CN-122009535-A - Heat dissipation-heat insulation switchable passive thermal intelligent structure

CN122009535ACN 122009535 ACN122009535 ACN 122009535ACN-122009535-A

Abstract

The invention belongs to the field of heat protection of spacecrafts, and particularly relates to a heat dissipation-heat insulation switchable passive heat intelligent structure. The invention realizes the switching between the working states of high heat conduction and radiation and low heat conduction and insulation at a specific temperature through the change of the configuration. By adjusting the compression displacement during assembly, a pre-compression bending moment can be formed on the contact surface, so that the critical trigger temperature of state switching is controlled. When the internal temperature of the thermal intelligent structure is lower than the critical trigger temperature, the upper and lower heat conducting columns and the upper and lower heat conducting shells connected to the bimetallic strip are kept in full contact to form a high heat conducting channel, and the thermal intelligent structure is in a high heat conducting and radiating state. Once the temperature exceeds the trigger temperature, the bimetallic strip deforms under the action of the thermal bending moment to push the upper and lower heat conducting columns and the upper and lower heat conducting shells to be separated from contact, the main heat conducting passage is cut off, the equivalent heat conducting coefficient of the heat intelligent structure is rapidly reduced, and the heat intelligent structure is switched to a low heat conducting heat insulation state.

Inventors

ZHANG YONGCUN
LI ZIQIANG
YANG ZIHAO

Assignees

大连理工大学

Dates

Publication Date: 20260512
Application Date: 20260323

Claims (6)

1. The heat dissipation-heat insulation switchable passive heat intelligent structure is characterized by comprising a surface plate, a support column, a heat conduction shell and a bimetallic strip; The heat-conducting shell is divided into an upper heat-conducting shell with an upper heat-conducting column and a lower heat-conducting shell with a lower heat-conducting column, the upper heat-conducting shell and the lower heat-conducting shell are in surface free contact connection, and contact surfaces are pressed through a prepressing bending moment to ensure bonding; The support column is a rectangular column with clamping grooves on four sides and is positioned in the center of the lower surface plate, the lower surface of the support column is fixedly connected with the upper surface of the lower surface plate, the upper surface of the support column is in free contact connection with the lower surface of the upper surface plate, the bimetallic strip is four curved beams which are made of bimetal flat plates in a stamping mode, the curved beam body is in a circular arc shape, each curved beam is divided into two sections, a straight extension section without any curvature is additionally processed on two sides of each curved beam, a first section of the curved beam is a complete circular arc stamping curved beam with an extension section, the extension section of one end of the curved beam is connected with a clamping groove clamping tenon of the upper heat conducting column, the other end of the curved beam is connected with a clamping groove clamping tenon of the metal connecting block, and a second section of the curved beam is a semicircular arc stamping curved beam with an extension section, one end of the curved beam is connected with the clamping groove clamping tenon of the metal connecting block, and the other end of the curved beam is connected with the clamping tenon of the support column.
2. The heat dissipation-insulation switchable passive thermal intelligent structure according to claim 1, wherein the surface plates and the support columns are made of 304 stainless steel materials with low heat conduction, the heat conduction shell is made of 1070 aluminum alloy materials with high heat conduction, the bimetallic strip is 5J39110 bimetallic strip, and the high expansion layer is Mn72Ni10Cu18 alloy.
3. The heat dissipation-insulation switchable passive thermal intelligent structure according to claim 1, wherein the curvature radius of the curved beam is not less than half of the arc span, and can be equivalent to a central angle of not more than 180 °.
4. A switchable heat dissipating-insulating passive thermal intelligent structure according to claim 2, wherein said thermally conductive housing material is replaced by a T2 copper alloy from 1070 aluminum alloy.
5. The heat radiation-heat insulation switchable passive thermal intelligent structure according to claim 1, wherein the support columns and the lower surface plates are integrally formed by machining, the contact surfaces of the upper surface plates and the upper heat conduction columns and the contact surfaces of the lower surface plates and the lower heat conduction columns are connected through bolts by tapping, and heat conduction glue is smeared at the interface.
6. The heat dissipation-insulation switchable passive thermal intelligent structure according to claim 1, wherein the surface of the thermal intelligent structure is polished smoothly and coated with a coating for reducing heat radiation.

Description

Heat dissipation-heat insulation switchable passive thermal intelligent structure Technical Field The invention belongs to the field of heat protection of spacecrafts, and particularly relates to a heat dissipation-heat insulation switchable passive heat intelligent structure. Background With the continuous development of the aerospace technology, the equipment carried by the spacecraft is miniaturized and integrated, and the facing working environment is complicated. When high-intensity heat flow impact such as high-energy laser irradiation is faced, severe temperature gradient is easily formed in local areas, and material performance degradation and even structural failure are induced. In order to inhibit the temperature rise at the initial stage of thermal shock, the protection structure needs to have strong heat insulation capability, and in the long-time normal service stage without strong thermal shock, the protection structure must also be capable of effectively radiating heat to avoid the whole temperature runaway caused by internal heat accumulation, so that the intelligent thermal control structure is required to realize the intelligent switching of heat insulation and heat conduction states along with the change of external temperature. At present, the design of a protective structure aiming at a high heat flow environment depends on low heat conduction heat insulation materials or a multi-layer heat protection system to weaken the transmission of heat to an internal structure, and the scheme has a certain effect in the aspect of short-time thermal shock inhibition, but also can obviously reduce the heat dissipation capacity of the structure, and is easy to cause the problem of heat accumulation under repeated or long-time service conditions. Although the active thermal control structure can realize accurate regulation and control of heat flow, the active thermal control structure has certain limitation on long-term reliability due to the need of external energy supply. For example, the patent 'method for forming a thermal switch' (CN 109312975B) proposes an air gap type active thermal switch control method based on material thermal expansion difference, and realizes high-efficiency regulation and control of on-off of heat flow in an extremely low temperature environment. However, the design only considers the working scene of extremely low temperature (5-20K), and needs additional air extraction and air supply devices, so that the system has high complexity and large volume, and the requirements of miniaturization and high stability of the aerospace equipment are met. The thermal intelligent material with the adjustable thermal conductivity coefficient is a material capable of automatically making corresponding changes of self thermal conductivity to external excitation, can realize adjustment among different thermal conductivity states without external energy input, and plays an important role in a spacecraft thermal management system under a complex thermal environment. According to different adjusting mechanisms, the thermal intelligent materials can be classified into external field driving type, phase change material type, structural reconfiguration type and the like. Typical external field driven thermally intelligent materials, such as ferroelectric materials, can cause domain inversion and rearrangement under strong electric fields, and adjust the thermal conductivity of the material by changing the phonon mean free path. The phase change material type thermal intelligent material realizes solid-liquid phase change or the mutation of heat conductivity coefficient through the transformation of different polymer conformations by a temperature field, for example, the reversible jump of 200% of heat conductivity coefficient can be realized through the switching between low-temperature diamagnetic phase and high-temperature paramagnetic phase of polymers such as hexagonal sulfides and the like. The structural reconstruction type thermal intelligent structure (mechanical metamaterial) is stretched or deformed by virtue of movable parts in the thermal intelligent structure, the heat transfer path is connected and disconnected by utilizing the lamination and separation of a physical contact surface, so that the thermal conductivity is greatly adjusted. The existing structural reconfiguration type thermal intelligent structure mainly comprises a micro-gap type, a shape memory alloy type, a paper folding structure, a bimetal type and the like. The micro gap type thermal intelligent structure is provided with a micro gap in a micron level, the gap is eliminated by utilizing the thermal expansion of the structure after being heated, and the structure is switched from a low heat conduction state to a high heat conduction state. For example, a patent 'double-drive space thermal switch for spacecraft based on phase change material and metal micro-expansion' (CN 111552327A) proposes a passive thermal sw