A welding apparatus and welding method for heat exchanger tubes.

Abstract

This invention relates to the field of welding processing, specifically to a welding device and method for welding heat exchanger tubes. The welding device includes a mounting frame, an end support, and a welding arm. The end support has a vertical limiting groove extending through it at its upper end to receive horizontally falling heat exchanger tubes. Multiple clamping units are spaced vertically within the limiting groove. Each clamping unit has a relaxed state and a tightened state. In the relaxed state, the heat exchanger tube continues to fall, supported by the clamping unit. In the tightened state, the heat exchanger tube is clamped. By sequentially switching the clamping units in the limiting groove from the relaxed state to the tightened state from bottom to top, the heat exchanger tubes falling into the limiting groove are clamped sequentially, simplifying the operation. Furthermore, the clamping units within the end support support the heat exchanger tubes, ensuring that the ends of the tubes are centered on the holes in the tube sheet and limiting their movement during welding, thus preventing movement that could affect the welding result.

Description

Technical Field

[0001] This invention relates to the field of welding processing, and specifically to a welding apparatus and welding method for heat exchanger tubes. Background Technology

[0002] Shell-and-tube heat exchangers are core equipment in industries such as petrochemicals, nuclear power, and refrigeration, and their operational reliability is of paramount importance. The connection joint between the heat exchange tubes and the tube sheet is one of the weakest links in the heat exchanger. Its quality directly determines the equipment's pressure resistance, fatigue resistance, and corrosion resistance. Failure of this joint can lead to media mixing, causing serious production accidents and economic losses.

[0003] Traditional connection methods mainly include expansion joints, welding, and a combination of expansion and welding. Among these, welding is the preferred method for high-temperature and high-pressure conditions due to its excellent airtightness and high strength. Before welding, it is usually necessary to manually install the heat exchange tubes between two tube sheets and place them against the holes in the tube sheets, and adjust the relative position of the heat exchange tubes with the tube sheets in the axial direction to ensure the welding effect. Although this method is simple, manual placement has a large margin of error and is inefficient. Using the holes in the tube sheets to support the heat exchange tubes can easily lead to uneven welds, and the welding process is prone to shaking, affecting the weld quality. Summary of the Invention

[0004] This invention provides a welding device and method for welding heat exchanger tubes to solve the problem that large placement errors during heat exchanger tube welding affect welding quality in the prior art.

[0005] The heat exchanger tube welding device of the present invention adopts the following technical solution:

[0006] A heat exchanger tube welding device is provided for welding the two ends of multiple heat exchanger tubes to holes in two tube sheets. The device includes a mounting frame, end supports, and welding arms. The tube sheets are mounted on the mounting frame with their normal horizontal and are movable relative to the mounting frame along a first direction, which is the normal direction of the tube sheets. Two end supports are located between the two tube sheets and are distributed sequentially along the first direction. Each end support has a vertical limiting groove with its upper end penetrating the support, used to receive horizontally falling heat exchanger tubes. Multiple clamping units are spaced vertically within the limiting groove. Each clamping unit includes two first clamps and two second clamps, with the first clamps located below the second clamps, and both the first and second clamps being rotatably mounted on the end supports. The support structure, after rotation, forms a cylindrical structure with its axis along the first direction. The heat exchange tubes falling into the limiting groove do not extend beyond the two ends of the clamping units of the end supports, which are far apart from each other. The clamping units have a relaxed state and a tightened state. In the relaxed state, the heat exchange tubes can pass between the two second clamps and push the two first clamps to rotate before passing through the clamping units and continuing to fall. In the tightened state, the two first clamps rotate under the gravity of the falling heat exchange tubes and drive the two second clamps to move closer to each other, working together to clamp the heat exchange tubes. Multiple clamping units in the limiting groove switch from the relaxed state to the tightened state sequentially from bottom to top. The welding arm welds the installed heat exchange tubes to the tube sheet.

[0007] Optionally, both the first clamp and the second clamp are arc-shaped structures with their axes along the first direction, and one end of the arc-shaped structure is rotatably mounted on the end bracket around the axis of the first direction. A first transmission wheel is mounted on the rotating shaft of the first clamp, and a transmission sleeve is mounted on the rotating shaft of the second clamp. A telescopic transmission rod is slidably mounted inside the transmission sleeve along the first direction. The transmission rod rotates synchronously with the transmission sleeve. One end of the transmission rod extends out of the two end brackets, which are opposite to 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 mounted on the end bracket and are coaxially and fixedly connected. The second transmission wheel cooperates with the first transmission wheel for transmission, and the third transmission wheel is a tapered wheel used for transmission cooperation with the tapered portion. In the loose state, the third transmission wheel is disengaged from the tapered portion, and in the tight state, the tapered portion of the transmission rod cooperates with the third transmission wheel for transmission.

[0008] Optionally, a heat exchanger tube welding device further includes two top pressure plates, which are located on opposite sides of two end supports. Each top pressure plate is located between an end support and a tube sheet. The top pressure plates can be slidably mounted on the mounting frame along a first direction. A first elastic element is provided between the transmission rod and the transmission sleeve. The first elastic element causes the ends of the multiple transmission rods extending out of the end supports to be located on the same vertical plane in the initial state. A plurality of top pressure rods corresponding one-to-one with the clamping units are fixed on the side of the top pressure plate near the end supports. The first top pressure rod is used to abut against the transmission rod, and the length of the multiple top pressure rods decreases sequentially in the first direction from bottom to top.

[0009] Optionally, the transmission rod includes an outer tube, an inner rod, and a second elastic element. One end of the outer tube and the inner rod are slidably sleeved together along a first direction and connected by the second elastic element. The outer tube slides and rotates synchronously with the transmission sleeve. The inner rod is used to abut against the top pressure rod. The elastic force of the second elastic element is greater than that of the first elastic element.

[0010] Optionally, a heat exchanger tube welding device for a heat exchanger further includes an intermediate support, which is located between two end supports and fixed to the mounting bracket. The intermediate support has a slot corresponding to the limiting groove in a first direction, and the upper end of the slot communicates with the upper end surface of the intermediate support.

[0011] 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 support about an axis in a first direction. The multiple rollers are all arranged along the first direction and are distributed at intervals along an arc-shaped trajectory on the clamp frame. The axis of the arc-shaped trajectory is along the first direction. A linkage component is provided between the clamp frame and the intermediate support. When the end support and the intermediate support approach each other, the linkage component causes the multiple rollers to rotate to clean the outer peripheral wall of the heat exchange tube.

[0012] Optionally, the linkage assembly includes a linkage rod fixed on the intermediate support and a linkage pipe rotatably mounted on the clamp frame. The linkage pipe is screwed to the linkage rod, and the linkage pipe is connected to multiple rollers via a transmission belt.

[0013] Optionally, the outer peripheral wall of the roller is provided with a spiral groove to guide debris from the heat exchange tubes to fall off.

[0014] Optionally, there are multiple limiting grooves, which are arranged at intervals along the horizontal direction perpendicular to the heat exchange tube, and there are multiple corresponding slots.

[0015] A method for welding heat exchanger tubes, utilizing the aforementioned heat exchanger tube welding apparatus, includes the following steps:

[0016] S10, the heat exchange tube falls horizontally along the first direction to the limiting groove, and before each heat exchange tube falls, a clamping unit is switched to the clamping state from bottom to top;

[0017] S20, after all heat exchange tubes are installed, move the two end supports together synchronously so that the two ends of the heat exchange tubes extend out relative to the clamp unit and the end supports;

[0018] S30, Move the tube sheet so that the holes on the tube sheet correspond to the heat exchange tubes;

[0019] S40, the welding arm performs welding on the tube sheet and heat exchange tubes.

[0020] The beneficial effects of the present invention are: the heat exchange tube welding device of the present invention switches the clamping unit in the limiting groove from the bottom to the top from the loose state to the tight state, so that the heat exchange tubes falling into the limiting groove are clamped in sequence, without the need for manual locking one by one, and the operation is simple.

[0021] Furthermore, by installing clamp units within the end supports to support the heat exchange tubes, the ends of the heat exchange tubes can be positioned at the center of the holes in the tube sheet. Compared to the existing technology where the ends of the heat exchange tubes are placed inside the tube sheet holes before welding, the weld seam is more uniform and the welding quality is higher. The clamp units also limit the movement of the heat exchange tubes, preventing them from shifting during welding and affecting the welding effect.

[0022] Furthermore, as the two end supports approach each other, the position of the heat exchange tube in the first direction is adjusted by utilizing the different contact areas between the clamp unit and the heat exchange tube, so that the two ends of the heat exchange tube extend out of the two end supports by the same length, making the relative positions of the two ends with the two tube sheets consistent, thereby ensuring the welding consistency between the two tube sheets and the heat exchange tube.

[0023] Furthermore, when the heat exchange tube initially falls into the limiting groove and is clamped by the clamping unit, its end is located inside the cylindrical structure of the clamping unit. During the process of the end support moving to make the end of the heat exchange tube extend out of the end support, the first clamp and the second clamp generate friction cleaning on the end of the heat exchange tube to ensure the fit between the end of the heat exchange tube and the hole on the tube sheet. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a heat exchanger tube welding device according to the present invention;

[0026] Figure 2 This is a partial structural schematic diagram of an embodiment of a heat exchanger tube welding device according to the present invention;

[0027] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0028] Figure 4 for Figure 2 Side view;

[0029] Figure 5 for Figure 4 Enlarged view of point B in the middle;

[0030] Figure 6 This is a schematic diagram of the fit between the end support and the heat exchange tube in an embodiment of a heat exchanger tube welding device according to the present invention (only one clamp unit is shown in the figure).

[0031] Figure 7 for Figure 6 Enlarged view of point C in the middle;

[0032] Figure 8 for Figure 6 The front view (the clamp unit is in a clamped state in the figure);

[0033] Figure 9 for Figure 8 Schematic diagram of cross section in the DD direction;

[0034] Figure 10 for Figure 9 Enlarged view of point E in the middle;

[0035] Figure 11 This is a schematic diagram of the structure of the first clamp in an embodiment of a heat exchanger tube welding device of the present invention;

[0036] Figure 12 for Figure 8 Another schematic diagram of the state (the clamp unit in the figure is in a relaxed state);

[0037] Figure 13 for Figure 12 Enlarged schematic diagram at point F in the middle.

[0038] In the diagram: 100, mounting bracket; 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 element; 430, transmission rod; 431, outer tube; 432, inner rod; 433, second elastic element; 441, linkage rod; 442, linkage pipe; 500, tube sheet; 600, heat exchange tube; 700, top pressure plate; 710, top pressure rod; 800, welding arm. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] An embodiment of the heat exchanger tube welding device of the present invention is used to weld the two ends of a plurality of heat exchange tubes 600 to holes in two tube sheets 500, such as... Figures 1 to 13 As shown, it includes a mounting bracket 100 and an end bracket 200.

[0041] The tube sheet 500 is mounted on the mounting bracket 100, and the normal of the tube sheet 500 is horizontal. It can move relative to the mounting bracket 100 in a first direction, which is the normal direction of the tube sheet 500.

[0042] There are two end supports 200, located between two tube sheets 500 and distributed sequentially along the first direction. Each end support 200 has a vertically arranged limiting groove 210 that extends through the first direction. The upper end of each limiting groove 210 is connected to the upper end of the end support 200 to receive the horizontally falling heat exchange tube 600. Multiple clamping units 400 are arranged vertically at intervals within the limiting groove 210 of the end support 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 both the first and second clamps 420 are rotatably mounted on the end support 200. After rotation, the first clamps 410 and the second clamps 420 can form a cylindrical structure with their axis along the first direction. The ends of the heat exchange tube 600 falling into the limiting groove 210 do not extend beyond the mutually distant ends of the cylindrical structures of the clamping units 400 of the two end supports 200. The clamp unit 400 has a relaxed state and a tightened 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 before passing through the clamp unit 400 and continuing to fall. In the tightened state, the two first clamps 410 rotate under the gravity of the falling heat exchange tube 600 and drive the two second clamps 420 to move closer to each other, working together to clamp the heat exchange tube 600. The multiple clamp units 400 in the limiting groove 210 switch from the relaxed state to the tightened state from bottom to top.

[0043] Welding arm 800 welds the installed heat exchange tube 600 to the tube sheet 500.

[0044] The mounting frame 100 is mounted on a liftable mobile platform 110, which can move along a guide rail laid on the ground. The mobile platform 110 is a scissor lift mechanism commonly used in the prior art, and its movement is driven by a linear motor. By lifting and moving the mobile platform 110, the positions of the mounting frame 100 and the end brackets 200 mounted on it are adjusted, allowing the end brackets 200 on the mounting frame 100 to receive heat exchange tubes 600 falling from an external hopper (not shown in the figure). The heat exchange tubes 600 fall sequentially into the limiting groove 210 and are held tightly from bottom to top by the clamping units 400 within the limiting groove 210. Specifically, before the first heat exchange tube 600 falls, the lowest clamping unit 400 in the limiting groove 210 is tightened, while the other clamping units 400 are relaxed. The horizontally falling heat exchange tube 600 passes the relaxed clamping units 400 and pushes the first clamp 410 of the lowest clamping unit 400 to rotate, thereby causing the second clamp 420 to rotate and clamp the heat exchange tube 600. Before the second heat exchange tube 600 falls, the second clamping unit 400 from bottom to top is also switched to a tightened state, thus clamping the second heat exchange tube 600 that falls into the limiting groove 210. This process continues until each clamping unit 400 clamps one heat exchange tube 600. When the ends of the heat exchange tube 600 attached to the two end supports 200 do not extend beyond the cylindrical structure of the clamping unit 400, and there is a misalignment between the center of the heat exchange tube 600 and the distribution center of the clamping unit 400 of the two end supports 200, the contact length between the clamping unit 400 of the two end supports 200 and the heat exchange tube 600 in the first direction is different, and consequently, the contact area with the heat exchange tube 600 is different. When the two end supports 200 move closer to each other, causing the ends of the heat exchange tube 600 to extend beyond the two end supports 200 and move away from each other to one side, the clamping unit 400 of the end support 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 area between the clamping unit 400 of the two end supports 200 and the heat exchange tube 600 is the same. When the two end supports 200 continue to move closer to each other, the heat exchange tube 600 does not move axially. After the heat exchange tube 600 extends from both ends of the two end supports 200, the two tube sheets 500 are moved so that the holes of the tube sheet 500 correspond to the heat exchange tube 600, which facilitates subsequent welding.

[0045] By sequentially switching the clamping units 400 within the limiting groove 210 from a relaxed state to a tightened state from bottom to top, the heat exchange tubes 600 falling into the limiting groove 210 are clamped one by one, eliminating the need for manual locking of each tube individually, simplifying the operation. Furthermore, by providing clamping units 400 within the end bracket 200 to support the heat exchange tubes 600, the ends of the heat exchange tubes 600 are positioned at the center of the holes in the tube sheet 500. Compared to the prior art where the ends of the heat exchange tubes 600 are placed within the holes of the tube sheet 500 before welding, the weld seam is more uniform and the weld quality is higher. Moreover, the clamping units 400 can limit the movement of the heat exchange tubes 600 during welding, preventing them from shifting and affecting the welding effect. Furthermore, as the two end supports 200 approach each other, the different contact areas between the clamping unit 400 and the heat exchange tube 600 adjust the position of the heat exchange tube 600 in the first direction, ensuring that the two ends of the heat exchange tube 600 extend out of the two end supports 200 by the same length, and that the two ends are aligned with the relative positions of the two tube sheets 500, thereby ensuring the welding consistency 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 clamping unit 400, its end is located within the cylindrical structure of the clamping unit 400. During the movement of the end supports 200, causing the end of the heat exchange tube 600 to extend out of the end supports 200, the first clamp 410 and the second clamp 420 generate friction cleaning on the end of the heat exchange tube 600, ensuring the fit between the end of the heat exchange tube 600 and the holes on the tube sheet 500.

[0046] In this embodiment, both the first clamp 410 and the second clamp 420 are arc-shaped structures with their axes along a first direction, and one end of the arc-shaped structure is rotatably mounted on the end bracket 200 around the axis of the first direction. A third elastic element is provided between the first clamp 410 and the end bracket 200. The third elastic element causes the two first clamps 410 to be initially positioned on the descent 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 element is provided between the second clamp 420 and the end bracket 200. The fourth elastic element causes 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 elements are torsion springs. A transmission sleeve 421 is mounted on the rotating shaft of the second clamp 420. A telescopic transmission rod 430 is slidably mounted inside the transmission sleeve 421 along a first direction. The transmission rod 430 rotates synchronously with the transmission sleeve 421. One end of the transmission rod 430 extends out of the two end supports 200, which are opposite to each other, and one end of the extended end support 200 is provided with a tapered portion. Two sets of coaxial and fixedly connected second transmission wheels 220 and third transmission wheels 230 are rotatably mounted on the end supports 200. Each set corresponds to the transmission between a first clamp 410 and a second clamp 420. The second transmission wheel 220 cooperates with the first transmission wheel 411 for transmission. The third transmission wheel 230 is a tapered wheel used for transmission cooperation with the tapered portion. When the clamp unit 400 is in a relaxed state, the third transmission wheel 230 disengages from the tapered portion, and the rotation of the first clamp 410 is not transmitted to the second clamp 420, which remains in its initial position. When the clamping unit 400 is in the clamped state, the tapered portion of the transmission rod 430 engages with the third transmission wheel 230 for transmission. The rotation of the first clamp 410 is transmitted 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 tapered wheels and are also friction wheels or gears.

[0047] In this embodiment, a heat exchanger tube welding device further includes two top pressure plates 700. The two top pressure plates 700 are respectively located on opposite sides of the two end supports 200. Each top pressure plate 700 is located between an end support 200 and a tube sheet 500. The top pressure plate 700 can be slidably mounted on the mounting bracket 100 along a first direction. The top pressure plate 700 has a clearance groove reserved to allow the heat exchange tube 600 to pass through. A first elastic element 422 is provided between each transmission rod 430 and the transmission sleeve 421. The first elastic element 422 causes the ends of the multiple transmission rods 430 extending out of the end support 200 to be located on the same vertical plane in the initial state. On the side of the top pressure plate 700 near the end bracket 200, there are a plurality of top pressure rods 710 corresponding one-to-one with the clamp unit 400. The top pressure rods 710 are used to abut against the transmission rod 430. The length of the plurality of top pressure rods 710 decreases sequentially from bottom to top in the first direction. As the top pressure plate 700 approaches the end bracket 200, it pushes the top pressure rods 710 of the clamp unit 400 sequentially from bottom to top.

[0048] In this embodiment, the transmission rod 430 includes an outer tube 431, an inner rod 432, and a second elastic element 433. One end of the outer tube 431 and the inner rod 432 are slidably sleeved along a first direction and connected by the second elastic element 433. The outer tube 431 slides and rotates synchronously with the transmission sleeve 421. The inner rod 432 is used to abut against the top pressure rod 710. The elastic force of the second elastic element 433 is greater than that of the first elastic element 422. The transmission rod 430 is configured as a retractable elastic structure, so that after the lowermost top pressure rod 710 abuts against the transmission rod 430, the top pressure plate 700 can still continue to move closer to the end bracket 200 by compressing the transmission rod 430.

[0049] In this embodiment, a heat exchanger tube welding device further includes an intermediate support 300. The intermediate support 300 is located between two end supports 200 and fixed to the mounting bracket 100. The intermediate support 300 has a slot 310 corresponding to the limiting groove 210 in a first direction, and the upper end of the slot 310 communicates with the upper end surface of the intermediate support 300. The intermediate support 300 provides guidance and support for the middle part of the heat exchange tube 600.

[0050] 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 support 200 about an axis in a first direction. The plurality of rollers 412 are all arranged along the first direction and are distributed at intervals along an arc-shaped trajectory on the clamp frame 413. The axis of the arc-shaped trajectory is along the first direction. A linkage component is provided between the clamp frame 413 and the intermediate support 300. When the end support 200 and the intermediate support 300 approach each other, the linkage component causes the plurality of rollers 412 to rotate, cleaning the outer peripheral wall of the heat exchange tube 600.

[0051] In this embodiment, the linkage assembly includes a linkage rod 441 fixed to the intermediate support 300 and a linkage pipe 442 rotatably mounted on the clamp frame 413. The linkage pipe 442 is helically engaged with the linkage rod 441, and the linkage pipe 442 is connected to multiple rollers 412 via a transmission belt. When the end support 200 moves closer to the intermediate support 300, the linkage pipe 442 rotates under the helical engagement with the linkage rod 441, thereby driving the multiple rollers 412 to rotate via the transmission belt. This reduces the friction between the rollers 412 and the heat exchange tube 600 and also scrapes and cleans the outer surface of the heat exchange tube 600.

[0052] In this embodiment, a spiral groove is provided on the outer peripheral wall of the roller 412 to guide the debris on the heat exchange tube 600 to fall off.

[0053] In this embodiment, there are multiple limiting grooves 210, which are arranged sequentially at intervals along a horizontal direction perpendicular to the heat exchange tube 600, and there are multiple corresponding retaining grooves 310. Each limiting groove 210 corresponds to a row of holes on the tube sheet 500.

[0054] In this embodiment, the movement of the end brackets 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 lead screw and nut mechanism. To ensure that the two end brackets 200 can move synchronously towards the intermediate bracket 300, each end bracket 200 can be connected to a rack, and the two racks can mesh with the same gear located between them. Driving one end bracket 200 to move towards the intermediate bracket 300 will synchronously move the other end bracket 200 towards the intermediate bracket 300. The tube sheet 500 is typically a circular plate and requires two separate clamping plates to hold it. The movement of these clamping plates drives the synchronous movement of the tube sheet 500. The clamping plates are a common structure in the prior art and will not be described in detail.

[0055] Before use, the heat exchange tube welding device of the present invention adjusts the distance between the two end supports 200 according to the length of the heat exchange tube 600, and makes the two end supports 200, the two top pressure plates 700 and the two tube plates 500 symmetrically arranged about the distance of the intermediate support 300. By lifting and moving the mobile platform 110, the position of the mounting frame 100 and the end bracket 200 mounted on the mounting frame 100 is adjusted so that the end bracket 200 on the mounting frame 100 can receive the heat exchange tube 600 falling from the external hopper (not shown in the figure). The heat exchange tube 600 extends along the first direction and falls into the limiting groove 210 in sequence. Before the first heat exchange tube 600 falls, the top pressure plate 700 is moved to approach its corresponding end bracket 200. 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 part 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 loose clamp units 400 above, the first clamp 410 of each clamp unit 400 is pushed to rotate and continues to fall. When it lands on the two first clamps 410 of the lowest clamp unit 400, the two first clamps 410 are pushed to rotate. The first drive wheel 411 of the first clamp 410 rotates, driving the second drive wheel 220 and the third drive wheel 230 to rotate. The third drive wheel 230 drives the drive sleeve 421 to rotate, which in turn drives the two second clamps 420 to rotate, forming a cylindrical structure with the first clamps 410 to clamp the heat exchange tube 600. Before the next heat exchange tube 600 falls, the top pressure plate 700 is moved, so that the second clamp unit 400 from the bottom to the top also switches to the clamping state, thereby clamping the second heat exchange tube 600 that falls into the limiting groove 210. This process continues until each clamp unit 400 clamps one heat exchange tube 600.

[0056] Because the spacing between the two end supports 200 has been pre-adjusted, it can be ensured that neither end of the heat exchange tube 600 falling into the limiting groove 210 exceeds the ends of the cylindrical structure of the clamping unit 400 of the two end supports 200. After all the heat exchange tubes 600 are installed on the end supports 200, the two end supports 200 are moved closer to each other, and the two top pressure plates 700 move synchronously with their respective end supports 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 supports 200, the contact length between the clamping units 400 of the two end supports 200 and the heat exchange tube 600 in the first direction is different, resulting in different contact areas. When the two end supports 200 move closer together, causing the two ends of the heat exchange tube 600 to extend beyond the two end supports 200 and move away from each other to one side, the clamping unit 400 of the end support 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 between the clamping units 400 of the two end supports 200 and the heat exchange tube 600 are the same. When the two end supports 200 continue to move closer together, the heat exchange tube 600 does not move axially. Then, the two tube sheets 500 are moved closer together so that the holes of each tube sheet 500 correspond to one end of the heat exchange tube 600, and the welding arm 800 welds the tube sheet 500 and the heat exchange tube 600.

[0057] After welding, the top pressure plate 700 moves away from its corresponding end support 200, causing the transmission rod 430 to extend under the action of the first elastic element 422, thereby disengaging the conical part from the third transmission wheel 230. The second clamp 420 rotates under the action of the fourth elastic element, opening the two second clamps 420. The two first clamps 410 allow the heat exchange tube 600 to move up and down relative to the clamp unit 400 under the action of the third elastic element. When the end support 200 moves downward relative to the heat exchange tube 600, the heat exchange tube 600 pushes the two first clamps 410 above it to rotate upward and stretch the third elastic element, passing between the two first clamps 410. Specifically, the fastener of the tube sheet 500 can be removed from the mounting bracket 100. After the welded heat exchange tube 600 and tube sheet 500 are lifted, the lifting platform can be moved to drive the end support 200, the intermediate support 300 and the top pressure plate 700 to move downward synchronously and disengage from the heat exchange tube 600.

[0058] The present invention also proposes an embodiment of a heat exchanger tube welding method, which utilizes the aforementioned heat exchanger tube welding apparatus and includes the following steps:

[0059] S10, the heat exchange tube 600 falls horizontally along the first direction to the limiting groove 210, and before each heat exchange tube 600 falls, a clamping unit 400 is switched to the clamping state from bottom to top;

[0060] S20, after all heat exchange tubes 600 are installed, move the two end supports 200 together to bring them closer together, so that the two ends of the heat exchange tubes 600 extend out relative to the clamp unit 400 and the end supports 200.

[0061] S30, Move the tube sheet 500 so that the holes on the tube sheet 500 correspond to the heat exchange tubes 600;

[0062] S40, welding arm 800 welds tube sheet 500 and heat exchange tube 600.

[0063] 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 within the protection scope of the present invention.

Claims

1. A heat exchanger tube welding device for welding both ends of a plurality of heat exchanger tubes to holes in two tube sheets, characterized in that: Includes mounting bracket, end bracket, and welding arm; The tube sheet is mounted on the mounting bracket, and the normal of the tube sheet is horizontal. It can move relative to the mounting bracket along a first direction, which is the normal direction of the tube sheet. There are two end supports, located between the two tube sheets and distributed sequentially along the first direction. Each end support has a vertical limiting groove extending through the upper end to receive horizontally falling heat exchange tubes. Multiple clamping units are spaced vertically within the limiting groove. Each clamping unit includes two first clamps and two second clamps. The first clamps are located below the second clamps, and both the first and second clamps are rotatably mounted on the end support, forming a cylindrical structure with their axis along the first direction after rotation. The heat exchange tubes falling into the limiting groove do not exceed two clamps at either end. The cylindrical structure of the clamp unit of each end support is located at one end away from each other; 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 before passing through the clamp unit and continuing to fall; in the tightened state, the two first clamps rotate under the gravity of the falling heat exchange tube and drive the two second clamps to move closer to each other, working together with the two second clamps to clamp the heat exchange tube; the multiple clamp units in the limiting groove switch from the relaxed state to the tightened state from bottom to top. The welding arm welds the installed heat exchange tubes to the tube sheet.

2. The heat exchanger tube welding device according to claim 1, characterized in that: Both the first and second clamps are arc-shaped structures with their axes along a first direction. One end of the arc-shaped structure is rotatably mounted on an end bracket around the axis of the first direction. A first transmission wheel is mounted on the shaft of the first clamp, and a transmission sleeve is mounted on the shaft of the second clamp. A telescopic transmission rod is slidably mounted inside the transmission sleeve along the first direction. The transmission rod rotates synchronously with the transmission sleeve. One end of the transmission rod extends out of the two end brackets, which are opposite to each other, and one end of the extended end bracket is provided with a tapered portion. A second and third transmission wheel, which are coaxial and fixedly connected, are rotatably mounted on the end brackets. The second transmission wheel cooperates with the first transmission wheel for transmission, and the third transmission wheel is a tapered wheel used for transmission cooperation with the tapered portion. In the relaxed state, the third transmission wheel is disengaged from the tapered portion. In the clamped state, the tapered portion of the transmission rod cooperates with the third transmission wheel for transmission.

3. The heat exchanger tube welding device according to claim 2, characterized in that: It also includes two top pressure plates, which are located on opposite sides of the two end supports. Each top pressure plate is located between an end support and a tube sheet. The top pressure plates can be slidably mounted on the mounting frame in the first direction. A first elastic element is provided between the transmission rod and the transmission sleeve. The first elastic element causes the ends of the multiple transmission rods extending out of the end supports to be located on the same vertical plane in the initial state. Multiple top pressure rods corresponding to the clamping units are fixed on the side of the top pressure plate near the end supports. The first top pressure rod is used to abut against the transmission rod, and the length of the multiple top pressure rods decreases sequentially in the first direction from bottom to top.

4. The heat exchanger tube welding device according to claim 3, characterized in that: The transmission rod includes an outer tube, an inner rod, and a second elastic element. One end of the outer tube and the inner rod are slidably sleeved together along a first direction and connected by the second elastic element. The outer tube slides and rotates synchronously with the transmission sleeve. The inner rod is used to abut against the top pressure rod. The elastic force of the second elastic element is greater than that of the first elastic element.

5. The heat exchanger tube welding device 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 has a slot that corresponds to the limiting slot in the first direction, and the upper end of the slot is connected to the upper end face of the intermediate bracket.

6. The heat exchanger tube welding device 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 an end support about an axis in a first direction. The multiple rollers are all arranged along the first direction and are distributed at intervals along an arc-shaped trajectory on the clamp frame. The axis of the arc-shaped trajectory is along the first direction. A linkage component is provided between the clamp frame and the intermediate support. When the end support and the intermediate support approach each other, the linkage component causes the multiple rollers to rotate, cleaning the outer peripheral wall of the heat exchange tube.

7. The heat exchanger tube welding device according to claim 6, characterized in that: The linkage assembly includes a linkage rod fixed on the intermediate support and a linkage pipe rotatably mounted on the clamp frame. The linkage pipe is screwed to the linkage rod, and the linkage pipe is connected to multiple rollers for transmission via a transmission belt.

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

9. The heat exchanger tube welding device according to claim 5, characterized in that: There are multiple limiting grooves, which are arranged at intervals along the horizontal direction perpendicular to the heat exchange tube, and there are multiple corresponding slots.

10. A method for welding heat exchanger tubes, using a heat exchanger tube welding apparatus according to any one of claims 1 to 9, characterized in that, Includes the following steps: S10, the heat exchange tube falls horizontally along the first direction to the limiting groove, and before each heat exchange tube falls, a clamping unit is switched to the clamping state from bottom to top; S20, after all heat exchange tubes are installed, move the two end supports together synchronously so that the two ends of the heat exchange tubes extend out relative to the clamp unit and the end supports; S30, Move the tube sheet so that the holes on the tube sheet correspond to the heat exchange tubes; S40, the welding arm performs welding on the tube sheet and heat exchange tubes.

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