Frame type sealing strip for brazing of aluminum plate-fin heat exchanger core

Abstract

The invention belongs to the technical field of heat exchanger parts, and particularly relates to a frame type sealing strip for brazing of an aluminum plate-fin heat exchanger core. Comprising a sealing strip body of a rectangular frame type structure, and four corners of the sealing strip body are designed to extend outwards; one direction of the sealing strip body serves as a channel side, and a row of hole groove flow channels similar to the shape like the Chinese character'hui 'are formed in the channel side. And the other direction is a solid closed side. According to the integrated frame type sealing strip design, the strength of the whole core body can be effectively guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat exchanger components, and particularly relates to a frame seal for brazing an aluminum plate-fin heat exchanger core body. Background Art

[0002] Plate-fin heat exchangers utilize the disturbance of fins to the fluid, causing the boundary layer to continuously break, thus having a relatively large heat transfer coefficient. Among them, aluminum plate-fin heat exchangers are widely used in the fields of machinery, petroleum, electronics, and aerospace due to their strong adaptability, light weight, high heat conduction efficiency, and compact structure. Among plate-fin heat exchangers classified by materials, aluminum ones account for the vast majority. An aluminum plate-fin heat exchanger mainly consists of a core body and a head. The core body is the core component of the aluminum plate-fin heat exchanger and is formed by vacuum brazing parts such as fins, partitions, and seals stacked layer by layer in a specific arrangement. Vacuum brazing technology has become the most mainstream welding method for aluminum plate-fin heat exchanger cores at present because of its advantages such as preventing product contamination, not requiring the addition of fluxes, and being able to weld complex components.

[0003] Among the core body parts, the seal, as an important component, relies on the brazing seam formed by the brazing material on the partition to play the role of sealing the hot and cold refrigerant channels between the partition and the seal. At present, the seals in aluminum heat exchanger cores are generally made of profiles processed into long strips, and the cross-sectional shapes include types such as rectangular and I-shaped. After brazing, due to the need for airtightness tests, it is generally necessary to carry out argon arc welding surfacing on the edges to build up a height of about 10 mm and then mill out a plane to pass the airtightness test through a pressing plate fixture. Inevitably, this will cause burn defects in the fins near the seal due to argon arc welding, which not only affects the product appearance but also has the risk of generating foreign matters. In addition, argon arc welding surfacing not only requires high operating skills for welders, but there will also be a situation where multiple argon arc welds intersect and affect each other when assembling the head and flange components, and local positions are prone to failure problems under extremely high-pressure working conditions. Summary of the Invention

[0004] Object of the Invention: To solve the problems that local positions are prone to failure during welding under extremely high-pressure working conditions and various adverse effects that may be caused by argon arc welding surfacing, the present invention proposes a seal for brazing an aluminum plate-fin heat exchanger core body.

[0005] Technical Solution: To achieve the above object of the invention, the present invention designs a frame seal for brazing an aluminum plate-fin heat exchanger core body, which includes a rectangular frame-type structural seal body, and the seal body is designed to extend outward at all 4 corners; one direction of the seal body is used as the channel side, and a row of "return" - shaped hole groove channels are opened on the channel side; the other direction is a solid closed side.

[0006] Further, the body is made of a blank piece produced by profile extrusion forming and processed by longitudinal cutting, which is no longer a traditional long strip shape of square or I-shaped, but a whole rectangular frame structure.

[0007] Further, the overall height of the body is directly determined during profile extrusion forming processing according to the height of the channel of the heat exchanger core, and the parallelism of the upper and lower surfaces in the height direction is required to be within 0.05 mm.

[0008] Further, the two rows of rectangular holes and grooves on the channel side of the body are 3.8 mm wide, the round corners are R1.5 mm, and the spacing around the rectangular holes and grooves is 0.5 mm. If a complete rectangular hole and groove cannot be satisfied from one side to the other side, the corresponding part of the rectangular hole and groove is reserved to ensure that the channel has sufficient flow area.

[0009] Further, the body extends 10 mm outward from each of the four corners and then has a R5 mm round corner to ensure the local position strength; the advantage of this design is that after the core brazing is completed, the extended position can be directly milled flat for air tightness test without surfacing.

[0010] Further, solid partitions are arranged on the channel side according to requirements to fix and space the adjacent two flow channels.

[0011] Further, a 10 mm protrusion is made outward at both ends of the solid partition.

[0012] Further, the body has a round corner with R0.1-R0.3, the surface roughness of the upper and lower surfaces is required to be above Ra6.3, and the rest is required to be Ra12.5.

[0013] Technical effects: 1. The integrated frame type seal design of the application can effectively ensure the strength of the whole core.

[0014] 2. The extension design at the four corner positions of the seal can avoid the burnout defect of the fins near the seal caused by argon arc welding surfacing, ensure the appearance of the product, and avoid the risk of excess material. The extension design can avoid the situation that multiple argon arc welds are intertwined with each other during the assembly welding of the head and the flange part, which can easily lead to failure in the local position under extremely high pressure working conditions.

[0015] 3. The "back" type flow channel design on the channel side of the application can effectively protect the fins on this side from being damaged during long-term use, thereby preventing the generation of excess material. DETAILED DESCRIPTION

[0016] Figure 1 A frame type seal for brazing an aluminum plate fin heat exchanger core is provided for the embodiment 1 of the application; Figure 2A frame type sealing strip blank for brazing an aluminum plate-fin heat exchanger core.

[0017] Wherein, 1 is the sealing strip body, 2 is the channel side, 3 is the "Hui" hole groove flow channel on the channel side, 4 is the closed side, and 5 is the partition strip. DETAILED DESCRIPTION

[0018] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0019] Embodiment 1 In a certain type of aluminum plate-fin heat exchanger core, because the product use condition is strictly required, 1.65 MPa total 120,000 times of pressure alternating test needs to be completed, so the strength of the core and the argon arc welding peak is very high. Referring to Figure 1 , a frame type sealing strip for brazing an aluminum plate-fin heat exchanger core is specifically designed. The sealing strip can be obtained by wire cutting processing from a profile blank. Figure 2 The blank of the sealing strip in the embodiment of the present application is processed by wire cutting from a profile extrusion formed part, which is a whole rectangular frame double channel structure. The body 1 is 6 mm high in whole, the parallelism of the upper and lower surfaces in the height direction is required to be within 0.05 mm, and the width is 5 mm. The body 1 in one direction is the channel side 2, which is 76 mm and 38 mm long respectively. There are two rows of rectangular hole grooves 3 on the upper surface, which are similar to "Hui" structure, 3.8 mm wide, round angle R1.5 mm, and the rectangular square groove 3 is 0.5 mm apart around. If the other side cannot meet the requirements of a complete rectangular square groove, the corresponding part of the hole groove 3 is reserved, and the partition strip in the middle is a solid structure with a width of 5 mm.

[0020] The other direction of the body 1 except the channel side 2 is the closed side 4 for fixing the flow direction. The body 1 is designed to extend at the four corners, each corner extends 10 mm to the outside of the two sides and then reverses R5 mm of the round angle to ensure the local position strength. The partition strip 5 is also designed to extend 10 mm on both sides. In addition, the body 1 is not rounded to R0.1-R0.3, and the surface roughness of the upper and lower surfaces should be more than Ra6.3, and the rest should be guaranteed to be Ra12.5. The sealing strip is installed in the heat exchanger product processed by the hot edge channel of a certain type of aluminum plate-fin heat exchanger core, which has a good appearance, no fin damage caused by argon arc welding overlaying, and the overall strength is greatly increased. The 1.65 MPa total 120,000 times of pressure alternating test is successfully completed.

[0021] The gasket profile extrusion forming is to put the pre-prepared blank into the extrusion cylinder, apply pressure, and make the material be extruded and formed from the opening of the container. The material is in the state of unequal three-dimensional compression stress during extrusion, and the strain state is elongation along the axial direction.

[0022] The extension design at the four corner positions of the gasket can avoid the burnout defects of the fins near the gasket caused by argon arc welding overlaying, ensure the appearance of the product, and ensure the risk of no excess material. The extension design can avoid the situation that multiple argon arc welds are interwoven when the head and the flange parts are assembled and welded, and this situation is easy to cause local failure under extremely high pressure working conditions.

[0023] The above specific embodiments or cases are only used to explain the technical solutions of the present application, and are not limited to the present application. The parts not described in detail are regarded as conventional technical means or common knowledge in the art; it can be understood by those skilled in the art that: based on the design idea of the present application, the technical solutions recorded in the foregoing embodiments can be modified adaptively, or part or all of the technical features can be replaced equivalently, and these modified, equivalent replaced, and adaptively improved technical solutions do not deviate from the technical essence of the present application, and should be covered within the protection scope of the present application.

Claims

1. A frame-type sealing strip for brazing the core of an aluminum plate-fin heat exchanger, characterized in that... It includes a rectangular frame - type structural seal body (1), and the seal body (1) is designed to extend outward at all four corners; one direction of the seal body (1) serves as the channel side (2), and a row of "return" - shaped hole - groove channels (3) is opened on the channel side (2); the other direction is the solid - closed side (4).

2. The frame-type sealing strip for brazing the core of an aluminum plate-fin heat exchanger as described in claim 1, characterized in that, The seal body (1) is processed from a blank part produced by profile extrusion into a whole rectangular frame structure through wire cutting.

3. The frame-type sealing strip for brazing the core of an aluminum plate-fin heat exchanger as described in claim 2, characterized in that... The overall height of the seal body (1) is directly determined during the profile extrusion processing according to the height of the heat exchanger core channel, and the parallelism requirement of the upper and lower surfaces in the height direction is within 0.05 mm.

4. The frame-type sealing strip for brazing the core of an aluminum plate-fin heat exchanger as described in claim 3, characterized in that... The two rows of rectangular holes (3) on the channel side (2) of the seal body (1) are 3.8 mm wide, with a fillet radius of R1.5 mm, and the spacing around the rectangular holes (3) is 0.5 mm. If a complete rectangular hole (3) cannot be satisfied from one side to the other side, the corresponding part of the rectangular hole (3) is retained to ensure that the channel has sufficient flow - passage area.

5. The frame-type sealing strip for brazing the core of an aluminum plate-fin heat exchanger as described in claim 4, characterized in that... Each of the four corners of the seal body (1) extends 10 mm outward on both sides and then has a fillet with a radius of R5 mm to ensure the strength of local positions.

6. A frame-type sealing strip for brazing the core of an aluminum plate-fin heat exchanger as described in claim 1 or 4, characterized in that, Solid partition bars (5) are arranged on the channel side (2) as required to fix and separate adjacent two channels.

7. The frame-type sealing strip for brazing the core of an aluminum plate-fin heat exchanger as described in claim 6, characterized in that... The two ends of the solid partition bar (5) are designed to protrude 10 mm outward.

8. The frame-type sealing strip for brazing the core of an aluminum plate-fin heat exchanger as described in claim 1, characterized in that... The rounded corners of the seal body (1) have a radius of R0.1 - R0.3, the surface roughness of the upper and lower surfaces should reach Ra6.3 or more, and the rest is ensured to be Ra12.5.

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