Heat-insulation fire-resistant cable

Abstract

The utility model discloses a heat insulation fireproof cable, which can enhance the high temperature resistance of the cable, enables the cable to have good mechanical performance and electrical performance, and facilitates the improvement of the safety and reliability of the cable. The heat-insulation fire-resistant cable comprises a wire core and a sheath. The wire core comprises a wire (1), a polytetrachloroethylene layer (3) and a crosslinked polyethylene insulating layer (2). The outer side of the wire (1) is coated with a polytetrachloroethylene layer (3). And the crosslinked polyethylene insulating layer (2) coats the outer side of the polytetrachloroethylene layer (3). The sheath comprises a basalt fiber layer (4), a zirconia aerogel layer (5) and a protective layer. And a basalt fiber layer (4) coats the outer side of the wire core. And the zirconium oxide aerogel layer (5) is coated on the outer side of the basalt fiber layer (4). And the protective layer is coated on the outer side of the zirconium oxide aerogel layer (5).

Description

Technical Field

[0001] The utility model belongs to the technical field of cables, and in particular relates to a heat-insulating and fire-resistant cable. Background Art

[0002] With the rapid development of the national power industry, the demand for power cables is increasing. State Grid and China Southern Grid have proposed to continuously optimize the grid layout and promote the coordinated development of the overall power industry and regional economy. At the same time, the country is also continuously promoting the realization of the "carbon peak" and "carbon neutrality" goals. As the main nerve of power transmission and transformation in the power system, the operating stability and environmental protection of B1 cable have once again been challenged.

[0003] Existing cables have relatively simple performance due to material problems and cannot take into account a variety of usage environments. In extreme environments (such as continuous exposure to a flame of 950℃~1000℃ for at least 90 minutes), the safety and reliability of the cables will still be affected, and their environmental protection performance is poor. Therefore, a cable with good heat insulation and high temperature resistance and environmental protection is needed. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a heat-insulating fire-resistant cable in view of the above-mentioned deficiencies in the prior art, which can enhance the high-temperature resistance of the cable, and make the cable have good mechanical and electrical properties, thereby improving the safety, reliability and environmental protection of the cable.

[0005] In a first aspect, an embodiment of the utility model provides a heat-insulating fire-resistant cable, the heat-insulating fire-resistant cable comprising a core and a sheath. The core comprises a conductor, a polytetrachloroethylene layer and a cross-linked polyethylene insulation layer. The polytetrachloroethylene layer is coated on the outside of the conductor. The cross-linked polyethylene insulation layer is coated on the outside of the polytetrachloroethylene layer. The sheath comprises a basalt fiber layer, a zirconia aerogel layer and a protective layer. The basalt fiber layer is coated on the outside of the core. The zirconia aerogel layer is coated on the outside of the basalt fiber layer. The protective layer is coated on the outside of the zirconia aerogel layer.

[0006] In some embodiments, the polytetrachloroethylene layer is formed on the outside of the conductor by a dry mixing process; and / or the cross-linked polyethylene insulation layer is formed on the outside of the polytetrachloroethylene layer by an extrusion process after high-temperature compounding; and / or the basalt fiber layer is formed on the outside of the wire core by a melt spinning process; and / or the zirconia aerogel layer is formed on the outside of the basalt fiber layer by a sol-gel process.

[0007] In some embodiments, the wire core further includes a conductor shielding layer, and the conductor shielding layer is coated on the outside of the wire; the polytetrachloroethylene layer is coated on the outside of the conductor shielding layer.

[0008] In some embodiments, the wire core further includes an insulating shielding layer, and the insulating shielding layer is coated on the outside of the cross-linked polyethylene insulating layer.

[0009] In some embodiments, the heat-insulated fire-resistant cable further comprises a filling layer, wherein the filling layer is arranged between the insulating shielding layer and the basalt fiber layer.

[0010] In some embodiments, the protective layer includes a flame retardant polyolefin layer, and the flame retardant polyolefin layer is coated on the outside of the zirconia aerogel layer.

[0011] In some embodiments, the flame retardant polyolefin layer is formed on the outer side of the zirconia aerogel layer by an extrusion process.

[0012] In some embodiments, the protective layer further comprises an inner sheath layer and an outer sheath layer, wherein the inner sheath layer is coated on the outer side of the flame retardant polyolefin layer, and the outer sheath layer is coated on the outer side of the inner sheath layer.

[0013] In some embodiments, the protective layer further comprises an armor layer, wherein the armor layer is coated on the outer side of the inner sheath layer, and the outer sheath layer is coated on the outer side of the armor layer.

[0014] In some embodiments, the number of the wire cores is multiple, and the basalt fiber layer in the sheath is coated on the outside of all the wire cores.

[0015] Therefore, in the heat-insulating fire-resistant cable provided by the embodiment of the utility model, the core includes a conductor, a polytetrachloroethylene layer and a cross-linked polyethylene insulation layer, and the sheath includes a basalt fiber layer, a zirconia aerogel layer and a protective layer, wherein the polytetrachloroethylene layer, the cross-linked polyethylene insulation layer, the basalt fiber layer and the zirconia aerogel layer all have good high temperature resistance, which can enhance the high temperature resistance of the cable, so that the cable can still maintain stable electrical and mechanical properties in a high temperature environment (continuously exposed to a flame of 950°C to 1000°C for at least 90 minutes), ensuring the safe use of the cable under extreme conditions. The zirconia aerogel layer can also effectively reduce external heat transfer, protect the wires inside the cable from high temperature damage, and further enhance the fire resistance of the cable. The polytetrachloroethylene layer, the cross-linked polyethylene insulation layer, and the basalt fiber layer all have good insulation properties, which can effectively prevent current leakage and short circuit, and improve the safety and reliability of the cable. Both the polytetrachloroethylene layer and the zirconia aerogel layer have high chemical stability, can resist chemical corrosion, and extend the service life of the cable; the production process of the basalt fiber layer and the zirconia aerogel layer has little pollution and little waste, and meets environmental protection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1: A schematic diagram of a heat-insulating fire-resistant cable provided in an embodiment of the utility model;

[0017] Figure 2 : A cross-sectional view of a heat-insulating and fire-resistant cable provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0019] Embodiment 1:

[0020] like Figure 1 and Figure 2 As shown, an embodiment of the utility model provides a heat-insulating fire-resistant cable, which belongs to a Class B1 cable. The heat-insulating fire-resistant cable includes a core and a sheath. The core includes a conductor 1, a polytetrachloroethylene layer 3 and a cross-linked polyethylene insulation layer 2. The polytetrachloroethylene layer 3 is coated on the outside of the conductor 1. The cross-linked polyethylene insulation layer 2 is coated on the outside of the polytetrachloroethylene layer 3. The sheath includes a basalt fiber layer 4, a zirconia aerogel layer 5 and a protective layer. The basalt fiber layer 4 is coated on the outside of the core. The zirconia aerogel layer 5 is coated on the outside of the basalt fiber layer 4. The protective layer is coated on the outside of the zirconia aerogel layer 5.

[0021] The conductor 1 may be a copper conductor, an aluminum conductor, etc. The conductor 1 may be a single-strand conductor or a multi-strand conductor.

[0022] In some examples, the cross-linked polyethylene insulation layer 2 is compounded at high temperature and then formed on the outside of the polytetrachloroethylene layer 3 by an extrusion process.

[0023] The cross-linked polyethylene insulation layer 2 still has good mechanical and electrical properties at high temperatures, and after 60 days of heat aging at a temperature of 135°C, the mechanical and electrical properties of the cross-linked polyethylene insulation layer 2 can still remain excellent. It still has good insulation performance under high voltage (above 10kV) and ultra-high voltage (330kV to 750kV) conditions, and can effectively solve the problem of polarity reversal in cables.

[0024] In some examples, the polytetrachloroethylene layer 3 is formed on the outside of the conductive wire 1 by a dry mixing process.

[0025] The dry mixing production process is a process that prepares a specified product by drying and mixing different raw materials.

[0026] The polytetrachloroethylene layer 3 has excellent insulation performance, high temperature resistance and chemical stability, and can meet the use requirements in extreme environments; the polytetrachloroethylene layer 3 has a very wide operating temperature range, and the polytetrachloroethylene layer 3 can maintain stable performance from -200°C to 180°C, that is, whether in a high temperature or low temperature environment, the polytetrachloroethylene layer 3 in the cable can maintain its original electrical properties and mechanical strength, thereby ensuring the safe operation of the cable. The polytetrachloroethylene layer 3 has a very low friction coefficient and good self-lubricating properties, which makes the cable smoother during installation, maintenance and use, reducing friction loss and energy loss. The polytetrachloroethylene layer 3 can make the cable have excellent electrical properties, such as high insulation strength, low resistivity and low dielectric constant, etc., which ensures the efficiency and safety of the cable when transmitting electric energy, and reduces power loss and failure risks. The polytetrachloroethylene layer 3 also has good processing performance and environmental protection performance.

[0027] In some examples, the basalt fiber layer 4 is formed on the outside of the wire core by a melt spinning process.

[0028] The melt spinning process is a forming method that uses polymer melt as raw material and adopts a melt spinning machine for spinning.

[0029] The basalt fiber layer 4 not only has the advantages of high strength and high corrosion resistance, but also has good insulation performance, and the production process of the basalt fiber layer 4 has little pollution and less waste. The continuity and uniformity of the basalt fiber help maintain the overall strength of the cable and prevent the overall failure of the cable caused by local damage. The basalt fiber layer 4 is melt-drawn at a high temperature of 1450℃ to 1500℃, so it has excellent high temperature resistance. Therefore, in a high temperature environment, the basalt fiber layer 4 can enable the cable to maintain stable electrical performance and mechanical strength, making the cable suitable for high temperature working environments and various power transmission systems.

[0030] The basalt fiber layer 4 is mainly composed of inorganic substances such as silicate, so when the cable is used in an environment containing corrosive substances such as acid and alkali, it can effectively prevent the corrosion and aging of the cable and extend the service life of the cable. Basalt fiber is a new type of inorganic environmentally friendly green high-performance fiber material. It can be biodegraded in the environment after being discarded and is harmless to the environment.

[0031] In some examples, the zirconia aerogel layer 5 is formed on the outer side of the basalt fiber layer 4 by a sol-gel process.

[0032] Zirconia aerogel material has a low thermal conductivity (0.01W / m·K~0.02W / m·K), making it an efficient thermal insulation material, so the zirconia aerogel layer 5 can effectively reduce heat transfer and protect the wire 1 inside the cable from external high temperature damage; the zirconia aerogel material also has a high specific surface area (100m2 / g-675.6m2 / g) and a small particle size (<10nm), which makes it have nano-scale structural controllability and improves the thermal insulation performance of the zirconia aerogel layer 5; the zirconia aerogel material has a low density (30Kg / m3~150Kg / m3) and a high porosity (85%~99%), which further enhances the thermal insulation effect of the zirconia aerogel layer 5. The zirconia aerogel layer 5 has a low resistance at high temperature and a high resistance at low temperature, and has high chemical stability and thermal stability, so that the cable can adapt to various complex environments. The preparation and use of the zirconia aerogel layer 5 does not generate pollution, which is in line with the current development trend of green environmental protection.

[0033] The protective layer can protect the various layers of structure inside it to prevent the various layers of structure inside it from being damaged by external forces.

[0034] Thus, in the heat-insulating fire-resistant cable provided by the embodiment of the utility model, the core includes a conductor 1, a polytetrachloroethylene layer 3 and a cross-linked polyethylene insulation layer 2, and the sheath includes a basalt fiber layer 4, a zirconia aerogel layer 5 and a protective layer, wherein the polytetrachloroethylene layer 3, the cross-linked polyethylene insulation layer 2, the basalt fiber layer 4 and the zirconia aerogel layer 5 all have good high temperature resistance, which can enhance the high temperature resistance of the cable, so that the cable can still maintain stable electrical and mechanical properties in a high temperature environment (continuously exposed to a flame of 950°C to 1000°C for at least 90 minutes), ensuring the safe use of the cable under extreme conditions. The zirconia aerogel layer 5 can also effectively reduce external heat transfer, protect the conductor 1 inside the cable from high temperature damage, and further enhance the fire resistance of the cable. The polytetrachloroethylene layer 3, the cross-linked polyethylene insulation layer 2, and the basalt fiber layer 4 all have good insulation properties, which can effectively prevent current leakage and short circuit, and improve the safety and reliability of the cable. The polytetrachloroethylene layer 3 and the zirconium oxide aerogel layer 5 both have high chemical stability, can resist chemical corrosion, and extend the service life of the cable; the production process of the basalt fiber layer 4 and the zirconium oxide aerogel layer 5 has little pollution and little waste, and meets environmental protection requirements.

[0035] In some embodiments, Figure 1 and Figure 2 As shown, the wire core further comprises a conductor shielding layer 7, and the conductor shielding layer 7 is coated on the outside of the wire 1. The polytetrachloroethylene layer 3 is coated on the outside of the conductor shielding layer 7.

[0036] Exemplarily, the material of the conductor shielding layer 7 is a cross-linked semi-conductive shielding material. For example, the material of the conductor shielding layer 7 may include polyethylene, an antioxidant, a cross-linking agent, and the like.

[0037] like Figure 2 As shown, the conductor shielding layer 7 can shield the electric field generated by the conductor 1 inside it and prevent the material of the polytetrachloroethylene layer 3 from squeezing into the gap of the conductor 1 when the polytetrachloroethylene layer 3 is manufactured, thereby reducing the electric field concentration of the cable and improving the insulation performance of the cable, thereby improving the electrical performance of the cable in a high-voltage environment.

[0038] In some embodiments, Figure 1 and Figure 2 As shown, the wire core further includes an insulating shielding layer 8 , which is coated on the outside of the cross-linked polyethylene insulating layer 2 .

[0039] Exemplarily, the material of the insulating shielding layer 8 is a cross-linked semi-conductive shielding material. For example, the material of the insulating shielding layer 8 may include polyethylene, an antioxidant, a cross-linking agent, and the like.

[0040] Similarly, the insulating shielding layer 8 can further reduce the electric field concentration of the cable and improve the insulation performance of the cable, thereby improving the electrical performance of the cable in a high voltage environment.

[0041] In some embodiments, Figure 1 and Figure 2 As shown, the heat-insulated fire-resistant cable further comprises a filling layer 12. The filling layer 12 is arranged between the insulating shielding layer 8 and the basalt fiber layer 4.

[0042] Exemplarily, the filling layer 12 may be formed of polypropylene rope, high temperature rock wool rope or basalt fiber rope.

[0043] The filling layer 12 can fill the gap between the core and the sheath, fix the core, buffer the extrusion force when the cable is subjected to external extrusion force, and improve the compression resistance of the cable. The filling layer 12 can also further improve the moisture-proof and heat-insulating capabilities of the cable and improve the roundness of the cable.

[0044] In some embodiments, Figure 1 and Figure 2 As shown, the protective layer includes a flame retardant polyolefin layer 6 , and the flame retardant polyolefin layer 6 is coated on the outside of the zirconium oxide aerogel layer 5 .

[0045] As a thermoplastic material, polyolefin material has good processing properties. This material can be processed at a lower temperature, which reduces the production cost of the flame retardant polyolefin layer 6 and improves production efficiency, making the flame retardant polyolefin layer 6 suitable for various environments and applications, especially in harsh environments such as humidity, high temperature, flammable and explosive.

[0046] The flame retardant polyolefin layer 6 is formed on the outer side of the zirconia aerogel layer 5 by an extrusion process.

[0047] The flame retardant polyolefin layer 6 formed by the extrusion process has the characteristics of relatively small molecular structure density and high mechanical strength, so that the flame retardant polyolefin layer 6 not only protects the internal structure of the cable, but also has strong tensile, compressive and impact resistance, as well as good waterproof and insulating properties, which can effectively prevent water and moisture from corroding the cable and improve the service life and safety of the cable.

[0048] In some embodiments, Figure 1 and Figure 2 As shown, the protective layer further comprises an inner sheath layer 9 and an outer sheath layer 11. The inner sheath layer 9 is coated on the outer side of the flame retardant polyolefin layer 6. The outer sheath layer 11 is coated on the outer side of the inner sheath layer 9.

[0049] For example, the material of the inner sheath layer 9 may be polyvinyl chloride, polyethylene or polyolefin, etc. The material of the outer sheath layer 11 may be polyvinyl chloride, polyethylene or polyolefin, etc.

[0050] The inner sheath layer 9 and the outer sheath layer 11 are used to enhance the mechanical strength of the cable, especially in applications where it is necessary to resist external mechanical impact or protect the cable from damage by underground animals, to improve the various properties of the cable and to protect its internal structure.

[0051] In some embodiments, Figure 1 and Figure 2 As shown, the protective layer further includes an armor layer 10, which is coated on the outside of the inner sheath layer 9. An outer sheath layer 11 is coated on the outside of the armor layer 10.

[0052] Exemplarily, the armor layer 10 may be formed by wrapping galvanized steel strip, stainless steel strip (non-magnetic), galvanized steel wire, aluminum strip or aluminum alloy strip.

[0053] The armor layer 10 can increase the radial force that the cable can withstand, protect the structural integrity and electrical performance of the cable, and increase the service life of the cable.

[0054] In some embodiments, Figure 1 and Figure 2 As shown, there are multiple cores. The basalt fiber layer 4 in the sheath is coated on the outside of all the cores.

[0055] For example, the number of the cores may be two, three, four, etc.

[0056] By providing multiple cores, the ability of the cable to transmit electrical energy can be improved, and the cost of using the cable can be reduced.

[0057] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A heat-insulating fire-resistant cable, characterized in that: Including wire core and sheath; The wire core comprises: Wire (1); a polytetrachloroethylene layer (3) covering the outer side of the wire (1); and, A cross-linked polyethylene insulation layer (2) coated on the outside of the polytetrachloroethylene layer (3); The sheath comprises: A basalt fiber layer (4) is coated on the outside of the wire core; a zirconia aerogel layer (5), coated on the outside of the basalt fiber layer (4); and, A protective layer is coated on the outer side of the zirconia aerogel layer (5).

2. The heat-insulated fire-resistant cable according to claim 1, characterized in that: The polytetrachloroethylene layer (3) is formed on the outer side of the conductor (1) by a dry mixing process; and / or, The cross-linked polyethylene insulation layer (2) is compounded at high temperature and then formed on the outer side of the polytetrachloroethylene layer (3) by an extrusion process; and / or, The basalt fiber layer (4) is formed on the outer side of the core by a melt spinning process; and / or, The zirconium oxide aerogel layer (5) is formed on the outer side of the basalt fiber layer (4) by a sol-gel process.

3. The heat-insulated fire-resistant cable according to claim 1, characterized in that: The wire core further comprises a conductor shielding layer (7), wherein the conductor shielding layer (7) is coated on the outside of the wire (1); The polytetrachloroethylene layer (3) is coated on the outside of the conductor shielding layer (7).

4. The heat-insulated fire-resistant cable according to claim 1, characterized in that: The wire core further comprises an insulating shielding layer (8), wherein the insulating shielding layer (8) is coated on the outside of the cross-linked polyethylene insulating layer (2).

5. The heat-insulated fire-resistant cable according to claim 4, characterized in that: Also includes a filling layer (12); The filling layer (12) is arranged between the insulating shielding layer (8) and the basalt fiber layer (4).

6. The heat-insulated fire-resistant cable according to claim 1, characterized in that: The protective layer comprises a flame retardant polyolefin layer (6), and the flame retardant polyolefin layer (6) is coated on the outside of the zirconium oxide aerogel layer (5).

7. The heat-insulated fire-resistant cable according to claim 6, characterized in that: The flame-retardant polyolefin layer (6) is formed on the outer side of the zirconia aerogel layer (5) by an extrusion process.

8. The heat-insulated fire-resistant cable according to claim 6, characterized in that: The protective layer also includes: an inner sheath layer (9) covering the outer side of the flame retardant polyolefin layer (6); and, The outer sheath layer (11) is coated on the outer side of the inner sheath layer (9).

9. The heat-insulated fire-resistant cable according to claim 8, characterized in that: The protective layer further comprises an armor layer (10), wherein the armor layer (10) is coated on the outer side of the inner sheath layer (9); The outer sheath layer (11) is coated on the outside of the armor layer (10).

10. The heat-insulated fire-resistant cable according to claim 1, characterized in that: The number of the wire cores is multiple; The basalt fiber layer (4) in the sheath is coated on the outside of all the wire cores.

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