A brazed plate-fin heat exchanger

Abstract

A brazed plate-fin heat exchanger with clamped tubes comprises a plate bundle body (1) which is composed of two or more than two layer channel units alternately stacked, characterized in that at least one of the two or more than two layer channel units is a tube layer channel unit (11), the tube layer channel unit (11) comprises a plurality of straight tubes (111), a plurality of supports (112) and a plurality of connecting strips (113), the supports (112) clamping the straight tubes (111) from both sides, the connecting strips (113) are linear strips embedded between adjacent supports (112), the supports (112) and the connecting strips (113) are combined to form a plate-shaped body, after overall brazing, the two sides of the connecting strips (113) are brazed to the adjacent layer channel units, so that the supports (112) clamp and fix the straight tubes (111), and the whole tube layer channel unit (11) becomes an integral whole.

Description

Technical Field

[0001] This invention relates to plate-fin heat exchangers, and more specifically to a plate-fin heat exchanger with brazed tube clamps. Background Technology

[0002] Plate-fin heat exchangers are a type of high-efficiency heat exchanger that uses fins as heat transfer elements. They are characterized by high heat transfer efficiency, compact structure, expandable number of heat exchange channels, high adaptability, and light weight. Therefore, they are widely used in gas-to-gas, gas-to-liquid, and liquid-to-liquid two- or more-channel heat exchange equipment, and are currently commonly used in the field of air separation equipment.

[0003] For existing technology, please refer to the technical standard "NB / T 47006—2019 Aluminum Plate-Fin Heat Exchanger". Standard plate-fin heat exchangers consist of a plate bundle, end caps, nozzles, and supports, etc. The plate bundle is constructed by alternating superimposed and brazed two or more layered channel units. Taking two types of layered channel units as an example, both the first and second types consist of fins, guide vanes, seals, and baffles. Fluid inlets and outlets for each of the two channel units are led out from their respective circumferential sides. Then, end caps are welded along the thickness direction to the side of the plate bundle to enclose the fluid inlets and outlets of the same type of channel unit. Finally, nozzles are welded onto the end caps as the overall inlet and outlet, thus forming a heat exchanger.

[0004] However, existing plate-fin heat exchangers, whose channels are made of aluminum fins, suffer from significant strength reduction at temperatures above 60°C and are not corrosion-resistant. Therefore, existing plate-fin heat exchangers are not pressure-resistant, high-temperature resistant, corrosion-resistant, and prone to clogging, with a maximum withstand capacity of 15 MPa, thus limiting their applications. Consequently, for high-pressure, high-temperature, or corrosive fluids, only coil-type heat exchangers, which are more expensive and have much lower heat transfer efficiency, are currently available on the market. Summary of the Invention

[0005] The purpose of this invention is to provide a brazed plate-fin heat exchanger with clamped tubes, which, while retaining the high heat exchange efficiency of the original plate-fin heat exchanger, makes it suitable for high-pressure, high-temperature, or corrosive fluids.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a brazed plate-fin heat exchanger with brazed tube clamps, comprising an integrally brazed plate bundle, which is composed of two or more layer channel units stacked alternately; at least one of the two or more layer channel units is a tube layer channel unit, which includes multiple straight tubes, multiple supports, and multiple connecting strips; the multiple straight tubes are arranged in parallel on a plane, with one end of each straight tube connected to a converging inlet and the other end connected to a converging outlet, thus forming a parallel structure of the tube cavities of each straight tube; each of the above... Each support corresponds to a straight tube. Specifically, each support consists of two support strips facing each other, with grooves on the opposite surfaces of the support strips corresponding to the straight tube. The straight tube is accommodated in the grooves of the support strips facing each other, meaning the support clamps the straight tube from both sides. The connecting strips are straight plates embedded between adjacent supports. Multiple supports and multiple connecting strips are assembled to form a plate-like body. After the entire assembly is brazed, each side of the connecting strip is brazed to the adjacent layer channel unit to clamp and fix the straight tube, making the entire tube layer channel unit a whole.

[0007] In the above scheme, before the overall brazing is formed, brazing foil is provided between the opposite surfaces of the support strip and in its groove. The straight tube is made of a brazing-compatible material or the surface of the straight tube is coated. After the overall brazing is formed, the groove wall of the support strip and the straight tube are brazed together, as are the two support strips.

[0008] Based on the above technical solution, the present invention has the following advantages and effects:

[0009] This invention innovatively transforms a layered channel unit in existing plate-fin heat exchangers into a tube-layered channel unit primarily composed of straight tubes. The straight tubes' tubular structure improves their pressure resistance, and their smooth internal walls resist sedimentation and blockage. Furthermore, the straight tubes are fixed by clamping with supports, eliminating the need for brazing in material selection and greatly expanding the range of materials that can be used (such as copper, high-temperature resistant plastics, stainless steel, and titanium), thereby further enhancing their pressure resistance, temperature resistance, and corrosion resistance. In use, high-temperature, high-pressure, or corrosive fluids can be circulated within the tube-layered channel unit, successfully expanding its applicability while maintaining the high heat exchange efficiency of the original plate-fin heat exchanger.

[0010] Furthermore, since all components (support strips, connecting strips) in its pipe layer channel unit, except for straight pipes, are strips with equal cross-sections, they can all be made of profiles, making them easy to manufacture and cost-effective. Attached Figure Description

[0011] Appendix Figure 1 This is a three-dimensional schematic diagram of Embodiment 1 of the present invention;

[0012] Appendix Figure 2 This is a three-dimensional schematic diagram of a tube-layer channel unit according to an embodiment of the present invention;

[0013] Appendix Figure 3 This is an exploded view of a tube-layer channel unit according to Embodiment 1 of the present invention;

[0014] Appendix Figure 4 This is a schematic diagram of a normal layer channel unit according to Embodiment 1 of the present invention;

[0015] Appendix Figure 5 This is a three-dimensional schematic diagram of Embodiment 2 of the present invention.

[0016] In the above figures: 1. Plate bundle; 11. Pipe layer channel unit; 111. Straight pipe; 112. Support; 1121. Support strip; 11211. Groove; 113. Connecting strip; 12. Ordinary layer channel unit; 121. Fin; 122. Guide vane; 123. Seal; 124. Partition; 2. End cap; 3. Partition. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0018] Example 1: See Figures 1-4 As shown:

[0019] A plate-fin heat exchanger with brazed tube clamps includes an integrally brazed plate bundle 1 and end caps 2 disposed on the plate bundle 1.

[0020] See Figures 1-4 As shown, the plate bundle 1 is composed of two or more layer channel units stacked alternately. At least one of these layer channel units is a tubular channel unit 11, while the other channel units are existing ordinary layer channel units 12 composed of fins 121, guide vanes 122, seals 123, and partitions 124. Figure 4 As shown.

[0021] See Figures 1-4 As shown, the pipe layer channel unit 11 includes multiple straight pipes 111, multiple supports 112, and multiple connecting strips 113.

[0022] The straight pipes 111 are arranged in parallel on a plane, with one end of each pipe connected to a converged inlet and the other end connected to a converged outlet, thus forming a parallel structure of the lumens of the straight pipes. The number of converged inlets and outlets can be one or more; that is, the straight pipes of the pipe layer channel unit 11 can be connected to the same converged inlet, or multiple converged inlets can be connected, so that the straight pipes 111 of the pipe layer channel unit 11 form a group to carry the same medium, or the straight pipes of the pipe layer channel unit 11 are divided into two or three groups to carry different media. Figures 1-4The total imports and total exports are omitted from the chart.

[0023] Each of the aforementioned supports 112 is configured corresponding to a straight tube 111. Specifically, each support 112 consists of two support strips 1121 arranged face-to-face, and the opposing surfaces of the support strips 1121 have grooves 11211 corresponding to the straight tube 111. The straight tube 111 is accommodated in the grooves 11211 of the face-to-face support strips, that is, the supports 112 clamp the straight tube 111 from both sides. The connecting strips 113 are straight plates that are embedded between adjacent supports 112. The multiple supports 112 and multiple connecting strips 113 are assembled to form a plate-like body. After the entire assembly is brazed, the two sides of the connecting strips 113 are brazed to the adjacent layer channel unit, so that the supports 112 clamp and fix the straight tube 111, and the entire tube layer channel unit 11 becomes a whole.

[0024] At this point, the connecting strip 113 serves a connecting and supporting function, restricting the relative position of the support strip 1121, allowing the support strip 1121 to clamp and fix the straight tube 111. A small gap may exist between the groove wall of the support strip 1121 and the tube wall of the straight tube 111, or this gap may be filled with thermally conductive adhesive. The mating surfaces of the connecting strip 113 and the support strip 1121 can be directly abutted or brazed after the application of brazing foil.

[0025] Specifically, the partition 124 of the ordinary layer channel unit 12 is a composite plate with brazing foil on both sides. Therefore, after brazing, the two sides of the connecting strip 113 are brazed to the partition 124 of the adjacent layer channel unit. The outer side of the support strip 1121 of the bracket 112 is also brazed to the partition 124 of the adjacent layer channel unit. The bracket 112 clamps and fixes the straight pipe 111 from both sides, so that the entire pipe layer channel unit 11 becomes a whole.

[0026] To further improve heat transfer efficiency and fixation reliability, brazing foil is provided between the opposite surfaces of the support strip 1121 and in its groove 11211 before the overall brazing is formed. The straight tube 111 is made of a brazing-compatible material or the surface of the straight tube 111 is coated. After the overall brazing is formed, the groove wall of the support strip 11211 and the straight tube 111, as well as the two support strips 1121, are brazed together so that the heat (or cold) of the straight tube 111 can be directly conducted to the support strip 1121.

[0027] When the outermost layer channel unit of the entire plate-fin heat exchanger is a tube layer channel unit 11, a partition plate 3 shall be added to the outer side of the outermost tube layer channel unit 11.

[0028] In this embodiment, the material selection for the straight pipe 111 does not need to consider brazing; materials other than aluminum (such as copper, high-temperature resistant plastics, stainless steel, titanium, etc.) can be used, thereby further improving its pressure resistance, temperature resistance, or corrosion resistance. In use, high-temperature, high-pressure, or corrosive fluids can be circulated within the straight pipe 111 of the pipe layer channel unit 11, while low-pressure fluids with no special requirements can be circulated within the ordinary layer channel unit 12. This successfully expands the applicability range while retaining the high heat exchange efficiency advantage of the original plate-fin heat exchanger.

[0029] Example 2: See Figure 5 As shown:

[0030] A plate-fin heat exchanger with brazed clamped tubes includes an integrally brazed plate bundle 1 and end caps 2 disposed on the plate bundle 1. The only difference from other embodiments is that the straight tubes 111 are multiple tubes arranged side-by-side and leaning together to form a group, specifically four tubes leaning together as a group. The support 112 and the straight tubes 111 are arranged in a one-to-many configuration. Figure 5 For example, there is a pair of four. Each bracket 112 has four grooves 11211 on its bracket strip 1121, which correspond to the four straight tubes 111 leaning together.

[0031] Everything else is the same as in Example 1, and will not be repeated here.

[0032] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A brazed plate-fin heat exchanger comprising a plate bundle body (1) integrally brazed, the plate bundle body (1) being composed of two or more layer channel units alternately stacked, characterized in that: at least one of the two or more layer channel units is a tube layer channel unit (11), the tube layer channel unit (11) comprising a plurality of straight tubes (111), a plurality of supports (112) and a plurality of connecting strips (113); the plurality of straight tubes (111) are arranged in parallel on a plane, each straight tube (111) being connected to a collective inlet at one end and to a collective outlet at the other end, so that the cavities of the straight tubes (111) are in parallel connection; the straight tubes (111) are made of a material other than aluminum; each support (112) corresponds to a straight tube (111), and each support (112) is composed of two support strips (1121) arranged face to face, and a groove (11211) is formed on the opposite surface of each support strip (1121) corresponding to the straight tube (111), the straight tube (111) being accommodated in the groove (11211) of the face-to-face arranged support strips, i.e. the support (112) clamps the straight tube (111) from both sides; the connecting strip (113) is a straight linear strip, which is embedded between adjacent supports (112); the plurality of supports (112) and the plurality of connecting strips (113) form a plate-shaped body; after integrally brazing, the connecting strips (113) are brazed to the adjacent layer channel units on both sides to fix the straight tubes (111) clamped by the supports (112), and the entire tube layer channel unit (11) becomes a whole. before integrally brazing, brazing foils are arranged between the opposite surfaces of the support strips (1121) and in the grooves (11211), and the straight tubes are made of a brazable material or the surface of the straight tubes is plated, so that after integrally brazing, the groove walls of the support strips (1121) and the straight tubes (111) and the two support strips (1121) are brazed.

2. The brazed plate-fin heat exchanger of claim 1, wherein: ​

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