Fire-resistant control cable for conventional island BOP system and production method

Abstract

The invention provides a fire-resistant control cable for a conventional island BOP system and a production method, and relates to the technical field of control cables, the fire-resistant control cable comprises a cable core structure, the cable core structure comprises at least one conductor, the outer wall of the conductor is coated with a heterogeneous double-layer wrapping tape, the heterogeneous double-layer wrapping tape is coated with a heterogeneous double-layer co-extrusion insulating layer, and the heterogeneous double-layer co-extrusion insulating layer is coated with a fireproof layer. The heterogeneous double-layer co-extrusion insulating layer is coated with a wrapping tape to form a cable core; a plurality of cable cores are twisted to form a cable core structure, gaps of the cable core structure are filled with filling bodies, a halogen-free low-smoke flame-retardant wrapping tape is wrapped outside the cable core structure, a double-layer shielding layer is wrapped outside the halogen-free low-smoke flame-retardant wrapping tape, and an outer sheath is wrapped outside the double-layer shielding layer. The finished cable obtained based on the production method provided by the invention has the characteristics of no halogen, low smoke, flame retardance, fire resistance, low toxicity, corrosion resistance, excellent electrical performance, long service life and the like, and can effectively meet the use environment of cables for conventional island BOP systems.

Description

Technical Field

[0001] The present invention relates to the technical field of control cables, and in particular to a fire-resistant control cable for a conventional island BOP system and a production method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] The safe operation of nuclear power plants is highly dependent on the reliability of their supporting cables. The cables in the Balance of Plant (BOP) system (a general term for auxiliary facilities in a nuclear power plant, excluding the nuclear and conventional islands, including turbines, generators, and cooling systems) must possess strong thermal and chemical stability, excellent aging resistance, moisture and corrosion resistance, halogen-free, low-smoke, flame retardant properties, and a long service life. Cables for specialized applications are even more susceptible to spray-resistant and fire-resistant requirements.

[0004] However, the current BOP system cables generally have the following technical problems: (1) Conventional fire-resistant cables cannot reach a service life of 60 years, and their fire resistance performance is easily lost under spraying conditions; (2) The single-layer insulation structure is prone to aging and cracking in a long-term radiation environment, resulting in degradation of electrical performance; (3) The single-layer shielding structure has insufficient anti-electromagnetic interference capability, which affects the transmission accuracy of the control signal; (4) Traditional sheath materials release toxic smoke when burned, which does not meet the halogen-free and low-smoke requirements of nuclear power plants. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a fire-resistant control cable for a conventional island BOP system and a production method, which has the characteristics of halogen-free, low-smoke flame retardancy, fire resistance, low toxicity, corrosion resistance, excellent electrical properties and long service life, and can effectively meet the use environment of cables for conventional island BOP systems.

[0006] A first aspect of the present invention provides a fire-resistant control cable for a conventional island BOP system, comprising: a cable core structure, the cable core structure comprising at least one conductor (1), the outer wall of the conductor being coated with a heterogeneous double-layer tape, the outer surface of the heterogeneous double-layer tape being coated with a heterogeneous double-layer co-extruded insulation layer, the outer surface of the heterogeneous double-layer co-extruded insulation layer being coated with the tape to form a cable core; A plurality of the cable cores are twisted into a cable core structure, the gaps of the cable core structure are filled with a filler (6), the cable core structure is coated with a halogen-free, low-smoke, flame-retardant tape (7), the halogen-free, low-smoke, flame-retardant tape (7) is coated with a double-layer shielding layer, and the double-layer shielding layer is coated with an outer sheath (10).

[0007] Furthermore, the double-layer shielding layer comprises an inner layer of copper-plastic composite tape shielding (8) and an outer layer of tinned copper wire braided shielding (9).

[0008] Furthermore, the conductor is formed by twisting tinned copper wires.

[0009] Furthermore, the heterogeneous double-layer tape is formed by overlapping and wrapping a ceramicized mica tape (2) and a polyester tape (3).

[0010] Furthermore, the heterogeneous double-layer co-extruded insulation layer comprises an inner insulation layer (4) and an outer insulation layer (5), the inner insulation layer (4) is a radiation cross-linked polyethylene layer, and the outer insulation layer (5) is a radiation cross-linked halogen-free low-smoke flame-retardant polyolefin layer.

[0011] Furthermore, the outer sheath (10) is a radiation cross-linked halogen-free low-smoke flame-retardant polyolefin layer.

[0012] Furthermore, the filler (6) is made of radiation cross-linked halogen-free, low-smoke, flame-retardant polyolefin material.

[0013] Furthermore, in the heterogeneous double-layer co-extruded insulation layer, the thickness ratio of the inner insulation layer to the outer insulation layer is 1:2.

[0014] A second aspect of the present invention provides a method for producing a fire-resistant control cable for a conventional island BOP system, comprising the following steps: A tinned copper stranded conductor is provided; ceramic mica tape and polyester tape are wrapped around the conductor to form a conductor with a heterogeneous tape; the conductor with the heterogeneous tape is input into an extruder, and an irradiation cross-linked polyethylene inner insulation layer and an irradiation cross-linked halogen-free, low-smoke, flame-retardant polyolefin outer insulation layer are simultaneously extruded to obtain a wire core with an insulation layer; the wire core with the insulation layer is subjected to irradiation cross-linking treatment to make the thermal elongation of the insulation layer ≤50% to obtain an insulated wire core; multiple insulated wire cores are twisted into a cable core, and the gaps between the cable cores are filled with irradiation cross-linked halogen-free, low-smoke, flame-retardant polyolefin extruded strips to form a filled cable core; a halogen-free, low-smoke, flame-retardant tape is wrapped around the filled cable core; a copper-plastic composite tape is longitudinally wrapped around the wrapped layer to form an inner shielding layer, and a tinned copper wire is braided outside the inner shielding layer to form an outer shielding layer; an irradiation cross-linked halogen-free, low-smoke, flame-retardant polyolefin outer sheath is extruded outside the shielding layer, and the sheath is subjected to irradiation cross-linking treatment to obtain a finished cable.

[0015] Furthermore, a double-thread screw is used for extrusion of the inner insulation layer, and a low-compression ratio screw is used for extrusion of the outer insulation layer; Before extruding the insulation layer, the conductor is preheated to 60-80°C, the insulation material is dried at 45-60°C for 1-2 hours, and the wire core is cooled in sections. The first section of cooling water is at 45-60°C, and the second section of cooling water is at room temperature. The outer sheath layer is extruded on an extruder unit using a low compression ratio screw and a semi-extrusion die. The material is preheated at 45℃~60℃ for 1~2 hours before extrusion and cooled in sections after extrusion. The cooling water temperature in the first section is 45℃~60℃ and the cooling water temperature in the second section is room temperature. The conductor twist pitch is 16 to 20 times the conductor outer diameter. The outermost layer is twisted to the left, and the adjacent layers are twisted in the opposite direction.

[0016] Compared with the prior art, the fire-resistant control cable for conventional island BOP systems and the production method provided by the present invention have the following beneficial effects: (1) In view of the technical problems in the background art that conventional fire-resistant cables have a short service life and are prone to failure of fire resistance under spraying conditions, the present invention solves this problem by arranging a heterogeneous double-layer wrapping of ceramic mica tape and polyester tape on the outside of the conductor, significantly improving the cable's anti-spray fire resistance and meeting the 120-minute W-class fire resistance test requirements; (2) In order to solve the technical problem in the background technology that the single-layer insulation structure is prone to aging and cracking under long-term radiation environment, the present invention obtains a double-layer co-extruded insulation layer with an inner layer of radiation-crosslinked polyethylene and an outer layer of halogen-free polyolefin based on the radiation cross-linking process, so that the thermal elongation of the insulation layer is reduced to ≤50%, ensuring the service life of the fire-resistant cable for 60 years.

[0017] (3) In order to solve the technical problem that the single-layer shielding structure in the background technology has insufficient anti-electromagnetic interference ability, the present invention uses a double-layer shielding structure woven with copper-plastic composite tape and tinned steel wire to increase the braiding density to ≥90%, thereby enhancing the cable's anti-electromagnetic interference ability.

[0018] (4) In response to the technical problem in the background technology that traditional sheath materials release toxic smoke when burned, the irradiated cross-linked polyethylene inner insulation layer provided by the present invention is resistant to high temperature and aging, is halogen-free, low-smoke and environmentally friendly, and is environmentally friendly and flame-retardant, meeting the safety standards of nuclear power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which constitute a part of the present disclosure, are used to provide a further understanding of the present disclosure. The exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation to the present disclosure.

[0020] Figure 1 This is a schematic structural diagram of a conventional fire-resistant control cable for an island BOP system provided by the present invention; In the figure, 1. Conductor; 2. Ceramic mica tape; 3. Polyester tape; 4. Inner insulation layer; 5. Outer insulation layer; 6. Filler; 7. Halogen-free low-smoke flame-retardant tape; 8. Copper-plastic composite tape shield; 9. Tinned copper wire braided shield; 10. Outer sheath. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0023] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0024] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention, and should not be understood as limiting the present invention.

[0025] In the present invention, terms such as "fixed connection," "connected," and "connection" should be interpreted broadly to mean a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediary. Relevant researchers or technicians in this field may determine the specific meanings of these terms in the present invention based on specific circumstances, and they should not be construed as limitations of the present invention.

[0026] Example 1 The present invention provides a fire-resistant control cable for a conventional island BOP system, comprising: a cable core structure, the cable core structure comprising at least one conductor (1), the outer wall of the conductor being coated with a heterogeneous double-layer tape, the outer surface of the heterogeneous double-layer tape being coated with a heterogeneous double-layer co-extruded insulation layer, the outer surface of the heterogeneous double-layer co-extruded insulation layer being coated with the tape to form a cable core; A plurality of the cable cores are twisted into a cable core structure, the gaps of the cable core structure are filled with a filler (6), the cable core structure is coated with a halogen-free, low-smoke, flame-retardant tape (7), the halogen-free, low-smoke, flame-retardant tape (7) is coated with a double-layer shielding layer, and the double-layer shielding layer is coated with an outer sheath (10).

[0027] The fire-resistant control cable for conventional island BOP systems provided by the present invention has a compact structure and good stability. The sheath layer is made of halogen-free, low-smoke, radiation-resistant cross-linked polyolefin, and has excellent radiation resistance and mechanical properties.

[0028] Specifically, the double-layer shielding layer comprises an inner copper-plastic composite tape shielding (8) and an outer tinned copper wire braided shielding (9).

[0029] Specifically, the conductor is made of twisted tinned copper wires. The twisted conductors provide excellent electrical conductivity. The tin coating prevents oxidation of the copper wires, and the twisted structure enhances the conductor's flexibility and resistance to bending fatigue. The specific pitch and twist direction design reduces eddy current loss and ensures signal transmission stability (measured conductor resistance ≤ 0.0175Ω·mm). 2 / m).

[0030] Specifically, the heterogeneous double-layer tape is formed by overlapping and wrapping a ceramicized mica tape (2) and a polyester tape (3).

[0031] Specifically, the heterogeneous double-layer co-extruded insulation layer comprises an inner insulation layer (4) and an outer insulation layer (5), the inner insulation layer (4) is a radiation cross-linked polyethylene layer, and the outer insulation layer (5) is a radiation cross-linked halogen-free low-smoke flame-retardant polyolefin layer.

[0032] The irradiated cross-linked polyethylene inner insulation layer is resistant to high temperature and aging, is halogen-free and low-smoke, and is environmentally friendly. It protects the wire core from damage and extends the service life of the control cable. The irradiated cross-linked halogen-free and low-smoke polyolefin outer insulation layer has excellent mechanical properties and radiation resistance.

[0033] The outer wall of the conductor adopts inner and outer double-layer insulation, which improves the insulation of the cable, ensures reliable electrical performance, and is more stable during use.

[0034] Specifically, the outer sheath (10) is a radiation cross-linked halogen-free low-smoke flame-retardant polyolefin layer.

[0035] Specifically, the filler (6) is a radiation-crosslinked halogen-free, low-smoke, flame-retardant polyolefin material.

[0036] The sheath material is made of radiation cross-linked halogen-free low-smoke polyolefin. After radiation cross-linking, the material forms a thermosetting material to ensure the service life of the control cable and its resistance to gamma rays.

[0037] Specifically, in the heterogeneous double-layer co-extruded insulation layer, the thickness ratio of the inner insulation layer to the outer insulation layer is 1:2.

[0038] The inner and outer insulation layers are processed by a double-layer co-extrusion process, which has high efficiency and low energy consumption, and avoids the defects of delamination, wrinkling, degumming between the sheath layer and the insulation layer, and loose bonding between the wire core and the insulation.

[0039] In a specific embodiment, Figure 1As shown, a conventional fire-resistant control cable for an island BOP system comprises two conductors (1), wherein the conductors (1) are wrapped with a heterogeneous double-layer tape. The outer wall of the heterogeneous tape is extruded with a heterogeneous double-layer co-extruded insulation layer to form an insulated wire core, and the two insulated wire cores are cabled through a filler (6), a tape layer (7), a copper-plastic composite tape wrapped or longitudinally wrapped shield (8), a tinned copper wire braided shield (9), and an outer sheath (10); the heterogeneous tape is formed by wrapping a ceramic mica tape (2) and a polyester tape (3), and the heterogeneous double-layer co-extruded insulation layer includes an inner insulation layer (4) and an outer insulation layer (5), and the inner insulation layer (4) and the outer insulation layer (5) are made of different materials, the inner insulation layer (3) is made of cross-linked polyethylene material, the outer insulation layer (4) is made of cross-linked halogen-free low-smoke flame-retardant polyolefin material, the filler (6) is made of low-smoke halogen-free flame-retardant polyolefin, the tape layer (7) is made of low-smoke halogen-free flame-retardant tape, and the outer sheath layer (10) is made of low-smoke halogen-free flame-retardant polyolefin.

[0040] Example 2 The present invention provides a method for producing a fire-resistant control cable for a conventional island BOP system, comprising the following steps: S1: Provides tinned copper stranded conductor; S2: Wrap ceramic mica tape and polyester tape around the conductor to form a conductor with heterogeneous tape; S3: feeding the conductor with the heterogeneous tape into an extruder, and simultaneously extruding a radiation cross-linked polyethylene inner insulation layer and a radiation cross-linked halogen-free low-smoke flame-retardant polyolefin outer insulation layer to obtain a wire core with an insulation layer; S4: performing radiation cross-linking treatment on the wire core with the insulation layer so that the thermal elongation of the insulation layer is ≤50%, thereby obtaining an insulated wire core; S5: twisting multiple insulated wire cores into a cable core, and filling the gaps between the cable cores with radiation-cross-linked halogen-free low-smoke flame-retardant polyolefin extrusions to form a filled cable core; S6: Wrap the filled cable core with halogen-free low-smoke flame-retardant tape; longitudinally wrap the copper-plastic composite tape around the wrapping layer to form an inner shielding layer, and braid tinned copper wire around the inner shielding layer to form an outer shielding layer; S7: Extruding a radiation cross-linked halogen-free low-smoke flame-retardant polyolefin outer sheath outside the shielding layer, and performing radiation cross-linking treatment on the sheath to obtain a finished cable.

[0041] Specifically, in S3, a double-thread screw is used for extrusion of the inner insulation layer, and a low-compression ratio screw is used for extrusion of the outer insulation layer; Before extruding the insulation layer, the conductor is preheated to 60-80°C, the insulation material is dried at 45-60°C for 1-2 hours, and the wire core is cooled in sections. The first section of cooling water is at 45-60°C, and the second section of cooling water is at room temperature. The outer sheath layer is extruded on an extruder unit using a low compression ratio screw and a semi-extrusion die. The material is preheated at 45℃~60℃ for 1~2 hours before extrusion and cooled in sections after extrusion. The cooling water temperature in the first section is 45℃~60℃ and the cooling water temperature in the second section is room temperature. The conductor twist pitch is 16 to 20 times the conductor outer diameter, the outermost layer is laid to the left, and the adjacent layers are laid in the opposite direction; the overlap rate of heterogeneous tape is controlled at 15% to 20%.

[0042] In a specific embodiment, the method steps can be summarized as follows: including conductor material selection - heterogeneous tape wrapping - inner insulation layer and outer insulation layer extrusion - inner insulation layer and outer insulation layer radiation cross-linking treatment - cabling - filling - cabling wrapping - copper-plastic composite tape wrapping or longitudinal wrapping shielding - tinned copper wire braided overall shielding - outer sheath extrusion - outer sheath radiation cross-linking treatment.

[0043] The following is a detailed description of each step: Conductor material selection: The conductor is made of stranded tinned copper material, with a regular stranded circle and a stranding pitch of 16 to 20 times the outer diameter of the conductor. The outermost layer is laid in the left direction, and the adjacent layers are laid in the opposite direction.

[0044] Heterogeneous tape wrapping: Heterogeneous tape is wrapped with one layer of ceramic mica tape and one layer of polyester tape, with the overlap rate controlled at 15%-20%.

[0045] The ceramic mica tape forms a ceramic hard shell at high temperatures (it does not melt after a 120-minute fire test), while the polyester tape provides mechanical support. The two work together to enable the cable to pass the Class W spray fire test. The overlap rate is precisely controlled to avoid wrapping that is too loose (risk of fire leakage) or too tight (cable bending and cracking).

[0046] Inner and outer insulation layers are extruded: The inner and outer insulation layers are co-extruded. The inner insulation is made of radiation-cross-linked polyethylene, while the outer insulation is made of radiation-cross-linked halogen-free, low-smoke, flame-retardant polyolefin. The thickness ratio of the inner and outer layers is 1:2. The inner insulation is extruded using a conventional twin-thread screw, while the outer insulation is extruded using a low-compression screw. Before extruding the insulation layer, the conductor should be preheated to 60-80°C, and the insulation material should be baked at 45-60°C for 1-2 hours. The wire core is cooled in stages, with the cooling water temperature in the first stage at 45-60°C and the second stage at room temperature. This is a reference temperature during extrusion and can be adjusted based on actual conditions.

[0047]

[0048] Irradiation cross-linking treatment of inner and outer insulation layers: The inner and outer insulating layers are irradiated and cross-linked, and the elongation under load is not greater than 50%.

[0049] Cabling: The outermost layer is laid in a right-hand direction, with adjacent layers laid in opposite directions. In this embodiment, the maximum cable pitch is 25 times. The sheath is filled with extruded strips of irradiated, cross-linked, halogen-free, low-smoke, flame-retardant polyolefin material. The cable wrapping tape is wrapped with two overlapping layers of low-smoke, halogen-free, flame-retardant tape, with an overlap ratio of 15% to 20%.

[0050] Filler bars are extruded using a low-compression screw through a semi-extrusion die. The material should be preheated to 45°C to 60°C for 1-2 hours before extrusion. After extrusion, the material is cooled in stages, with the first stage cooling water at 45°C to 60°C and the second stage at room temperature. The reference temperatures during extrusion are as follows; they can be adjusted based on actual conditions.

[0051]

[0052] Double shielding: The double-layer shielding material is copper-plastic composite tape and tinned copper wire. The inner shield is longitudinally wrapped or wrapped with the copper-plastic composite tape, with an overlap rate of no less than 15%. The copper side of the copper-plastic composite tape faces outward, and the plastic film faces inward. The appearance should be smooth. The outer shield is a braided shield made of tinned round copper wire. The braid density should be no less than 90%, and the braid pitch should be uniform. Exposed thread ends should be trimmed during braiding, and the wire spindle is allowed to be replaced once every 1 meter. The longitudinal wrapping and braiding of the copper-plastic composite tape are produced simultaneously.

[0053] Outer sheath layer extrusion: The outer sheath layer is extruded using a low-compression screw on an extruder with a semi-extrusion die. The material should be preheated at 45°C to 60°C for 1 to 2 hours before extrusion. After extrusion, it is cooled in stages, with the first stage cooling water at 45°C to 60°C and the second stage at room temperature. The reference temperatures during extrusion are as follows; they can be adjusted based on actual conditions.

[0054]

[0055] The outer sheath is irradiated and cross-linked layer by layer: The sheath layer is irradiated and cross-linked, and the elongation under load is not more than 50%.

[0056] During the production process, the inner insulating layer, the outer insulating layer and the sheath layer are irradiated and cross-linked to be halogen-free and low-smoke. During the irradiation cross-linking process, the insulation does not come into contact with moisture, thereby reducing the probability of electrical performance problems of the cable due to the incorporation of moisture. Irradiation cross-linking is particularly suitable for the production of special cables. The insulating material is modified by a high-energy electron beam. The high-energy rays destroy the original linear CH bonds, and then the molecular structure is recombined to form an irregular network molecular structure, which improves the mechanical and physical properties and temperature resistance of the material, and the electrical properties are also improved to a certain extent. At the same time, since the material is irradiated with high-energy electron rays on organic thermoplastic materials, the linear polymer is transformed into a three-dimensional network cross-linked structure; that is, the thermoplastic is converted into an infusible hot solid substance, which improves and enhances the physical and mechanical properties. In addition, the irradiation cross-linking method can avoid the low-smoke and halogen-free characteristics being destroyed by chemical cross-linking.

[0057] The cable test in the above embodiment has the following performance: The cable insulation mechanical properties are good before and after aging. Before aging, the minimum tensile strength reaches 10.0 MPa, and the minimum elongation at break reaches 200%. After aging, the change rate of tensile strength and elongation at break does not exceed ±25%. The maximum elongation under load in the insulation thermal extension test does not exceed 50%, and the maximum permanent deformation elongation after cooling is 15%.

[0058] The sheath performance must meet the following requirements: the minimum tensile strength before aging must be 9.0 MPa, the minimum elongation at break must be 150%, and the change in tensile strength and elongation at break after aging must not exceed ±25%. The maximum elongation under load in the thermal extension test must not exceed 50%, and the maximum permanent set elongation after cooling must be 15%.

[0059] The cable has passed the thermal aging simulation test which is equivalent to an accelerated thermal aging test of 60 years of operation, and the mechanical properties of the insulation and sheath meet the requirements.

[0060] Class W fire resistance test (test time 120 minutes, water spray or jet application).

[0061] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

[0062] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A fire-resistant control cable for a conventional island BOP system, characterized in that: The cable core structure comprises at least one conductor (1), the outer wall of the conductor is covered with a heterogeneous double-layer tape, the heterogeneous double-layer tape is covered with a heterogeneous double-layer co-extruded insulation layer, and the heterogeneous double-layer co-extruded insulation layer is covered with the tape to form a cable core; A plurality of the cable cores are twisted into a cable core structure, the gaps of the cable core structure are filled with a filler (6), the cable core structure is coated with a halogen-free, low-smoke, flame-retardant tape (7), the halogen-free, low-smoke, flame-retardant tape (7) is coated with a double-layer shielding layer, and the double-layer shielding layer is coated with an outer sheath (10).

2. The fire-resistant control cable for conventional island BOP system according to claim 1, characterized in that: The double-layer shielding layer comprises an inner copper-plastic composite tape shielding (8) and an outer tinned copper wire braided shielding (9).

3. The fire-resistant control cable for conventional island BOP system according to claim 1, characterized in that: The conductor is formed by twisting tinned copper wires.

4. The fire-resistant control cable for conventional island BOP system according to claim 1, characterized in that: The heterogeneous double-layer tape is formed by overlapping and wrapping a ceramicized mica tape (2) and a polyester tape (3).

5. The fire-resistant control cable for conventional island BOP system according to claim 1, characterized in that: The heterogeneous double-layer co-extruded insulation layer comprises an inner insulation layer (4) and an outer insulation layer (5), the inner insulation layer (4) is a radiation cross-linked polyethylene layer, and the outer insulation layer (5) is a radiation cross-linked halogen-free low-smoke flame-retardant polyolefin layer.

6. The fire-resistant control cable for conventional island BOP system according to claim 1, characterized in that: The outer sheath (10) is a radiation cross-linked halogen-free, low-smoke, flame-retardant polyolefin layer.

7. The fire-resistant control cable for conventional island BOP system according to claim 1, characterized in that: The filler (6) is made of radiation-crosslinked halogen-free, low-smoke, flame-retardant polyolefin material.

8. The fire-resistant control cable for conventional island BOP system according to claim 1, characterized in that: In the heterogeneous double-layer co-extruded insulation layer, the thickness ratio of the inner insulation layer to the outer insulation layer is 1:

2.

9. The method for producing a fire-resistant control cable for a conventional island BOP system according to any one of claims 1 to 8, characterized in that: The following steps are involved: A tinned copper stranded conductor is provided; ceramic mica tape and polyester tape are wrapped around the conductor to form a conductor with a heterogeneous tape; the conductor with the heterogeneous tape is input into an extruder, and an irradiation cross-linked polyethylene inner insulation layer and an irradiation cross-linked halogen-free, low-smoke, flame-retardant polyolefin outer insulation layer are simultaneously extruded to obtain a wire core with an insulation layer; the wire core with the insulation layer is subjected to irradiation cross-linking treatment to make the thermal elongation of the insulation layer ≤50% to obtain an insulated wire core; multiple insulated wire cores are twisted into a cable core, and the gaps between the cable cores are filled with irradiation cross-linked halogen-free, low-smoke, flame-retardant polyolefin extruded strips to form a filled cable core; a halogen-free, low-smoke, flame-retardant tape is wrapped around the filled cable core; a copper-plastic composite tape is longitudinally wrapped around the wrapped layer to form an inner shielding layer, and a tinned copper wire is braided outside the inner shielding layer to form an outer shielding layer; an irradiation cross-linked halogen-free, low-smoke, flame-retardant polyolefin outer sheath is extruded outside the shielding layer, and the sheath is subjected to irradiation cross-linking treatment to obtain a finished cable.

10. The production method according to claim 9, characterized in that The inner insulation layer is extruded with a double-thread screw, and the outer insulation layer is extruded with a low-compression ratio screw; Before extruding the insulation layer, the conductor is preheated to 60-80°C, the insulation material is dried at 45-60°C for 1-2 hours, and the wire core is cooled in sections. The first section of cooling water is at 45-60°C, and the second section of cooling water is at room temperature. The outer sheath layer is extruded on an extruder unit using a low compression ratio screw and a semi-extrusion die. The material is preheated at 45℃~60℃ for 1~2 hours before extrusion and cooled in sections after extrusion. The cooling water temperature in the first section is 45℃~60℃ and the cooling water temperature in the second section is room temperature. The conductor twist pitch is 16 to 20 times the conductor outer diameter. The outermost layer is twisted to the left, and the adjacent layers are twisted in the opposite direction.

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