A multi-assembled high porosity phase change double-layer porous plate sweating cooling structure

Abstract

This disclosure provides a multi-combination high-porosity phase change double-layer porous plate sweating cooling structure, comprising: a fluid domain with a flow guiding structure for distributing cooling medium; and a double-layer porous medium domain disposed above the fluid domain for receiving cooling medium from the fluid domain. The double-layer porous medium domain consists of a first layer porous medium domain and a second layer porous medium domain. The first and second layers are composed of any two different types selected from Gyroid-type porous media, fibrous porous media, and granular porous media, and the porosity of all porous media in the double-layer porous medium domain is not less than 0.7. This disclosure, through the complementary advantages of multiple types of porous media, the high porosity and equal-thickness double-layer structure design, and the functional zoning configuration, combined with the efficient utilization of latent heat of phase change, significantly reduces the maximum temperature of the solid matrix and the temperature oscillation amplitude, resulting in a cooling effect superior to traditional single-layer plate structures.

Description

Technical Field

[0001] This disclosure relates to the field of sweating and cooling technology, and in particular to a multi-combination high-porosity phase change double-layer porous plate sweating and cooling structure. Background Technology

[0002] Sweating cooling technology utilizes the high specific surface area and permeability of porous media to allow the cooling medium to seep out from the porous walls, forming a continuous cooling gas film on the heated surface. This is a key technology for achieving thermal protection of high-temperature components through a combination of gas film insulation and convective heat transfer. Its cooling performance is closely related to the structural characteristics of the porous media (porosity, permeability, pore morphology, etc.) and the thermophysical properties of the cooling medium. It is widely used in components operating in extreme thermal environments, such as aerospace vehicles, aero-engine combustion chambers, and gas turbine blades.

[0003] Traditional sweating cooling structures often employ a single type of porous medium, such as granular porous media made from sintered metal or ceramic particles, or fibrous porous media formed from interwoven metal or ceramic fibers. However, single-type porous media have inherent drawbacks: while granular porous media have a large heat exchange area, their poor pore connectivity can easily lead to obstructed cooling medium flow and limited sweating efficiency; fibrous porous media have better pore connectivity, but their uneven pore distribution can easily result in excessively rapid localized penetration of the cooling medium and discontinuous gas film coverage.

[0004] In recent years, Gyroid-type porous media constructed based on the TPMS (Triply Periodic Minimal Surface) method have been proposed. They have the characteristics of continuous and interconnected pores, strong structural periodicity, and excellent mechanical properties. However, when used alone, they still have the defects of insufficient gas film stability and limited heat transfer enhancement effect near the wall.

[0005] During atmospheric reentry or high-speed flight, the surface of aerospace vehicles will be subjected to extreme aerodynamic heating of 1500-3000℃, with a heat flux density reaching 1×10⁻⁶. 6 -5×10 6 W / m 2 This places extremely high demands on the cooling efficiency, temperature uniformity, and structural reliability of thermal protection technologies. Existing single-porous-medium sweating cooling structures cannot simultaneously meet the three core requirements of rapid cooling medium penetration, efficient heat exchange, and stable film formation, and do not fully utilize the latent heat of phase change of the cooling medium, making it difficult to meet the extreme thermal protection requirements of aerospace vehicles. Furthermore, existing technologies lack bilayer structures that combine Gyroid, fibrous, and granular porous media in pairs (including interchangeable upper and lower structures), failing to achieve comprehensive performance optimization through the complementary advantages of different types of porous media. They also lack dedicated flow-guiding structures for cooling medium distribution, resulting in uneven medium distribution and limited cooling effect.

[0006] The information disclosed in the background section is only for enhancing the understanding of the background of this invention, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this disclosure provides a multi-combination high-porosity phase change double-layer porous plate sweating cooling structure. Through the combined design of multiple types of porous media, the configuration of high porosity and equal-thickness double-layer structure, and the optimization of flow distribution, combined with the efficient utilization of the latent heat of liquid water phase change, a significant improvement in sweating cooling performance is achieved.

[0008] This disclosure provides the following technical solutions:

[0009] A multi-combination high-porosity phase change double-layer porous plate sweating cooling structure includes:

[0010] The fluid domain contains a flow guiding structure for distributing the cooling medium.

[0011] A double-layer porous medium domain disposed above the fluid domain is used to receive cooling medium from the fluid domain. The double-layer porous medium domain is composed of a first layer porous medium domain and a second layer porous medium domain.

[0012] The first porous medium domain and the second porous medium domain are selected from any two different types of porous media, namely Gyroid type porous media, fiber type porous media and particle type porous media, and the porosity of all porous media in the dual-layer porous medium domain is not less than 0.7.

[0013] In the aforementioned structure, the two different types are: a combination of Gyroid-type porous media and granular porous media; or a combination of fiber-type porous media and granular porous media; or a combination of fiber-type porous media and Gyroid-type porous media.

[0014] In the aforementioned structure, the Gyroid-type porous medium is constructed using a triple-periodic minimal surface method, and has a continuously interconnected periodic network pore structure.

[0015] In the aforementioned structure, the fibrous porous medium is a structure formed by interwoven metal fibers or ceramic fibers and having interconnected pores.

[0016] In the aforementioned structure, the particulate porous medium is a structure with interstitial pores formed by sintering metal particles or ceramic particles.

[0017] In the structure described, the thicknesses of the first porous dielectric domain and the second porous dielectric domain are equal.

[0018] In the structure described, the first porous medium domain and the second porous medium domain are fixedly connected by diffusion welding or high-temperature sintering process, and the porosity of the connection surface is not less than 90%.

[0019] In the aforementioned structure, the flow guiding structure inside the fluid domain is a flow guiding wall, which is used to divide the fluid domain into multiple independent flow channels.

[0020] In the aforementioned structure, the cooling medium is liquid water. After flowing through the fluid domain and being distributed, it enters the double-layer porous medium domain to permeate and undergo vaporization phase change, thereby utilizing the latent heat of phase change to enhance heat transfer and cooling.

[0021] The structure described herein is used for thermal protection of high-temperature components on the surface of aerospace vehicles, the combustion chamber of aircraft engines, or the blades of gas turbines.

[0022] Compared with the prior art, the beneficial effects of this disclosure are as follows:

[0023] This disclosure provides a multi-combination high-porosity phase change double-layer porous plate sweating cooling structure. Through the complementary advantages of multiple types of porous media, the design of a high-porosity and equal-thickness double-layer structure, and the configuration of functional zones, combined with the efficient utilization of the latent heat of phase change, the maximum temperature and stable temperature of the solid matrix are significantly reduced, the temperature oscillation amplitude is significantly reduced, and the overall cooling effect is better than that of the traditional single-layer plate structure, thus achieving a significant improvement in sweating cooling performance.

[0024] The description provided is merely an overview of the technical solution disclosed herein. In order to make the technical means of this disclosure clearer and more understandable, to the point that those skilled in the art can implement it according to the contents of the specification, and in order to make the described and other objects, features and advantages of this disclosure more obvious and understandable, specific embodiments of this disclosure are illustrated below. Attached Figure Description

[0025] Various other advantages and benefits of this disclosure will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0026] Figure 1 A schematic diagram of the microstructure of the Gyroid-type porous medium constructed using the TPMS method provided in this disclosure;

[0027] Figure 2 A schematic diagram of the microstructure of the fibrous porous media provided in this disclosure;

[0028] Figure 3 This is a schematic diagram of the microstructure of the particulate porous media provided in this disclosure;

[0029] Figure 4 This is a schematic cross-sectional view of the multi-combination high-porosity phase change double-layer porous plate sweating and cooling structure provided in this disclosure.

[0030] Figure 5 A comparison graph of solid matrix temperature change over time (0-20 seconds) in different cooling structures provided in this disclosure;

[0031] Figure 6 A comparison of the solid matrix temperature change over time (20-40 seconds) in different cooling structures provided in this disclosure. Detailed Implementation

[0032] The following will be combined with the appendix Figures 1 to 6 The embodiments described herein are provided in detail and are intended to explain, rather than limit, this disclosure. While specific embodiments of this disclosure are shown in the accompanying drawings, it should be understood that this disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0033] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions of preferred embodiments of this disclosure are for the purpose of implementing the general principles of the specification and are not intended to limit the scope of this disclosure. The scope of protection of this disclosure is determined by the appended claims.

[0034] To facilitate understanding of the embodiments of this disclosure, the following will provide further explanation and description with reference to the accompanying drawings and several specific embodiments, and the accompanying drawings do not constitute a limitation on the embodiments of this disclosure.

[0035] A multi-combination high-porosity phase change double-layer porous plate sweating cooling structure includes:

[0036] The fluid domain contains a flow guiding structure for distributing the cooling medium.

[0037] A double-layer porous medium domain disposed above the fluid domain is used to receive cooling medium from the fluid domain. The double-layer porous medium domain is composed of a first layer porous medium domain and a second layer porous medium domain.

[0038] The first porous medium domain and the second porous medium domain are selected from any two different types of porous media, namely Gyroid type porous media, fiber type porous media and particle type porous media, and the porosity of all porous media in the dual-layer porous medium domain is not less than 0.7.

[0039] In this embodiment, by leveraging the complementary advantages of multiple types of porous media, the design of a double-layer structure with high porosity and equal thickness, and the configuration of functional zones, combined with the efficient utilization of latent heat of phase change, the maximum temperature and stable temperature of the solid matrix are significantly reduced, the temperature oscillation amplitude is significantly reduced, and the overall cooling effect is better than that of the traditional single-layer plate structure, thus achieving a significant improvement in sweating cooling performance.

[0040] It should be noted that the porosity of all porous media in the bilayer porous media domain is not less than 0.7. The resulting technical effects include: providing low-resistance permeation channels and sufficient phase change space for the cooling medium, allowing liquid water to diffuse rapidly and uniformly throughout the entire porous media domain, and fully absorb heat and undergo vaporization phase change within the high specific surface area porous framework, thereby efficiently releasing the latent heat of phase change and enhancing heat transfer. Simultaneously, the high porosity ensures the synergistic effect of the upper and lower porous media layers in terms of functional zoning. The lower high-permeability medium can stably supply liquid to the upper layer without obstruction, while the upper high-heat-transfer-coefficient medium has sufficient pore volume to accommodate medium residence, vaporization, and gas film formation, ultimately achieving a significant reduction in wall temperature and effective suppression of temperature oscillations.

[0041] If the porosity is below 0.7, the flow resistance increases, hindering the penetration of the cooling medium and causing localized drying in the upper phase change region due to insufficient liquid supply. Simultaneously, the narrow pore channels restrict the vaporization and expansion space of the medium, preventing the full release of latent heat of phase change. Furthermore, excessively low porosity means a high proportion of solid skeleton, making it difficult for the gas film to continuously spread on the wall surface. High-temperature airflow directly impacts the wall, leading to a significant deterioration in cooling efficiency and failing to meet the thermal protection requirements under extreme high-temperature environments.

[0042] In a preferred embodiment of the structure, the two different types are: a combination of Gyroid-type porous media and granular porous media; or a combination of fibrous porous media and granular porous media; or a combination of fibrous porous media and Gyroid-type porous media.

[0043] In a preferred embodiment of the structure, the Gyroid-type porous medium is constructed using a triple-periodic minimal surface method and has a continuously interconnected periodic network pore structure.

[0044] Specifically, a schematic diagram of the microstructure of the Gyroid-type porous medium constructed by the TPMS (Triple Periodic Minimal Surface) method is shown below. Figure 1 The Gyroid-type porous medium is formed through topology optimization design, with an internal continuous and interconnected periodic network pore structure, pore diameter of 50-200 μm, and specific surface area of ​​600-900 m². 2 / m 3 It has a porosity of 0.8 and a compressive strength of ≥300MPa. Its core characteristics are excellent pore connectivity and good fluid distribution uniformity, enabling rapid penetration and uniform diffusion of cooling media, and meeting the requirements of media distribution and rapid flow.

[0045] In a preferred embodiment of the structure, the fibrous porous medium is a structure with interconnected pores formed by interwoven metal fibers or ceramic fibers.

[0046] Specifically, a schematic diagram of the microstructure of the fiber-type porous medium can be found in [reference needed]. Figure 2 Fiber-type porous media are formed by interweaving metal fibers (such as stainless steel fibers, nickel-based alloy fibers) or ceramic fibers (such as high-silica ceramic fibers, alumina fibers), with fiber diameters of 10-50 μm, pore diameters of 30-150 μm, and specific surface areas of 500-70 m². 2 / m 3 It has a porosity of 0.8 and an erosion resistance of ≥150MPa. Its core characteristic is strong stability in film formation, which can promote the smooth vaporization of liquid water and form a continuous and dense cooling film, thus meeting the requirements for film formation and stable heat exchange.

[0047] In a preferred embodiment of the structure, the particulate porous medium is a structure with interstitial pores formed by sintering metal particles or ceramic particles.

[0048] Specifically, a schematic diagram of the microstructure of the particulate porous medium can be found in [reference needed]. Figure 3 Particulate porous media are formed by sintering metal particles (e.g., copper particles, titanium alloy particles) or ceramic particles (e.g., alumina particles, silicon carbide particles). The particle size is 50-300 μm, the pore diameter is 20-100 μm, and the specific surface area is 700-1000 m². 2 / m 3 It has a porosity of 0.8 and a high temperature resistance of ≥2000℃. Its core characteristics are a large specific surface area and strong interfacial heat transfer capacity, which can promote the rapid vaporization phase change of liquid water and fully release latent heat, thus meeting the requirements for enhanced heat transfer and phase change activation.

[0049] In a preferred embodiment of the structure, the thicknesses of the first porous dielectric domain and the second porous dielectric domain are equal.

[0050] In this embodiment, the lower equal-thickness space ensures that the cooling medium can be fully preheated and evenly distributed to the high heat transfer coefficient region, while the upper equal-thickness space provides sufficient working distance for the efficient release of latent heat of phase change and the stable formation of continuous gas film. Thus, the complementary advantages of high permeability liquid supply and high heat transfer coefficient phase change are maximized through the synergy of the upper and lower layers, significantly reducing the wall temperature and suppressing temperature oscillation.

[0051] If the thickness of the first porous medium layer is greater than that of the second layer, it can easily lead to insufficient cooling medium supply in the upper region. The medium may completely vaporize before reaching the wall, causing localized drying and a rapid rise in wall temperature. If the thickness of the first porous medium layer is less than that of the second layer, liquid water may seep out of the wall before fully vaporizing and releasing its latent heat, resulting in low utilization of the latent heat of phase change and a decrease in overall cooling efficiency. Therefore, both unequal thickness scenarios disrupt the synergistic balance between the lower high-permeability medium ensuring liquid supply and the upper high-heat-transfer-coefficient medium enhancing phase change.

[0052] Preferably, the first porous medium domain and the second porous medium domain are fixedly connected by diffusion welding or high-temperature sintering process, and the porosity of the connection surface is not less than 90%.

[0053] In this embodiment, the structural continuity of the upper and lower porous media and the seamless connection of the fluid channels are achieved, enabling the cooling medium to flow smoothly across the interlayer interface with low resistance. If the permeability of the interlayer gaps is less than 90%, it can easily lead to a sharp increase in local flow resistance and uneven distribution of the cooling medium. The upper phase change region may experience localized drying and overheating due to insufficient supply. At the same time, the preheated medium in the lower layer cannot be delivered to the phase change region in time, resulting in a significant decrease in the utilization rate of the latent heat of phase change. Ultimately, this leads to an increase in wall temperature and aggravated temperature oscillations.

[0054] In a preferred embodiment of the structure, the fluid domain is provided with multiple guide walls to divide the fluid domain into multiple independent flow channels.

[0055] Preferably, multiple guide walls divide the fluid domain into multiple independent flow channels, making the flow rate of the cooling medium controllable before entering each part of the second porous medium domain, avoiding insufficient flow in local high heat flux areas leading to wall overheating and excessive flow in low heat flux areas leading to insufficient phase change.

[0056] In a preferred embodiment of the structure, the cooling medium is liquid water. After flowing through the fluid domain and being distributed, it enters the double-layer porous medium domain to permeate and sweat, and undergoes a vaporization phase change, thereby utilizing the latent heat of phase change to enhance heat transfer and cooling.

[0057] In a preferred embodiment of the structure, the structure is characterized in that it is used for thermal protection of high-temperature components on the surface of aerospace vehicles, the combustion chamber of an aero-engine, or the blades of a gas turbine.

[0058] In one embodiment, a schematic cross-sectional view of the multi-combination high-porosity phase change double-layer porous plate sweating cooling structure is shown below. Figure 4 It includes: a main flow region 1, a first layer of porous media 2, a second layer of porous media 3, a fluid region 4, a flow guide wall 5, and a coolant inlet 6.

[0059] Specifically, the mainstream region 1 serves as a channel for high-temperature airflow. A first porous medium layer 2 and a second porous medium layer 3 are stacked vertically to form a double-layer porous plate, with the first porous medium layer 2 located closer to the mainstream region 1 and the second porous medium layer 3 located further away from the mainstream region 1. The total thickness of the double-layer porous plate is 10cm, and the thickness ratio of the first porous medium layer 2 to the second porous medium layer 3 is 1:1, meaning each layer is 5cm thick. This 5cm thickness design provides ample space for the preheating and phase change process of the cooling medium while ensuring the structural mechanical strength, enabling it to withstand aerodynamic erosion and thermal stress impacts in scenarios such as spacecraft.

[0060] The fluid domain 4 is located below the second porous media domain 3, with a depth of 7-10 cm, and is adapted to the cross-sectional shape of the double-layer porous media domain (e.g., circular, rectangular, or irregular). The fluid domain 4 contains 4-8 guide walls 5, each 5-10 mm thick and spaced 5-10 cm apart. The guide walls 5 are integrally sintered with the fluid domain 4. The coolant inlet 6 is located at the bottom of the fluid domain 4 and is used to introduce liquid water cooling medium.

[0061] The first porous medium domain 2 and the second porous medium domain 3 are fixedly connected by welding or high-temperature sintering process, and the second porous medium domain 3 and the fluid domain 4 are also fixed by welding or high-temperature sintering process to ensure smooth flow of cooling medium without leakage.

[0062] The cooling medium enters the fluid domain 4 through the coolant inlet 6, and after being evenly distributed by the guide wall 5, it flows sequentially through the second porous media domain 3 and the first porous media domain 2. During the permeation process, the cooling medium absorbs heat and undergoes a vaporization phase change, utilizing the latent heat of the phase change to enhance the cooling of the porous media domains. Ultimately, a continuous cooling gas film is formed on the surface of the first porous media domain 2, isolating the high-temperature airflow in the main flow region 1 from direct heat exchange with the wall surface.

[0063] To better understand this disclosure, the following embodiments are provided to illustrate the technical effects of this disclosure.

[0064] All embodiments used the same boundary conditions in the simulation test: the cooling medium was liquid water at 25°C, the inlet flow velocity was 0.005 m / s, and the heat flux density was 1.5 × 10⁻⁶. 6 W / m 2The total thickness of the double-layer porous medium domain is 10 cm, with a layer thickness ratio of 1:1, and the porosity of each layer is 0.8.

[0065] Example 1: The upper layer is a Gyroid-type porous medium, and the lower layer is a particulate porous medium.

[0066] The specific parameters of the multi-combination high-porosity phase change double-layer porous plate sweating cooling structure in this embodiment are as follows:

[0067] The coolant inlet 6 is made of nickel-based alloy (Inconel 625), with a cross-sectional size of 10cm × 10cm. The interface is welded, and the weld has been inspected for defects such as pores and cracks. The fluid domain 4 is made of silicon carbide ceramic, with a depth of 10cm and a cross-sectional size of 10cm × 60cm. It has five guide walls 5 (10mm thick, spaced 10cm apart) inside. The guide walls are integrally sintered with the fluid domain. The flow channel has a rectangular cross-section and an inner wall roughness Ra≤1.8μm to ensure smooth flow of the cooling medium.

[0068] The first layer of Gyroid-type porous media uses a nickel-based alloy (Inconel 625) as the matrix and is formed by TPMS laser selective melting 3D printing. It has a pore diameter of 100 μm and a specific surface area of ​​750 m². 2 / m 3 The first layer has a compressive strength of 310 MPa and a pore connectivity of ≥96%. The second layer is a granular porous medium sintered from alumina ceramic particles with a particle size of 100 μm, a pore diameter of 50 μm, and a specific surface area of ​​850 m². 2 / m 3 The sintering temperature is 1550℃, and the pore connectivity is ≥96%. The cooling medium supply parameters include an inlet flow rate of 0.005m / s, a supply pressure of 0.3-0.5MPa, and a medium purity of ≥99.5% to avoid impurities clogging the pores.

[0069] The first porous media domain 2 and the second porous media domain 3 are fixed together by diffusion welding at a temperature of 1100℃, a holding time of 2.5h, and a welding pressure of 4MPa. The porosity of the joint surface is 95%, the joint strength is 250MPa, and the interface is tightly bonded with no risk of peeling. The second porous media domain 3 and the fluid domain 4 are fixed together by high-temperature sintering at a temperature of 1300℃ and a holding time of 3h. The joint gap is ≤0.1mm to ensure no leakage of cooling medium.

[0070] See Figure 5 and Figure 6Numerical simulation tests showed that the highest temperature of the solid matrix was 520K, the stable temperature was 490K, and the temperature fluctuation range was 10-15K. Compared with the single-layer fiber porous plate (highest temperature 605K, stable temperature 570K), the highest temperature decreased by nearly 90K and the stable temperature decreased by 80K, and the cooling performance was significantly better than that of the single-layer structure.

[0071] Example 2: The upper layer is a particulate porous medium, and the lower layer is a Gyroid-type porous medium.

[0072] The specific parameters of the multi-combination high-porosity phase change double-layer porous plate sweating cooling structure in this embodiment are as follows:

[0073] The parameters of the coolant inlet 6, fluid domain 4, and guide wall 5 are completely consistent with those of Example 1.

[0074] The first layer of granular porous media is formed by sintering alumina ceramic particles with a particle size of 100 μm, a pore diameter of 50 μm, and a specific surface area of ​​850 m². 2 / m 3 The sintering temperature is 1600℃, and the pore connectivity is ≥98%. The second layer, a Gyroid-type porous medium, uses silicon carbide ceramic as the matrix and is formed by TPMS photopolymerization 3D printing. It has a pore diameter of 150μm and a specific surface area of ​​650m². 2 / m 3 The compressive strength is 320 MPa, and the pore connectivity is ≥98%. The cooling medium supply parameters include an inlet flow velocity of 0.005 m / s, a supply pressure of 0.2-0.4 MPa, and a medium purity of ≥99.5%.

[0075] The first porous medium domain 2 and the second porous medium domain 3 are fixed together by a high-temperature sintering process. The sintering temperature is 1250℃, the holding time is 4.5h, and the sintering atmosphere is argon protection. The porosity of the connection surface is 92%, the connection strength is 220MPa, and there are no obvious interface defects. The second porous medium domain 3 and the fluid domain 4 are fixed together by the same process to ensure smooth flow of cooling medium without leakage.

[0076] See Figure 5 and Figure 6 Numerical simulation tests showed that the highest temperature of the solid matrix was 495K, the stable temperature was 475K, and the temperature fluctuation range was 10-20K. Compared with single-layer fiber porous plates, the highest temperature decreased by 110K, representing a temperature reduction of 18.3%.

[0077] Example 3: The upper layer is a fibrous porous medium, and the lower layer is a particulate porous medium.

[0078] The specific parameters of the multi-combination high-porosity phase change double-layer porous plate sweating cooling structure in this embodiment are as follows:

[0079] The parameters of the coolant inlet 6, fluid domain 4, and guide wall 5 are completely consistent with those of Example 1.

[0080] The first layer of fibrous porous media is formed by interwoven silicon carbide fibers with a fiber diameter of 20 μm, a pore diameter of 100 μm, and a specific surface area of ​​650 m². 2 / m 3 The first layer has an erosion resistance of 180 MPa, a fiber volume fraction of 20%, and a pore connectivity of ≥95%. The second layer is a granular porous medium sintered from silicon carbide particles with a particle size of 150 μm, a pore diameter of 40 μm, and a specific surface area of ​​900 m². 2 / m 3 The sintering temperature is 1450℃, and the porosity is ≥96%. The cooling medium supply parameters include an inlet flow rate of 0.005m / s, a supply pressure of 0.2-0.4MPa, and a medium purity of ≥99.5%.

[0081] The first porous media domain 2 and the second porous media domain 3 are fixed together by diffusion welding process. The welding temperature is 1050℃, the holding time is 3h, the welding pressure is 3MPa, the porosity of the joint surface is 93%, and the joint strength is 200MPa. The second porous media domain 3 and the fluid domain 4 are fixed together by welding. The weld is tested by penetrant testing and has no defects.

[0082] See Figure 5 and Figure 6 Numerical simulation tests showed that the highest temperature of the solid matrix was 520K, the stable temperature was 485K, and the temperature fluctuation range was 8-10K. Compared with the single-layer fiber porous plate, the highest temperature decreased by 80K, and the temperature drop was 13.3%.

[0083] Example 4: The upper layer is a particulate porous medium, and the lower layer is a fiber porous medium.

[0084] The specific parameters of the multi-combination high-porosity phase change double-layer porous plate sweating cooling structure in this embodiment are as follows:

[0085] The parameters of the coolant inlet 6, fluid domain 4, and guide wall 5 are completely consistent with those of Example 1.

[0086] The first layer of granular porous media is formed by sintering titanium alloy particles (Ti-6Al-4V), with a particle diameter of 120μm, a pore diameter of 60μm, and a specific surface area of ​​820m². 2 / m 3 The sintering temperature is 1200℃, and the pore connectivity is ≥96%. The second layer is a fibrous porous medium formed by interwoven 316L stainless steel fibers with a fiber diameter of 30μm, a pore diameter of 80μm, and a specific surface area of ​​680m². 2 / m 3The erosion resistance is 160 MPa, the fiber volume fraction is 20%, and the pore connectivity is ≥95%. The cooling medium supply parameters include an inlet flow velocity of 0.005 m / s, a supply pressure of 0.15-0.3 MPa, and a medium purity of ≥99.5%.

[0087] The first porous media domain 2 and the second porous media domain 3 are fixed together by diffusion welding process, with a welding temperature of 1050℃, a holding time of 3h, a welding pressure of 5MPa, a pore penetration rate of 93% at the joint surface, and a joint strength of 240MPa; the second porous media domain 3 and the fluid domain 4 are fixed together by the same process to ensure the structural airtightness.

[0088] See Figure 5 and Figure 6 Numerical simulation tests showed that the highest temperature of the solid matrix was 500K, the stable temperature was 480K, and the temperature fluctuation range was 10-15K. Compared with the single-layer fiber porous plate, the highest temperature decreased by 105K, and the temperature drop was 17.5%.

[0089] Example 5: The upper layer is a fiber-type porous medium, and the lower layer is a Gyroid-type porous medium.

[0090] The specific parameters of the multi-combination high-porosity phase change double-layer porous plate sweating cooling structure in this embodiment are as follows:

[0091] The parameters of the coolant inlet 6, fluid domain 4, and guide wall 5 are completely consistent with those of Example 1.

[0092] The first layer of fibrous porous media is formed by interweaving 316L stainless steel fibers with a fiber diameter of 30μm, a pore diameter of 80μm, and a specific surface area of ​​680m². 2 / m 3 The first layer has an erosion resistance of 150 MPa, a fiber volume fraction of 20%, and a pore connectivity of ≥95%. The second layer, a Gyroid-type porous medium, uses 304 stainless steel as the matrix and is formed by TPMS laser selective melting 3D printing, with a pore diameter of 150 μm and a specific surface area of ​​650 m². 2 / m 3 It has a compressive strength of 280 MPa and a pore connectivity of 96%. The cooling medium supply parameters include an inlet flow velocity of 0.005 m / s, a supply pressure of 0.1-0.3 MPa, and a medium purity of ≥99.5%.

[0093] The first porous media domain 2 and the second porous media domain 3 are fixed by bolts and sealed with high-temperature resistant sealant. The bolts are made of 304 stainless steel and the sealant is ≥800℃. The second porous media domain 3 and the fluid domain 4 are fixed by welding, with no risk of leakage.

[0094] See Figure 5 and Figure 6Numerical simulation tests showed that the highest temperature of the solid matrix was 505K, the stable temperature was 470K, and the temperature fluctuation range was 8-10K. Compared with the single-layer fiber porous plate, the highest temperature decreased by 100K, and the temperature drop was 16.7%.

[0095] Example 6: The upper layer is a Gyroid-type porous medium, and the lower layer is a fiber-type porous medium.

[0096] The specific parameters of the multi-combination high-porosity phase change double-layer porous plate sweating cooling structure in this embodiment are as follows:

[0097] The parameters of the coolant inlet 6, fluid domain 4, and guide wall 5 are completely consistent with those of Example 1.

[0098] The first layer of Gyroid-type porous media uses 304 stainless steel as the substrate and is formed by TPMS laser selective melting 3D printing. It has a pore diameter of 120μm and a specific surface area of ​​700m². 2 / m 3 The first layer has a compressive strength of 300 MPa and a pore connectivity of ≥97%. The second layer is a fibrous porous medium formed by interwoven alumina-silica ceramic fibers with a fiber diameter of 25 μm, a pore diameter of 100 μm, and a specific surface area of ​​650 m². 2 / m 3 The erosion resistance is 150 MPa, the fiber volume fraction is 20%, and the pore connectivity is ≥95%. The cooling medium supply parameters include an inlet flow velocity of 0.005 m / s, a supply pressure of 0.1-0.25 MPa, and a medium purity of ≥99.5%.

[0099] The first porous media domain 2 and the second porous media domain 3 are fixed together by diffusion welding process, with a welding temperature of 1000℃ and a holding time of 3h. The porosity of the joint surface is 91% and the joint strength is 180MPa. The second porous media domain 3 and the fluid domain 4 are fixed together by bolts and sealed with high-temperature resistant sealant, which facilitates later maintenance.

[0100] See Figure 5 and Figure 6 Numerical simulation tests showed that the highest temperature of the solid matrix was 530K, the stable temperature was 510K, and the temperature fluctuation range was 11-16K. Compared with single-layer fiber porous plates, the highest temperature decreased by 75K, a cooling rate of 12.5%.

[0101] In summary, when the upper porous medium domain of the multi-combination high-porosity phase change double-layer porous plate sweating cooling structure is selected as particulate porous medium and the lower porous medium domain is selected as Gyroid porous medium, the cooling effect is optimal in the above embodiments, and the cooling effect is better than that of the traditional single-layer plate structure, thus achieving a significant improvement in sweating cooling performance.

[0102] Although the embodiments of this disclosure have been described above in conjunction with the accompanying drawings, this disclosure is not limited to the specific embodiments and application fields described above. The specific embodiments described above are merely illustrative and instructive, and not restrictive. Those skilled in the art can make many other forms based on the teachings of this specification and without departing from the scope of protection of the claims of this disclosure, and all of these are within the scope of protection of this disclosure.

Claims

1. A multi-combination high-porosity phase change double-layer porous plate sweating and cooling structure, characterized in that, include: The fluid domain contains a flow guiding structure for distributing the cooling medium. A double-layer porous medium domain disposed above the fluid domain is used to receive cooling medium from the fluid domain. The double-layer porous medium domain is composed of a first layer porous medium domain and a second layer porous medium domain. The first porous medium domain and the second porous medium domain are selected from any two different types of porous media, namely Gyroid type porous media, fiber type porous media and particle type porous media, and the porosity of all porous media in the dual-layer porous medium domain is not less than 0.

7.

2. The structure according to claim 1, characterized in that, Preferably, the two different types are: a combination of Gyroid-type porous media and granular porous media; or a combination of fiber-type porous media and granular porous media; or a combination of fiber-type porous media and Gyroid-type porous media.

3. The structure according to claim 1, characterized in that, The Gyroid-type porous medium is constructed using the triple periodic minimal surface method and has a continuously interconnected periodic network pore structure.

4. The structure according to claim 1, characterized in that, The fibrous porous medium is a structure with interconnected pores formed by interwoven metal or ceramic fibers.

5. The structure according to claim 1, characterized in that, The granular porous medium is a structure with gaps and pores formed by sintering metal particles or ceramic particles.

6. The structure according to claim 1, characterized in that, The thicknesses of the first porous medium domain and the second porous medium domain are equal.

7. The structure according to claim 1, characterized in that, The first porous medium domain and the second porous medium domain are fixedly connected by diffusion welding or high-temperature sintering process, and the porosity of the connection surface is not less than 90%.

8. The structure according to claim 1, characterized in that, The flow guiding structure inside the fluid domain is a flow guiding wall, which is used to divide the fluid domain into multiple independent flow channels.

9. The structure according to claim 1, characterized in that, The cooling medium is liquid water. After flowing through the fluid domain and being distributed, it enters the double-layer porous medium domain to permeate and sweat, and undergoes vaporization phase change, so as to enhance heat transfer and cooling by utilizing the latent heat of phase change.

10. The cooling structure according to any one of claims 1-9, characterized in that, The structure is used for thermal protection of high-temperature components on the surface of aerospace vehicles, the combustion chamber of aircraft engines, or the blades of gas turbines.

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