Micro-channel heat exchanger and manufacturing method thereof

Abstract

The present application relates to heat exchanger technical field, it discloses a kind of microchannel heat exchanger and its manufacturing method, heat exchanger is fixed with multiple groups of longitudinal and transverse interlaced channel layer between upper and lower two layers of sealing plate, and spacing is fixed with baffle between channel layer;Channel layer includes multiple corrugated strips clamped between two side strips, and the corrugation of corrugated strip is towards two sides;The corrugated strip and side strip of adjacent channel layer in upper and lower are longitudinally and transversely interlaced, and curve heat exchange flow channel for turbulence is formed between adjacent corrugated strip and baffle.The manufacturing method provided by the present application, manufacturing process is simple, flow channel between corrugated strip can be obtained by stamping or bending, and flow channel formation does not need to bring pollution to environment without etching with etching liquid, and cost is lower;By optimizing heat exchanger channel structure, adjust the spacing between corrugated strip, can significantly increase heat exchange area;Multiple heat exchange layers are stacked together using multilayer composite structure, and heat exchange area can be substantially increased in limited space.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, and in particular to a microchannel heat exchanger and its manufacturing method. Background Technology

[0002] Printed Circuit Heat Exchangers (PCHEs) are widely used in industries such as petroleum, chemical, pharmaceutical, and aerospace. Currently, most microchannel heat exchangers utilize PCHEs for their flow channels. PCHE heat exchanger flow channels are formed by etching mirror-finish plates with extremely low roughness, and then multiple layers of these flow channels are stacked and diffused together to form a monolithic heat exchanger. Figure 1 Compared to shell-and-tube heat exchangers, PCHE heat exchangers typically have millimeter-scale microchannels for fluid flow. These microchannels offer higher heat exchange efficiency and a larger specific surface area, resulting in PCHE heat exchangers being characterized by high compactness and high heat exchange efficiency.

[0003] Despite the numerous advantages of PCHE heat exchangers, their manufacturing process involves photochemical etching of channels in the flow channel plate. This process generates environmentally polluting chemicals and has a long processing cycle. Furthermore, the dimensions and spacing of the flow channels on the flow channel plate are subject to minimum size limitations, making it difficult to utilize excess volume more effectively.

[0004] Therefore, existing PCHE heat exchangers and the processes used to manufacture them have the following drawbacks:

[0005] 1. Complex process. The etching process of PCHE channels usually requires many steps, including the use of strong acids and alkalis for chemical etching. The etching solution is expensive, causes great environmental pollution, and the raw materials for the channel plate have very high quality requirements.

[0006] 2. High manufacturing cost. The main cost lies in the etching of the flow channel plate. High-mirror-finish flow channel plates are made of stainless steel, which incurs high etching costs.

[0007] In addition, such as Figure 2 Currently, there are "Z" type plates on the market that can achieve a similar effect, but the "Z" type plates have lower precision and are suitable for channels larger than 2mm. Summary of the Invention

[0008] To overcome or alleviate one or more of the above-mentioned technical problems, the present invention aims to provide a microchannel heat exchanger and its manufacturing method. The flow channel form and structure of the microchannel heat exchanger abandon the complex processing technology of traditional PCHE flow channels, and simplify the manufacturing process and significantly reduce the manufacturing cost of the heat exchanger while ensuring heat exchange efficiency, pressure resistance and temperature resistance.

[0009] This invention provides the following technical solution:

[0010] On one hand, the present invention provides a microchannel heat exchanger, wherein multiple sets of crisscrossing channel layers are fixedly arranged between upper and lower sealing plates, and partitions are fixedly arranged between the channel layers at intervals; the channel layer includes multiple corrugated strips sandwiched between side strips on both sides, and the corrugations of the corrugated strips face to both sides; the corrugated strips and side strips of the upper and lower adjacent channel layers are arranged in a crisscross pattern, and a curved heat exchange channel for turbulence is formed between adjacent corrugated strips and partitions.

[0011] According to some embodiments, the sealing plate is a mirror panel with a thickness greater than 10 mm.

[0012] According to some embodiments, the partition is a mirror panel with a thickness of 0.1 to 1 mm.

[0013] According to some embodiments, the surface of the mirror panel is 4K-8K.

[0014] According to some embodiments, the mirror panel is selected from stainless steel sheet.

[0015] According to some embodiments, the thickness of the edge strip is the same as the height of the corrugated strip.

[0016] According to some embodiments, the corrugated strip has a thickness ranging from 0.1 to 1 mm and a width ranging from 0.5 to 2 mm.

[0017] According to some implementations, the inward-facing corrugations of the edge strip correspond to the same corrugations of the corrugated strip.

[0018] On the other hand, the present invention provides a method for manufacturing the above-mentioned microchannel heat exchanger, which includes the following steps:

[0019] S1: First place a sealing plate at the bottom. The sealing plate is a mirror panel with a thickness of more than 10mm.

[0020] S2: Place a side strip on each side of the sealing plate, and arrange multiple corrugated strips in the middle according to the design spacing to form a flow channel layer;

[0021] S3: Place another partition, which is a mirror panel with a thickness of 0.1 to 1 mm;

[0022] S4: Rotate 90 degrees and place another channel layer following the steps in S2;

[0023] S5: Repeat S2 to S4 until the designed layer number is reached, then place a sealing plate on the top layer;

[0024] S6: The microchannel heat exchanger is fabricated by integral welding using vacuum diffusion welding.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention provides a microchannel heat exchanger and its manufacturing method. The microchannel heat exchanger manufactured according to this method has a simple manufacturing process; the flow channels between the corrugated strips can be obtained by stamping or bending, and the flow channel formation does not require etching with a corrosive liquid, thus avoiding environmental pollution. Furthermore, it has significant advantages in cost control, with both raw material and processing costs being significantly lower than those of PCHE (Printed Circuit Board Heat Exchanger).

[0027] In terms of heat exchange, design optimizations include: significantly increasing the heat exchange area by optimizing the heat exchanger channel structure and adjusting the spacing between the corrugated strips. A multi-layer composite structure, stacking multiple heat exchange layers together, can also greatly increase the heat exchange area within a limited space.

[0028] Optimize fluid channels: Design reasonable fluid channels to ensure that the fluid can be evenly distributed in the heat exchanger. The channels adopt an arc structure to reduce flow resistance and dead angles, improve fluid velocity and turbulence, thereby promoting heat transfer. Attached Figure Description

[0029] Figure 1 A schematic diagram of a printed circuit board heat exchanger provided as background information for this invention.

[0030] Figure 2 The background diagram of the "Z" shaped plate is provided for the purpose of this invention.

[0031] Figure 3 This is a schematic diagram of the structure of a microchannel heat exchanger provided in an embodiment of the present invention.

[0032] Figure 4 This is a schematic diagram of a corrugated strip provided in an embodiment of the present invention.

[0033] Figure 5 This is a schematic diagram of the edge strip provided in an embodiment of the present invention.

[0034] Figure 6 This is a layered schematic diagram of a microchannel heat exchanger provided in an embodiment of the present invention.

[0035] In the picture:

[0036] Sealing plate 1, channel layer 2, corrugated strip 2-1, edge strip 2-2, first channel layer 21, second channel layer 22, partition 3. Detailed Implementation

[0037] The present invention will now be described in detail with reference to embodiments and accompanying drawings. However, it should be understood that the embodiments and drawings are for illustrative purposes only and do not constitute any limitation on the scope of protection of the present invention. All reasonable modifications and combinations included within the inventive spirit of the present invention fall within the scope of protection of the present invention.

[0038] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "front," and "rear," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication of two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0039] This invention is a high-efficiency, high-pressure resistant, and high-temperature resistant microchannel heat exchanger formed by diffusion welding of strip-shaped thin plates and upper and lower partitions.

[0040] The present invention will be further described below with reference to the accompanying drawings.

[0041] Example 1

[0042] This embodiment provides a microchannel heat exchanger, which, in terms of structure, such as... Figure 3 .

[0043] The heat exchanger, from top to bottom, includes a top sealing plate 1, several crisscrossing channel layers, and a bottom sealing plate 1. Baffles 3 are spaced apart between each adjacent channel layer 2. The channel layers 2 are stacked in multiple layers to form fluid heat exchange channels. For example... Figures 4-6 The channel layer 2 includes multiple corrugated strips 2-1 arranged between the two side strips 2-2. The corrugations of the corrugated strips 2-1 face to both sides, and the corrugations of the side strips 2-2 facing inward correspond to the same corrugation shape as the corrugated strips 2-1. The adjacent channel layers 2 are arranged in a crisscross pattern. A curved heat exchange channel for turbulence is formed between adjacent corrugated strips 2-1 and the partition 3.

[0044] like Figure 6In the middle, the upper first channel layer 21 and the lower second channel layer 22 are staggered at 90° angles. The corrugated strips 2-1 in this type can all be made using a single mold, which also facilitates assembly.

[0045] Hot fluid enters the first channel layer 21 of the microchannel heat exchanger through hot working fluid pipes and is evenly distributed; cold fluid enters the second channel layer 22 through cold working fluid pipes and is also evenly distributed. This forms a uniform heat exchange between several first channel layers 21 and second channel layers 22.

[0046] A single channel layer 2 is supported by side strips 2-2 and arranged in multiple rows of corrugated strips 2-1 to form a cross-flow curved medium channel, which greatly increases the heat exchange efficiency.

[0047] The manufacturing method of this heat exchanger includes the following steps:

[0048] 1) First, place a sealing plate 1 at the bottom. The sealing plate 1 is usually a stainless steel plate with a thickness of more than 10mm (the final thickness is determined by the strength check during the design). Its function is to withstand the high pressure from diffusion welding and to bond the adjacent flow channels to form a seal.

[0049] 2) Place one edge strip 2-2 on each side of the bottom sealing plate 1, and arrange multiple corrugated strips 2-1 in the middle according to the design spacing to form a flow channel layer 2.

[0050] 3) Cover the top with a partition plate 3. The partition plate 3 is a 0.1-1mm stainless steel plate that is thinner than the sealing plate 1 (the plate thickness is selected according to the heat exchange requirements). It not only acts as the force transmission body of diffusion welding, but also separates the hot and cold sides of the channel; through diffusion welding, it forms an adhesive seal with the contact surface of the upper and lower corrugated strips 2-1 and the edge strips 2-2.

[0051] 4) Rotate 90 degrees and place another flow channel layer 2 in the other direction following step 2).

[0052] 5) Stack the layers in a cyclical manner according to steps 2) to 4), assemble according to the designed number of layers, and place the top layer with the top sealing plate 1.

[0053] 6) Then, the microchannel heat exchanger is formed by vacuum diffusion welding.

[0054] In addition to stainless steel, the sealing plate 1 and partition plate 3 can also be made of other mirrored materials, with the surface of the mirrored plate being 4K-8K.

[0055] Edge strip 2-2 acts as a pressure support for corrugated strip 2-1, preventing plastic deformation due to excessive pressure during diffusion welding. The thickness of edge strip 2-2 should be equal to the thickness of corrugated strip 2-1.

[0056] The corrugated strip 2-1 is the core component. Its curved shape facilitates its fixation to the partition plate 3 or the sealing plate 1. A diffusion weld is used to form a sealed weld between its upper and lower surfaces, and the seal between the two corrugated strips 2-1 and the partition plate 3 forms a curved flow channel. This flow channel design facilitates turbulence when the medium passes through, significantly increasing the heat exchanger's heat exchange efficiency.

[0057] The manufacturing process of the corrugated strip 2-1 is simple. The corrugated strip 2-1 typically has a small thickness (0.1-1mm) and width (0.5-2mm), which gives it unique advantages in certain applications, such as ease of bending, winding, and processing. First, the stainless steel raw material sheet is cut into strips using a cutting machine or wire cutting. Then, a mold with the corresponding curvature shape is made, and the strips are pressed by a press. Several corrugated strips 2-1, along with two edge strips 2-2, form a channel layer 2. Two adjacent channel layers 2 are orthogonal, and a partition 3 is placed between the two layers. Several layers are stacked together and formed into a single microchannel heat exchanger through a vacuum diffusion welding process.

[0058] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A microchannel heat exchanger, wherein multiple sets of crisscrossing channel layers are fixed between upper and lower sealing plates, characterized in that: The channel layers are fixedly spaced with partitions; each channel layer includes multiple corrugated strips sandwiched between side strips, with the corrugations of the strips facing both sides; the corrugated strips and side strips of adjacent channel layers are arranged in a crisscross pattern, forming a curved heat exchange channel for turbulence between adjacent corrugated strips and partitions; the thickness of the corrugated strips ranges from 0.1 to 1 mm, and the width ranges from 0.5 to 2 mm; the sealing plate is a mirror panel with a thickness greater than 10 mm; the partition is a mirror panel with a thickness of 0.1 to 1 mm.

2. The microchannel heat exchanger according to claim 1, characterized in that: The surface of the mirror panel is 4K-8K.

3. The microchannel heat exchanger according to claim 2, characterized in that: The mirror panel is made of stainless steel.

4. The microchannel heat exchanger according to claim 1, characterized in that: The thickness of the edge strip is the same as the height of the corrugated strip.

5. The microchannel heat exchanger according to claim 4, characterized in that: The inward-facing corrugations of the edge strip correspond to the same corrugations of the corrugated strip.

6. A method for manufacturing a microchannel heat exchanger as described in any one of claims 1 to 5, characterized in that: Includes the following steps: S1: First place a sealing plate at the bottom. The sealing plate is a mirror panel with a thickness of more than 10mm. S2: Place a side strip on each side of the sealing plate, and arrange multiple corrugated strips in the middle according to the design spacing to form a flow channel layer; S3: Place another partition, which is a mirror panel with a thickness of 0.1~1mm; S4: Rotate 90 degrees and place another channel layer following the steps in S2; S5: Repeat S2~S4 until the designed layer number is reached, and place a sealing plate on the top layer; S6: The microchannel heat exchanger is fabricated by integral welding using vacuum diffusion welding.

Images