Heat exchanger

Abstract

The application discloses a heat exchanger, comprising a first fluid channel and a second fluid channel arranged adjacently, the first fluid channel is formed by a first plate and a second plate, the second fluid channel is formed by the second plate, a fin plate and a third plate, the second plate comprises a second base plate and a plurality of second protrusions, a second groove is formed between adjacent second protrusions, the second protrusion and the second groove form a second pit and a second flat part respectively on a side facing the fin plate, the second pit comprises a pit bottom, the fin plate is in contact with at least part of the second flat part, along the length direction of the heat exchanger, the distance between the pit bottoms of adjacent second pits is a1, the minimum size of the second flat part between adjacent second pits along the length direction of the heat exchanger is a2, wherein a2≤0.3a1. The heat exchanger of the application reduces the pressure drop of the second fluid channel, and improves the mixing of the fluid at the second pit and the fin plate, thereby improving the heat exchange effect.

Description

Technical Field

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

[0002] As a high-efficiency and compact heat exchanger, heat exchangers are widely used in industries such as refrigeration and air conditioning, and new energy vehicles. With the continuous improvement of requirements in terms of energy efficiency, weight, and installation, the high-efficiency and compact technical characteristics of heat exchangers need to be further improved.

[0003] Heat exchangers typically consist of multiple overlapping plates, with fluid channels formed between adjacent plates. The medium within these channels exchanges heat through the plates. To improve heat exchange performance, discrete protrusions are placed on the first fluid channel side of some plates to increase the heat exchange area of ​​the first fluid channel. Fins are placed on the second fluid channel side of the plates to increase the heat exchange area of ​​the second fluid channel. To further enhance the heat exchange effect of the second fluid channel, more fins are usually placed in the flow direction of the second fluid to disturb and obstruct the fluid, allowing the second fluid to fully exchange heat with the fins and improving the heat exchange effect. However, this also increases the flow resistance of the second fluid, requiring higher pumping power. Summary of the Invention

[0004] The purpose of this application is to provide a heat exchanger that not only improves the heat exchange effect of the entire heat exchanger, but also helps to reduce the flow resistance of the second fluid channel.

[0005] This application provides a heat exchanger, including at least a first fluid channel and a second fluid channel arranged adjacent to each other. The first fluid channel is formed by at least a first plate and a second plate stacked together, and the second fluid channel is formed by at least a second plate, a third plate, and a finned plate located between the second plate and the third plate stacked together.

[0006] The first plate includes a first substrate and a plurality of first protrusions protruding toward the second plate, with a first groove formed between adjacent first protrusions; the second plate includes a second substrate and a plurality of second protrusions protruding toward the first plate, with a second groove formed between adjacent second protrusions; the first protrusions and the second protrusions are disposed opposite to each other.

[0007] The second protrusion forms a second recess on the side facing the fin plate, the second recess including a bottom and a side portion of the recess, and the second groove forms a second flat portion surrounding the second recess on the side facing the fin plate, and the fin plate facing the second plate contacts at least a portion of the second flat portion.

[0008] The finned plate divides the second fluid channel into a plurality of first sub-channels. At least a portion of the first sub-channels are in communication with the second recess. Along the length of the heat exchanger, the distance between the bottoms of adjacent second recesses is a1, and the minimum dimension of the second flat portion between adjacent second recesses along the length of the heat exchanger is a2, wherein a2≤0.3a1.

[0009] Since one side of the second plate contacts the first fluid and the other side contacts the second fluid, the structure of the second plate directly affects the heat exchange effect between the first fluid channel side and the second fluid channel side, and thus affects the heat exchange effect between the first fluid channel and the second fluid channel. This application addresses this by providing multiple second protrusions on the second plate that protrude towards the first plate, i.e., the second protrusions protrude towards the first fluid channel, thereby increasing the heat exchange area between the second protrusions and the first fluid to improve the heat exchange effect of the first fluid channel. The second protrusions form second recesses on the side facing the finned plate, increasing the flow space of the second fluid channel and thus reducing the pressure drop in the second fluid channel. Furthermore, second grooves are formed between the second protrusions, and a second flat portion is formed around the second recess on the side of the second groove facing the finned plate. The finned plate contacts at least a portion of the second flat portion, thereby transferring heat from the second plate to the finned plate, increasing the heat exchange area of ​​the second fluid channel and enhancing the heat exchange efficiency inside the second fluid channel.

[0010] This application controls the relationship between the distance a1 between the bottoms of adjacent second recesses and the minimum dimension a2 of the second flat portion along the length of the heat exchanger along the length of the heat exchanger. This reduces the obstruction of the second flat portion to the fluid, thereby enhancing fluid flow between adjacent second recesses and improving heat exchange efficiency at the second recesses. This effectively reduces pressure drop and improves the heat exchanger's performance. Furthermore, when the second fluid flows between adjacent second recesses, it enhances the disturbance and mixing between the second fluid at the second recesses and the second fluid at the finned plate, making heat exchange more uniform. This application reduces the obstruction of the second flat portion to the fluid along the length of the heat exchanger by controlling the relationship between the distance a1 between the bottoms of adjacent second recesses and the minimum dimension a2 of the second flat portion along the length of the heat exchanger. The area of ​​the second flat portion is reduced, thereby decreasing the heat transfer area between the finned plate and the second flat portion. The heat transfer efficiency of the finned plate is balanced to increase the heat transfer at the second recess. Since there is thermal resistance between the finned plate and the second plate, and the heat transfer efficiency at the second recess is high, the heat transfer at the finned plate and the second recess is balanced by controlling the relationship between the distance a1 between the bottoms of adjacent second recesses and the minimum dimension a2 of the second flat portion along the length direction of the heat exchanger between adjacent second recesses. This can maximize the heat transfer effect of the second fluid channel and effectively control the pressure drop, breaking the mutual limitation between heat transfer performance and fluid pressure drop in the prior art. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the heat exchanger structure of this application;

[0012] Figure 2 This is an exploded structural diagram of the first plate, second plate, finned plate and third plate of this application;

[0013] Figure 3 This is a partial structural diagram of a portion of the fin structure of the finned plate in this application;

[0014] Figure 4 This is a three-dimensional schematic diagram of a portion of the fin structure of the finned plate in this application;

[0015] Figure 5 This is a schematic diagram of a partial assembly structure of the heat exchanger of this application;

[0016] Figure 6 This is an enlarged view of a partial assembly structure of the heat exchanger in this application;

[0017] Figure 7 This is a schematic diagram of another partial assembly structure of the heat exchanger in this application;

[0018] Figure 8 This is an enlarged view of another partial assembly structure of the heat exchanger in this application;

[0019] Figure 9 This is a partial structural diagram of the second plate of this application facing the first plate;

[0020] Figure 10 This is a partial structural diagram of the second plate of this application facing the fin plate side;

[0021] Figure 11 This is a schematic diagram showing the contact position distribution between the finned plate and the second plate in this application;

[0022] Figure 12 This is a schematic diagram showing the contact position distribution between the finned plate and the heat exchange plate in the prior art. Detailed Implementation

[0023] refer to Figures 1-10As shown, this application provides a heat exchanger, including at least a first fluid channel 5 and a second fluid channel 6 arranged adjacent to each other. The first fluid channel 5 and the second fluid channel 6 can be multiple alternating fluid channels, or a multi-fluid channel structure such as a third fluid channel can be provided. The first fluid channel 5 and the second fluid channel 6 are not interconnected. The first fluid channel 5 is formed by stacked first plates 1 and second plates 2, and the second fluid channel 6 is formed by stacked second plates 2, third plates 3, and a finned plate 4 located between the second plates 2 and the third plates 3. The second plate 2, finned plate 4, and third plate 3 can be fixed by brazing. Of course, the heat exchanger can also include other plates with structures different from the first plate 1, second plate 2, and third plate 3. The finned plate 4 can have the same structure or multiple finned plates 4 with different structures. The first fluid channel 5 can be formed by plates or fins other than the first and second plates 1. The second fluid channel 6 can be formed by plates and fins other than the second plate 2, third plate 3, and finned plate 4. The first plate 1, second plate 2, third plate 3, and finned plate 4 can all be provided with corner holes for connecting the first fluid or the second fluid. Specifically, the first fluid channel 5 is for the flow of the first fluid, and the second fluid channel 6 is for the flow of the second fluid.

[0024] In some implementations, reference Figure 2 , Figures 5-8 The first plate 1 includes a first substrate 11 and a plurality of first protrusions 12 protruding toward the second plate 2, with a first groove 13 formed between adjacent first protrusions 12. The second plate 2 includes a second substrate 21 and a plurality of second protrusions 22 protruding toward the first plate 1, with a second groove 23 formed between adjacent second protrusions 22. The first protrusions 12 and second protrusions 22 are disposed opposite to each other, and the first grooves 13 and second grooves 23 are disposed opposite to each other. Figure 8 As shown, the contact between the tops of the first protrusion 12 and the second protrusion 22 not only enhances the installation strength between the first plate 1 and the second plate 2, but also allows the first fluid to flow within the channel formed by the first groove 13 and the second groove 23, effectively controlling the flow path of the first fluid.

[0025] Of course, the first protrusion 12 and the second protrusion 22 can be aligned or staggered by a certain distance, so that the top of the first protrusion 121 and the top of the second protrusion 221 are at least partially in contact.

[0026] In addition, when the strength of the first plate 1 and the second plate 2 is sufficient, the tops of the first protrusion 12 and the second protrusion 22 may not contact each other. A predetermined distance is provided between the first protrusion 12 and the second protrusion 22 to allow the first fluid to flow, thereby increasing the uniformity of the heat exchange of the first fluid.

[0027] like Figure 6 As shown, the first protrusion 12 forms a first recess 14 on the side opposite to the second plate, the first groove 13 forms a first flat portion 15 on the side opposite to the second plate, and the second protrusion 22 forms a second recess 24 on the side facing the fin plate 4, as... Figures 6-10 As shown, the second recess 24 includes a recess bottom 241 and a recess side portion 242. The second groove 23 forms a second flat portion 25 surrounding the second recess 24 on the side facing the fin plate 4, as shown. Figure 10 The second flat portion 25 shown includes an arcuate top formed on the back side of the second groove 23 between two adjacent second recesses 24 and a planar portion surrounded by four adjacent second recesses 24. In other embodiments, the second flat portion 25 between two adjacent second recesses 24 can be a planar structure of equal width between adjacent second recesses 24, or a planar structure of unequal width. The finned plate 4 facing the second plate 2 contacts at least a portion of the second flat portion 25. The finned plate 4 exchanges heat through contact with the second flat portion 25 of the second plate 2, thereby transferring heat from the second plate 2 to the finned plate 4 to increase the heat exchange area of ​​the second fluid channel 6, thus enhancing the heat exchange at the center of the second fluid channel 6.

[0028] like Figure 7 , Figure 8 As shown, the finned plate 4 divides the second fluid channel into multiple first sub-channels 61, at least a portion of which are connected to the second recess 24. Along the length of the heat exchanger, i.e., as shown... Figure 1 The left and right directions, such as Figure 8 The left and right directions are shown, as follows Figure 10 In the vertical direction, the distance between the bottom 241 of adjacent second recesses 24 is a1, and the minimum dimension of the second flat portion 25 between adjacent second recesses 24 along the length of the heat exchanger is a2, i.e. Figure 8The minimum distance between the tops of adjacent second recesses 24 along the length of the heat exchanger is shown in the figure. Where a2 ≤ 0.3a1, if a2 > 0.3a1, then along the length of the heat exchanger, the minimum size of the second flat portion 25 between adjacent second recesses 24 is relatively large. The flow resistance of the second fluid at the recess is large, and the second fluid has difficulty crossing the second flat portion 25 to flow between adjacent second recesses 24. Moreover, the second recesses 24 are located near the wall, where the heat exchange efficiency is high. The second fluid cannot flow smoothly here, which affects the heat exchange effect at the second recesses 24. This application controls the relationship between the distance a1 between the bottom 241 of adjacent second recesses 24 and the minimum dimension a2 of the second flat portion 25 between adjacent second recesses 24 along the length of the heat exchanger. This reduces the obstruction of the second flat portion 25 to the fluid, thereby enhancing the flow of fluid between adjacent recesses and improving the heat exchange efficiency at the recesses. This effectively reduces pressure drop and improves the heat exchange effect of the heat exchanger. Furthermore, the finned plate 4 divides the second fluid channel into multiple first sub-channels 61, at least some of which are connected to the second recesses 24. When the second fluid flows at adjacent second recesses 24, it enhances the disturbance and mixing between the second fluid at the second recesses 24 and the second fluid at the finned plate 4. This application reduces the area of ​​the second flat portion 25 to make heat exchange more uniform. By reducing the area of ​​the second flat portion 25, the heat transfer area between the finned plate 4 and the second flat portion 25 is reduced. The heat transfer efficiency of the finned plate 4 is balanced to increase the heat transfer at the recess. Since there is thermal resistance between the finned plate 4 and the second plate 2, and the heat transfer efficiency at the second recess 24 is higher, the heat transfer between the finned plate 4 and the recess is balanced by controlling the relationship between the distance a1 between the bottom 241 of the adjacent second recesses 24 and the minimum dimension a2 of the second flat portion 25 between the adjacent second recesses 24 along the length direction of the heat exchanger. This can maximize the heat transfer effect of the second fluid channel and effectively control the pressure drop, breaking the mutual limitation between heat transfer performance and fluid pressure drop in the prior art.

[0029] Existing technologies primarily focus on increasing the contact area between the finned plate 4 and the second plate 2, thereby transferring more heat to the finned plate 4 to enhance heat exchange in the center of the second fluid channel. They also improve the overall heat exchanger performance by increasing the pressure drop through the disturbance and obstruction of the fluid by adding finned plates 4. Even with protrusions on the second plate 2 pointing towards the first fluid channel 5, the spacing between these protrusions is too large, resulting in excessively large gaps between the recesses formed on the second fluid channel side. This makes it difficult for the second fluid to flow across adjacent recesses, leading to poor fluid flow within the recesses and wasting the high-efficiency heat exchange zone. Furthermore, they fail to effectively reduce the pressure drop. Those skilled in the art have focused on improving the heat exchange effect of the second fluid channel by changing the structure of the finned plate 4, without considering how the structure at the recesses, in conjunction with its relationship to the finned plate 4, can balance the heat exchange at the recesses and enhance the overall heat exchange performance. Heat exchanger technology focuses on balancing heat exchange performance and fluid pressure drop. For applications with high requirements for both heat exchange performance and fluid pressure drop, the main technical means is still to increase the number of fluid channels and the heat exchange area. This not only increases costs but also increases the weight and size of the heat exchanger, introducing some adverse factors to installation and even lifespan.

[0030] In the embodiments provided in this application, such as Figures 9-11 As shown, the second plate 2 is provided with a main heat exchange zone, which has a second recess 24 and a second flat portion 25 distributed thereon. Figure 11 As shown, the contact area between the second flat portion 25 of the main heat exchange zone and the finned plate 4 is s1, as... Figure 11 The sum of the areas of the darker regions shown is s1, and the orthographic projection area of ​​the main heat exchange region in the plane of the second substrate 21 is S, as shown. Figure 11 The entire rectangular area shown is S, where s1 / S≤0.25. Of course, in addition to the main heat exchange area, other locations on the second substrate 21 can also be provided with partial second recesses 24 and second flat portions 25.

[0031] like Figure 12 As shown, in the prior art, the heat exchange plate has elliptical protrusions facing away from the finned plate. These elliptical protrusions form recesses on the side facing the finned plate. The distance between adjacent recesses is roughly equivalent to the dimension of the elliptical protrusions along the length of the heat exchanger. If the distance between adjacent recesses is too large, fluid flow is difficult between them, resulting in poor fluid heat transfer performance at this point. Figure 12 As shown, the darker area s1 represents the contact area between the finned plate and the heat exchange plate. The proportion of the contact area between the finned plate and the heat exchange plate is significantly larger than that shown. Figure 11As shown, the contact area between the finned plates and the heat exchange plates is too large, and the flow of fluid between the finned plates is not smooth, especially the flow between the finned plates and the recesses. This results in excessive pressure drop and poor heat exchange performance. Under the condition that both heat exchange performance and pressure drop requirements are high, the only way to improve heat exchange performance is to increase the volume of the heat exchanger by increasing the number of heat exchange plates.

[0032] In this embodiment, by controlling the contact area s1 between the second flat portion 25 of the main heat exchange zone and the finned plate 4 to satisfy s1 / S≤0.25 with the orthographic projection area S of the main heat exchange zone in the plane of the second substrate 21, the contact area between the finned plate 4 and the second flat portion 25 is reduced. This rationally allocates the proportion of the second flat portion 25 and the second recess 24, thereby distributing the heat exchange between the finned plate 4 and the second recess 24 and improving the heat exchange effect at the second recess 24. Furthermore, the contact area between the finned plate 4 and the second flat portion 25 is controlled within the aforementioned range. Figure 11 As shown, the contact point between the second flat portion and the finned plate is connected to the front, back, left, and right flow areas, facilitating fluid flow between channels to improve the heat transfer uniformity of the second fluid. This also increases the proportion of the second recess 24 and enhances the mixing and turbulence of the second fluid at the second recess 24 with the second fluid near the finned plate 4, rapidly removing heat from the second recess 24 and improving the overall heat transfer effect. Furthermore, the fluid at the second recess 24 mixes with the fluid near the finned plate 4 and flows quickly through the first sub-channel 61 of the finned plate 4, effectively reducing the pressure drop in the second fluid channels. If s1 / S > 0.25, to ensure the contact area between the finned plate 4 and the second flat portion 25, the proportion of the second recess 24 is reduced, failing to effectively utilize the high heat transfer area at the second recess 24, thus failing to effectively improve heat transfer performance. Moreover, if s1 is too large, the second fluid cannot flow smoothly in each of the first sub-channels 61, affecting not only heat transfer uniformity but also failing to effectively reduce the pressure drop.

[0033] In some implementations, such as Figures 3-7As shown, the finned plate 4 includes multiple tops 41, multiple bottoms 42, and fin portions 43 connecting adjacent tops 41 and bottoms 42. A first sub-channel 61 is formed between adjacent fin portions 43. At least a portion of the tops 41 contacts the second flat portion 25 of the second plate 2. Along the length direction of the heat exchanger, the fin portions 43 include first fin portions 431 and second fin portions 432. The first fin portions 431 and second fin portions 432 are staggered along the width direction of the heat exchanger, i.e., in the left-right direction as shown in 4. The second flat portion 25 extends along the length direction of the heat exchanger. Multiple serrated portions are formed on both sides of the second flat portion 25 along the width direction of the heat exchanger. A window 433 is formed between adjacent first fin portions 431 and second fin portions 432. The window 433 communicates with the second recess 24. The fins 43 of the finned plate 4 extend along the flow direction of the second fluid, reducing the resistance of the finned plate 4 to the second fluid. This allows the second fluid to flow smoothly through the first sub-channels 61 between the fins 43, quickly carrying away the second fluid from the second recess 24, thereby improving the heat exchange efficiency at the second recess 24 and effectively reducing the pressure drop in the second fluid channel. Furthermore, the staggered arrangement of multiple first fins 431 and second fins 432 enhances the turbulence of the second fluid at each first sub-channel 61, improving the heat exchange effect at the finned plate 4. The windows 433 of the finned plate 4 communicate with the second recess 24, allowing the second fluid at the second recess 24 to flow smoothly to the first sub-channels 61 and mix thoroughly with the second fluid at the finned plate 4. Of course, the finned plate 4 can also be installed by rotating it at a certain angle, such as 90°.

[0034] In other implementations, such as Figure 6 As shown, along the width direction of the heat exchanger, the finned plate 4 has a periodically distributed top, finned portion, bottom, and finned portion. The second plate 2 has a periodically distributed second recess 24 and second flat portion 25 on the side facing the finned plate 4. There are no more than two tops that do not contact the second flat portion 25 between adjacent tops that at least partially contact the second flat portion 25. Since the period of the finned portion of the finned plate 4 and the period of the second recess 24 of the second plate 2 can be different, the uniformity of fluid flow and the heat exchange efficiency of the finned plate 4 can be adjusted by controlling the contact ratio between the top of the finned plate 4 and the second flat portion 25, thereby balancing the heat exchange efficiency at the second recess 24 and the finned plate 4, and thus maximizing the overall heat exchange performance of the heat exchanger. Of course, along the width direction of the heat exchanger, the top of the finned plate 4 can be in contact with the second flat portion 25, thereby improving the heat exchange efficiency at the finned plate 4.

[0035] In some implementations, such as Figure 7 As shown, along the width direction of the heat exchanger, i.e. Figure 7In the left-right direction shown, the maximum width of the second recess 24 is b1, which is the distance between the tops of the second recess 24, and the width of the top of the fin plate 4 is c1, which is the width of the straight section at the top of the fin plate 4. Here, b1 is not less than c1, ensuring that the top 41 of the fin plate 4 will not block the second recess 24. Especially when the period of the fin portion 43 of the fin plate 4 is different from the period of the second recess 24, it ensures that the second recess 24 is connected to the first sub-channel 61 at the fin plate 4. Moreover, when the front and back structures of the fin plate 4 are the same, by controlling the width of the top 41 of the fin plate 4, the flow resistance at the second recess 24 and the fin plate 4 can be balanced, maximizing the overall heat exchange effect.

[0036] The second plate 2 has multiple second flat portions 25 located on the first plane, and the fin plate 4 has multiple tops 41 located on the second plane. The first plane and the second plane are parallel. In the direction perpendicular to the first plane, the depth of the second recess 24 is less than the height of the fin plate 4. By controlling the relationship between the depth of the second recess 24 and the height of the fin plate 4, the heat exchange area at the fin plate 4 is guaranteed. In addition, the pressure drop of the second fluid channel is reduced by the first sub-channel 61 at the fin plate 4, which allows for smooth flow. The pressure drop at the second recess 24 is also reduced, thereby improving the heat exchange effect while effectively controlling the pressure drop.

[0037] In some specific embodiments, the depths of the multiple second recesses 24 may be different, and the heights of the multiple first protrusions 12 and second protrusions 22 may be staggered to improve the structural reliability of the heat exchanger and ensure that at least some of the first protrusions 12 and second protrusions 22 are in contact.

[0038] In some specific embodiments, the recess side 242 of the second recess 24 includes a plurality of inclined surfaces that gradually taper from the second flat portion 25 to the bottom 241 of the recess, or the recess side 242 of the second recess 24 is a curved surface that tapers from the second flat portion 25 to the bottom 241 of the recess. By controlling the recess side 242 of the second recess 24 to have a structure that tapers from the second flat portion 25 to the bottom 241 of the recess, the flow difference between the central region and the near-wall region of the first fluid channel 5 is established, the heat transfer from the near-wall region to the central region is enhanced, and the heat exchange performance of the first fluid channel 5 is further improved.

[0039] Furthermore, such as Figure 8As shown, the first protrusion 12 includes a first protrusion top 121 and a first protrusion side 122, and the second protrusion 22 includes a second protrusion top 221 and a second protrusion side 222. The first protrusion top 121 and the second protrusion top 221 are at least partially in contact. The first protrusion side 122 contracts from the first groove 13 toward the first protrusion top 121, and the second protrusion side 222 contracts from the second groove 23 toward the second protrusion top 221. This results in the second sub-channel 51 surrounded by the first groove 13 and the second groove 23 having a cross-section that is large in the middle and small at both ends, further enhancing the heat transfer from the near-avoidance area to the central area and improving the heat exchange performance of the first fluid channel 5.

[0040] like Figures 5-8 As shown, the first protrusion 12 is similar to a quadrangular pyramid, and four first grooves 13 are arranged around the first protrusion 12. Adjacent first grooves 13 intersect, and the extension direction of each first groove 13 is staggered with the length direction of the heat exchanger. The first sub-channel 61 extends along the length direction of the heat exchanger, and the extension direction of the first sub-channel 61 is set at an angle with the extension direction of the first groove 13, so that the adjacent first grooves 13 are set at an angle, making the first flat part 15 form a rhombus. The first fluid flows in the staggered second sub-channels 51, which improves the turbulence of the first fluid and extends the flow path of the first fluid, thereby improving the heat exchange effect of the first fluid. The second fluid extends along the length direction of the heat exchanger, which reduces the pressure drop of the second fluid. The staggered arrangement of the second sub-channels 51 and the first sub-channels 61 makes the heat exchange more uniform.

[0041] like Figure 7 , Figure 8As shown, the third plate 3 includes a third substrate 31 and a third protrusion 32 protruding away from the fin plate 4. A third groove 33 is formed between adjacent third protrusions 32. A third recess 34 is formed on the side of the third protrusion 32 facing the fin plate 4. A third flat portion is formed around the third recess 34 on the side of the third groove 33 facing the fin plate 4. The fin plate 4 facing the third plate 3 contacts at least a portion of the third flat portion. In the second fluid channel, the top 41 of the fin plate 4 contacts the second flat portion 25 of the second plate 2, and the bottom 42 of the fin plate 4 contacts the third flat portion of the third plate 3. A plurality of first sub-channels 61 are formed between the fin plates 4. The second recess 24 is located above the top 41 of the finned plate 4, and the third recess 34 of the third plate 3 is located below the bottom 42 of the finned plate 4. The second recess 24 and the third recess 34 are connected to the first sub-channel 61. Therefore, the second fluid channel not only improves the heat transfer performance and reduces the pressure drop through the second recess 24, but also further improves the heat transfer performance and reduces the pressure drop through the third recess 34 of the third plate. By setting the third plate 3 to have the same structure as the first plate 1, the entire heat exchanger maintains a sequential repeating arrangement of first plate 1, second plate 2, finned plate, first plate 1, second plate 2, finned plate 4, simplifying the structure of the heat exchanger. Of course, the third plate 3 can also adopt a different structure from the first plate 1, for example, as shown in the figure. Figure 5 , Figure 6 The planar structure shown.

[0042] The heat exchanger provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A heat exchanger, comprising at least a first fluid channel and a second fluid channel arranged adjacent to each other, wherein the first fluid channel is formed by at least a first plate and a second plate stacked together, and the second fluid channel is formed by at least a second plate, a third plate, and a finned plate located between the second plate and the third plate stacked together, characterized in that, The first plate includes a first substrate and a plurality of first protrusions protruding toward the second plate, with a first groove formed between adjacent first protrusions; the second plate includes a second substrate and a plurality of second protrusions protruding toward the first plate, with a second groove formed between adjacent second protrusions; the first protrusions and the second protrusions are disposed opposite to each other. The second protrusion forms a second recess on the side facing the fin plate, the second recess including a bottom and a side portion of the recess, and the second groove forms a second flat portion surrounding the second recess on the side facing the fin plate, and the fin plate facing the second plate contacts at least a portion of the second flat portion. The finned plate divides the second fluid channel into a plurality of first sub-channels. At least a portion of the first sub-channels are in communication with the second recess. Along the length of the heat exchanger, the distance between the bottoms of adjacent second recesses is a1, and the minimum dimension of the second flat portion between adjacent second recesses along the length of the heat exchanger is a2, wherein a2≤0.3a1.

2. The heat exchanger according to claim 1, characterized in that, The second plate is provided with a main heat exchange area, which is distributed with a second recess and a second flat portion. The contact area between the second flat portion and the fin plate is s1, and the orthographic projection area of ​​the main heat exchange area in the plane of the second substrate is S, wherein s1 / S≤0.

25.

3. The heat exchanger according to claim 2, characterized in that, The finned plate includes multiple tops, multiple bottoms, and fin portions connecting adjacent tops and bottoms, with a first sub-channel formed between adjacent fin portions, and at least a portion of the tops contacting a second flat portion of the second plate.

4. The heat exchanger according to claim 3, characterized in that, Along the length of the heat exchanger, the fin portion includes a first fin portion and a second fin portion. The first fin portion and the second fin portion are staggered along the width of the heat exchanger, and a window is formed between adjacent first fin portions and second fin portions. The window communicates with the second recess.

5. The heat exchanger according to claim 3, characterized in that, Along the width direction of the heat exchanger, the top of each of the finned plates is in contact with the second flat portion; or, Along the width direction of the heat exchanger, there are no more than two tops that do not contact the second flat portion between adjacent tops that are at least partially in contact with the second flat portion.

6. The heat exchanger according to claim 1, characterized in that, The second recess has a recessed side portion comprising a plurality of sloping surfaces that gradually taper from the second flat portion toward the bottom of the recess; or, The second pit has a side portion that is a curved surface that tapers from the second flat portion toward the bottom of the pit.

7. The heat exchanger according to any one of claims 3-5, characterized in that, Along the width direction of the heat exchanger, the maximum width of the second recess is b1, and the width of the top of the finned plate is c1, wherein b1 is not less than c1; and / or, The second plate has a plurality of second flat portions located on a first plane, and the fin plate has a plurality of top portions located on a second plane. The first plane is parallel to the second plane, and in a direction perpendicular to the first plane, the depth of the second recess is less than the height of the fin plate.

8. The heat exchanger according to any one of claims 1-6, characterized in that, The third plate includes a third substrate and a third protrusion protruding away from the fin plate. A third groove is formed between adjacent third protrusions. A third pit is formed on the side of the third protrusion facing the fin plate. A third flat portion is formed around the third pit on the side of the third groove facing the fin plate. The fin plate facing the third plate contacts at least a portion of the third flat portion.

9. The heat exchanger according to any one of claims 1-6, characterized in that, The first protrusion includes a first protrusion top and a first protrusion side, and the second protrusion includes a second protrusion top and a second protrusion side. The first protrusion top and the second protrusion top are at least partially in contact. The first protrusion side contracts from the first groove toward the first protrusion top, and the second protrusion side contracts from the second groove toward the second protrusion top.

10. The heat exchanger according to claim 9, characterized in that, A plurality of first grooves are provided around the first protrusion, adjacent first grooves intersect, and the extension direction of the first sub-channel is set at an angle to the extension direction of the first groove.

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