A printed plate heat exchanger with coupled biomimetic fins and plate fins

Abstract

This invention discloses a printed plate heat exchanger with a biomimetic finned and plate-fin structure coupling, comprising a heat exchange core; the heat exchange core includes alternating hot fluid channels and cold fluid channels; the hot fluid channels are printed plate heat exchange structures with biomimetic tadpole-shaped fins, and the cold fluid channels are plate-fin heat exchange structures. The heat exchange structure of plate-fin and printed plate coupled in this invention can effectively achieve efficient heat transfer between hot and cold working fluids with large specific heat capacity differences. The biomimetic tadpole-shaped fins of this invention can reduce the dead zone of hot fluid flow and lower flow resistance. The corrugated fin plate of this invention can achieve continuous disruption of the cold fluid boundary layer, thereby enhancing the heat transfer performance of the cold fluid. This improves the overall heat exchange efficiency of the heat exchanger.

Description

Technical Field

[0001] This invention relates to the field of heat exchange device technology, specifically to a printed plate heat exchanger that couples biomimetic fins and plate-fin structures. Background Technology

[0002] Transcritical carbon dioxide refrigeration systems have seen rapid development in the automotive air conditioning field, where the performance and design of the heat exchanger significantly impact the overall cycle efficiency. Printed plate heat exchangers (PPGs) are widely used in carbon dioxide-based refrigeration systems due to their ability to withstand high temperatures and pressures, along with their excellent compactness and heat exchange performance. Traditional PPGs have the same heat exchange area on both the hot and cold sides, making them suitable for heat exchange processes between working fluids with similar specific heat capacities, resulting in high overall heat exchange efficiency, such as when used as regenerators. However, when used as coolers in transcritical carbon dioxide refrigeration systems, PPGs have the following drawbacks:

[0003] 1) In a gas cooler, the hot-side working fluid is CO2 and the cold-side working fluid is air. The specific heat capacity of the two differs by tens or hundreds of times, resulting in low heat exchange efficiency of the printed plate heat exchanger and a large required heat exchanger volume and mass.

[0004] 2) The traditional printed plate heat exchanger channel fin structure has a flow dead zone, which will lead to a large pressure loss.

[0005] Patent application CN114111393A discloses a heat exchanger based on a supercritical working fluid, including a heat exchange plate, core, and printed circuit board. This application employs airfoil fins with moderate heat exchange performance in regions with low fluid temperature, high density, low flow rate, and slow and uniform changes in physical properties, maintaining high heat exchange capacity and low pressure drop. However, it still does not solve the aforementioned problems. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a printed plate heat exchanger that couples biomimetic fins and plate-fin structure, so as to be suitable for heat exchange problems between working fluids with large differences in physical properties, and to overcome the disadvantages of existing printed plate heat exchangers with large flow dead zones and high flow resistance.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] A printed plate heat exchanger coupled with biomimetic fins and plate-fin structures includes a heat exchange core; the heat exchange core includes alternating hot fluid channels and cold fluid channels; the hot fluid channels are printed plate heat exchange structures with biomimetic tadpole-shaped fins, and the cold fluid channels are plate-fin heat exchange structures.

[0009] Advantages: The printed plate heat exchanger of this invention forms a structure with low fluid flow resistance by incorporating biomimetic tadpole-shaped fins in the hot fluid channel. Extracting features from the tadpole's morphology reveals that the head of the biomimetic fin is elliptical to reduce fluid pressure loss. The tail of the biomimetic fin is a narrow, elongated triangle that deforms according to the pressure difference between the two sides of the fluid, reducing the dead zone and thus decreasing the flow resistance of the printed plate heat exchanger. Therefore, it overcomes the shortcomings of existing printed plate heat exchangers, which have large dead zones and high flow resistance.

[0010] Preferably, the printed plate heat exchanger further includes a cold fluid inlet housing, a cold fluid outlet housing, a cold fluid inlet flange, a cold fluid outlet flange, a hot fluid inlet housing, a hot fluid outlet housing, a hot fluid inlet pipe, and a hot fluid outlet pipe.

[0011] The cold fluid inlet box and the cold fluid outlet box are respectively installed on the front and rear sides of the heat exchange core, and the cold fluid inlet box and the cold fluid outlet box are connected to the cold fluid channel of the heat exchange core; the cold fluid inlet flange is installed at the inlet of the cold fluid inlet box, and the cold fluid outlet flange is installed at the outlet of the cold fluid outlet box.

[0012] The hot fluid inlet box and the hot fluid outlet box are respectively installed on the left and right sides of the heat exchange core, and the hot fluid inlet box and the hot fluid outlet box are connected to the hot fluid channel of the heat exchange core; the hot fluid inlet pipe is installed at the inlet of the hot fluid inlet box and the hot fluid outlet box is installed at the outlet of the hot fluid outlet box.

[0013] Preferably, the biomimetic tadpole-shaped wing has a connected head structure and a tail structure, wherein the head structure is elliptical and the tail structure is a pointed structure.

[0014] Preferably, a flexible tail structure made of flexible metal material is further provided behind the tail structure, and the flexible tail structure is in the shape of a narrow triangle.

[0015] Preferably, the cold fluid channel includes fins, and the fins include two stacked corrugated plates; the corrugated plates have a concave point P1 and a convex point P2, the two corrugated plates are fixed at the concave point P1 position, and the convex point P2 position of the corrugated plates is fixed to the partition.

[0016] Preferably, the waveform of the corrugated plate is a sine and cosine function waveform, and the corresponding positions of the two corrugated plates differ by one cycle.

[0017] Preferably, the center of the biomimetic tadpole-shaped fin is the elliptical center O1 of the head structure, and the elliptical center O1 of the biomimetic tadpole-shaped fin is at the same horizontal position as the protrusion P2 of the cold fluid channel.

[0018] Preferably, the inlet cross-sectional area of ​​the cold fluid channel is larger than the inlet cross-sectional area of ​​the hot fluid channel.

[0019] Preferably, the ratio of the inlet cross-sectional area of ​​the hot fluid channel to the inlet cross-sectional area of ​​the cold fluid channel is determined by the difference in specific heat capacity between the hot fluid and the cold fluid.

[0020] Preferably, the hot fluid channel and the cold fluid channel are formed by brazing with a partition.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] (1) Reducing the dead zone of the printed plate heat exchanger structure and reducing flow resistance. The "bionic tadpole-shaped" fin structure of the hot fluid channel described in this invention is based on the long-term flowing habits of tadpoles in water. Through long-term evolution, it has formed a morphological structure with low fluid flow resistance. Extracting the morphological features of the tadpole, it can be found that the head structure of the bionic fin is elliptical to reduce the pressure loss of the fluid. The flexible tail structure of the bionic fin is a narrow triangle, which can deform with the pressure difference of the fluid on both sides to reduce the dead zone of the fluid flow, thereby reducing the flow resistance of the printed plate heat exchanger structure.

[0023] (2) Increase three-dimensional turbulence to enhance the heat transfer performance of the plate-fin heat exchanger structure. The cold fluid three-dimensional concave-convex wave plate-shaped fins described in this invention are welded at the concave-convex points. When the fluid flows in the cold fluid channel, it is blocked by the concave-convex weld points and affected by the change in the cross-sectional shape of the flow channel, generating secondary flow. During the flow process, the boundary layer of the cold fluid continuously forms and breaks down, undergoes slight compression and expansion, and rotates within the concave-convex grooves of the plate, forming secondary vortex flow. Ultimately, this achieves the effect of enhancing the heat transfer performance of the plate-fin heat exchanger structure.

[0024] (3) Achieving efficient heat transfer between working fluids with large specific heat capacity differences. The novel printed plate heat exchanger structure described in this invention, which couples a plate-fin heat exchanger structure with a printed plate heat exchanger structure, has a larger windward area for the low specific heat capacity cold fluid than for the high specific heat capacity hot fluid. This results in a larger channel volume on the cold fluid side than on the hot fluid side, and a larger inlet channel diameter for the cold fluid than for the hot fluid, ultimately effectively increasing the inlet mass flow rate of the low specific heat capacity fluid. This effectively achieves efficient heat transfer between working fluids with large specific heat capacity differences. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0026] Figure 2This is a schematic diagram of the internal partial structure of the heat exchange core according to an embodiment of the present invention;

[0027] Figure 3 This is a three-dimensional partial cross-sectional view of the printed plate heat exchanger structure of the heat exchanger core according to an embodiment of the present invention.

[0028] Figure 4 This is a top view of the printed plate heat exchanger structure of the heat exchanger core according to an embodiment of the present invention;

[0029] Figure 5 This is a three-dimensional partial cross-sectional view of the plate-fin heat exchanger structure of the heat exchanger core in an embodiment of the present invention.

[0030] Figure 6 This is a three-dimensional structural diagram of the fins of the plate-fin heat exchanger structure of the heat exchanger core in an embodiment of the present invention.

[0031] In the diagram: 1. Heat exchange core; 2. Cold fluid inlet box; 3. Cold fluid outlet box; 4. Cold fluid inlet flange; 5. Cold fluid outlet flange; 6. Hot fluid inlet box; 7. Hot fluid outlet box; 8. Hot fluid inlet pipe; 9. Hot fluid outlet pipe; 11. Hot fluid channel; 110. Bionic tadpole-shaped fins; 111. Head structure; 112. Tail structure; 113. Tail flexible structure; 12. Cold fluid channel; 121. Fins. Detailed Implementation

[0032] To facilitate understanding of the technical solution of the present invention by those skilled in the art, the technical solution of the present invention will now be further described in conjunction with the accompanying drawings.

[0033] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0034] See Figure 1 This embodiment discloses a printed plate heat exchanger that couples biomimetic fins and plate-fin structures, including a heat exchange core 1, a cold fluid inlet box 2, a cold fluid outlet box 3, a cold fluid inlet flange 4, a cold fluid outlet flange 5, a hot fluid inlet box 6, a hot fluid outlet box 7, a hot fluid inlet pipe 8, and a hot fluid outlet pipe 9.

[0035] The heat exchange core 1 includes alternating hot fluid channels 11 and cold fluid channels 12. The hot fluid channels 11 are printed plate heat exchange structures with biomimetic tadpole-shaped fins 110, and the cold fluid channels 12 are plate-fin heat exchange structures. Cold fluid inlet housing 2 and cold fluid outlet housing 3 are respectively installed on opposite front and rear sides of the heat exchange core 1, and are connected to the cold fluid channels 12 of the heat exchange core 1. A cold fluid inlet flange 4 is installed at the inlet of the cold fluid inlet housing 2, and a cold fluid outlet flange 5 is installed at the outlet of the cold fluid outlet housing 3. A hot fluid inlet housing 6 and a hot fluid outlet housing 7 are respectively installed on opposite left and right sides of the heat exchange core 1, and are connected to the hot fluid channels 11 of the heat exchange core 1. A hot fluid inlet pipe 8 is installed at the inlet of the hot fluid inlet housing 6, and at the outlet of the hot fluid outlet housing 7. The hot fluid channel 11 flows from A1 through the hot fluid inlet pipe 8, the hot fluid inlet box 6, the heat exchange core 1, the hot fluid outlet box 7, and the hot fluid outlet pipe 9, and then flows out from A2. The cold fluid channel 12 flows from B1 through the cold fluid inlet flange 4, the cold fluid inlet box 2, the heat exchange core 1, the cold fluid outlet box 3, and the cold fluid outlet flange 5, and then flows out from B2.

[0036] The printed plate heat exchanger of this embodiment achieves a structure with low fluid flow resistance by incorporating biomimetic tadpole-shaped fins in the hot fluid channel 11. Extracting features from the tadpole's morphology reveals that the head structure 111 of the biomimetic tadpole-shaped fins 110 is elliptical to reduce fluid pressure loss. The tail of the biomimetic tadpole-shaped fins 110 is a long, narrow triangle that deforms according to the pressure difference between the two sides of the fluid, reducing the dead zone and thus decreasing the flow resistance of the printed plate heat exchanger structure. Therefore, it overcomes the shortcomings of existing printed plate heat exchangers, such as large dead zones and high flow resistance.

[0037] See Figure 2In this embodiment, a low specific heat capacity working fluid flows through the cold fluid channel 12, while the hot fluid channel 11 contains a high specific heat capacity working fluid. The actual inlet cross-sectional area of ​​the cold fluid channel 12 is larger than that of the hot fluid channel 11. The ratio between the inlet cross-sectional areas of the hot fluid channel 11 and the cold fluid inlet cross-sectional area is determined by the difference in specific heat capacity between the hot and cold fluids. Specifically, when the specific heat capacity difference between the cold and hot fluids is large, the inlet cross-sectional area of ​​the cold fluid channel 12 increases. This embodiment achieves efficient heat exchange between working fluids with large specific heat capacity differences, where the cross-sectional area of ​​the low specific heat capacity cold fluid is larger than that of the high specific heat capacity hot fluid, the channel volume on the cold fluid side is larger than that on the hot fluid side, and the inlet diameter of the cold fluid channel is larger than that of the hot fluid channel, ultimately effectively increasing the inlet mass flow rate of the low specific heat capacity fluid. This achieves efficient heat transfer between working fluids with large specific heat capacity differences.

[0038] See Figure 3 and Figure 4 In this embodiment, the hot fluid channel 11 is a printed circuit board structure containing discontinuous biomimetic tadpole-shaped fins 110. These fins are arranged in alternating triangular patterns and distributed periodically. Each tadpole-shaped fin 110 has a connected head structure 111 and a tail structure 112. The head structure 111 is elliptical, and the tail structure 112 has a pointed shape. A flexible tail structure 113, made of flexible metal material, is located behind the tail structure 112. This flexible tail structure 113 is a narrow, elongated triangle. The center of the biomimetic tadpole-shaped fin 110 is an elliptical center O1. The biomimetic tadpole-shaped fin 110 is based on the long-term flowing habits of tadpoles in water, evolving over time to form a morphological structure with low fluid flow resistance. Extracting features from the tadpole's morphological structure reveals that the head structure 111 of the biomimetic tadpole-shaped fin 110 is elliptical to reduce fluid pressure loss. The tail flexible structure 113 of the biomimetic tadpole-shaped fin 110 is a narrow triangle and can deform according to the pressure difference of the fluid on both sides to reduce the dead zone of the fluid flow, thereby reducing the flow resistance of the printed plate heat exchange structure.

[0039] In this embodiment, the head structure 111 of the biomimetic tadpole-shaped fin 110 is made of hard metal, while the tail flexible structure 113 is made of flexible metal and a high-temperature and pressure-resistant polymer material. When the pressure difference between the fluids on both sides exceeds a certain threshold, the tail flexible structure 113 deforms to balance the fluid pressures on both sides, thereby reducing the dead zone in fluid flow. The biomimetic tadpole-shaped fin 110 is fixed in shape by the head structure 111, while the shape of the tail flexible structure 113 deforms according to the pressure difference of the fluid flow on both sides. This can change the direction of fluid flow, turbulence, and enhance heat transfer performance.

[0040] See Figure 5 and Figure 6 In this embodiment, the cold fluid channel 12 includes a partition and fins 121. The fins 121 include two stacked corrugated plates; each corrugated plate has a concave point P1 and a convex point P2. The two corrugated plates are fixed at the concave point P1, and the convex point P2 is fixed to the partition. The two corrugated plates are brazed together at the concave point P1, and the corrugated plates are brazed to the partition at the convex point P2. The hot fluid channel 11 and the cold fluid channel 12 are brazed together with the partition. When fluid flows in the fins 121, it is diverted at the concave point P1 and flows from both sides.

[0041] In this embodiment, the three-dimensional concave-convex corrugated plate-shaped fins 121 for cold fluid are welded at the concave and convex points. When the fluid flows in the cold fluid channel 12, it is blocked by the concave and convex weld points and affected by the change in the cross-sectional shape of the flow channel, generating secondary flow. During the flow process, the boundary layer of the cold fluid is continuously formed and broken apart, and undergoes slight compression and expansion, rotating within the concave and convex grooves of the plate to form secondary vortex flow. Ultimately, this achieves the effect of enhancing the heat transfer performance of the plate-fin heat exchange structure.

[0042] In some embodiments, the waveform of the corrugated plate is a sine and cosine function waveform, with corresponding positions of two corrugated plates differing by one cycle. For example, adjacent profiles L1 and L2 differ by one cycle. When the difference in specific heat capacity between the hot and cold fluids is greater, the amplitude of the corrugated sine and cosine function is set to be larger, thereby increasing the inlet cross-sectional height of the cold fluid and the inlet mass flow rate; the period of the corrugated sine and cosine function is set to be smaller, thereby increasing the number of weld points between the corrugations, increasing the disturbance and boundary layer disruption experienced by the cold fluid during flow, and thus enhancing the heat transfer performance. Therefore, the heat transfer mismatch problem caused by the difference in specific heat capacity on both sides can be improved accordingly.

[0043] In some embodiments, the elliptical center O1 of the biomimetic tadpole-shaped fins 110 is at the same horizontal position as the protrusion P2 of the cold fluid channel 12. This strengthens the channel and improves the safety and reliability of the heat exchanger.

[0044] In this embodiment, the heat exchange core 1 has alternating cold fluid channels 12 and hot fluid channels 11. The hot fluid channel 11 has a printed circuit board heat exchange structure, while the cold fluid channel 12 has a plate-fin heat exchange structure, and the two are connected by welding. The hot fluid channel 11 has biomimetic tadpole-shaped fins 110. The head structure 111 of the biomimetic tadpole-shaped fins 110 is an elliptical metal structure, and the tail structure 112 is a triangular flexible structure. The plate-fin heat exchange structure of the cold fluid channel 12 consists of baffles and fins 121. The fins 121 are formed by welding two corrugated plates at concave point P1 and convex point P2. The high specific heat capacity working fluid flows in the hot fluid channel 11, and the low specific heat capacity working fluid flows in the cold fluid channel 12. Based on the difference between the high specific heat capacity working fluid and the low specific heat capacity working fluid, a heat exchange structure that couples the plate-fin and printed circuit board structures is designed to effectively achieve efficient heat transfer between hot and cold working fluids with large specific heat capacity differences. Meanwhile, the designed biomimetic tadpole-shaped fins 110 can reduce the dead zone of hot fluid flow and lower flow resistance. The designed corrugated plates and fins 121 can achieve continuous disruption of the boundary layer of cold fluid, thereby enhancing the heat transfer performance of cold fluid.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0046] The above embodiments are merely examples of implementation methods of the invention. The scope of protection of the present invention is not limited to the above embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A printed plate heat exchanger of a bionic fin and plate fin coupled structure, characterized in that: The system includes a heat exchange core (1); the heat exchange core (1) includes alternating hot fluid channels (11) and cold fluid channels (12); the hot fluid channels (11) are printed plate heat exchange structures with biomimetic tadpole-shaped fins (110), and the cold fluid channels (12) are plate-fin heat exchange structures; the biomimetic tadpole-shaped fins (110) have connected head structures (111) and tail structures (112), the head structures (111) are elliptical, and the tail structures (112) are pointed; a flexible tail structure (113) made of flexible metal material is also provided after the tail structure (112), and the flexible tail structure (113) is a narrow triangle.

2. The printed plate heat exchanger with biomimetic fins and plate-fin structure coupled according to claim 1, characterized in that: The printed plate heat exchanger also includes a cold fluid inlet box (2), a cold fluid outlet box (3), a cold fluid inlet flange (4), a cold fluid outlet flange (5), a hot fluid inlet box (6), a hot fluid outlet box (7), a hot fluid inlet pipe (8), and a hot fluid outlet pipe (9). The cold fluid inlet box (2) and the cold fluid outlet box (3) are respectively installed on the front and rear sides of the heat exchange core (1), and the cold fluid inlet box (2) and the cold fluid outlet box (3) are connected to the cold fluid channel (12) of the heat exchange core (1); the cold fluid inlet flange (4) is installed at the inlet of the cold fluid inlet box (2), and the cold fluid outlet flange (5) is installed at the outlet of the cold fluid outlet box (3); The hot fluid inlet box (6) and the hot fluid outlet box (7) are respectively installed on the left and right sides of the heat exchange core (1). The hot fluid inlet box (6) and the hot fluid outlet box (7) are connected to the hot fluid channel (11) of the heat exchange core (1). The hot fluid inlet pipe (8) is installed at the inlet of the hot fluid inlet box (6), and the hot fluid outlet pipe (9) is installed at the outlet of the hot fluid outlet box (7).

3. The printed plate heat exchanger with biomimetic fins and plate-fin structure coupled according to claim 1, characterized in that: The cold fluid channel (12) includes a partition and fins (121). The fins (121) include two stacked corrugated plates. The corrugated plates have a concave point (P1) and a convex point (P2). The two corrugated plates are fixed at the concave point (P1) and the convex point (P2) of the corrugated plates is fixed to the partition.

4. The printed plate heat exchanger with biomimetic fins and plate-fin structure coupled according to claim 3, characterized in that: The waveform of the corrugated plate is a sine and cosine function waveform.

5. The printed plate heat exchanger with biomimetic fins and plate-fin structure coupled according to claim 3, characterized in that: The hot fluid channel (11) and the cold fluid channel (12) are formed by brazing with a partition.

6. The printed plate heat exchanger with biomimetic fins and plate-fin structure coupled according to claim 3, characterized in that: The center of the biomimetic tadpole-shaped fin (110) is the elliptical center (O1) of the head structure (111), and the elliptical center (O1) of the biomimetic tadpole-shaped fin (110) and the protrusion (P2) of the cold fluid channel (12) are at the same horizontal position.

7. The printed plate heat exchanger with biomimetic fins and plate-fin structure coupled according to claim 1, characterized in that: The inlet cross-sectional area of ​​the cold fluid channel (12) is larger than that of the inlet cross-sectional area of ​​the hot fluid channel (11).

8. The printed plate heat exchanger with biomimetic fins and plate-fin structure coupled according to claim 7, characterized in that: The ratio of the inlet cross-sectional area of ​​the hot fluid channel (11) to the inlet cross-sectional area of ​​the cold fluid channel (12) is determined by the difference in specific heat capacity between the hot fluid and the cold fluid.

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