Asymmetric variable cross-section angle pore structure and fluid uniformity control method thereof

Abstract

The invention discloses an asymmetric variable cross-section angle hole structure, and relates to the technical field of heat exchange equipment. The corner holes are formed in the corners of the heat exchange plates, the sections of the corner holes are gradually reduced from the inlet ends to the outlet ends, the sizes of the sections of the outlet ends and the inlet ends of the adjacent corner holes are completely the same, the heat exchange plates are spliced together, and the corner holes in the same corner form a contraction type fluid channel. The fluid channel comprises a first flow channel position and a second flow channel position, the first flow channel position is located at an inlet of the fluid channel, the second flow channel position is located at an outlet of the fluid channel, and the cross-sectional area of the corner hole at the first flow channel position is twice the cross-sectional area of the corner hole at the second flow channel position; the fluid channels between the corner holes are designed in a gradually-shrinking mode, the vortex phenomenon at the tail ends of the fluid channels is avoided, fluid between the heat exchange plates is evenly distributed, and the heat transfer efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat exchange equipment, and in particular relates to an asymmetric variable-section angular hole structure and a method for controlling fluid uniformity thereof. Background Art

[0002] A plate heat exchanger is a new type of high-efficiency heat exchanger composed of a series of stacked, corrugated metal sheets. Thin rectangular channels are formed between the plates, through which heat is exchanged. Plate heat exchangers are ideal for liquid-to-liquid and liquid-to-vapor heat exchange. They feature high heat transfer efficiency, minimal heat loss, a compact and lightweight structure, a small footprint, easy installation and cleaning, a wide range of applications, and a long service life.

[0003] The heat exchange body of a plate heat exchanger is generally composed of a number of stacked heat exchange plates, and fluid channels for fluid flow are formed between adjacent heat exchange plates; corner holes are respectively provided on the four corners of the heat exchange plate. At present, most plate heat exchangers adopt a circular corner hole design, and the fluid enters the flow channel through the corner holes at the end of the heat exchange plate. Before the fluid enters the heat exchange area on the heat exchange plate, it needs to pass through the guide area. The guide area is provided with multiple guide channels. The guide channels distribute the fluid in the width direction of the heat exchange plate to prevent biased flow and the occurrence of local dead zone phenomena. At present, for special working conditions, such as large flow rates of hot and cold media or easy scaling of the media, due to the design of conventional circular corner holes, there is a fluid that flows through the circular corner holes to the surface of the heat exchange plate, which cannot be evenly and completely distributed in the heat exchange area, resulting in uneven heat exchange, reduced heat exchange efficiency, dead zones in local areas, and easy retention of fluid.

[0004] In addition, the channels between the plates of the plate heat exchanger are very narrow, generally only 2-5 mm. When the heat exchange medium contains large particles or fibrous substances, the channels between the plates are easily blocked. Summary of the Invention

[0005] The purpose of the present invention is to provide an asymmetric variable-section angular hole structure and a method for controlling fluid uniformity thereof. Through the design of the angular hole structure, the problems of reduced heat transfer efficiency or easy blockage of inter-plate channels caused by uneven fluid distribution in the prior art are effectively solved.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An asymmetric variable-section corner hole structure, wherein the corner hole is located at the corner of the heat exchange plate, and the cross-section of the corner hole gradually decreases from the inlet end to the outlet end. The cross-sectional dimensions of the outlet end and the inlet end of adjacent corner holes are exactly the same. Several heat exchange plates are spliced together, and the corner holes on the same corner form a contracting fluid channel; the fluid channel includes a first flow channel position and a second flow channel position, wherein the first flow channel position is located at the inlet of the fluid channel, and the second flow channel position is located at the outlet of the fluid channel, and the cross-sectional area of the corner hole at the first flow channel position is twice the cross-sectional area of the corner hole at the second flow channel position.

[0008] Optionally, a plurality of flow guides are diffusely arranged along the circumference of the corner hole; the height of the flow guides is 0.05-0.1 times the diameter of the corner hole.

[0009] Optionally, the guide member is a guide rib, the surface of the guide rib is protruding from the plate surface of the heat exchange plate, and a guide channel is formed between two adjacent guide ribs.

[0010] Optionally, the guide channel includes a starting end and an extending end, the starting end is located at the edge of the corner hole, and the caliber of the extending end is larger than the caliber of the starting end.

[0011] Optionally, the guide member is a guide groove punched on the side plate surface around the corner hole; the cross-section of the guide groove is U-shaped.

[0012] Optionally, the guide groove extends from the edge of the corner hole to the peripheral side of the corner hole, and the guide groove is designed to be gradually expanded.

[0013] Optionally, a spiral guide groove is provided on the inner wall of the corner hole; the spiral angle of the spiral guide groove is 15°-45°, and the depth is 1-3 mm.

[0014] Optionally, a plurality of protrusions are provided on the inner wall of the corner hole; the protrusions are distributed in a regular or irregular array, and the height of the protrusions is 0.5-2 mm.

[0015] A method for controlling fluid uniformity, including an asymmetric variable cross-section angular hole structure, includes:

[0016] 1) The fluid flows from the first flow channel position to the second flow channel position through the corner hole;

[0017] 2) During the flow of the fluid, the cross-section of the fluid channel gradually decreases to avoid the generation of vortex phenomena at the end of the fluid channel, and the fluid is evenly distributed between the heat exchange plates.

[0018] Beneficial effects: The asymmetric variable cross-section angular hole structure and the method for controlling fluid uniformity thereof of the present invention have the following advantages:

[0019] (1) The fluid channels between the corner holes are designed to be tapered to avoid the generation of vortexes at the end of the fluid channels. The fluid is evenly distributed between the heat exchange plates, thereby improving heat transfer efficiency.

[0020] (2) The setting of flow guides around the corner holes optimizes fluid distribution and avoids biased flow and dead zones;

[0021] (3) The inner wall of the corner hole is provided with a spiral guide groove, which makes the fluid form a spiral flow in the corner hole, generating centrifugal force; impurity particles are thrown to the outside of the corner hole wall under the action of centrifugal force, avoiding deposition in the low-speed area; the spiral flow continuously flushes the wall surface, reducing the adhesion of impurities; the spiral structure destroys the laminar boundary layer, increases the turbulence intensity, and makes it difficult for impurities to stay on the wall surface; at the same time, the spiral guide groove converts the axial flow of the fluid into a spiral advance, reducing the direct impact of the fluid and the wall surface, thereby reducing friction resistance and reducing pressure drop;

[0022] (4) The inner wall of the corner hole is provided with protrusions, which periodically disturb the fluid, destroy the laminar bottom layer, and prevent impurities from stably adhering; tiny vortices are generated behind the protrusions, which enhance the local shear force and wash away the wall sediments; at the same time, the protrusions can change the flow velocity gradient near the wall, delay the flow separation point, and reduce the pressure drop loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the overall structure of the corner hole in Example 1;

[0024] Figure 2 This is a schematic diagram of the application of the corner hole in Example 1;

[0025] Figure 3 is a cross-sectional view of a fluid channel;

[0026] Figure 4 Schematic diagram of the overall structure of the corner hole in Example 2;

[0027] Figure 5 This is a schematic diagram of the application of the corner hole in Example 2;

[0028] Figure 6 Schematic diagram of the overall structure of the corner hole in Example 3;

[0029] Figure 7 This is a schematic diagram of the application of the corner hole in Example 3;

[0030] Figure 8 Schematic diagram of the overall structure of the corner hole in Example 4;

[0031] Figure 9 Schematic diagram of the application of the corner hole in Example 4.

[0032] In the figure: 1. Corner hole; 2. Heat exchange plate; 3. Fluid channel; 31. First flow channel position; 32. Second flow channel position; 4. Guide rib; 5. Guide channel; 51. Starting end; 52. Extension end; 6. Heat exchange area; 7. Guide groove; 8. Spiral guide groove; 9. Protrusion. DETAILED DESCRIPTION

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the present invention will be briefly introduced below in conjunction with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0034] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0035] In the description of the present invention, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0036] Example 1

[0037] like Figure 1-Figure 3 As shown, the asymmetric variable cross-section corner hole structure provided in this embodiment, the corner hole 1 is located at the corner of the heat exchange plate 2, the cross-section of the corner hole 1 gradually decreases from the inlet end to the outlet end, and the cross-sectional dimensions of the outlet end and the inlet end of adjacent corner holes 1 are exactly the same, see Figure 3 Several heat exchange plates 2 are spliced together, and the corner holes 1 on the same corner form a contracting fluid channel 3; the fluid channel 3 includes a first flow channel position 31 and a second flow channel position 32, the first flow channel position 31 is located at the inlet of the fluid channel 3, and the second flow channel position 32 is located at the outlet of the fluid channel 3, and the cross-sectional area of the corner hole 1 at the first flow channel position 31 is twice the cross-sectional area of the corner hole 1 at the second flow channel position 32.

[0038] In specific applications, the heat exchange plate 2 is usually pressed from corrosion-resistant metal sheets such as stainless steel and titanium alloy, and includes corrugated plates, sealing gaskets and corner holes; wherein the surface of the corrugated plates is designed with corrugated patterns such as herringbone and diagonal lines to enhance fluid turbulence, improve heat transfer efficiency, and increase the rigidity of the plates; in this embodiment, it is a herringbone pattern; rubber or polymer gaskets are installed around the plates to form a sealed flow channel to prevent medium leakage and guide the alternating flow of the fluid, which is not shown in the drawings of this embodiment; corner holes are set at the four corners of the plates, and after assembly, fluid channels are formed for the inflow and outflow of hot and cold fluids; in this embodiment, taking unilateral flow as an example, the fluid flows in from a corner hole on one side and then flows out from another corner hole on the same side, wherein only the fluid flows into the channel, that is, the fluid channel 3 in this embodiment adopts a contraction design, and the outflow channel adopts a traditional cylindrical channel design; several plates are stacked and fixed between the fixed pressure plate and the movable pressure plate by tightening bolts to form parallel flow channels.

[0039] In order to improve the uniformity of fluid distribution in the inter-plate channels and reduce dead zones, see Figure 1 A plurality of flow guides are diffusely arranged along the circumference of the corner hole 1; the height of the flow guides is 0.05-0.1 times the diameter of the corner hole 1.

[0040] Specifically, in this embodiment, see Figure 2 The guide member is a guide rib 4, the surface of the guide rib 4 protrudes from the plate surface of the heat exchange plate 2, and a guide channel 5 is formed between two adjacent guide ribs 4; wherein, the guide rib 4 can be arranged in a straight line or in an irregular curve; their function is to guide the fluid to be evenly distributed.

[0041] Preferably, the guide channel 5 includes a starting end 51 and an extension end 52, the starting end 51 is located at the edge of the corner hole 1, and the diameter of the extension end 52 is larger than the diameter of the starting end 51; the guide channel 5 is designed to be gradually expanded, which can make the fluid more evenly distributed to the inter-plate channel, avoid local eddy currents or dead zones, and improve heat exchange efficiency; in addition, the pressure of the fluid drops due to friction and turbulence during the flow process, and the gradually expanding structure can slow down the flow rate, convert part of the kinetic energy into static pressure, reduce the pressure drop at the extension end 52, and reduce the energy consumption of the system.

[0042] In one embodiment, see Figure 2A spiral guide groove 8 is provided on the inner wall of the corner hole 1; the spiral angle of the spiral guide groove 8 is 15°-45°, and the depth is 1-3mm; the spiral guide groove 8 causes the fluid to form a spiral flow in the corner hole 1, generating centrifugal force; impurity particles are thrown to the outside of the wall of the corner hole 1 under the action of centrifugal force to avoid deposition in the low-speed area; the spiral flow continuously scours the wall surface, reducing the adhesion of impurities; the spiral structure destroys the laminar boundary layer, increases the turbulence intensity, and makes it difficult for impurities to stay on the wall surface; at the same time, the spiral guide groove 8 converts the axial flow of the fluid into spiral advancement, reducing the direct impact of the fluid on the wall surface, thereby reducing friction resistance and reducing pressure drop.

[0043] Example 2

[0044] like Figure 3-Figure 5 As shown, the asymmetric variable cross-section corner hole structure provided in this embodiment, the corner hole 1 is located at the corner of the heat exchange plate 2, the cross-section of the corner hole 1 gradually decreases from the inlet end to the outlet end, and the cross-sectional dimensions of the outlet end and the inlet end of adjacent corner holes 1 are exactly the same, see Figure 3 Several heat exchange plates 2 are spliced together, and the corner holes 1 on the same corner form a contracting fluid channel 3; the fluid channel 3 includes a first flow channel position 31 and a second flow channel position 32, the first flow channel position 31 is located at the inlet of the fluid channel 3, and the second flow channel position 32 is located at the outlet of the fluid channel 3, and the cross-sectional area of the corner hole 1 at the first flow channel position 31 is twice the cross-sectional area of the corner hole 1 at the second flow channel position 32.

[0045] In specific applications, the heat exchange plate 2 is usually pressed from corrosion-resistant metal sheets such as stainless steel and titanium alloy, and includes corrugated plates, sealing gaskets and corner holes; wherein the surface of the corrugated plates is designed with corrugated patterns such as herringbone and diagonal lines to enhance fluid turbulence, improve heat transfer efficiency, and increase the rigidity of the plates; in this embodiment, it is a herringbone pattern; rubber or polymer gaskets are installed around the plates to form sealed flow channels to prevent medium leakage and guide the alternating flow of fluids, which are not shown in the drawings of this embodiment; corner holes are set at the four corners of the plates, and after assembly, fluid flow channels are formed for the inflow and outflow of hot and cold fluids; in this embodiment, taking unilateral flow as an example, the fluid flows in from a corner hole on one side and then flows out from another corner hole on the same side, wherein only the fluid flows into the channel, that is, the fluid channel 3 in this embodiment adopts a contraction design, and the outflow channel adopts a traditional cylindrical channel design; several plates are stacked and fixed between the fixed pressure plate and the movable pressure plate by tightening bolts to form parallel flow channels.

[0046] In order to improve the uniformity of fluid distribution in the inter-plate channels and reduce dead zones, see Figure 4 A plurality of flow guides are diffusely arranged along the circumference of the corner hole 1; the height of the flow guides is 0.05-0.1 times the diameter of the corner hole 1.

[0047] Specifically, in this embodiment, see Figure 4 The guide member is a guide groove 7 punched on the side plate surface around the corner hole 1; the cross-section of the guide groove 7 is U-shaped; wherein the height of the guide member is the depth of the guide groove 7, and the guide groove 7 can be arranged in a straight line or in an irregular curve; its function is to guide the fluid to be evenly distributed.

[0048] Preferably, the guide groove 7 extends from the edge of the corner hole 1 to the side of the corner hole 1, and the guide groove 7 is designed to be gradually expanded; the fluid can be more evenly distributed to the inter-plate channel, avoiding local eddies or dead zones, and improving heat exchange efficiency; in addition, the fluid pressure drops due to friction and turbulence during the flow process, and the gradually expanding structure can slow down the flow rate, convert part of the kinetic energy into static pressure, reduce the pressure drop at the extension end 52, and reduce the energy consumption of the system.

[0049] In one embodiment, see Figure 4 A spiral guide groove 8 is provided on the inner wall of the corner hole 1; the spiral angle of the spiral guide groove 8 is 15°-45°, and the depth is 1-3mm; the spiral guide groove 8 causes the fluid to form a spiral flow in the corner hole 1, generating centrifugal force; impurity particles are thrown to the outside of the wall of the corner hole 1 under the action of centrifugal force to avoid deposition in the low-speed area; the spiral flow continuously scours the wall surface, reducing the adhesion of impurities; the spiral structure destroys the laminar boundary layer, increases the turbulence intensity, and makes it difficult for impurities to stay on the wall surface; at the same time, the spiral guide groove 8 converts the axial flow of the fluid into spiral advancement, reducing the direct impact of the fluid on the wall surface, thereby reducing friction resistance and reducing pressure drop.

[0050] Example 3

[0051] like Figure 3 and Figure 6-Figure 7 As shown, the asymmetric variable cross-section corner hole structure provided in this embodiment, the corner hole 1 is located at the corner of the heat exchange plate 2, the cross-section of the corner hole 1 gradually decreases from the inlet end to the outlet end, and the cross-sectional dimensions of the outlet end and the inlet end of adjacent corner holes 1 are exactly the same, see Figure 3 Several heat exchange plates 2 are spliced together, and the corner holes 1 on the same corner form a contracting fluid channel 3; the fluid channel 3 includes a first flow channel position 31 and a second flow channel position 32, the first flow channel position 31 is located at the inlet of the fluid channel 3, and the second flow channel position 32 is located at the outlet of the fluid channel 3, and the cross-sectional area of the corner hole 1 at the first flow channel position 31 is twice the cross-sectional area of the corner hole 1 at the second flow channel position 32.

[0052] In specific applications, the heat exchange plate 2 is usually pressed from corrosion-resistant metal sheets such as stainless steel and titanium alloy, and includes corrugated plates, sealing gaskets and corner holes; wherein the surface of the corrugated plate is designed with corrugated patterns such as herringbone and diagonal lines to enhance fluid turbulence, improve heat transfer efficiency, and increase the rigidity of the plate; in this embodiment, it is a herringbone pattern; rubber or polymer gaskets are installed around the plate to form a sealed flow channel to prevent medium leakage and guide the alternating flow of the fluid, which is not shown in the drawings of this embodiment; the corner holes are set at the four corners of the plate, and after assembly, fluid flow channels are formed for the inflow and outflow of hot and cold fluids; in this embodiment, taking unilateral flow as an example, the fluid flows in from the corner hole on one side and then flows out from the other corner hole 1 on the same side, wherein only the fluid flows into the channel, that is, the fluid channel 3 in this embodiment adopts a contraction design, and the outflow channel adopts a traditional cylindrical channel design; several plates are stacked and fixed between the fixed pressure plate and the movable pressure plate by tightening bolts to form parallel flow channels.

[0053] In order to improve the uniformity of fluid distribution in the inter-plate channels and reduce dead zones, see Figure 6 A plurality of flow guides are diffusely arranged along the circumference of the corner hole 1; the height of the flow guides is 0.05-0.1 times the diameter of the corner hole 1.

[0054] Specifically, in this embodiment, see Figure 7 The guide member is a guide rib 4, the surface of the guide rib 4 protrudes from the plate surface of the heat exchange plate 2, and a guide channel 5 is formed between two adjacent guide ribs 4; wherein, the guide rib 4 can be arranged in a straight line or in an irregular curve; their function is to guide the fluid to be evenly distributed.

[0055] Preferably, the guide channel 5 includes a starting end 51 and an extension end 52, the starting end 51 is located at the edge of the corner hole 1, and the diameter of the extension end 52 is larger than the diameter of the starting end 51; the guide channel 5 is designed to be gradually expanded, which can make the fluid more evenly distributed to the inter-plate channel, avoid local eddy currents or dead zones, and improve heat exchange efficiency; in addition, the pressure of the body drops due to friction and turbulence during the flow process, and the gradually expanding structure can slow down the flow rate, convert part of the kinetic energy into static pressure, reduce the pressure drop at the extension end 52, and reduce the energy consumption of the system.

[0056] In one embodiment, see Figure 6 , a plurality of protrusions 9 are provided on the inner wall of the corner hole 1; the protrusions 9 are distributed in a regular or irregular array, and the height of the protrusions 9 is 0.5-2 mm; specifically, the protrusions 9 can be as shown in the attached embodiment of the present invention Figure 6As shown, it is elliptical, and can be any shape such as circular, trapezoidal, etc. The protrusion 9 periodically disturbs the fluid, destroys the laminar bottom layer, and prevents impurities from stably adhering. A small vortex is generated behind the protrusion 9, which enhances the local shear force and washes away the wall sediments. At the same time, the protrusion 9 can change the flow velocity gradient near the wall, delay the flow separation point, and reduce the pressure drop loss.

[0057] Example 4

[0058] like Figure 3 and Figure 8-Figure 9 As shown, the asymmetric variable cross-section corner hole structure provided in this embodiment, the corner hole 1 is located at the corner of the heat exchange plate 2, the cross-section of the corner hole 1 gradually decreases from the inlet end to the outlet end, and the cross-sectional dimensions of the outlet end and the inlet end of adjacent corner holes 1 are exactly the same, see Figure 3 Several heat exchange plates 2 are spliced together, and the corner holes 1 on the same corner form a contracting fluid channel 3; the fluid channel 3 includes a first flow channel position 31 and a second flow channel position 32, the first flow channel position 31 is located at the inlet of the fluid channel 3, and the second flow channel position 32 is located at the outlet of the fluid channel 3, and the cross-sectional area of the corner hole 1 at the first flow channel position 31 is twice the cross-sectional area of the corner hole 1 at the second flow channel position 32.

[0059] In specific applications, the heat exchange plate 2 is usually pressed from corrosion-resistant metal sheets such as stainless steel and titanium alloy, and includes corrugated plates, sealing gaskets and corner holes; wherein the surface of the corrugated plate is designed with corrugated patterns such as herringbone and diagonal lines to enhance fluid turbulence, improve heat transfer efficiency, and increase the rigidity of the plate; in this embodiment, it is a herringbone pattern; rubber or polymer gaskets are installed around the plate to form a sealed flow channel to prevent medium leakage and guide the alternating flow of the fluid, which is not shown in the drawings of this embodiment; the corner holes 1 are arranged at the four corners of the plate, and after assembly, fluid flow channels are formed for the inflow and outflow of hot and cold fluids; in this embodiment, taking unilateral flow as an example, the fluid flows in from a corner hole on one side and flows out from another corner hole on the same side, wherein only the fluid flows into the channel, that is, the fluid channel 3 in this embodiment adopts a contraction design, and the outflow channel adopts a traditional cylindrical channel design; several plates are stacked and fixed between the fixed pressure plate and the movable pressure plate by tightening bolts to form parallel flow channels.

[0060] In order to improve the uniformity of fluid distribution in the inter-plate channels and reduce dead zones, see Figure 8 A plurality of flow guides are diffusely arranged along the circumference of the corner hole 1; the height of the flow guides is 0.05-0.1 times the diameter of the corner hole 1.

[0061] Specifically, in this embodiment, see Figure 8The guide member is a guide groove 7 punched on the side plate surface around the corner hole 1; the cross-section of the guide groove 7 is U-shaped; wherein the height of the guide member is the depth of the guide groove 7, and the guide groove 7 can be arranged in a straight line or in an irregular curve; its function is to guide the fluid to be evenly distributed.

[0062] Preferably, the guide groove 7 extends from the edge of the corner hole 1 to the side of the corner hole 1, and the guide groove 7 is designed to be gradually expanded; the fluid can be more evenly distributed to the inter-plate channel, avoiding local eddies or dead zones, and improving heat exchange efficiency; in addition, the fluid pressure drops due to friction and turbulence during the flow process, and the gradually expanding structure can slow down the flow rate, convert part of the kinetic energy into static pressure, reduce the pressure drop at the extension end 52, and reduce the energy consumption of the system.

[0063] In one embodiment, see Figure 9 , a plurality of protrusions 9 are provided on the inner wall of the corner hole 1; the protrusions 9 are distributed in a regular or irregular array, and the height of the protrusions 9 is 0.5-2 mm; specifically, the protrusions 9 can be as shown in the attached embodiment of the present invention Figure 6 As shown, it is elliptical, and can be any shape such as circular, trapezoidal, etc. The protrusion 9 periodically disturbs the fluid, destroys the laminar bottom layer, and prevents impurities from stably adhering. A small vortex is generated behind the protrusion 9, which enhances the local shear force and washes away the wall sediments. At the same time, the protrusion 9 can change the flow velocity gradient near the wall, delay the flow separation point, and reduce the pressure drop loss.

[0064] The asymmetric variable-section corner hole structure provided by the present invention has a fluid channel 3 between the corner holes 1 with a tapered design, which avoids the generation of vortex phenomenon at the end of the fluid channel 3, and evenly distributes the fluid between each heat exchange plate 2, thereby improving the heat transfer efficiency.

[0065] Example 5

[0066] The fluid uniformity control method provided in this embodiment includes an asymmetric variable cross-section angular hole structure, and the control method includes:

[0067] 1) The fluid flows from the first flow channel position 31 to the second flow channel position 32 of the fluid channel 3 through the corner hole 1;

[0068] 2) During the fluid flow process, the cross section of the fluid channel 3 is gradually reduced to avoid the generation of vortex phenomenon at the end of the fluid channel 3, and the fluid is evenly distributed between the heat exchange plates 2.

[0069] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. Asymmetric variable cross-section corner hole structure, wherein the corner hole (1) is located at the corner of the heat exchange plate (2), characterized in that: The cross-section of the corner hole (1) gradually decreases from the inlet end to the outlet end, and the cross-sectional dimensions of the outlet ends and inlet ends of adjacent corner holes (1) are exactly the same. A plurality of heat exchange plates (2) are spliced together, and the corner holes (1) on the same corner form a contraction-type fluid channel (3); the fluid channel (3) includes a first flow channel position (31) and a second flow channel position (32), the first flow channel position (31) is located at the inlet of the fluid channel (3), and the second flow channel position (32) is located at the outlet of the fluid channel (3), and the cross-sectional area of the corner hole (1) at the first flow channel position (31) is twice the cross-sectional area of the corner hole (1) at the second flow channel position (32).

2. The asymmetric variable cross-section angular hole structure according to claim 1, characterized in that: A plurality of flow guides are diffusely arranged along the circumference of the corner hole (1); the height of the flow guides is 0.05-0.1 times the diameter of the corner hole (1).

3. The asymmetric variable cross-section angular hole structure according to claim 2, characterized in that: The flow guide member is a flow guide rib (4), the surface of the flow guide rib (4) is arranged to protrude from the plate surface of the heat exchange plate (2), and a flow guide channel (5) is formed between two adjacent flow guide ribs (4).

4. The asymmetric variable cross-section angular hole structure according to claim 3, characterized in that: The guide channel (5) comprises a starting end (51) and an extending end (52), wherein the starting end (51) is located at the edge of the corner hole (1), and the caliber of the extending end (52) is larger than the caliber of the starting end (51).

5. The asymmetric variable cross-section angular hole structure according to claim 2, characterized in that: The flow guide member is a flow guide groove (7) punched on the side plate surface around the corner hole (1); the cross section of the flow guide groove (7) is U-shaped.

6. The asymmetric variable cross-section angular hole structure according to claim 5, characterized in that: The guide groove (7) extends from the edge of the corner hole (1) toward the peripheral side of the corner hole (1), and the guide groove (7) is designed to expand gradually.

7. The asymmetric variable cross-section angular hole structure according to claim 1, characterized in that: A spiral guide groove (8) is provided on the inner wall of the corner hole (1); the spiral guide groove (8) has a spiral angle of 15°-45° and a depth of 1-3 mm.

8. The asymmetric variable cross-section angular hole structure according to claim 1, characterized in that: A plurality of protrusions (9) are provided on the inner wall of the corner hole (1); the protrusions (9) are distributed in a regular or irregular array, and the height of the protrusions (9) is 0.5-2 mm.

9. A method for controlling fluid uniformity, comprising the asymmetric variable cross-section angular hole structure according to any one of claims 1 to 9, characterized in that: The control method includes: 1) Fluid flows from a first flow channel position (31) to a second flow channel position (32) of a fluid channel (3) through the corner hole (1); 2) During the flow of the fluid, the cross section of the fluid channel (3) is gradually reduced, thereby avoiding the generation of vortex phenomena at the end of the fluid channel (3) and ensuring uniform distribution of the fluid between the heat exchange plates (2).

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