A directional porous structure sweating cooling system and its manufacturing method

Abstract

This invention discloses a directional porous structure sweating cooling system and its manufacturing method. The directional porous structure in the system consists of several channels with spaced pores. One end of each pore is connected to a coolant tank, and the other end forms an ablation interface layer. Coolant is contained in the coolant tank and flows through the pores of the directional porous structure. The ablation interface layer seals the pores, preventing coolant overflow. By using the directional porous structure, coolant flows from the coolant tank through the pores to specific areas, providing directional cooling to localized overheating areas and solving the problem of localized overheating, thus improving the reliability of the sweating cooling system. Furthermore, by using the ablation interface layer, the coolant is sealed under low heat flux conditions, and under high heat flux conditions, the ablation interface layer erodes to create pores that guide the coolant out, achieving a synergistic effect of active sweating cooling and passive ablation cooling, and realizing efficient utilization of the coolant.

Description

Technical Field

[0001] This invention belongs to the field of aerospace thermal protection technology, and relates to a directional porous structure sweating cooling system and its manufacturing method. Background Technology

[0002] When an aircraft flies at high speed, its stagnation area, wing leading edge, and engine interior are subjected to severe extreme thermal loads. The higher the aircraft's speed, the more severe the heating of hot-end components. Sweating cooling, as one of the most efficient active thermal protection technologies, has the advantages of shape and reusability, and holds significant development potential in the field of aircraft thermal protection. Traditional sweating cooling structures have a relatively uniform pore distribution, and these pores are interconnected in all directions. Therefore, the coolant flow direction within the porous structure is random and difficult to effectively constrain and control. In actual service environments, the thermal load on the aircraft surface is uneven. Under high heat flux conditions, porous structures are prone to localized overheating areas, increasing coolant flow resistance. In traditional uniform sweating cooling porous structures, the coolant is forced to flow to areas with lower resistance, resulting in ineffective cooling of overheated areas and subsequent ablation damage, severely affecting the reliability of sweating cooling thermal protection technology. Summary of the Invention

[0003] The purpose of this invention is to solve the problem in the prior art where, when the heat load on the surface of an aircraft is uneven, the coolant flows to other areas with less resistance, resulting in the overheated areas not being effectively cooled and thus causing ablation damage. The invention provides a directional porous structure sweating cooling system and its manufacturing method.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A directional porous structure sweating cooling system includes a directional porous structure, an ablation interface layer, and a coolant tank;

[0006] The directional porous structure is formed by several channels with spaced pores. One end of each pore is connected to a coolant tank, and the other end is an ablation interface layer. The coolant tank contains coolant, which flows through the pores of the directional porous structure. The ablation interface layer seals the pores of the directional porous structure to prevent coolant from overflowing.

[0007] A further improvement of the present invention is that:

[0008] The directional porous structure uses a metal-based or ceramic-based composite material as the matrix.

[0009] The coolant storage tank adopts a partitioned box structure, including several boxes, and the boxes are arranged in a corresponding manner with the openings.

[0010] Several interconnected micropores are provided on the channel wall between adjacent pores.

[0011] The ablation interface layer is composed of organic polymers.

[0012] A method for manufacturing a directional porous structure sweating cooling system includes the following steps:

[0013] Plant stem tissues were optimized and screened to select those with uniformly distributed directional microchannels;

[0014] Physical / chemical pretreatment of the selected plant stem tissues;

[0015] The plant stem tissue is dried and then pyrolyzed and carbonized to form a directional porous carbon structure.

[0016] The directional porous carbon structure is impregnated and in-situ ceramicized, while retaining the microstructural features of the directional porous carbon structure.

[0017] By controlling process parameters, a directional porous structure with directional pore channels can be obtained;

[0018] By controlling the parameters of organic polymer-based materials, an ablation interface layer is constructed on the surface of a directional porous structure.

[0019] The directional porous structure is connected and installed to the coolant tank.

[0020] The impregnation of the oriented porous carbon structure is carried out using silica sol or melt infiltration processes.

[0021] The process parameters include the sol or silica ratio, impregnation pressure, number of impregnations, sintering environment parameters, and plant stem tissue structure parameters after pyrolysis and carbonization.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] This invention provides a directional porous structure sweating cooling system. By setting a directional porous structure, the coolant flows from the coolant tank through the pores to a specific area, providing directional cooling to the localized overheating areas that occur in the porous structure under non-uniform heat flow conditions. This solves the problem of localized overheating in the sweating cooling structure under non-uniform heat flow conditions, achieves efficient utilization of the coolant, and improves the reliability of the sweating cooling system. Furthermore, by setting an ablation interface layer, the coolant is sealed under low heat flow conditions, and under high heat flow conditions, the ablation interface layer is ablated to form pores that guide the coolant out, achieving adaptive cooling. This realizes the synergistic effect of active sweating cooling and passive ablation cooling, and achieves efficient utilization of the coolant.

[0024] Furthermore, by setting interconnecting micropores on the channel walls, the flow resistance of the coolant inside the porous structure is greatly reduced, the coolant driving pressure requirement is lowered, and the pressure inside the sweating cooling porous structure is decreased. The reliability of the sweating cooling porous structure is further improved by adjusting the size and distribution of the interconnecting micropores between adjacent directional pore channels.

[0025] Furthermore, by using ceramic matrix composites to create oriented porous structures, higher high-temperature resistance and oxidation resistance can be provided, while reducing the mass of the porous structure, thereby achieving efficient utilization of coolant and lightweighting of the cooling system. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the directional porous structure sweating cooling system before heat flow in this invention;

[0028] Figure 2 This is a schematic diagram of the directional porous structure sweating cooling system under heat flow in this invention;

[0029] Figure 3 A comparison of coolant flow rates between directional porous structures and traditional uniform porous structures at the same external temperature.

[0030] Figure 4 This is a comparison of the surface temperature of the directional porous structure and the traditional uniform porous structure in a sweating cooling system when the porosity at the blockage is 0.05.

[0031] Wherein: 1-coolant, 2-channel wall, 3-connecting micropores, 4-ablation interface layer, 5-directional pore channel, 6-high temperature heat flow, 7-coolant tank, 8-porous structure local overheating area. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0035] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0037] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0038] The present invention will now be described in further detail with reference to the accompanying drawings:

[0039] See Figure 1The diagram shows the principle of the directional porous structure sweating cooling system of the present invention, which includes a directional porous structure, an ablation interface layer 4, and a coolant tank 7. The directional porous structure forms a plurality of pores through a plurality of channel walls 2. The directional porous structure uses a high-temperature resistant and oxidation-resistant metal-based or ceramic-based composite material as the matrix. When the directional porous structure uses a ceramic-based composite material, it can further provide higher high-temperature resistance and oxidation resistance, while reducing the weight of the porous structure, thereby achieving the purpose of efficient utilization of coolant and lightweight cooling system. Several interconnected micropores 3 are provided on the channel wall 2 between adjacent pores. One end of the pore is connected to the coolant tank 7, and the other end is an ablation interface layer 4. The ablation interface layer is composed of organic polymers with fewer high-temperature ablation solid products. The coolant tank 7 adopts a partitioned box, which can apply different driving forces to the coolant in different small boxes. The coolant tank 7 is filled with coolant, and the coolant pressure is provided by a pressure pump. Different pressures are applied at different positions in the coolant tank 7 to make the coolant flow in the pores of the directional porous structure. The ablation interface layer 4 seals the pores of the directional porous structure to prevent the coolant from overflowing.

[0040] See Figure 2 This diagram illustrates the directional porous structure sweating cooling system of the present invention under heat flow conditions. The size of the coolant arrows in the diagram represents the flow rate, and the size of the high-temperature heat flow arrows represents the heat flow density. In the directional porous structure sweating cooling system, the ablation interface thin layer 4 is used to seal the coolant inside the porous structure, preventing overflow and waste before heat flow or under low heat flow conditions. Simultaneously, the thin layer prevents delayed cooling under high heat flow conditions or blockage of pore channels by solid products after ablation, thus preventing ablation failure. Under extremely uneven external heat loads, the ablation interface layer first undergoes pyrolysis and ablation under high heat flow conditions, creating pores that guide the coolant out, achieving a synergistic cooling effect of active sweating cooling and passive ablation. Due to the low flow resistance of the coolant in the directional porous structure, an ablation interface thin layer needs to be constructed on the outer surface of the porous structure. This seals the coolant under low heat flow conditions, and under high heat flow conditions, the ablation interface layer ablates to create pores that guide the coolant out, achieving adaptive cooling. This realizes the synergistic effect of active sweating cooling and passive ablation cooling, and achieves efficient utilization of the coolant.

[0041] The directional porous channel 5 is mainly used to constrain and control the directional flow of coolant 1, achieving directional regulation of the coolant. The directional porous channel reduces the flow resistance of the coolant and improves the driving pressure transmission efficiency, thereby enabling the application of higher and faster driving pressure to the coolant within the channel, improving the timeliness of the cooling system. Advanced processes can be used to achieve interconnection and regulation between adjacent channels within the directional porous channel, controlling the size and distribution of the connecting micropores 3 between adjacent porous channels. This allows for appropriate adjustment of the internal pressure and flow rate of adjacent channels without significantly affecting the coolant flow direction. In cases of uneven distribution of external high-temperature heat flow 6, the coolant flow rate can be increased by regulating the flow through the small tank in the coolant storage tank 7, directing it towards the locally overheated area 8 of the porous structure, achieving directional cooling of the overheated area. This invention can significantly improve the problem of localized overheating caused by uneven heat flow distribution during the sweating cooling process, achieving controllable adjustment of the coolant flow direction and flow rate, and effectively improving the cooling effect and reliability of the cooling system.

[0042] One embodiment of the present invention proposes a method for manufacturing a directional porous structure sweating cooling system, specifically including:

[0043] First, based on meeting the requirements for coolant use in directional porous structure regulation under service thermal conditions, plant stem tissues were optimized and screened to select tissues with uniformly distributed directional microchannels. Then, the selected plant stem tissues underwent physical / chemical pretreatment to obtain microstructures that are easy to design and regulate later. Subsequently, the plant stem tissues were dried in a high-temperature atmosphere and pyrolyzed to form a directional porous carbon structure. Then, the porous carbon structure was impregnated using silica sol or melt silica infiltration processes, followed by in-situ ceramization in a high-temperature atmosphere, while preserving the microstructural characteristics of the porous carbon structure. By controlling the sol or silica infiltration ratio, impregnation pressure, number of impregnations, sintering environment, and structural parameters of the pyrolyzed and carbonized plant stem tissue, a porous structure with directional pore channels was obtained. Then, using an organic polymer with fewer solid products from high-temperature ablation, a thin ablation interface layer was constructed on the surface of the directional porous structure by controlling the thermophysical, mechanical, and thickness parameters of the organic polymer-based material. Finally, the directional porous structure is connected and installed with the coolant tank. The coolant pressure can be independently adjusted through the partitioned small boxes in the tank. The number, size, and form of the small boxes in the tank can be adjusted according to the size and shape of the directional porous structure, thus realizing the design of the directional porous structure sweating cooling system.

[0044] The directional porous structure sweating cooling system of the present invention is based on the characteristic of the directional pore channels in the microstructure of plant stem tissue. Through a special design and preparation process, the plant stem tissue is transformed into a high-temperature resistant and oxidation-resistant ceramic matrix composite material, such as silicon carbide matrix composite material, while retaining the directional pore channel microstructure characteristics of the stem tissue. After optimization, it is applied to the sweating cooling thermal protection system.

[0045] See Figures 3-4 The figure shows a parameter comparison between directional porous structures and traditional uniform porous structures. To achieve the same cooling effect, the directional porous structure consumes significantly less coolant than the traditional uniform porous sweating cooling structure, significantly improving cooling efficiency and enabling a lighter sweating cooling system. When partial blockage occurs in the porous structure, the directional porous structure, compared to the traditional uniform structure, can achieve stable coolant control in the blocked area, further improving the reliability of the sweating cooling system.

[0046] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A directional porous structure sweating cooling system, characterized in that, It includes a directional porous structure, an ablation interface layer (4), and a coolant tank (7); The directional porous structure is formed by several channel walls (2) with several pores at intervals. One end of the pores is connected to the coolant tank (7), and the other end is an ablation interface layer (4). The coolant tank (7) is filled with coolant, which flows in the pores of the directional porous structure. The ablation interface layer (4) seals the pores of the directional porous structure to prevent coolant from overflowing.

2. The directional porous structure sweating cooling system as described in claim 1, characterized in that, The directional porous structure uses a metal-based or ceramic-based composite material as the matrix.

3. The directional porous structure sweating cooling system as described in claim 1, characterized in that, The coolant storage tank (7) adopts a partitioned box structure, including several boxes, and the boxes are arranged in a corresponding manner with the openings.

4. The directional porous structure sweating cooling system as described in claim 1, characterized in that, A plurality of interconnecting micropores (3) are provided on the channel wall (2) between adjacent pores.

5. The directional porous structure sweating cooling system as described in claim 1, characterized in that, The ablation interface layer (4) is composed of organic polymers.

6. A method for manufacturing a directional porous structure sweating cooling system, characterized in that, Includes the following steps: Plant stem tissues were optimized and screened to select those with uniformly distributed directional microchannels; Physical / chemical pretreatment of the selected plant stem tissues; The plant stem tissue is dried and then pyrolyzed and carbonized to form a directional porous carbon structure. The directional porous carbon structure is impregnated and in-situ ceramicized, while retaining the microstructural features of the directional porous carbon structure. By controlling process parameters, a directional porous structure with directional pore channels can be obtained; By controlling the parameters of organic polymer-based materials, an ablation interface layer is constructed on the surface of a directional porous structure. The directional porous structure is connected and installed to the coolant tank.

7. The manufacturing method of a directional porous structure sweating cooling system as described in claim 6, characterized in that, The impregnation of the oriented porous carbon structure is carried out using silica sol or melt infiltration processes.

8. The manufacturing method of a directional porous structure sweating cooling system as described in claim 6, characterized in that, The process parameters include the sol or silica ratio, impregnation pressure, number of impregnations, sintering environment parameters, and plant stem tissue structure parameters after pyrolysis and carbonization.

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