Macro-architectured micro-scale vortex packing structure, method and application

Abstract

The application belongs to the field of chemical mass and heat transfer enhancement technology, and discloses a macro-quantity structured micro-scale vortex packing structure, method and application. The packing structure is a packing with a multi-scale microstructure on the surface. The microstructure causes boundary layer separation and vortex shedding when fluid flows through, generates stable micro-scale vortexes at the microstructure, and forms a macro-distributed vortex group in the packing. The vortex can cut the boundary layer, stretch and fold the fluid micro-element, and promote the periodic update of the interface, thereby improving the gas-liquid mass and heat transfer efficiency. The application significantly reduces the pressure drop. Under the same operating conditions, the pressure drop of the packing structure of the application is reduced by more than 50% compared with the conventional packing, and the pressure drop increment caused by the vortex structure is less than 15%, realizing the synergistic optimization of mass transfer enhancement and low pressure drop.

Description

Technical Field

[0001] This invention belongs to the field of chemical mass and heat transfer enhancement technology, and in particular to a structure, method and application of macro-scale microscale vortex packing. Background Technology

[0002] Structured packings are widely used in gas-liquid mass transfer processes such as distillation and absorption due to their high throughput, low pressure drop, and high separation efficiency. Typical structured packings consist of multiple layers of corrugated metal plates stacked together. The plate surfaces are usually textured, perforated, or indented to improve liquid distribution and wetting properties. The separation efficiency of the packing depends primarily on the uniformity of liquid film coverage on the plate surface, the liquid film thickness, and the gas-liquid interface renewal rate. However, the mass transfer process in traditional corrugated packings is still limited by molecular diffusion in the near-wall region. Especially under low liquid loads, the liquid film is prone to rupture, forming streams or dry zones, leading to a significant decrease in the effective mass transfer area and making it difficult to further improve separation efficiency.

[0003] To address the aforementioned issues, existing technologies employ two approaches to induce localized turbulence and vortices. One approach involves creating quadrilateral cones or pyramidal micro-protrusions on the plate surface, which can generate a lateral flow component within the liquid film, enhancing mixing. Circular or rectangular perforations on the plate can create a suspended liquid curtain, generating vortex structures such as Dean's vortices and kidney-shaped vortex pairs at the perforation edges, thereby strengthening interfacial mass transfer. The second approach utilizes porous foam materials (such as silicon carbide foam and ceramic foam) as the filler matrix. Their three-dimensional interconnected network structure allows liquid to permeate and flow along the internal framework, forming localized vortices within the channels, effectively increasing the gas-liquid contact area. Furthermore, simplified geometric models (such as tetradecahedral structures and Voronoi random structures) are used for experimental characterization and numerical simulation of the hydrodynamic behavior of foam fillers. The three-dimensional network structure or regular channels of these matrices themselves can induce a certain degree of vortex generation in the fluid. While the aforementioned methods can generate local vortices and enhance mass transfer to some extent, existing technologies mostly focus on single structural types (including using porous foam materials as a matrix, or creating multiple arrays of perforations in various shapes such as triangles, rhombuses, circles, and rectangles on the plate surface). Furthermore, they lack systematic research on the matching relationship between operating flow rate and packing geometry parameters. How to actively construct a large number of stable microscale vortices within the packing layer through reasonable packing structure design (including using porous foam materials as a matrix, or creating perforations on the plate surface), combined with precisely matched operating flow conditions, and utilize the unique hydrodynamic effects of vortices (such as cutting boundary layers, stretching and folding fluid micro-elements, and promoting periodic interface renewal) to significantly improve mass and heat transfer efficiency, while effectively controlling pressure drop and increasing operational flexibility, is a pressing technical challenge in the field of chemical process intensification. This invention addresses this technical need by proposing a method for massively constructing microscale vortex packing structures. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a structure, method and application for constructing microscale vortex packing in large quantities.

[0005] The technical solution adopted by this invention to solve its technical problem is: A macro-scale microscale vortex packing structure is disclosed. The packing structure is a packing with multi-scale microstructures on its surface. The microstructures cause boundary layer separation and vortex shedding when fluid flows through them. Stable microscale vortices are generated at the microstructures and macro-distributed vortex groups are formed in the packing. These vortices can cut the boundary layer, stretch and fold the fluid micro-elements and promote the periodic renewal of the interface, thereby improving the gas-liquid mass and heat transfer efficiency.

[0006] Furthermore, the multi-scale microstructure, by adjusting its geometric parameters, causes boundary layer separation and vortex shedding of the flowing fluid, while satisfying the Reynolds number (Re... D = u bD / v) In the range of 33-330, the Reynolds number Re p Within the range of 20-375 and the vortex formation number (V) op =λ ci Under the condition that / τ>1), stable microscale vortices are generated.

[0007] Furthermore, the macro-construction of microscale vortex packing structure includes a matrix, which is a porous foam material; Alternatively, the macro-constructed microscale vortex packing structure includes a matrix and multi-scale microstructures, wherein the multi-scale microstructures are disposed on the matrix; the matrix includes a corrugated metal plate or a vertical plate, and the multi-scale microstructures include multiple through holes arranged in an array on the matrix and disposed on the matrix.

[0008] Furthermore, the porous foam material is selected from the following two types of materials: (1) The three-dimensional network structure of real porous foam material is a multi-scale microstructure; (2) The simplified foam model based on a regular hexahedron or a regular tetrahedron has its own three-dimensional network structure as a multi-scale microstructure; the simplified geometric model of porous foam material is based on a regular hexahedron or a regular tetrahedron structure, and the specific surface area and pressure drop characteristics of real foam are matched by adjusting the rib diameter, porosity and ligament shape. Alternatively, the through hole may be triangular, rhomboid, circular, or rectangular; Alternatively, when the through-hole uses a rectangular or circular window array, the frontal side length L is 6-48 mm, the flow-side side length W is 6-48 mm, and the window opening ratio is 5%-30%. Alternatively, the apex angle of a triangular or diamond-shaped perforation can be between 15° and 90°. Alternatively, the through-hole can be provided on the substrate by the following method: Perforations of the desired shape are processed on corrugated metal plates or vertical plates using laser cutting or mechanical stamping processes.

[0009] Furthermore, the real porous foam material includes α-Al2O3 ceramic foam, SiC foam, metal foam, or carbon foam; Alternatively, the simplified foam model based on a regular hexahedron can be prepared as follows: Using a regular hexahedron as the basic unit cell structure, a three-dimensional regular skeleton structure is formed by spatial array replication; the regular hexahedron unit cell consists of 12 edges (ribs) and 8 vertices (nodes), with an edge length L. cell Determined based on the target aperture, i.e., L cell = Aperture diameter × 0.8-1.2; adjusted by rib diameter d strut The specific surface area is controlled by a diameter of 0.5-3.0 mm and a porosity ε of 60%-95%. Alternatively, the simplified foam model based on a regular tetrahedron can be prepared as follows: Using a regular tetrahedron, or Kelvin structure, as the basic unit cell, which consists of 6 square faces and 8 regular hexagonal faces, connected by 36 equal-length support pillars (ribs), the tetrahedron unit cells are periodically arrayed in three-dimensional space in a body-centered cubic stacking manner to form a complete foam skeleton model. The rib diameter d is adjusted... strut The specific surface area is controlled by a diameter of 0.5-3.0 mm and a porosity ε of 60%-95%. Alternatively, when the through hole is a triangular perforation, the laser cutting parameters are: laser power 100-300 W, cutting speed 0.5-2 m / s, auxiliary gas is high-purity nitrogen, pressure 0.5-1.5 MPa, to ensure that the perforation edge is flat and burr-free; after perforation, the plate surface is acid-washed by using 10% dilute sulfuric acid, soaking at room temperature for 10-15 min to remove the oxide layer, then rinsed with deionized water, ultrasonically cleaned with acetone for 10 min, and finally dried in an oven at 80℃ for 2 h.

[0010] Furthermore, the parameters of the matrix are: porosity 60%-95%, rib diameter 0.5mm-3.0mm, pore diameter 0.5mm-4mm, PPI 5-45, and compression ratio 2-4; Alternatively, the multi-scale microstructure can induce boundary layer separation and vortex shedding in the flowing fluid by controlling the operating flow rate, while satisfying the Reynolds number (Re). D = u bD / v) In the range of 33-330, the Reynolds number Re pWithin the range of 20-375 and the vortex formation number (V) op =λ ci Under the condition that / τ>1), stable microscale vortices are generated.

[0011] A method for constructing a microscale vortex packing structure using the macro-construction microscale vortex packing structure described above, wherein the method employs the macro-construction microscale vortex packing structure and, by adjusting the operating flow rate and gas-liquid phase operating conditions, causes boundary layer separation and vortex shedding of the fluid flowing through the microstructure, generating stable microscale vortices whose vortex positions do not change over time, and forming a macroscopically distributed vortex group within the packing layer.

[0012] Furthermore, adjusting the operating flow rate causes the Reynolds number Re to be adjusted. D The Reynolds number Re remains within the range of 33-330. p Maintaining within the range of 20-375, and the vortex formation number V op >1; The gas-liquid phase operating conditions include controlling the apparent flow rates of the gas and liquid phases, controlling the apparent flow rate of the liquid phase to be 0.0001-0.001 m / s and the apparent flow rate of the gas phase to be 0.1-1.0 m / s, so that the two-phase flow pattern is in the trickle region.

[0013] The application of the methods described above in gas-liquid mass and heat transfer.

[0014] The advantages and positive effects of this invention are as follows: 1. This invention utilizes multi-scale microstructures on the surface of the packing structure. When fluid flows through, boundary layer separation and vortex shedding occur, generating stable microscale vortices within the foam channels and at the gas-liquid interface in the open-window area. These vortex clusters then form a macroscopic distribution within the packing layer. These microscale vortices can cut the boundary layer, stretch and fold fluid micro-elements, and promote periodic interface renewal, thereby significantly improving gas-liquid mass and heat transfer efficiency. In various packing structures (porous foam, simplified foam model, open-pore plate), the gas-liquid mass transfer coefficient can be increased by more than 20%, the CO2 absorption efficiency can reach more than 90%, and the volumetric mass transfer coefficient can be increased by more than 50%.

[0015] 2. The packing structure of this invention mainly consists of a matrix and microstructures disposed on the surface of the matrix. The matrix is ​​a porous foam material or a corrugated metal plate. The microstructures include a three-dimensional network structure of real foam, a simplified foam model based on a regular hexahedron or regular tetrahedron, and arrays of triangular perforations, rhomboid perforations, or rectangular / circular windows. By controlling the geometric parameters, arrangement, and surface wettability of the microstructures, boundary layer separation and vortex shedding occur when the fluid flows through them, forming stable microscale vortices (such as Dean's vortices and kidney-shaped vortex pairs in "twin liquid films") within the foam channels and open window areas, and forming a macroscopically distributed vortex group within the packing layer. Since the microscale vortices induced by the microstructures can cut the boundary layer, stretch and fold fluid micro-elements, and promote periodic renewal of the interface, the gas-liquid mass and heat transfer efficiency can be significantly improved. At the same time, by optimizing the geometric parameters of the microstructures, pressure drop can be effectively controlled, operational flexibility can be increased, and the processing capacity of the equipment can be improved.

[0016] 3. This invention, by systematically matching the packing structure (matrix type and geometric parameters) with the operating flow conditions, proposes for the first time a method to control the Reynolds number (Re... D In 33-330, Re p (in the range of 20-375) and eddy formation number (V) op >1) A quantitative method for actively constructing microscale vortices has universality and operability.

[0017] 4. The packing structure of this invention is flexible and diverse. It can use porous foam material (real three-dimensional network structure or simplified model of regular hexahedron / regular tetrahedron) as the matrix, or open multiple arrays of perforations of various shapes such as triangles, rhombuses, circles, and rectangles on the surface of a metal plate. The shape of the opening is not limited, as long as the flow conditions are met, vortices can be generated, which reduces the processing difficulty and improves industrial applicability.

[0018] 5. This invention significantly reduces pressure drop. Under the same operating conditions, the pressure drop of the packing structure of this invention is reduced by more than 50% compared with conventional packing, and the pressure drop increment caused by vortex construction is less than 15%, achieving synergistic optimization of enhanced mass transfer and low pressure drop.

[0019] 6. This invention significantly improves heat transfer efficiency. The cooling characteristic coefficient can be increased by more than 40% compared to conventional packing, the cooling tower efficiency can be increased by more than 10 percentage points, and the heat exchange performance is significantly enhanced.

[0020] 7. The structure of this invention is a packing structure for gas-liquid contact equipment in the fields of oil refining, petrochemical, and chemical industries, and is suitable for gas-liquid mass and heat transfer processes such as distillation, absorption, desorption, and heat exchange. Attached Figure Description

[0021] Figure 1 This is a front view schematic diagram of the cross-sectional structure of the α-Al2O3 ceramic foam matrix used as the filler structure in this invention; Figure 2 This is a front view schematic diagram of a simplified foam model of the filler structure matrix hexahedron structure in this invention; Figure 3 This is a front view schematic diagram of a simplified foam model of the filler structure matrix tetradecahedron structure in this invention; Figure 4 This is a front view schematic diagram of the triangular perforated array of microstructures on the surface of the filler structure matrix in this invention; Figure 5 This is a front view schematic diagram of the rectangular window array of microstructures on the surface of the filler structure matrix in this invention; Among them, 1-matrix, 2-filler surface structure (opening or multi-scale microstructure), 3-triangular perforation, 4-rectangular window, 5-regular hexahedral unit, 6-regular tetrahedral unit. Detailed Implementation

[0022] The present invention will be further described below with reference to the embodiments. The following embodiments are descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0023] The various experimental operations involved in the specific embodiments are all conventional techniques in the field. For parts not specifically annotated in this document, those skilled in the art can refer to various commonly used reference books, scientific and technological documents or related instructions and manuals prior to the filing date of this invention to carry out the operations.

[0024] This invention aims to solve the technical problems of limited mass and heat transfer efficiency, low operational flexibility, and high pressure drop caused by uneven liquid film distribution, slow interface renewal, and lack of stable microscale vortices in existing packing structures. To this end, this invention provides a mass-produced microscale vortex packing structure, such as... Figures 1 to 5 As shown, the packing structure is a packing with multi-scale microstructures on its surface. The microstructures cause boundary layer separation and vortex shedding when the fluid flows through them, generating stable microscale vortices at the microstructures and forming a macroscopically distributed vortex group within the packing. These vortices can cut the boundary layer, stretch and fold the fluid micro-elements, and promote the periodic renewal of the interface, thereby improving the gas-liquid mass and heat transfer efficiency.

[0025] Furthermore, the multi-scale microstructure, by adjusting its geometric parameters, causes boundary layer separation and vortex shedding of the flowing fluid, while satisfying the Reynolds number (Re... D = u bD / v) In the range of 33-330, the Reynolds number Re p Within the range of 20-375 and the vortex formation number (V) op =λ ci Under the condition that / τ>1), stable microscale vortices are generated.

[0026] Furthermore, such as Figures 1 to 3 As shown, the macro-construction microscale vortex packing structure includes a matrix 1, which is a porous foam material.

[0027] Preferably, the porous foam material can be selected from the following two types of materials (when the matrix is ​​a porous foam material or a simplified foam model, its own three-dimensional network structure or regular channels are the filler surface structure, i.e., multi-scale microstructure): (1) Real porous foam materials (such as ceramic foam (preferably α-Al2O3 ceramic foam, which is the most stable crystal phase of alumina ceramic, i.e., corundum crystal structure), SiC foam, metal foam or carbon foam), their own three-dimensional network structure is a multi-scale microstructure (also known as the filler surface structure). (2) The simplified foam model based on a regular hexahedron or a regular tetrahedron has its own three-dimensional network structure as a multi-scale microstructure (also known as the filler surface structure); the simplified geometric model of porous foam material is based on a regular hexahedron or a regular tetrahedron structure, and the specific surface area and pressure drop characteristics of real foam are matched by adjusting the rib diameter, porosity and ligament shape.

[0028] Preferably, the simplified foam model based on a regular hexahedron is prepared by the following method: Using a regular hexahedron as the basic unit cell structure, a three-dimensional regular skeleton structure is formed by spatial array replication. The regular hexahedron unit cell consists of 12 edges (ribs) and 8 vertices (nodes), with an edge length L. cell Determined based on the target aperture (L) cell = Aperture diameter × 0.8-1.2). By adjusting the rib diameter d strut The specific surface area is controlled by the thickness (0.5-3.0 mm) and porosity ε (60%-95%). In specific preparation, 3D printing technology can be used for direct molding: using photosensitive resin or metal powder as raw materials, the model is printed layer by layer according to a CAD-designed hexahedral array model, with a layer thickness of 0.05-0.1 mm and an exposure time of 8-15 s / layer. Alternatively, a sacrificial template method can be used: using a 3D-printed hexahedral plastic skeleton as a template, ceramic slurry is impregnated, and then the template is removed after sintering to obtain a ceramic hexahedral foam model. This yields a simplified foam model based on a hexahedron.

[0029] The simplified foam model based on a regular tetrahedron is prepared as follows: Using a regular tetrahedron (Kelvin structure) as the basic unit cell, each unit cell consists of 6 square faces and 8 regular hexagonal faces, connected by 36 supports (ribs) of equal length. These tetrahedron unit cells are arranged in a body-centered cubic stacking pattern in a periodic array in three-dimensional space to form a complete foam skeleton model. The rib diameter d is adjusted...strut The specific surface area is controlled by the porosity ε (60%-95%) and the diameter (0.5-3.0 mm). In specific preparation, 3D printing technology can be used for direct molding: a periodic array model of tetradecahedral unit cells (array size: 5×5×5 to 20×20×20 unit cells) is constructed using CAD software, and photosensitive resin or metal powder is used as raw material. Stereolithography (SLA) or selective laser melting (SLM) technology is used to print the model layer by layer, with a layer thickness of 0.05-0.1 mm. Alternatively, a template method can be used: a 3D-printed tetradecahedral plastic skeleton is used as a template, impregnated with ceramic slurry, sintered, and then the template is removed to obtain a ceramic tetradecahedral foam model. This yields a simplified foam model based on a tetradecahedron.

[0030] Furthermore, such as Figures 4 to 5 As shown, the macro-scale microscale vortex packing structure includes a matrix 1 and a multi-scale microstructure 2, wherein the multi-scale microstructure is disposed on the matrix; the matrix includes a corrugated metal plate or a vertical plate, and the multi-scale microstructure includes multiple through holes arranged in an array on the matrix.

[0031] Preferably, the through-holes include various shapes such as triangles, rhombuses, circles, and rectangles. The shape of the through-holes (perforations) is not limited; they can adopt various shapes such as triangles, rhombuses, circular windows, and rectangular windows, arranged in an array. When using rectangular or circular window arrays, the upstream side length L is 6-48 mm, the downstream side length W is 6-48 mm, and the window opening ratio is 5%-30%. This is used to form a "twin liquid film" on the plate where the wall film and the confined free film inside the window coexist, inducing Dean vortices and kidney-shaped vortex pairs to enhance mass transfer. The apex angle of the triangular or rhomboid perforations is 15° to 90°, used to induce fluid separation at the corner points, forming a free shear layer, and generating Karman vortex street-type vortex shedding downstream.

[0032] The size and arrangement of the perforations can be adjusted as needed, but the key is to control the operating flow rate so that the fluid meets the following conditions when flowing through it: Reynolds number (Re D = u b D / v) in the range of 33-330, Reynolds number Re p Within the range of 20-375 and the vortex formation number (V) op =λ ci / τ>1).

[0033] This invention uses porous foam material (real foam structure or simplified hexahedral / tetrahedral model) as the matrix, or creates multiple arrays of perforations in various shapes such as triangles, rhombuses, circles, and rectangles on the surface of a corrugated metal plate / vertical plate, and precisely controls the operating flow rate (Reynolds number) to ensure that the fluid flows through it under specific hydrodynamic conditions, thereby actively constructing a large number of stable microscale vortex groups within the packing layer. The aforementioned perforations are only created on the plate; the foam material matrix itself does not require additional perforations. This invention systematically matches the packing structure (matrix type and geometric parameters) with the operating flow rate conditions to ensure that the fluid flows through it under the Reynolds number (Re... D = u bD / v) In the range of 33-330, the Reynolds number Re p Within the range of 20-375 and the vortex formation number (V) op =λ ci Under the condition of / τ>1), microscale vortices are actively constructed. Compared with the prior art, this invention proposes for the first time a method for quantitatively controlling vortex generation by adjusting the operating flow rate, which has universality and operability.

[0034] Preferably, the through-hole is formed on the substrate by the following method: Perforations of the desired shape are machined into corrugated metal plates or vertical plates using laser cutting or mechanical stamping processes. Taking a triangular perforation as an example, the laser cutting parameters are: laser power 100-300 W, cutting speed 0.5-2 m / s, high-purity nitrogen as the assist gas, and pressure 0.5-1.5 MPa, to ensure smooth, burr-free perforation edges. After perforation, the plate surface is acid-washed (10% dilute sulfuric acid, soaked at room temperature for 10-15 min) to remove the oxide layer, then rinsed with deionized water, ultrasonically cleaned with acetone for 10 min, and finally dried in an 80℃ oven for 2 h.

[0035] Furthermore, the parameters of the matrix are: porosity 60%-95%, rib diameter 0.5mm-3.0mm, pore size 0.5mm-4mm, PPI 5-45, and compression ratio 2-4. The surface is provided with filler featuring multi-scale microstructures. Furthermore, the multi-scale microstructure induces boundary layer separation and vortex shedding in the flowing fluid by regulating the operating flow rate, while satisfying the Reynolds number (Re). D = u bD / v) In the range of 33-330, the Reynolds number Re p Within the range of 20-375 and the vortex formation number (V) op =λ ci Under the condition that / τ>1), stable microscale vortices are generated.

[0036] A method for constructing a microscale vortex packing structure using the macro-construction of microscale vortex packing structure as described above, wherein the method employs the aforementioned macro-construction of microscale vortex packing structure and adjusts the operating flow rate (to achieve the Reynolds number Re) D The Reynolds number Re remains within the range of 33-330. p Maintaining within the range of 20-375, and the vortex formation number V op >1) and gas-liquid phase operating conditions (the gas-liquid phase operating conditions include controlling the apparent flow rates of the gas and liquid phases, controlling the apparent flow rate of the liquid phase to 0.0001-0.001 m / s and the apparent flow rate of the gas phase to 0.1-1.0 m / s, so that the two-phase flow pattern is in the trickle region), so that the fluid flowing through the microstructure undergoes boundary layer separation and vortex shedding, generating stable microscale vortices whose vortex positions do not change with time.

[0037] The specific preparation and testing methods are as follows: Example 1: A macro-scale microscale vortex packing structure is disclosed. The packing structure is a packing with multi-scale microstructures on its surface. The microstructures cause boundary layer separation and vortex shedding when fluid flows through them. Stable microscale vortices are generated at the microstructures and macro-distributed vortex groups are formed in the packing. These vortices can cut the boundary layer, stretch and fold the fluid micro-elements and promote the periodic renewal of the interface, thereby improving the gas-liquid mass and heat transfer efficiency.

[0038] The macro-scale micro-scale vortex packing structure includes a matrix 1. This packing structure is composed of a matrix 1, which is α-Al₂O₃ ceramic foam (e.g., ...). Figure 1 As shown), the porosity is 84%, the rib diameter is 0.6-1.0 mm, and the PPI is 20. The three-dimensional network structure of the matrix 1 itself is the surface structure of the filler, and no additional pores are required. A 30 wt% DGA aqueous solution was used as the absorbent, and 13% CO2 and 87% N2 were used as simulated flue gas. CO2 absorption experiments were carried out under gas-liquid countercurrent operation, with a gas flow rate of 0.1-1.0 m / s and a liquid flow rate of 0.0001-0.001 m / s, so that Re D ≈100, Re p ≈80, V op >1. Experiments showed that the CO2 removal efficiency reached over 90%, and the volumetric mass transfer coefficient k L a reached 0.032 s -1 Compared to traditional Raschig ring packing, it has a 0.021 st -1 It increases pressure by 52.4%, with a pressure drop of approximately 1.5 kPa / m, which is more than 50% lower than that of random packing.

[0039] The relevant detection methods for Comparative Examples 1 and 2 are exactly the same as those for Example 1, except that: in Comparative Example 1, the α-Al2O3 ceramic foam is replaced with Raschig rings; in Comparative Example 2, the α-Al2O3 ceramic foam is replaced with a metal corrugated plate (wherein, the traditional packing also uses a 30 wt% DGA aqueous solution as the absorbent, 13% CO2 and 87% N2 as simulated flue gas, and the CO2 absorption experiment is carried out under gas-liquid countercurrent operation).

[0040] In Comparative Example 3, the operating flow conditions in Example 1 were changed to fluid dynamic conditions that do not satisfy the present invention. The gas flow rate and liquid flow rate were adjusted to achieve a Reynolds number Re. D Reduced to 10-20 (below 33), Reynolds number Re p Reduced to 5-15 (below 20), and under this condition, the vortex formation number V op Less than 1. Other conditions (such as absorbent concentration, temperature, filler structure, etc.) are exactly the same as in Example 1.

[0041] Table 1 Comparison of detection results between Example 1 and the comparative example

[0042] Compared with Comparative Example 1 (ordinary matrix): The CO2 removal efficiency of Comparative Example 3 (68%) is similar to that of Comparative Example 1 (65%), indicating that the structural advantages of ceramic foam cannot be realized when the flow conditions of this invention are not met, and its performance is not fundamentally different from that of ordinary matrix. This comparison further highlights the decisive role of operating flow conditions in activating the vortex enhancement mechanism.

[0043] Compared with Comparative Example 2 (without microstructure): All indicators of Comparative Example 3 are significantly better than those of Comparative Example 2 (without microstructure), indicating that the ceramic foam matrix itself has certain structural advantages. However, compared with Example 1, which meets the conditions of this invention, the difference is still huge (the mass transfer coefficient differs by about 28%), indicating that the foam structure alone is not enough, and it must be combined with precisely controlled operating flow rate to achieve its maximum efficiency.

[0044] Comparison with Example 1: The only difference between Comparative Example 3 and Example 1 is that the operating flow rate does not meet the hydrodynamic conditions of the present invention (Re D = u bD / v) In the range of 33-330, the Reynolds number Re p Within the range of 20-375 and the vortex formation number (V) op =λ ci / τ>1), causing its CO2 removal efficiency to drop significantly from over 90% to approximately 68%, and the volumetric mass transfer coefficient k L a from 0.032 s -1Reduced to 0.023 s -1 Although the pressure drop decreased slightly (from 1.5 kPa / m to 1.2 kPa / m), the sacrifice in mass transfer performance far outweighed the gains in pressure drop. This fully demonstrates that merely having a foam structure without meeting the flow conditions defined in this invention cannot actively construct a stable microscale vortex group, thus failing to achieve efficient mass transfer.

[0045] The above comparative results fully demonstrate that the core technical feature of this invention lies in precisely controlling the operating flow rate to meet specific hydrodynamic conditions (Re D = u bD / v) In the range of 33-330, the Reynolds number Re p Within the range of 20-375 and the vortex formation number (V) op =λ ci / τ>1)), actively constructing stable microscale vortex groups, thereby achieving a significant improvement in mass and heat transfer efficiency.

[0046] Meanwhile, by comparing Example 1 and Comparative Examples 1-3, it can be seen that in the method of the present invention, the α-Al2O3 ceramic foam and the gas flow rate of 0.1-1.0 m / s and the liquid flow rate of 0.0001-0.001 m / s, make Re D ≈100, Re p ≈80, V op >1. These two conditions have a synergistic effect, which can synergistically improve the CO2 removal efficiency and volumetric mass transfer coefficient k after treatment. L a.

[0047] Example 2: A macro-scale microscale vortex packing structure is disclosed. The packing structure is a packing with multi-scale microstructures on its surface. The microstructures cause boundary layer separation and vortex shedding when fluid flows through them. Stable microscale vortices are generated at the microstructures and macro-distributed vortex groups are formed in the packing. These vortices can cut the boundary layer, stretch and fold the fluid micro-elements and promote the periodic renewal of the interface, thereby improving the gas-liquid mass and heat transfer efficiency.

[0048] The macro-scale microscale vortex packing structure includes a matrix 1 and a multi-scale microstructure, wherein the multi-scale microstructure is disposed on the matrix; the matrix includes a corrugated metal plate, and the multi-scale microstructure includes multiple through holes arranged in an array on the matrix.

[0049] This packing structure consists of a substrate 1 and a packing surface structure 2 disposed on the surface of the substrate. The substrate 1 is a corrugated metal plate, and the packing surface structure 2 consists of triangular through holes arranged in an equilateral triangular (i.e., staggered at 60°) array on the plate (e.g.,...). Figure 4As shown, the specific preparation method for the triangular perforation with a 90° apex angle is as follows: A laser cutting process is used with a laser power of 200 W, a cutting speed of 1 m / s, and high-purity nitrogen as the auxiliary gas at a pressure of 1.0 MPa. Triangular perforations with a side length of 4 mm and a 30° apex angle are machined on a 0.4 mm thick stainless steel corrugated plate. The perforations are arranged in a staggered pattern with a row spacing of 5 mm and a column spacing of 5 mm. After cutting, the plate is subjected to acid washing (10% dilute sulfuric acid, soaking at room temperature for 10 min), deionized water rinsing, acetone ultrasonic cleaning for 10 min, and drying at 80℃ for 2 h. The large eddy simulation method is used to simulate the counter-current flow of water and air through the structure, and the inlet flow velocity is adjusted to make Re... D ≈150, Re p ≈120, V op >1.

[0050] Fluid dynamics simulation tools (CFD) were used to simulate the counter-current flow of water and air through the structure using the large eddy simulation method. The inlet velocity was adjusted to achieve Re D ≈150, Re p ≈120, V op 1. First, a simulation was performed on an unperforated flat plate under the same conditions to obtain the baseline value K of the liquid phase mass transfer coefficient. L =1.8×10 -4 m / s, which is on the same order of magnitude as the mass transfer coefficient of the unperforated plate in the prior art (approximately 1.6-1.9 × 10 m / s). -4 Simulations were performed on a staggered array structure of triangular perforations. The results show that when fluid flows through the acute edges of the triangular perforations, boundary layer separation occurs, forming an alternating von Karman vortex street downstream of the perforations. The Strouhal number is 0.139, the drag coefficient is 2.17, and the liquid phase mass transfer coefficient Km / s is [missing value]. L =2.4×10 -4 m / s, compared to the reference value of 1.8 × 10 for an unperforated flat plate. -4 Compared to m / s, the improvement is 33.3%.

[0051] Table 2 Comparison of CFD simulation results in Example 2

[0052] This embodiment demonstrates that, under the condition of satisfying the flow rate (Re) of the present invention... D ≈150, Re p ≈120, V op >1) Under the condition that the triangular perforated staggered array structure induces the Karman vortex street, it can significantly enhance liquid film mixing and interface renewal, thereby increasing the liquid phase mass transfer coefficient by 33.3% compared with the unperforated plate, which is better than the existing perforated plate structure (10-20%).

[0053] Example 3: A macro-scale microscale vortex packing structure is disclosed. The packing structure is a packing with multi-scale microstructures on its surface. The microstructures cause boundary layer separation and vortex shedding when fluid flows through them. Stable microscale vortices are generated at the microstructures and macro-distributed vortex groups are formed in the packing. These vortices can cut the boundary layer, stretch and fold the fluid micro-elements and promote the periodic renewal of the interface, thereby improving the gas-liquid mass and heat transfer efficiency.

[0054] The macro-scale microscale vortex packing structure includes a matrix 1 and a multi-scale microstructure 2, wherein the multi-scale microstructure is disposed on the matrix; the matrix includes a corrugated metal plate or a vertical plate, and the multi-scale microstructure includes multiple through holes arranged in an array on the matrix.

[0055] This filler structure consists of a substrate 1 and a filler surface structure 2 disposed on the surface of the substrate. The substrate 1 is an aluminum plate, and the microstructure 2 is a rectangular window array 5 (e.g., Figure 5 As shown), the oncoming side length L = 12 mm, the flowing side length W = 12 mm, and the window opening rate is approximately 12%. The rectangular windows are arranged in a staggered manner. The specific preparation method of the rectangular windows is as follows: using laser cutting technology, 12 mm × 12 mm rectangular windows are processed on a 0.4 mm thick aluminum plate. The rectangular windows are arranged in a staggered manner with a row spacing of 15 mm and a column spacing of 15 mm, and the window opening rate is approximately 12%. After cutting, the plate is surface treated: burrs are removed by polishing with 800-grit sandpaper, ultrasonic cleaning with acetone for 10 min, rinsing with deionized water, and drying at 80℃ for 2 h. Using water as the absorbent and CO2 as the gas phase, a physical absorption experiment is carried out under gas-liquid countercurrent operation. The liquid flow rate is 0.0003-0.001 m / s, and the gas flow rate is 0.1-0.5 m / s, so that Re D ≈120, Re p ≈90, V op >1. Experimental results show that when liquid flows through the open window region, a "twin liquid film" is formed, consisting of a wall film and a confined free film inside the window. Strong Dean vortices and kidney vortex pairs are generated in the free film inside the window, with vortex intensity reaching as high as 7000 s⁻¹. -1 It is highly correlated with CO2 concentration distribution (correlation coefficient 0.93). Quantitative calculations show that the average liquid-phase mass transfer coefficient K in the open window region... L It is 26.9% higher than the upstream wall region (from 5.2×10). -5 m / s increased to 6.6×10 -5 m / ), average K in the entire flow direction L It is 19.2% better than windowless wall masks (from 5.1×10). -5 m / s increased to 6.1×10 -5(m / s). Simultaneously, this structure enables CO2 absorption efficiency to reach over 85%, with a pressure drop increase of less than 15% compared to the windowless plate. This embodiment demonstrates that the perforated vertical plate significantly enhances gas-liquid mass transfer by inducing a "twin liquid film" and strong vortices.

[0056] Table 3. Comparison of mass transfer performance of rectangular window array in Example 3

[0057] Example 4: A macro-scale microscale vortex packing structure is disclosed. The packing structure is a packing with multi-scale microstructures on its surface. The microstructures cause boundary layer separation and vortex shedding when fluid flows through them. Stable microscale vortices are generated at the microstructures and macro-distributed vortex groups are formed in the packing. These vortices can cut the boundary layer, stretch and fold the fluid micro-elements and promote the periodic renewal of the interface, thereby improving the gas-liquid mass and heat transfer efficiency.

[0058] The macro-scale microscale vortex packing structure includes a matrix 1 and a multi-scale microstructure 2, wherein the multi-scale microstructure is disposed on the matrix; the matrix includes a corrugated metal plate or a vertical plate, and the multi-scale microstructure includes multiple through holes arranged in an array on the matrix.

[0059] This filler structure consists of a matrix 1 and a filler surface structure 2 disposed on the surface of the matrix. The matrix 1 is a simplified hexahedral foam model (e.g., Figure 2 As shown), the porosity is 85%, the rib diameter is 0.8 mm, and the average pore diameter is approximately 1.5 mm. The specific preparation method for the simplified hexahedral foam model is as follows: using a regular hexahedron as the basic unit cell structure, a three-dimensional regular skeleton structure is formed by spatial array replication. The regular hexahedral unit cell consists of 12 edges (rib diameters) and 8 vertices (nodes), with an edge length L. cell Determined based on the target aperture (L) cell = Aperture diameter × 0.8-1.2). By adjusting the rib diameter d strut The specific surface area is controlled by the diameter (0.5-3.0 mm) and porosity ε (60%-95%). In specific preparation, 3D printing technology is used for direct molding: using photosensitive resin as raw material, the model is printed layer by layer according to a CAD-designed hexahedral array model (array size: 15×15×15 unit cells), with a layer thickness of 0.05 mm and an exposure time of 10 s / layer. After printing, uncured resin is removed by cleaning with ethanol, followed by UV curing for 30 min. The regular channels of the matrix 1 itself constitute the surface structure of the filler. Using water as the cooling medium and air as the cooling gas, heat and mass transfer experiments are conducted in a counter-current wet cooling tower, adjusting the gas-liquid flow rate to achieve the desired Re... D ≈90, Re p ≈70, V op>1. Experiments showed that when the inlet water temperature was 38℃ and the water-to-air ratio was 0.57, after the system stabilized (approximately 20-30 minutes), the inlet and outlet water temperatures and the inlet and outlet dry-bulb and wet-bulb temperatures of the air were recorded. Then, using the Merkel enthalpy difference method and the Chebyshev integral method, the cooling characteristic coefficient KaV / L was calculated to be 2.00, which is 42.9% higher than the 1.40 of traditional PVC corrugated plate packing. The cooling tower efficiency... It reaches 60%, which is 10% higher than that of traditional packing (wherein, traditional packing is also measured in a counter-flow wet cooling tower, with water as the cooling medium and air as the cooling gas, in heat and mass transfer experiments).

[0060] Table 4 Comparison of detection performance in Example 4

[0061] Example 5 A macro-scale microscale vortex packing structure is disclosed. The packing structure is a packing with multi-scale microstructures on its surface. The microstructures cause boundary layer separation and vortex shedding when fluid flows through them. Stable microscale vortices are generated at the microstructures and macro-distributed vortex groups are formed in the packing. These vortices can cut the boundary layer, stretch and fold the fluid micro-elements and promote the periodic renewal of the interface, thereby improving the gas-liquid mass and heat transfer efficiency.

[0062] The macro-scale microscale vortex packing structure includes a matrix 1. This packing structure consists of the matrix 1 and a packing surface structure 2 disposed on the surface of the matrix (when the matrix is ​​a porous foam material or a simplified foam model, its own three-dimensional network structure or regular channels are the packing surface structure). The matrix 1 is a regular tetrahedral network (e.g., ...). Figure 3 As shown), the porosity is 90%, and the average pore size is approximately 2 mm. Microstructure 2 is a regular tetradecahedral unit. The specific preparation method of the simplified tetradecahedral foam model is as follows: using a regular tetradecahedron (Kelvin structure) as the basic unit cell, which consists of 6 square faces and 8 regular hexagonal faces, connected by 36 pillars of equal length (rib diameter approximately 0.5 mm). The regular tetradecahedral unit cells are arranged in a body-centered cubic stacking pattern in a periodic array in three-dimensional space (array size: 10×10×30 unit cells), and formed using photopolymerization 3D printing technology: using photosensitive resin as raw material, the regular tetradecahedral array model is designed by CAD, the printing layer thickness is 0.05 mm, the exposure time is 10 s / layer, and the printing is carried out layer by layer. After printing, the uncured resin is removed by cleaning with ethanol, and then cured under ultraviolet light for 30 min. The regular channels of the matrix 1 itself constitute the surface structure of the filler. A heat and mass transfer experiment was conducted in a counter-current wet cooling tower using water as the cooling medium and air as the cooling gas. The gas-liquid flow rate was adjusted to adjust the Re D ≈80, Re p ≈60, V op>1. Experimentally, when the inlet water temperature is 38℃ and the water-to-air ratio is 0.57, after the system stabilizes (approximately 20-30 minutes), the inlet and outlet water temperatures and the dry and wet bulb temperatures of the inlet and outlet air are recorded. Then, the cooling characteristic coefficient K is calculated using the Merkel enthalpy difference method and the Chebyshev integral method. a V / L = 2.14, a 52.8% improvement compared to the 1.40 of traditional PVC corrugated sheet packing; cooling tower efficiency It reaches 65%, which is 15% higher than that of traditional packing (wherein, traditional packing is also measured in a counter-flow wet cooling tower, with water as the cooling medium and air as the cooling gas, in heat and mass transfer experiments).

[0063] Table 5 Comparison of detection performance in Example 5

[0064] Although embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations, and modifications are possible without departing from the spirit and scope of the invention and the appended claims. Therefore, the scope of the invention is not limited to the contents disclosed in the embodiments.

Claims

1. A macro-scale micro-scale vortex packing structure, characterized in that: The packing structure is a packing with multi-scale microstructures on its surface. The microstructures cause boundary layer separation and vortex shedding when the fluid flows through them. Stable microscale vortices are generated at the microstructures and macroscopically distributed vortex groups are formed in the packing. These vortices can cut the boundary layer, stretch and fold the fluid micro-elements and promote the periodic renewal of the interface, thereby improving the gas-liquid mass and heat transfer efficiency.

2. The method for constructing a large-scale micro-scale vortex packing structure according to claim 1, characterized in that: The multi-scale microstructure, by controlling its geometric parameters, causes boundary layer separation and vortex shedding of the flowing fluid, while satisfying the Reynolds number (Re). D = u bD / v) In the range of 33-330, the Reynolds number Re p Within the range of 20-375 and the vortex formation number (V) op =λ ci Under the condition that / τ>1), stable microscale vortices are generated.

3. The method for constructing a large-scale micro-scale vortex packing structure according to claim 1, characterized in that: The macro-scale microscale vortex packing structure includes a matrix, which is a porous foam material; Alternatively, the macro-constructed microscale vortex packing structure includes a matrix and multi-scale microstructures, wherein the multi-scale microstructures are disposed on the matrix; the matrix includes a corrugated metal plate or a vertical plate, and the multi-scale microstructures include multiple through holes arranged in an array on the matrix and disposed on the matrix.

4. The method for constructing a large-scale micro-scale vortex packing structure according to claim 3, characterized in that: The porous foam material is selected from the following two types of materials: (1) The three-dimensional network structure of real porous foam material is a multi-scale microstructure; (2) The simplified foam model based on a regular hexahedron or a regular tetrahedron has its own three-dimensional network structure as a multi-scale microstructure; the simplified geometric model of porous foam material is based on a regular hexahedron or a regular tetrahedron structure, and the specific surface area and pressure drop characteristics of real foam are matched by adjusting the rib diameter, porosity and ligament shape. Alternatively, the through hole may be triangular, rhomboid, circular, or rectangular; Alternatively, when the through-hole uses a rectangular or circular window array, the frontal side length L is 6-48 mm, the flow-side side length W is 6-48 mm, and the window opening ratio is 5%-30%. Alternatively, the apex angle of a triangular or diamond-shaped perforation can be between 15° and 90°. Alternatively, the through-hole can be provided on the substrate by the following method: Perforations of the desired shape are processed on corrugated metal plates or vertical plates using laser cutting or mechanical stamping processes.

5. The method for constructing a large-scale micro-scale vortex packing structure according to claim 4, characterized in that: The real porous foam material includes α-Al2O3 ceramic foam, SiC foam, metal foam, or carbon foam; Alternatively, the simplified foam model based on a regular hexahedron can be prepared as follows: Using a regular hexahedron as the basic unit cell structure, a three-dimensional regular skeleton structure is formed by spatial array replication; the regular hexahedron unit cell consists of 12 edges (ribs) and 8 vertices (nodes), with an edge length L. cell Determined based on the target aperture, i.e., L cell = Aperture diameter × 0.8-1.2; adjust the rib diameter d strut The specific surface area is controlled by a diameter of 0.5-3.0 mm and a porosity ε of 60%-95%. Alternatively, the simplified foam model based on a regular tetrahedron can be prepared as follows: Using a regular tetrahedron, or Kelvin structure, as the basic unit cell, which consists of 6 square faces and 8 regular hexagonal faces, connected by 36 equal-length support pillars (ribs), the tetrahedron unit cells are periodically arrayed in three-dimensional space in a body-centered cubic stacking manner to form a complete foam skeleton model. The rib diameter d is adjusted... strut The specific surface area is controlled by a diameter of 0.5-3.0 mm and a porosity ε of 60%-95%. Alternatively, when the through hole is a triangular perforation, the laser cutting parameters are: laser power 100-300 W, cutting speed 0.5-2 m / s, auxiliary gas is high-purity nitrogen, pressure 0.5-1.5 MPa, to ensure that the perforation edge is flat and burr-free; after perforation, the plate surface is acid-washed by using 10% dilute sulfuric acid, soaking at room temperature for 10-15 min to remove the oxide layer, then rinsed with deionized water, ultrasonically cleaned with acetone for 10 min, and finally dried in an oven at 80℃ for 2 h.

6. The method for constructing a large-scale micro-scale vortex packing structure according to any one of claims 3 to 5, characterized in that: The parameters of the matrix are: porosity 60%-95%, rib diameter 0.5mm-3.0mm, pore diameter 0.5mm-4mm, PPI 5-45, and compression ratio 2-4; Alternatively, the multi-scale microstructure can induce boundary layer separation and vortex shedding in the flowing fluid by controlling the operating flow rate, while satisfying the Reynolds number (Re). D = u bD / v) In the range of 33-330, the Reynolds number Re p Within the range of 20-375 and the vortex formation number (V) op =λ ci Under the condition that / τ>1), stable microscale vortices are generated.

7. A method for constructing microscale vortex packing structures using the macro-construction of microscale vortex packing structures as described in any one of claims 1 to 6, characterized in that: The method employs the macro-construction of microscale vortex packing structure. By adjusting the operating flow rate and gas-liquid phase operating conditions, the fluid flowing through the microstructure undergoes boundary layer separation and vortex shedding, generating stable microscale vortices whose vortex positions do not change over time, and forming a macroscopically distributed vortex group within the packing layer.

8. The method according to claim 7, characterized in that: Regulating the operating flow to increase the Reynolds number Re D The Reynolds number Re remains within the range of 33-330. p Maintaining within the range of 20-375, and the vortex formation number V op > 1; The gas-liquid phase operating conditions include controlling the apparent flow rates of the gas and liquid phases, controlling the apparent flow rate of the liquid phase to be 0.0001-0.001 m / s and the apparent flow rate of the gas phase to be 0.1-1.0 m / s, so that the two-phase flow pattern is in the trickle region.

9. The application of the method as described in claim 7 or 8 in gas-liquid mass and heat transfer.

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