A heat exchanger with double-dimension gradient corrugation synergistic heat exchange and a design method thereof

Abstract

The application discloses a heat exchanger with double-dimension gradually-changing corrugation and cooperative heat exchange and a design method thereof, and belongs to the technical field of high-efficiency heat exchange. The heat exchanger comprises an outer gas collecting cavity section, an inner gas collecting cavity section and a plurality of heat exchange sheets. The outer wall of the heat exchange sheet is provided with a corrugation with a periodically and radially gradually-changing amplitude, and is provided with scale textures. The inner part is provided with a micro channel which oscillates in double projection planes and gradually expands along the flow direction of the medium. The first heat exchange medium is distributed by the inner gas collecting cavity section, flows radially in the micro channel, and exchanges heat with the second heat exchange medium in the flow channel on the outer side of the heat exchange sheet. The heat exchanger adopts a circumferential modular configuration which can be independently disassembled and replaced, or an integrated annular configuration without a unit partition. The application utilizes the cooperation of the external gradually-changing corrugation and the internal oscillating micro channel to strengthen the heat exchange, and can be integrally formed by adopting a laser powder bed melting process, and is suitable for intercoolers, precoolers and regenerators with hydrogen, helium or other fluids as the medium.

Description

Technical Field

[0001] This invention belongs to the field of high-efficiency heat exchanger technology, specifically relating to a heat exchanger with dual-dimensional gradual corrugation synergistic heat exchange and its design method, which is particularly suitable for extreme temperature difference, high pressure and compact installation conditions. Background Technology

[0002] The thrust-to-weight ratio of an aero-engine is a crucial indicator of engine performance. For hydrogen-fueled aero-engines, an intercooler between the low-pressure and high-pressure compressors utilizes the cold source properties of cryogenic hydrogen to cool the high-temperature air discharged from the low-pressure compressor. This process effectively reduces the inlet temperature of the high-pressure compressor, thereby increasing the air density and flow rate entering it. Ultimately, this intercooling cycle significantly improves the engine's thrust-to-weight ratio and overall thermodynamic cycle efficiency. Under the same pressure ratio and similar compression efficiency, the compressor's final compression temperature and compression work per unit volume are typically positively correlated with the inlet absolute temperature. Lowering the inlet air temperature helps reduce subsequent compression work, improves compressor operating margin, and enhances overall efficiency. Simultaneously, hydrogen, after absorbing heat and becoming warmer, is used as preheated fuel before entering the combustion chamber, improving the mixing and combustion organization after hydrogen injection. Since hydrogen intercoolers typically need to be embedded in confined spaces such as intermediate casings, their structure must simultaneously meet requirements for high heat transfer efficiency, low pressure drop, lightweight design, resistance to extreme temperature differences, vibration fatigue resistance, and high reliability.

[0003] From the perspective of compressor power consumption, for an ideal gas and a given pressure ratio π, the unit compression work of a single-stage compressor can be written as w = c_p·T_in·(π^((k-1) / k)-1) / η_c; for a multi-stage compressor with a total pressure ratio Π and n stages, the total unit compression work can be written as w_total = n·c_p·T_in·(Π^((k-1) / (k·n))-1) / η_c. Where w is the compressor unit compression work, c_p is the specific heat capacity at constant pressure, T_in is the inlet absolute temperature, π and Π are the single-stage pressure ratio and total pressure ratio respectively, k is the adiabatic index, η_c is the compressor efficiency, and n is the compressor stage number. Therefore, under the same conditions of pressure ratio, efficiency, and mass flow rate, the power consumption of the high-pressure compressor is approximately proportional to the inlet absolute temperature. Reducing the inlet temperature of the high-pressure compressor using a hydrogen intercooler can reduce the subsequent compression work.

[0004] Traditional intercooling systems for aero engines are typically located after the low-pressure compressor and before the high-pressure compressor, or they can be situated within the annular confined space formed by the intermediate casing, splitter ring, bypass duct, and core engine flow path. The hot-end medium is generally the high-temperature compressed air discharged from the low-pressure compressor, while the cold source medium can be bypass air or fuel. Existing solutions typically achieve heat exchange through plates, fins, flat plates, tube bundles, or annular manifolds, but these often require additional flow-guiding and diffuser channels, manifolds, bypass structures, or liquid-cooled circuits, which can increase flow losses, structural weight, and maintenance complexity.

[0005] For aero-engines that use cryogenic hydrogen as fuel or a cold source, cryogenic hydrogen can be used as fuel and its low temperature and heat absorption capacity can be used to directly cool compressed air. However, hydrogen density decreases and volumetric flow rate increases when heated, and it has high diffusivity and high-pressure sealing requirements. If traditional equal-diameter tube bundles, uniform fins, or ordinary flat plate structures are used, it is easy to cause increased pressure drop on the medium side, local thermal stress concentration, thermal crosstalk between the medium before and after heat exchange, and difficulties in maintenance and inspection.

[0006] In conventional intercoolers, precoolers, and regenerators that use helium as a cold source or circulating working fluid, it is also necessary to balance heat exchange area, medium-side pressure drop, flow distribution, and sealing reliability within a limited volume.

[0007] While existing shell-and-tube, plate-fin, printed circuit board, and corrugated plate heat exchangers are relatively mature, they still suffer from problems such as large size and weight, insufficient heat exchange area utilization, numerous connection interfaces, and difficulties in maintenance and replacement within a compact annular space. In existing technologies, while corrugated plates can increase the heat exchange area, their corrugation parameters are usually fixed; microchannel heat exchangers have high specific surface areas, but their flow channels are mostly straight and of uniform diameter; biomimetic surface structures can improve near-wall flow, but they have not yet achieved synergy with gradually changing corrugations and spatially oscillating microchannels. Limited by traditional machining, brazing, diffusion welding, or assembly processes, it is difficult to simultaneously achieve complex three-dimensional microchannels, gradually changing inner diameters, scaly textured walls, and integrated gas collection chamber structures within a thin-walled heat exchange region. Furthermore, connection interfaces may become weak points under high- and low-temperature cycling and high-pressure media sealing conditions.

[0008] In summary, current technologies lack a heat exchanger that can simultaneously meet the requirements of high heat transfer efficiency, low pressure drop, lightweight design, resistance to extreme temperature differences, and high reliability, and is suitable for compact annular spaces such as the intermediate casing of aero-engines. Specifically, the corrugated parameters of existing corrugated plate heat exchangers are mostly fixed values, making it impossible to optimize them based on radial flow velocity distribution and temperature gradient; the flow channels of existing microchannel heat exchangers are mostly straight and of equal diameter, making it difficult to accommodate the volume expansion of the first heat exchange medium after heating; existing biomimetic surface structures have not yet achieved synergy with gradient corrugations and spatial oscillating microchannels; and traditional manufacturing processes struggle to achieve the integrated design of the gas collection cavity, thin-walled heat exchange plates, three-dimensional microchannels, and surface textures. Therefore, there is an urgent need in this field for a heat exchanger and its design method that can achieve efficient heat transfer through multi-dimensional synergy of the structure itself. Summary of the Invention

[0009] The purpose of this invention is to address the technical problems existing in the prior art, such as the difficulty in balancing heat exchange efficiency and flow resistance, the inability of fixed corrugation parameters to match radial temperature distribution, the inability of microchannels to adapt to changes in medium volume along the flow path, the difficulty of maintenance in compact annular spaces, and the difficulty of integral molding of complex three-dimensional structures. This invention provides a heat exchanger with dual-dimensional gradient corrugated synergistic heat exchange and its design method. By setting a radially gradient corrugated structure and superimposing scaly textures on the outer wall of the heat exchange plate, and setting microchannels that oscillate spatially within two projection planes and whose inner diameter gradually expands along the flow direction inside the heat exchange plate, external flow field disturbances and internal flow field enhancements form synergistic heat exchange through the heat exchange plate wall. Simultaneously, a modular and replaceable configuration or an integrated annular configuration is adopted to adapt to different compact annular installation scenarios, and integral molding is achieved through laser powder bed fusion additive manufacturing, thereby significantly improving heat exchange efficiency while effectively controlling flow resistance.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a heat exchanger with dual-dimensional gradient corrugated synergistic heat exchange, comprising multiple heat exchange regions arranged circumferentially, wherein the multiple heat exchange regions are formed in a unit configuration that is independent and replaceable or in a continuous annular configuration that is integrated with each other; each heat exchange region includes an outer gas collection cavity section, an inner gas collection cavity section, and multiple heat exchange plates disposed between the outer gas collection cavity section and the inner gas collection cavity section; wherein the Z direction is the radial direction of the heat exchange region, the Y direction is the axial direction of the heat exchange plates, and the X direction is the thickness direction of the heat exchange plates; The outer gas collection chamber section includes a first medium inlet chamber and a first medium outlet chamber that are isolated from each other. The first medium inlet chamber is connected to the inner gas collection chamber section via a first medium delivery channel. The inner gas collection chamber section is connected to the inlet of the heat exchange medium microchannel network inside each heat exchange plate. The outlet of the heat exchange medium microchannel network is connected to the first medium outlet chamber section, so that the first heat exchange medium enters from the first medium inlet chamber, is distributed by the inner gas collection chamber section, flows radially outward along the heat exchange medium microchannel network in the Z direction, and converges to the first medium outlet chamber section. An outer flow channel is formed between adjacent heat exchange plates for the second heat exchange medium to flow axially or near-axially in the Y direction. The two heat exchange media exchange heat through the heat exchange plate walls.

[0011] The outer wall of the heat exchange plate forms a radially gradient corrugated structure and is provided with a scale texture. The corrugation period and corrugation amplitude of the radially gradient corrugated structure gradually change radially along the heat exchange area. The heat exchange medium microchannel network includes multiple oscillating gradually expanding inner diameter microchannels. The center line of the oscillating gradually expanding inner diameter microchannels has the Z direction as the main radial direction. It forms an in-plane waveform in a first projection plane including the Z and Y directions and forms spatial oscillation in a second projection plane including the Z and X directions. The inner diameter of the oscillating gradually expanding inner diameter microchannels gradually increases along the flow direction of the first heat exchange medium.

[0012] In one embodiment, the plurality of heat exchange zones are multiple independent heat exchange units equally distributed circumferentially. Any independent heat exchange unit can be removed and replaced while maintaining the installation state of the other independent heat exchange units. Each independent heat exchange unit has an outer cavity unit partition on both sides, and the first medium conveying channel is located inside the outer cavity unit partition. When the heat exchanger is used as an intercooler in an aero-engine intermediate casing, the plurality of independent heat exchange units are respectively arranged within sectors defined by adjacent radial load-bearing plates. Each independent heat exchange unit is correspondingly provided with at least one first medium inlet branch pipe and at least one first medium outlet branch pipe. The heat exchange plates, the outer cavity unit partitions, and the radial load-bearing plates are all arranged radially or nearly radially. When an independent heat exchange unit experiences performance degradation, abnormal leakage, or damage, that independent heat exchange unit can be removed and replaced with a spare unit.

[0013] In one embodiment, the multiple heat exchange zones are integrated and connected to form an integral annular structure without external cavity unit partitions. Multiple heat exchange plates are continuously arranged circumferentially and are circumferentially curved to form a circumferentially continuous curved heat exchange plate array. The first medium delivery channel is disposed inside the heat exchange plates and connects the first medium inlet cavity to the inner gas collection cavity section. The integrated configuration improves the circumferential space utilization in scenarios without support plate partition constraints by eliminating unit partitions and continuously arranging heat exchange plates.

[0014] Furthermore, for the integrated configuration, the heat exchanger fins adopt a curved structure, that is, the original heat exchanger fins are bent in the ZX plane, and the bending arc is a parabolic structure. The governing equation is: Z = H - 4H / L 2 (L·tL / 2) 2 Where H is the projected height from the endpoint of the parabola along the X-axis to the center vertex. The length of the heat exchange plate before bending should be L_1 = 0.5 (L... 2 +16H 2 ) 0.5 +L 2 / 8H·ln((4H+(L 2 +16H 2 )) / L), to achieve a heat exchange plate length of L along the Z direction after bending; Besides the parabolic bending method of the heat exchanger plates mentioned above, other bending schemes can also be adopted. The original heat exchanger plates still bend within the ZX plane, but the governing equations are: , Where M is the projected distance between the first and last endpoints of the curve in the X-axis direction, N is the number of horizontal transition points (i.e., the curve slope changes symmetrically relative to the transition point after passing through the transition point), p is the turning radius control parameter after passing through the horizontal transition point, and q is the overall lateral curvature of the curve. The length of the heat exchange plate before bending should be... To achieve a projected length of L along the Z direction of the heat exchange plate after bending.

[0015] After the control equations are established for each heat exchanger, the origin of space is used as the center to form a circumferential array to form a modular structural unit with intermediate partitions or an integrated structure without intermediate partitions.

[0016] Furthermore, the corrugation period T_a(r) and corrugation amplitude A_a(r) of the radially tapered corrugated structure satisfy the following governing equations: taking the effective total length of the heat exchange plate in the radial direction of the heat exchange region as L, establishing radial coordinates r along the Z direction, 0≤r≤L, T_a(0)=T1, A_a(0)=A1, T_a(L)=T2, A_a(L)=A2; taking the normalized variable t∈[0,1], the profile of the radially tapered corrugated structure (31) is determined by the following parametric equations: Z_a(t) = L·t, X_a(t)=[A1+(A2-A1)t]·sin(2π·N·t·k), Y_a(t)=0, Where Z_a(t) is the principal coordinate along the radial direction of the heat exchange region, X_a(t) is the corrugation offset along the thickness direction of the heat exchange plate, Y_a(t) is the corrugation offset along the axial direction of the heat exchange plate, N is the number of periods within the length L, and k is the exponent of the radial wavelength variation. This structure is used to match radial velocity distribution, temperature gradient, and local heat exchange requirements.

[0017] Furthermore, the centerline of the oscillating, gradually expanding inner diameter microchannel is described by the spatial parameter curve C(t)=(X_h(t),Y_h(t),Z_h(t)); the normalized variable t∈[0,1] is taken as follows: Z_h(t) = L_h·t, X_h(t)=[B1+(B2-B1)t]·sin(2π·N_h·t·k), Y_h(t)=B_y·sin(2π·N_h·t·k+φ), Where L_h is the effective length of the microchannel in the radial direction, Z_h(t) represents the advancing position of the main radial direction along the Z direction, Y_h(t) represents the in-plane waveform amplitude of the centerline along the heat exchanger axis in the YZ plane, X_h(t) represents the spatial oscillation amplitude of the centerline along the thickness direction of the heat exchanger in the XZ plane, B1 and B2 are the waveform amplitude parameters of the heat exchanger in the X direction, By is the oscillation amplitude parameter of the heat exchanger in the Y direction, N_h is the number of periods within the effective length of the microchannel in the radial direction, φ is the phase difference between the waveform displacement in the Y direction and the oscillation displacement in the X direction, and k is the exponent of the wavelength variation along the radial direction.

[0018] Furthermore, the phase difference φ is 90 degrees, so that the oscillating gradually expanding inner diameter microchannel forms a three-dimensional spiral or quasi-spiral oscillating flow channel inside the heat exchange plate; each oscillating gradually expanding inner diameter microchannel in the same heat exchange plate is arranged in a linear array along the axial direction, and the solid wall thickness in the X direction at any position is not less than 0.5 mm; the inner diameter d_h(s) of the oscillating gradually expanding inner diameter microchannel gradually increases from the inlet inner diameter d_in to the outlet inner diameter d_out along the arc length s of the flow path, and d_out>d_in, in order to adapt to the problem of increased pressure loss caused by the volume expansion of the medium due to heating.

[0019] Furthermore, the scale texture includes at least one of continuous or discretely arranged arc-shaped micro-protrusions, overlapping scale-like ridges, or biomimetic scale units; a heat insulation cavity is provided between the first medium inlet cavity and the first medium outlet cavity, the heat insulation cavity being a hollow structure or having a low thermal conductivity cell structure; the low thermal conductivity cell structure is selected from one or more combinations of BCC lattice, Kelvin cell, and Gyroid surface cell, and the equivalent thermal conductivity is controlled by adjusting the rod diameter, cell size, volume fraction, etc., to block thermal crosstalk between different first heat exchange media, improve the effective heat exchange capacity, and at the same time alleviate the thermal strain induced by structural temperature difference, inhibit thermal cracking, and ensure structural safety.

[0020] Furthermore, each independent heat exchange unit in the mutually independent and replaceable unit configuration or the continuous annular configuration is an integrated continuous structure oriented towards laser powder bed fusion additive manufacturing. The outer gas collecting cavity section, the inner gas collecting cavity section, the heat exchange plate, the heat exchange medium microchannel network, the first medium conveying channel, and the outer cavity unit partition provided in the unit configuration are integrally formed by laser powder bed fusion. The outer gas collecting cavity section, the inner gas collecting cavity section, and the heat exchange plate adopt a rounded corner transition or variable thickness transition structure, and a connecting path for powder discharge after forming is provided between the heat exchange medium microchannel network, the first medium conveying channel, and the external branch pipe.

[0021] Secondly, the present invention provides a design method for a heat exchanger with dual-dimensional gradient corrugated synergistic heat exchange, comprising the following steps: S1. Based on the installation envelope, support and sealing boundaries, heat exchange conditions and heat exchange medium, determine the independent and replaceable unit configuration or the continuous ring configuration that is integrated with each other. Determine the number of heat exchange areas, circumferential arrangement, outer gas collection cavity section, inner gas collection cavity section, heat exchange plates and the initial dimensions of the first medium conveying channel, and establish the heat exchange flow path between the first heat exchange medium and the second heat exchange medium. S2, determine the radial gradient corrugation parameters, scale texture parameters, and spatial oscillation parameters and gradually expanding inner diameter parameters of the oscillating gradually expanding inner diameter microchannel of the heat exchange plate, and generate a parametric three-dimensional model that meets the installation and manufacturing constraints. S3 sets heat transfer performance, flow resistance, temperature uniformity, flow distribution uniformity, and structural quality as optimization objectives. It obtains performance data through simulation and / or experiments and performs multi-objective optimization to verify candidate structures and output heat exchanger structural parameters that meet the constraints.

[0022] Further, step S3 includes: Sample points were generated in a design variable space consisting of configuration parameters, ripple period and amplitude, scale texture scale, microchannel spatial oscillation parameters, and gradually expanding inner diameter parameters using experimental design methods. Through computational fluid dynamics simulation, thermal-structure coupling simulation and / or experimental testing, the heat transfer, outlet temperature, pressure drop on the first heat transfer medium side, pressure drop on the second heat transfer medium side, wall temperature uniformity, flow distribution uniformity and structural mass of each sample point are obtained. Establish the mapping relationship between design variables and performance data in the design variable space, and perform multi-objective optimization under the conditions of satisfying the installation envelope, minimum wall thickness, minimum channel spacing, sealing boundary and laser powder bed melting forming constraints to obtain the Pareto candidate solution set; Candidate structures are selected from the Pareto candidate solution set and verified by high-fidelity simulation and / or experiment. When the verification result does not meet the preset index, return to step S2 to update the parameter range and repeat step S3.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects: First, this invention employs radially tapered corrugations and spatially oscillating microchannels with gradually expanding inner diameters to synergistically enhance heat exchange on both the first and second heat exchange medium sides. The radially tapered corrugations increase the effective heat exchange area and create continuous turbulence on the air side, while the spatially oscillating microchannels generate strong secondary flow on the first heat exchange medium side. The two components form thermal coupling through the heat exchange plate walls. Simultaneously, the tapered corrugations guide the flow, and the gradually expanding inner diameter microchannels help control flow resistance. The radially tapered corrugations allow for customized turbulence intensity based on radial velocity distribution and temperature gradients, while the expanding inner diameter accommodates the volume expansion of the first heat exchange medium after heating, effectively suppressing pressure drop surges.

[0024] Second, the heat exchanger surface of the present invention is provided with a scaly texture to enhance heat transfer. The scaly texture further disrupts the near-wall boundary layer on the air side, achieving significant heat transfer enhancement at the cost of minimal flow resistance.

[0025] Third, the modular configuration of this invention facilitates independent maintenance and replacement, while the integrated configuration facilitates improved utilization of the continuous annular space. In the modular configuration, each independent heat exchange unit can undergo heat treatment, surface treatment, non-destructive testing, airtightness testing, and pressure testing separately; when a unit is blocked, leaking, or damaged, it can be replaced independently along the unit replacement boundary.

[0026] Fourth, the integrated design of this invention for laser powder bed melting (L-PBF) can continuously form gas collection chambers, thin-walled heat exchange plates, wall textures and three-dimensional microchannels, reducing welding or brazing joint interfaces and eliminating weak points at the joint interfaces under high and low temperature cycles and high pressure medium sealing conditions.

[0027] Fifth, the parameterization and multi-objective optimization method of this invention can coordinate multiple performance indicators for different media and operating conditions, and realize closed-loop design from operating condition input, configuration selection, parameterization modeling, performance solution, multi-objective optimization to verification output. Attached Figure Description

[0028] Figure 1 This is a perspective view of a modular heat exchanger unit in an embodiment of the present invention; Figure 2 This is a perspective view of the modular heat exchanger as described in an embodiment of the present invention. Figure 3 This is a cross-sectional view of the modular heat exchanger unit in the XZ direction in an embodiment of the present invention; Figure 4 This is a cross-sectional view of the modular heat exchanger unit in the YZ direction in an embodiment of the present invention; Figure 5 This is a view showing the arrangement of modular unit heat exchange plates in the heat exchanger unit of this invention embodiment; Figure 6 This is a view showing the arrangement of heat exchange plates in the integrated curved heat exchange plate unit in an embodiment of the present invention; Figure 7 This is a perspective view of the curved heat exchanger array unit of the integrated heat exchanger in an embodiment of the present invention; Figure 8 This is a perspective view of the integrated heat exchanger in an embodiment of the present invention; Figure 9 This is a temperature field simulation cloud diagram of an embodiment of the hydrogen intercooler of the present invention; Figure 10 This is a simulation cloud diagram of the pressure field of an embodiment of the hydrogen intercooler of the present invention; Figure 11 This is a flowchart illustrating the multi-objective optimization design of the heat exchanger in an embodiment of the present invention.

[0029] Explanation of reference numerals in the attached drawings: 1-Outer gas collection chamber section, 11-First medium inlet chamber, 12-First medium outlet chamber, 13-Insulation chamber, 14-First medium inlet branch pipe, 15-First medium outlet branch pipe, 16-Outer chamber unit partition, 17-Pressure stabilizing chamber, 2-Inner gas collection chamber section, 21-First medium conveying channel, 22-Uniform orifice plate, 23-Orifice plate distribution hole, 3-Heat exchange plate, 31-Radial gradient corrugated structure, 32-Oscillating gradually expanding inner diameter microchannel, 33-Outer flow channel, 34-Microchannel inlet, 35-Microchannel outlet, 36-Scale texture, 5-Intermediate casing. Detailed Implementation

[0030] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0031] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] In this invention, the first heat exchange medium refers to the medium flowing in the heat exchange medium microchannels inside the heat exchange plate, which can be a gaseous or liquid medium; the second heat exchange medium refers to the medium flowing in the flow channels outside the heat exchange plate. Example 1 uses cryogenic hydrogen as the first heat exchange medium, and Example 2 uses helium as the first heat exchange medium; these are only used to illustrate different applications and do not constitute a limitation on the type of medium. The first heat exchange medium can be selected from hydrogen, helium, nitrogen, air, fuel, lubricating oil, refrigerant, coolant, or other flowable heat exchange media depending on the application scenario; the second heat exchange medium can be air, fuel gas, or other fluid to be heat exchanged. Changing the type of medium does not change the core structural features such as radially gradient corrugations, scale texture, spatially oscillating gradually expanding inner diameter microchannels, and modular or integrated configuration.

[0033] Example 1: Modular heat exchanger like Figures 1 to 5 As shown, this embodiment provides a heat exchanger with dual-dimensional gradient corrugated synergistic heat exchange. This heat exchanger is a modular heat exchanger, including multiple heat exchange regions arranged circumferentially. The multiple heat exchange regions form a modular heat exchanger with an independent and replaceable unit configuration. Specifically, the heat exchanger is composed of eight independent heat exchange units arranged circumferentially to form an annular heat exchange region. Each independent heat exchange unit corresponds to an approximately 45-degree sector and is located within the sector defined by adjacent radial load-bearing plates of the intermediate casing 5. Each independent heat exchange unit includes an outer gas collection cavity section 1 on the outer side, an inner gas collection cavity section 2 on the inner side, and multiple heat exchange plates 3 arranged between the two. The Z direction is defined as the radial direction of the heat exchange region, the Y direction as the axial direction of the heat exchange plates, and the X direction as the thickness direction of the heat exchange plates.

[0034] Each independent heat exchange unit is equipped with an outer cavity unit partition 16 on both sides. The radial load-bearing support plates of the heat exchange plates 3, the outer cavity unit partition 16, and the intermediate casing 5 are arranged radially or nearly radially, and the heat exchange plates as a whole are not circumferentially bent. The outer gas collection cavity section 1 includes a low-temperature hydrogen gas cavity serving as the first medium inlet cavity 11 and a heat-exchange hydrogen gas cavity serving as the first medium outlet cavity 12. A heat insulation cavity 13 is provided between the two. The heat insulation cavity 13 can be a hollow structure or it can be equipped with a low thermal conductivity cell structure. The low thermal conductivity cell structure is selected from one or more combinations of BCC lattice, Kelvin cell, and Gyroid curved surface cell, which is used to reduce thermal crosstalk between the first heat exchange medium before and after heat exchange and improve the effective heat exchange capacity. Each independent heat exchange unit is equipped with two first medium inlet branch pipes 14 and one first medium outlet branch pipe 15; the number of branch pipes can be adjusted according to the flow distribution requirements.

[0035] The first heat exchange medium enters the first medium inlet chamber 11 through the first medium inlet branch pipe 14, flows through the first medium delivery channel 21 located inside the outer cavity unit partition 16 to the inner gas collection chamber section 2, achieves uniform and stable pressure distribution in the pressure stabilizing chamber 17, and then enters the heat exchange medium microchannel network inside each heat exchange plate 3 through the perforated plate distribution holes 23 on the uniform perforated plate 22. It enters the oscillating gradually expanding inner diameter microchannel 32 from the microchannel inlet 34, and then flows out from the microchannel outlet 35. That is, the first medium inlet chamber 11 is connected to the inner gas collection chamber section 2 through the first medium delivery channel 21, and the inner gas collection chamber section 2 is connected to the inlet (i.e., microchannel inlet 34) of the heat exchange medium microchannel network inside each heat exchange plate 3. The first heat exchange medium flows radially outward along the Z direction and converges to the first medium outlet chamber 12 (i.e., the outlet of the heat exchange medium microchannel network is connected to the first medium outlet chamber 12), and finally is discharged through the first medium outlet branch pipe 15. An outer flow channel 33 is formed between adjacent heat exchange plates 3 for the flow of the second heat exchange medium. The second heat exchange medium passes through the outer flow channel 33 axially or near axially in the Y direction and exchanges heat with the first heat exchange medium through cross flow.

[0036] The heat exchange medium microchannel network includes multiple oscillating gradually expanding inner diameter microchannels 32. The centerline of the oscillating gradually expanding inner diameter microchannel 32 has the Z direction as the main radial direction, and forms an in-plane waveform in the first projection plane including the Z and Y directions and forms spatial oscillation in the second projection plane including the Z and X directions. The inner diameter of the oscillating gradually expanding inner diameter microchannel 32 gradually increases along the flow direction of the first heat exchange medium.

[0037] In this embodiment, the first heat exchange medium is cryogenic hydrogen, and the second heat exchange medium is compressed air. Therefore, the heat exchanger in this embodiment constitutes a hydrogen intercooler or a hydrogen precooler.

[0038] The outer wall surface of the heat exchanger 3 is provided with a radially gradient corrugated structure 31 and superimposed with a scale texture 36. The corrugation period and corrugation amplitude of the radially gradient corrugated structure 31 gradually change radially along the heat exchange region. Specifically, let the total effective radial length of the heat exchanger 3 along the Z direction be L, and establish a radial coordinate r along the Z direction, 0≤r≤L; the corrugation period T_a(r) and corrugation amplitude A_a(r) gradually change from the initial period T1 and initial amplitude A1 to the final period T2 and final amplitude A2, that is, T_a(0)=T1, A_a(0)=A1, T_a(L)=T2, A_a(L)=A2, to match the radial velocity distribution, temperature gradient and local heat exchange requirements. The scale texture 36 adopts at least one of the following: continuous or discretely arranged arc-shaped micro-protrusions, overlapping scale-like ridges or biomimetic scale units, to diffuse local heat flow on the wall and disturb the near-wall boundary layer of air.

[0039] As a radially gradient corrugated control function, with the normalized variable t∈[0,1], the profile of the radially gradient corrugated structure 31 is determined by the following parametric equations: Z_a(t) = L·t, X_a(t)=[A1+(A2-A1)t]·sin(2π·N·t·k), Y_a(t) = 0; Where Z_a(t) is the principal coordinate along the radial direction of the heat exchange region, X_a(t) is the corrugation offset along the thickness direction of the heat exchange plate, Y_a(t) is the corrugation offset along the axial direction of the heat exchange plate, N is the number of periods within the length L, and k is the exponent of the radial wavelength variation. T1, A1, T2, A2, N, and k can all be used as design variables for subsequent multi-objective optimization.

[0040] The spatial parameter curve C(t)=(X_h(t),Y_h(t),Z_h(t)) of the centerline of the oscillating, gradually expanding inner diameter microchannel 32 is used to describe the process, with the normalized variable t∈[0,1]: Z_h(t) = L_h·t, X_h(t)=[B1+(B2-B1)t]·sin(2π·N_h·t·k), Y_h(t)=B_y·sin(2π·N_h·t·k+φ); Where L_h is the effective length of the microchannel in the radial direction, Z_h(t) represents the advancing position of the main radial direction along the Z direction, Y_h(t) represents the in-plane waveform amplitude of the center line along the heat exchanger axial direction in the YZ plane, X_h(t) represents the spatial oscillation amplitude of the center line along the thickness direction of the heat exchanger in the XZ plane, B1 and B2 are the waveform amplitude parameters of heat exchanger 3 in the X direction, B_y is the oscillation amplitude parameter of heat exchanger 3 in the Y direction, N_h is the number of periods within the effective length of the microchannel in the radial direction, φ is the phase difference between the waveform displacement in the Y direction and the oscillation displacement in the X direction, and k is the exponent of the wavelength variation along the radial direction.

[0041] When φ is 90 degrees, the oscillating gradually expanding inner diameter microchannel 32 forms a three-dimensional spiral or quasi-spiral oscillation path inside the heat exchange plate 3. Each oscillating gradually expanding inner diameter microchannel 32 within the same heat exchange plate 3 is arranged in a linear array along the axial direction, ensuring a solid wall thickness of not less than 0.5 mm in the X direction at any position. The inner diameter d_h(s) of the oscillating gradually expanding inner diameter microchannel 32 gradually and uniformly increases along the flow path arc length s from the inlet inner diameter d_in to the outlet inner diameter d_out, and d_out > d_in.

[0042] During operation, the low-temperature hydrogen gas in the oscillating, gradually expanding inner diameter microchannel 32 absorbs the heat transferred from the compressed air through the heat exchanger plate wall. The radially tapered corrugated structure 31 on the air side increases the effective heat exchange area and forms continuous turbulence, while the scale texture 36 further disrupts the near-wall boundary layer. The spatial oscillating microchannel enhances the disturbance on the first heat exchange medium side, and the gradually expanding inner diameter is used to control the flow rate and pressure drop of the medium after heating. The cooled air flows to the high-pressure compressor, and the heat-absorbing hydrogen gas is sent as preheated fuel to the subsequent hydrogen supply system or combustion chamber.

[0043] Figure 9 and Figure 10 Simulation results of temperature and pressure fields under the same operating conditions are presented to evaluate the uniformity of air outlet temperature, hydrogen outlet temperature, air side pressure drop, and wall temperature. In the two figures, (a1), (b1), and (c1) show the simulation results of the wall surfaces of three types of heat exchangers: straight plate, corrugated plate, and curved corrugated plate, respectively; (a2), (b2), and (c2) show the simulation results of the internal channels of the three types of heat exchangers: straight plate, corrugated plate, and curved corrugated plate, respectively. In an example of actual aero-engine operating conditions, the air inlet temperature is approximately 446 K, and the mass flow rate is approximately 100 kg / s; the hydrogen inlet temperature is approximately 40 K, the pressure is approximately 0.405 MPa, and the mass flow rate is approximately 1.2 kg / s. In a comparative sub-model using three heat exchangers and a periodic boundary, the air mass flow rate is 2.5 kg / s, and the hydrogen mass flow rate is approximately 0.03 kg / s. Table 1 shows the data used to compare the differences in air temperature drop, hydrogen temperature rise, and air pressure drop between the corrugated plate and straight plate heat exchangers under the same operating conditions. Table 1 Comparison of heat transfer performance of hydrogen heat exchanger plates

[0044] As shown in Table 1, compared to the straight plate structure, the air temperature drop using the corrugated plate structure described in this embodiment of the invention is increased by approximately 72.57% (from 11.63K to 20.07K), the hydrogen temperature rise is increased by approximately 103.8% (from 51.8K to 105.58K), while the air-side pressure drop only increases by 12.3%. This indicates that the corrugated plate structure described in this embodiment of the invention can significantly enhance heat transfer at the cost of relatively low flow resistance, exhibiting excellent overall flow and heat transfer performance.

[0045] In this embodiment, the outer gas collecting cavity section 1, inner gas collecting cavity section 2, heat exchange plate 3, heat exchange medium microchannel network, first medium conveying channel 21, uniform perforated plate 22, heat insulation cavity 13, outer cavity unit partition 16, and scale texture 36 are preferably integrally formed by laser powder bed melting (L-PBF). Each independent heat exchange unit in the resulting independent and replaceable unit configuration is an integrated continuous structure oriented towards laser powder bed melting additive manufacturing. Preferably, a rounded corner transition or variable thickness transition structure is provided at the connection points between the outer gas collecting cavity section 1, inner gas collecting cavity section 2, and heat exchange plate 3 to avoid stress concentration and printing defects in sharp corner areas during laser powder bed melting, thereby improving forming quality and structural strength. Simultaneously, a powder discharge path is provided between the heat exchange medium microchannel network, the first medium conveying channel 21, and the external branch pipe. This powder discharge path is used to discharge any remaining unmelted metal powder inside the channels after additive manufacturing, ensuring unobstructed flow in each channel. Each internal flow channel is connected to the external branch pipe via a powder discharge path, and the overhang angle, minimum wall thickness, local radius of curvature, and post-processing accessibility are controlled. Independent heat exchange units undergo heat treatment, surface treatment, non-destructive testing, airtightness testing, and pressure testing respectively; when a heat exchange unit is blocked, leaking, or damaged, it can be replaced independently along the unit replacement boundary.

[0046] Example 2: Integrated Heat Exchanger like Figures 6 to 8 As shown, this embodiment provides another heat exchanger with dual-dimensional gradient corrugated synergistic heat exchange, which includes multiple heat exchange regions arranged circumferentially. These multiple heat exchange regions form an integrated heat exchanger with a continuous annular configuration that is interconnected, making it an integrated annular heat exchanger that is not constrained by the radial load-bearing support plate partitioning of the intermediate casing. During manufacturing, the multiple heat exchange regions are interconnected as a continuous annular structure, without external cavity unit partitions 16 and unit replacement boundaries, forming an overall annular structure. Each heat exchange region includes an outer gas collection cavity section 1, an inner gas collection cavity section 2, and multiple heat exchange plates 3 disposed between them. The outer gas collection cavity section 1, the inner gas collection cavity section 2, and the multiple heat exchange plates 3 are continuously formed circumferentially. This integrated configuration is suitable for scenarios requiring improved circumferential space utilization and reduced unit connections, compression, and sealing interfaces.

[0047] Multiple heat exchange plates 3 are continuously arranged circumferentially and are circumferentially curved to form a curved heat exchange plate array; the outer flow channels 33 between adjacent heat exchange plates 3 extend as the heat exchange plates bend. A first medium conveying channel 21 is located inside the heat exchange plate 3, connecting the first medium inlet cavity 11 with the inner gas collecting cavity section 2; the first heat exchange medium flows from the inner gas collecting cavity section 2 into the pressure stabilizing cavity 17, where the pressure distribution is uniform and stable, and then enters the heat exchange medium microchannel network inside each heat exchange plate 3 through the perforated plate distribution holes 23 on the uniform perforated plate 22. That is, the first medium inlet cavity 11 is connected to the inner gas collecting cavity section 2 via the first medium conveying channel 21, and the inner gas collecting cavity section 2 is connected to the inlet of the heat exchange medium microchannel network inside each heat exchange plate 3. The first heat exchange medium flows radially outward along the Z direction to the first medium outlet cavity 12.

[0048] In this embodiment, helium is used as the first heat exchange medium, and the air to be cooled or other high-temperature gas is used as the second heat exchange medium. Therefore, the heat exchanger in this embodiment constitutes a helium-cooled intercooler, precooler, or regenerator. Helium enters the first medium inlet chamber 11 through the first medium inlet branch pipe 14, passes through the first medium transport channel 21, the inner gas collecting chamber section 2, and the heat exchange medium microchannel network, and then enters the first medium outlet chamber 12. When this integrated heat exchanger is used in a conventional helium-cooled intercooler, precooler, or regenerator, the gas collecting chamber size, number of channels, and gradually expanding inner diameter can be re-determined based on the helium's inlet temperature, pressure, physical properties, and allowable pressure drop. The first heat exchange medium can also be replaced with hydrogen or other gaseous or liquid media.

[0049] The heat exchanger fin 3 in the integrated configuration also features a radially gradient corrugated structure 31 and a scale texture 36. The multiple oscillating, gradually expanding inner diameter microchannels 32 in the heat exchange medium microchannel network also employ spatial oscillation paths within two projection planes and gradually expanding inner diameters along the flow direction. The corrugation control function, microchannel spatial parameter curves, and the definitions of T1, A1, T2, A2, B1, B2, By, N, Nh, k, φ, d_in, and d_out are the same as in Example 1, and their specific values ​​are determined based on the physical properties, flow rate, and heat exchange target of helium and the second heat exchange medium.

[0050] For the integrated structure, heat exchanger 3 adopts a curved structure, that is, it is bent in the ZX plane based on the original heat exchanger, and the bending arc is a parabolic structure. The governing equation is: Z = H - 4H / L 2 (L·tL / 2) 2 Where H is the projected height from the endpoint of the parabola along the X-axis to the center vertex. The length of the heat exchange plate before bending should be L_1 = 0.5 (L 2 +16H 2 ) 0.5 +L 2 / 8H·ln((4H+(L 2 +16H 2 )) / L), to achieve a heat exchange plate length of L along the Z direction after bending.

[0051] Besides the parabolic bending method of heat exchanger plate 3 mentioned above, other bending schemes can also be adopted. The original heat exchanger plate still bends within the ZX plane, but the governing equation is:

[0052]

[0053] Where M is the projected distance between the first and last endpoints of the curve in the X-axis direction, N is the number of horizontal transition points, i.e., the slope of the curve changes symmetrically relative to the transition point after passing through the transition point, p is the turning radius control parameter after passing through the horizontal transition point, and q is the overall lateral curvature of the curve. The length of the heat exchange plate before bending should be... To achieve a projected length of L along the Z direction of the heat exchange plate after bending.

[0054] During operation, the second heat exchange medium flows along the curved outer flow channel 33, and the radially tapered corrugated structure 31 and the scale texture 36 together alter the near-wall flow; helium flows radially within the spatially oscillating, gradually expanding inner diameter microchannel 32. The circumferential curvature extends the outer flow path to increase the heat exchange area, the spatial oscillation enhances internal flow disturbance, and the gradually expanding inner diameter coordinates the state changes and pressure drop of the first heat exchange medium along the flow path. The media on both sides can flow in counter-current or cross-flow configurations depending on the system requirements.

[0055] In this embodiment, laser powder bed melting (L-PBF) is preferably used to integrally form the outer gas collecting cavity section 1, the inner gas collecting cavity section 2, the curved heat exchanger array, the heat exchange medium microchannel network, and the scale texture 36. The resulting continuous annular configuration is an integrated continuous structure for laser powder bed melting additive manufacturing. Alternatively, the continuous annular structure can be divided into several manufacturing segments and then sealed and connected according to the size and material conditions. Preferably, a rounded corner transition or variable thickness transition structure is provided at the connection between the outer gas collecting cavity section 1, the inner gas collecting cavity section 2, and the heat exchanger 3 to avoid stress concentration and printing defects in the sharp corner areas during laser powder bed melting, thereby improving the forming quality and structural strength. At the same time, a powder discharge path is provided between the heat exchange medium microchannel network, the first medium delivery channel 21, and the external branch pipe. This powder discharge path is used to discharge the unmelted metal powder remaining inside the channel after additive manufacturing, ensuring that each flow channel is unobstructed. This integrated configuration can be used in helium or hydrogen intercoolers, precoolers, regenerators, fuel cell thermal management heat exchangers, and compact heat exchange devices in petrochemical, energy, marine, vehicle, electronic cooling, and cryogenic engineering.

[0056] Example 3: Multi-objective optimization design method This embodiment provides a design method for a heat exchanger with dual-dimensional gradient corrugated synergistic heat exchange, used for multi-objective optimization design of the modular or integrated heat exchangers of Embodiments 1 and 2. Figure 11 As shown, the method includes the following steps: S1, Configuration and Flow Path Definition: Input the installation envelope, support and sealing boundaries, inlet status of the first heat exchange medium and the second heat exchange medium, mass flow rate, allowable pressure drop and heat exchange target; determine whether there are branch plate partitions or independent maintenance requirements, and select a modular configuration or an integrated ring configuration accordingly; based on the installation envelope, support and sealing boundaries, heat exchange conditions and heat exchange medium, determine the number of heat exchange areas, circumferential arrangement (such as sector angle), gas collection cavity location (such as outer gas collection cavity section 1, inner gas collection cavity section 2), number of branch pipes, initial size of heat exchange plates, and establish the heat exchange flow path between the first heat exchange medium and the second heat exchange medium.

[0057] Specifically, if there are requirements for partitioning or independent maintenance of the support plate, a modular configuration is selected, and the number of units, sector angle, separable boundary, and conveying channels within the partition plate or heat exchanger are determined. If there are no requirements for partitioning or independent maintenance of the support plate, an integrated configuration is selected, and the continuous ring structure, unidirectional torsion structure, and conveying channels within the heat exchanger are determined.

[0058] S2, Core Structure Parameterization: Configuration identifier, number of heat exchange regions, sector angle, number of heat exchange fins, and circumferential curvature are used as configuration parameters; L, T1, A1, T2, A2, N, k, and scale texture scale S_a are used as outer structure parameters (i.e., radial gradient corrugation parameters for heat exchange fin 3 and scale texture parameters for scale texture 36); L_h, B1, B2, By, N_h, φ, d_in, d_out, and inner diameter expansion index are used as internal microchannel parameters (i.e., spatial oscillation parameters and expansion inner diameter parameters for spatial spiral oscillation expansion inner diameter microchannel 32). Based on the above parameters, a parameterized 3D model satisfying installation and manufacturing constraints is generated, and installation envelope, minimum wall thickness, minimum channel spacing, sealing boundary, powder discharge path, overhang angle, and post-processing accessibility constraints are applied.

[0059] S3, Multi-objective optimization and Pareto optimization: Set heat transfer performance, flow resistance, temperature uniformity, flow distribution uniformity and structural quality as optimization objectives, obtain performance data through simulation and / or experiment and perform multi-objective optimization, verify candidate structures, and output heat exchanger structural parameters that meet the constraints.

[0060] Specifically, the optimization objectives are to maximize the heat exchange capacity Q or heat exchange efficiency ε, minimize the pressure drop Δp_1 on the first heat exchange medium side, minimize the pressure drop Δp_2 on the second heat exchange medium side, minimize the wall temperature non-uniformity, minimize the flow distribution non-uniformity, and minimize the structural mass m (i.e., improve heat exchange capacity and uniformity, reduce pressure drop on both sides and structural mass). Meanwhile, the outlet temperature, maximum wall temperature, structural stress, mass, and manufacturing constraints are set as equality or inequality constraints.

[0061] Design variables can be represented as: x={c,n,θ,L,T1,A1,T2,A2,N,k,S_a,L_h,B1,B2,B_y,N_h,φ,d_in,d_out,q} Where c represents the configuration type, n represents the number of heat exchange zones or heat exchange plates, θ represents circumferential curvature, and q represents the dimensional parameters of the first medium transport channel and distribution orifice. For cases where discrete and continuous variables coexist, they can be encoded separately and then jointly optimized in the same optimization process; alternatively, configurations can be selected first, and then the continuous parameters of the selected configuration can be optimized.

[0062] Initial sample points are generated within a predefined design variable space (composed of configuration parameters, ripple period and amplitude, scale texture scale, microchannel spatial oscillation parameters, and gradually expanding inner diameter parameters) using Latin hypercube sampling, orthogonal experiments, uniform design, or other experimental design methods. Samples that do not meet geometric, sealing, or laser powder bed fusion (L-PBF) forming constraints are discarded during the modeling stage; for feasible samples, meshes and boundary conditions are automatically generated, and the geometric version, medium property model, solution settings, and convergence criteria are recorded.

[0063] Computational fluid dynamics simulations, conjugate heat transfer simulations, thermal-structural coupling simulations, and / or experimental tests are performed on each feasible sample to obtain performance indicators such as the outlet temperature of air or other second heat exchange medium, the outlet temperature of the first heat exchange medium, the heat transfer, pressure drop on both sides (including pressure drop on the first heat exchange medium side and pressure drop on the second heat exchange medium side), wall temperature distribution uniformity, flow distribution uniformity, structural stress, and mass. For modular configurations, the flow non-uniformity between individual heat exchange units is also evaluated; for integrated configurations, the circumferential flow and temperature distribution are also evaluated.

[0064] A mapping relationship between design variables and performance indicators in the design variable space is established based on sample data. This mapping relationship can employ response surface methodology, Kriging, Gaussian processes, radial basis functions, support vector regression, neural networks, or other surrogate models. Prediction error is evaluated through cross-validation or independent validation of samples. When the prediction error exceeds a preset threshold, additional samples are added and the surrogate model is updated in regions with large errors, near constraint boundaries, or near the current Pareto front.

[0065] Multi-objective optimization is performed within the feasible region that satisfies all constraints (installation envelope, minimum wall thickness, minimum channel spacing, sealing boundary, and laser powder bed fusion forming constraints). The multi-objective optimization algorithm can employ non-dominated sorting genetic algorithms, particle swarm optimization, differential evolution algorithms, Bayesian optimization, or other algorithms capable of outputting a non-dominated solution set. During optimization, candidate solutions are updated based on surrogate model predictions and necessary high-fidelity recalculated values ​​to obtain a Pareto candidate solution set (i.e., a set of mutually non-dominated optimal solutions, where improvement in any one solution necessarily leads to degradation of at least one other objective) among heat transfer enhancement, pressure drop, temperature uniformity, and structural quality.

[0066] Based on the system's allowable pressure drop, target outlet temperature, upper mass limit, and manufacturing margin, one or more candidate structures are selected from the Pareto candidate solution set, and verified using a refined mesh, high-fidelity property model, and / or prototype testing. If the verification results meet the preset technical indicators, the configuration, structural geometric parameters, manufacturing constraints, and performance data are output; if not, the process returns to step S2 to update or correct the parameter range of the design variables, surrogate model, or constraints, and step S3 is repeated to continue the iteration.

[0067] Figure 10 The process described herein is applicable to both the modular hydrogen intercooler of Example 1 and the integrated helium heat exchanger of Example 2. The media properties, boundary conditions, and target weights are adjusted according to the application scenario, but the optimization object is always the structural parameters of radially gradient corrugations, scale textures, spatially oscillating gradually expanding inner diameter microchannels, and modular or integrated configurations. This forms a closed-loop design method from operating condition input, configuration selection, parametric modeling, performance solving, multi-objective optimization to verification output.

[0068] The present invention provides a heat exchanger with dual-dimensional gradual corrugated synergistic heat exchange and its design method, which is particularly suitable for the intercooler embedded in the intermediate casing of hydrogen fuel cell aircraft engines, and can be extended to precoolers, regenerators, fuel or lubricating oil coolers, heat exchangers for fuel cell thermal management, as well as petrochemical, energy, marine, vehicle, electronic cooling and cryogenic engineering.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the embodiments of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A heat exchanger with dual-dimensional gradient corrugated synergistic heat exchange, comprising multiple heat exchange zones arranged circumferentially, characterized in that, The heat exchanger is formed by multiple heat exchange regions in a unit configuration that is independent and replaceable or in a continuous ring configuration that is integrated with each other; each heat exchange region includes an outer gas collection cavity section (1), an inner gas collection cavity section (2), and multiple heat exchange plates (3) disposed between the outer gas collection cavity section (1) and the inner gas collection cavity section (2); wherein, the Z direction is the radial direction of the heat exchange region, the Y direction is the axial direction of the heat exchange plate, and the X direction is the thickness direction of the heat exchange plate; The outer gas collection chamber section (1) includes a first medium inlet chamber (11) and a first medium outlet chamber (12) that are isolated from each other. The first medium inlet chamber (11) is connected to the inner gas collection chamber section (2) via a first medium conveying channel (21). The inner gas collection chamber section (2) is connected to the inlet of the heat exchange medium microchannel network inside each heat exchange plate (3). The outlet of the heat exchange medium microchannel network is connected to the first medium outlet chamber (12). The first heat exchange medium enters from the first medium inlet chamber (11), is distributed by the inner gas collection chamber section (2), and flows radially outward along the heat exchange medium microchannel network in the Z direction and converges to the first medium outlet chamber (12). An outer flow channel (33) is formed between adjacent heat exchange plates (3) for the second heat exchange medium to flow axially or near axially in the Y direction. The outer wall of the heat exchange plate (3) forms a radially gradient corrugated structure (31) and is provided with scale texture (36). The corrugation period and corrugation amplitude of the radially gradient corrugated structure (31) are radially gradient along the heat exchange area. The heat exchange medium microchannel network includes multiple oscillating gradually expanding inner diameter microchannels (32). The center line of the oscillating gradually expanding inner diameter microchannel (32) is radially mainstream in the Z direction, and forms in-plane waveforms in the first projection plane including the Z and Y directions and forms spatial oscillations in the second projection plane including the Z and X directions. The inner diameter of the oscillating gradually expanding inner diameter microchannel (32) gradually increases along the flow direction of the first heat exchange medium.

2. The heat exchanger according to claim 1, characterized in that, The multiple heat exchange areas are multiple independent heat exchange units equally distributed along the circumference. Any independent heat exchange unit can be removed and replaced while maintaining the installation status of the other independent heat exchange units. Each independent heat exchange unit is provided with an outer cavity unit partition (16) on both sides. The first medium conveying channel (21) is located inside the outer cavity unit partition (16) and / or inside the heat exchange plate (3). When the heat exchanger is used as an intercooler in the intermediate casing of an aero-engine, the multiple independent heat exchange units are respectively set in the sector defined by adjacent radial bearing plates. Each independent heat exchange unit is provided with at least one first medium inlet branch pipe (14) and at least one first medium outlet branch pipe (15). The heat exchange plate (3), the outer cavity unit partition (16) and the radial bearing plate are all arranged radially or nearly radially.

3. The heat exchanger according to claim 1, characterized in that, The multiple heat exchange zones are integrated and connected to form an overall annular structure without external cavity unit partitions. Multiple heat exchange plates (3) are continuously arranged in the circumferential direction and are set with circumferential bending to form a circumferentially continuous curved heat exchange plate array. The first medium conveying channel (21) is set inside the heat exchange plate (3) and connects the first medium inlet cavity (11) with the inner gas collection cavity section (2).

4. The heat exchanger according to claim 1, characterized in that, The corrugation period T_a(r) and corrugation amplitude A_a(r) of the radially tapered corrugated structure (31) satisfy the following governing equations: with the effective total length of the heat exchange plate (3) in the radial direction of the heat exchange region as L, establish radial coordinate r along the Z direction, 0≤r≤L, T_a(0)=T1, A_a(0)=A1, T_a(L)=T2, A_a(L)=A2; take the normalized variable t∈[0,1], the profile of the radially tapered corrugated structure (31) is determined by the following parametric equations: Z_a(t) = L·t, X_a(t)=[A1+(A2-A1)t]·sin(2π·N·t·k), Y_a(t)=0, Where Z_a(t) is the principal coordinate along the radial direction of the heat exchange region, X_a(t) is the corrugation offset along the thickness direction of the heat exchange plate, Y_a(t) is the corrugation offset along the axial direction of the heat exchange plate, N is the number of cycles within the length L, and k is the exponent of the radial change of wavelength.

5. The heat exchanger according to claim 1, characterized in that, The centerline of the oscillating, gradually expanding inner diameter microchannel (32) is described by the spatial parameter curve C(t)=(X_h(t),Y_h(t),Z_h(t)); the normalized variable t∈[0,1] is taken as follows: Z_h(t) = L_h·t, X_h(t)=[B1+(B2-B1)t]·sin(2π·N_h·t·k), Y_h(t)=B_y·sin(2π·N_h·t·k+φ), Where L_h is the effective length of the microchannel in the radial direction, Z_h(t) represents the advancing position of the main radial direction along the Z direction, Y_h(t) represents the in-plane waveform amplitude of the centerline along the heat exchanger axis in the YZ plane, X_h(t) represents the spatial oscillation amplitude of the centerline along the thickness direction of the heat exchanger in the XZ plane, B1 and B2 are the waveform amplitude parameters of the heat exchanger in the X direction, By is the oscillation amplitude parameter of the heat exchanger in the Y direction, N_h is the number of periods within the effective length of the microchannel in the radial direction, φ is the phase difference between the waveform displacement in the Y direction and the oscillation displacement in the X direction, and k is the exponent of the wavelength variation along the radial direction.

6. The heat exchanger according to claim 5, characterized in that, The phase difference φ is 90 degrees so that the oscillating gradually expanding inner diameter microchannel (32) forms a three-dimensional spiral or spiral-like oscillating flow channel inside the heat exchange plate (3); each oscillating gradually expanding inner diameter microchannel (32) in the same heat exchange plate (3) is arranged in a linear array along the axial direction, and ensures that the thickness of the solid wall in the X direction at any position is not less than 0.5 mm; the inner diameter d_h(s) of the oscillating gradually expanding inner diameter microchannel (32) gradually increases from the inlet inner diameter d_in to the outlet inner diameter d_out along the flow path arc length s, and d_out>d_in.

7. The heat exchanger according to claim 1, characterized in that, The scale texture (36) includes at least one of continuous or discretely arranged arc-shaped micro-protrusions, overlapping scale-like ridges, or biomimetic scale units; a heat insulation cavity (13) is provided between the first medium inlet cavity (11) and the first medium outlet cavity (12), and the heat insulation cavity (13) is a hollow structure or is provided with a low thermal conductivity cell structure.

8. The heat exchanger according to claim 1, characterized in that, Each independent heat exchange unit in the mutually independent and replaceable unit configuration or the continuous ring configuration is an integrated continuous structure for laser powder bed fusion additive manufacturing. The outer gas collection cavity section (1), the inner gas collection cavity section (2), the heat exchange plate (3), the heat exchange medium microchannel network, the first medium transport channel (21), and the outer cavity unit partition (16) set in the unit configuration are integrally formed by laser powder bed fusion. The outer gas collection chamber section (1), the inner gas collection chamber section (2) and the heat exchange plate (3) adopt a rounded corner transition or variable thickness transition structure, and a connecting path for powder discharge after forming is provided between the heat exchange medium microchannel network, the first medium conveying channel (21) and the external branch pipe.

9. A design method for a heat exchanger with dual-dimensional gradient corrugated synergistic heat transfer, characterized in that, Includes the following steps: S1. Based on the installation envelope, support and sealing boundary, heat exchange conditions and heat exchange medium, determine the independent and replaceable unit configuration or the continuous ring configuration that is integrated with each other. Determine the number of heat exchange areas, circumferential arrangement, initial size of outer gas collection cavity section (1), inner gas collection cavity section (2), heat exchange plate (3) and first medium conveying channel (21), and establish the heat exchange flow path between the first heat exchange medium and the second heat exchange medium. S2, determine the radial gradient ripple parameters, scale texture (36) parameters, and spatial oscillation parameters and gradually expanding inner diameter parameters of the oscillating gradually expanding inner diameter microchannel (32) of the heat exchange plate (3), and generate a parametric three-dimensional model that meets the installation and manufacturing constraints; S3 sets heat transfer performance, flow resistance, temperature uniformity, flow distribution uniformity, and structural quality as optimization objectives. It obtains performance data through simulation and / or experiments and performs multi-objective optimization to verify candidate structures and output heat exchanger structural parameters that meet the constraints.

10. The design method according to claim 9, characterized in that, Step S3 includes: Sample points were generated in a design variable space consisting of configuration parameters, ripple period and amplitude, scale texture scale, microchannel spatial oscillation parameters, and gradually expanding inner diameter parameters using experimental design methods. Through computational fluid dynamics simulation, thermal-structure coupling simulation and / or experimental testing, the heat transfer, outlet temperature, pressure drop on the first heat transfer medium side, pressure drop on the second heat transfer medium side, wall temperature uniformity, flow distribution uniformity and structural mass of each sample point are obtained. Establish the mapping relationship between design variables and performance data in the design variable space, and perform multi-objective optimization under the conditions of satisfying the installation envelope, minimum wall thickness, minimum channel spacing, sealing boundary and laser powder bed melting forming constraints to obtain the Pareto candidate solution set; Candidate structures are selected from the Pareto candidate solution set and verified by high-fidelity simulation and / or experiment. When the verification result does not meet the preset index, return to step S2 to update the parameter range and repeat step S3.

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