Composite mass transfer heat exchange flat plate unit, integrated inner part and isothermal desulfurization tower

Abstract

This invention discloses a composite mass transfer heat exchange plate unit, integrated internal components, and an isothermal desulfurization tower, belonging to the technical field of chemical mass transfer and heat exchange equipment. The composite mass transfer heat exchange plate unit includes a plate-shaped body with an internal cavity. An array of supporting connecting parts is arranged within the cavity. The two main surfaces of the plate-shaped body bulge outwards, forming an undulating profile with alternating recesses and protrusions. The projected area of ​​the supporting connecting parts accounts for 1.4% to 12.6% of the plate's projected area, and the wall thickness difference in the protruding areas is ≤0.5mm. The integrated internal components consist of multiple composite mass transfer heat exchange plate units arranged vertically and parallel within a frame. Adjacent composite mass transfer heat exchange plate units form external flow channels for gas-liquid circulation. The isothermal desulfurization tower includes these internal components, achieving synergistic in-situ removal of reaction heat and enhanced mass transfer. This invention integrates heat exchange channels and mass transfer interfaces simultaneously through an integrally molded thin-shell structure, making it suitable for strongly exothermic reaction systems such as the amine desulfurization process.

Description

Technical Field

[0001] This invention belongs to the technical field of chemical mass transfer and heat exchange equipment, specifically relating to a composite mass transfer and heat exchange plate unit, integrated internal components, and isothermal desulfurization tower. Background Technology

[0002] In the fields of natural gas purification and chemical tail gas treatment, the amine desulfurization method is the most widely used technology. Its core is the chemical absorption of acidic gases such as H2S and CO2 by the amine liquid in the absorption tower. This reaction is a strongly exothermic process, releasing a large amount of heat, which leads to a fundamental engineering problem: if the heat of reaction cannot be removed in time, the temperature of the absorbent will rise significantly. According to the principle of gas-liquid phase equilibrium, the temperature rise will severely reduce the solubility of acidic gases in the amine liquid, thereby directly weakening the driving force of the entire mass transfer process, and ultimately limiting the desulfurization accuracy and processing capacity of the unit.

[0003] Therefore, to maintain efficient and stable desulfurization operations, two closely related engineering requirements must be addressed simultaneously: first, the immediate removal of reaction heat to maintain thermodynamic conditions favorable for absorption (i.e., high solubility at low temperatures); and second, enhanced gas-liquid mass transfer to fully utilize the high mass transfer driving force. Ideally, the internal components of the tower should possess the dual attributes of both a high-efficiency heat exchanger and high-efficiency packing. However, under traditional technological approaches, these two functions are often performed separately by components with vastly different design philosophies, making it difficult to achieve deep synergy in a single internal component.

[0004] To address these challenges, existing technologies have primarily adopted two approaches. The first approach focuses on optimizing mass transfer. For example, CN121041978A discloses a flat-plate membrane internal for an absorber tower, which increases the contact area through a specific surface texture design. However, this internal component itself lacks active heat exchange capabilities and will rapidly reach its efficiency bottleneck in strongly exothermic systems due to uncontrolled temperature rise. The second approach focuses on heat management and is further subdivided into two technical paradigms. The more traditional approach is external heat exchange, which involves connecting independent indirect heat exchangers (such as plate-and-shell wide-narrow channel heat exchangers, typically the desulfurization slurry cooling heat exchanger disclosed in CN109443055A) in series on the absorber tower's circulation pipeline for indirect cooling of the circulating liquid. However, this approach spatially separates heat exchange from the reaction process, resulting in a complex system with severely delayed response (response time measured in minutes), and cannot eliminate the instantaneous heat accumulation (second-level release) at the reaction interface. A more advanced approach is the in-tower integration paradigm, which essentially attempts to introduce and optimize independent, universal heat exchange units within the mass transfer region, belonging to a "combined" technology path. Representative solutions under this paradigm include: CN110433635A discloses a high-efficiency desulfurization and white smoke elimination device and process, which arranges multiple horizontal tube bundles in the desulfurization tower, allowing the spray liquid to be cooled outside the tubes and come into contact with the process gas. Although this scheme achieves spatial superposition, its heat exchange unit is a general smooth circular tube, and the outer wall of the tube only serves as a passive liquid film carrier. No original structural optimization is performed on the gas-liquid mass transfer interface, thus limiting the mass transfer efficiency. To further enhance interface perturbation, CN108771947A discloses an integrated device and method for deep waste heat recovery and CO2 capture of high-humidity flue gas, which introduces concave-convex or vertical corrugated structures on the outer wall of the serpentine heat exchange tubes. This represents an attempt to optimize the surface morphology of general-purpose pipes in a combined approach. However, whether simply arranging general-purpose pipes or corrugating their surfaces, the essence of "combination" remains unchanged: the mass transfer interface (outer wall of the tube, whether smooth or corrugated) and the heat exchange channel (inner cavity of the tube) are still two independently designed functional units combined through manufacturing. This paradigm has inherent limitations determined by its structural origins in pursuing the intrinsic integration of mass transfer and heat exchange, extreme structural compactness, and synchronous thermal response.

[0005] In summary, current technologies, when addressing the synergistic challenges of mass transfer and heat exchange, either offer only single functions or, while attempting to combine them, remain limited to the arrangement and combination of existing mature components. This results in a failure to achieve deep integration of "efficient mass transfer" and "instantaneous heat exchange" at the core component structural design level. Furthermore, existing technologies do not consider the coupling between the wettability of the mass transfer interface and heat exchange efficiency—even if the heat exchange channel and mass transfer interface are close, uneven liquid film distribution (such as on a smooth tube outer wall) can still lead to localized dry burning and mass transfer failure. Therefore, the industry urgently needs to break through the existing "combinatorial" paradigm and develop an innovative internal component technology. Its core is no longer a variation or simple combination of any traditional heat exchange or mass transfer component, but rather, from the design source, through an integrated manufacturing process, simultaneously creating a new functional unit where the mass transfer interface and heat exchange channel are essentially integrated, geometrically conformal, and functionally mutually reinforcing. This is further supplemented by superhydrophilic surface control to fundamentally resolve the core contradiction that instantaneous removal of reaction heat and efficient enhancement of the mass transfer process must occur synergistically. Summary of the Invention

[0006] This invention aims to overcome the shortcomings of existing technologies and provide a composite mass transfer and heat exchange plate unit, integrated internal components, and an isothermal desulfurization tower. The core objective of this invention is to resolve the inherent contradiction in the highly exothermic gas-liquid reaction process of amine desulfurization, where it is difficult to achieve deep synergy between a "highly efficient mass transfer interface" and a "real-time heat exchange channel" on a single component. Specifically, this invention strives to provide an innovative internal component that simultaneously creates functional elements of the mass transfer interface and heat exchange channel from the structural design perspective, replacing existing "functional zoning" or "combined superposition" technical solutions. This achieves in-situ, real-time removal of reaction heat and highly efficient enhancement of the mass transfer process, ultimately improving the desulfurization accuracy, processing capacity, operational reliability, and energy efficiency of the device.

[0007] The core design concept of this invention lies in breaking the traditional physical boundaries between "heat exchange components" and "mass transfer components," and simultaneously integrating "heat exchange channels" and "mass transfer interfaces" through topological optimization of a single thin-shell body. Specifically, by controlling two key geometric parameters—the proportion of the projected area of ​​the support connection on the plate surface and the wall thickness fluctuation—the inherent contradiction between "thin-shell pressure-bearing stiffness" and "efficient heat and mass transfer area" is resolved: the array of support connections simultaneously serves as the buckling-resistant support network of the plate-shaped thin-shell structure, the topological nodes of the internal micro-cavities, and the alignment reference for the undulating contour of the outer surface—its configuration, which overlaps with the recessed portion, ensures the geometric consistency of the undulating contour of the shell surface; combined with the turbulent secondary flow induced by the bidirectional undulating contour in the external flow channel and the spreading effect of the superhydrophilic coating, rapid heat removal at the interface and high-frequency renewal of the liquid film interface are achieved. Furthermore, to address the thermal stress problem of vertical thin shells with internal cooling media during thermal cycles, a non-rigid connection structure consisting of comb-tooth limiting grooves and bottom support mesh replaces the rigid clamping method of traditional fillers or plate heat exchangers, providing a structural reliability basis for large-scale applications.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention is to provide a composite mass transfer heat exchange plate unit, comprising a plate-shaped body, the plate-shaped body being a thin shell structure with an internal cavity, having a first end and a second end opposite to each other in the X direction, a first side portion and a second side portion opposite to each other in the Y direction, and a first main surface and a second main surface opposite to each other in the Z direction; wherein the X, Y, and Z directions are perpendicular to each other. The periphery of the plate-shaped body has a peripheral sealing portion that connects the edges of the first main surface and the second main surface to form a closed boundary of the cavity; the cavity is provided with a plurality of supporting connecting portions extending along the Z direction and partially connecting the first main surface and the second main surface. The orthographic projection of the supporting connecting portions on the XY plane is arranged in an array at intervals along both the X and Y directions, and the supporting connecting portions in adjacent rows are staggered in the X direction; the portions of the first main surface and the second main surface, except for the areas where the peripheral sealing portion and the supporting connecting portions are located, all protrude outward in mutually distancing directions, forming a plurality of adjacent and interconnected micro-cavities defined by the supporting connecting portions in the cavity. At the same time, the outer surfaces of the first main surface and the second main surface are respectively formed with undulating contours composed of alternating recessed and protruding regions. In the orthographic projection on the XY plane, the projection of the recessed region overlaps with the projection of the supporting connection, the projection of the protruding region covers the projection of the highest region of the micro-chamber, and the sum of the orthographic projection areas of the supporting connection on the XY plane accounts for 1.4~12.6% of the orthographic projection area of ​​the plate-shaped body on the XY plane; the wall thickness difference of the thin shell structure in the protruding region is not greater than 0.5mm; The first end has a cooling medium inlet communicating with the cavity, and the second end has a cooling medium outlet communicating with the cavity, forming a cooling medium flow channel from the first end to the second end; in use, the outer surfaces of the first main surface and the second main surface are in contact with the external mass transfer fluid to form a heat transfer-mass transfer interface; cooling medium flows in the cooling medium flow channel.

[0009] Furthermore, the first main surface and the second main surface are mirror-symmetrical with respect to the mid-plane in the Z direction of the plate-shaped body. The portion of the first main surface, except for the area where the peripheral sealing portion and the support connection portion are located, protrudes outward in the +Z direction. The portion of the second main surface, except for the area where the peripheral sealing portion and the support connection portion are located, protrudes outward in the -Z direction. The sum of the orthographic projection areas of the support connection portion in the XY plane accounts for 4.5 to 5% of the orthographic projection area of ​​the plate-shaped body in the XY plane.

[0010] Furthermore, the orthographic projection of the support connection parts on the XY plane is a staggered diamond array; the center distance between adjacent support connection parts is 10~30mm (referring to the straight-line distance between the geometric centers of adjacent support connection parts); the material of the plate-shaped body is 316L stainless steel, 2205 duplex steel or titanium; in the Z direction, the maximum outline height of the plate-shaped body is 3~9mm.

[0011] Furthermore, the outer surfaces of both the first and second main surfaces are provided with a TiO2-SiO2 superhydrophilic nano-coating, such that the contact angle between the outer surfaces of the first and second main surfaces and water is <5°, and the thickness of the TiO2-SiO2 superhydrophilic nano-coating is 50~500nm.

[0012] Furthermore, in the orthographic projection of the XY plane, both the cooling medium inlet and the cooling medium outlet are located within the first half-width region of the plate-shaped body and are adjacent to the first side portion; wherein, the first half-width region is the half-region of the plate-shaped body in the Y direction defined by the midline between the first side portion and the second side portion, close to the first side portion.

[0013] Furthermore, the outline shape of the protruding region on the orthographic projection of the XY plane is selected from one or more combinations of a circle, an ellipse, or a polygon with ≥3 sides.

[0014] Furthermore, the plate-shaped body is obtained by bonding and welding two thin metal plates together and then inflating them with a high-pressure medium. The thickness of the thin metal plates is 1.0~1.5mm. Method 1 (liquid inflation): the high-pressure medium is demineralized water or rust-preventive liquid, the inflation pressure is 15MPa~35MPa, and the diameter of the support connection is designed to be 4~5mm. Method 2 (gas inflation): the high-pressure medium is high-pressure pure nitrogen, the inflation pressure is 2.0MPa~4.0MPa, and the diameter of the support connection is 2~3mm.

[0015] Alternatively, the plate-shaped body can be integrally formed using an additive manufacturing process, with its internal flow channels directly constructed during the forming process, eliminating the need for the aforementioned blow-up process.

[0016] A second aspect of the present invention is to provide an integrated internal component comprising a plurality of the above-described composite mass transfer heat exchange plate units and a frame for supporting and fixing the composite mass transfer heat exchange plate units. The plurality of composite mass transfer heat exchange plate units are arranged vertically in parallel, and adjacent composite mass transfer heat exchange plate units form an external flow channel for the gas to be treated and the absorbent to flow; the gas to be treated includes, but is not limited to, gas to be desulfurized (H2S) or gas to be decarbonized (CO2), and the absorbent includes, but is not limited to, alcohol amine solutions. The cross-sectional width of the external flow channel is 1 to 2 times the maximum profile height of the plate-shaped body of the composite mass transfer heat exchange plate unit.

[0017] Preferably, the undulating profiles of adjacent composite mass transfer heat exchange plate units are continuous wavy curved surfaces extending in the vertical direction, and the protruding and recessed regions of the two are arranged opposite each other; in the horizontal direction, the vertical spacing between adjacent composite mass transfer heat exchange plate units remains constant in the vertical direction, so that the external flow channel has a uniform cross-sectional width in the vertical direction.

[0018] A third aspect of the present invention is to provide an isothermal desulfurization tower, including a tower body and a cooling medium circulation system; An isothermal desulfurization chamber is formed inside the tower body. The bottom of the tower body is provided with a sulfur-containing gas inlet that communicates with the isothermal desulfurization chamber, and the top of the tower body is provided with a gas outlet that communicates with the isothermal desulfurization chamber. An absorbent spraying device is provided at the top of the isothermal desulfurization chamber, and a drain outlet that communicates with the outside of the tower body is provided at the bottom. The isothermal desulfurization chamber is provided with several sets of the above-mentioned integrated internal components at intervals along the vertical direction. The cooling medium circulation system includes a cooling medium inlet main pipe and a cooling medium outlet main pipe; the cooling medium inlet main pipe is connected to the cooling medium inlet of each composite mass transfer heat exchange plate unit in the integrated internal component through multiple parallel cooling medium inlet branch pipes, and the cooling medium outlet main pipe is connected to the cooling medium outlet of each composite mass transfer heat exchange plate unit in the integrated internal component through multiple parallel cooling medium outlet branch pipes.

[0019] Furthermore, each of the integrated internal components is fixed to the isothermal desulfurization chamber via the frame. The frame includes an upper positioning flange and a lower support flange fixed to the inner wall of the isothermal desulfurization chamber. The upper positioning flange has a comb-shaped limiting groove. The lower support flange includes an annular support portion and a bottom support mesh located inside the annular support portion. The bottom support mesh is made of a grid or wire mesh with through-holes to allow liquid to pass through. The top of each composite mass transfer heat exchange plate unit is inserted into the comb-shaped limiting groove, and the bottom rests against the bottom support mesh. There is a 0.5~1mm movement margin between the sidewall of the comb-shaped limiting groove and the top edge of the composite mass transfer heat exchange plate unit, so as to limit the displacement of the composite mass transfer heat exchange plate unit in the horizontal direction and not hinder the slight movement of the composite mass transfer heat exchange plate unit in the vertical direction. The bottom support net only provides vertical support and does not constrain the longitudinal thermal expansion of the composite mass transfer heat exchange plate unit along its X direction, thus forming a non-rigid connection structure that restricts lateral displacement but allows free longitudinal thermal expansion.

[0020] A fourth aspect of the present invention is to provide a method for gas desulfurization using the above-described isothermal desulfurization tower, comprising the following steps: S1. Cooling medium distribution: Cooling medium is provided to the integrated internals of the isothermal desulfurization tower, so that the cooling medium flows from bottom to top in the cooling medium flow channel inside the plate-shaped body of the composite mass transfer heat exchange plate unit. S2. Absorbent film formation: The absorbent is sprayed from the top of the isothermal desulfurization chamber through the absorbent spraying device, so that the absorbent flows from top to bottom along the outer side of the plate-shaped body of the composite mass transfer heat exchange plate unit, and forms a turbulent absorbent liquid film under the action of the undulating contour. S3. Countercurrent contact: Sulfur-containing gas is introduced from the bottom of the isothermal desulfurization chamber through the sulfur-containing gas inlet, so that it flows from bottom to top in the external flow channel of the integrated internal component and makes countercurrent contact with the absorbent liquid film to carry out mass transfer reaction; S4. In-situ isothermal control: The cooling medium flowing inside the plate-shaped body of the composite mass transfer heat exchange plate unit is used to dynamically remove the heat of reaction at the gas-liquid reaction interface in situ through the wall of the plate-shaped body, thereby controlling the temperature of the absorbent in the isothermal desulfurization chamber to be maintained within the range of 35~45℃ (for amine absorbents, this temperature range usually takes into account both the absorption reaction rate and the acid gas solubility). S5. Product discharge: The clean gas after desulfurization is discharged through the gas outlet at the top of the tower, and the rich liquid after reaction is collected at the bottom of the tower and discharged through the liquid outlet.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects: 1. In-situ isothermal heat removal with uniform wall thickness ensures suppression of interfacial heat accumulation. Existing technologies often employ interstage cooling or external circulation cooling, resulting in spatial separation between the heat exchange surface and the gas-liquid interface, which fails to eliminate instantaneous heat accumulation at the reaction interface. This invention controls the wall thickness variation of the thin-shell structure in the protruding region to ≤0.5mm, ensuring a highly uniform distribution of thermal resistance at the heat exchange-mass transfer interface. This avoids localized excessive thickness leading to thermal resistance islands or excessive thinness causing dry-wall thermal short circuits, ensuring that reaction heat passes through the shell wall into the cooling medium with consistent efficiency, rather than accumulating in the liquid film as micro-temperature peaks. In a typical implementation of the blow forming process, the plate-like body is usually made from a 1.0–1.5mm thick metal sheet as the substrate. After controlling the wall thickness fluctuation to ≤0.5mm on this substrate, the wall thickness of the effective heat exchange-mass transfer region falls within a narrow band of 0.7–1.2mm. For stainless steel shells such as 316L / 2205, the thermal diffusivity is approximately 4×10⁻⁶. -6 m 2 / s, the wall thermal penetration characteristic time is about 0.1 to 1s, and the strong exothermic flux can be conducted away through the thin and uniform wall in a very short time, effectively suppressing the accumulation of local temperature rise in the interfacial micro-elements, and providing a thermal basis for maintaining the absorbent temperature dynamically within a favorable window of 35 to 45℃; with appropriate cooling medium flow rate and spray load design, the absorption operation line can be made close to the low temperature phase equilibrium curve, and the high load zone at the bottom of the tower maintains a high mass transfer driving force, which is conducive to achieving the deep purification index of H2S emission concentration ≤8ppm.

[0022] 2. Synergistic effect of undulating profile and superhydrophilic coating significantly improves effective mass transfer specific surface area: Traditional packed towers rely on the liquid's own gravity for spreading, which easily leads to channeling, wall flow, and dry zones, resulting in insufficient effective mass transfer area. This invention applies a TiO2-SiO2 superhydrophilic nano-coating (contact angle <5°) to the outer surface of the composite mass transfer heat exchange plate unit, synergizing with the undulating profile: The undulating profile acts as a passive turbulence generator, inducing turbulent secondary flow in the liquid film, continuously disrupting the laminar boundary layer, and accelerating the renewal of lean liquid from deep within the liquid phase to the interface; the superhydrophilic coating utilizes surface energy differences to force the liquid film to spread uniformly at the micron scale, suppressing macroscopic channeling and microscopic dry spots. The synergy of these two elements significantly increases the effective contact area, which, at the same desulfurization accuracy, helps to shorten the effective mass transfer height, reduce tower height and floor space, and optimize the absorbent circulation rate (liquid-to-gas ratio) required per unit throughput.

[0023] 3. Parallel flow equalization and non-rigid positioning ensure the operational stability of large-scale equipment. Traditional large desulfurization towers often suffer from internal component deformation due to uneven distribution of cooling medium and limited thermal expansion. This invention uses multiple parallel branch pipes to connect the inlet / outlet main pipe, allowing the cooling medium to flow independently in each plate unit. This avoids the flow rate attenuation at the rear end caused by the accumulation of friction resistance along the series flow channel, ensuring uniform cooling intensity throughout the tower. The comb-shaped limiting groove of the upper positioning flange restricts the lateral displacement of the plates and ensures uniform flow channel width, while not restricting their longitudinal degrees of freedom, allowing the plates to move slightly vertically during temperature fluctuations; the bottom is supported by the lower support flange and support mesh. The combination of parallel flow equalization and non-rigid positioning effectively releases longitudinal thermal stress, significantly reducing the risk of plate warping, weld cracking, and seal failure. While supporting the plates, the support mesh rectifyes and pre-distributes the incoming air through its mesh structure, eliminating bottom eddies and flow deviations. Together with the comb-shaped limiting groove, it forms a high-precision positioning system, ensuring uniform distribution of the gas and liquid phases throughout the entire flow channel.

[0024] 4. The complementary interlocking flow channel configuration achieves a balance between low flow resistance, high stiffness, and resistance to wall flow. Random packing flow channels are chaotic and prone to wall flow, while parallel smooth plate flow channels lack disturbance and sufficient stiffness. This invention constructs a complementary interlocking flow channel that is "macroscopically vertical and microscopically meandering" by aligning the undulating contours of adjacent plates (protrusions against recesses): macroscopically, a constant cross-section is maintained, and the gas exhibits a quasi-horizontal push flow; microscopically, the undulations induce a low-amplitude, smooth deflection of the gas, accompanied by moderate turbulent secondary flow, avoiding the high resistance caused by severe flow deflection and suppressing wall flow and channeling. In terms of mechanical performance, this cross-complementary structure allows the internal support connections of the plates and the undulating walls to work together to bear load, significantly improving the overall deformation resistance of the thin-shell structure under high-pressure conditions and enhancing structural stability under flow-induced vibration. Simultaneously, the continuous deflection of the gas by the wavy walls generates fluid shearing, which helps suppress particulate deposition and scale adhesion, improving the anti-clogging performance of the internal components.

[0025] 5. Dual-track manufacturing process adapts to diverse application scenarios. The core structure of this invention boasts exceptional process compatibility: based on laser welding and high-pressure blowing processes, it can be mass-produced using two thin metal sheets at low cost and high efficiency, suitable for large-scale industrial applications; it also adapts to additive manufacturing processes, replacing weld points with internal solid support meshes to achieve more complex internal flow channel topology optimizations such as density gradients in support connections and variable cross-sections in microcavities, adapting to high-precision or special media scenarios. This dual-track approach ensures broad applicability of this invention in both conventional industrial applications and high-end customized needs. Attached Figure Description

[0026] Figure 1 This is a schematic diagram showing the distribution of local fusion welding points (support connection parts) of the composite slab in Embodiment 1 of this application.

[0027] Figure 2 This is a cross-sectional view of the partial flow channel contour structure of the composite mass transfer heat exchange plate unit in Embodiment 1 of this application.

[0028] Figure 3 This is a schematic diagram of the orthographic projection of the composite mass transfer heat exchange plate unit in Embodiment 1 of this application onto the XY plane.

[0029] Figure 4 This is a schematic diagram of the integrated internal components in Embodiment 2 of this application.

[0030] Figure 5 This is a schematic diagram of the upper positioning flange and the lower support flange in Embodiment 2 of this application.

[0031] Figure 6 This is a schematic diagram of the isothermal desulfurization tower in Embodiment 2 of this application.

[0032] Figure 7This is a schematic diagram of the three-fluid coupling microscopic mass transfer and heat exchange mechanism in the isothermal desulfurization tower in Embodiment 2 of this application.

[0033] In the diagram: 1-Tower body; 11-Isothermal desulfurization chamber; 12-Sulfur-containing gas inlet; 13-Gas outlet; 14-Absorbent spraying device; 15-Drain outlet; 16-Absorbent circulation pump; 17-Flow control valve; 2-Integrated internal components; 21-Composite mass transfer heat exchange plate unit; 211-Plate-shaped body; 2111-First end; 2112-Second end; 2113-First side; 2114-Second side; 2115-First half-width region; 212-Cooling medium flow channel; 213-First main surface; 214-Support connection part; 2141-Recessed region; 215-Micro chamber; 2151-Protruding region; 216-Undulated profile; 217-Cooling medium inlet; 2171-Cooling medium inlet branch pipe; 218-Cooling medium outlet; 2181-Cooling medium outlet branch pipe; 219-Second main surface; 22-Upper positioning flange; 221-Comb-shaped limiting groove; 23-Lower support flange; 231-Annular support part; 232-Bottom support mesh; 3-Cooling medium circulation system; 31-Cooling medium inlet manifold; 32-Cooling medium outlet manifold. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0035] This invention first provides a composite mass transfer heat exchange plate unit, including a plate-shaped body. The plate-shaped body is a thin-shell structure with an internal cavity. It has a first end and a second end opposite to each other in the X direction, a first side and a second side opposite to each other in the Y direction, and a first main surface and a second main surface opposite to each other in the Z direction. The first main surface and the second main surface are mirror-symmetrical with respect to the middle plane of the plate-shaped body in the Z direction. The X, Y, and Z directions are perpendicular to each other. The periphery of the plate-shaped body has a peripheral sealing portion that connects the edges of the first main surface and the second main surface to form a closed boundary of the cavity; the cavity is provided with a plurality of supporting connecting portions extending along the Z direction and partially connecting the first main surface and the second main surface. The orthographic projection of the supporting connecting portions on the XY plane is arranged in an interval array along both the X and Y directions, and the supporting connecting portions in adjacent rows are staggered in the X direction (this staggered arrangement structure is configured so that when the cooling medium flows from the first end to the second end along the X direction, each supporting connecting portion forms a discontinuous staggered turbulence node in the flow channel; compared with the aligned arrangement, the staggered arrangement can induce cooling). The medium generates alternating flow disturbances as it flows through each row of support connections, disrupting the continuous development of the thermal boundary layer on the inner wall of the flow channel and avoiding the stagnation of low-speed wake caused by the overlapping of support connections in the X direction, thereby improving the convective heat transfer coefficient at the wall surface. The first main surface and the second main surface, except for the area where the peripheral sealing part and the support connection part are located, both bulge outward in mutually distancing directions, forming multiple adjacent and interconnected micro-cavities defined by the support connections part in the cavity. At the same time, the outer surfaces of the first main surface and the second main surface are correspondingly formed with undulating contours composed of alternating recessed and protruding regions. In the orthographic projection on the XY plane, the projection of the recessed region overlaps with the projection of the supporting connection, and the projection of the protruding region covers the projection of the highest region of the microcavity (the highest point of the microcavity in the Z direction). The sum of the orthographic projection areas of the supporting connection on the XY plane accounts for 1.4~12.6% of the orthographic projection area of ​​the plate-like body on the XY plane (the physical basis for this area percentage is as follows: the projection area percentage of the supporting connection directly determines the three coupling properties of the plate-like body—structural stiffness, internal flow resistance, and external turbulence intensity. When the percentage is less than 1.4%, there are too few support points, the span between adjacent supporting connections is too large under pressure conditions, and excessive stress concentration occurs at the edge of the supporting connection, which can easily lead to instability, local buckling, or fatigue cracking of the thin-shell structure; at the same time, the external recesses are too sparse, the outer surface is gently undulating, and it is difficult to form effective turbulence when the external gas phase flows through the wall, resulting in a low heat transfer coefficient on the gas film side and poor heat exchange between the wall and the external fluid). Limited heat causes the wall temperature to deviate from the design conditions, resulting in a decrease in mass transfer driving force. When the area ratio exceeds 12.6%, the support connections are too densely arranged, and both internal and external flow channels are excessively throttled, leading to a nonlinear and dramatic increase in fluid resistance. The spacing between external recesses is too small, causing interference and merging between adjacent recirculation zones, forming large-scale periodic shedding vortices instead of small-scale vortices that effectively refresh the boundary layer. This results in a sharp increase in pressure loss, and due to vortex accumulation and energy dissipation caused by flow instability, the mass transfer coefficient no longer increases with the area ratio, leading to a decrease in overall mass transfer efficiency. The 1.4%~12.6% range is a preferred feasible region established among structural safety margin, heat and mass transfer efficiency, and fluid power consumption. The wall thickness difference of the thin-shell structure in the protruding region is no greater than 0.5 mm; that is, in the protruding region, the difference between the maximum and minimum values ​​of the distance measured along the local normal direction of the first main surface between the outer surface of the first main surface and the inner wall of the micro-cavity facing the first main surface does not exceed 0.5 mm. mm; the difference between the maximum and minimum values ​​of the distance between the outer surface of the second main surface and the inner wall of the micro-cavity facing the second main surface, measured along the local normal direction of the outer surface of the second main surface, shall not exceed 0.5 mm (if this difference is not properly controlled and exceeds 0.5 mm, the difference in wall thickness between the thinnest and thickest parts of the protrusion will be too large, resulting in significant uneven local thermal resistance and a decrease in the heat transfer coefficient. Moreover, under pressure, the thinner area will become a weak link in the structure; by limiting this uniformity index, the symmetrical consistency of the wall thickness distribution between the first and second main surfaces can be ensured, thereby achieving a balance in the heat and mass transfer performance on both sides). The first end has a cooling medium inlet communicating with a micro-chamber located at the first end, and the second end has a cooling medium outlet communicating with a micro-chamber located at the second end, forming a cooling medium flow channel from the first end to the second end. In use, the outer surfaces of both the first and second main surfaces of the composite mass transfer heat exchange plate unit of this invention are in contact with external mass transfer fluids (such as absorbent liquid film and the gas to be treated), forming a heat transfer-mass transfer interface. Cooling medium (such as circulating cooling water) is introduced through the cooling medium inlet, distributed through the micro-chamber located at the first end, and flows along the X direction through the interior of the plate-shaped body. After absorbing the heat transferred through the thin wall of the plate-shaped body, it is collected in the micro-chamber located at the second end and discharged through the cooling medium outlet, thereby achieving continuous heat extraction. During this process, as the external mass transfer fluid flows along the undulating contour surface, a local acceleration zone is formed in the protruding region and a local slow-flow zone is formed in the recessed region, enhancing turbulent disturbances near the wall surface. Meanwhile, the cooling medium generates flow disturbances around the staggered support connections in the internal flow channels, disrupting the continuous development of the thermal boundary layer. The synergistic effect of these two factors enables efficient heat exchange between the external mass transfer fluid and the internal cooling medium through the thin wall.

[0036] The composite mass transfer heat exchange plate unit provided by this invention constructs an integrated core architecture of "internal cooling and external heat transfer". By integrating cooling medium channels (micro-cavities) and the undulating contour of the outer surface within a single plate-shaped body, the heat of reaction is rapidly transferred to the internal cooling medium through the thin wall after generation and is immediately carried away, effectively overcoming the inherent defect of heat transfer lag in traditional towers. The specific fit between the support connection array and the main surface (overlapping projections of recessed parts and protrusions covering the highest area of ​​the micro-cavities) does not only serve as structural reinforcing ribs, but also simultaneously acts as the anti-buckling fulcrum of the thin-shell structure, the topological node of the micro-cavities, and the alignment reference for the undulations of the outer surface; combined with the wall thickness uniformity control of "wall thickness difference ≤ 0.5 mm", the risk of local overheating is effectively suppressed and the pressure bearing reliability is improved, providing a uniform geometric basis for efficient mass transfer heat exchange of gas-liquid-coolant.

[0037] According to a preferred embodiment of the present invention, the sum of the projected areas of the supporting connections in the XY plane accounts for 4.5% to 5% of the projected area of ​​the plate-like body in the XY plane. Within this ratio range, the arrangement density of the supporting connections is moderate: it provides sufficient internal pressure stiffness for the plate-like body, avoiding excessive deflection of the plate surface under blowing or pressure conditions; it also prevents excessive frictional resistance in the internal cooling medium flow channels due to overly dense support points, or excessive density of the outer surface recesses, which could lead to a sharp increase in gas phase pressure drop. Simultaneously, the combination of the center distance between adjacent supporting connections and the diameter of the supporting connections at this area ratio ensures that the radius of curvature of the raised areas on the outer surface matches the vortex retention scale of the recessed areas. The turbulent secondary flow formed by the external gas phase as it flows through each row of raised areas can maintain effective intensity before reaching the next row of recesses, thereby maximizing mass transfer enhancement. Experimental verification (see Example 2) shows that the overall mass transfer-pressure drop performance is optimal at this ratio.

[0038] According to embodiments of the present invention, the arrangement of the supporting connections in the orthographic projection on the XY plane is not limited, as long as they form an intermittent array. Preferably, the supporting connections are arranged in a staggered diamond array to obtain uniform support stiffness and flow channel connectivity in all directions. The center distance between adjacent supporting connections (i.e., the distance between the projection centers of two adjacent supporting connections in the XY plane) is 10~30mm; if the center distance is less than 10mm, the micro-cavity volume between adjacent supporting connections is too small, and the resistance to cooling medium flow increases significantly; if the center distance is greater than 30mm, the plate span is too large, and the stress concentration at the edge of the supporting connections is aggravated under pressure, making the plate surface prone to excessive deflection or even local buckling. The plate-shaped body is made of corrosion-resistant metal material, including but not limited to 316L stainless steel, 2205 duplex steel, or titanium, to adapt to corrosive mass transfer environments containing sulfur or chloride ions. In the Z direction, the maximum profile height of the plate-shaped body (i.e., the maximum total thickness of the plate-shaped body in the Z direction) is 3~9mm; if the maximum profile height is less than 3mm, the cross-sectional area of ​​the internal flow channel is too small, the flow rate of the cooling medium is limited, and the heat exchange capacity is insufficient; if it is greater than 9mm, the stability of the thin shell structure under pressure decreases, and the external flow channel undulations are too large, resulting in a significant increase in gas phase resistance.

[0039] According to an embodiment of the present invention, to further improve the wetting performance of the outer surface, the outer surfaces of the first main surface and the second main surface are preferably provided with a superhydrophilic nano-coating. As an example, the superhydrophilic nano-coating is a TiO2-SiO2 composite coating with a thickness of 50~500nm, which can be prepared by the sol-gel method; the static contact angle between the outer surface with the coating and water is less than 5° (measured at room temperature using the seat drop method).

[0040] According to an embodiment of the present invention, in the orthographic projection of the XY plane, both the cooling medium inlet and the cooling medium outlet are located within the first half-width region of the plate-shaped body and are both adjacent to the first side. The first half-width region is the half-area of ​​the plate-shaped body in the Y direction defined by the midline between the first and second sides, closest to the first side. This single-sided centralized layout has two advantages: firstly, the inlet / outlet is confined to one side of the plate-shaped body, which facilitates the smooth filling of each micro-cavity by the cooling medium along the X direction, effectively reducing the "air resistance" and heat exchange dead zones caused by fluid stagnation, and ensuring maximum heat exchange efficiency; secondly, the layout where both the inlet / outlet are adjacent to the first side also simplifies the parallel connection of external pipelines and reduces the difficulty of system integration.

[0041] According to embodiments of the present invention, the outline shape of the protruding region on the orthographic projection of the XY plane is not limited and can be flexibly selected according to actual working conditions. As an example, the outline shape of the protruding region can be a circle, an ellipse, or a polygon with ≥3 sides (such as a triangle, quadrilateral, pentagon, hexagon, etc.), or a combination of the above shapes.

[0042] Furthermore, as an optional embodiment of the present invention, the plate-shaped body is obtained by bonding and welding two thin metal plates together and then inflating them under high pressure. The thickness of the thin metal plates is 1.0~1.5mm (the two thin metal plates are identical, and the thickness refers to the average measured thickness obtained by measuring the flat and undeformed area of ​​the thin metal plate at room temperature using a precision measuring tool).

[0043] Method 1 (Liquid Inflation): The high-pressure medium is demineralized water or rust-inhibiting liquid, and the inflation pressure is 15MPa~35MPa. Due to its large bulk modulus and high system rigidity, the liquid medium facilitates precise pressure control and achieves high dimensional accuracy. To resist the pull-out force caused by the high pressure, the diameter of the support connection is designed to be 4~5mm. As an example, the rust-inhibiting liquid can be a commercially available water-based rust-inhibiting liquid (e.g., a water-based rust-inhibiting solution containing a water-soluble corrosion inhibitor), with a pH value controlled between 8.5 and 10.5 and a conductivity controlled within the range of 500~2000 μS / cm, to balance corrosion resistance and pressure uniformity during the inflation process. The demineralized water can be deionized water.

[0044] Method 2 (Gas Inflation): The high-pressure medium is high-pressure pure nitrogen gas, and the inflation pressure is 2.0MPa~4.0MPa. Because of its low viscosity and lack of residue, the gas medium is suitable for clean environments where liquid contamination must be avoided. In this method, the forming force is smaller, and the diameter of the support connection can be reduced to 2~3mm.

[0045] Alternatively, the plate-shaped body can be integrally formed using an additive manufacturing process, with its internal flow channels directly constructed during the forming process, eliminating the need for the aforementioned blow-up process.

[0046] It should be noted that both welding inflation and additive manufacturing achieve simultaneous fabrication of the microcavity and undulating contour through integral molding, thereby ensuring that the wall thickness difference is ≤0.5mm. This integral molding scheme makes the heat transfer path on both sides of the thin wall continuous and without interfacial thermal resistance, effectively overcoming the heat transfer lag problem caused by the physical separation of the heat exchange interface and mass transfer interface in traditional combined structures.

[0047] Based on the above-mentioned composite mass transfer heat exchange plate unit, the present invention further provides an integrated internal component, including a plurality of the above-mentioned composite mass transfer heat exchange plate units and a frame for supporting and fixing the composite mass transfer heat exchange plate units. The plurality of composite mass transfer heat exchange plate units are arranged vertically in parallel, and adjacent composite mass transfer heat exchange plate units form an external flow channel for the gas to be treated and the absorbent to flow; the gas to be treated includes, but is not limited to, gas to be desulfurized (H2S) or gas to be decarbonized (CO2), and the absorbent includes, but is not limited to, alcohol amine solutions. The cross-sectional width of the external flow channel is 1 to 2 times the maximum profile height of the plate-shaped body of the composite mass transfer heat exchange plate unit.

[0048] The integrated internal components provided by this invention integrate several composite mass transfer heat exchange plate units and arrange them vertically and parallelly through a frame, constructing a standardized mass transfer heat exchange module, which facilitates multi-layer stacking and overall disassembly and maintenance within the tower. The spacing between the plate bodies of adjacent composite mass transfer heat exchange plate units is 1 to 2 times the maximum profile height of the plate body. This size design macroscopically constructs a gas phase flow corridor with a uniform flow cross-section, aiming to balance gas phase resistance and mass transfer efficiency: if the flow channel is too narrow (less than 1 times), the pressure drop will increase sharply due to the gas phase throttling effect and it will be easily blocked by the liquid film; if it is too wide (more than 2 times), the gas velocity will be insufficient to effectively tear the liquid film, easily inducing wall flow and channeling. By controlling the flow channel width within the above range, the effective liquid film coverage and mass transfer area per unit cross-sectional area are maximized while meeting the gas phase flow capacity, and the plate airflow-induced vibration caused by excessively wide channels is prevented. At this flow channel scale, gas can sweep across the undulating profile at a suitable flow rate. The convex structure of the plate-like body continuously shears and refreshes the liquid film, preventing absorbent retention and scaling while keeping the gas phase pressure drop at a low level. This proportional relationship ensures that in the vertically parallel plate bundles, gas can rise smoothly along a constant cross-section, and liquid can form a continuous downward-flowing liquid film on the undulating profile. This effectively avoids the wall flow, channel flow, and flooding phenomena caused by excessively high local gas velocities common in traditional random packings, achieving uniform distribution and efficient contact of the gas and liquid phases on a macroscopic scale.

[0049] According to an embodiment of the present invention, the undulating profiles of adjacent composite mass transfer heat exchange plate units are continuous wavy surfaces extending vertically, with their protruding and recessed regions facing each other. In the horizontal direction, the vertical spacing between adjacent composite mass transfer heat exchange plate units remains consistent along the vertical direction, ensuring a uniform cross-sectional width for the external flow channel. The undulating profiles of the plate-like bodies of adjacent composite mass transfer heat exchange plate units are complementary (protrusions to recesses), macroscopically constructing a gas channel with a constant cross-section. Compared to traditional random packing or randomly arranged plates, this structure eliminates the random contraction and expansion of the flow channel cross-section, making the pressure drop linear and predictable during gas ascent, avoiding eddy energy consumption and vibration caused by sudden changes in local flow velocity. The constant spacing design ensures the self-balancing of gas-liquid distribution: regardless of how the plate-like bodies are manufactured or installed, the gas always flows through the same geometric gap, reducing the risk of gas deviation and local flooding caused by varying flow channel widths.

[0050] Based on the aforementioned integrated internal components, this invention further provides an isothermal desulfurization tower, including a tower body and a cooling medium circulation system; An isothermal desulfurization chamber is formed inside the tower body. The bottom of the tower body is provided with a sulfur-containing gas inlet that communicates with the isothermal desulfurization chamber, and the top of the tower body is provided with a gas outlet that communicates with the isothermal desulfurization chamber. An absorbent spraying device is provided at the top of the isothermal desulfurization chamber, and a drain outlet that communicates with the outside of the tower body is provided at the bottom. The isothermal desulfurization chamber is provided with several sets of the above-mentioned integrated internal components at intervals along the vertical direction. The cooling medium circulation system is used to independently supply cooling medium to each composite mass transfer heat exchange plate unit. It includes a cooling medium inlet main pipe and a cooling medium outlet main pipe. The cooling medium inlet main pipe is connected to the cooling medium inlet of each composite mass transfer heat exchange plate unit in the integrated internal component through multiple parallel cooling medium inlet branch pipes. The cooling medium outlet main pipe is connected to the cooling medium outlet of each composite mass transfer heat exchange plate unit in the integrated internal component through multiple parallel cooling medium outlet branch pipes.

[0051] The isothermal desulfurization tower provided by this invention constructs a segmented countercurrent contact system for gas, liquid, and refrigerant at a macroscopic scale through the vertical spatial layout of the tower body, spray device, and multi-layer integrated internals. The cooling medium circulation system is designed as an independent liquid supply mode of "main pipe – multiple parallel branch pipes – single plate unit." Its core function is to break the cumulative effect of frictional resistance along the flow path in traditional series flow channels, ensuring that each composite mass transfer heat exchange plate unit receives an independent cooling medium supply. Based on this, the multi-layer integrated internals are arranged at intervals along the vertical direction, allowing the reaction heat to be removed segmentally and promptly along the tower height. Combined with the countercurrent flow formed by top spraying and bottom air intake, this ensures a highly uniform temperature field for the absorbent throughout the tower and maintains the desulfurization reaction temperature within the optimal active temperature range (e.g., 35~45℃). This distributed cooling architecture significantly improves heat exchange efficiency without significantly increasing system complexity. Combined with the aforementioned modular frame structure, independent maintenance and replacement of individual plate-shaped units are possible, which is beneficial for maintaining the stability and maintainability of the system during long-term operation.

[0052] According to an embodiment of the present invention, the integrated internals can be configured with composite mass transfer and heat exchange plate units of appropriate width according to the tower diameter, so that a suitable gas-liquid passage gap is left between them and the inner wall of the tower; at the same time, one or more sets of the integrated internals can be arranged in the tower height direction according to the requirements of gas volume and absorption efficiency.

[0053] According to an embodiment of the present invention, each set of integrated internal components is fixed in the isothermal desulfurization chamber by the frame. The frame includes an upper positioning flange and a lower support flange fixed to the inner wall of the isothermal desulfurization chamber. The upper positioning flange has a comb-shaped limiting groove. The lower support flange includes an annular support portion and a bottom support mesh located inside the annular support portion. The bottom support mesh is made of a grid or wire mesh, and its mesh openings are through to allow liquid to pass through. The top of each composite mass transfer heat exchange plate unit is inserted into the comb-shaped limiting groove, and the bottom rests against the bottom support mesh. The sidewall of the comb-shaped limiting groove... There is a 0.5~1mm margin of movement between the composite mass transfer heat exchange plate unit and its top edge to limit the horizontal displacement of the composite mass transfer heat exchange plate unit without hindering its slight vertical movement. The bottom support mesh only provides vertical support and does not restrict the longitudinal thermal expansion of the composite mass transfer heat exchange plate unit along its X direction, thus forming a non-rigid connection structure that restricts lateral displacement but allows free longitudinal thermal expansion. Through the cooperation of the comb-shaped limiting groove of the upper positioning flange and the lower support flange, a constraint system of "vertical support, horizontal limitation, and longitudinal release" is constructed. The comb-shaped limiting grooves apply lateral constraints to the top of the composite mass transfer heat exchange plate unit, effectively resisting the swaying and torsion caused by airflow pulsation and its own gravity, ensuring the verticality of the plate bundle and the geometric accuracy of the flow channel cross-section. The grid structure of the bottom support mesh forms uniform air permeable pores on the cross-section of the tower, which can play a primary rectification and uniform distribution role for the sulfur-containing gas entering from the bottom of the tower, forcing the gas to be evenly dispersed to the inlet cross-section of each external flow channel, eliminating local high-speed jets or dead zones at the bottom, and further ensuring the balance of gas-liquid mass transfer. In addition, the groove structure does not restrict the vertical degree of freedom of the plate body, thus physically decoupling the thermal expansion stress: when a temperature difference is formed between the cooling medium and the process gas inside and outside the plate body, the composite plate can freely expand and contract in the vertical direction, avoiding the risk of bending stress or weld cracking caused by rigid clamping. In addition, this plug-in non-rigid connection effectively simplifies the installation and alignment of internal components of large tower equipment. Each plate-shaped body can slide into position independently along the comb-shaped limiting groove, and can be removed and replaced individually during maintenance without dismantling the overall frame, which significantly reduces maintenance costs and maintenance downtime.

[0054] The present invention will be described in detail below with reference to specific embodiments, but this does not limit the present invention.

[0055] Example 1: Precision manufacturing and microstructure construction of composite mass transfer heat exchange plate unit This embodiment is combined with the appendix Figures 1-3The laser welding-high pressure medium blowing process and structural features of the composite mass transfer heat exchange plate unit 21 are described in detail. A thin metal plate of the same material is used as the substrate (in this embodiment, a rectangular plate is used exemplarily), with a single sheet thickness of 1.0 mm to 1.5 mm, and the material is 316L stainless steel or titanium.

[0056] (1) Blank preparation and stacking positioning: Take two rectangular metal sheets of the same size, align the edges of the two sheets and stack them to form a composite blank to be welded, ensuring that there are no foreign objects or misalignments on the stacking surface of the two sheets.

[0057] (2) Peripheral sealing welding and interface reservation: High-energy laser welding technology is used to continuously seal the edges of the composite slab to form a peripheral sealing part located at the periphery of the composite slab, thereby sealing the overlapping gap between the two metal sheets into a sealed cavity to be inflated; during the welding process, at the preset position ( Figure 3 The first end 2111 of the first side portion 2113 has a notch that extends through to the cavity to be inflated to form a cooling medium inlet 217; correspondingly, the second end 2112 has a notch that extends through to the cavity to be inflated to form a cooling medium outlet 218; at the same time, a Φ3mm to Φ6mm inflating process hole is reserved at one corner of the peripheral sealing portion for subsequent high-pressure medium injection.

[0058] (3) Welding of the supporting connection in the middle area: After completing the welding of the peripheral sealing part, weld the main plane of the composite slab as follows: Figure 1 The diagram shows the supporting connection 214, which consists of two thin metal plates intersecting and fused together at corresponding positions in a diamond-shaped array. The diameter of the supporting connection 214 is 2-5 mm (4-5 mm when using liquid inflation, and 2-3 mm when using gas inflation), and the center distance between adjacent supporting connection 214 is 10 mm-30 mm. By matching the diameter of the supporting connection 214 and the center distance between adjacent supporting connection 214, the sum of the orthographic projection areas of the supporting connection 214 on the XY plane accounts for 1.4%-12.6% of the orthographic projection area of ​​the area enclosed by the periphery sealing part of the composite slab. After inflation, the supporting connection 214 remains fused and does not participate in plastic deformation. After welding is completed, before the inflation process, a removable pressure-resistant sealing plug is used to temporarily seal the cooling medium inlet 217 and the cooling medium outlet 218 to ensure that no leakage occurs when the high-pressure medium is injected into the cavity.

[0059] (4) Limiting Inflation and Synchronous Forming: The composite slab is placed between two limiting plates and clamped and fixed with external clamps; the working surface distance between the two limiting plates is set to 3mm to 9mm. High pressure medium (high pressure liquid (deionized water / rust inhibitor) with a pressure of 15MPa to 35MPa or high pressure pure nitrogen with a pressure of 2.0MPa to 4.0MPa) is introduced into the cavity to be inflated inside the composite slab through the inflation process hole. Under the action of high pressure medium, the two metal sheets, except for the periphery sealing part and the support connection part 214 of the composite slab, bulge outward and undergo plastic deformation. After inflation and pressure holding to shape, the pressure is released, the high pressure medium inside the composite slab is discharged, and dry gas (preferably nitrogen, but hot air can also be used) is introduced into the cavity through the process hole for purging and drying; then the cooling medium inlet 217 and the cooling medium are removed. The pressure-resistant sealing plug at the liquid outlet 218 forms a plate-shaped body 211. Through the synergy of the above three factors—"incoming material thickness tolerance control, hard constraint of the limiting template, and uniformity guarantee of the weld point array"—the wall thickness difference in the protruding area can be stably controlled within ≤0.5mm. Precisely controlled incoming material thickness tolerance ensures that the initial wall thickness of each area is consistent. The uniform weld point array ensures that the deformation boundary conditions of each bulge area are consistent. The limiting template, through hard constraint on the maximum contour height, limits the wall thickness reduction of each area to the same upper limit, thereby ensuring that the wall thickness difference of different protruding areas within the same plate-shaped body 211 meets the aforementioned requirement of ≤0.5mm.

[0060] (5) Superhydrophilic surface modification: The outer surface of the obtained plate-shaped body 211 was modified to be superhydrophilic. A TiO2-SiO2 nanocomposite coating with a thickness of 50~500nm was coated by sol-gel method and cured by low temperature baking at 120℃. The contact angle of the modified outer surface is less than 5°, ensuring that the absorbent can be fully spread on the undulating contour 216 of the outer surface of the plate-shaped body 211 even at low spray density, eliminating dry spots and groove phenomena.

[0061] (6) Final assembly and sealing: Connect the cooling medium inlet 217 and cooling medium outlet 218 to the external pipeline through the pipe fitting, and seal the interface by butt welding or fillet welding; finally, use laser welding to seal the blow-up process hole to ensure the overall flow channel sealing and obtain the composite mass transfer heat exchange plate unit.

[0062] The structure of the resulting composite mass transfer heat exchange plate unit is as follows: Figure 2 , Figure 3As shown, specifically, the composite mass transfer heat exchange plate unit includes a plate-shaped body 211 (a thin-shell structure with an internal cavity), which has a first end 2111 and a second end 2112 opposite to each other in the X direction, a first side portion 2113 and a second side portion 2114 opposite to each other in the Y direction, and a first main surface 213 and a second main surface 219 opposite to each other in the Z direction. The first main surface 213 and the second main surface 219 are mirror-symmetrical with respect to the middle plane of the plate-shaped body 211 in the Z direction; the X, Y, and Z directions are perpendicular to each other. The plate-shaped body 211 has a peripheral sealing portion (not shown in the figure) that connects the edges of the first main surface 213 and the second main surface 219 to form a closed boundary of the cavity; the cavity is provided with a plurality of support connecting portions 214 extending along the Z direction and partially connecting the first main surface 213 and the second main surface 219, the orthographic projection of the support connecting portions 214 on the XY plane is arranged in a diamond array; the part of the first main surface 213 except for the area where the peripheral sealing portion and the support connecting portion 214 are located protrudes outward along the +Z direction, the second main surface 213... Except for the area where the peripheral sealing part and the support connection part 214 are located, the part of 19 protrudes outward along the -Z direction, forming a plurality of adjacent and interconnected micro-cavities 215 defined by the support connection part 214 in the cavity. At the same time, the outer surfaces of the first main surface 213 and the second main surface 219 are respectively formed with an undulating profile 216 composed of alternating recessed regions 2141 and protruding regions 2151; and a TiO2-SiO2 superhydrophilic nano-coating with a thickness of 50~500nm is formed on all the outer surfaces of the undulating profile 216. In the orthographic projection on the XY plane, the projection of the recessed region 2141 overlaps with the projection of the support connection 214, and the projection of the protruding region 2151 covers the projection of the highest region of the microcavity 215. The sum of the orthographic projection areas of the support connection 214 on the XY plane accounts for 1.4 to 12.6% of the orthographic projection area of ​​the plate-shaped body 211 on the XY plane. At the protruding region 2151, the difference between the maximum and minimum values ​​of the distance between the outer surface of the first main surface 213 and the inner wall of the microcavity 215 facing the first main surface 213 along the local normal direction of the outer surface of the first main surface 213 does not exceed 0.5 mm. The difference between the maximum and minimum values ​​of the distance between the outer surface of the second main surface 219 and the inner wall of the microcavity 215 facing the second main surface 219 along the local normal direction of the outer surface of the second main surface 219 does not exceed 0.5 mm. The first end 2111 has a cooling medium inlet 217 communicating with the micro-chamber 215 located at the first end 2111, and the second end 2112 has a cooling medium outlet 218 communicating with the micro-chamber 215 located at the second end 2112. The cooling medium inlet 217 and the cooling medium outlet 218 are both located in the first half-width region 2115 of the plate-shaped body 211 near the first side portion 2113, and are both located adjacent to the first side portion 2113, forming a cooling medium flow channel 212 from the first end 2111 to the second end 2112.

[0063] This embodiment employs a structure consisting of two opposing thin metal plates connected together, with peripheral sealing welding and arrayed weld point support, and is formed by high-pressure medium blowing. Compared to the traditional process of stamping first and then welding, this method eliminates the deep bottom corner dead zone and fitting gaps often associated with stamping grooves. The inner wall of the flow channel is generated by continuous plastic deformation, with continuous curvature, making it less prone to geometric dead corners. Combined with the constraint of limiting plates set on both sides during the blowing process, the wall thickness reduction can be stably controlled, ensuring reproducibility in industrial mass production.

[0064] In other embodiments, the composite mass transfer heat exchange plate unit 21 can also be integrally formed using additive manufacturing (3D printing). Specifically, 316L stainless steel or titanium alloy powder can be used as raw material, and selective laser melting (SLM) equipment can be used to print layer by layer according to a preset digital model. During the printing process, the cooling medium flow channels 212 and the arrayed support connections 214 are directly formed internally, while the undulating contour 216 is formed externally. After printing, stress-relief annealing and surface polishing are performed, and the aforementioned TiO2-SiO2 superhydrophilic nano-coating is coated. This alternative process can also achieve the integral integration of the internal cooling channels and the external undulating contour, and is suitable for small-batch customized scenarios.

[0065] Example 2: Modular Array Assembly and Thermal Stress Management This embodiment combines Figures 4-6 This paper details the integrated internal component 2 and the specific implementation structure of the isothermal desulfurization tower of the present invention. This embodiment is based on the composite mass transfer and heat exchange plate unit 21 prepared in Embodiment 1, and focuses on its modular integration, fluid distribution, thermal stress release mechanism and operation control logic in large industrial towers.

[0066] (1) Non-rigid assembly of integrated internal component 2 See Figures 4-6 Several composite mass transfer heat exchange plate units 21 are integrated into an integrated internal component 2 through a frame. Several composite mass transfer heat exchange plate units 21 are arranged vertically and parallel, and adjacent composite mass transfer heat exchange plate units 21 form an external flow channel for the gas to be treated and the absorbent to flow. The frame includes an upper positioning flange 22 and a lower support flange 23, which are coaxially fixed to the inner wall of the isothermal desulfurization chamber 11 of the isothermal desulfurization tower.

[0067] like Figure 5 As shown, the upper positioning flange 22 has a comb-shaped limiting groove 221, and the lower support flange 23 includes an annular support portion 231 and a bottom support mesh 232 located inside the annular support portion. The bottom support mesh 232 is made of grid or wire mesh, with through-holes to allow liquid to pass through. During assembly, the top of each composite mass transfer heat exchange plate unit 21 is inserted into the comb-shaped limiting groove 221, and the bottom rests on the bottom support mesh 232. There is a 0.5~1mm movement margin between the sidewall of the comb-shaped limiting groove 221 and the top edge of the composite mass transfer heat exchange plate unit 21 to limit the horizontal displacement of the composite mass transfer heat exchange plate unit 21, and not to hinder the slight vertical movement of the composite mass transfer heat exchange plate unit 21. The bottom support mesh 232 only provides vertical support force and does not restrict the longitudinal thermal expansion of the composite mass transfer heat exchange plate unit 21 along its X direction, thereby forming a non-rigid connection structure that restricts lateral displacement but allows free longitudinal thermal expansion.

[0068] (2) Construction of constant cross-section flow channel and uniform airflow distribution like Figure 6 As shown, the isothermal desulfurization tower includes a tower body 1 and a cooling medium circulation system 3; an isothermal desulfurization chamber 11 is formed inside the tower body 1, and a sulfur-containing gas inlet 12 connected to the isothermal desulfurization chamber 11 is provided at the bottom of the tower body 1, and an outlet 13 connected to the isothermal desulfurization chamber 11 is provided at the top; an absorbent spraying device 14 is provided at the top of the isothermal desulfurization chamber 11, and a drain outlet 15 connected to the outside of the tower body 1 is provided at the bottom; The isothermal desulfurization chamber 11 is provided with several sets of integrated internal components 2 in this embodiment (1) at intervals along the vertical direction; See Figure 6 The assembled integrated internal components 2 are inserted vertically at intervals into the isothermal desulfurization chamber 11 inside the isothermal desulfurization tower (in this embodiment, only one set of integrated internal components 2 is included).

[0069] Flow channel configuration: The undulating profile 216 of adjacent composite mass transfer heat exchange plate units 21 are both continuous wavy curved surfaces extending in the vertical direction, and the protruding regions 2151 and the recessed regions 2141 of the two are arranged opposite each other; in the horizontal direction, the vertical spacing between adjacent composite mass transfer heat exchange plate units 21 is consistent in the vertical direction, so that the external flow channel has a uniform cross-sectional width in the vertical direction.

[0070] Flow channel width ratio: The vertical spacing between adjacent composite mass transfer heat exchange plate units 21 constitutes the effective cross-sectional width of the external flow channel, which is 1 to 2 times the maximum profile height (3mm~9mm) of the plate body 211 in the Z direction. For example, when the maximum profile height of the plate body 211 is 6mm, the vertical spacing between adjacent composite mass transfer heat exchange plate units 21 can be set to 6mm~12mm (e.g., 8mm~10mm, to balance gas flow rate and mass transfer efficiency). This range ensures that the cross-sectional area of ​​the external flow channel is sufficient to maintain gas flow rate and control pressure drop, while avoiding the risk of blockage due to excessively narrow flow channels or the decrease in mass transfer efficiency due to excessively wide flow channels.

[0071] Fluid dynamics mechanism: When gas flows along the plate surface, the undulating profile 216 generates a pressure gradient along the lateral direction due to the change in wall curvature, thereby inducing turbulent secondary flow in the near-wall liquid film region. This turbulent secondary flow promotes liquid film surface renewal and increases the mass transfer rate. At the same time, through the converging effect of the valley region (recessed region 2141) of the undulating profile, the liquid film is kept within a controllable thickness range. When the width of the external flow channel is 1 to 2 times the maximum profile height of the plate-shaped body, it can enhance interface renewal while avoiding excessive thinning, rupture, or removal of the liquid film due to airflow shear.

[0072] Uniform airflow distribution: The grid structure of the bottom support mesh 232 forms uniform air permeable pores on the cross-section of the tower body, which plays a primary role in rectifying and distributing the sulfur-containing gas entering from the bottom of the tower, guiding the gas to be evenly dispersed to each external flow channel, and effectively reducing the dead zone at the bottom.

[0073] (3) Cooling medium circulation system See Figures 5-6 The cooling medium circulation system 3 adopts a distributed parallel liquid supply architecture (i.e., the liquid supply mode of "main pipe - multiple parallel branch pipes - single plate unit"), including the cooling medium inlet main pipe 31 and the cooling medium outlet main pipe 32. Liquid inlet path: The cooling medium inlet main pipe 31 is directly connected to the cooling medium inlet 217 (located at the first end 2111, i.e. below) of each composite mass transfer heat exchange plate unit 21 through multiple parallel cooling medium inlet branch pipes 2171.

[0074] Liquid outlet path: The main outlet pipe 32 of the cooling medium is directly connected to the cooling medium outlet 218 (located at the second end 2112, i.e. above) of each composite mass transfer heat exchange plate unit 21 through multiple parallel cooling medium outlet branch pipes 2181.

[0075] This parallel architecture breaks the cumulative effect of frictional resistance in traditional series flow channels, ensuring that the cooling pressure and flow rate of each plate are highly consistent.

[0076] (4) Desulfurization operation and in-situ isothermal control (in conjunction with microscopic mechanisms) Based on the above isothermal desulfurization tower, the following steps are used for the desulfurization treatment of high-sulfur natural gas (gas to be treated: high-acid natural gas with H2S content of 3.5 vol%; absorbent: 30~35 wt% MDEA (methyldiethanolamine) aqueous solution (high viscosity); cooling medium: demineralized water at 25~30℃). Figure 7 This is a schematic diagram of the three-fluid coupling microscopic mass transfer and heat exchange mechanism in an isothermal desulfurization tower. In the diagram, the red arrows represent the direction of reaction heat transfer, the blue arrows represent the overall flow direction of the cooling medium, and the black arrows represent the flow direction of the absorbent liquid film. S1. Cooling medium distribution: Cooling medium is provided to the integrated internal component 2 in the isothermal desulfurization tower, so that the cooling medium flows from bottom to top in the cooling medium flow channel 212 inside the plate-shaped body 211 of the composite mass transfer heat exchange plate unit 21.

[0077] S2. Absorbent film formation: The absorbent is sprayed from the top of the isothermal desulfurization chamber 11 through the absorbent spraying device 14, such as... Figure 7 As shown, the high-viscosity absorbent flows from top to bottom along the plate surface under the synergistic effect of gravity and the undulating contour 216 with a superhydrophilic nano-coating on its surface. It spreads on the undulating contour 216 on the outer surface of the plate-shaped body 211, and forms a geometric liquid-guiding channel in the recessed region 2141 of the undulating contour 216, making the flow distribution more uniform, suppressing channeling, and forming a turbulent absorbent liquid film with uniform thickness and dynamic renewal (actual measurement shows that the liquid film thickness is about 0.3mm~0.5mm). Unlike the channeling phenomenon in traditional packed towers, the absorbent liquid film in this embodiment generates stable micro-turbulence induced by the undulating contour 216 in the gravity flow, continuously breaking the liquid phase mass transfer boundary layer, causing the lean liquid component to continuously surge from the depth of the liquid film to the gas-liquid interface, maintaining a high amine concentration and mass transfer driving force at the interface.

[0078] S3. Countercurrent contact: High-acid natural gas is introduced from the bottom of the isothermal desulfurization chamber 11 through the sulfur-containing gas inlet 12, so that it flows from bottom to top in the external flow channel of the integrated internal component 2 and has a countercurrent contact with the absorbent liquid film to carry out mass transfer reaction: H2S molecules diffuse from the gas phase through the gas-liquid interface into the absorbent liquid film, and have an instantaneous chemical reaction with the absorbent and release a large amount of heat.

[0079] S4. In-situ isothermal control (core mechanism): such as Figure 7As shown, the cooling medium flowing within the cooling medium channel 212 inside the plate-shaped body 211 of the composite mass transfer heat exchange plate unit 21 rapidly removes the heat of reaction after it is generated by passing through the extremely thin metal wall (with minimal thermal resistance) perpendicular to the plate surface (i.e., the local normal direction) in situ. Due to the continuous flow of the cooling medium, efficient counter-current heat exchange is formed. By real-time monitoring of the cooling medium temperature at the outlet 218 of each composite mass transfer heat exchange plate unit 21 and interlocking the adjustment of the total cooling medium flow rate, the liquid phase temperature of the entire tower is stably controlled within the range of 35℃ to 45℃, as shown by online temperature monitoring. This near-isothermal operating environment effectively suppresses the tendency of the equilibrium partial pressure of H2S in the amine solution to increase with temperature, thereby maintaining the maximum mass transfer driving force between gas and liquid (studies show that for commonly used alcohol amine absorbents (such as MDEA formulation solution), 35~45℃ is the best temperature range that balances absorption rate and saturation capacity; if the temperature is higher than this range, the solubility of acid gas decreases and the desulfurization efficiency decreases; if the temperature is lower than this range, the viscosity of the absorbent increases and the fluidity and mass transfer performance decrease).

[0080] S5. Product discharge: The clean gas after desulfurization is discharged through the gas outlet 13 at the top of the tower, and the rich liquid after reaction is collected at the bottom of the tower and discharged through the liquid outlet 15.

[0081] Furthermore, such as Figure 6 As shown, the isothermal desulfurization tower is also equipped with an absorbent circulation system, including an absorbent circulation pump 16 and a flow control valve 17. The rich liquid after reaction discharged through the drain port 15 in S5 can be transported back to the top of the tower through an external pipeline driven by the absorbent circulation pump 16. After the flow rate is adjusted by the flow control valve 17, it is sprayed again onto the integrated internal component 2 by the absorbent spraying device 14, realizing the recycling of the absorbent. By adjusting the opening of the flow control valve 17, the spraying density can be adjusted in real time according to the inlet gas load and H2S concentration, thereby controlling the absorbent circulation volume and reducing energy consumption while ensuring desulfurization efficiency.

[0082] Application Example 1 Based on the composite mass transfer and heat exchange plate unit 21 in Example 1 and the integrated internal component 2 and isothermal desulfurization tower in Example 2, an isothermal desulfurization tower with an inner diameter of 0.8m and a total height of 6m is constructed.

[0083] The tower body 1 is made of 316L stainless steel with a wall thickness of 10mm. The core mass transfer functional area of ​​the isothermal desulfurization chamber 11 consists of an integrated internal component 2 with a height of 1.5m, integrating 39 composite mass transfer heat exchange plate units 21 formed by high-pressure blowing. Each composite mass transfer heat exchange plate unit 21 is formed by laser welding and high-pressure medium blowing of two 1.0mm thick and 1.5m long metal plates. To adapt to the circular tower cross-section, the width of each composite mass transfer heat exchange plate unit 21 is arranged in a gradient along the chord of the tower body. The maximum width of the composite mass transfer heat exchange plate unit in the central area is 0.78m. The diameter of the support connection part 214 is 4mm, and the center distance between adjacent support connection parts 214 is 30mm. The sum of the orthographic projection areas of the support connection parts on the XY plane is calculated. The plate-shaped body occupies 1.4% of the projected area of ​​the plate-shaped body on the XY plane. High-pressure liquid inflation is performed using demineralized water at a pressure of 18 MPa. The maximum profile height of the composite mass transfer heat exchange plate unit 21 after inflation is 8 mm, and the wall thickness of the protruding area is 0.70~0.80 mm. Under this structure of the composite mass transfer heat exchange plate unit 21, due to the significant reduction in internal flow resistance points of the plate-shaped body 211, the effective flow rate of the internal cooling medium channel 212 reaches its maximum, and the undulating profile 216 of the outer surface of the plate-shaped body 211 is relatively smooth. The outer surface of the plate-shaped body 211 is coated with a 200 nm thick TiO2-SiO2 superhydrophilic nano-coating using a sol-gel method and then cured at a low temperature of 120℃. Supported and fixed by the upper positioning flange 22 and the lower support flange 23, a regular space of 12mm is constructed between adjacent composite mass transfer heat exchange plate units 21 for the gas to be treated (sulfur-containing natural gas with H2S concentration of 3500ppm) and the absorbent (30wt% MDEA aqueous solution, temperature 38℃, circulation rate 15m³). 3 The external flow channel for the cooling medium circulation system 3 is 25℃ demineralized water as the cooling medium. The cooling medium inlet main pipe 31, cooling medium inlet branch pipe 2171, cooling medium outlet main pipe 32 and cooling medium outlet branch pipe 2181 are all made of DN65 stainless steel, realizing the distributed parallel transportation of the cooling medium in the cooling medium flow channel 212 inside the 39 composite mass transfer heat exchange plate units 21, ensuring the cooling uniformity of each composite mass transfer heat exchange plate unit 21.

[0084] Operating conditions: 2000 Nm 3At an operating pressure of 2.5 MPa, a 150-hour full-load continuous operation test was conducted. During this test, the total gas phase pressure drop was only 0.035 MPa, and the energy consumption of the induced draft fan was at its lowest level. Regarding thermodynamics and mass transfer performance, due to the relatively mild micro-turbulence intensity, the turbulent secondary flow of the liquid film near the wall region had a slightly slower refresh rate of the thermal boundary layer. The measured transient temperature control thermal response time of the system was approximately 450 ms. The local temperature of the absorbent liquid film throughout the tower was maintained within the range of 43℃ to 45℃. Although the thermal response speed met the requirements of conventional processes, the mass transfer driving force did not reach its limit. Ultimately, the measured H2S emission concentration at the top of the tower was 8 ppm, with a desulfurization efficiency ≥99.8%, meeting the emission standards for deep desulfurization.

[0085] Application Example 2 This application embodiment is basically the same as application embodiment 1, except that: the center distance between adjacent support connection parts 214 is 16mm. According to calculation, the sum of the orthographic projection areas of the support connection parts on the XY plane accounts for 4.9% of the orthographic projection area of ​​the plate-shaped body on the XY plane. This arrangement achieves a perfect engineering balance between structural mechanical strength and fluid mechanical resistance; high-pressure liquid inflation is performed using demineralized water with a pressure of 22MPa; the maximum profile height of the composite mass transfer heat exchange plate unit 21 after inflation is 6mm, the wall thickness of the protruding area is 0.70~0.80mm, and the spacing of the external flow channels is 9mm.

[0086] Operating conditions: 2000 Nm 3 Under an operating pressure of 2.5 MPa, a 150-hour full-load continuous operation test was conducted. During this test, the total gas phase pressure drop remained consistently at an excellent level of 0.05 MPa. The energy consumption of the induced draft fan increased only slightly by about 5% compared to Application Example 1, demonstrating extremely high engineering economics. In terms of mass transfer and thermal response, the 4.9% area ratio and undulating profile created a strong synergistic coupling effect at the microscale, forcibly guiding the refrigerant inside the plate and the liquid film outside the plate to generate turbulent secondary flow. The transient temperature control thermal response time was significantly compressed to about 160 ms. The extremely thin physical wall surface coupled with extremely high heat transfer efficiency successfully locked the temperature field of the liquid phase reaction interface of the entire tower within the optimal high-activity temperature range of 38℃~42℃, thermodynamically suppressing the increase of H2S equilibrium partial pressure. Ultimately, the H2S emission concentration at the top of the tower was 5 ppm, and the desulfurization efficiency was ≥99.8%, meeting the emission standards for deep desulfurization.

[0087] Application Example 3 This application embodiment is basically the same as application embodiment 1, except that: the center distance between adjacent support connection parts 214 is 10mm; the sum of the orthographic projection areas of the support connection parts on the XY plane is calculated to account for 12.6% of the orthographic projection area of ​​the plate-shaped body on the XY plane; high-pressure liquid inflation is performed using demineralized water with a pressure of 28MPa; the maximum profile height of the composite mass transfer heat exchange plate unit 21 after inflation is 6mm, the wall thickness of the protruding area is 0.80~0.90mm, and the spacing of the external flow channels is 9mm.

[0088] Operating conditions: 2000 Nm 3 A 150-hour full-load continuous operation test was conducted at an operating pressure of 2.5 MPa. During this test, the extremely high-density undulating profile acted as a powerful passive turbulence generator, thoroughly and frequently tearing the heat transfer boundary layer. The transient temperature control thermal response time of the system was shortened to an extreme level of approximately 100 ms. The temperature field across the entire tower was maintained uniformly within the range of 36~38℃. Under extreme mass transfer driving force, the H2S emission concentration at the top of the tower was further reduced to 4 ppm, and the desulfurization efficiency was ≥99.8%, meeting the emission standards for deep desulfurization. However, due to the excessively tortuous internal flow channels and the severe radial throttling of the external flow channels by the high-density recessed region, the hydrodynamic performance deteriorated. The total gas phase pressure drop of the system surged to approximately 0.08 MPa, and the shaft power energy consumption of the induced draft fan increased by approximately 18% compared to Application Example 1, resulting in a decrease in overall economic efficiency during large-scale, long-cycle industrial operation.

[0089] During 150 hours of full-load operation, no pressure drop drift or scaling / clogging was observed in Application Examples 1-3, verifying the stability and anti-clogging ability of the integrated internal component 2 in long-term operation.

[0090] Comparative Example 1 (A horizontal comparison between the present invention and a traditional random packed tower) A DN80 Pall ring random packing tower was used as a comparative example for testing. The packing layer height of the random packing tower was 1.5m, which is consistent with the height of the mass transfer functional area of ​​the integrated internal component 2 in Application Example 1. The rest of the tower structure and the arrangement of gas and liquid inlets and outlets were consistent with Application Example 1.

[0091] The results of the 150-hour continuous full-load operation comparison test are as follows: Regarding purification indicators, the control tower using DN80 Pall ring random packing maintained a stable H2S concentration of 12-15 ppm at the top outlet, failing to consistently meet the emission standards for deep desulfurization (≤8 ppm). Analysis suggests that the random packing tower exhibits significant channeling and wall flow phenomena in the gas-liquid two-phase flow, resulting in poor liquid distribution uniformity and ineffective wetting of some packing areas, leading to a significantly lower effective mass transfer area than the theoretical value.

[0092] In terms of energy consumption and hydrodynamic performance, the measured total pressure drop of the random-packed tower is approximately 0.10~0.12 MPa, significantly higher than that of Application Examples 1~3. Although the random-packed material has a high specific surface area, its airflow channels are randomly tortuous, resulting in high gas flow resistance. Consequently, the energy consumption of the matching fan is approximately 20~25% higher than that of the scheme in Application Example 1.

[0093] Regarding temperature control, the lack of in-situ heat removal capacity in random-packed towers means that the heat released by the absorption reaction cannot be removed in time, leading to a local temperature rise of 50-60°C in the absorbent liquid film within the tower, especially forming obvious hot spots in the lower and middle packing layers. This temperature rise reduces the equilibrium solubility of H2S in the MDEA aqueous solution, further worsening the mass transfer driving force and making it difficult to consistently achieve the required H2S concentration at the outlet. In contrast, the present invention utilizes a composite mass transfer heat exchange plate unit with a built-in cooling medium flow channel 212 to achieve in-situ dynamic removal of the reaction heat, ensuring that the overall tower temperature is stably controlled within the range of 35-45°C, thus thermodynamically guaranteeing the continuous and efficient desulfurization reaction.

[0094] Regarding operational stability and anti-fouling performance, the random-packed tower exhibited significant pressure drop drift in the later stages of operation (the pressure drop gradually increased from the initial 0.08 MPa to over 0.11 MPa). Disassembly and inspection revealed localized blockage and liquid phase retention within the packing layer. In contrast, the regular parallel plate flow channel structure in the present invention described in Examples 1-3 showed no pressure drop drift or scaling / clogging during 150 hours of full-load operation, verifying its excellent anti-fouling performance.

[0095] The integrated internal components and isothermal desulfurization tower provided by this invention are significantly superior to traditional random packing tower solutions in terms of purification efficiency, energy consumption level, temperature control and operational stability, reflecting the comprehensive technical advantages brought about by the triple synergy of "mass transfer enhancement - in-situ heat removal - flow channel regularization".

[0096] Comparative Example 2 (Support connection parts are too densely arranged: center distance 8mm, area ratio 19.6%) This comparative example is basically the same as Application Example 1, except that: the center distance between adjacent support connection parts 214 is 8mm. According to calculation, the sum of the orthographic projection areas of the support connection parts on the XY plane accounts for 19.6% of the orthographic projection area of ​​the plate-shaped body on the XY plane; high-pressure liquid inflation is performed using demineralized water at a pressure of 32MPa; the maximum profile height of the composite mass transfer heat exchange plate unit 21 after inflation is 4mm, and the wall thickness of the protruding area is 0.80~0.90mm. This structure causes the flow cross section of the internal micro-cavity to be severely compressed; the spacing of the external flow channels is 5mm.

[0097] Operating conditions: 2000 Nm3 At an operating pressure of 2.5 MPa, a 150-hour full-load continuous operation test was conducted. During this test, the external undulation profile was excessively dense, resulting in severe ineffective vortices in the airflow within the external channel. The total gas phase pressure drop surged to over 0.15 MPa, significantly increasing the energy consumption of the induced draft fan. The extremely high gas phase resistance induced severe local flooding, disrupting the stability of the gas-liquid countercurrent contact and causing a severe deterioration in mass transfer throughout the tower. The H2S emission concentration at the top of the tower rebounded to 22 ppm (completely deviating from the ≤8 ppm requirement), completely negating the economic viability of deep desulfurization.

[0098] Comparative Example 3 (Support connection parts are too sparsely arranged: center distance 32mm, area ratio 1.2%) This comparative example is basically the same as Application Example 1, except that: the center distance between adjacent support connection parts 214 is 32mm; the sum of the orthographic projection areas of the support connection parts on the XY plane is calculated to account for 1.2% of the orthographic projection area of ​​the plate-shaped body on the XY plane; high-pressure liquid inflation is performed using demineralized water at a pressure of 15MPa; the maximum profile height of the composite mass transfer heat exchange plate unit 21 after inflation is 9mm, and the wall thickness of the protruding area is 0.70~0.80mm; the spacing of the external flow channels is 18mm.

[0099] Operating conditions: 2000 Nm 3 A 150-hour full-load continuous operation test was conducted at an operating pressure of 2.5 MPa. During this test, due to the excessively flat plate surface and the extreme lack of turbulence points, effective micro-turbulence between the external gas and liquid phases was difficult to form, resulting in an extremely thick heat and mass transfer boundary layer. The transient temperature control thermal response time of the system was measured to be significantly delayed to over 480 ms, meaning the heat released by the absorption reaction could not be removed in time. This led to an abnormal increase in the local temperature of the absorbent liquid film throughout the tower (exceeding 48°C), ultimately resulting in a sharp deterioration in the H2S emission concentration at the top of the tower to approximately 15 ppm.

[0100] Regarding structural reliability, the disassembly and inspection after shutdown of Examples 1-3 and Comparative Examples 2-3 showed that there was no leakage in the composite mass transfer heat exchange plate unit 21 of each integrated internal component 2, the coating was well adhered, and due to the degree of freedom of thermal expansion provided by the comb-shaped limiting groove 221 on the upper positioning flange 22, the array of composite mass transfer heat exchange plate units 21 in the integrated internal component 2 still maintained strict geometric parallelism after experiencing temperature changes during start-up and shutdown, and no warping or local buckling deformation caused by thermal stress occurred.

[0101] In summary, the above application examples 1-3 and comparative examples 1-3 jointly verify that the composite mass transfer and heat exchange plate unit 21, integrated internal components 2 and isothermal desulfurization tower of the present invention have successfully achieved the coupling of mass transfer enhancement and heat integration on an industrial scale, providing a reliable engineering paradigm for low-energy deep purification of high-sulfur natural gas.

[0102] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A composite mass transfer heat exchange flat plate unit, characterized by, It includes a plate-shaped body, which is a thin-shell structure with an internal cavity, having a first end and a second end opposite to each other in the X direction, a first side and a second side opposite to each other in the Y direction, and a first main surface and a second main surface opposite to each other in the Z direction; the X, Y, and Z directions are perpendicular to each other; The periphery of the plate-shaped body has a peripheral sealing portion that connects the edges of the first main surface and the second main surface to form a closed boundary of the cavity; the cavity is provided with a plurality of supporting connecting portions extending along the Z direction and partially connecting the first main surface and the second main surface. The orthographic projection of the supporting connecting portions on the XY plane is arranged in an array at intervals along both the X and Y directions, and the supporting connecting portions in adjacent rows are staggered in the X direction; the portions of the first main surface and the second main surface, except for the areas where the peripheral sealing portion and the supporting connecting portions are located, all protrude outward in mutually distancing directions, forming a plurality of adjacent and interconnected micro-cavities defined by the supporting connecting portions in the cavity. At the same time, the outer surfaces of the first main surface and the second main surface are respectively formed with undulating contours composed of alternating recessed and protruding regions. In the orthographic projection on the XY plane, the projection of the recessed region overlaps with the projection of the supporting connection, the projection of the protruding region covers the projection of the highest region of the micro-chamber, and the sum of the orthographic projection areas of the supporting connection on the XY plane accounts for 1.4~12.6% of the orthographic projection area of ​​the plate-shaped body on the XY plane; the wall thickness difference of the thin shell structure in the protruding region is not greater than 0.5mm; The first end has a cooling medium inlet communicating with the cavity, and the second end has a cooling medium outlet communicating with the cavity, forming a cooling medium flow channel from the first end to the second end; in use, the outer surfaces of the first main surface and the second main surface are in contact with the external mass transfer fluid to form a heat transfer-mass transfer interface; cooling medium flows in the cooling medium flow channel.

2. The composite mass transfer heat exchange plate unit according to claim 1, characterized in that, The first main surface and the second main surface are mirror-symmetrical with respect to the mid-plane in the Z direction of the plate-shaped body. The portion of the first main surface, except for the area where the peripheral sealing part and the supporting connection part are located, protrudes outward in the +Z direction. The portion of the second main surface, except for the area where the peripheral sealing part and the supporting connection part are located, protrudes outward in the -Z direction. The sum of the orthographic projection areas of the supporting connection part in the XY plane accounts for 4.5 to 5% of the orthographic projection area of ​​the plate-shaped body in the XY plane.

3. The composite mass transfer heat exchange plate unit according to claim 1, characterized in that, The orthographic projection of the support connection part on the XY plane is a staggered diamond array; the center distance between adjacent support connection parts is 10~30mm; the material of the plate-shaped body is 316L stainless steel, 2205 duplex steel or titanium; in the Z direction, the maximum outline height of the plate-shaped body is 3~9mm.

4. The composite mass transfer heat exchange plate unit according to claim 1, characterized in that, The outer surfaces of the first and second main surfaces are both provided with a TiO2-SiO2 superhydrophilic nano-coating, such that the contact angle between the outer surfaces of the first and second main surfaces and water is <5°, and the thickness of the TiO2-SiO2 superhydrophilic nano-coating is 50~500nm.

5. The composite mass transfer heat exchange plate unit according to claim 1, characterized in that, In the orthographic projection of the XY plane, both the cooling medium inlet and the cooling medium outlet are located within the first half-width region of the plate-shaped body and are adjacent to the first side portion; wherein, the first half-width region is the half-region of the plate-shaped body in the Y direction defined by the midline between the first side portion and the second side portion, close to the first side portion.

6. An integrated internal component, characterized in that, It includes a composite mass transfer heat exchange plate unit as described in any one of claims 1 to 5, and a frame for supporting and fixing the composite mass transfer heat exchange plate unit. The plurality of composite mass transfer heat exchange plate units are arranged vertically and parallel to each other, and adjacent composite mass transfer heat exchange plate units form an external flow channel for the gas to be treated and the absorbent to flow. The cross-sectional width of the external flow channel is 1 to 2 times the maximum profile height of the plate-shaped body of the composite mass transfer heat exchange plate unit.

7. The integrated internal component according to claim 6, characterized in that, The undulating profiles of adjacent composite mass transfer heat exchange plate units are continuous wavy curved surfaces extending in the vertical direction, and the protruding and recessed areas of the two are arranged opposite each other; in the horizontal direction, the vertical spacing between adjacent composite mass transfer heat exchange plate units remains constant in the vertical direction, so that the external flow channel has a uniform cross-sectional width in the vertical direction.

8. An isothermal desulfurization tower, characterized in that, Including the tower body and cooling medium circulation system; An isothermal desulfurization chamber is formed inside the tower body. The bottom of the tower body is provided with a sulfur-containing gas inlet that communicates with the isothermal desulfurization chamber, and the top of the tower body is provided with a gas outlet that communicates with the isothermal desulfurization chamber. An absorbent spraying device is provided at the top of the isothermal desulfurization chamber, and a drain outlet that communicates with the outside of the tower body is provided at the bottom. The isothermal desulfurization chamber is provided with several sets of integrated internal components as described in any one of claims 6 to 7 arranged at intervals along the vertical direction. The cooling medium circulation system includes a cooling medium inlet main pipe and a cooling medium outlet main pipe; the cooling medium inlet main pipe is connected to the cooling medium inlet of each composite mass transfer heat exchange plate unit in the integrated internal component through multiple parallel cooling medium inlet branch pipes, and the cooling medium outlet main pipe is connected to the cooling medium outlet of each composite mass transfer heat exchange plate unit in the integrated internal component through multiple parallel cooling medium outlet branch pipes.

9. The isothermal desulfurization tower according to claim 8, characterized in that, Each set of integrated internal components is fixed to the isothermal desulfurization chamber by the frame. The frame includes an upper positioning flange and a lower support flange fixed to the inner wall of the isothermal desulfurization chamber. The upper positioning flange has a comb-shaped limiting groove. The lower support flange includes an annular support part and a bottom support mesh located inside the annular support part. The bottom support mesh is made of grid or wire mesh, and its mesh openings are through to allow liquid to pass through. The top of each composite mass transfer heat exchange plate unit is inserted into the comb-shaped limiting groove, and the bottom rests on the bottom support mesh. There is a margin of movement between the sidewall of the comb-shaped limiting groove and the top edge of the composite mass transfer heat exchange plate unit, so as to limit the displacement of the composite mass transfer heat exchange plate unit in the horizontal direction, and not to hinder the slight movement of the composite mass transfer heat exchange plate unit in the vertical direction. The bottom support net only provides vertical support and does not constrain the longitudinal thermal expansion of the composite mass transfer heat exchange plate unit along its X direction, thus forming a non-rigid connection structure that restricts lateral displacement but allows free axial thermal expansion.

10. A method for gas desulfurization using the isothermal desulfurization tower according to any one of claims 8 to 9, characterized in that, Includes the following steps: S1. Cooling medium distribution: Cooling medium is provided to the integrated internals of the isothermal desulfurization tower, so that the cooling medium flows from bottom to top in the cooling medium flow channel inside the plate-shaped body of the composite mass transfer heat exchange plate unit. S2. Absorbent film formation: The absorbent is sprayed from the top of the isothermal desulfurization chamber through the absorbent spraying device, so that the absorbent flows from top to bottom along the outer side of the plate-shaped body of the composite mass transfer heat exchange plate unit, and forms a turbulent absorbent liquid film under the action of the undulating contour. S3. Countercurrent contact: Sulfur-containing gas is introduced from the bottom of the isothermal desulfurization chamber through the sulfur-containing gas inlet, so that it flows from bottom to top in the external flow channel of the integrated internal component and makes countercurrent contact with the absorbent liquid film to carry out mass transfer reaction; S4. In-situ isothermal control: The cooling medium flowing inside the plate-shaped body of the composite mass transfer heat exchange plate unit is used to dynamically remove the reaction heat of the gas-liquid reaction interface in situ through the wall of the plate-shaped body, thereby controlling the temperature of the absorbent in the isothermal desulfurization chamber to be maintained within the range of 35~45℃. S5. Product discharge: The clean gas after desulfurization is discharged through the gas outlet at the top of the tower, and the rich liquid after reaction is collected at the bottom of the tower and discharged through the liquid outlet.

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