A porous network transpiration cooling thermal protection device

Abstract

The present invention discloses a porous network transpiration cooling thermal protection device, comprising a transpiration cooler and a pressurized delivery network. The transpiration cooler comprises a porous layer, a metal layer, and a liquid separation layer. Discrete microgrooves connecting the porous layer and the liquid separation layer are provided on the metal layer. The liquid separation layer is connected to the pressurized delivery network. The transpiration cooler is divided into at least two heat flow regions according to different heat flow levels. The pores of the porous layer are distributed in a stepped manner according to the different heat flow regions of the transpiration cooler. The liquid separation layer is provided with a liquid separation cavity corresponding to each heat flow region. The pressurized delivery pipe reduces the supply of cooling medium to each liquid separation cavity as the heat flow level of the corresponding heat flow region decreases. The transpiration cooler ensures precise delivery of cooling medium to the aircraft nose cone through the stepped design of the number and depth of the discrete microgrooves in the metal layer, the stepped design of the pores in the porous layer, and the segmented pressurization design of the liquid separation cavity, thereby achieving uniform temperature cooling of the aircraft nose cone.

Description

Technical Field

[0001] The invention relates to the technical field of thermal protection, in particular to a porous network sweating cooling thermal protection device. Background Art

[0002] Long-endurance, high-speed transport systems are a major development need in my country. However, aircraft face unique thermal protection challenges, including extreme aerodynamic heating fluxes, significant surface temperature gradients, and limited cooling resources. The challenges are particularly severe in the nose cone. Therefore, a reusable, efficient thermal protection system is urgently needed to ensure safe and efficient flight.

[0003] Conventional thermal protection technology has low cooling efficiency and cannot meet the thermal protection needs of long-endurance, high-speed transportation systems. Phase change sweating cooling technology has strong cooling capacity and high cooling efficiency, and has become an important development direction of the new generation of long-endurance aircraft nose cone thermal protection technology.

[0004] Traditional phase-change transpiration cooling thermal protection systems, based on porous media transpiration structures and a coolant supply network, are subject to increased high-temperature heat flux on the nose cone and other tip areas due to shock wave interference and curved surface effects. This leads to uneven heat load distribution and significant temperature gradients on the nose cone surface. Uneven load distribution on the nose cone also results in high resistance to the coolant supply, leading to insufficient coolant supply and deteriorated heat transfer, posing a serious safety hazard to the aircraft. During long-endurance flight, fluctuations in ambient temperature and pressure, as well as internal coolant delivery pressure and temperature, can affect the control of the coolant flow rate in the transpiration cooling system. Therefore, a thermal protection device and self-interference control method are urgently needed that can achieve precise coolant supply and ensure efficient and uniform cooling of the nose cone. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to propose a porous network sweat cooling thermal protection device that realizes uniform temperature cooling.

[0006] In order to achieve the purpose of the present invention, the technical solution adopted is:

[0007] A porous network transpiring cooling thermal protection device comprises a transpiring cooler and a pressurized delivery network, wherein the transpiring cooler comprises a porous layer, a metal layer and a liquid separation layer, wherein discrete microgrooves connecting the porous layer and the liquid separation layer are provided on the metal layer, and the liquid separation layer is connected to the pressurized delivery network, and the transpiring cooler is divided into at least two heat flow areas according to different heat flow levels; the pores of the porous layer are distributed in a stepped manner according to the different heat flow areas of the transpiring cooler; a liquid separation cavity corresponding to each of the heat flow areas is provided in the liquid separation layer, and the pressurized delivery pipe reduces the supply of cooling medium in each liquid separation cavity as the heat flow level of the corresponding heat flow area decreases.

[0008] Preferably, the porous layer is composed of regular vertical flow channels and through flow channels. The coupling design of the vertical flow channels and the through flow channels enhances the infiltration flow of the cooling medium in the complex network of the porous layer, thereby achieving the purpose of reducing the temperature gradient of the porous layer and reducing the consumption of the cooling medium.

[0009] Preferably, in different heat flow areas, the pore diameters of the through flow channels are the same to ensure sufficient penetration and flow of the cooling medium.

[0010] Preferably, the pores of the vertical flow channels are distributed in a stepped manner, with large-pore network flow channels configured in high heat flow areas, medium-pore network flow channels configured in medium heat flow areas, and low-pore network flow channels configured in low heat flow areas. The cooling medium supplied by the transpiring cooler in the high, medium and low heat flow areas is reduced in a stepped manner, thereby achieving efficient uniform temperature cooling of the aircraft nose cone.

[0011] Preferably, the number of discrete microgrooves in the metal layer is distributed in a stepped manner to match the cooling medium drainage requirements. More discrete microgrooves in the metal layer are arranged in high heat flux areas to improve the cooling medium drainage capacity, while fewer discrete microgrooves in the metal layer are arranged in low heat flux areas to weaken the cooling medium drainage capacity, thereby enhancing the segmented and precise supply of the cooling medium.

[0012] Preferably, the discrete microgrooves are also distributed in a stepped manner in depth, and the high heat flux area near the stagnation point is almost penetrated by the discrete microgrooves to reduce the flow resistance of the cooling medium in the porous layer, increase the cooling medium supply to the porous layer in the high heat flux area, and achieve the purpose of eliminating local hot spots. For the low heat flux area, the discrete microgrooves do not penetrate the porous layer.

[0013] Preferably, the porous layer and the metal layer are both manufactured by 3D printing micro-machining metal integrated additive manufacturing. The 3D printing micro-machining technology is based on the selective laser sintering method and utilizes an EOS290 metal 3D printer (including but not limited to this printer) to realize the manufacture of the porous layer and the metal layer with a three-dimensional pore structure by layer-by-layer powder laying and sintering.

[0014] Preferably, the additive manufacturing material is a high temperature resistant and corrosion resistant nickel-based alloy (including but not limited to nickel-based alloy).

[0015] Preferably, the transpiration cooler liquid separation chamber adopts a segmented pressurization design to achieve corresponding matching with high, medium and low heat flow areas, allowing active regulation of the supply pressure of the cooling medium to achieve segmented and precise supply of the cooling medium.

[0016] Preferably, the boost delivery network consists of a boost air chamber, a liquid storage chamber, a pipeline, a boost piston, and a regulating valve. The boost piston divides the entire cavity into a boost air chamber and a liquid storage chamber. The movement of the boost piston will cause the volume of the boost air chamber and the liquid storage chamber to change accordingly, and at the same time drive the cooling medium in the liquid storage chamber to be injected into the liquid separation chamber through the pipeline, thereby realizing the supply of cooling medium.

[0017] Preferably, the boost piston and the entire cavity are made of high-temperature resistant low-thermal conductivity materials to ensure the electrical heating expansion effect of the inert gas in the boost air cavity, thereby reducing heat leakage of the boost air cavity.

[0018] Preferably, the first-order anti-disturbance control method of the boost delivery network uses the arithmetic average measurement value of the temperature of each area of the sweat cooler as a feedback signal, and achieves the purpose of supplying the cooling medium flow to each liquid chamber by adjusting the opening of the regulating valve.

[0019] Preferably, the first-order active disturbance rejection control method uses an extended state observer (ESO) to estimate and compensate for disturbances such as external ambient temperature and pressure fluctuations and internal cooling fluid delivery pressure and temperature during long-duration flight of the aircraft in real time, thereby improving the robustness of the pressurized delivery and sweating cooling thermal protection device.

[0020] Preferably, the extended state observer is as shown in formula (1):

[0021]

[0022] z1 is the estimated value of the control system output value y, which represents the average temperature of each heat flow area; z2 is the estimated value of the total disturbance; is the derivative of z1; is the derivative of z2; b0 is b n Estimates, P n is the object open-loop gain, T n is the time constant; u is the control variable, representing the opening signal of each regulating valve; L1 and L2 are observer parameters. L = [L1 L2] is the observer parameter, and the values of L1 and L2 are obtained by adjusting the formula (2):

[0023]

[0024] In formula (2), ω0 is the bandwidth of the extended state observer.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) According to different heat flow areas, the number and depth of discrete microgrooves in the metal layer are stepped to design the porous layer pore step design and the liquid chamber segmented pressurization design to ensure the precise delivery of the cooling medium of the sweat cooler, so as to achieve uniform temperature cooling of the entire sweat cooling thermal protection device;

[0027] (2) By introducing an electrically heated pressurized delivery pipeline network, the existing problems of high-pressure gas cylinder pressurization, such as the additional heavy load and the difficulty in ensuring reliability in the pump-driven pressurization space, are overcome, significantly reducing the aircraft load.

[0028] (3) By introducing the self-anti-disturbance control method of the liquid chamber flow, the unpredictable disturbances in the supplementary control process are predicted in real time, further ensuring the precise zoning delivery of the cooling medium of the sweat cooler, and finally realizing the control of the temperature of each area of the sweat cooler. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of the porous network sweating cooling device of the present invention;

[0030] Figure 2 The distribution diagram of high, medium and low heat flux areas of the nose cone of the aircraft of the present invention;

[0031] Figure 3 This is a partial enlarged view of the stepped pore porous layer of the present invention;

[0032] Figure 4 This is a schematic diagram of the principle of the porous network sweating cooling device of the present invention;

[0033] Figure 5 This is a first-order active disturbance rejection control structure diagram of the sweating cooling thermal protection device of the present invention;

[0034] Description of the numbers in the figure:

[0035] 1. Liquid separation chamber; 101. Liquid separation chamber 1; 102. Liquid separation chamber 2; 103. Liquid separation chamber 3; 2. Discrete microgrooves; 3. Metal layer; 4. Porous layer; 401. Macropore porous layer; 402. Medium-pore porous layer; 403. Small-pore porous layer; 5. Pipeline; 6. Control valve; 601. Control valve 1; 602. Control valve 2; 603. Control valve 3; 7. Liquid storage chamber; 8. Booster piston; 9. Electric heating wire; 10. Booster air chamber; 11. Through flow channel; 12. Cooling fluid; 13. Vertical flow channel; 14. Cooling fluid steam; 15. High-temperature and high-speed airflow; 16. High heat flow region; 17. Medium heat flow region; 18. Low heat flow region. DETAILED DESCRIPTION

[0036] The following describes in detail embodiments of the present invention, which are illustrated in the accompanying drawings. The same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0037] This embodiment provides a porous network transpiring cooling heat protection device, which includes a transpiring cooler and a pressurized transmission pipe network. Figure 1 As shown, the transpiring cooler comprises a porous layer 4, a metal layer 3 and a liquid separation chamber 1, which is connected to the pressurized delivery network through the cooling medium inlet pipe of the liquid separation chamber 1. The metal layer 3 is attached to the inside of the porous layer 4, and the porous layer 4 and the liquid separation chamber 1 are connected through discrete microgrooves 2. Figure 2 As shown, according to the interaction between the high-temperature and high-speed airflow 15 and the aircraft nose cone, the transudation cooler is divided into a high heat flow area 16, a medium heat flow area 17 and a low heat flow area 18; according to the different heat flow areas of the transudation cooler, the pores of the porous layer 4 are distributed in a stepped manner, the discrete microgrooves 2 are distributed in a stepped manner in number and depth, and the liquid separation chamber 1 is designed with segmented pressurization to ensure the precise delivery of the cooling medium 12 of the transudation cooler.

[0038] like Figure 3As shown, the porous layer 4 is composed of regular vertical flow channels 13 and through flow channels 11. The vertical flow channels 13 have a circular cross-section (can also be square, triangular, etc.), and the spacing between each flow channel is 0.3mm (the spacing between such flow channels includes but is not limited to 0.3mm). The through flow channels 11 have a circular cross-section (can also be square, triangular, etc.), and the spacing between each flow channel is 0.3mm (the spacing between such flow channels includes but is not limited to 0.3mm). The coupled design of the vertical flow channels 13 and the through flow channels 11 enhances the permeation flow of the cooling medium 12 within the complex network of the porous layer 4, improving the sweat cooling efficiency, effectively reducing the temperature gradient of the porous layer 4, and achieving the purpose of reducing the consumption of the cooling medium 12. In different heat flow regions, the through-flow channel 11 has the same pore diameter of 0.4mm (this pore diameter includes but is not limited to 0.4mm); the vertical flow channel 13 has a stepped pore distribution. In the high heat flow region, a large-pore network flow channel 401 is configured, and the pore diameter of the large-pore network flow channel 401 is A (A includes but is not limited to 0.6mm); in the medium heat flow region, a medium-pore network flow channel 402 is configured, and the pore diameter of the medium-pore network flow channel 402 is B (B includes but is not limited to 0.5mm); in the low heat flow region, a low-pore network flow channel 403 is configured, and the pore diameter of the low-pore network flow channel 403 is C (C includes but is not limited to 0.4mm, ensuring that A>B>C). The cooling medium 12 supplied by the transpiring cooler in the high, medium, and low heat flow regions decreases in a stepped manner, achieving efficient and uniform temperature cooling of the aircraft nose cone.

[0039] The metal layer 3 is attached to the interior of the porous layer 4, and the porous layer 4 and the liquid separation chamber 1 are connected by discrete microgrooves 2 arranged in the metal layer 3. The discrete microgrooves 2 arranged in the metal layer 3 are arranged in a stepped distribution. More discrete microgrooves 2 are arranged in high heat flux areas to improve the cooling medium 12 drainage capacity, providing a large amount of cooling medium 12 to these high heat flux areas; fewer discrete microgrooves 2 are arranged in low heat flux areas to weaken the cooling medium 12 drainage capacity, providing a small amount of cooling medium 12 to these low heat flux areas, thereby enhancing the precise supply of cooling medium 12. The cross-section of the discrete microgrooves 2 is circular (can also be square, triangular, etc.), the microgroove diameter is 2 mm (the microgroove diameter includes but is not limited to 2 mm), and the discrete microgrooves 2 are also distributed in a stepped manner in depth. The high heat flux area near the stagnation point is almost penetrated by the discrete microgrooves 2 to reduce the flow resistance of the cooling medium 12 in the porous layer 4, increase the supply of the cooling medium 12 in the porous layer 4 in the high heat flux area, and achieve the purpose of eliminating local hot spots. For the low heat flux area, the discrete microgrooves 2 do not penetrate the porous layer 4.

[0040] Both the porous layer 4 and the metal layer 3 are manufactured using 3D printing and micromachining technology. This 3D printing micromachining technology is based on the selective laser melting (SLM) method, utilizing an EOS290 metal 3D printer (including but not limited to this printer) to achieve the three-dimensional porous structure of the porous layer 4 and the metal layer 3 through layer-by-layer powder laying and sintering. In the present invention, the nickel-chromium alloy Inconel 718 (including but not limited to the nickel-chromium alloy Inconel 718) is proposed as the additive manufacturing material. The specific steps are as follows: (a) filling the printing chamber with inert gas to minimize oxidation of the metal powder; (b) laying a thin layer of nickel-chromium alloy powder on the surface of the printing platform, and using a laser to scan the cross-section of the porous layer 4 and the metal layer 3 to be printed to melt and sinter the nickel-chromium alloy powder; (c) moving the printing platform downward, re-laying the nickel-chromium alloy powder, repeating step b to complete the preliminary printing; (d) standing for a period of time, waiting for the printing chamber to cool to room temperature, removing excess nickel-chromium alloy powder, and obtaining a high-strength integrated three-dimensional structure porous layer 4 and metal layer 3.

[0041] The transpiration cooling device's liquid chamber 1 utilizes a segmented pressurization design. A regulating valve 6 in the pressurized delivery network adjusts the supply pressure of the cooling medium 12 to different liquid chambers, achieving corresponding matching between high, medium, and low heat flux regions. This allows for active regulation of the supply pressure of the cooling medium 12, enabling precise delivery of the cooling medium 12. The liquid chamber 1 can be fabricated using conventional machining and then assembled with the metal layer 3 through welding to create a transpiration cooler.

[0042] In order to solve the problem of "steam blockage" caused by insufficient driving force of the cooling medium 12 during the cooling process of the aircraft nose cone, the booster transmission pipeline network adopts an electric heating active pressurization method to ensure the efficient delivery of the cooling medium 12. The booster transmission pipeline network consists of a booster air chamber 10, a liquid storage chamber 7, a pipeline 5, a booster piston 8 and a regulating valve 6. The booster piston 8 divides the entire cavity into the booster air chamber 10 and the liquid storage chamber 7. The movement of the booster piston 8 will cause the volume of the booster air chamber 10 and the liquid storage chamber 7 to change accordingly. The cooling medium 12 in the liquid storage chamber 7 is injected into the liquid separation chamber 1 through the pipeline 5 under the drive of the booster piston 8. In order to ensure the electric heating expansion effect of the inert gas in the booster air chamber 10, the booster piston 8 and the entire cavity are made of high-temperature resistant low-thermal conductivity materials to minimize heat leakage from the booster air chamber 10.

[0043] Electric heating causes the gas in the pressurized air chamber 10 to undergo a thermal expansion effect, driving the piston to move and increase the pressure of the cooling medium 12 in the liquid storage chamber 7, thereby realizing the delivery and control of the cooling medium 12. The electric heating pressurized delivery method overcomes the problems of the existing high-pressure gas cylinder pressurization, such as the additional heavy load and the difficulty in ensuring reliability in the pump-driven pressurized space state. In addition, considering the uneven aerodynamic heat distribution in different areas of the aircraft nose cone, a segmented pressurization design concept matching the aerodynamic heat flow is adopted, and multiple liquid separation chambers 1 are deployed on both sides along the leading edge of the nose cone, and the pressure of the liquid separation chamber 1 is controlled by the regulating valve 6. It should be pointed out that when the cooling medium 12 is actually operating in the pressurized delivery network, it is necessary to adjust the valve opening of the liquid separation chamber 1 into the pipe according to the temperature signal fed back by the temperature sensors pre-buried at different positions of the sweating cooling device, so as to realize precise pressurization control of each liquid separation chamber based on the distribution of the ambient aerodynamic heat flow.

[0044] The booster transmission network uses a first-order active disturbance rejection control method to adjust the opening of the liquid chamber control valve 6 (the three control valves 601, 602, and 603 are independently controlled) to achieve the flow control of the coolant 12 in the liquid chamber 1 of the transpiration cooling thermal protection device. The first-order active disturbance rejection control method uses a data-driven extended state observer (ESO) to observe the total disturbance of the system by evaluating feedback data. Its control structure is as follows: Figure 4 As shown. Taking into account parameter disturbances (external ambient temperature and pressure fluctuations during long-duration flight, as well as internal coolant delivery pressure and temperature disturbances), system nonlinearity (the nonlinear relationship between the average surface temperature of the transpiration cooling thermal protection device and the opening of the regulating valve), and interference (instability of the external aerodynamic thermal environment), the following nonlinear model can be constructed:

[0045]

[0046] The control system output y (the average temperature of each heat flow region) is considered the system state variable x. d represents the total system disturbance. u is the control variable, i.e., the control signal for regulating valve opening, used to adjust the opening of regulating valve 6. g is a nonlinear function representing the instability and nonlinearity of the system. The control parameter b is replaced by the estimated value b0.

[0047]

[0048] Among them, all uncertainties and disturbances can be set in the total disturbance: δ = g(x) + d(t) + (b-b0)u.

[0049] To estimate the total disturbance, the extended model of formula (2) can be expressed as;

[0050]

[0051] Among them, the expansion parameter x2 is introduced to represent δ. Based on the assumption of the expansion amount, the ESO is constructed as follows:

[0052]

[0053] Where L = [L1 L2] is the observer parameter, z1 is the estimated value of the control system output value y, which represents the average temperature of each heat flow area; z2 is the estimated value of the total disturbance; is the derivative of z1; is the derivative of z2; b0 is b n By referring to the observer bandwidth ω0, the pole assignment method is used to improve the accuracy and tuning convenience of the observer, resulting in:

[0054]

[0055] By compensating the estimated δ and eliminating disturbances to ensure control quality, the control law can be simplified to:

[0056]

[0057] Therefore, although external disturbances occur, they are sufficient to eliminate the operating errors.

[0058] u0=k(r-z1) (7)

[0059] Where r is the set point of temperature and k is the proportional gain.

[0060] To achieve faster observation efficiency and satisfactory tracking performance, the observation frequency should be faster than the control frequency. Therefore, the observation bandwidth value and proportional gain are adjusted to C (including but not limited to 0.5) and D (including but not limited to 0.2) respectively, but C>D must be ensured.

[0061] Through the above steps, the first-order anti-disturbance control method is introduced to match the opening of the regulating valve 6 according to the heat flow area on the outer surface of the transpiration cooler, so as to realize the regulation of the cooling medium flow supply of the liquid chamber 1 of the transpiration cooling thermal protection device and ensure efficient uniform temperature cooling of the nose cone part of the aircraft.

[0062] like Figure 5 As shown, the working principle of the transpiration cooling thermal protection device is as follows:

[0063] When a high-temperature heat flow comes, the heating wire 9 in the boost delivery network begins to heat the inert gas stored in the boost air cavity 10, causing an expansion effect, driving the boost piston 8 to move to increase the pressure of the cooling medium 12 in the liquid storage cavity 7, and adjusting the opening of the regulating valve 6: the flow resistance of the cooling medium 12 corresponding to the liquid separation cavity 1 is large, and the self-disturbance rejection controller controls the opening of the regulating valve 601 corresponding to the liquid separation cavity 101 to be large; the flow resistance of the cooling medium 12 corresponding to the liquid separation cavity 103 is small, and the self-disturbance rejection controller controls the opening of the regulating valve 603 corresponding to the liquid separation cavity 103 to be small, thereby ensuring precise control of the cooling medium 12. The cooling medium 12 is transported to the liquid separation chamber 1 through the pipe 5 in the pressurized transmission network, and then reaches the complex network flow channel in the porous layer 4 through the discrete microgrooves 2 configured in the metal layer 3. It penetrates and flows in the complex network flow channel to carry out sufficient fluid-solid heat exchange. The cooling medium 12 continuously overflows from the heated porous layer 4 like sweat, forming a relatively uniform thermal insulation film (such as a liquid film) on the outer surface of the porous layer 4 (that is, the aircraft surface) and wrapping the aircraft surface. The thermal insulation film absorbs heat in the high-temperature heat flow and generates high-temperature steam 14 to escape, thereby providing thermal protection for the aircraft nose cone.

[0064] Therefore, such a porous network transpiring cooling thermal protection device ensures the precise delivery of the cooling medium 12 of the aircraft nose cone and realizes uniform temperature cooling of the aircraft nose cone part through the stepped design of the number and depth of the discrete microgrooves 2 of the metal layer 3, the stepped design of the pores of the porous layer 4, and the segmented pressurization design of the liquid chamber 1. Electric heating is used to cause the gas in the pressurized air chamber 10 to undergo a thermal expansion effect, driving the piston 8 to move and provide the supply pressure of the cooling medium 12 in the liquid storage chamber 7, overcoming the problems of the additional heavy load of the existing high-pressure gas cylinder pressurization and the difficulty in ensuring reliability in the pump-driven pressurized space state. A first-order self-anti-disturbance controller is introduced to control the opening of the regulating valve 6 to realize the delivery and regulation of the cooling medium 12. The entire transpiring cooling thermal protection device has high cooling efficiency and strong uniform temperature cooling capacity, can reduce the weight of the aircraft, and has broad application prospects.

[0065] Usually in aircraft, the thermal environment at the top of the leading edge body such as the nose cone, the leading edge of the rudder and the leading edge of the wing is more severe, and it is subjected to more severe thermal and mechanical loads, so the above-mentioned porous network sweating cooling thermal protection device can be used.

[0066] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features therein. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A porous network transpiration cooling thermal protection device, comprising a transpiration cooler and a pressurized delivery network, wherein the transpiration cooler comprises a porous layer, a metal layer, and a liquid separation layer, wherein the metal layer is provided with discrete microgrooves connecting the porous layer and the liquid separation layer, and the liquid separation layer is connected to the pressurized delivery network, characterized in that: The transpiration cooler is divided into at least two heat flow regions according to different heat flow levels; the pores of the porous layer are distributed in a stepped manner according to the different heat flow regions of the transpiration cooler; a liquid separation cavity corresponding to each heat flow region is provided in the liquid separation layer, and the booster delivery pipe network reduces the supply of cooling medium in each liquid separation cavity as the heat flow level of the corresponding heat flow region decreases; The boost delivery pipeline network includes a boost air chamber, a liquid storage chamber, a pipeline, a piston, a regulating valve and a controller; the piston is located between the boost air chamber and the liquid storage chamber; the boost air chamber is provided with gas that expands after being heated and an electric heating element for heating the gas; a regulating valve is provided on the pipeline connecting each liquid separation chamber, and the controller is used to control the opening of the regulating valve to adjust the supply of each liquid separation chamber.

2. The porous network sweating cooling heat protection device according to claim 1, characterized in that: The porous layer consists of regular vertical flow channels and through flow channels; the pore diameters of the through flow channels are the same in different heat flow areas, the pores of the vertical flow channels are distributed in a stepped manner, large-pore network flow channels are configured in high heat flow areas, and low-pore network flow channels are configured in low heat flow areas.

3. The porous network sweating cooling heat protection device according to claim 2, characterized in that: The cross section of the vertical flow channel is circular, square or triangular; the cross section of the through flow channel is circular, square or triangular.

4. The porous network sweating cooling heat protection device according to claim 1, characterized in that: The number of the discrete microgrooves in the metal layer is distributed in a stepped manner.

5. The porous network sweating cooling heat protection device according to claim 4, characterized in that: The discrete microgrooves are also distributed in steps in depth; in a high heat flux region, the discrete microgrooves penetrate the porous layer; and in a low heat flux region, the discrete microgrooves do not penetrate the porous layer.

6. The porous network sweating cooling heat protection device according to claim 5, characterized in that: The cross section of the discrete microgrooves is circular, square or triangular.

7. The porous network sweating cooling heat protection device according to claim 1, characterized in that: The transpiring cooler is divided into three heat flow areas according to different heat flow levels, namely a high heat flow area, a medium heat flow area and a low heat flow area.

8. The porous network sweating cooling heat protection device according to claim 1, characterized in that: The controller uses the arithmetic average measurement value of the temperature of each area of the sweat cooler as a feedback signal, and achieves the purpose of supplying the cooling medium flow to each liquid separation cavity by adjusting the opening of the regulating valve; the controller includes an expanded state observer of formula (1): Where z1 is the estimated value of the control system output value y, which represents the average temperature of each heat flow area; z2 is the estimated value of the total disturbance; is the derivative of z1; is the derivative of z2; b0 is b n Estimates, P n is the object open-loop gain, T n is the time constant; u is the control variable, representing the opening signal of each regulating valve; L1 and L2 are the observer parameters.

9. The porous network sweating cooling heat protection device according to claim 8, characterized in that: The values of observer parameters L1 and L2 are obtained by tuning equation (2): In formula (2), ω0 is the bandwidth of the extended state observer.

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