CN-122008676-A - Multi-element heat-blocking step heat insulation system

CN122008676ACN 122008676 ACN122008676 ACN 122008676ACN-122008676-A

Abstract

The invention discloses a multi-element heat-blocking step heat insulation system, and belongs to the technical field of heat protection. The system comprises a plurality of layers of heat insulation materials formed by alternately bonding aluminized polyimide films and spacing materials, wherein the uppermost layer and the lowermost layer are films, an intermediate layer hard heat insulation board is bonded to the lower surface of the lowermost layer film, an inner layer hard heat insulation board is arranged on the lowermost layer of the system, and a composite phase change material is filled between the intermediate layer and the inner layer hard heat insulation board. According to the multi-element heat blocking and cascade protection concept, the multi-layer heat insulation material is used for efficiently reflecting and blocking high-temperature radiation, two layers of hard heat insulation plates are used for providing structural support and blocking heat conduction, and the heat transfer is delayed by means of the phase change latent heat of the composite phase change material. The system integrates three mechanisms of radiation blocking, heat conduction blocking and heat absorption delay, has the advantages of strong heat insulation performance, small volume and weight, stable and reliable structure, and is suitable for thermal environment guarantee of the high-speed aircraft on-board test equipment cabin under the condition of long-time cruising in a nearby space.

Inventors

DING CHEN
YANG CHEN
LI MINGJIA
LI HUIYI
WANG KAINING
Teng Yuji

Assignees

北京理工大学

Dates

Publication Date: 20260512
Application Date: 20260409

Claims (10)

1. The multi-element heat-blocking stair heat insulation system is characterized by comprising a middle-layer hard heat insulation plate (3) and an inner-layer hard heat insulation plate (5), wherein a plurality of layers of heat insulation materials are adhered to the upper surface of the middle-layer hard heat insulation plate (3), each layer of heat insulation materials is formed by alternately adhering an aluminum-plated polyimide film (1) and a spacing material (2), the uppermost layer and the lowermost layer of each layer of heat insulation materials are all aluminum-plated polyimide films (1), and a composite phase change material (4) is filled between the middle-layer hard heat insulation plate (3) and the inner-layer hard heat insulation plate (5).
2. The multi-element heat-blocking stair thermal insulation system according to claim 1, wherein the multi-layer thermal insulation material is formed by alternately stacking and bonding at least two layers of aluminized polyimide films (1) and at least one layer of interlayer insulation material (2) in parallel.
3. The multi-element heat-blocking step heat insulation system according to claim 1 or 2, wherein the middle layer hard heat insulation plate (3) and the inner layer hard heat insulation plate (5) are inorganic fiber reinforced silica aerogel heat insulation plates and are arranged in parallel.
4. The multi-element heat blocking step insulation system of claim 3 wherein the inorganic fiber reinforced silica aerogel insulation panel has a density of 280 kg/m3, a tensile strength of greater than 1.5 MPa, and a thermal conductivity of 0.02W/m-K.
5. The multi-element heat-blocking step heat insulation system according to claim 1 or 2, wherein the substrate of the aluminized polyimide film (1) is a polyimide film, the metal film layer is aluminum, the thickness of the polyimide film is 2-20 μm, and the thickness of the metal aluminum film layer is 400-1200 a.
6. The multi-element heat-blocking step heat insulation system according to claim 1 or 2, wherein the spacer material (2) is glass fiber cloth, the aperture ratio is 0.6-0.8, the heat conductivity coefficient is 0.01W m-K, and the thickness is 1.5 mm-2.5 mm.
7. The multi-element heat-blocking step heat insulation system according to claim 1, wherein the composite phase change material (4) is formed by compounding 60% -80% by mass of paraffin and 20% -40% by mass of hydrophobic silica aerogel through a vacuum impregnation method.
8. The multi-element heat-blocking cascade heat insulation system according to claim 7, wherein the phase change latent heat of the composite phase change material (4) is 113.0 kJ/kg-150.8 kJ/kg, and the heat conductivity coefficient is 0.092W/m-K.
9. The multi-element heat-blocking cascade heat insulation system according to claim 7, wherein the paraffin wax has a phase transition temperature of 60.82 ℃ and latent heat of phase transition of 188.44 kJ/kg, the hydrophobic silica aerogel has a pore size of 20 nm, a porosity of more than 90% and a hydrophobicity of more than or equal to 99%.
10. The multi-element heat-blocking step heat insulation system according to claim 9, wherein the middle layer hard heat insulation plate (3) divides the whole system into a high temperature side and a low temperature side, wherein the high temperature side is the multi-layer heat insulation material, the low temperature side is the composite phase change material (4), and the inner layer hard heat insulation plate (5) is positioned at the innermost layer of the system.

Description

Multi-element heat-blocking step heat insulation system Technical Field The invention belongs to the technical field of heat protection, and particularly relates to a multi-element heat-blocking step heat insulation system. Background With the development of aerospace technology, high-speed aircrafts (such as hypersonic aircrafts) have become an important development direction to perform long-time cruising tasks in near space. When the aircraft flies at a high speed in the near space, the surface of the aircraft is severely compressed and rubbed with the lean atmosphere, and extremely high aerodynamic heating effect is generated, so that strong external heat flow is formed. This heat is transferred to the interior of the aircraft mainly by both thermal radiation and thermal conduction, resulting in a sharp rise in temperature within the body. The cabin of the airborne test equipment is internally provided with precise test instruments, sensors, cables and other equipment, the equipment has strict requirements on the working environment temperature, and the excessive cabin temperature can lead to the performance reduction, data distortion and even permanent damage of the equipment. Therefore, designing an efficient, reliable, and lightweight thermal protection system to ensure that the interior of the test equipment compartment is within a safe temperature range is one of the significant challenges faced by high-speed aircraft design. Conventional aircraft cabin interior thermal protection schemes often employ a single insulating material, such as aerogel blanket, inorganic fiber wool, or homogeneous insulation panels. The materials mainly rely on the low heat conduction characteristic to separate heat conduction, have relatively simple structure and have certain high temperature resistance. However, the traditional approach of relying solely on thermal conduction barriers appears to catch the forefront in the face of the sustained, high intensity, and significant component of the thermal load generated by long cruising in the near space. In order to achieve the required heat insulation effect, the thickness of the heat insulation layer is often required to be increased, which not only increases the volume and weight of the protection system obviously, but also may occupy valuable equipment installation space against the design principle of light weight and compactness of the aircraft structure. In the field of spacecraft thermal control, multilayer Insulation (MLI) is a mature passive thermal control technology. It is typically formed by alternating layers of high reflectivity film (e.g., aluminized polyimide film) with low thermal conductivity spacer material. The heat insulation principle is mainly based on high-efficiency blocking of radiation heat transfer, wherein each layer of reflecting film reflects most of incident heat radiation back, and radiation heat flow is greatly attenuated due to layer-by-layer reflection. MLI has particularly outstanding inhibition effect on radiation heat transfer in vacuum or low-pressure environment (such as space or near space). Aerogel materials, on the other hand, are known as "super insulating materials" because of their extremely low thermal conductivity (often lower than still air). Particularly, the silica aerogel thermal insulation board reinforced by inorganic fibers (such as quartz fibers and ceramic fibers) has excellent mechanical strength and dimensional stability while keeping extremely low heat conductivity, can resist vibration and impact in the flying process, and is suitable for being used as a structural bearing or dimensional component. The phase change material (PHASE CHANGE MATERIAL, PCM) provides a unique thermal protection mechanism based on latent heat absorption. PCM is capable of absorbing and storing a large amount of latent heat when undergoing a phase change (e.g., solid-liquid phase change), while its own temperature remains substantially constant during the phase change. The PCM is applied to a thermal protection system, so that the heat transfer process to a protected area can be effectively delayed, and valuable time is gained for coping with transient or continuous heat loads, which is particularly important for aircrafts requiring long-time cruising. However, conventional solid-liquid phase materials are prone to leakage and flow after melting, affecting system reliability and stability. The use of porous media (e.g., aerogel) to adsorb the phase change material to form a shaped composite phase change material is an effective way to solve this problem. In view of the above, it has been difficult to meet the demanding requirements of high efficiency, lightweight, long-term thermal protection for on-board equipment cabins of high-speed aircraft in the near space with a single type of thermal protection material or a single thermal barrier mechanism. Therefore, an innovative design of a thermal protection system is needed, which can comp