CN104183322B - 1E-grade instrument cable for third-generation passive nuclear power plant gentle environment and production method - Google Patents

Abstract

The invention provides a Class 1E instrument cable for a third-generation passive nuclear power plant in a moderate environment and a production method. The Class 1E instrument cable has halogen-free, low-smoke, flame-retardant, low toxicity, corrosion resistance, and excellent electrical performance. Class 1E instrument cables for third-generation passive nuclear power plants in mild environments, including multiple cores and more than one filler core; the cores include more than one conductor, and the outer wall of each conductor is wrapped with a first tape, and the first tape is extruded inside the wrapping The insulating layer and the outer insulating layer are wrapped with a second tape; the wire core and the filler core are twisted into a cable core; the cable core is sequentially provided with a tape layer, a filling layer, an inner shielding layer, an outer shielding layer, and a winding Cladding and jacketing layers. The production method of the 1E class instrument cable comprises the following steps: conductor stranding, conductor wrapping, inner insulating layer and outer insulating layer extrusion wrapping, inner insulating layer and outer insulating layer irradiation cross-linking treatment, insulating wrapping, Cable core and core filling-filling layer extrusion-shielding-sheath layer extrusion-sheath layer radiation cross-linking treatment.

Description

Class 1E instrumentation cables for mild environments of third-generation passive nuclear power plants and their production methods

technical field

The invention relates to a cable and a production method, in particular to a third-generation passive nuclear power plant mild environment 1E grade instrument cable and a production method.

Background technique

In the 21st century, the growth of population and economy in developing countries will inevitably bring about a huge increase in energy demand. At the same time, the fuel that provides more than 80% of the current electricity is gradually exhausted, and environmental protection requirements have a great impact on the use of fuel. limits. From the protection of resources, the improvement of environmental quality and the reliable supply of energy, nuclear energy has obvious advantages.

In the special operating environment of nuclear power plants, as supporting cables for nuclear power plants, they must have strong thermal stability, good chemical stability, excellent radiation resistance, excellent aging resistance, moisture resistance, corrosion resistance, halogen-free low-smoke flame retardant, long service life, etc. features. At this stage, the high-end products of domestic nuclear power cables rely on imports, and only some products can be localized.

Contents of the invention

The invention provides a class 1E instrument cable for a third-generation passive nuclear power plant in a mild environment and a production method. The class 1E instrument cable has halogen-free, low-smoke, flame retardant, low toxicity, corrosion resistance, excellent electrical performance, strong radiation resistance and Features such as long service life.

To achieve the above object, the present invention adopts the following technical solutions:

A third-generation passive nuclear power plant mild environment 1E grade instrument cable, including multiple wire cores and more than one filler core; the wire core includes more than one conductor, and the outer wall of each conductor is wrapped with a first tape, and the first tape is extruded The inner insulation layer and the outer insulation layer are wrapped with a second tape; the core and the filler core are stranded to form a cable core; the cable core is provided with a tape layer, a filling layer, an inner shielding layer, and an outer shielding layer in sequence from the inside to the outside , Wrapping layer and sheath layer.

Further, the filling core includes a reinforcing core, and the reinforcing core is extruded with a filling body, the reinforcing core is made of aramid yarn, and the filling body is made of halogen-free and low-smoke irradiation cross-linked polyolefin.

Further, there are two filling cores and two wire cores, which are arranged symmetrically about the center, and are mutually circumscribed and twisted to form a cable core.

Further, the conductor is twisted tinned copper wire, or the conductor includes a positive electrode conductor and a negative electrode conductor, the positive electrode is a nickel-chromium alloy wire, and the negative electrode conductor is a nickel-silicon alloy wire.

Further, the inner insulating layer is made of halogen-free low-smoke radiation cross-linked polyethylene, and the outer insulating layer is made of halogen-free and low-smoke radiation cross-linked polyolefin.

Further, the inner shielding layer is a braided layer of tinned copper wire, and the outer shielding layer is a longitudinally wrapped copper-plastic composite tape layer.

Further, the filling layer adopts polyolefin oxygen barrier filling material.

Further, both the first wrapping tape and the second wrapping tape are non-hygroscopic polyester film tapes, and the wrapping layer is made of non-hygroscopic halogen-free low-smoke flame-retardant film tape, and the wrapping layer is made of non-woven fabric. Packaged.

A production method of the 1E grade instrument cable is characterized in that it comprises the following steps: conductor stranding - conductor wrapping - inner insulating layer and outer insulating layer extruding - inner insulating layer and outer insulating layer irradiation crosslinking treatment - Insulation wrapping - wire core and core filling into cable - filling layer extrusion - shielding - sheath layer extrusion - sheath layer radiation cross-linking treatment; the thickness ratio of the inner insulation layer to the outer insulation layer is 1:3, the inner insulation layer Ordinary screw is used for insulation extrusion, and low compression ratio screw is used for outer insulation extrusion. Before the insulation layer is extruded, the conductor below 10mm2 should be preheated to 90℃～100℃, and the insulation material should be baked at 60±5℃ for 1 to ² pieces. Hours, in the extrusion process, the temperature of the inner insulating layer is controlled between 140 and 185°C, the temperature of the outer insulating layer is controlled between 90 and 175°C, the core is cooled in sections, and the temperature of the cooling water in the first stage is 60°C~ 70°C, the temperature of the cooling water in the second stage is normal temperature; the sheath layer is extruded with a semi-extrusion tube die on the extrusion unit with a low compression ratio screw, and the material should be preheated at 60±5°C for 1 to 2 hours before extrusion. In the extrusion process, the temperature is controlled at 90-155°C, and segmental cooling is adopted after extrusion. The temperature of the cooling water in the first stage is 60°C-70°C, and the temperature of the cooling water in the second stage is normal temperature; the sheath layer adopts semi-extruded tube extrusion After extrusion, it adopts segmental cooling, the temperature of the first cooling water is 60℃～70℃, and the temperature of the second cooling water is normal temperature; the thermal elongation of the inner insulating layer, outer insulating layer and sheath layer is 50% -100%.

The beneficial effects of the present invention are:

(1) 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, which has excellent radiation-resistant energy and mechanical properties. The cable core and filler are wrapped with a tape layer. , the melting temperature of the filler and the tape layer is higher than the maximum rated working temperature of the cable, the overall strength of the cable is good, the roundness of the cable is good, and it is suitable for working environments with high ambient temperature and poor heat dissipation;

(2) 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;

(3) The wire core is wrapped with a layer of polyester tape. The polyester tape has high temperature resistance, which can effectively prevent the wire core from sticking when the cable undergoes simulated accelerated thermal aging; after the wire core is wrapped with a polyester tape, It can avoid the decline of cable electrical performance caused by core adhesion, and can also effectively improve the life of the cable, and can further guarantee the 60-year service life of the cable from the structural aspect;

(4) The inner and outer shielding layers enhance the anti-interference ability of the instrument cable to the outside world and the stability of signal transmission, and the anti-radiation ability is enhanced. The tinned copper wire braid shielding increases the corrosion resistance of the cable and improves the service life of the cable , to ensure that the cable has strong mechanical properties and anti-electromagnetic interference capabilities;

(5) Halogen-free and low-smoke irradiation cross-linked polyethylene inner insulation layer is resistant to high temperature and aging, halogen-free and low-smoke environmental protection, protects the wire core from damage, prolongs the service life of the cable, and the halogen-free and low-smoke irradiation cross-linked polyolefin outer layer The insulating layer has excellent mechanical properties and radiation resistance

(6) The sheath material of radiation cross-linked halogen-free low-smoke polyolefin is used, and the material is cross-linked by radiation to form a thermosetting material to ensure the service life of the cable and the radiation resistance of gamma rays.

(7) The inner and outer insulating layers are processed by a double-layer co-extrusion process, which has high efficiency and low energy consumption, and avoids the defects of layering, wrinkling, degumming between the sheath layer and the insulating layer, and loose connection between the core and the insulation;

(8) In the production process, the inner insulation layer, outer insulation layer and sheath layer are cross-linked by halogen-free and low-smoke radiation, and do not contact with moisture, thereby reducing the probability of electrical performance problems caused by the incorporation of moisture in the cable; through high-energy Electron beams modify the materials of the inner insulating layer, outer insulating layer and sheath layer. The high-energy rays destroy the original linear C-H bond, and then the molecular structure is recombined to form an irregular network molecular structure, which improves the material quality. Excellent mechanical and physical properties and temperature resistance, the temperature resistance level has increased from 70°C to 90°C, and the electrical properties have also been improved to a certain extent.

The service life of the cable of the invention reaches 60 years, and the cable has no halogen, low smoke, flame retardancy, low toxicity and strong radiation resistance.

Description of drawings

Figure 1 is a schematic structural view of a selected embodiment of the present invention.

Among them, 1. Conductor, 2. First tape, 3. Inner insulation layer, 4. Outer insulation layer, 5. Second tape, 6. Tape layer, 7. Filling layer, 8. Inner shielding layer, 9 . Outer shielding layer, 10. Wrapping layer, 11. Sheath layer, 12. Aramid yarn, 13. Filling body.

detailed description

First of all, it should be pointed out that what is described in this section is only a preferred embodiment for implementing the present invention, and those skilled in the art can make modifications to the technical solutions described here without changing the principle of the present invention. These modifications will also fall within the scope of the present invention.

Example 1

Referring to Figure 1, the third-generation passive nuclear power plant mild environment 1E grade instrument cable includes two wire cores and two filler cores; the wire core includes a conductor 1, and the outer wall of each conductor 1 is wrapped with a first tape 2, the second A wrapping tape 2 is extruded to wrap the inner insulating layer 3 and the outer insulating layer 4 and is wrapped with a second wrapping tape 5; the filling core includes a reinforcing core 12, and the reinforcing core 12 is extruded and wrapped with a filling body 13, and the reinforcing core 12 is aramid yarn The filler 16 is made of halogen-free low-smoke radiation cross-linked polyolefin; the filler core and the wire core are arranged symmetrically about the center, and are cut and stranded with each other to form a cable core, and the cable core is sequentially provided with a tape layer from the inside to the outside 6. Filling layer 7, inner shielding layer 8, outer shielding layer 9, wrapping layer 10 and jacket layer 11.

In this embodiment, the conductor 1 is made of twisted tinned copper wires, the conductor 1 has good electrical conductivity, and the conductor 1 is soft and not easily damaged.

In this embodiment, the inner insulating layer 3 is made of halogen-free and low-smoke irradiation cross-linked polyethylene, which is resistant to high temperature and aging, has no halogen and low-smoke and is environmentally friendly, protects the wire core from damage, and prolongs the service life of the cable; the outer insulating layer 4 Halogen-free and low-smoke radiation cross-linked polyolefin, so that the cable has excellent mechanical properties and radiation resistance.

In this embodiment, the inner shielding layer 8 is a braided layer of tinned copper wire, and the outer shielding layer 9 is a longitudinally wrapped copper-plastic composite tape layer. The copper-plastic composite tape layer has high shielding efficiency, and the longitudinal shielding structure can exert the maximum function of the copper-plastic composite tape, which enhances the anti-interference ability of the control cable to the outside world and the stability of signal transmission, making the cable shielding performance better and anti-radiation ability Reinforcement; tinned copper wire braiding has no direction, good shielding effect, increases the corrosion resistance of the cable, and improves the service life of the cable.

In this embodiment, the sheath layer 11 is made of halogen-free and low-smoke radiation cross-linked polyolefin, so that the cable has excellent mechanical properties and radiation resistance.

In this embodiment, both the first tape 2 and the second tape 5 are non-hygroscopic polyester film tapes, and the tape layer 6 is formed by wrapping non-hygroscopic, halogen-free, low-smoke, flame-retardant film tapes. 10 is made of non-woven fabric, and the performance of the non-hygroscopic polyester film tape can be kept stable for a long time, which can effectively ensure the insulation resistance of the product, and can prevent the outward migration of metal ions, which is beneficial to delay the heat dissipation of the material of the sheath layer 11. Aging process; the wrapping layer 6 is made of non-hygroscopic halogen-free low-smoke flame-retardant film tape, which will not melt under the highest rated working temperature of the cable; the wrapping layer 10 is made of non-woven fabric to prevent The cable core is loose or deformed during bending to ensure the roundness and tightness of the cable core.

In this embodiment, the filling layer adopts polyolefin oxygen barrier filling material, which ensures the round structure of the cable and has good low smoke and flame retardant properties.

A production method of the 1E class instrument cable, comprising the following steps: conductor stranding-conductor wrapping-inner insulating layer and outer insulating layer extrusion wrapping-inner insulating layer and outer insulating layer irradiation cross-linking treatment-insulation winding Wrapping - wire core and core filling into cable - filling layer extrusion - shielding - sheath layer extrusion - sheath layer radiation cross-linking treatment; the thickness ratio of the inner insulation layer to the outer insulation layer is 1:3, and the inner insulation is extruded Ordinary screw is used, and low compression ratio screw is used for external insulation extrusion. Before the insulation layer is extruded, the conductor below 10mm2 should be preheated to 90℃～100℃, and the insulation material should be baked at 60±5℃ for 1～ ² hours. In the exiting process, the temperature of the inner insulating layer is controlled between 140 and 185°C, the temperature of the outer insulating layer is controlled between 90 and 175°C, and the core is cooled in sections. The temperature of the cooling water in the first stage is 60°C to 70°C. The temperature of the cooling water in the second stage is normal temperature; the sheath layer is extruded with a semi-extrusion tube die on the extrusion unit with a low compression ratio screw. The material should be preheated at 60±5°C for 1 to 2 hours before extrusion. The medium temperature is controlled at 90-155°C, and segmental cooling is adopted after extrusion. The temperature of the cooling water in the first stage is 60°C-70°C, and the temperature of the cooling water in the second stage is normal temperature; the sheath layer is extruded by a semi-extruded tube, and After extrusion, adopt segmental cooling, the temperature of the cooling water in the first stage is 60℃～70℃, and the temperature of the cooling water in the second stage is normal temperature.

In this embodiment, the thermal elongation of the inner insulating layer, the outer insulating layer, and the sheath layer is 50%-100%.

The following step by step describes each step in detail:

Conductor stranding:

The conductor is stranded tinned copper material, and the diameter and number of stranded single wires can be adjusted according to the softness requirements to ensure the stability of the conductor structure.

Conductor wrapping:

The conductor wrapping is based on the outer diameter of the conductor of different specifications, and the wrapping tape of the corresponding width is selected for wrapping, and the lapping rate of the wrapping is not less than 50%.

Filler

There are two filling cores in the cable core, and the axial axes of the filling cores are arranged in an inverted triangle shape; the filling cores and the wire cores are circumscribed and stranded with each other. The inner layer is made of aramid yarn as the reinforcing core, the outer layer is made of halogen-free and low-smoke irradiation cross-linked polyolefin, and the inside and outside are combined to form the filling core.

Inner and outer insulation extruded:

The inner insulation layer and the outer insulation layer adopt double-layer co-extrusion. The thickness ratio of the inner insulating layer to the outer insulating layer is ¹ :3. The inner insulating extrusion adopts ordinary screw, and the outer insulating extruding adopts low compression ratio screw. Before the insulating layer is extruded, the conductor below 10mm2 should be preheated to 90～100℃ , the insulating material should be baked at 60±5°C for 1 to 2 hours, the wire core is cooled in sections, the temperature of the first cooling water is 60°C to 70°C, and the temperature of the second cooling water is normal temperature; the sheath layer 8 adopts The low compression ratio screw is extruded with a semi-extruded tubular die on the extrusion unit. The material should be preheated at 60±5°C for 1 to 2 hours before extrusion. After extrusion, it should be cooled in sections. The temperature of the first cooling water is 60°C. ~70°C, the temperature of the cooling water in the second stage is normal temperature. Double-layer co-extrusion is realized through one-time processing. During the production process, there is no need to repeatedly adjust the eccentricity of the wire core to ensure accurate insulation thickness. At the same time, one-time extrusion can avoid contamination and damage to the surface of the inner insulation layer when two extrusions are carried out separately. The problem of damage, so that the inner insulation layer and the outer insulation layer are tightly combined, ensuring the concentricity of the inner insulation layer and the outer insulation layer, improving product quality, reducing processing strength, and the tightness between the double-layer structure makes the electrical performance of the cable better. Advantages.

Radiation cross-linking treatment of inner insulating layer and outer insulating layer:

The inner insulation layer is made of halogen-free low-smoke radiation cross-linked polyethylene, which is high temperature resistant, anti-aging, and protects the wire core from damage; the outer insulation layer is made of halogen-free low-smoke radiation cross-linked polyolefin, which has halogen-free low Smoke flame retardant and environmental protection; the thermal elongation of the inner insulation layer and the outer insulation layer is 50%-100%.

Insulation wrapping:

In order to prevent adhesion during accelerated thermal aging of the insulation, a layer of non-hygroscopic polyester film tape is wrapped around the insulation, and the covering rate is controlled at 15%-20%.

Core and filler cabling:

The cable is filled with extruded tubular filler strips and wrapped with non-hygroscopic, halogen-free, low-smoke, flame-retardant film tape to form a tape layer, and the covering rate of the tape should be less than 20%. The pitch ratio of wire core and filling core is 15-20 to ensure the roundness of the cable.

shield:

The shielding adopts a composite shielding structure; the inner shielding layer 8 is a braided layer of tinned copper wire, and the outer shielding layer 9 is a longitudinally wrapped copper-plastic composite tape layer. The copper-plastic composite tape longitudinally wrapped shielding should be produced simultaneously with the tinned copper wire braided shielding. Ensure the safety of the cable when used.

Sheath layer extrusion:

Use a low compression ratio screw to extrude with a semi-extrusion tube die on the extrusion unit. Before extrusion, the material should be preheated at 60±5°C for 1 to 2 hours. After extrusion, it should be cooled in sections. The temperature of the first cooling water 60 ℃ ~ 70 ℃, the temperature of the cooling water in the second stage is normal temperature.

Radiation cross-linking treatment of sheath layer:

The sheath layer is made of halogen-free low-smoke radiation cross-linked polyolefin, and the thermal elongation rate is 50%-100%.

The cable test of the present invention has the following properties:

Example 2

The difference between this embodiment and Embodiment 1 is that it includes a positive electrode conductor and a negative electrode conductor, the positive electrode is a nickel-chromium alloy wire, and the negative electrode conductor is a nickel-silicon alloy wire.

The cable test of the present invention has the following properties:

Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the present invention can be Modifications or equivalent replacements of the technical solutions without departing from the spirit and scope of the technical solutions of the present invention shall fall within the scope of the claims of the present invention.

Claims (9)

1. A method for producing a Class 1E instrument cable for a third-generation passive nuclear power plant in a mild environment. The Class 1E instrument cable includes multiple wire cores and more than one filler core; the wire core includes more than one conductor, and the outer wall of each conductor is wrapped with a first Tape, the first tape is extruded to wrap the inner insulation layer and the outer insulation layer and is wrapped with a second tape; the core and the filler core are twisted into a cable core; the cable core is sequentially provided with a tape layer, a filler layer, inner shielding layer, outer shielding layer, wrapping layer and sheath layer, characterized in that it comprises the following steps: conductor twisting-conductor wrapping-inner insulating layer and outer insulating layer extruding-inner insulating layer and outer insulating layer Irradiation cross-linking treatment-insulation wrapping-wire core and core filling cable-filling layer extrusion-shielding-sheath layer extrusion-sheath layer radiation cross-linking treatment; the thickness ratio of the inner insulation layer and the outer insulation layer is 1:3, common screw is used for inner insulation extrusion, and low compression ratio screw is used for outer insulation extrusion. Before the insulation layer is extruded, the conductor below 10mm2 should be preheated to 90℃～100℃, and the insulation material should be at 60± ⁵ ℃ Bake for 1 to 2 hours. In the extrusion process, the temperature of the inner insulating layer is controlled between 140 and 185°C, the temperature of the outer insulating layer is controlled between 90 and 175°C, and the core is cooled in sections. The water temperature is 60℃～70℃, and the temperature of the cooling water in the second stage is normal temperature; the sheath layer is extruded with a low compression ratio screw on the extrusion unit with a semi-extrusion tube die, and the material should be preheated at 60±5℃ before extrusion 1 to 2 hours, the temperature in the extrusion process is controlled at 90-155°C, and segmental cooling is adopted after extrusion. The temperature of the first cooling water is 60°C to 70°C, and the temperature of the second cooling water is normal temperature; the inner insulation layer and The thermal elongation of the outer insulating layer and sheath layer is 50%-100%. 2. The production method according to claim 1, characterized in that: the filling core includes a reinforcing core, the reinforcing core is extruded with a filler, the reinforcing core is aramid yarn, and the filler is a halogen-free low-smoke irradiation cross-linked polymer. made of olefins. 3. The production method according to claim 2, characterized in that there are two filler cores and two wire cores, arranged symmetrically about the center, and mutually circumscribed and stranded to form a cable core. 4. The production method according to claim 1, characterized in that: the conductor is twisted from tinned copper wires. 5 . The production method according to claim 1 , wherein the conductor comprises a positive electrode conductor and a negative electrode conductor, the positive electrode is a nickel-chromium alloy wire, and the negative electrode conductor is a nickel-silicon alloy wire. 6. The production method according to claim 1, characterized in that: the inner insulating layer is made of halogen-free low-smoke radiation cross-linked polyethylene, and the outer insulating layer is made of halogen-free and low-smoke radiation cross-linked polyolefin. 7. The production method according to claim 1, characterized in that: the inner shielding layer is a braided layer of tinned copper wire, and the outer shielding layer is a longitudinally wrapped copper-plastic composite tape layer. 8. The production method according to claim 1, characterized in that: the filling layer is made of polyolefin oxygen barrier layer filling material; the sheath layer is made of halogen-free and low-smoke radiation cross-linked polyolefin. 9. The production method according to claim 1, characterized in that: the first tape and the second tape are both non-hygroscopic polyester film tapes, and the tape layer is made of non-hygroscopic halogen-free low-smoke flame-retardant film tape It is made by wrapping, and the wrapping layer is made of non-woven fabric.