A fully welded plate heat exchanger core based on S-shaped weld and welding method thereof

Abstract

The present application discloses a fully welded plate heat exchanger core based on S-shaped welds and a welding method thereof, wherein a plurality of heat exchange plates of the core are sequentially connected from top to bottom to form a plate bundle, and continuous S-shaped welding edges are formed at the four corners of the plate bundle from top to bottom; column linings are arranged at the four corners of the plate bundle, and continuous S-shaped slots are arranged at the bending parts of the column linings from top to bottom, and the S-shaped welding edges are inserted into the S-shaped slots, and the S-shaped welding edges and the column linings are connected by welding; the upper and lower ends of the plate bundle are respectively provided with a top plate and a bottom plate, and the four corners of the top plate and the bottom plate are connected to the column linings; four baffle frames are respectively provided around the plate bundle, and the upper and lower ends of the baffle frames are respectively connected to the top plate and the bottom plate, and the left and right ends of the baffle frames are respectively connected to the column linings on both sides thereof. The present application solves the problems of high processing difficulty and low welding efficiency when improving the welding structure of the plate bundle and the column lining in the prior art.

Description

Technical Field

[0001] The present application belongs to the field of welding technology, and specifically relates to a fully welded plate heat exchanger core based on an S-shaped weld and a welding method thereof. Background Art

[0002] As a compact, efficient and high-end heat exchange equipment, the fully welded plate heat exchanger core is widely used in petrochemical, food, medicine, electricity and other fields. The fully welded plate heat exchanger core is mainly connected by the core, columns, cover plates, clamping plates, pipes, seals and flanges. Among them, the core is the main location for heat exchange and fluid pressure, and is the key component of the fully welded plate heat exchanger core. The core is mainly composed of plate bundles, column linings and connecting plates, and all parts are connected by welding. For the needs of pressure resistance and fatigue resistance, welding structures connected to the column linings are set at the four top corners of the plate bundle.

[0003] In the traditional welding structure of plate bundles and column linings, cross welds are inevitable. Since the welds are usually coarse-grained cast structures accompanied by residual welding stress, when the welds are cross-distributed, it not only increases the welding stress, but also increases the risk of metal overheating and defect formation, resulting in reduced compressive strength at the connection points between the four top corners of the plate bundle and the column lining, which in turn becomes a weak link in the heat exchanger core. Improving the welding structure is a common way to solve the above problems, such as changing the shape of the heat exchanger plates or the structure of the column lining. Although the above improvement methods effectively avoid cross welds and the risks induced by them, these two common improvement methods are not only difficult to process, have low welding efficiency, and limited connection area, but also increase the requirements for heat exchanger manufacturing equipment and increase the manufacturing cost of the fully welded plate heat exchanger core. Summary of the invention

[0004] The embodiment of the present application solves the problems of great processing difficulty and low welding efficiency in the prior art when improving the welding structure of the plate bundle and the column liner by providing a fully welded plate heat exchanger core based on an S-shaped weld and a welding method thereof.

[0005] In order to achieve the above-mentioned object, an embodiment of the present invention provides a fully welded plate heat exchanger core based on an S-shaped weld, including a heat exchange plate, a column liner, a top plate, a bottom plate and a baffle frame;

[0006] The plurality of heat exchange plates are sequentially connected from top to bottom to form a plate bundle, and four corners of the plate bundle form continuous S-shaped welding edges from top to bottom;

[0007] The column lining plates are arranged at the four corners of the plate bundle, a continuous S-shaped insertion seam is arranged at the bending part of the column lining plate from top to bottom, the S-shaped welding edge is inserted into the S-shaped insertion seam, and the S-shaped welding edge and the column lining plate are connected by welding;

[0008] The top plate and the bottom plate are respectively disposed at the upper end and the lower end of the plate bundle, and the four corners of the top plate and the bottom plate are connected to the column lining plate;

[0009] Four baffle frames are respectively arranged around the plate bundle, the upper and lower ends of the baffle frames are respectively connected to the top plate and the bottom plate, and the left and right ends of the baffle frames are respectively connected to the column linings on both sides thereof.

[0010] In a possible implementation, the heat exchange plate includes a center plate and four folded edges;

[0011] The central plate is a rectangular plate body, the four corners of the central plate are provided with triangular cutouts, and the four sides of the central plate are respectively provided with four folded edges;

[0012] The two ends of the folded edge extend to the triangular incisions on both sides thereof, and the bending directions of the two adjacent folded edges are opposite; the edge of the triangular incision and the edges of the two adjacent folded edges form a welding edge, and the welding edges of the multiple heat exchange plates are sequentially connected to form the continuous S-shaped welding edge.

[0013] In a possible implementation, the column lining plate includes a first vertical plate, a docking plate, and a second vertical plate connected in sequence from left to right;

[0014] A vertical plate smooth transition section is provided between the butt joint plate and the first vertical plate and the second vertical plate;

[0015] A heat exchange plate smooth transition section is provided between the folded edge and the center plate;

[0016] The edge of the triangular incision is inserted into the portion of the S-shaped slot located on the docking plate, the edge of the smooth transition section of the heat exchange plate is inserted into the portion of the S-shaped slot located on the smooth transition section of the vertical plate, and the edge of the folded edge is inserted into the portion of the S-shaped slot located on the first vertical plate or the second vertical plate.

[0017] In a possible implementation, a group of support components and a group of baffle system components are respectively provided in the middle of the two opposite baffle frames, and the two ends of the support components or the two ends of the baffle system components are respectively connected to the middle of the left and right sides of the corresponding baffle frames.

[0018] In a possible implementation, the baffle frame includes four baffle members connected in sequence, the four baffle members are detachably connected, and the baffle members are connected to the top plate, the bottom plate or the column lining through a bolt assembly.

[0019] In one possible implementation, the support assembly includes a support rod and a connecting member, one end of the support rod is connected to one side of the baffle frame, the other end of the support rod is threadedly connected to one end of the connecting member, and the other end of the connecting member is connected to the other side of the baffle frame.

[0020] In a possible implementation, the baffle system assembly includes a baffle plate and a clamping member; the baffle plate is vertically provided with clamping edges on both sides thereof;

[0021] Two of the clamping parts are respectively arranged on the left and right sides of the baffle frame, and the two clamping parts are arranged opposite to each other. The opposite ends of the two clamping parts are both provided with warping edges, and a mounting groove is formed between the warping edges and the baffle frame;

[0022] The two baffles are fixed as a whole in a vertically symmetrical manner and then inserted into the mounting groove through the clamping edge and fixed.

[0023] In a possible implementation, a head plate is provided between the upper end of the plate bundle and the top plate, the head plate has the same structure as the heat exchange plate, the height of the corrugated groove on the head plate is consistent with the height of the folded edge at the upper portion of the head plate, the corrugated groove on the head plate abuts against the bottom surface of the top plate, and the edge of the folded edge at the upper portion of the head plate is welded to the bottom surface of the top plate;

[0024] A tail plate is arranged between the lower end of the plate bundle and the bottom plate, folded edges are arranged on the upper parts of both sides of the tail plate, the bottom surface of the tail plate abuts against the top surface of the bottom plate, and the four sides of the tail plate are circumferentially welded to the top surface of the bottom plate.

[0025] In order to achieve the above object, an embodiment of the present invention further provides a welding method for a fully welded plate heat exchanger core based on an S-shaped weld, comprising the following steps:

[0026] The heat exchange plates are stacked so that the gap between the folded edges of two adjacent heat exchange plates is less than 0.2 mm, and then the folded edges of two adjacent heat exchange plates are welded until the plate bundle is completed;

[0027] Insert the S-shaped welding edge of the plate bundle into the S-shaped insertion seam on the corresponding column lining plate, extend the S-shaped welding edge to the outside of the S-shaped insertion seam, and then weld the S-shaped welding edge and the column lining plate outside the column lining plate.

[0028] In a possible implementation, the following steps are also included:

[0029] A left lining plate and a right lining plate are cut out of the plate, and a plurality of slots are arranged in the middle of the left lining plate and the right lining plate, and a plug plate is formed between the plurality of slots; and then the left lining plate and the right lining plate are bent into shape;

[0030] Insert the plug-in plate of the left liner and the plug-in plate of the right liner into the S-shaped welding edge of the plate bundle, and butt the left liner and the right liner at the slot and the plug-in plate to form the S-shaped insertion seam;

[0031] The upper part and the lower part of the left lining plate are respectively welded to the upper part and the lower part of the right lining plate, and the left lining plate and the right lining plate are connected to form the column lining plate.

[0032] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0033] The embodiment of the present invention provides a fully welded plate heat exchanger core and a welding method thereof. The present invention sets four independent column linings, and pre-processes an S-shaped slot on each column lining. At the same time, the four corners of the heat exchange plate are cut so that the S-shaped welding edge of the plate bundle forms a shape that matches the size and shape of the S-shaped slot, and then welds after assembly. This method reduces the difficulty of welding the plate bundle and the column lining, and avoids the appearance of a cross weld. When welding, a melting welding method is used, so there is more room for plate selection and a wider range of applications, thereby improving manufacturing efficiency, ensuring heat exchange performance, and enhancing the reliability of the core. Compared with the comb-tooth weld formed by traditional dense splicing, the S-shaped slot of the present invention has high strength after welding with the plate bundle, greatly reducing the stress concentration acting on the column lining, making the weld S-shaped and smoothly transitioning. During the weld forming process, the continuous slow cooling time of the weld of the present invention is longer, which has the effect of annealing the rear weld, making its mechanical properties better than other cross-type and comb-tooth weld structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 A schematic structural diagram of a fully welded plate heat exchanger core based on an S-shaped weld provided in an embodiment of the present invention.

[0036] Figure 2 A schematic diagram of the plug-in state of the plate bundle and the column liner provided in an embodiment of the present invention.

[0037] Figure 3 for Figure 2 Enlarged view of point A.

[0038] Figure 4 A schematic diagram comparing the column lining plate and the S-shaped welding edge before and after welding provided in an embodiment of the present invention.

[0039] Figure 5 A schematic diagram of the structure of a plate bundle provided in an embodiment of the present invention.

[0040] Figure 6 A schematic diagram of the structure of a heat exchange plate provided in an embodiment of the present invention.

[0041] Figure 7 A schematic diagram of the structure of the three-layer heat exchange plate after welding provided in an embodiment of the present invention.

[0042] Figure 8 A schematic diagram of the structure of the tail plate and the bottom plate after welding provided by an embodiment of the present invention.

[0043] Fig. 9 A schematic structural diagram of a column liner provided in Example 1 of the present invention.

[0044] Fig.10 A schematic diagram of the structure of a column liner provided in Embodiment 2 of the present invention.

[0045] Fig.11 A schematic diagram of the arrangement of the baffle frame, support assembly and baffle system assembly provided in an embodiment of the present invention.

[0046] Fig.12 A schematic diagram of the structure of a baffle provided in an embodiment of the present invention.

[0047] Fig.13 A schematic diagram of the assembly of a fully welded plate heat exchanger core based on an S-shaped weld provided in an embodiment of the present invention.

[0048] Figure numerals: 1-heat exchange plate; 11-center plate; 12-folded edge; 13-triangular incision; 14-smooth transition section of heat exchange plate; 2-column lining plate; 21-S-shaped slot; 22-first vertical plate; 23-butt plate; 24-second vertical plate; 25-smooth transition section of vertical plate; 26-left lining plate; 27-right lining plate; 28-slot; 29-insertion plate; 3-top plate; 4-bottom plate; 5-baffle frame; 51-baffle member; 6-S-shaped welding edge; 7-support assembly; 71-support rod; 72-connector; 8-baffle system assembly; 81-baffle; 811-clip edge; 82-clip; 821-warped edge; 9-head plate; 10-corrugated groove; 20-tail plate; 30-rectangular incision. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] In the description of the embodiments of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the present invention. The terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances.

[0051] like Figures 1 to 13 As shown, the fully welded plate heat exchanger core based on the S-shaped weld provided in the embodiment of the present invention includes a heat exchange plate 1, a column lining plate 2, a top plate 3, a bottom plate 4 and a baffle frame 5.

[0052] A plurality of heat exchange plates 1 are sequentially connected from top to bottom to form a plate bundle, and continuous S-shaped welding edges 6 are formed at the four corners of the plate bundle from top to bottom.

[0053] Column lining plates 2 are arranged at the four corners of the plate bundle, and a continuous S-shaped slot 21 is arranged at the bending part of the column lining plate 2 from top to bottom. The S-shaped welding edge 6 is inserted into the S-shaped slot 21, and the S-shaped welding edge 6 and the column lining plate 2 are connected by welding.

[0054] The upper end and the lower end of the plate bundle are respectively provided with a top plate 3 and a bottom plate 4 , and the four corners of the top plate 3 and the bottom plate 4 are connected to the column lining plate 2 .

[0055] Four baffle frames 5 are arranged around the plate bundle, and the upper and lower ends of the baffle frames 5 are connected to the top plate 3 and the bottom plate 4 respectively, and the left and right ends of the baffle frames 5 are connected to the column lining plates 2 on both sides thereof respectively.

[0056] It should be noted that the corrugated grooves 10 on all the heat exchange plates 1 are oriented in the same direction. The number of heat exchange plates 1 is 2 to 500. The length of the heat exchange plate 1 is 150 to 1200 mm, the width is 150 to 1200 mm, and the thickness is 0.6 to 1.5 mm. The thickness of the column lining 2 is 1.0 to 5.0 mm. The structure of the top plate 3 is the same as that of the bottom plate 4. The length of the top plate 3 is 150 to 1200 mm, the width is 150 to 1200 mm, and the thickness is 1 to 5 mm. Rectangular cutouts 30 are provided at the four corners of the top plate 3 and the bottom plate 4, and the rectangular cutouts 30 match the column lining 2. The baffle frame 5 connects the column lining 2, the top plate 3 and the bottom plate 4 as a whole to improve the overall strength. The S-shaped slot 21 is a continuous regular curved cut, which, like other sheet metal parts with curved shapes that are processed by cutting and bending, will not cause additional damage to the strength of the parent material. The other structures and operating principles of the heat exchanger core are prior art, so they are not further described in this embodiment.

[0057] The present invention sets four independent column lining plates 2, and pre-processes an S-shaped slot 21 on each column lining plate 2. At the same time, the four corners of the heat exchange plate 1 are cut so that the S-shaped welding edge 6 of the plate bundle forms a shape that matches the size and shape of the S-shaped slot 21, and then welds after assembly. This method reduces the difficulty of welding the plate bundle and the column lining plate 2, and avoids the appearance of a cross weld. When welding, a melting welding method is adopted, so there is a greater choice of plates and a wider range of applications, thereby improving manufacturing efficiency, ensuring heat exchange performance, and enhancing the reliability of the core. Compared with the comb-tooth weld formed by traditional dense splicing, the S-shaped slot 21 of the present invention has high strength after welding with the plate bundle, greatly reducing the stress concentration acting on the column lining plate 2, making the weld S-shaped and smoothly transitioning. During the weld forming process, the continuous slow cooling time of the weld of the present invention is longer, which has the effect of annealing the rear weld, making its mechanical properties better than other cross-type and comb-tooth weld structures.

[0058] In this embodiment, the heat exchange plate 1 includes a center plate 11 and four folded edges 12 .

[0059] The center plate 11 is a rectangular plate body, and triangular cutouts 13 are arranged at the four corners of the center plate 11 . Four folded edges 12 are arranged at the four sides of the center plate 11 .

[0060] The two ends of the folded edge 12 extend to the triangular cutouts 13 on both sides thereof, and the bending directions of the two adjacent folded edges 12 are opposite. The edge of the triangular cutout 13 and the edges of the two adjacent folded edges 12 form a welding edge, and the welding edges of the multiple heat exchange plates 1 are sequentially connected to form a continuous S-shaped welding edge 6.

[0061] It should be noted that the triangular cutout 13 is a structure formed by cutting off a triangle from the right angle portion of the center plate 11, and the triangle is an isosceles right triangle. When the heat exchange plate 1 is manufactured, the plate is first cut and then bent to form, so the processing technology is simple and the strength is high.

[0062] like Fig. 9 As shown, in the first embodiment, the column lining plate 2 includes a first vertical plate 22, a docking plate 23 and a second vertical plate 24 which are sequentially connected from left to right.

[0063] A vertical plate smooth transition section 25 is provided between the butt joint plate 23 and the first vertical plate 22 and the second vertical plate 24. The S-shaped slot 21 is provided on the first vertical plate 22, the butt joint plate 23, the second vertical plate 24 and the vertical plate smooth transition section 25.

[0064] A heat exchange plate smooth transition section 14 is provided between the folded edge 12 and the center plate 11 .

[0065] The edge of the triangular cutout 13 is inserted into the portion of the S-shaped slot 21 located on the docking plate 23, the edge of the heat exchange plate smooth transition section 14 is inserted into the portion of the S-shaped slot 21 located on the vertical plate smooth transition section 25, and the edge of the folded edge 12 is inserted into the portion of the S-shaped slot 21 located on the first vertical plate 22 or the second vertical plate 24.

[0066] It should be noted that the first vertical plate 22 and the second vertical plate 24 are perpendicular to each other, and the ends of the first vertical plate 22 and the second vertical plate 24 are both provided with a bent portion. When the column lining plate 2 in this embodiment is manufactured, the plate is first cut into a set shape, then an S-shaped insertion seam 21 is cut, and then the plate is bent to form, so the processing technology is simple and the strength is high.

[0067] In actual processing, the bending parts of the column lining plate 2 and the heat exchange plate 1 need to be smoothly transitioned. The connection structure is the smooth transition section 25 of the column and the smooth transition section 14 of the heat exchange plate. In this embodiment, by refining the specific connection parts of the S-shaped insertion seam 21 and the S-shaped welding edge 6, the core body processing can have higher operability and meet higher processing accuracy.

[0068] In this embodiment, a group of support components 7 and a group of baffle system components 8 are respectively provided in the middle of the two opposite baffle frames 5, and the two ends of the support components 7 or the two ends of the baffle system components 8 are respectively connected to the middle of the left and right sides of the corresponding baffle frames 5.

[0069] It should be noted that if Fig.13As shown, the plate bundle channels located on the upper and lower sides of the baffle system assembly 8 are the inlet and outlet of the heat source or the inlet and outlet of the cold source respectively. The baffle frame 5 is provided with an air guide plate on one side of the support assembly 7. The space between the air guide plate and the plate bundle connects the upper and lower parts of the plate bundle, so that the outlet and inlet of the heat exchanger can be set on the same side of the plate bundle, thereby meeting different usage requirements.

[0070] In this embodiment, the baffle frame 5 includes four baffle members 51 connected in sequence, the four baffle members 51 are detachably connected, and the baffle members 51 are connected to the top plate 3, the bottom plate 4 or the column lining 2 through a bolt assembly.

[0071] It should be noted that the four baffle members 51 in this embodiment are two long and two short structures, the longer baffle member 51 is 300-4000 mm long and 40-200 mm wide, and the shorter baffle member 51 is 200-1500 mm long and 40-200 mm wide. The thickness of the baffle member 51 is 3.0-10.0 mm. The four baffle members 51 are connected by a bolt assembly, and the four baffle members 51 are easy to adjust and disassemble. The bolt assembly includes at least a nut and a bolt.

[0072] In this embodiment, the support assembly 7 includes a support rod 71 and a connecting member 72, one end of the support rod 71 is connected to one side of the baffle frame 5, the other end of the support rod 71 is threadedly connected to one end of the connecting member 72, and the other end of the connecting member 72 is connected to the other side of the baffle frame 5.

[0073] It should be noted that the support rod 71 and the connecting member 72 are threadedly connected, so it is easy to adjust the length. The support rod 71 is formed by combining solid rods or hollow tubes of different diameters. The size of the support rod 71 is 200 to 1500 mm in length and 5 to 25 mm in diameter.

[0074] In this embodiment, the baffle system assembly 8 includes a baffle plate 81 and a clamping member 82. The baffle plate 81 is vertically provided with clamping edges 811 on both sides thereof.

[0075] Two clamping parts 82 are respectively provided on the left and right sides of the baffle frame 5. The two clamping parts 82 are arranged opposite to each other. The opposite ends of the two clamping parts 82 are provided with warped edges 821, and a mounting groove is formed between the warped edges 821 and the baffle frame 5.

[0076] The two baffles 81 are fixed together in a vertically symmetrical manner and then fixed by inserting the clamping edge 811 into the installation groove.

[0077] It should be noted that the support assembly 7 and the baffle system assembly 8 are used to provide flow distribution of the medium in the core and improve the pressure bearing capacity of the core.

[0078] A reinforcing rib is provided at the center of the baffle 81, and a flange is provided at the front side of the baffle 81, which is located on the side of the baffle 81 away from the plate bundle. The dimensions of the baffle 81 are 150 to 1200 mm on the long side, 35 to 200 mm on the short side, and 0.8 to 5 mm in thickness. The two baffles 81 are welded and connected, and the two baffles 81 are installed by plugging, so they are easy to disassemble and assemble.

[0079] In this embodiment, a head plate 9 is arranged between the upper end of the plate bundle and the top plate 3. The structure of the head plate 9 is the same as that of the heat exchange plate 1. The height of the corrugated groove 10 on the head plate 9 is consistent with the height of the folded edge 12 on the upper part of the head plate 9. The corrugated groove 10 on the head plate 9 abuts against the bottom surface of the top plate 3, and the edge of the folded edge 12 on the upper part of the head plate 9 is welded to the bottom surface of the top plate 3.

[0080] A tail plate 20 is arranged between the lower end of the plate bundle and the bottom plate 4, and folded edges 12 are arranged on the upper parts of both sides of the tail plate 20. The bottom surface of the tail plate 20 abuts against the top surface of the bottom plate 4, and the four sides of the tail plate 20 are circumferentially welded to the top surface of the bottom plate 4.

[0081] It should be noted that no folding edge 12 is provided at the lower portion of the tail plate 20 , and the folding edge 12 on the tail plate 20 and the folding edge 12 on the head plate 9 are welded using the same welding process as the folding edge 12 of the heat exchange plate 1 .

[0082] The length of the head plate 9 is 150-1200 mm, the width is 150-1200 mm, and the thickness is 0.6-1.5 mm. The length of the tail plate 20 is 150-1200 mm, the width is 150-1200 mm, and the thickness is 0.6-1.5 mm. The head plate 9 and the tail plate 20 are provided to improve the sealing of the connection between the plate bundle and the top plate 3 and the bottom plate 4, while ensuring the pressure bearing capacity of the core.

[0083] like Figures 1 to 13 As shown, the welding method of a fully welded plate heat exchanger core based on an S-shaped weld provided in an embodiment of the present invention comprises the following steps:

[0084] The heat exchange plates 1 are stacked so that the gap between the folded edges 12 of two adjacent heat exchange plates 1 is less than 0.2 mm, and then the folded edges 12 of two adjacent heat exchange plates 1 are welded until the plate bundle is completed.

[0085] Insert the S-shaped welding edge 6 of the plate bundle into the S-shaped insertion slot 21 on its corresponding column lining plate 2, so that the S-shaped welding edge 6 extends 0 to 2 mm outside the S-shaped insertion slot 21, and then weld the S-shaped welding edge 6 and the column lining plate 2 outside the column lining plate 2.

[0086] It should be noted that the heat exchange plates 1 and the head plates 9 and the tail plates 20 are stacked using special tooling. The head plates 9 and the tail plates 20 are also part of the plate bundle. A fluid channel is formed between two adjacent heat exchange plates 1, and the adjacent fluid channels are cross-distributed. The stacked heat exchange plates 1 are welded into a plate bundle using a melting welding method. When welding the heat exchange plates 1 to form a plate bundle, a laser welding method without filling wire is selected, and atmosphere protection is applied to the front and back of the weld respectively, wherein the power of the laser welding is 600-850W, the welding speed is 0.01-0.02m / s, the defocus is -5-5mm, the front protective gas of the weld is not less than 99.99% argon or nitrogen, the flow rate is 10-20L / min, and the back protective gas of the weld is not less than 99.99% argon or nitrogen, the flow rate is 2-10L / min.

[0087] When the S-shaped welding edge 6 of the plate bundle is welded to the column lining plate 2, a tungsten inert gas arc welding method with or without wire filling is selected, wherein the welding current is 30-60A, the welding voltage is 3.5-8V, the welding speed is 0.05-0.2m / min, the front shielding gas of the weld is not less than 99.99% argon or nitrogen, with a flow rate of 10-25L / min, and the back shielding gas of the weld is not less than 99.99% argon or nitrogen, with a flow rate of 5-15L / min. When filling wire, the diameter of the welding wire is 0.8-1.2mm, and the wire feeding speed is 1.0-3.0mm / s.

[0088] The state before welding of the S-shaped welding edge 6 and the S-shaped insertion seam 21 is as follows: Figure 4 As shown in the upper part, when the S-shaped welding edge 6 and the S-shaped insertion seam 21 are welded, the high temperature generated by welding melts the top excess height of the S-shaped welding edge 6, and further melts the adjacent edges of the S-shaped welding edge 6 and the S-shaped insertion seam 21. By swinging the welding gun, the molten material fills the S-shaped insertion seam 21, so that an S-shaped weld is formed between the S-shaped welding edge 6 and the column lining plate 2. If necessary, welding wire is added to ensure that both the front and back sides of the column lining plate 2 are formed. The cross section of the S-shaped weld is as shown in FIG. Figure 4 Shown as the black block in the lower middle part.

[0089] Then, the plate bundle is welded together with the top plate 3 and the bottom plate 4 in the form of fillet welds by using a melting welding method with or without wire filling. When welding the top plate 3, the bottom plate 4 and the plate bundle, a tungsten inert gas arc welding method with wire filling is selected, wherein the welding current is 30-60A, the welding voltage is 3.5-8V, the welding speed is 0.05-0.2m / min, the front shielding gas of the weld is argon or nitrogen of not less than 99.99%, the flow rate is 10-25L / min, the back shielding gas of the weld is argon or nitrogen of not less than 99.99%, the flow rate is 5-15L / min, when the wire is filled, the diameter of the welding wire is selected to be 0.8-1.2mm, and the wire feeding speed is 1.0-3.0mm / s.

[0090] In this embodiment, welding methods such as laser welding, micro-beam plasma welding and argon arc welding can be used.

[0091] The plate bundle of the present invention needs to be welded twice. The welding structure is a continuous S-shaped weld, so no cross welds and sharp-angle welds are formed, which prevents multiple welding and heating at the plate corners, effectively reduces stress concentration and welding residual stress, and can achieve the purpose of higher weld quality, smaller heat-affected zone, and higher welding efficiency, which can greatly improve the product quality, reliability and service life.

[0092] The heat exchange plate 1 of the present invention is completed by a trimming die, and the accuracy can reach ±0.08mm. The S-shaped slot 21 of the column liner 2 is completed by precision laser cutting, and the accuracy can reach ±0.05mm. The assembly gap between the heat exchange plate 1 and the column liner 2 is 0.3mm. On the one hand, this assembly gap can ensure the simple assembly between the plate bundle and the column liner 2, and on the other hand, it can meet the requirements of the S-shaped weld of the column liner 2. The melting welding method with or without filling wire can be used. In addition, the S-shaped structure welding between the plate angle structure and the column liner 2 adopts equal strength matching to ensure that the strength of the weld is equivalent to the strength of the parent material.

[0093] In the second embodiment, the following steps are also included:

[0094] A left lining plate 26 and a right lining plate 27 are cut out of the plate, and a plurality of slots 28 are arranged in the middle of the left lining plate 26 and the right lining plate 27, and a plug plate 29 is formed between the plurality of slots 28. Then the left lining plate 26 and the right lining plate 27 are bent and formed.

[0095] The inserting plate 29 of the left lining plate 26 and the inserting plate 29 of the right lining plate 27 are plugged into the S-shaped welding edge 6 of the plate bundle, and the left lining plate 26 and the right lining plate 27 are butted at the slot 28 and the inserting plate 29 to form an S-shaped insertion seam 21.

[0096] The upper and lower parts of the left lining plate 26 are welded to the upper and lower parts of the right lining plate 27 respectively, and the left lining plate 26 and the right lining plate 27 are connected to form the column lining plate 2.

[0097] It should be noted that if Fig.10 As shown, the column liner 2 in this embodiment includes a left liner 26 and a right liner 27, the left liner 26 and the right liner 27 are butted at the slot 28 and the plug 29 to form an S-shaped insertion seam 21, and the upper and lower parts of the left liner 26 and the right liner 27 are connected by welding. The present invention uses the left liner 26 and the right liner 27 to splice to obtain the column liner 2, and such a column liner 2 can be easily plugged and connected with the plate bundle, thereby improving processing efficiency.

[0098] There are two types of welding structures between the top corners of the core plate bundle and the column liner 2 of the traditional fully welded plate heat exchanger based on S-shaped welds. One is the plate end connection with the plate corner comb plate structure. The plate bundle core needs to be welded twice, that is, the plate end connection once and the column liner 2 is welded once. There are clean dead zones at the plate end connection position and the plate corner position of this structure, which is very easy to cause blockage and corrosion leakage. The other is the plate end connection with the plate corner small wing structure. The plate bundle core needs to be welded three to five times. The mature foreign technology requires three weldings, that is, the plate is butted once and the column liner 2 is welded twice. Five weldings are required in China, that is, the plate is butted once and the column liner 2 is welded four times. In addition, there are cross-cross welds and sharp angle welds at the plate corners of these two structures, which require multiple welding and heating in a small area, resulting in stress concentration and large welding residual stress. Therefore, these two structures are prone to stress concentration, cracks, and corrosion problems during use, which in turn leads to leakage of the medium, and the maintenance of this position is difficult. Therefore, the welding structure between the top angle of the plate bundle and the column liner 2 is crucial to the product quality, reliability and service life of the fully welded plate heat exchanger core based on the S-shaped weld. The present invention can solve the above problems and ensure the reliability of the fully welded plate heat exchanger core based on the S-shaped weld.

[0099] In this embodiment, it is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and therefore it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

Claims

1. A fully welded plate heat exchanger core based on an S-shaped weld, characterized in that: It comprises a heat exchange plate (1), a column lining plate (2), a top plate (3), a bottom plate (4) and a baffle frame (5); The plurality of heat exchange plates (1) are sequentially connected from top to bottom to form a plate bundle, and four corners of the plate bundle form continuous S-shaped welding edges (6) from top to bottom; The column lining plates (2) are arranged at the four corners of the plate bundle, a continuous S-shaped insertion seam (21) is arranged at the bending part of the column lining plate (2) from top to bottom, the S-shaped welding edge (6) is inserted into the S-shaped insertion seam (21), and the S-shaped welding edge (6) and the column lining plate (2) are connected by welding; The top plate (3) and the bottom plate (4) are respectively provided at the upper end and the lower end of the plate bundle, and the four corners of the top plate (3) and the bottom plate (4) are connected to the column lining plate (2); Four baffle frames (5) are respectively arranged around the plate bundle, the upper and lower ends of the baffle frames (5) are respectively connected to the top plate (3) and the bottom plate (4), and the left and right ends of the baffle frames (5) are respectively connected to the column lining plates (2) on both sides thereof; The heat exchange plate (1) comprises a central plate (11) and four folded edges (12); The central plate (11) is a rectangular plate body, the four corners of the central plate (11) are provided with triangular cutouts (13), and the four sides of the central plate (11) are respectively provided with four folded edges (12); The two ends of the folded edge (12) extend to the triangular cutouts (13) on both sides thereof, and the bending directions of two adjacent folded edges (12) are opposite; the edge of the triangular cutout (13) and the edges of the two adjacent folded edges (12) form a welding edge, and the welding edges of the plurality of heat exchange plates (1) are sequentially connected to form the continuous S-shaped welding edge (6); The column lining plate (2) comprises a first vertical plate (22), a docking plate (23) and a second vertical plate (24) which are connected in sequence from left to right; A vertical plate smooth transition section (25) is provided between the butt joint plate (23) and the first vertical plate (22) and the second vertical plate (24); A heat exchange plate smooth transition section (14) is provided between the folded edge (12) and the center plate (11); The edge of the triangular cutout (13) is inserted into the portion of the S-shaped slot (21) located on the docking plate (23), the edge of the heat exchange plate smooth transition section (14) is inserted into the portion of the S-shaped slot (21) located on the vertical plate smooth transition section (25), and the edge of the folded edge (12) is inserted into the portion of the S-shaped slot (21) located on the first vertical plate (22) or the second vertical plate (24).

2. The fully welded plate heat exchanger core based on S-shaped weld according to claim 1, characterized in that: A group of support components (7) and a group of baffle system components (8) are respectively arranged in the middle of the two opposite baffle frames (5), and the two ends of the support components (7) or the two ends of the baffle system components (8) are respectively connected to the middle of the left and right sides of the corresponding baffle frame (5).

3. The fully welded plate heat exchanger core based on S-shaped weld according to claim 2, characterized in that: The baffle frame (5) comprises four baffle members (51) connected in sequence, the four baffle members (51) being detachably connected, and the baffle members (51) being connected to the top plate (3), the bottom plate (4) or the column lining plate (2) via a bolt assembly.

4. The fully welded plate heat exchanger core based on S-shaped weld according to claim 3 is characterized in that: The support assembly (7) comprises a support rod (71) and a connecting piece (72), one end of the support rod (71) being connected to one side of the baffle frame (5), the other end of the support rod (71) being threadedly connected to one end of the connecting piece (72), and the other end of the connecting piece (72) being connected to the other side of the baffle frame (5).

5. The fully welded plate heat exchanger core based on S-shaped weld according to claim 4 is characterized in that: The baffle system assembly (8) comprises a baffle plate (81) and a clamping member (82); the baffle plate (81) is vertically provided with clamping edges (811) on both left and right sides; Two of the clamping members (82) are respectively arranged on the left and right sides of the baffle frame (5), the two clamping members (82) are arranged opposite to each other, and opposite ends of the two clamping members (82) are each provided with a warping edge (821), and a mounting groove is formed between the warping edge (821) and the baffle frame (5); The two baffles (81) are fixed together in a vertically symmetrical manner and then inserted into the installation groove via the clamping edge (811) and fixed.

6. The fully welded plate heat exchanger core based on S-shaped weld according to claim 1, characterized in that: A head plate (9) is provided between the upper end of the plate bundle and the top plate (3); the head plate (9) has the same structure as the heat exchange plate (1); the height of the corrugated groove (10) on the head plate (9) is consistent with the height of the folded edge (12) on the upper portion of the head plate (9); the corrugated groove (10) on the head plate (9) abuts against the bottom surface of the top plate (3); and the edge of the folded edge (12) on the upper portion of the head plate (9) is welded to the bottom surface of the top plate (3); A tail plate (20) is provided between the lower end of the plate bundle and the bottom plate (4), folded edges (12) are provided on the upper parts of both sides of the tail plate (20), the bottom surface of the tail plate (20) abuts against the top surface of the bottom plate (4), and the four sides of the tail plate (20) are circumferentially welded to the top surface of the bottom plate (4).

7. The welding method of a fully welded plate heat exchanger core based on an S-shaped weld according to claim 1, characterized in that: The following steps are involved: Stacking the heat exchange plates (1) so that the gap between the folded edges (12) of two adjacent heat exchange plates (1) is less than 0.2 mm, and then welding the folded edges (12) of the two adjacent heat exchange plates (1) until the plate bundle is completed; The S-shaped welding edge (6) of the plate bundle is inserted into the S-shaped insertion slot (21) on the corresponding column lining plate (2), so that the S-shaped welding edge (6) extends to the outside of the S-shaped insertion slot (21), and then the S-shaped welding edge (6) and the column lining plate (2) are welded outside the column lining plate (2).

8. The welding method of a fully welded plate heat exchanger core based on an S-shaped weld according to claim 7, characterized in that: The following steps are also included: A left lining plate (26) and a right lining plate (27) are cut out of the plate, a plurality of slots (28) are provided at the middle of the left lining plate (26) and the right lining plate (27) that match each other, and an insert plate (29) is formed between the plurality of slots (28); and then the left lining plate (26) and the right lining plate (27) are bent into shape; Inserting the inserting plate (29) of the left lining plate (26) and the inserting plate (29) of the right lining plate (27) into the S-shaped welding edge (6) of the plate bundle, the left lining plate (26) and the right lining plate (27) are butted at the slot (28) and the inserting plate (29) to form the S-shaped insertion seam (21); The upper and lower parts of the left lining plate (26) are respectively welded to the upper and lower parts of the right lining plate (27), and the left lining plate (26) and the right lining plate (27) are connected to form the column lining plate (2).

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