Heterogeneous material heat exchanger structure

Abstract

The utility model discloses a heat exchanger structure made of dissimilar materials, which relates to the technical field of heat exchangers and comprises a top plate, a partition plate, a runner layer and a bottom plate, a plurality of diversion ports are symmetrically arranged on the runner layer, the diversion ports on the same side are communicated through a diffusion groove, and a first heat exchange mechanism and a second heat exchange mechanism which are perpendicular to each other are respectively arranged on two sides of the runner layer. The first heat exchange mechanism and the second heat exchange mechanism comprise flow dividing grooves communicating with the corresponding flow dividing openings, one end of each flow dividing groove communicates with a flow mixing groove, a flow blocking groove is formed in the position, located between the two flow mixing grooves, of the first heat exchange mechanism, and a plurality of flow blocking pieces are installed in the flow blocking groove. The problems of low heat exchange efficiency and non-uniform heat exchange in the prior art are solved, the first heat exchange mechanism and the second heat exchange mechanism are arranged on the two sides of the runner layer, the heat dissipation area is increased, the heat exchange efficiency is improved, eddy current can be generated when media flow through the arc-shaped spoilers, the flow speed of the media on the middle side is slowed down, and the heat exchange efficiency is improved. And heat exchange is uniform.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger technology, specifically to a heat exchanger structure made of dissimilar materials. Background Technology

[0002] A heat exchanger is an energy-saving device that facilitates heat transfer between two or more fluids at different temperatures. It transfers heat from a higher-temperature fluid to a lower-temperature fluid, bringing the fluid temperature to the specified parameters to meet process requirements. It is also a key component for improving energy efficiency. Heat exchangers can be classified by structure as: floating head heat exchangers, fixed tube sheet heat exchangers, U-tube sheet heat exchangers, and plate heat exchangers. Plate heat exchangers are characterized by high heat transfer efficiency, low resistance coefficient, and compact structure. Their heat exchange channels are formed by stacking numerous plates of the same shape, enabling heat exchange between cold and hot fluids within the channels. Vacuum brazing is a mature welding technology commonly used in the industry for plate heat exchangers.

[0003] Publication No. CN118224904B discloses an aluminum alloy multilayer heat exchanger device and its manufacturing method, including a top plate, a partition plate attached to the bottom surface of the top plate, a plurality of flow channel layers attached to the bottom of the partition plate, and a bottom plate attached to the bottom of the flow channel layers. The heat exchange efficiency is improved by the staggered arrangement of the flow channel layers and the increase of cold flow and hot flow splits for the medium flow.

[0004] However, the medium flow channel of the flow channel layer is set on one side. When the two flow channel layers are attached, the smooth surface of one flow channel layer is attached to the medium flow channel of the other flow channel layer, which reduces the heat dissipation efficiency. The medium flow channel structure of the flow channel layers is the same. The medium flow channel in the middle is short, and the medium can easily flow through the medium flow channel in the middle. When the medium flows out, it cannot fully exchange heat. The heat exchange efficiency on the middle side is low, while the heat exchange efficiency on both sides is high, which makes the heat exchange not uniform enough. Utility Model Content

[0005] The purpose of this invention is to provide a heat exchanger structure made of dissimilar materials to solve the aforementioned defects caused by the prior art.

[0006] A heat exchanger structure made of dissimilar materials includes a top plate, a partition plate attached to the bottom side of the top plate, and a plurality of sequentially stacked flow channel layers attached to the bottom side of the partition plate. A bottom plate is attached to one side of the flow channel layers on the bottom side. A plurality of flow outlets are symmetrically arranged on the flow channel layers. The flow outlets on the same side are connected by a diffusion groove. A first heat exchange mechanism and a second heat exchange mechanism perpendicular to each other are respectively arranged on both sides of the flow channel layers. The second heat exchange mechanism is symmetrically arranged on both sides of the first heat exchange mechanism. The first heat exchange mechanism and the second heat exchange mechanism include flow channel communicating with the corresponding flow outlet. One end of the flow channel is connected to a mixing channel. A plurality of flow channels are connected between the two sets of mixing channels of the second heat exchange mechanism. A flow-blocking groove is provided in the middle of the two sets of mixing channels of the first heat exchange mechanism. A plurality of flow-blocking plates are installed in the flow-blocking groove.

[0007] Preferably, a plurality of first flow dividers and second flow dividers are installed in the flow divider groove of the first heat exchanger and the second heat exchanger.

[0008] Preferably, a total cold flow inlet and a total cold flow outlet are symmetrically arranged on one side of the top plate at a lateral position, a total hot flow inlet and a total hot flow outlet are symmetrically arranged on one side of the top plate at a longitudinal position, and a connecting groove is provided on one side of the top plate to connect the total cold flow inlet, the total cold flow outlet, the total hot flow inlet, and the total hot flow outlet respectively.

[0009] Preferably, the partition has a plurality of symmetrically arranged cold flow inlets and cold flow outlets in the horizontal direction, and a plurality of symmetrically arranged hot flow inlets and hot flow outlets in the vertical direction. The cold flow inlets are connected to the main cold flow inlet, the cold flow outlets are connected to the main cold flow outlet, the hot flow inlets are connected to the main hot flow inlet, and the hot flow outlets are connected to the main hot flow outlet.

[0010] Preferably, through holes are provided at the four corners of the top plate, the partition plate, the flow channel layer and the bottom plate.

[0011] Preferably, the flow channel layer is made of two different materials, and the two sets of different materials are staggered when the flow channel layers are stacked.

[0012] The advantages of this utility model are as follows: By setting a first heat exchange mechanism and a second heat exchange mechanism on both sides of the flow channel layer, and when the flow channel layers are stacked, the first heat exchange mechanism and the second heat exchange mechanism on the side wall of the two sets of flow channel layers are spliced ​​together to form a complete medium flow channel, thereby increasing the heat dissipation area and improving the heat exchange efficiency.

[0013] This invention uses a first flow divider and a second flow divider to divide the medium. The gap between the second flow dividers is narrower than the gap between the first flow dividers, which can increase the flow velocity of the medium. At the same time, the arc-shaped flow-blocking plate can generate eddies when the medium flows, slowing down the flow velocity of the medium on the middle side, and ensuring that the medium fully fills the first heat exchange mechanism and the second heat exchange mechanism, thereby making the heat exchange uniform. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] Figure 2 This is a schematic diagram of the structure of the bottom side of the top plate of this utility model.

[0016] Figure 3 This is a schematic diagram of the structure of the bottom side of the partition of this utility model.

[0017] Figure 4 This is a schematic diagram of the upper side of the flow channel layer of this utility model.

[0018] Figure 5 This is a schematic diagram of the structure of the lower side of the flow channel layer of this utility model.

[0019] Figure 6 This is a schematic diagram of the structure of the diffusion groove, the first flow divider, and the second flow divider of this utility model.

[0020] Figure 7 This is a schematic diagram of the structure of the base plate of this utility model.

[0021] Figure 8 for Figure 5 A magnified structural diagram of A in the diagram.

[0022] The components are: 1. Top plate; 2. Baffle plate; 3. Flow channel layer; 4. Bottom plate; 5. Flow divider; 6. Diffuser groove; 7. First heat exchange mechanism; 8. Second heat exchange mechanism; 9. Flow divider groove; 10. Mixing groove; 11. Flow groove; 12. Flow blocking groove; 13. Flow blocking plate; 14. First flow divider plate; 15. Second flow divider plate; 16. Main cold flow inlet; 17. Main cold flow outlet; 18. Main hot flow inlet; 19. Main hot flow outlet; 20. Connecting groove; 21. Cold flow branch inlet; 22. Cold flow branch outlet; 23. Hot flow branch inlet; 24. Hot flow branch outlet; 25. Through hole. Detailed Implementation

[0023] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0024] like Figures 1 to 8As shown, a heat exchanger structure of dissimilar materials includes a top plate 1, a partition plate 2 attached to the bottom side of the top plate 1, a plurality of sequentially stacked flow channel layers 3 attached to the bottom side of the partition plate 2, a bottom plate 4 attached to one side of the flow channel layer 3, a plurality of flow outlets 5 symmetrically arranged on the flow channel layer 3, the flow outlets 5 on the same side being connected by a diffusion groove 6, a first heat exchange mechanism 7 and a second heat exchange mechanism 8 perpendicular to each other are respectively arranged on both sides of the flow channel layer 3, the second heat exchange mechanism 8 being symmetrically arranged on both sides of the first heat exchange mechanism 7, the first heat exchange mechanism 7 and the second heat exchange mechanism 8 including flow channel 9 connected to the corresponding flow outlet 5, one end of the flow channel 9 being connected to a mixing channel 10, a plurality of flow channels 11 being connected between the two sets of mixing channels 10 of the second heat exchange mechanism 8, and a flow-blocking groove 12 located in the middle of the two sets of mixing channels 10 of the first heat exchange mechanism 7, a plurality of flow-blocking plates 13 being installed in the flow-blocking groove 12. The first heat exchange mechanism 7 and the second heat exchange mechanism 8 located on the same side are arranged in parallel, and the second heat exchange mechanism 8 is symmetrically arranged on both sides of the first heat exchange mechanism 7. The first heat exchange mechanism 7 and the second heat exchange mechanism 8 located on opposite sides are perpendicularly distributed to each other, so that the cold flow medium and the hot flow medium can flow vertically at intervals to perform heat exchange operation. The flow baffle 13 is semi-circular. When the medium flows, it generates eddies to slow down the flow velocity of the medium, so that the medium can fully exchange heat. One side of the bottom plate 4 is smooth, and the other side is provided with the same structure as the first heat exchange mechanism 7 and the second heat exchange mechanism 8 on the flow channel layer 3. The surface of the bottom plate 4 with the first heat exchange mechanism 7 and the second heat exchange mechanism 8 is in contact with the surface of the bottommost flow channel layer 3 with the first heat exchange mechanism 7 and the second heat exchange mechanism 8, so that the first heat exchange mechanism 7 and the second heat exchange mechanism 8 form a complete medium flow channel. The bottom plate 4 is provided with a liquid distribution groove of the same size as the diversion port 5 and the diffusion groove 6 on both sides of the first heat exchange mechanism 7 and the second heat exchange mechanism 8, and the liquid distribution groove does not penetrate the bottom plate 4.

[0025] Furthermore, the dual-sided heat exchange mechanism and the flow channel layer 3 design enhance the heat dissipation area and turbulence effect. The first heat exchange mechanism 7 and the second heat exchange mechanism 8 are respectively set perpendicular to each other on both sides of the flow channel layer 3. The two mechanisms form a multi-level fluid distribution network through the synergistic effect of the flow divider 9, the mixing channel 10 and the flow barrier 12. When the hot and cold media enter the mixing channel 10 through the flow divider 9, the change in cross-sectional area creates a velocity gradient, which increases fluid disturbance and promotes turbulence generation, thereby enhancing boundary layer destruction and improving the heat transfer coefficient. The semi-circular flow barrier 13 installed in the flow barrier 12 causes local vortices in the medium of the middle flow channel, extends the flow path and slows down the flow velocity, and balances the heat exchange time difference between the middle and the two side heat exchange mechanisms. This avoids the problem of uneven heat exchange caused by the short middle flow channel path in the traditional design. The test results show that the overall heat dissipation area of ​​this utility model increases by about 30%, the turbulence intensity increases by 20%, the heat exchange uniformity is significantly improved, and the local temperature difference is reduced from ±15% in the traditional design to within ±5%.

[0026] Furthermore, the flow channel layer 3 adopts an alternating design of two different materials, with complementary properties. At the same time, the two materials of the flow channel layer 3 are arranged alternately, and the first heat exchange mechanism 7 and the second heat exchange mechanism 8 on both sides are perpendicularly distributed to each other. The hot and cold media conduct heat bidirectionally through the interface of different materials between adjacent layers, forming a multi-dimensional heat conduction path and improving the overall heat diffusion efficiency. Experiments have shown that compared with the heat exchanger of the single material flow channel layer 3, the overall heat transfer efficiency of this utility model is improved by 25%, and the structural stability is enhanced, making it suitable for complex working conditions with large temperature fluctuations.

[0027] Furthermore, the differentiated gap design between the first flow divider 14 and the second flow divider 15 (the gap of the second flow divider 15 is narrower) accelerates the local flow velocity through the Venturi effect, balances the flow distribution of different channels, and avoids flow deviation. The flow channel 11 connects the two mixing channels 10 to form a medium cross flow channel, and the hot and cold fluids achieve countercurrent heat exchange in the vertical direction, maximizing the logarithmic mean temperature difference (LMTD) and improving the heat recovery rate. Experiments have shown that the flow distribution uniformity of this utility model is improved by 40%, and the countercurrent design improves the thermal efficiency by 15%~20%.

[0028] In this embodiment, the top plate 1, the partition plate 2, the several flow channel layers 3, the bottom plate 4, and the three positioning pins are arranged in the following order according to structural design requirements: the top is a top plate 1 with the side of the top plate 1 having the connecting groove 20 facing downwards; then the partition plate 2, with the side having the first heat exchange mechanism 7 and the second heat exchange mechanism 8 facing downwards, is connected to the bottom side of the top plate 1; below the partition plate 2 are several overlapping flow channel layers 3, and the first heat exchange mechanism 7 and the second heat exchange mechanism 8 on the adjacent sides of two adjacent flow channel layers 3 are aligned and tightly joined together to form a single structure. The complete medium flow channel has a bottom plate 4 on the bottom side. The first heat exchange mechanism 7 and the second heat exchange mechanism 8 set on the partition plate 2 and the bottom plate 4 are spliced ​​with the first heat exchange mechanism 7 and the second heat exchange mechanism 8 of the flow channel layer 3 to form a complete medium flow channel. The through holes 25 of the above workpiece are in the same position and are interconnected. Four positioning pins are put into the through holes 25 in sequence for assembly to form a multi-layer heat exchanger assembly of aluminum alloy and steel superimposed on each other. Then, the multi-layer heat exchanger assembly is assembled with welding fixtures into a vacuum diffusion welding equipment for welding operation, so that multiple parts of the multi-layer heat exchanger workpiece are welded into one piece.

[0029] In this embodiment, a plurality of first diverter plates 14 and second diverter plates 15 are installed in the diversion grooves 9 of the first heat exchange mechanism 7 and the second heat exchange mechanism 8. The gap between the second diverter plates 15 is larger than that between the first diverter plates 14, so the flow velocity of the medium when flowing through the second diverter plates 15 is greater than that of the first diverter plates 14. Moreover, there are more first diverter plates 14 than second diverter plates 15. When the medium flows through the first diverter plates 14, it is diverted and slowed down. At the same time, in conjunction with the flow-blocking plate 13, the flow velocity of the medium in the first heat exchange mechanism 7 is further reduced, so that the medium can fully fill the first heat exchange mechanism 7 and the second heat exchange mechanism 8, thereby further improving the heat dissipation efficiency.

[0030] In this embodiment, a total cold flow inlet 16 and a total cold flow outlet 17 are symmetrically arranged on one side of the top plate 1 at a lateral position, and a total hot flow inlet 18 and a total hot flow outlet 19 are symmetrically arranged on one side of the top plate 1 at a longitudinal position. A connecting groove 20 is provided on one side of the top plate 1, which connects the total cold flow inlet 16, the total cold flow outlet 17, the total hot flow inlet 18, and the total hot flow outlet 19 respectively. The connecting groove 20 allows the injection of cold and hot flow media into the branch port 5.

[0031] In this embodiment, the partition 2 has several symmetrically arranged cold flow inlets 21 and cold flow outlets 22 in the horizontal direction, and several symmetrically arranged hot flow inlets 23 and hot flow outlets 24 in the vertical direction. The cold flow inlets 21 are connected to the main cold flow inlet 16, the cold flow outlets 22 are connected to the main cold flow outlet 17, the hot flow inlets 23 are connected to the main hot flow inlet 18, and the hot flow outlets 24 are connected to the main hot flow outlet 19. One side of the partition 2 is smooth, and the other side has the same structure as the first heat exchange mechanism 7 and the second heat exchange mechanism 8 on the flow channel layer 3. The smooth surface of the partition 2 is in close contact with the surface of the top plate 1 with the connecting groove 20. The surface of the partition 2 with the first heat exchange mechanism 7 and the second heat exchange mechanism 8 is in close contact with the surface of the uppermost flow channel layer 3 with the first heat exchange mechanism 7 and the second heat exchange mechanism 8, so that the first heat exchange mechanism 7 and the second heat exchange mechanism 8 form a complete medium flow channel.

[0032] In this embodiment, through holes 25 are provided at the four corners of the top plate 1, the partition plate 2, the flow channel layer 3 and the bottom plate 4.

[0033] In this embodiment, the flow channel layer 3 is made of two different materials, and the two sets of different materials are staggered when the flow channel layer 3 is stacked. The materials of the flow channel layer 3 can be stainless steel and aluminum alloy, and the stainless steel and aluminum alloy materials are staggered when the flow channel layer 3 is stacked. Stainless steel has high hardness and strong corrosion resistance, while aluminum alloy has high thermal conductivity (about 237 W / m·K) and low density, which can quickly transfer heat. Stainless steel has higher hardness than aluminum alloy, and aluminum alloy has better heat dissipation than stainless steel. This improves heat exchange efficiency while ensuring the overall rigidity of the heat exchanger. In addition, the material of the flow channel layer 3 can be selected with corrosion resistance to improve the corrosion resistance of the heat exchanger. Experiments have shown that the combination of stainless steel and aluminum alloy improves the heat dissipation efficiency by about 30% compared with the traditional single-material heat exchanger, while extending the structural life by more than 20%.

[0034] Furthermore, when combining dissimilar materials, the compatibility of their thermal expansion coefficients needs to be considered. The thermal expansion coefficient of aluminum alloy is approximately 23 × 10⁻⁻⁻⁶. 6 At / ℃, the coefficient of thermal expansion of stainless steel is approximately 17×10⁻ 6 / ℃, the difference in thermal expansion coefficients between the two materials is controllable. When the temperature changes, the difference in expansion between the two is small, which can reduce the risk of deformation or interface cracking caused by thermal stress. In addition, the superimposed design further alleviates local stress concentration and extends equipment life through the dispersed load bearing of multiple flow channel layers 3.

[0035] Furthermore, in corrosive media (such as seawater or acidic fluids), the combination of dissimilar materials can play a synergistic protective role. The passivation film formed on the surface of stainless steel can resist chemical corrosion and protect the internal structure of the flow channel layer 3. Aluminum alloy can enhance corrosion resistance through surface anodizing treatment, while its lightweight characteristics reduce the overall weight. The combination of the two enables the heat exchanger to adapt to complex working conditions, such as scenarios in offshore platforms or chemical equipment that need to cope with both corrosion and high heat dissipation requirements.

[0036] Furthermore, the alternating superposition of dissimilar materials forms a gradient thermal conductivity distribution, which can optimize the heat flow path. For example, the aluminum alloy layer with high thermal conductivity serves as the main heat transfer channel, quickly transferring heat from the hot medium to the cold medium; while the stainless steel layer serves as an auxiliary support, mitigating the risk of local overheating through its lower thermal conductivity (approximately 15 W / m·K) and avoiding material fatigue caused by thermal shock.

[0037] Furthermore, the material of the flow channel layer 3 can be selected according to the usage environment, so that the heat exchanger can adapt to various complex working environments. For example: titanium alloy + copper: titanium alloy has excellent corrosion resistance and is suitable for highly corrosive environments in seawater desalination or nuclear industry. The high thermal conductivity of copper (about 400 W / m·K) can further improve the heat exchange efficiency; nickel-based alloy + graphite composite material: nickel-based alloy has excellent high temperature resistance and is suitable for high temperature waste heat recovery. Graphite composite material has ultra-high thermal conductivity and self-lubricating properties, reducing flow channel friction resistance.

[0038] The working principle of this utility model is as follows: cold medium and hot medium flow into the main cold inlet 16 and the main hot inlet 18 respectively. The cold medium and hot medium flow into the cold flow branch inlet 21 and the hot flow branch inlet 23 respectively through the connecting groove 20. Then, the cold medium and hot medium flow into the corresponding first heat exchange mechanism 7 and second heat exchange mechanism 8 in sequence through the branch port 5. Then, the cold medium and hot medium are divided by the first branch plate 14 and the second branch plate 15 and heat exchange operation is performed through the flow groove 11. The flow directions of the cold medium and hot medium in the first heat exchange mechanism 7 and the second heat exchange mechanism 8 are perpendicular to each other. Then, the cold medium and hot medium converge from the cold flow branch outlet 22 and the hot flow branch outlet 24 respectively, and flow out from the main cold flow outlet 17 and the main hot flow outlet 19 respectively through the connecting groove 20.

[0039] This invention provides a first heat exchange mechanism 7 and a second heat exchange mechanism 8 on both sides of the flow channel layer 3. When the flow channel layers 3 are stacked, the first heat exchange mechanism 7 and the second heat exchange mechanism 8 on the side walls of the two sets of flow channel layers 3 are spliced ​​together to form a complete medium flow channel, thereby increasing the heat dissipation area and improving the heat exchange efficiency.

[0040] This invention uses a first flow divider 14 and a second flow divider 15 to divide the medium. The gap between the second flow dividers 15 is narrower than the gap between the first flow dividers 14, which can increase the flow rate of the medium. At the same time, the arc-shaped flow baffle 13 can generate eddies when the medium flows, slowing down the flow rate of the medium on the middle side, and allowing the medium to fully fill the first heat exchange mechanism 7 and the second heat exchange mechanism 8, thereby making the heat exchange uniform.

[0041] As is known from common technical knowledge, this utility model can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this utility model or its equivalents are included in this utility model.

Claims

1. A heat exchanger structure made of dissimilar materials, characterized in that: The system includes a top plate (1), a partition plate (2) attached to the bottom side of the top plate (1), and several sequentially stacked flow channel layers (3) attached to the bottom side of the partition plate (2). A bottom plate (4) is attached to one side of the flow channel layer (3). Several flow branch ports (5) are symmetrically arranged on the flow channel layer (3). The flow branch ports (5) on the same side are connected by a diffusion groove (6). A first heat exchange mechanism (7) and a second heat exchange mechanism (8) perpendicular to each other are respectively provided on both sides of the flow channel layer (3). The second heat exchange mechanism (8) Symmetrically arranged on both sides of the first heat exchange mechanism (7), the first heat exchange mechanism (7) and the second heat exchange mechanism (8) include a flow divider (9) connected to the corresponding flow divider (5), one end of the flow divider (9) is connected to a mixing channel (10), and a plurality of flow channels (11) are connected between the two sets of mixing channels (10) of the second heat exchange mechanism (8). The first heat exchange mechanism (7) is provided with a flow blocking channel (12) located in the middle of the two sets of mixing channels (10), and a plurality of flow blocking plates (13) are installed in the flow blocking channel (12).

2. The structure of a heat exchanger made of dissimilar materials according to claim 1, characterized in that: A plurality of first diversion plates (14) and second diversion plates (15) are installed in the diversion groove (9) of the first heat exchange mechanism (7) and the second heat exchange mechanism (8).

3. The structure of a heat exchanger made of dissimilar materials according to claim 1, characterized in that: The top plate (1) has a symmetrically arranged total cold flow inlet (16) and total cold flow outlet (17) on one side at a horizontal position, and a symmetrically arranged total hot flow inlet (18) and total hot flow outlet (19) on one side at a vertical position. The top plate (1) also has a connecting groove (20) on one side that connects the total cold flow inlet (16), the total cold flow outlet (17), the total hot flow inlet (18), and the total hot flow outlet (19).

4. The structure of a heat exchanger made of dissimilar materials according to claim 3, characterized in that: The partition (2) has several symmetrically arranged cold flow inlets (21) and cold flow outlets (22) in the horizontal position, and several symmetrically arranged hot flow inlets (23) and hot flow outlets (24) in the vertical position. The cold flow inlets (21) are connected to the main cold flow inlet (16), the cold flow outlets (22) are connected to the main cold flow outlet (17), the hot flow inlets (23) are connected to the main hot flow inlet (18), and the hot flow outlets (24) are connected to the main hot flow outlet (19).

5. The structure of a heat exchanger made of dissimilar materials according to claim 1, characterized in that: Through holes (25) are provided at the four corners of the top plate (1), the partition plate (2), the flow channel layer (3) and the bottom plate (4).

6. The structure of a heat exchanger made of dissimilar materials according to claim 1, characterized in that: The flow channel layer (3) is made of two different materials, and when the flow channel layer (3) is stacked, the two sets of different materials are distributed alternately.

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