CN-122025259-A - High-temperature-resistant sensor cable insulated by aerogel

Abstract

The invention relates to the technical field of high-temperature-resistant cables, in particular to a high-temperature-resistant sensor cable insulated by aerogel. The cable comprises a conductor core wire, a composite insulating layer, a metal shielding layer, a heat insulating layer and an outer sheath from inside to outside in sequence along the radial direction, wherein the heat insulating layer is a continuous coating structure formed by low-heat-conduction nano porous materials, preferably silica aerogel, and is tightly attached to the metal shielding layer to form an interface thermal resistance layer. The metal shielding layer and the heat insulating layer form a composite heat resistance structure in a cooperative manner, and can reflect external heat radiation and inhibit solid conduction and gas convection heat transfer, so that heat resistance gradient distribution is formed in the radial direction of the cable, and the transmission of external high temperature to an internal conductor area is effectively reduced. The cable has the advantages of excellent heat insulation performance, compact structure, high reliability and the like, and is suitable for sensing signal transmission in aerospace, nuclear energy and high-temperature industrial environments.

Inventors

• WANG YULONG
• Cheng Boxuan
• GAO MINGYAN
• Cheng Xianshen
• LI LILI

Assignees

• 哈尔滨理工大学

Dates

Publication Date

20260512

Application Date

20260413

Claims (10)

1. 1. A high temperature resistant sensor cable is characterized in that, The cable comprises a conductor core wire, a composite insulating layer, a metal shielding layer, a heat insulating layer and an outer sheath from inside to outside in sequence along the radial direction, Wherein: the heat insulation layer is arranged between the metal shielding layer and the outer sheath, The heat insulation layer is a continuous coating structure formed by low-heat-conductivity nano porous materials, and is tightly attached to the metal shielding layer to form an interface thermal resistance layer; and: The metal shielding layer and the heat insulation layer cooperate to form a composite heat resistance structure, and the interface heat resistance layer participates in forming the heat resistance gradient distribution structure; the metal shielding layer is used for reflecting external heat radiation, and the heat insulation layer is used for inhibiting solid conduction and gas convection heat transfer, so that a non-uniform thermal resistance gradient distribution structure is formed in the radial direction of the cable; Such that: under the action of an external high-temperature environment, the cable forms a temperature gradient gradually decreasing from outside to inside along the radial direction, and the temperature of the conductor core wire is lower than the set safety temperature.
2. 2. The cable of claim 1, wherein the cable comprises a plurality of conductors, The low thermal conductivity nanoporous material comprises an aerogel or aerogel-based composite, preferably silica aerogel.
3. 3. The cable of claim 1, wherein the cable comprises a plurality of conductors, The heat conductivity coefficient of the heat insulation layer is not more than 0.03W/(m.K), the thickness of the heat insulation layer is 2-6 mm, So that the composite thermal resistance structure exhibits a decreasing thermal resistance gain characteristic when the thickness is increased beyond 3mm a.
4. 4. The cable of claim 1, wherein the cable comprises a plurality of conductors, The heat insulation layer is of a flexible felt-like structure, a sleeve structure or a wrapping structure, and forms a continuous wrapping structure so as to avoid forming an obvious air convection channel.
5. 5. The cable of claim 1, wherein the cable comprises a plurality of conductors, And a close contact interface is formed between the heat insulation layer and the metal shielding layer in a compaction or bonding mode, so that the heat transfer resistance at the interface is higher than that of the adjacent material layer.
6. 6. The cable of claim 1, wherein the cable comprises a plurality of conductors, The conductor core wire is a high-temperature-resistant metal conductor with an oxidation-resistant protective layer, and the oxidation-resistant protective layer comprises a nickel plating layer, a chromium plating layer or an alloy coating.
7. 7. The cable of claim 1, wherein the cable comprises a plurality of conductors, The composite insulating layer is of a multi-layer structure and comprises two or more layers of polytetrafluoroethylene layers, polyimide layers and fluorine polymer layers.
8. 8. The cable of claim 1, wherein the cable comprises a plurality of conductors, The metal shielding layer is of a metal braiding structure or a metal wrapping structure and has a reflecting effect on heat radiation so as to reduce radiation heat input to the heat insulation layer.
9. 9. The cable of claim 1, wherein the cable comprises a plurality of conductors, The outer sheath is a high-temperature-resistant metal sheath and forms an outer thermal shock buffering structure together with the heat insulation layer.
10. 10. The cable of claim 1, wherein the cable comprises a plurality of conductors, The conductor core wire temperature is lower than 200 ℃ when operating in an environment where the external temperature is not lower than 800 ℃.

Description

High-temperature-resistant sensor cable insulated by aerogel Technical Field The invention relates to the technical field of high-temperature resistant cables and high-temperature sensing, in particular to a high-temperature resistant sensor cable insulated by aerogel. Background In the fields of aerospace engine monitoring, nuclear reactor internal state detection, steel smelting process control, high-temperature chemical reaction devices and the like, various types of sensors such as temperature, pressure, strain and the like are generally required to be arranged in an extremely high-temperature environment. Signals collected by the sensors are required to be stably transmitted to an external control system through cables, so that the real-time monitoring and regulation of the running state of the equipment are realized. Therefore, the sensor cable is required to have not only good electrical conductivity and electrical insulation properties but also structural stability and reliability in a high temperature environment for a long period of time. In practical applications, the above working conditions are often accompanied by high temperature environments that continuously or instantaneously reach 800 ℃ or even above 1000 ℃. Under such extreme conditions, conventional cables are prone to thermal decomposition or melting of insulating materials, oxidation of conductors, increased resistance, and signal attenuation, thereby causing signal distortion, interruption, and even system operation failure. Therefore, how to effectively inhibit the transmission of external high temperature to the inside of the cable and keep the conductor and the insulation structure within the safe temperature range becomes a key technical problem to be solved in the technical field. In view of the above needs, various high temperature resistant cable structures have been proposed in the prior art, and mainly include the following schemes: the scheme adopts mineral materials such as magnesium oxide and the like as an insulating layer and is matched with a metal sheath to realize high-temperature protection. Although the cable has higher upper temperature resistance limit, the heat insulation of the cable mainly depends on the heat capacity of the material and the heat reflection capacity to a certain extent. Under high temperature environment, the metal sheath is easy to form a continuous heat conduction path, and external heat is transferred to the inside, so that the temperature inside the cable is still higher, and effective cooling is difficult to realize. In addition, the cable has the advantages of high structural rigidity, heavy weight and poor bending performance, and is not beneficial to installation and wiring in a complex space environment. The other type is a ceramic fiber or aluminum silicate fiber heat insulation structure, and the heat conductivity is reduced by arranging fiber materials on the outer layer of the cable and utilizing the porous structure of the fiber materials. The scheme can reduce heat conduction to a certain extent, but has the defects that on one hand, fiber materials are easy to be pulverized or embrittled under the action of long-term high temperature to cause gradual attenuation of heat insulation performance, and on the other hand, in order to achieve the expected heat insulation effect, the thickness of the materials is generally required to be increased, so that the overall size of the cable is increased, and the flexibility and engineering adaptability of the cable are affected. Meanwhile, the effective heat conductivity coefficient of the material in a high-temperature environment is relatively high, and the temperature control requirement under extreme working conditions is difficult to meet. A further category is a multi-layer composite heat insulation structure, which is formed by alternately stacking metal foils and low heat conduction materials, so as to realize heat insulation by utilizing heat radiation reflection and multiple thermal resistances. Although the scheme can improve the heat insulation performance to a certain extent, the structure is complex, the processing technology is high in requirement, and the manufacturing cost is high. Meanwhile, under a high-temperature environment, the metal foil is easy to oxidize or fail, and the interlayer structure can generate an unstable phenomenon due to thermal circulation, so that the overall heat insulation effect and the service life are affected. In summary, the existing high-temperature-resistant cable heat insulation technology generally has the following problems that the heat insulation efficiency is limited, the internal temperature of a cable is difficult to effectively reduce under an extremely high-temperature environment, the stability of a heat insulation structure is insufficient, performance attenuation easily occurs in a long-term use process, and the structure is complex or the size is large, so that the requirements