Hydrogen energy aircraft fuel stack thermal management system and skin heat exchanger design method

Abstract

The invention discloses a hydrogen energy aircraft fuel stack thermal management system and a skin heat exchanger design method, and belongs to the technical field of aircraft thermal management. The method comprises the following steps: constructing a multi-physical field coupling simulation model of the skin heat exchanger for simulating pneumatic, heat transfer and structural mechanical behaviors of the skin heat exchanger in a flight state; the geometric parameter set of the air side microstructure of the skin heat exchanger and the geometric parameter set of the internal cooling liquid flow channel are jointly defined as a design variable space; the set optimization targets comprise the maximization of the total heat exchange amount, the minimization of the aerodynamic resistance increment caused by the skin heat exchanger and the minimization of the system total weight of the skin heat exchanger; and generating a Pareto optimal solution set based on an iterative search result by applying a multi-objective optimization algorithm. According to the method, the internal and external structures of the skin heat exchanger can be optimally designed under a multi-physics field coupling framework, and the optimal balance point among a plurality of mutual restriction targets is balanced and sought.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aircraft thermal management, in particular to a hydrogen energy aircraft fuel cell thermal management system and a skin heat exchanger design method. BACKGROUND

[0002] Under the background of increasingly severe global climate change challenges, the aviation industry, as one of the important sources of carbon emissions, is actively seeking a sustainable development path. Among many explorations, hydrogen energy, with its outstanding mass energy density and environmental friendliness, has become the core candidate technology for future green aviation power. It is particularly worth noting that hydrogen fuel cells, especially proton exchange membrane fuel cells, are widely considered as the ideal choice for driving the next generation of regional aircraft, unmanned aerial vehicles, and even auxiliary power units, due to their low emissions, high efficiency, fast response, and relatively quiet operation characteristics in aviation applications.

[0003] However, integrating megawatt-level hydrogen fuel cell systems into aviation platforms faces many challenges, one of the core bottlenecks being that during operation, about 40% to 50% of the chemical energy of the fuel cell stack is released in the form of waste heat. For aviation-level power systems, this means that hundreds of kilowatts to megawatts of heat load need to be handled. This part of waste heat needs to be efficiently discharged to maintain the stable operation of the stack within the optimal temperature window. Insufficient heat dissipation will lead to irreversible damage such as proton exchange membrane dehydration and catalyst sintering, endangering the operation safety; while excessive cooling will reduce the reaction efficiency and output power. Therefore, it is necessary to develop a high-efficiency, reliable and lightweight thermal management system.

[0004] Currently, aviation fuel cell thermal management generally uses a liquid cooling circulation system, which absorbs waste heat through cooling liquid flowing through the internal channels of the stack, and then discharges the heat to the external environment through a heat exchanger. In this system, the performance and form of the heat exchanger directly determine the efficiency, weight and impact on the overall performance of the aircraft of the entire thermal management system. Traditional aviation fuel cell thermal management heat exchangers mostly use ram air heat exchangers, which introduce external cold air for forced convection heat transfer through special air inlets or air outlets, but the air inlets and outlets will damage the aerodynamic shape, causing significant additional drag, and independent components occupy valuable space and increase weight. The conceptually forward skin heat exchanger integrates the cooling flow channel into the load-bearing skin of the aircraft fuselage or wing, utilizing its broad surface area for heat dissipation, which can theoretically eliminate additional drag, reduce weight and improve integration.

[0005] However, the skin heat exchanger still faces some problems in actual design and application: first, to enhance heat exchange, a disturbance structure needs to be set on the skin surface, which will increase the aerodynamic friction resistance; on the contrary, designing a smooth surface to reduce resistance will weaken the heat exchange. Second, the design of the external air side heat exchange structure and the internal cooling liquid flow path is often independent of each other, resulting in a mismatch between the internal and external heat exchange capacities, forming a heat transfer bottleneck, and it is difficult to achieve optimal performance. In addition, the skin heat exchanger is a system with strong coupling of flow field, temperature field and stress field, and changes in flight state will cause complex interactions among multiple physical fields, such as changes in Mach number and angle of attack, which will dynamically affect the external flow field and internal heat distribution, and thermal stress may cause structural deformation, which will react on the aerodynamic shape. Traditional design methods are difficult to control such complex interactions, resulting in long design cycle, difficult balance between internal and external design, and other problems. SUMMARY

[0006] The purpose of the present application is to overcome the problems in the prior art, provide a hydrogen energy aircraft fuel cell thermal management system and a skin heat exchanger design method, which can optimize the internal and external structure of the skin heat exchanger under the framework of multi-physical field coupling, and balance and seek the best balance point among multiple mutually restrictive objectives.

[0007] The optimization design method of the aircraft skin heat exchanger of the present application comprises the following steps: constructing a multi-physical field coupling simulation model of the aircraft skin heat exchanger, the model at least integrating a computational fluid dynamics CFD model, a computational heat transfer CHT model and a structural mechanics CSD model, for simulating the aerodynamic, heat transfer and structural mechanics behavior of the skin heat exchanger in flight state; The geometric parameter set of the air side microstructure of the skin heat exchanger and the geometric parameter set of the internal cooling liquid flow path are collectively defined as a design variable space; at least three mutually restrictive optimization objectives are set, including maximizing the total heat exchange, minimizing the aerodynamic drag increment caused by the skin heat exchanger, and minimizing the total weight of the system of the skin heat exchanger; a multi-objective optimization algorithm is used to automatically iteratively search in the design variable space, for each set of design variables, the corresponding optimization objective value is calculated by the multi-physical field coupling simulation model; based on the results of the iterative search, a Pareto optimal solution set is generated, wherein each solution represents a parameter combination of a skin heat exchanger design scheme that balances among the multiple optimization objectives.

[0008] In the step of defining the design variable space, the geometric parameters of the air side microstructure and the geometric parameters of the internal cooling liquid flow path are defined in association, so that the multi-objective optimization algorithm optimizes the internal and external geometric parameters simultaneously in the search process.

[0009] Preferably, the set of geometric parameters of the air-side microstructure includes multiple parameters among its height, pitch, thickness, cross-sectional shape, arrangement density and angle of incidence; and the set of geometric parameters of the internal coolant channel includes multiple parameters among its hydraulic diameter, channel pitch, cross-sectional shape, flow direction angle and distribution density.

[0010] Preferably, the skin heat exchanger is divided into multiple design regions according to its position on the aircraft, and the design variable space and / or different constraint conditions are defined independently for different regions, the constraint conditions including temperature constraint, structural strength constraint, geometric constraint and manufacturing feasibility constraint; to achieve customized optimization of local aerodynamics, thermal load and structural requirements.

[0011] Preferably, the multi-objective optimization algorithm is a non-dominated sorting genetic algorithm NSGA-II or a multi-objective particle swarm optimization algorithm.

[0012] The application also provides a skin heat exchanger of an aircraft designed by the above-mentioned optimization design method.

[0013] The application also provides a stack thermal management system comprising the skin heat exchanger of an aircraft designed by the above-mentioned optimization design method, the stack thermal management system comprising a fuel stack; a coolant circulation loop connected to the fuel stack; a skin heat exchanger connected to the coolant circulation loop; wherein the skin heat exchanger is a skin heat exchanger optimized by the above-mentioned method, and the skin heat exchanger constitutes a load-bearing skin structure of the aircraft fuselage or wing.

[0014] Preferably, the skin heat exchanger comprises: an outer surface heat exchange layer having an outer surface distributed with air-side microstructures optimized by the above-mentioned optimization design method; an internal coolant channel layer integrated with the outer surface heat exchange layer through an integrated manufacturing process, the flow channel of which is optimized by the above-mentioned optimization design method; wherein the geometric features of the air-side microstructure and the geometric features of the internal coolant channel are matched in thermodynamics and geometry based on the optimization design method.

[0015] Preferably, the air-side microstructure is a three-dimensional twisted fin with a single-cycle twist angle θ of 30°-60° and a ratio of twist wavelength to height of 0.5-2.5.

[0016] Preferably, the internal coolant channel layer is a multi-stage fractal tree-shaped channel network comprising a primary main channel, secondary branch channels diverging from the primary main channel, and tertiary microchannels diverging from the secondary branch channels and covering at least 80% of the area of the outer surface heat exchange layer.

[0017] Compared with the prior art, the application has the following beneficial effects: The application firstly proposes a systematic and collaborative optimization design method based on multi-physics field coupling simulation and multi-objective optimization algorithm.

[0018] The application realizes real internal-external collaborative design by synchronously defining the geometric parameters of the air side and the cooling liquid side as design variables and performing associated optimization, ensures the matching of the internal-external heat exchange capacity, avoids the heat transfer bottleneck, and breaks through the performance upper limit of traditional serial design or isolated design.

[0019] The application meets the fuel cell stack rated and peak heat dissipation requirements, maximally reduces the adverse effects on the overall aerodynamic shape of the aircraft, improves the system integration and lightweight level, improves the aerodynamic efficiency of the aircraft, and optimizes the overall energy efficiency of the aircraft.

[0020] The three-dimensional twisted fin and fractal tree-shaped flow channel combined structure obtained by the application has excellent characteristics of low flow resistance, high heat exchange and lightweight, and fully verifies the effectiveness and advancement of the method. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a whole structure diagram of the aircraft fuel cell thermal management system of the embodiment of the application.

[0022] Figure 2 It is a cross-sectional view perpendicular to the incoming flow direction in the aircraft level flight state of the embodiment of the application. Figure 3 It is a schematic view of the internal cooling liquid flow channel layer of the embodiment of the application.

[0023] REFERENCE SIGNS: 1, fuel cell; 2, cooling liquid circulation loop; 3, skin heat exchanger; 4, heat spreading plate; 5, cooling liquid; 6, microstructure fin; 7, primary main channel; 8, secondary branch channel; 9, tertiary microchannel. DETAILED DESCRIPTION

[0024] To make the purpose, technical scheme and advantages of the embodiment of the application clearer, the technical scheme of the embodiment of the application will be described clearly and completely below in combination with the drawings of the embodiment of the application. Obviously, the described embodiment is a part of the embodiments of the application, rather than all the embodiments. Based on the described embodiments of the application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0025] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” indicate that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; when the absolute position of the described objects changes, the relative positional relationship may also change accordingly.

[0026] This invention provides a multi-objective, multi-physics-based collaborative optimization method for skin heat exchanger design, particularly suitable for parameter optimization under complex flight conditions to achieve optimal performance. The method first focuses on establishing a multi-physics coupled simulation model. For the skin heat exchanger system, a computational fluid dynamics (CFD) model is developed or integrated to accurately simulate the external airflow field and internal coolant flow field, including velocity field, pressure field, turbulence characteristics, boundary layer development, etc. Simultaneously, a computational heat transfer (CHT) model is integrated to capture heat conduction within the skin material, convection from the outer surface of the skin to the air, convection from the inner surface of the skin to the coolant, and radiative heat transfer processes. A structural mechanics (CSD) model is also considered to evaluate the structural strength, thermal stress, and deformation of the skin. The structural strength, stress distribution, deformation, and fatigue life of the skin heat exchanger under aerodynamic, thermal stress, and internal cooling hydraulic loads are estimated. Based on this, key geometric parameters and material properties of the air-side microstructure fins 6 of the skin heat exchanger (such as fin height h, length L, spacing s, thickness t, and flow angle α) and the internal coolant flow channels (flow channel cross-sectional dimensions W×H, spacing P, and flow direction angle θ) are selected as design variables. Simultaneously, reasonable value ranges and discretization strategies for these design variables are defined, constituting the design space. Design variables can be defined in partitions according to different design regions to achieve local optimization.

[0027] To achieve a balance across multiple performance metrics, at least three mutually constraining optimization objectives are set: maximizing total heat transfer to ensure efficient removal of waste heat generated by the fuel cell stack and fully meeting its heat dissipation requirements; minimizing aerodynamic drag increment to reduce the additional drag ∆D of the skin heat exchanger relative to the smooth skin; and minimizing total system weight, encompassing the weight of the skin heat exchanger body structure materials and the internal coolant. Additionally, minimizing internal pumping power consumption can be considered as an optional optimization objective to improve system energy efficiency.

[0028] During the optimization process, this method imposes strict constraints to ensure the feasibility and reliability of the design. These constraints include temperature constraints, such as the fuel stack outlet coolant temperature must be below a certain critical value, and the maximum temperature of the skin heat exchanger material must not exceed its allowable temperature. Structural strength constraints require that the stress and strain values ​​of the skin under maximum aerodynamic loads, thermal stresses, and internal pressure loads must not exceed the material's yield strength or service strength, and must meet certain safety margins. Geometric constraints stipulate that the total thickness of the skin, the height of the microstructure fins, etc., must not exceed the limits of the aircraft's aerodynamic or structural design. In addition, manufacturing feasibility constraints require that the minimum dimensions of the flow channels, wall thickness, etc., should meet current or foreseeable future manufacturing capabilities.

[0029] The process employs the advanced multi-objective optimization algorithm NSGA-II to perform efficient iterative searches within a defined design space. The aforementioned multiphysics coupled simulation model is used to evaluate the objective function values ​​and constraint satisfaction under different combinations of design variables. Through continuous evolution and iteration, the algorithm explores design schemes that achieve a good balance between competing optimization objectives.

[0030] The optimization process ultimately generates a Pareto optimal solution set containing a series of trade-off solutions. Each point in this solution set represents an optimal design, meaning that no objective can be further improved without sacrificing other objectives. Based on specific flight mission requirements, economic considerations, safety levels, or other high-level indicators, the most suitable collaborative design scheme is selected from this Pareto solution set.

[0031] This invention achieves a balance between heat exchange and aerodynamic performance. Through optimized internal and external design, it fundamentally eliminates the enormous aerodynamic drag of traditional ramjet cooling, achieving a combination of efficient heat dissipation and minimal additional drag, significantly improving the aerodynamic efficiency and energy efficiency of the aircraft.

[0032] The skin heat exchanger design method and the designed skin heat exchanger of this invention are not only applicable to heat dissipation of fuel cell stacks in hydrogen-powered aircraft, but can also be extended to other fields with strict requirements for lightweight, high efficiency and high integration, such as cooling of avionics equipment, thermal management of energy storage batteries and aerodynamic heating protection of high-speed aircraft, etc., and have broad application prospects and market potential.

[0033] Furthermore, embodiments of the present invention also propose a thermal management system for a fuel cell stack in a hydrogen-powered aircraft, such as... Figure 1As shown, the system comprises a fuel cell stack 1, a coolant circulation loop 2, and a skin heat exchanger 3. The fuel cell stack 1 generates a large amount of waste heat during power generation, which is collected by the coolant circulation loop 2. The coolant circulation loop 2 typically consists of a coolant circulation pump, internal cooling channels within the fuel cell stack, coolant piping, and the skin heat exchanger 3, optimized according to this invention. Driven by the coolant circulation pump, the high-temperature coolant flows through the internal cooling channels of the fuel cell stack 1 to absorb heat, and then enters the skin heat exchanger 3 through the coolant piping. In the skin heat exchanger 3, the coolant transfers heat to the air outside the aircraft, and the cooled coolant returns to the coolant circulation pump, forming a closed-loop circulation, thereby continuously and stably maintaining the operating temperature of the fuel cell stack 1.

[0034] The skin heat exchanger 3 of this invention is integrated into the surface of an aircraft, such as the wing or fuselage skin, as part of the aircraft's load-bearing structure. The above design of this invention eliminates the additional space and weight required by traditional independent heat exchangers and maintains the aircraft's smooth aerodynamic shape to the greatest extent possible. The skin heat exchanger 3 of this invention is mainly composed of a tightly integrated outer surface heat exchange layer and an internal coolant flow channel layer.

[0035] The outer surface heat exchange layer forms the interface between the skin heat exchanger and the external airflow, constituting the aerodynamic shape of the aircraft. This layer is designed with and arranged a series of air-side microstructure fins 6. These microstructure fins 6 are not simply roughened surfaces, but rather rigorously aerodynamically and thermodynamically optimized designs. Their morphologies can include low-drag airfoil fins, wave-shaped or pitted arrays, or specific three-dimensional structures generated through topology optimization, aiming to achieve the optimal balance between aerodynamic and heat transfer performance. For example, the longitudinal vortex generator fins used in this embodiment, by optimizing their shape and distribution, achieve efficient heat transfer while keeping the increase in aerodynamic friction drag within an acceptable range.

[0036] The outer surface heat exchange layer features a series of air-side microstructure fins or integrated perturbation structures designed and arranged along the airflow direction or at a specific angle. These microstructures are not simple protrusions, but rather precisely calculated and optimized designs that may include, but are not limited to, low-drag airfoils, wave-like shapes, asymmetric recesses, or specific topological morphologies. Their function is to precisely perturb the boundary layer on the aircraft surface locally, promoting the transition from laminar to turbulent flow or enhancing turbulent mixing, thereby significantly improving the surface convective heat transfer coefficient while strictly controlling the resulting increase in frictional drag to a minimum. Their geometric parameters, including height, spacing, thickness, cross-sectional shape, arrangement density, and angle of attack, are all customized and zoned according to their specific location on the skin surface, local airflow velocity, pressure gradient, and boundary layer characteristics.

[0037] In this embodiment, the geometric parameters of the microstructure fins 6, such as height, spacing, and thickness, are key design variables of the collaborative optimization method of this invention. These parameters will be customized according to the specific location of the skin heat exchanger on the aircraft, the local airflow velocity, pressure gradient, and boundary layer development characteristics. For example, in regions with high airflow velocity and thin boundary layer, smaller microstructures can be used to avoid excessive drag; while in regions with low airflow velocity or thick boundary layer, larger structures or structures with stronger turbulence capabilities can be used to effectively enhance heat transfer.

[0038] The internal coolant channel layer is tightly integrated with one side of the outer surface heat exchange layer, forming a unified structure for guiding the flow of high-temperature coolant from the fuel cell stack. This layer consists of a series of precisely arranged coolant channels designed to carry and guide the flow of high-temperature coolant from the fuel cell stack. These channels can be structured as microchannel arrays, macrochannel networks, or a micro-macro composite channel structure combining the advantages of both.

[0039] The cross-sectional shape of the coolant channels (e.g., rectangular, elliptical, trapezoidal, teardrop-shaped), hydraulic diameter, channel spacing, and flow direction (which can be straight, S-shaped, or at a specific angle to the external airflow direction) are all key design variables in the collaborative optimization method of this invention. The design goal is to ensure that the coolant effectively absorbs heat while achieving uniform flow distribution, avoiding localized overheating or undercooling areas, and minimizing the total pressure drop and the pumping power consumption of the coolant circulation pump. In areas with high localized heat loads, the coolant channels can be designed to be denser or use higher flow velocities; in areas requiring low pressure drop, larger channel cross-sections or straighter flow directions can be used.

[0040] In this embodiment of the invention, the air-side microstructure fins 6 of the outer surface heat exchange layer and the coolant channels of the internal coolant flow channel layer are not designed independently, but are tightly integrated through an advanced integrated manufacturing process to form a multi-layer composite structure. This internal and external design aims to achieve geometric and thermodynamic matching. In this embodiment, the heat exchange enhancement design on the outer air side and the heat exchange capacity on the internal coolant side are closely related and optimized synchronously. In areas of the aircraft skin surface with high heat flux density or urgent local heat exchange needs, the turbulence intensity of the air-side microstructure fins can be increased, for example, by increasing the height or density, or by adjusting the density or local flow velocity of the internal coolant flow channels, to correspondingly increase the heat exchange capacity. Conversely, in areas sensitive to aerodynamic drag (such as the wing leading edge), the design prioritizes drag reduction, and the microstructure size and density will be reduced accordingly. Through this coupled design of internal and external geometry and heat flow, the performance bottleneck caused by traditional single-side optimization is overcome.

[0041] As an example, the optimized microstructure of the air side of the skin heat exchanger in this embodiment is a three-dimensional twisted fin with a single-cycle twist angle θ of 30°~60° and a twist wavelength to height ratio of 0.5~2.5. The internal coolant flow channel layer is a multi-level fractal tree-like flow channel network, including a primary main channel 7, a secondary branch channel 8 branching from the primary main channel, and a tertiary microchannel 9 branching from the secondary branch channel 8 and covering at least 80% of the outer surface heat exchange layer.

[0042] More specifically, 3D printing techniques, such as selective laser melting (SLM) for metals, electron beam melting (EBM) for metals, or 3D printing of polymer materials, can be used to integrally form skins with complex internal flow channels and external microstructures. For composite material skins, microchannel frameworks or external microstructures can be pre-placed during the layup process and then solidified integrally. Metal skins can be formed by stacking pre-processed thin plates, etching flow channels and microstructures, and then performing high-precision brazing or diffusion bonding to create a seamless, integral structure. Furthermore, micromachining techniques such as laser etching and electrical discharge machining can also be used to manufacture intricate microstructures and flow channels on or inside the skin surface. The specific choice depends on a combination of factors, including the skin material, design precision requirements, and manufacturing costs.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An optimized design method for an aircraft skin heat exchanger, characterized in that, Includes the following steps: A multiphysics coupled simulation model of an aircraft skin heat exchanger is constructed. The model integrates at least a computational fluid dynamics (CFD) model, a computational heat transfer (CHT) model, and a structural mechanics (CSD) model to simulate the aerodynamic, heat transfer, and structural mechanical behavior of the skin heat exchanger in flight. The set of geometric parameters of the air-side microstructure of the skin heat exchanger and the set of geometric parameters of the internal coolant flow channel are jointly defined as the design variable space. At least three mutually constraining optimization objectives are set, including maximizing the total heat transfer, minimizing the aerodynamic drag increment caused by the skin heat exchanger, and minimizing the total system weight of the skin heat exchanger. A multi-objective optimization algorithm is used to automatically iteratively search within the design variable space. For each set of design variables, the corresponding optimization objective value is calculated using the multiphysics coupled simulation model. Based on the results of the iterative search, a Pareto optimal solution set is generated, where each solution represents a combination of parameters for a skin heat exchanger design that achieves a balance among the multiple optimization objectives.

2. The optimized design method for an aircraft skin heat exchanger as described in claim 1, characterized in that, The set of geometric parameters of the air-side microstructure includes multiple parameters such as its height, spacing, thickness, cross-sectional shape, arrangement density, and flow-facing angle; the set of geometric parameters of the internal coolant flow channel includes multiple parameters such as its hydraulic diameter, channel spacing, cross-sectional shape, flow direction angle, and distribution density.

3. The optimized design method for an aircraft skin heat exchanger as described in claim 1, characterized in that, Based on the location of the skin heat exchanger on the aircraft, it is divided into multiple design regions, and design variable spaces are defined independently for different regions and / or different constraints are applied, including temperature constraints, structural strength constraints, geometric constraints, and manufacturing feasibility constraints.

4. The thermal management system for hydrogen-powered aircraft fuel stacks as described in claim 1, characterized in that, The multi-objective optimization algorithm is either the non-dominated sorting genetic algorithm NSGA-II or the multi-objective particle swarm optimization algorithm.

5. A heat exchanger for aircraft skin, characterized in that, The skin heat exchanger is designed using the optimization design method as described in any one of claims 1 to 4.

6. A thermal management system for a hydrogen-powered aircraft fuel cell stack, characterized in that, include: Fuel cell stack; A coolant circulation loop is connected to the fuel stack; A skin heat exchanger is connected to the coolant circulation loop; wherein the skin heat exchanger is the aircraft skin heat exchanger as described in claim 5, and constitutes the load-bearing skin structure of the aircraft fuselage or wing.

7. The thermal management system for a hydrogen-powered aircraft fuel stack as described in claim 6, characterized in that, The skin heat exchanger includes: An outer surface heat exchange layer has air-side microstructures optimized by the aforementioned optimization design method distributed on its outer surface; an inner coolant flow channel layer is integrated with the outer surface heat exchange layer through an integrated manufacturing process, and its flow channels are optimized by the aforementioned optimization design method; wherein, the geometric features of the air-side microstructures and the geometric features of the inner coolant flow channels achieve thermodynamic and geometric matching based on the aforementioned optimization design method.

8. The thermal management system for a hydrogen-powered aircraft fuel stack as described in claim 7, characterized in that, The air-side microstructure is a three-dimensional twisted fin with a single-cycle twist angle θ of 30°~60° and a twist wavelength to height ratio of 0.5~2.

5.

9. The thermal management system for a hydrogen-powered aircraft fuel cell stack as described in claim 7, characterized in that, The internal coolant flow channel layer is a multi-level fractal tree-like flow channel network, including a primary main channel, secondary branch channels branching from the primary main channel, and tertiary microchannels branching from the secondary branch channels and covering at least 80% of the area of ​​the outer surface heat exchange layer.

Images