A passive thermal intelligent structure that can switch between heat dissipation and thermal insulation

Abstract

This invention belongs to the field of spacecraft thermal protection, specifically relating to a passive thermally intelligent structure that can switch between heat dissipation and thermal insulation. This invention achieves switching between "high thermal conductivity heat dissipation" and "low thermal conductivity thermal insulation" operating states at specific temperatures through configuration changes. By adjusting the compression displacement during assembly, a pre-compression bending moment can be formed at the contact surface, thereby controlling the critical trigger temperature for state switching. When the temperature inside the thermally intelligent structure is below the critical trigger temperature, the upper and lower heat-conducting pillars connected to the bimetallic strip, as well as the upper and lower heat-conducting shells, remain in complete contact, forming a high thermal conductivity channel; at this time, the thermally intelligent structure is in the "high thermal conductivity heat dissipation" state. Once the temperature exceeds the trigger temperature, the bimetallic strip deforms under the action of the thermal bending moment, pushing the upper and lower heat-conducting pillars and the upper and lower heat-conducting shells out of contact. The main heat conduction path is cut off, the equivalent thermal conductivity of the thermally intelligent structure drops rapidly, and the thermally intelligent structure switches to the "low thermal conductivity thermal insulation" state.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft thermal protection, specifically relating to a passive thermal intelligent structure that can switch between heat dissipation and thermal insulation. Background Technology

[0002] With the continuous development of aerospace technology, the equipment carried by spacecraft is becoming increasingly miniaturized and integrated; the working environment they face is becoming increasingly complex. When exposed to high-intensity heat flow impacts such as high-energy laser irradiation, severe temperature gradients can easily form in localized areas, inducing material performance degradation and even structural failure. To suppress the temperature rise in the initial stage of thermal shock, the protective structure needs to have strong thermal insulation capabilities; during long-term normal service without strong thermal shocks, it must also be able to effectively dissipate heat to avoid overall temperature runaway caused by internal heat accumulation. This requires intelligent thermal control structures that can intelligently switch between thermal insulation and thermal conduction states according to changes in external temperature.

[0003] Current protective structure designs for high heat flux environments largely rely on low thermal conductivity insulation materials or multi-layer thermal protection systems to reduce heat transfer to the internal structure. While these solutions are effective in suppressing short-term thermal shock, they also significantly reduce the structure's heat dissipation capacity, easily leading to heat accumulation problems under repeated or long-term service conditions. Active thermal control structures, although capable of precise heat flux regulation, have limitations in long-term reliability due to the need for external power supply. For example, the patent "Method for Forming a Thermal Switch" (CN109312975B) proposes an air-gap active thermal switch control method based on the difference in thermal expansion of materials, achieving efficient regulation of heat flux interruption in extremely low-temperature environments. However, this design only considers extremely low-temperature (5~20K) operating scenarios and requires additional air extraction and supply devices, resulting in high system complexity and large size, which is necessary to meet the miniaturization and high stability requirements of aerospace equipment.

[0004] Thermally intelligent materials with adjustable thermal conductivity are materials that can autonomously change their thermal conductivity in response to external stimuli. They can adjust between different thermal conductivity states without external energy input and play an important role in the thermal management system of spacecraft in complex thermal environments.

[0005] Based on their different regulation mechanisms, thermally intelligent materials can be categorized into three types: field-driven, phase change material (PCM), and structurally reconfigurable. Typical field-driven thermally intelligent materials, such as ferroelectric materials, can induce domain reversal and rearrangement under a strong electric field, thereby adjusting the thermal conductivity by changing the mean free path of phonons. PCM-type thermally intelligent materials achieve abrupt changes in thermal conductivity through solid-liquid phase transitions or changes in the conformation of different polymers via a temperature field. For example, polymers such as hexagonal sulfides can achieve a reversible 200% jump in thermal conductivity by switching between a low-temperature diamagnetic phase and a high-temperature paramagnetic phase. Structurally reconfigurable thermally intelligent structures (mechanical metamaterials) rely on the expansion, contraction, or deformation of their moving parts, utilizing the contact and separation of physical surfaces to open and close heat transfer paths, thus achieving significant adjustments in thermal conductivity. This type of thermally intelligent structure has a wider range of thermal conductivity adjustment compared to field-driven and PCM-type materials, and has greater application potential in spacecraft thermal protection systems.

[0006] Existing reconfigurable thermal intelligent structures mainly include micro-slit types, shape memory alloy types, origami structures, and bimetallic types. Micro-slit thermal intelligent structures initially possess a micro-gap at the micrometer level. Upon heating, the gap is eliminated by the structure's own thermal expansion, switching the structure from a low thermal conductivity state to a high thermal conductivity state. For example, the patent "Dual-drive Space Thermal Switch for Spacecraft Based on Phase Change Materials and Metal Micro-expansion" (CN111552327A) proposes a passive thermal switch that utilizes a dual mechanism of micro-expansion and phase change materials. Its structure is simple and highly reliable. However, its response speed is slow, requiring 8.4 minutes to activate the thermal switch, making it difficult to provide timely protection against sudden heat flows. Shape memory alloy types change the structural configuration by switching between martensite and austenite, thereby adjusting the equivalent thermal conductivity of the structure. Origami structures adjust the equivalent thermal conductivity by changing the heat transfer path length through compression and folding states. The bimetallic strip-type thermal smart structure relies on the thermal bending moment generated by the difference in thermal expansion coefficients between the high-expansion layer and the low-expansion layer of the highly thermally sensitive bimetallic strip to drive the change of the heat conduction path or form a thermal insulation gap. Since its response time is only affected by the external temperature field, it has a faster adjustment speed than shape memory alloys, external field driven materials and phase change materials, making it very suitable for protecting against high-speed heat flow impact. Summary of the Invention

[0007] This invention provides a passive thermal intelligent structure that can switch between heat dissipation and heat insulation, aiming to solve the problems in the prior art.

[0008] The technical solution adopted by this invention to solve its technical problem is: A passive thermal intelligent structure with switchable heat dissipation and heat insulation includes a panel, a support column, a thermally conductive shell, and a bimetallic strip.

[0009] The aforementioned panel is a thin circular plate, divided into an upper panel and a lower panel. The heat-conducting outer shell is an annular cylindrical metal shell, with four symmetrical rectangular protrusions with slots integrally manufactured with the heat-conducting outer shell as heat-conducting pillars on its inner side, ensuring a snap-fit ​​connection with the bimetallic strip. The heat-conducting outer shell is divided into an upper heat-conducting outer shell with upper heat-conducting pillars and a lower heat-conducting outer shell with lower heat-conducting pillars. The upper and lower heat-conducting outer shells are connected by free surface contact, and the contact surfaces are pressed together by a pre-compression bending moment to ensure a tight fit. The upper panel is fixedly connected to the upper heat-conducting outer shell, and the lower panel is fixedly connected to the lower heat-conducting outer shell.

[0010] The support column is a rectangular column with slots on all four sides, located at the center of the lower panel. The lower surface of the support column is fixedly connected to the upper surface of the lower panel, while its upper surface is freely connected to the lower surface of the upper panel. The bimetallic strip consists of four curved beams stamped from bimetallic flat plates, with the main body of the curved beams being arc-shaped. For ease of processing, the curved beams are processed in two sections. Each section has an additional straight extension without any curvature on both sides to facilitate assembly and the application of preload bending moment. The first section of the curved beam is a complete arc-shaped stamped curved beam with extensions. One end of the extension connects to the slot and tenon of the upper heat-conducting column, and the other end connects to the slot and tenon of the metal connecting block. The second section of the curved beam is a semi-circular arc-shaped stamped curved beam with extensions. One end connects to the slot and tenon of the metal connecting block, and the other end connects to the slot and tenon of the support column.

[0011] The panel and support column are made of 304 stainless steel with low thermal conductivity, and the heat-conducting outer shell is made of 1070 aluminum alloy with high thermal conductivity. The bimetallic strip is made of 5J39110 bimetallic strip, with its high expansion layer being Mn72Ni10Cu18 alloy, which has a theoretical thermal expansion coefficient of 25.2 ppm / ℃, and its low expansion layer being Ni36 alloy, which has a theoretical thermal expansion coefficient of 1.9 ppm / ℃.

[0012] The radius of curvature of the curved beam is not less than half the arc span, which can be equivalent to a central angle of not more than 180°. The purpose is to reduce the springback of the bimetallic strip after stamping and ensure that the structure can be stamped smoothly.

[0013] The beneficial effects of this invention are: This invention achieves switching between "high thermal conductivity heat dissipation" and "low thermal conductivity heat insulation" operating states at specific temperatures through configuration changes. By adjusting the compression displacement during assembly, a pre-compression bending moment can be formed at the contact surface, thereby controlling the critical trigger temperature for state switching. When the temperature inside the thermally intelligent structure is below the critical trigger temperature, the upper and lower heat-conducting pillars connected to the bimetallic strip, as well as the upper and lower heat-conducting shells, remain in complete contact, forming a high thermal conductivity channel. At this time, the thermally intelligent structure is in the "high thermal conductivity heat dissipation" state. Once the temperature exceeds the trigger temperature, the bimetallic strip deforms under the action of thermal bending moment, pushing the upper and lower heat-conducting pillars and the upper and lower heat-conducting shells out of contact. The main heat conduction path is cut off, the equivalent thermal conductivity of the thermally intelligent structure drops rapidly, and the thermally intelligent structure switches to the "low thermal conductivity heat insulation" state.

[0014] Based on the above technical solution, the present invention can be further improved as follows.

[0015] Furthermore, where there are no strict requirements on the weight of the thermally intelligent structure, the thermally conductive shell material can be replaced from 1070 aluminum alloy to T2 copper alloy.

[0016] The beneficial effect of adopting the above-mentioned further solution is that during use, the thermal conductivity of the thermal intelligent structure in the "high thermal conductivity heat dissipation" (thermal conduction path connection) state is improved, thereby improving the on / off ratio of the thermal intelligent structure.

[0017] Furthermore, the support column and the lower panel can be integrally formed by machining. The contact surfaces between the upper panel and the upper heat-conducting column, and between the lower panel and the lower heat-conducting column, are bolted together by tapping, and thermally conductive adhesive is applied to the interface.

[0018] The beneficial effect of adopting the above-mentioned further solution is that during use, the contact thermal resistance of the contact surface can be reduced, the thermal conductivity of the thermal intelligent structure in the "heat dissipation" state can be improved, and thus the switching ratio can be improved.

[0019] Furthermore, the surfaces of the aforementioned thermal smart structures can be smoothly polished and coated with a coating that reduces heat radiation.

[0020] The beneficial effect of adopting the above-mentioned further solution is that during use, the heat transfer of thermal radiation is reduced, the thermal conductivity of the thermal intelligent structure in the "insulation state" is reduced, and thus the on / off ratio of the thermal intelligent structure is improved.

[0021] Based on the above reasons, this invention can be applied and promoted in the field of spacecraft thermal protection. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the thermally intelligent structure in the "high thermal conductivity heat dissipation" state.

[0023] Figure 2This is a schematic diagram of the thermally intelligent structure in the "low thermal conductivity insulation" state.

[0024] Figure 3 This is a cross-sectional view of the overall assembly of the thermal intelligent structure.

[0025] Figure 4 A top view of the thermally intelligent structure to conceal the top plate.

[0026] Figure 5 The following are three views of the first curved beam of the bimetallic strip, where (a) is the front view, (b) is the side view, and (c) is the top view.

[0027] Figure 6 The following are three views of the second curved beam of the bimetallic strip, where (a) is the front view, (b) is the side view, and (c) is the top view.

[0028] Figure 7 The following are three views of the lower panel and supporting column structure, where (a) is the top view, (b) is the side view, and (c) is the front view.

[0029] Figure 8 A schematic diagram of the application of preload bending moment to a bimetallic strip.

[0030] In the diagram: 1 Upper heat-conducting column; 2 Lower heat-conducting column; 3 Upper heat-conducting outer shell; 4 Lower heat-conducting outer shell; 5 Bimetallic strip; 6 Support column; 7 Upper panel; 8 Lower panel; 9 Metal connecting block; 10 First curved beam; 11 Second curved beam; 12 High expansion layer of the first curved beam; 13 Low expansion layer of the first curved beam; 14 Low expansion layer of the second curved beam; 15 High expansion layer of the second curved beam. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0032] Figure 1The diagram shows the internal structure of the thermally intelligent structure hidden in the upper panel, illustrating the assembly relationship of the internal structure under high thermal conductivity conditions. In this embodiment, the upper thermally conductive pillar 1, made of aluminum alloy, and the annular upper thermally conductive shell 3, made of aluminum alloy, are integrally manufactured. The lower thermally conductive pillar 2, made of aluminum alloy, and the annular lower thermally conductive shell 4, also made of aluminum alloy, are integrally manufactured. The upper thermally conductive shell 3 and the lower thermally conductive shell 4 both have a thickness of 1.5 mm, an outer diameter of 82 mm, and an inner diameter of 79 mm. The upper thermally conductive pillar 1 and the lower thermally conductive pillar 2, as well as the upper thermally conductive shell 3 and the lower thermally conductive shell 4, are in free surface contact. To reduce the contact thermal resistance, thermal grease can be applied to the contact surfaces. Under high thermal conductivity conditions, the contact surfaces are tightly fitted under the action of pre-compression bending moment, allowing heat flow to be smoothly transferred from the upper panel 7 to the lower panel 8 along the upper thermally conductive pillar 1 and the lower thermally conductive pillar 2. The detailed assembly relationship between the stainless steel support pillar 6 and the bimetallic strip 5 formed by stamping bimetallic strips is shown below. Figure 3 As shown.

[0033] Figure 2 The diagram shows the assembly relationship of the internal structure of the thermally intelligent structure under low thermal conductivity. After being impacted by external heat flow, the bimetallic strip 5 deforms, causing the contact surfaces between the upper heat-conducting column 1 and the lower heat-conducting column 2, and between the upper heat-conducting shell 3 and the lower heat-conducting shell 4 to separate. This generates a thermally insulating micro-gap, which cuts off the main heat transfer path and reduces the overall thermal conductivity of the structure.

[0034] Figure 3 The image shown is a half-section view of the thermal smart structure. Figure 4 The top view of the thermal intelligent structure, concealing the top plate, shows the specific connection relationships of the upper and lower panels, upper and lower heat-conducting pillars, support pillars, and bimetallic strip. The overall radius of this thermal intelligent structure is 41mm; the normal height (overall thickness) is 12mm, with the upper panel 7 and lower panel 8 having a normal height (thickness) of 1mm, and the upper heat-conducting pillar 1 and lower heat-conducting pillar 2 having a normal height of 5mm. This thermal intelligent structure is a quarter-symmetric structure. The maximum radial length of the upper heat-conducting pillar 1 and lower heat-conducting pillar 2 is 3mm, and their width is 10mm. A 10mm groove is formed on the upper heat-conducting pillar 1. A rectangular groove with a diameter of 0.6mm and a depth of 1mm is provided. The upper edge of the groove is 3mm from the lower surface of the upper panel. This groove is connected to the extension of the first curved beam 10. The support column 6 is a 14mm... 14mm A 304 stainless steel cuboid with slots on all four sides, each 10mm thick. A rectangular groove with a diameter of 0.6mm and a depth of 1mm. The upper edge of the groove is 1mm from the lower surface of the upper panel. This groove connects to the extension of the second curved beam.

[0035] Figure 3In this embodiment, the bimetallic strip 5 is further subdivided into three parts according to the actual processing and assembly relationship: a metal connecting block 9, a first curved beam 10, and a second curved beam 11. The metal connecting block 9 is a 3mm... 12mm A 1.6mm thick rectangular block with slots on both sides, made of 1070 aluminum alloy, with 10mm slots. A rectangular groove with a diameter of 0.6mm and a depth of 1mm is used to connect the first curved beam 10 and the second curved beam 11. The first curved beam 10 is composed of a high-expansion layer 12 and a low-expansion layer 13; the second curved beam 11 is composed of a low-expansion layer 14 and a high-expansion layer 15. The specific processing methods are described below. Figure 5 and Figure 6 As shown.

[0036] Figure 5 The image shows the three views of the first curved beam segment 10. Without preload bending moment, the first curved beam segment 10 has a diameter of 22.6 mm. 10mm A 0.6mm thick 5J39110 bimetallic strip is stamped, with a main arc span of 20mm, an arch height of 2mm, a radius of curvature of 26mm, and horizontal extensions at both ends of 1mm in length. The high-expansion layer 12 of the first curved beam is located inside the arc, with a thickness of 0.3mm and made of Mn72Ni10Cu18 alloy; the low-expansion layer 13 of the first curved beam is located outside the arc, with a thickness of 0.3mm and made of Ni36 alloy. The high-expansion layer 12 and the low-expansion layer 13 of the first curved beam have the same thickness. When applying the preload bending moment, it is only necessary to lengthen the horizontal extension connected to the slot of the upper heat-conducting column 1 by a specific length. For example, if a preload displacement of 0.2mm is required, the horizontal extension connected to the slot of the upper heat-conducting column 1 is machined to a length of 1.2mm, while the extension at the other end remains machined to a length of 1mm.

[0037] Figure 6 These are the three views of the second curved beam segment 11. The second curved beam segment 11 is made of 11.3mm... 10mm A 0.6mm thick 5J39110 bimetallic strip is stamped, with a semicircular arc span of 10mm, an arch height of 2mm, a radius of curvature of 26mm, and horizontal extensions at both ends of 1mm in length. The low-expansion layer 14 of the second curved beam is located on the outer side of the semicircular arc, with a thickness of 0.3mm and made of Ni36 alloy; the high-expansion layer 15 of the second curved beam is located on the inner side of the semicircular arc, with a thickness of 0.3mm and made of Mn72Ni10Cu18 alloy. The low-expansion layer 14 and the high-expansion layer 15 of the second curved beam have the same thickness.

[0038] Figure 7 The images show the three views of the support column 6 and the lower plate 8. The lower plate has a radius of 41mm and a normal height (thickness) of 1mm. The support column 6 has a dimension of 14mm. 14mm 10mm, with 10mm machining on all four sides. A rectangular groove with a diameter of 0.6mm and a depth of 1mm is formed. The upper edge of the groove is 1mm away from the top surface of the support column, and the side of the groove is 2mm away from the edge of the support column. The groove is connected to the connecting section of the second curved beam 11 by a tenon.

[0039] Figure 8 This is a schematic diagram of the application of preload bending moment. At the slot connected to the upper heat-conducting column 1, a specific preload strain is formed by extending the first curved beam 10. At the contact surface, a pre-compression bending moment M corresponding to the pre-compression strain value is formed. Only when the temperature exceeds the corresponding trigger temperature will the thermal bending moment of the bimetallic strip 5 overcome the pre-compression bending moment M, drive the contact surface to separate, and realize the switching between heat dissipation and heat insulation states of the thermal intelligent structure.

[0040] This intelligent structure can switch from a high thermal conductivity heat dissipation state to a low thermal conductivity insulation state when subjected to thermal shock via a bimetallic strip. Thanks to the relatively independent components of the heat-conducting outer shell, heat-conducting pillars, and the bimetallic strip driving the deformation of the thermal intelligent structure, this structure offers greater design flexibility in heat transfer performance compared to materials like origami. Using Abaqus simulations, the equivalent thermal conductivity of this structure in the "high thermal conductivity heat dissipation" state is 3.25 W / (m·K), which meets the heat dissipation requirements under normal service conditions; the equivalent thermal conductivity in the "low thermal conductivity insulation" state is 0.0162 W / (m·K), providing insulation during thermal shock. The overall on / off ratio of the thermal intelligent structure is 197.0, providing a sufficiently large adjustment range.

[0041] The thermal driving force for the switching of the thermally intelligent structure's state is the thermal bending moment generated by the difference in thermal expansion coefficients between the high and low expansion layers of the bimetallic strip when subjected to thermal stimulation. This thermal bending moment lifts the upper heat-conducting pillar, the upper heat-conducting outer shell, and the upper panel, forming an insulating gap between the upper and lower heat-conducting pillars and the upper and lower heat-conducting outer shells, thus reducing the equivalent thermal conductivity of the thermally intelligent structure. Without additional constraints, the upper and lower parts of the heat-conducting outer shell can easily separate. To control the trigger temperature for the separation of the upper and lower heat-conducting pillars, a pre-compression bending moment needs to be introduced. This is achieved by specifically lengthening the extension section of the bimetallic strip connected to the upper heat-conducting pillar. During assembly with the slot of the upper heat-conducting pillar, due to the interference fit, a pre-compression bending moment is generated in the opposite direction to the thermal bending moment generated by the bimetallic strip after heating. When the thermally intelligent structure is subjected to thermal shock, the thermal bending moment of the bimetallic strip must first overcome the pre-compression bending moment generated by the assembly. Only when the temperature rises above the corresponding trigger temperature will the contact surfaces of the upper and lower heat-conducting pillars and the upper and lower heat-conducting shells separate, causing the equivalent thermal conductivity of the thermally intelligent structure to decrease. Therefore, by forming a specific amount of pre-compression bending moment through interference fitting, a specific trigger temperature for switching from a high thermal conductivity state to a low thermal conductivity state can be set. For example, Abaqus simulations show that when the pre-compression displacement is 0.1 mm, the trigger temperature of the thermally intelligent structure is 158.6℃; when the pre-compression displacement is 0.2 mm, the trigger temperature is 196.5℃; and when the pre-compression displacement is 0.3 mm, the trigger temperature is 225.4℃. This demonstrates that the thermally intelligent structure can flexibly achieve the trigger temperature for switching thermal conductivity states.

[0042] This structure can be combined with a high thermal conductivity heat spreader and phase change materials to form a composite thermal shock protection system. The high thermal conductivity heat spreader, placed at the top of the thermal protection system, rapidly disperses high-density heat flow to prevent localized overheating and structural burnout. The phase change material, placed in the middle layer, absorbs heat through phase change. A passive thermally intelligent structure, capable of switching between heat dissipation and insulation, is placed at the bottom layer. Upon thermal shock, it quickly switches from a high thermal conductivity state to a low thermal conductivity state, cutting off heat flow downwards and protecting valuable equipment such as internal electronic components. After the heat is absorbed by the phase change material and the thermal protection system temperature returns to normal, the passive thermally intelligent structure switches back from a low thermal conductivity state to a high thermal conductivity state, allowing heat generated by internal electronic components during normal operation to still be dissipated. This thermal protection system can respond to changes in the external temperature field, achieving intelligent and autonomous switching between heat dissipation and insulation states.

Claims

1. A passive thermal intelligent structure with switchable heat dissipation and heat insulation, characterized in that, The aforementioned passive thermal intelligent structure with switchable heat dissipation and heat insulation includes a panel, support columns, a heat-conducting shell, and a bimetallic strip; The aforementioned panel is a thin circular plate, divided into an upper panel and a lower panel; the aforementioned heat-conducting outer shell is an annular cylindrical metal shell, with four rectangular protrusions with slots symmetrically arranged on its inner side, which are integrally manufactured with the heat-conducting outer shell as heat-conducting pillars to ensure a snap-fit ​​connection with the bimetallic strip; the heat-conducting outer shell is divided into an upper heat-conducting outer shell with an upper heat-conducting pillar and a lower heat-conducting outer shell with a lower heat-conducting pillar. The upper heat-conducting outer shell and the lower heat-conducting outer shell are connected by free surface contact, and the contact surfaces are pressed together by a pre-compression bending moment to ensure a tight fit; The upper panel is fixedly connected to the upper heat-conducting outer shell, and the lower panel is fixedly connected to the lower heat-conducting outer shell; The support column is a rectangular column with slots on all four sides, located at the center of the lower panel. The lower surface of the support column is fixedly connected to the upper surface of the lower panel, while its upper surface is freely connected to the lower surface of the upper panel. The bimetallic strip consists of four curved beams stamped from bimetallic flat plates, with the main body of the curved beams being arc-shaped. The curved beams are processed in two sections, with each section having an additional straight extension without any curvature on both sides. The first section of the curved beam is a complete arc-shaped stamped curved beam with an extension, one end of which is connected to the slot and tenon of the upper heat-conducting column, and the other end is connected to the slot and tenon of the metal connecting block. The second section of the curved beam is a semi-circular arc-shaped stamped curved beam with an extension, one end of which is connected to the slot and tenon of the metal connecting block, and the other end is connected to the slot and tenon of the support column.

2. The passive thermal intelligent structure with switchable heat dissipation and heat insulation as described in claim 1, characterized in that, The panel and support column are made of low thermal conductivity 304 stainless steel, and the thermally conductive shell is made of high thermal conductivity 1070 aluminum alloy; the bimetallic strip is made of 5J39110 bimetallic strip, and its high expansion layer is Mn72Ni10Cu18 alloy.

3. The passive thermal intelligent structure with switchable heat dissipation and heat insulation as described in claim 1, characterized in that, The radius of curvature of the curved beam is not less than half the span of the circular arc.

4. The passive thermal intelligent structure with switchable heat dissipation and heat insulation according to claim 2, characterized in that, The heat-conducting outer shell material was changed from 1070 aluminum alloy to T2 copper alloy.

5. The passive thermal intelligent structure with switchable heat dissipation and heat insulation according to claim 1, characterized in that, The support column and the lower panel are integrally formed by machining. The contact surfaces between the upper panel and the upper heat-conducting column, and between the lower panel and the lower heat-conducting column, are bolted together by tapping, and thermally conductive adhesive is applied to the contact surfaces.

6. The passive thermal intelligent structure with switchable heat dissipation and heat insulation according to claim 1, characterized in that, The surfaces of the aforementioned thermal intelligent structures are all smoothed and coated with a coating to reduce heat radiation.

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