmission sleeve along the first direction, and the transmission rod rotates synchronously with the transmission sleeve, and one end of the transmission rod extends out of the ends of the two end brackets facing away from each other, and one end of the extended end bracket is provided with a tapered portion; a second transmission wheel and a third transmission wheel are rotatably installed on the end bracket, and the second transmission wheel cooperates with the first transmission wheel for transmission, and the third transmission wheel is a tapered wheel for transmission cooperation with the tapered portion; when the clamp unit is in a relaxed state, the third transmission wheel disengages from the tapered portion, and in a tightened state, the tapered portion of the transmission rod cooperates with the third transmission wheel for transmission.

[0007] Optionally, a heat exchange tube welding device of a heat exchanger also includes two top pressure plates, which are respectively located on the side of the two end brackets away from each other, each top pressure plate is located between an end bracket and a tube plate, and the top pressure plate can be slidably installed on the mounting frame along a first direction; a first elastic member is provided between the transmission rod and the transmission sleeve, and the first elastic member enables multiple transmission rods to extend out of one end of the end bracket in the initial state and be located in the same vertical plane; a plurality of top pressure rods corresponding to the clamp units are fixed on the side of the top pressure plate close to the end bracket, the first top pressure rod is used to abut against the transmission rod, and the lengths of the multiple top pressure rods in the first direction decrease successively from bottom to top.

[0008] Optionally, the transmission rod includes an outer tube, an inner rod and a second elastic member. One end of the outer tube and the inner rod are slidably sleeved along a first direction and connected through the second elastic member. The outer tube slides and rotates synchronously with the transmission sleeve, and the inner rod is used to abut against the push rod; the elastic force of the second elastic member is greater than the elastic force of the first elastic member.

[0009] Optionally, a heat exchange tube welding device of a heat exchanger also includes an intermediate bracket, which is located between the two end brackets and fixed to the mounting bracket. The intermediate bracket is provided with a card slot corresponding to the limit slot in the first direction, and the upper end of the card slot is connected to the upper end surface of the intermediate bracket.

[0010] Optionally, the first clamp includes a clamp frame and multiple rollers rotatably mounted on the clamp frame, one side of the clamp frame is rotatably mounted on the end bracket around an axis in the first direction, the multiple rollers are all arranged along the first direction, and are spaced apart along an arc track on the clamp frame, and the axis of the arc track is along the first direction; a linkage assembly is provided between the clamp frame and the intermediate bracket, and the linkage assembly causes the multiple rollers to rotate when the end bracket and the intermediate bracket approach each other, thereby cleaning the outer peripheral wall of the heat exchange tube.

[0011] Optionally, the linkage assembly includes a linkage rod fixed on the intermediate bracket and a linkage tube rotatably mounted on the clamp frame, the linkage tube is spirally matched with the linkage rod, and the linkage tube is connected to the multiple rollers through a transmission belt for transmission.

[0012] Optionally, a spiral groove is provided on the outer peripheral wall of the roller shaft to guide debris on the heat exchange tube to fall off.

[0013] Optionally, there are multiple limiting grooves, which are arranged in sequence and spaced apart along the horizontal direction perpendicular to the heat exchange tube, and there are multiple corresponding card slots.

[0014] A heat exchange tube welding method for a heat exchanger, using the heat exchange tube welding device for a heat exchanger, comprises the following steps: S10, the heat exchange tubes fall horizontally along the first direction to the limiting grooves, and before each heat exchange tube falls, one clamp unit is switched from bottom to top to a clamping state; S20, after all heat exchange tubes are installed, the two end brackets are synchronously moved closer to each other so that both ends of the heat exchange tube extend relative to the clamp unit and the end bracket; S30, moving the tube sheet so that the holes on the tube sheet correspond to the heat exchange tubes; S40, the welding arm welds the tube sheet and the heat exchange tube.

[0015] The beneficial effect of the present invention is that the heat exchange tube welding device of the heat exchanger of the present invention switches the clamp units in the limit groove from a loose state to a clamped state from bottom to top, so that the heat exchange tubes falling into the limit groove are clamped in sequence, without the need for manual locking one by one, and the operation is simple.

[0016] Furthermore, by providing a clamp unit within the end bracket to support the heat exchange tube, the end of the heat exchange tube can be positioned at the center of the hole in the tube sheet. Compared with the existing method of placing the end of the heat exchange tube within the tube sheet hole before welding, the weld is more uniform and the weld quality is higher. The clamp unit also limits the position of the heat exchange tube, preventing it from moving during the welding process and affecting the welding effect.

[0017] Furthermore, when the two end brackets approach each other, the position of the heat exchange tube in the first direction is adjusted by utilizing the difference in contact area between the clamp unit and the heat exchange tube, so that the lengths of the two ends of the heat exchange tube extending out of the two end brackets are consistent, and the relative positions of the two ends and the two tube sheets are consistent, thereby ensuring the welding consistency of the two tube sheets and the heat exchange tube.

[0018] Furthermore, when the heat exchange tube initially falls into the limit groove and is clamped by the clamp unit, its end is located in the cylindrical structure of the clamp unit. When the end bracket moves to make the end of the heat exchange tube extend out of the end bracket, the first clamp and the second clamp produce friction cleaning on the end of the heat exchange tube to ensure the matching effect between the end of the heat exchange tube and the holes on the tube plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a heat exchange tube welding device for a heat exchanger according to the present invention; Figure 2 A schematic diagram of a portion of the structure of an embodiment of a heat exchange tube welding device for a heat exchanger according to the present invention; Figure 3 for Figure 2A magnified schematic diagram of point A in the middle; Figure 4 for Figure 2 Side view of Figure 5 for Figure 4 A magnified schematic diagram of point B in the middle; Figure 6 This is a schematic diagram of the coordination of the end bracket and the heat exchange tube in an embodiment of a heat exchange tube welding device for a heat exchanger of the present invention (only one set of clamp units is shown in the figure); Figure 7 for Figure 6 Enlarged schematic diagram of point C in the middle; Figure 8 for Figure 6 Front view of the device (the clamp unit is in a clamped state); Figure 9 for Figure 8 Schematic diagram of the cross section along the middle DD direction; Figure 10 for Figure 9 The enlarged schematic diagram of point E in the middle; Figure 11 This is a structural schematic diagram of a first clamp in an embodiment of a heat exchange tube welding device for a heat exchanger of the present invention; Figure 12 for Figure 8 Schematic diagram of another state (the hoop unit is in a relaxed state in the figure); Figure 13 for Figure 12 Enlarged schematic diagram of point F in the middle.

[0021] In the figure: 100, mounting frame; 110, moving platform; 200, end bracket; 210, limiting groove; 220, second transmission wheel; 230, third transmission wheel; 300, intermediate bracket; 310, slot; 400, clamp unit; 410, first clamp; 411, first transmission wheel; 412, roller; 413, clamp frame; 420, second clamp; 421, transmission sleeve; 422, first elastic member; 430, transmission rod; 431, outer tube; 432, inner rod; 433, second elastic member; 441, linkage rod; 442, linkage tube; 500, tube sheet; 600, heat exchange tube; 700, top pressure plate; 710, top pressure rod; 800, welding arm. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0023] An embodiment of a heat exchange tube welding device of a heat exchanger of the present invention is used to weld the two ends of a plurality of heat exchange tubes 600 to the holes on two tube sheets 500, such as Figures 1 to 13 As shown, it includes a mounting frame 100 and an end bracket 200 .

[0024] The tube sheet 500 is mounted on the mounting frame 100 , with the normal line of the tube sheet 500 being horizontal, and can move relative to the mounting frame 100 along a first direction, where the first direction is the normal line direction of the tube sheet 500 .

[0025] Two end brackets 200 are located between the two tube sheets 500 and arranged sequentially along a first direction. Each end bracket 200 is provided with a vertically disposed retaining groove 210 extending in the first direction. The upper ends of the retaining grooves 210 are connected to the upper end of the end bracket 200, and are used to receive the horizontally dropped heat exchange tubes 600. Multiple clamping units 400 are vertically spaced apart within the retaining grooves 210 of the end bracket 200. Each clamping unit 400 includes two first clamps 410 and two second clamps 420. The first clamps 410 are located below the second clamps 420 and are both rotatably mounted on the end bracket 200. After rotation, the first and second clamps 410, 420 form a cylindrical structure with an axis along the first direction. The ends of the heat exchange tube 600 that falls into the retaining grooves 210 do not extend beyond the ends of the cylindrical structures of the clamping units 400 of the two end brackets 200, which are separated from each other. The clamp unit 400 has a relaxed state and a clamped state. In the relaxed state, the heat exchange tube 600 can pass between the two second clamps 420, and push the two first clamps 410 to rotate and then pass through the clamp unit 400 to continue falling; in the clamped state, the two first clamps 410 rotate under the action of gravity of the falling heat exchange tube 600, and drive the two second clamps 420 to approach each other, and work together with the two second clamps 420 to clamp the heat exchange tube 600; the multiple clamp units 400 in the limit groove 210 switch from the relaxed state to the clamped state from bottom to top.

[0026] The welding arm 800 welds the installed heat exchange tube 600 and the tube sheet 500 .

[0027] The mounting frame 100 is mounted on a liftable mobile platform 110. Mobile platform 110 is movable along a guide rail laid on the ground and employs a scissor-type lifting mechanism, commonly found in the prior art. Its movement is driven by a linear motor. The lifting and movement of mobile platform 110 adjusts the position of mounting frame 100 and its end brackets 200, enabling them to receive heat exchange tubes 600 dropped from an external hopper (not shown). The heat exchange tubes 600 then fall into the retaining grooves 210 and are subsequently clamped, from bottom to top, by the clamping units 400 within the retaining grooves 210. Specifically, before dropping the first heat exchange tube 600, the lowest clamping unit 400 in the limiting groove 210 is first switched to a clamped state, while the other clamping units 400 are in a relaxed state. After the horizontally falling heat exchange tube 600 passes through the relaxed clamping unit 400, it pushes the first clamping unit 410 of the lowest clamping unit 400 to rotate, thereby driving the second clamping unit 420 to rotate and clamp the heat exchange tube 600. Before dropping the second heat exchange tube 600, the second clamping unit 400 from the bottom up is also switched to a clamped state, thereby clamping the second heat exchange tube 600 dropped into the limiting groove 210. This process is repeated until each clamping unit 400 has clamped a corresponding heat exchange tube 600. The ends of the heat exchange tube 600 that falls on the two end brackets 200 do not exceed the cylindrical structure of the clamp unit 400. When the center of the heat exchange tube 600 is offset from the distribution center of the clamp units 400 of the two end brackets 200, the contact lengths of the clamp units 400 of the two end brackets 200 with the heat exchange tube 600 in the first direction are different, and thus the contact areas with the heat exchange tube 600 are different. When the two end brackets 200 approach each other so that the two ends of the heat exchange tube 600 extend out and the two end brackets 200 move away from each other, the clamp unit 400 of the end bracket 200 with a larger contact area with the heat exchange tube 600 will push the clamped heat exchange tube 600 to move to the other side until the contact areas of the clamp units 400 of the two end brackets 200 with the heat exchange tube 600 are the same. When the two end brackets 200 continue to approach each other, the heat exchange tube 600 does not move in the axial direction. After both ends of the heat exchange tube 600 extend out of the two end brackets 200 , the two tube sheets 500 are moved so that the holes of the tube sheets 500 correspond to the heat exchange tube 600 , which facilitates subsequent welding.

[0028] By switching the clamping unit 400 in the limiting groove 210 from a loose state to a tightened state from bottom to top, the heat exchange tube 600 that falls into the limiting groove 210 is clamped in sequence, eliminating the need for manual locking one by one, making operation simple. Furthermore, by providing the clamping unit 400 in the end bracket 200 to support the heat exchange tube 600, the end of the heat exchange tube 600 can be positioned at the center of the hole in the tube sheet 500. Compared to the prior art method of placing the end of the heat exchange tube 600 in the hole of the tube sheet 500 before welding, the weld is more uniform and the welding quality is higher. The clamping unit 400 can also limit the position of the heat exchange tube 600, preventing it from moving during the welding process, which could affect the welding effect. Furthermore, as the two end brackets 200 approach each other, the different contact areas between the clamp unit 400 and the heat exchange tube 600 are utilized to adjust the position of the heat exchange tube 600 in the first direction, so that the lengths of the ends of the heat exchange tube 600 extending from the two end brackets 200 are consistent, and the relative positions of the ends and the two tube sheets 500 are consistent, thereby ensuring the consistency of the welding between the two tube sheets 500 and the heat exchange tube 600. Furthermore, when the heat exchange tube 600 initially falls into the limiting groove 210 and is clamped by the clamp unit 400, its end is located within the cylindrical structure of the clamp unit 400. As the end bracket 200 moves to extend the end of the heat exchange tube 600 from the end bracket 200, the first clamp 410 and the second clamp 420 generate friction and cleaning on the end of the heat exchange tube 600, ensuring the effective fit between the end of the heat exchange tube 600 and the hole in the tube sheet 500.

[0029] In this embodiment, the first clamp 410 and the second clamp 420 are both arc-shaped structures with axes extending along a first direction. One end of the arc-shaped structure is rotatably mounted on the end bracket 200 about the axis in the first direction. A third elastic member is disposed between the first clamp 410 and the end bracket 200. The third elastic member forces the two first clamps 410 to initially be positioned along the descending path of the heat exchange tube 600. A first transmission wheel 411 is mounted on the rotating shaft of the first clamp 410. A fourth elastic member is disposed between the second clamp 420 and the end bracket 200. The fourth elastic member forces the two second clamps 420 to rotate away from each other without affecting the descent of the heat exchange tube 600. Preferably, both the third and fourth elastic members are torsion springs. A transmission sleeve 421 is mounted on the rotating shaft of the second clamping hoop 420. A retractable transmission rod 430 is mounted within the transmission sleeve 421, slidingly mounted in a first direction. The transmission rod 430 rotates synchronously with the transmission sleeve 421. One end of the transmission rod 430 extends beyond the ends of the two end brackets 200 facing away from each other, and one end of the extended end bracket 200 is provided with a tapered portion. Two sets of coaxial and fixedly connected second and third transmission wheels 220 and 230 are rotatably mounted on the end brackets 200, each set corresponding to the transmission between the first clamping hoop 410 and the second clamping hoop 420. The second transmission wheel 220 cooperates with the first transmission wheel 411 for transmission, while the third transmission wheel 230 is a tapered wheel designed to mate with the tapered portion. When the clamping hoop unit 400 is in a relaxed state, the third transmission wheel 230 disengages from the tapered portion, and the rotation of the first clamping hoop 410 is not transmitted to the second clamping hoop 420, which maintains its initial position. When the clamp unit 400 is in the clamped state, the tapered portion of the transmission rod 430 cooperates with the third transmission wheel 230 to transmit the rotation of the first clamp 410 to the second clamp 420, causing the second clamp 420 to rotate and work together with the first clamp 410 to clamp the heat exchange tube 600. The first transmission wheel 411 and the second transmission wheel 220 are cylindrical and are both friction wheels or gears. The third transmission wheel 230 and the tapered portion are both conical wheels and are both friction wheels or gears.

[0030] In this embodiment, a heat exchange tube welding device for a heat exchanger further includes two top pressure plates 700, each located on a side of two end brackets 200 that are spaced apart from each other. Each top pressure plate 700 is located between an end bracket 200 and a tube sheet 500. The top pressure plates 700 can be slidably mounted on the mounting frame 100 along a first direction. A clearance groove is reserved on the top pressure plates 700 to allow the heat exchange tubes 600 to pass through. A first elastic member 422 is disposed between each transmission rod 430 and the transmission sleeve 421. The first elastic member 422 ensures that the ends of the multiple transmission rods 430 extending from the end bracket 200 are located on the same vertical plane in the initial state. A plurality of pressure rods 710 corresponding to the clamp units 400 are fixed on one side of the pressure plate 700 close to the end bracket 200. The pressure rods 710 are used to abut against the transmission rod 430, and the lengths of the plurality of pressure rods 710 in the first direction decrease successively from bottom to top, and then when the pressure plate 700 approaches the end bracket 200, the pressure rods 710 of the plurality of clamp units 400 are pushed successively from bottom to top.

[0031] In this embodiment, the transmission rod 430 includes an outer tube 431, an inner rod 432, and a second elastic member 433. One end of the outer tube 431 and the inner rod 432 are slidably coupled in a first direction and connected by the second elastic member 433. The outer tube 431 and the transmission sleeve 421 slide and rotate synchronously, and the inner rod 432 is configured to abut against the push rod 710. The elastic force of the second elastic member 433 is greater than the elastic force of the first elastic member 422. The transmission rod 430 is configured as a retractable elastic structure, so that after the lowermost push rod 710 abuts the transmission rod 430, the push plate 700 can still contract by squeezing the transmission rod 430, thereby continuing to move closer to the end bracket 200.

[0032] In this embodiment, a heat exchange tube welding device for a heat exchanger further includes an intermediate bracket 300, which is positioned between the two end brackets 200 and fixed to the mounting frame 100. The intermediate bracket 300 is provided with a slot 310 corresponding to the limiting slot 210 in the first direction. The upper end of the slot 310 is connected to the upper end surface of the intermediate bracket 300. The intermediate bracket 300 serves as a guide support for the middle portion of the heat exchange tube 600.

[0033] In this embodiment, the first clamp 410 includes a clamp frame 413 and a plurality of rollers 412 rotatably mounted on the clamp frame 413. One side of the clamp frame 413 is rotatably mounted on the end bracket 200 around an axis in the first direction. The plurality of rollers 412 are all arranged along the first direction and are spaced apart along an arc trajectory on the clamp frame 413, and the axis of the arc trajectory is along the first direction. A linkage assembly is provided between the clamp frame 413 and the intermediate bracket 300. The linkage assembly rotates the plurality of rollers 412 when the end bracket 200 and the intermediate bracket 300, thereby cleaning the outer peripheral wall of the heat exchange tube 600.

[0034] In this embodiment, the linkage assembly includes a linkage rod 441 fixed to the intermediate bracket 300 and a linkage tube 442 rotatably mounted on the clamp frame 413. The linkage tube 442 is screwed together with the linkage rod 441 and connected to the multiple rollers 412 via a transmission belt. As the end bracket 200 moves toward the intermediate bracket 300, the linkage tube 442 rotates in conjunction with the linkage rod 441, which in turn drives the multiple rollers 412 via the transmission belt. This not only reduces friction between the rollers 412 and the heat exchange tubes 600, but also scrapes and cleans the outer surface of the heat exchange tubes 600.

[0035] In this embodiment, a spiral groove is formed on the outer wall of the roller shaft 412 to guide the debris on the heat exchange tube 600 to fall off.

[0036] In this embodiment, there are multiple limiting grooves 210, which are sequentially spaced apart along a horizontal direction perpendicular to the heat exchange tube 600, corresponding to multiple locking grooves 310. Each limiting groove 210 corresponds to a row of holes on the tube sheet 500.

[0037] In this embodiment, the movement of the end supports 200, the top pressure plate 700, and the tube sheet 500 can all be driven by hydraulic cylinders or pneumatic cylinders, or by a motor through a screw-nut mechanism. To ensure that the two end supports 200 can move synchronously toward the middle support 300, each end support 200 can be connected to a rack, and the two racks can be meshed with the same gear located between them. Driving one end support 200 toward the middle support 300 can drive the other end support 200 to move synchronously toward the middle support 300. The tube sheet 500 is typically a circular plate and requires the installation of two separate gussets to clamp it. The movement of the gussets drives the synchronous movement of the tube sheet 500. The gussets are a common structure in the prior art and will not be described in detail.

[0038] Before using the heat exchange tube welding device of the heat exchanger of the present invention, the spacing between the two end brackets 200 is adjusted according to the length of the heat exchange tube 600, and the two end brackets 200, the two top pressure plates 700 and the two tube sheets 500 are symmetrically arranged with respect to the spacing of the middle bracket 300. By lifting and moving the mobile platform 110, the positions of the mounting frame 100 and the end bracket 200 installed on the mounting frame 100 are adjusted, so that the end bracket 200 on the mounting frame 100 can receive the heat exchange tube 600 dropped from the external hopper (not shown in the figure), and the heat exchange tube 600 extends along the first direction and falls into the limiting groove 210 in sequence. Before dropping the first heat exchange tube 600, the top pressure plate 700 is moved to make it close to its corresponding end bracket 200, and the top pressure rod 710 on the top pressure plate 700 pushes the transmission rod 430 on the lowest clamping unit 400, so that the tapered portion of the transmission rod 430 cooperates with the third transmission wheel 230, and the lowest clamping unit 400 switches to the clamping state. As the falling heat exchange tube 600 passes over the multiple relaxed clamping units 400 above, it pushes the first clamping hoop 410 of each clamping hoop unit 400, causing it to rotate and continue to fall. When it lands on the two first clamping hoops 410 of the lowest clamping hoop unit 400, it pushes the two first clamping hoops 410 to rotate. The first transmission wheel 411 of the first clamping hoop 410 rotates, driving the second transmission wheel 220 and the third transmission wheel 230 to rotate. The third transmission wheel 230 drives the transmission sleeve 421 to rotate, which in turn drives the two second clamping hoops 420 to rotate. Together with the first clamping hoop 410, it forms a cylindrical structure to clamp the heat exchange tube 600. Before the next heat exchange tube 600 is dropped, the top pressure plate 700 is moved, causing the second clamping hoop unit 400 from the bottom to also switch to a clamped state, thereby clamping the second heat exchange tube 600 that has fallen into the limiting groove 210. This process continues in this manner until each clamping hoop unit 400 has clamped a corresponding heat exchange tube 600.

[0039] Because the spacing between the two end brackets 200 has been pre-adjusted, the ends of the heat exchange tubes 600 that fall into the limiting grooves 210 are guaranteed to not extend beyond the ends of the cylindrical structures of the clamp units 400 of the two end brackets 200. After the heat exchange tubes 600 are fully installed on the end brackets 200, the two end brackets 200 are moved closer together, and the two top pressure plates 700 move synchronously with their corresponding end brackets 200. When the center of the heat exchange tube 600 is offset from the distribution center of the clamping units 400 of the two end brackets 200, the contact lengths of the clamping units 400 of the two end brackets 200 with the heat exchange tube 600 in the first direction are different, and thus the contact areas with the heat exchange tube 600 are different. When the two end brackets 200 approach each other, so that the ends of the heat exchange tube 600 extend out and the two end brackets 200 move away from each other, the clamping units 400 of the end bracket 200 with a larger contact area with the heat exchange tube 600 will push the clamped heat exchange tube 600 toward the other side until the contact areas of the clamping units 400 of the two end brackets 200 with the heat exchange tube 600 are the same. As the two end brackets 200 continue to approach each other, the heat exchange tube 600 does not move axially. The two tube sheets 500 are then moved closer together so that the holes in each tube sheet 500 correspond to one end of the heat exchange tube 600, and the welding arm 800 welds the tube sheets 500 and the heat exchange tube 600.

[0040] After welding is completed, the top pressure plate 700 moves away from its corresponding end bracket 200, causing the transmission rod 430 to extend under the action of the first elastic member 422, thereby disengaging the tapered portion from the third transmission wheel 230. The second clamping hoop 420 rotates under the action of the fourth elastic member, and the two second clamping hoops 420 rotate and open. The two first clamping hoops 410, under the action of the third elastic member, allow the heat exchange tube 600 to move up and down relative to the clamping unit 400. As the end bracket 200 moves downward relative to the heat exchange tube 600, the heat exchange tube 600 pushes the two first clamping hoops 410 above it, further rotating upward to stretch the third elastic member, and then passes between the two first clamping hoops 410. Specifically, the gusset plate that secures the tube sheet 500 can be removed from the mounting frame 100. After the welded heat exchange tube 600 and tube sheet 500 are lifted, the lifting platform is used to drive the end bracket 200, the intermediate bracket 300, and the top pressure plate 700 to move downward synchronously and disengage from the heat exchange tube 600.

[0041] The present invention also provides an embodiment of a heat exchange tube welding method for a heat exchanger, using the heat exchange tube welding device of the heat exchanger, comprising the following steps: S10, the heat exchange tubes 600 fall horizontally along the first direction to the limiting groove 210, and before each heat exchange tube 600 falls, one clamp unit 400 is switched from bottom to top to a clamping state; S20, after all heat exchange tubes 600 are installed, the two end brackets 200 are synchronously moved closer to each other so that both ends of the heat exchange tube 600 extend relative to the clamp unit 400 and the end bracket 200; S30, moving the tube sheet 500 so that the holes on the tube sheet 500 correspond to the heat exchange tubes 600; S40 , the welding arm 800 welds the tube sheet 500 and the heat exchange tube 600 .

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A heat exchange tube welding device for a heat exchanger, used to weld the ends of multiple heat exchange tubes to holes on two tube sheets, characterized in that: Includes mounting frame, end brackets and welding arms; The tube sheet is mounted on the mounting frame, and the normal line of the tube sheet is horizontal, and the tube sheet can move relative to the mounting frame along a first direction, where the first direction is the normal line direction of the tube sheet; There are two end brackets, which are located between the two tube sheets and distributed in sequence along the first direction; a vertical limiting groove is provided on the end bracket, and the upper end of the limiting groove passes through the end bracket, which is used to receive the horizontally dropped heat exchange tube; a plurality of clamp units are arranged at intervals along the vertical direction in the limiting groove, and each clamp unit includes two first clamps and two second clamps, the first clamp is located on the lower side of the second clamp, and the second clamp is rotatably installed on the end bracket, and can form a cylindrical structure with an axis along the first direction after rotation, and the two ends of the heat exchange tube falling into the limiting groove do not exceed two The cylindrical structures of the clamp units of the end brackets are separated from each other at one end; the clamp unit has a relaxed state and a tightened state. In the relaxed state, the heat exchange tube can pass between the two second clamps and push the two first clamps to rotate and then pass through the clamp unit to continue falling; in the tightened state, the two first clamps rotate under the action of gravity of the falling heat exchange tube and drive the two second clamps to approach each other, and work together with the two second clamps to clamp the heat exchange tube; the multiple clamp units in the limit groove switch from the relaxed state to the tightened state from bottom to top in sequence; The welding arm welds the installed heat exchange tubes to the tube sheet.

2. The heat exchange tube welding device of a heat exchanger according to claim 1, characterized in that: The first clamp and the second clamp are both arc-shaped structures with their axes along the first direction, and one end of the arc structure is rotatably installed on the end bracket around the axis of the first direction, and a first transmission wheel is installed on the rotating shaft of the first clamp, and a transmission sleeve is installed on the rotating shaft of the second clamp, and a retractable transmission rod is slidably installed in the transmission sleeve along the first direction, and the transmission rod rotates synchronously with the transmission sleeve, and one end of the transmission rod extends out of the ends of the two end brackets facing away from each other, and one end of the extended end bracket is provided with a tapered portion; a second transmission wheel and a third transmission wheel are rotatably installed on the end bracket that are coaxial and fixedly connected, and the second transmission wheel cooperates with the first transmission wheel for transmission, and the third transmission wheel is a tapered wheel for transmission cooperation with the tapered portion; when the clamp unit is in a relaxed state, the third transmission wheel disengages from the tapered portion, and in a tightened state, the tapered portion of the transmission rod cooperates with the third transmission wheel for transmission.

3. The heat exchange tube welding device of a heat exchanger according to claim 2, characterized in that: It also includes two top pressure plates, which are respectively located on the side of the two end brackets away from each other, each top pressure plate is located between an end bracket and a tube plate, and the top pressure plate can be slidably installed on the mounting frame along a first direction; a first elastic member is provided between the transmission rod and the transmission sleeve, and the first elastic member enables multiple transmission rods to extend out of one end of the end bracket in the initial state and be located on the same vertical plane; a plurality of top pressure rods corresponding to the clamp units are fixed on the side of the top pressure plate close to the end bracket, the first top pressure rod is used to abut against the transmission rod, and the lengths of the multiple top pressure rods in the first direction decrease successively from bottom to top.

4. The heat exchange tube welding device of a heat exchanger according to claim 3, characterized in that: The transmission rod includes an outer tube, an inner rod and a second elastic member. One end of the outer tube and the inner rod are slidably sleeved along a first direction and connected through the second elastic member. The outer tube and the transmission sleeve slide and rotate synchronously. The inner rod is used to abut against the push rod; the elastic force of the second elastic member is greater than the elastic force of the first elastic member.

5. The heat exchange tube welding device of a heat exchanger according to claim 1, characterized in that: It also includes an intermediate bracket, which is located between the two end brackets and fixed to the mounting bracket. The intermediate bracket is provided with a card slot corresponding to the limit slot in the first direction, and the upper end of the card slot is connected to the upper end surface of the intermediate bracket.

6. The heat exchange tube welding device of a heat exchanger according to claim 5, characterized in that: The first clamp includes a clamp frame and multiple rollers rotatably mounted on the clamp frame. One side of the clamp frame is rotatably mounted on the end bracket around an axis in the first direction. The multiple rollers are all arranged along the first direction and are spaced apart along an arc track on the clamp frame. The axis of the arc track is along the first direction. A linkage component is provided between the clamp frame and the intermediate bracket. The linkage component rotates the multiple rollers when the end bracket and the intermediate bracket approach each other, thereby cleaning the outer peripheral wall of the heat exchange tube.

7. The heat exchange tube welding device of a heat exchanger according to claim 6, characterized in that: The linkage assembly includes a linkage rod fixed on the middle bracket and a linkage tube rotatably mounted on the clamp frame. The linkage tube is spirally matched with the linkage rod, and the linkage tube is connected to multiple rollers through a transmission belt for transmission.

8. The heat exchange tube welding device of a heat exchanger according to claim 6, characterized in that: The outer wall of the roller is provided with a spiral groove to guide the debris on the heat exchange tube to fall off.

9. The heat exchange tube welding device of a heat exchanger according to claim 5, characterized in that: There are a plurality of limiting grooves, which are sequentially spaced apart along a horizontal direction perpendicular to the heat exchange tube, and there are a plurality of corresponding clamping slots.

10. A heat exchange tube welding method for a heat exchanger, using a heat exchange tube welding device for a heat exchanger according to any one of claims 1 to 9, characterized in that: The following steps are involved: S10, the heat exchange tubes fall horizontally along the first direction to the limiting grooves, and before each heat exchange tube falls, a clamp unit is switched from bottom to top to a clamping state; S20, after all heat exchange tubes are installed, the two end brackets are synchronously moved closer to each other so that both ends of the heat exchange tube extend relative to the clamp unit and the end bracket; S30, moving the tube sheet so that the holes on the tube sheet correspond to the heat exchange tubes; S40, the welding arm welds the tube sheet and the heat exchange tube.

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