High temperature resistant, corrosion resistant and fireproof control cable for nuclear power plant

Abstract

The utility model discloses a kind of high-temperature-resistant corrosion-resistant fireproof control cables for nuclear power plant, including cable core, cable core is stranded by multiple insulated wire core, and light low-smoke halogen-free high flame-retardant filling rope is filled at the clearance of cable core;Cable core is covered with polyimide film belt, shielding layer in turn, shielding layer includes inner shielding layer, outer shielding layer, and inner shielding layer is overlapped with aluminium-plastic composite belt and wrapped, and aluminium surface is inward, and outer shielding layer is knitted with cornell nickel alloy wire;Shielding layer is covered with protective coating, the protective coating is extruded with sheath, and the sheath includes inner and outer double-layer structure, and inner sheath is extruded with polyether ether ketone material, and outer sheath is extruded with flame-retardant lead boron polyethylene material, and sheath surface is sprayed with polytetrafluoroethylene nano coating.The cable has excellent radiation resistance, high-temperature resistance, chemical corrosion resistance, fire resistance, electromagnetic interference resistance and other characteristics.

Description

Technical Field

[0001] This utility model relates to the field of power cables, specifically to a high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants. Background Technology

[0002] The construction of nuclear power plants is inseparable from cable connections. Among them, control cables play a crucial role in nuclear power plants, mainly used for power supply and signal control, interlocking and monitoring of instruments and control devices.

[0003] Due to the special environment in which nuclear power plants operate, control cables are required to possess characteristics such as radiation resistance, high temperature resistance, chemical corrosion resistance, fire resistance, and electromagnetic interference resistance. However, the fireproof layer of existing cables mainly consists of conductors wrapped with mica tape, insulation mainly consists of cross-linked polyethylene, and sheath mainly consists of thermoplastic polyolefin. Their radiation resistance is weak, and their electrical insulation performance is greatly reduced under long-term radiation. Their temperature resistance is only 90℃, making them unable to work normally in high-temperature environments for extended periods. Their chemical corrosion resistance is also poor, failing to maintain electrical performance and mechanical strength over a long period. Their fire resistance is insufficient, making it impossible to maintain electrical continuity for extended periods in the event of a fire. Furthermore, their electromagnetic interference resistance is not outstanding, leading to interference with line transmission.

[0004] For the reasons mentioned above, it is necessary to develop a high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants. Utility Model Content

[0005] In order to solve the problems existing in the prior art, this utility model provides a high-temperature resistant, corrosion-resistant and fireproof control cable for nuclear power plants. This cable has excellent characteristics such as radiation resistance, high temperature resistance, chemical corrosion resistance, fire resistance and electromagnetic interference resistance.

[0006] To achieve the above objectives, this utility model provides a high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants, comprising a cable core. The cable core is composed of multiple insulated cores twisted together in a 1+6 arrangement, with lightweight, low-smoke, halogen-free, and highly flame-retardant filler rope filling the gaps in the cable core. The cable core is sequentially covered with a polyimide film tape and a shielding layer. The shielding layer includes an inner shielding layer and an outer shielding layer. The inner shielding layer is made of aluminum-plastic composite tape with a thickness of 0.08-0.12mm and a width of 50-100mm, wrapped in an overlapping manner. Facing inward, the overlap rate is 15%-25%. The outer shielding layer is woven from Inconel nickel alloy wire with a diameter of 0.05-0.1mm, with a weaving density of 80%-90% and a weaving angle of 50-60°. The shielding layer is covered with a protective coating, and the protective coating is extruded with a sheath. The sheath has an inner and outer double-layer structure. The inner sheath is extruded from polyetheretherketone material, and the outer sheath is extruded from flame-retardant lead-boron polyethylene material. The surface of the sheath is sprayed with a polytetrafluoroethylene nano-coating with a thickness of 45-50um.

[0007] Preferably, the insulated wire core includes a conductor, and an insulating layer is wrapped around the conductor. The insulating layer includes an inner insulating layer and an outer insulating layer. The inner insulating layer is formed by wrapping a PTFE film tape with a thickness of 0.15 mm, with a wrapping overlap rate of 15%-25%, a thickness of 0.15±0.01 mm, a width of 50-80 mm, and a tensile strength ≥30 MPa. The outer insulating layer is formed by extruding a fluorinated ethylene propylene copolymer with a thickness of 0.6-0.8 mm, an extrusion thickness of 0.6-0.8 mm, a melt index of 0.5-1.5 g / 10 min, and a density of 2.1-2.3 g / cm³.

[0008] Preferably, the conductor is made of nickel-plated copper wire twisted in a 1+6 arrangement, which meets the requirements of GB / T 3956 for the second type of circular twisted structure.

[0009] Preferably, the nickel-plated copper wire has a plating thickness of 5-10 μm, a copper wire diameter of 0.1-1.0 mm, and a stranding pitch of 100-200 mm.

[0010] Preferably, the protective coating comprises a lightweight anti-corrosion and insulating inner coating, an intumescent cable fire-resistant intermediate coating, and an organosilicon high-temperature resistant outer coating, applied sequentially from the inside to the outside onto the shielding layer.

[0011] Preferably, the lightweight anti-corrosion and insulating inner coating is uniformly coated with water-based epoxy lightweight anti-corrosion and insulating paint with a thickness of 1.0-1.2 mm.

[0012] Preferably, the intumescent cable fireproof intermediate coating is uniformly coated with polyurethane elastomer fireproof coating and has a thickness of 0.4-0.6 mm.

[0013] Preferably, the high-temperature resistant silicone outer coating is formed by uniformly coating with a high-temperature resistant silicone coating and has a thickness of 45-50 μm.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] 1. The conductor of this utility model is made of nickel-plated copper wire stranded in a 1+6 arrangement, which meets the requirements of GB / T 3956, Type 2 circular stranded structure. Firstly, the nickel-plated copper wire has excellent corrosion resistance and can remain stable for a long time in harsh environments. The nickel plating layer effectively prevents the copper wire from contacting air, moisture, and chemicals, thereby reducing conductor oxidation and corrosion. Simultaneously, the nickel plating layer enhances the conductor's wear resistance, scratch resistance, and mechanical strength, effectively improving quality problems such as wear and scratches that may occur during production and distribution.

[0016] Secondly, the conductor adopts the second type of circular stranded structure, which is regularly stranded in a 1+6 arrangement. Compared with the first type of solid conductor, the second type of stranded conductor can improve the flexibility of the cable and reduce the installation strength of the cable. Compared with the fifth type of soft copper conductor, the fifth type of soft copper conductor is prone to loosening, resulting in an irregular appearance and higher contact resistance. Moreover, the conductor wires are thinner and more prone to breakage. The broken copper wire ends can easily penetrate the insulation body and cause hidden dangers. The second type of stranded conductor can avoid the above defects.

[0017] 2. The gaps in the cable core of this utility model are filled with lightweight, low-smoke, halogen-free, and highly flame-retardant filler rope. It not only has good flame-retardant properties, low smoke and halogen-free properties, and is non-toxic and environmentally friendly, but also has the characteristics of being lightweight, elastic, soft, and smooth. This allows the gaps in the cable core to be filled more densely and roundly. When the cable is exposed to flames, it can prevent the "chimney effect" from forming in the middle of the cable core, effectively improving the flame-retardant and fire-resistant performance of the cable.

[0018] 3. The double-layer shielding structure of this utility model effectively enhances the electromagnetic interference resistance of the cable. The inner shielding uses aluminum-plastic composite tape wrapped in an overlapping manner, which is lighter and cheaper than copper shielding and can reflect high-frequency electromagnetic interference. The outer shielding uses Inconel nickel alloy wire braiding, which has the characteristics of high temperature resistance, high corrosion resistance and high strength. It not only performs well in electromagnetic shielding, but also further improves the corrosion resistance and mechanical properties of the cable.

[0019] 4. The protective coating of this utility model is a multi-functional composite structure that integrates corrosion prevention, fire prevention, and high temperature resistance. Through the precise division of functions of "lightweight corrosion prevention - elastic fire prevention - high temperature resistance", it takes into account the safety, flexibility and environmental adaptability of the cable, and is especially suitable for scenarios with strict requirements for fire prevention, corrosion prevention and weight. Compared with traditional single fireproof coating, the three-layer composite design significantly improves the reliability and service life of the cable in complex environments.

[0020] 5. The sheath adopts a double-layer structure, which can effectively improve the overall performance of the cable, such as radiation resistance and corrosion resistance, and extend the service life of the cable.

[0021] 6. Spraying a polytetrafluoroethylene nano-coating onto the sheath surface can further enhance the cable's resistance to corrosion, water, and stains. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model;

[0023] Figure 2 This is a schematic diagram of the structure of the protective coating of this utility model. Detailed Implementation

[0024] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are only for illustrating the present invention and are not intended to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.

[0025] like Figure 1-2 As shown, this utility model provides a high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants, including an insulated core. The insulated core includes a conductor 1, and an insulation layer is wrapped around the conductor. The insulation layer includes a double-layer structure of an inner insulation layer 2 and an outer insulation layer 3. The inner insulation layer is made of a PTFE film tape with a thickness of 0.15mm, with a wrapping overlap rate of 15%-25%, a thickness of 0.15±0.01mm, a width of 50-80mm, and a tensile strength ≥30MPa. It has the characteristics of high and low temperature resistance (applicable temperature range -180℃ to +260℃), corrosion resistance, low friction, wear resistance, moisture resistance, and high insulation. It not only improves the high temperature resistance and corrosion resistance of the cable, but also prevents conductor burrs from affecting the outer insulation layer.

[0026] The outer insulation layer is extruded from fluorinated ethylene propylene copolymer with a thickness of 0.6-0.8 mm. The extrusion thickness is 0.6-0.8 mm, the melt index is 0.5-1.5 g / 10 min, and the density is 2.1-2.3 g / cm³. It has excellent electrical insulation properties, high and low temperature resistance (long-term allowable operating temperature range -85℃ to +200℃), chemical stability, and mechanical properties, which further improves the cable's high temperature resistance and corrosion resistance. At the same time, this material is non-flammable and can prevent the spread of flames, thus improving the cable's flame retardant properties.

[0027] Conductor 1 is made of nickel-plated copper wire stranded in a 1+6 arrangement, which meets the requirements of GB / T 3956 for the second type of circular stranded structure; the nickel plating thickness of the nickel-plated copper wire is 5-10μm, the diameter of the copper wire is 0.1-1.0mm, and the stranding pitch is 100-200mm.

[0028] It should be noted that: Firstly, nickel-plated copper wire has excellent corrosion resistance and can remain stable for a long time in harsh environments; the nickel plating layer effectively prevents the copper wire from contacting air, moisture, chemicals, etc., thereby reducing conductor oxidation and corrosion. At the same time, the nickel plating layer enhances the conductor's wear resistance, scratch resistance, and mechanical strength, effectively improving quality problems such as wear and scratches that may occur during production and distribution.

[0029] Secondly, the conductor adopts the second type of circular stranded structure, which is regularly stranded in a 1+6 arrangement. Compared with the first type of solid conductor, the second type of stranded conductor can improve the flexibility of the cable and reduce the installation strength of the cable. Compared with the fifth type of soft copper conductor, the fifth type of soft copper conductor is prone to loosening, resulting in an irregular appearance and higher contact resistance. Moreover, the conductor wires are thinner and more prone to breakage. The broken copper wire ends can easily penetrate the insulation body and cause hidden dangers. The second type of stranded conductor can avoid the above defects.

[0030] Multiple insulated wire cores are twisted together in a 1+6 arrangement to form the cable core. Lightweight, low-smoke, halogen-free, and highly flame-retardant filler rope 4 is filled in the gaps of the cable core. It not only has good flame-retardant properties, low smoke, halogen-free, non-toxic and environmentally friendly properties, but also has the characteristics of being lightweight, elastic, soft and smooth. This allows the gaps in the cable core to be filled more densely and roundly. When the cable is exposed to flames, it can avoid the "chimney effect" in the middle of the cable core, effectively improving the flame-retardant and fire-resistant performance of the cable.

[0031] The cable core is wrapped with a polyimide film tape 5, which gives the cable core excellent high and low temperature resistance, electrical insulation and radiation resistance. In addition to the function of wrapping and binding, it can also improve the radiation resistance of the cable.

[0032] The polyimide film tape 5 is covered with an outer shielding layer, including an inner shielding layer 6 and an outer shielding layer 7. The inner shielding layer is made of aluminum-plastic composite tape with a thickness of 0.08-0.12mm and a width of 50-100mm, with the aluminum side facing inward and an overlap rate of 15%-25%. The outer shielding layer is made of Inconel nickel alloy wire with a diameter of 0.05-0.1mm, with a weaving density of 80%-90% and a weaving angle of 50-60°.

[0033] It should be noted that the double-layer shielding structure effectively enhances the cable's electromagnetic interference resistance. The inner shield uses aluminum-plastic composite tape wrapped in an overlapping manner, which is lighter and cheaper than copper shielding and can reflect high-frequency electromagnetic interference. The outer shield uses Inconel nickel alloy wire braiding, which has the characteristics of high temperature resistance, high corrosion resistance, and high strength. It not only performs well in electromagnetic shielding, but also further improves the cable's corrosion resistance and mechanical properties.

[0034] Secondly, the outer protective coating 8 of the shielding layer is a multi-functional composite structure that integrates corrosion resistance, fire resistance, and high temperature resistance. Through the precise division of functions of "lightweight corrosion resistance - elastic fire resistance - high temperature resistance", it takes into account the safety, flexibility and environmental adaptability of the cable, and is especially suitable for scenarios with strict requirements for fire resistance, corrosion resistance and weight. Compared with the traditional single fireproof coating, the three-layer composite design significantly improves the reliability and service life of the cable in complex environments.

[0035] Finally, the protective coating is extruded onto a sheath. The sheath has a double-layer structure, with the inner sheath 9 made of polyetheretherketone material and the outer sheath 10 made of flame-retardant lead-boron polyethylene material. The surface of the sheath is coated with a 45-50µm thick polytetrafluoroethylene nano-coating 11.

[0036] It should be noted that the sheath adopts a double-layer structure, which can effectively improve the cable's overall performance, including radiation resistance and corrosion resistance, and extend its service life. Firstly, the inner sheath uses extruded polyetheretherketone (PEEK) material, which possesses high temperature resistance, corrosion resistance, flame retardancy, hydrolysis resistance, low smoke and low toxicity, and insulation stability. It also has strong resistance to high radiation, and its molecular structure remains stable under radiation conditions, effectively reducing performance degradation. Secondly, the outer sheath uses extruded flame-retardant lead-boron polyethylene (BOPE) material. This material has excellent radiation protection properties, effectively resisting strong radiation and shielding neutron rays and gamma rays, ensuring that the performance of the cable's internal structural materials is not damaged by radiation. Furthermore, flame-retardant BOPE also has good corrosion resistance, high temperature resistance, and flame retardancy. Finally, the sheath surface is coated with a polytetrafluoroethylene (PTFE) nano-coating, which further enhances the cable's corrosion resistance, water resistance, and stain resistance.

[0037] like Figure 2As shown, the protective coating includes a lightweight anti-corrosion and insulating inner coating 81, an expansion-type cable fire-resistant intermediate coating 82, and an organosilicon high-temperature resistant outer paint layer 83, applied sequentially from the inside out on the shielding layer. This forms a comprehensive protection system encompassing "basic protection - fire barrier - extreme environment protection," suitable for complex environments such as humidity, corrosion, and high temperatures. The lightweight anti-corrosion and insulating inner coating is uniformly coated with water-based epoxy lightweight anti-corrosion and insulating paint with a thickness of 1.0-1.2 mm, providing basic protection and isolating the shielding layer from external corrosive media (such as water vapor and chemicals). It provides basic insulation performance, creating a stable base for the subsequent fireproof layer. After water-based epoxy curing, the volume resistivity is ≥1×10¹²Ω·cm, and the dielectric strength is ≥30kV / mm, preventing short circuits between the shielding layer and external conductors and ensuring the stability of cable signal / power transmission. A thickness of 1.0-1.2mm satisfies both corrosion and insulation requirements (too thin and it's easy to miss coating; too thick and it increases the cable's weight), while avoiding a decrease in cable bending performance due to excessive thickness. Furthermore, the intumescent cable fireproof intermediate coating is uniformly applied with a polyurethane elastomer intumescent fireproof coating and has a thickness of 0.4-0.6mm. Upon heating, the coating expands to form a dense char layer, blocking the spread of flames and providing a crucial fire barrier for the cable. It expands 5-8 times its original size when exposed to fire (150-300℃), forming a char layer ≥2.0-3.0mm thick. The polyurethane elastomer and water-based epoxy inner coating are enhanced with a coupling agent (such as KH550) to strengthen the interfacial bond, preventing delamination (peel strength ≥0.5N / mm) and ensuring overall structural stability. Furthermore, the high-temperature resistant silicone outer coating is uniformly applied with a thickness of 45-50µm, serving as a protective layer against extreme environments (≥600℃) or prolonged high temperatures. In the environment, it protects the inner coating and cable substrate from high-temperature damage, extending the life of the fireproof system; the silicone resin (such as methyl phenyl silicone resin) forms a stable network through -Si-O- bonds (bond energy 452kJ / mol), with a long-term operating temperature ≥200℃ and a short-term temperature resistance ≥600℃, preventing the outer layer from failing in a fire; the ultra-thin design of 45-50μm (traditional ceramic coating thickness ≥200μm) significantly reduces the cable's self-weight; the silicone resin is resistant to ultraviolet aging (QUV test ≥5000h, gloss loss rate <30%), suitable for outdoor or high-light scenarios, maintaining protective performance for a long time.

[0038] In summary, this application aims to provide a high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants. By optimizing the cable structure and material selection, the cable's radiation resistance, high-temperature resistance, chemical corrosion resistance, fire resistance, and electromagnetic interference resistance are improved, while maintaining the cable's flexibility and service life, to meet the high requirements of nuclear power plants for cable operation.

[0039] There are many specific applications of this utility model. The above description is only a preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this utility model, and these improvements should also be considered within the protection scope of this utility model.

Claims

1. A high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants, characterized in that... The cable core consists of multiple insulated cores twisted together in a 1+6 arrangement, with lightweight, low-smoke, halogen-free, and highly flame-retardant filler rope filling the gaps in the core. The core is then wrapped with a polyimide film tape and a shielding layer. The shielding layer comprises an inner shielding layer and an outer shielding layer. The inner shielding layer is made of aluminum-plastic composite tape with a thickness of 0.08-0.12mm and a width of 50-100mm, wrapped in an overlapping manner with the aluminum side facing inwards and an overlap rate of 15%-25%. The outer shielding layer is woven from Inconel nickel alloy wire with a diameter of 0.05-0.1mm, a braiding density of 80%-90%, and a braiding angle of 50-60°. A protective coating is then applied to the outside of the shielding layer, and an extruded sheath is formed around the protective coating. The sheath has a double-layer structure: the inner sheath is extruded from polyetheretherketone (PEEK) material, and the outer sheath is extruded from flame-retardant lead-boron polyethylene (BOPE) material. The surface of the sheath is coated with a 45-50µm thick polytetrafluoroethylene (PTFE) nano-coating.

2. The high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants according to claim 1, characterized in that: The insulated wire core includes a conductor, and an insulating layer is wrapped around the conductor. The insulating layer includes an inner insulating layer and an outer insulating layer. The inner insulating layer is made of a PTFE film tape with a thickness of 0.15 mm, with a wrapping overlap rate of 15%-25%, a thickness of 0.15±0.01 mm, a width of 50-80 mm, and a tensile strength ≥30 MPa. The outer insulating layer is made of fluorinated ethylene propylene copolymer with a thickness of 0.6-0.8 mm, an extrusion thickness of 0.6-0.8 mm, a melt index of 0.5-1.5 g / 10 min, and a density of 2.1-2.3 g / cm³.

3. The high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants according to claim 2, characterized in that: The conductor is made of nickel-plated copper wire twisted in a 1+6 arrangement, which meets the requirements of GB / T 3956 for the second type of circular twisted structure.

4. A high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants according to claim 3, characterized in that: The nickel-plated copper wire has a plating thickness of 5-10 μm, a wire diameter of 0.1-1.0 mm, and a stranding pitch of 100-200 mm.

5. A high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants according to claim 1, characterized in that: The protective coating comprises a lightweight anti-corrosion and insulating inner coating applied sequentially from the inside to the outside of the shielding layer, an expansion-type cable fire-retardant intermediate coating, and an organosilicon high-temperature resistant outer coating.

6. A high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants according to claim 5, characterized in that: The lightweight anti-corrosion and insulating inner coating is uniformly coated with water-based epoxy lightweight anti-corrosion and insulating paint with a thickness of 1.0-1.2mm.

7. A high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants according to claim 5, characterized in that: The intumescent cable fireproof intermediate coating is uniformly applied by polyurethane elastomer intumescent fireproof coating with a thickness of 0.4-0.6 mm.

8. A high-temperature resistant, corrosion-resistant, and fire-resistant control cable for nuclear power plants according to claim 5, characterized in that: The high-temperature resistant silicone outer coating is formed by uniformly coating with a silicone high-temperature resistant coating and has a thickness of 45-50 μm.

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