Radiation resistant halogen-free flame-retardant power cable for nuclear power plants
By using a multi-layered composite cable structure, the problems of reduced insulation performance and unstable signal in the power cables used in nuclear power plants under strong radiation and mechanical shock environments have been solved, achieving high stability and long service life for the cables.
Patent Information
- Application Number
- CN202522090110.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-28
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-09-28
AI Technical Summary
Traditional nuclear power plant power cables are prone to aging and cracking under strong radiation, high temperature, high humidity and mechanical impact, resulting in decreased insulation performance, unstable signal transmission, poor buffering effect and short service life.
It adopts a multi-layer composite design, including a composite conductor, a double-layer nested insulation layer, a three-dimensional braided shielding layer, a honeycomb buffer isolation layer, and a corrugated halogen-free flame-retardant armor layer. Each layer works closely together to form a functionally complementary integrated structure, enhancing insulation, shielding, and buffering performance.
It significantly improves the insulation performance and structural stability of the cable, reduces the risk of mechanical impact damage, extends the service life of the cable, and meets the high requirements of nuclear power plants.
Smart Images
Figure CN224682838U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cable technology, and more specifically, to a radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants. Background Technology
[0002] In the nuclear power plant operation system, power cables are the core carriers of energy transmission and signal transmission. Their operational stability is directly related to the safety level and operation and maintenance efficiency of the nuclear power plant. In particular, Class 1E K1 cables need to be exposed to harsh environments with strong radiation, high temperature, high humidity and potential mechanical impact for a long time, which puts extremely high requirements on the radiation resistance, halogen-free flame retardancy, structural stability and service life of the cables. Currently, traditional power cables used in nuclear power plants have several technical shortcomings: First, most cables use a single-layer insulation structure, which is prone to aging and cracking under long-term strong radiation, leading to a sharp decline in insulation performance and increasing the risk of leakage. Second, the shielding layer mostly adopts a planar winding structure, resulting in uneven shielding effectiveness and difficulty in effectively resisting the complex electromagnetic interference of nuclear power plants, which can easily affect the stability of cable signal transmission. Third, the buffer isolation layer is mostly made of ordinary rubber, with a simple structure. When faced with mechanical impacts generated by equipment start-up and shutdown or external vibrations, the buffering and energy absorption effect is poor, which can easily cause damage to the internal conductors or insulation layers. This leads to deformation and breakage after long-term use, shortening the overall service life of the cable. Utility Model Content
[0003] The purpose of this utility model is to solve the problems mentioned in the background art above, and then to propose a radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants.
[0004] The technical solution adopted by this utility model to solve its technical problem is: A radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants includes a composite conductor, a double-layer nested insulation layer on the outside of the composite conductor, a three-dimensional braided shielding layer on the outside of the double-layer nested insulation layer, a honeycomb-shaped buffer isolation layer on the outside of the three-dimensional braided shielding layer, a corrugated halogen-free flame-retardant armor layer on the outside of the honeycomb-shaped buffer isolation layer, and a dotted outer protective layer on the outside of the corrugated halogen-free flame-retardant armor layer.
[0005] Furthermore, the composite conductor is made of multiple strands of sub-conductors twisted together, with each sub-conductor wrapped in an annular metal sleeve. Several arc-shaped grooves are evenly formed on the outer wall of the annular metal sleeve, and the arc-shaped grooves of adjacent annular metal sleeves interlock with each other.
[0006] Furthermore, the double-layer nested insulation layer includes an inner insulation sleeve and an outer insulation sleeve. The outer wall of the inner insulation sleeve is provided with a plurality of axially extending protrusions, and the inner wall of the outer insulation sleeve is provided with a slot that matches the protrusions. The protrusions are embedded in the slot to form a nested structure.
[0007] Furthermore, a gap of 0.1-0.3mm is left between the raised strip and the slot to provide space for thermal expansion and contraction of the insulating sleeve when the temperature changes, thus preventing the insulating sleeve from cracking due to thermal stress.
[0008] Furthermore, the three-dimensional woven shielding layer adopts a double-layer woven structure, with an inner spiral woven layer and an outer cross-woven layer.
[0009] Furthermore, the spiral braided layer has a braiding direction at a 30-45° angle to the cable axis, and the cross braided layer has braiding lines interlacing in mutually perpendicular directions, with the cross braided layer having a greater braiding density than the spiral braided layer.
[0010] Furthermore, the honeycomb-shaped buffer isolation layer has several hexagonal honeycomb holes inside, which are evenly arranged along the cable axis and the hole diameter gradually increases from the inside to the outside.
[0011] Furthermore, the inner wall of the hexagonal honeycomb pores is provided with an arc-shaped transition surface to avoid stress concentration and prevent the buffer layer from cracking under impact.
[0012] Furthermore, the outer wall of the corrugated halogen-free flame-retardant armor layer has a continuous corrugated structure.
[0013] Furthermore, the outer wall of the convex outer protective layer is uniformly distributed with several hemispherical protrusions, and the inner wall of the convex outer protective layer is provided with an annular positioning groove, which is compatible with the continuous corrugated structure.
[0014] Compared with the prior art, the beneficial effects of this utility model are: This utility model adopts a multi-layer composite design, with each structural layer closely cooperating to form a functionally complementary integrated structure. The double-layer nested insulation layer encases the composite conductor, significantly improving the overall thickness and structural strength of the insulation layer. Furthermore, the synergistic effect of the two insulation layers effectively resists the aging and corrosion of the insulation layer caused by the long-term strong radiation environment of a nuclear power plant. The three-dimensional braided shielding layer ensures the stability of the cable's transmission performance, meeting the high requirements of nuclear power plants for cable signal transmission accuracy. The honeycomb buffer layer effectively buffers the impact force on the internal composite conductor, insulation layer, and shielding layer, reducing the risk of structural failure due to mechanical impact and improving the cable's impact resistance and structural stability. Finally, the corrugated halogen-free flame-retardant armor layer and the raised-dot outer protective layer further enhance the cable's durability and extend its overall service life. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the structure of a composite conductor; Figure 3This is a schematic diagram of a double-layered nested insulating layer structure; Figure 4 This is a schematic diagram of the structure of a three-dimensional woven shielding layer; Figure 5 This is a schematic diagram of the honeycomb-shaped buffer isolation layer. Figure 6 A schematic diagram of the corrugated halogen-free flame-retardant armor layer; Figure 7 This is a schematic diagram of the structure of the dotted outer protective layer; Among them: 1. Composite conductor; 11. Sub-conductor; 12. Ring-shaped metal sleeve; 13. Arc-shaped groove; 2. Double-layer nested insulation layer; 21. Inner insulation sleeve; 22. Outer insulation sleeve; 23. Raised strip; 24. Slot; 3. Three-dimensional braided shielding layer; 31. Spiral braided layer; 32. Cross braided layer; 4. Honeycomb buffer isolation layer; 41. Hexagonal honeycomb holes; 5. Corrugated halogen-free flame-retardant armor layer; 51. Continuous corrugated structure; 6. Raised dot outer protective layer; 61. Ring-shaped positioning groove; 62. Hemispherical raised dots. Detailed Implementation
[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model. The present utility model will be further described with reference to the accompanying drawings and embodiments: A radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants, see attached document. Figure 1 As shown, it includes a composite conductor 1, a double-layer nested insulation layer 2 on the outside of the composite conductor 1, a three-dimensional braided shielding layer 3 on the outside of the double-layer nested insulation layer 2, a honeycomb-shaped buffer isolation layer 4 on the outside of the three-dimensional braided shielding layer 3, a corrugated halogen-free flame-retardant armor layer 5 on the outside of the honeycomb-shaped buffer isolation layer 4, and a dotted outer protective layer 6 on the outside of the corrugated halogen-free flame-retardant armor layer 5.
[0017] In this design, the various structural layers work closely together to form a complementary integrated structure. It is a Class 1E K1 cable, which can stably adapt to the high safety requirements of nuclear power plants for a long time and has the advantage of long service life.
[0018] Specifically, refer to the appendix Figure 2As shown, the composite conductor 1 is composed of multiple strands of sub-conductors 11 twisted together. Each sub-conductor 11 is wrapped with an annular metal sleeve 12. Several arc-shaped grooves 13 are evenly distributed on the outer wall of the annular metal sleeve 12, and the arc-shaped grooves 13 of adjacent annular metal sleeves 12 interlock. This interlocking twisted structure increases the contact area between the sub-conductors 11, reduces transmission resistance, and improves conductivity stability. Furthermore, the annular metal sleeve 12 and the interlocking structure together enhance the overall structural strength of the conductor, preventing it from loosening or breaking during long-term use. Simultaneously, the annular metal sleeve 12 can block some radiation from directly acting on the sub-conductors 11, improving radiation resistance. The twist pitch of the composite conductor 1 is 10-15 times its outer diameter, ensuring conductor flexibility for easy installation while further improving structural stability.
[0019] Specifically, refer to the appendix Figure 3 As shown, the double-layer nested insulation layer 2 includes an inner insulation sleeve 21 and an outer insulation sleeve 22. The outer wall of the inner insulation sleeve 21 has several axially extending protrusions 23, and the inner wall of the outer insulation sleeve 22 has slots 24 that fit the protrusions 23. The protrusions 23 are embedded in the slots 24 to form a nested structure, and a gap of 0.1-0.3mm is left between the protrusions 23 and the slots 24. Compared with single-layer insulation, the double-layer nested design significantly improves insulation reliability. Even if one layer of insulation is partially damaged, the other layer can still maintain its insulation effect. The nesting cooperation between the protrusions 23 and the slots 24 achieves precise positioning of the two insulation sleeves, avoiding relative slippage. At the same time, the gap can provide space for thermal expansion and contraction of the insulation sleeves when the temperature changes, preventing the insulation sleeves from cracking due to thermal stress. In addition, the thickness of the inner insulation sleeve 21 is 0.8-1.5mm, and the thickness of the outer insulation sleeve 22 is 0.7-1.5mm. The reasonable distribution of the thickness of the two layers ensures insulation performance while controlling the overall outer diameter of the cable.
[0020] Specifically, refer to the appendix Figure 4 As shown, the three-dimensional braided shielding layer 3 adopts a double-layer braided structure. The inner layer is a spiral braided layer 31, with the braiding direction at a 30-45° angle to the cable axis. The outer layer is a cross-braided layer 32, with the braided threads interlacing in mutually perpendicular directions. The cross-braided layer 32 has a higher braiding density than the spiral braided layer 31. The spiral braided layer 31 can effectively shield electromagnetic interference propagating along the cable axis, while the cross-braided layer 32 provides all-around protection against radial electromagnetic interference. The double-layer three-dimensional structure achieves electromagnetic shielding without dead angles. At the same time, compared with single-layer braiding, the double-layer braiding significantly improves the structural strength, enhances tensile and fracture resistance, and can resist structural failure caused by material aging under radiation environment. In addition, the overall thickness of the shielding layer is 0.3-0.8mm, ensuring shielding and strength performance while avoiding excessive weight increase.
[0021] Specifically, refer to the appendix Figure 5As shown, the honeycomb-shaped buffer isolation layer 4 has several hexagonal honeycomb holes 41 inside. The hexagonal honeycomb holes 41 are evenly arranged along the cable axis, and the hole diameter gradually increases from the inside to the outside. The inner wall of the hexagonal honeycomb hole 41 has an arc-shaped transition surface. The hexagonal honeycomb structure has excellent mechanical properties and can effectively absorb external mechanical impact and vibration energy, protecting the internal structure. The design of the hole diameter gradually increasing from the inside to the outside forms a gradient buffering effect. The larger hole diameter in the outer layer can initially buffer strong impacts, while the smaller hole diameter in the inner layer achieves fine buffering. The arc-shaped transition surface avoids stress concentration and prevents the buffer layer from cracking under impact. In addition, the thickness of the buffer isolation layer is 0.5-1.2mm. The honeycomb structure significantly reduces the amount of material used while ensuring buffering performance, and the air in the hexagonal honeycomb holes 41 can form a heat insulation layer, reducing the impact of external temperature changes on the inside of the cable.
[0022] Specifically, refer to the appendix Figure 6 As shown, the outer wall of the corrugated halogen-free flame-retardant armor layer 5 has a continuous corrugated structure 51, with a height difference of 0.5-1.2 mm between the corrugation peaks and troughs, and a corrugation spacing of 2-5 mm. The corrugated outer wall increases the contact area between the armor layer and the outside environment, which can accelerate heat dissipation and improve the flame-retardant effect in fire scenarios; at the same time, compared with a smooth structure, the corrugated structure has stronger impact resistance and can effectively resist external mechanical damage.
[0023] Specifically, refer to the appendix Figure 7 As shown, the outer wall of the raised outer protective layer 6 is uniformly distributed with several hemispherical protrusions 62, each with a diameter of 0.3-0.8 mm and a spacing of 1-2 mm between adjacent hemispherical protrusions 62. The inner wall of the raised outer protective layer 6 is provided with an annular positioning groove 61, which matches the crest of the corrugated halogen-free flame-retardant armor layer 5. The hemispherical protrusions 62 can reduce the contact area between the cable and the outside environment during cable laying, reducing friction damage. At the same time, the hemispherical protrusions 62 can act as a buffer to resist minor collisions. The matching of the annular positioning groove 61 with the crest of the armor layer achieves a tight connection between the protective layer and the armor layer, avoids relative slippage, and improves the overall structural stability. In addition, the outer protective layer is 1-2.5 mm thick, which can effectively resist external radiation, chemical corrosion, and other erosion, protecting the internal structure of the cable.
[0024] The foregoing has shown and described the main features and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The descriptions of the above embodiments and specifications are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by this utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants, characterized in that: It includes a composite conductor (1), a double-layer nested insulation layer (2) on the outside of the composite conductor (1), a three-dimensional braided shielding layer (3) on the outside of the double-layer nested insulation layer (2), a honeycomb buffer isolation layer (4) on the outside of the three-dimensional braided shielding layer (3), a corrugated halogen-free flame-retardant armor layer (5) on the outside of the honeycomb buffer isolation layer (4), and a raised dotted outer protective layer (6) on the outside of the corrugated halogen-free flame-retardant armor layer (5).
2. The radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants according to claim 1, characterized in that: The composite conductor (1) is formed by twisting together multiple sub-conductors (11). Each sub-conductor (11) is wrapped with an annular metal sleeve (12). Several arc-shaped grooves (13) are evenly opened on the outer wall of the annular metal sleeve (12). The arc-shaped grooves (13) of adjacent annular metal sleeves (12) are interlocked.
3. The radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants according to claim 2, characterized in that: The double-layer nested insulation layer (2) includes an inner insulation sleeve (21) and an outer insulation sleeve (22). The outer wall of the inner insulation sleeve (21) is provided with a number of axially extending protrusions (23). The inner wall of the outer insulation sleeve (22) is provided with a slot (24) that matches the protrusions (23). The protrusions (23) are embedded in the slot (24) to form a nested structure.
4. The radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants according to claim 3, characterized in that: A gap of 0.1-0.3mm is left between the protrusion (23) and the slot (24).
5. A radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants according to claim 4, characterized in that: The three-dimensional braided shielding layer (3) adopts a double-layer braided structure, with the inner layer being a spiral braided layer (31) and the outer layer being a cross braided layer (32).
6. The radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants according to claim 5, characterized in that: The spiral braided layer (31) has a braiding direction at an angle of 30-45° to the cable axis, and the braided lines of the cross braided layer (32) are interwoven in mutually perpendicular directions, and the braiding density of the cross braided layer (32) is greater than that of the spiral braided layer (31).
7. A radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants according to claim 6, characterized in that: The honeycomb-shaped buffer isolation layer (4) has several hexagonal honeycomb holes (41) inside. The hexagonal honeycomb holes (41) are evenly arranged along the cable axis, and the hole diameter gradually increases from the inside to the outside.
8. A radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants according to claim 7, characterized in that: The inner wall of the hexagonal honeycomb hole (41) is provided with an arc-shaped transition surface.
9. A radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants according to claim 8, characterized in that: The outer wall of the corrugated halogen-free flame-retardant armor layer (5) has a continuous corrugated structure (51).
10. A radiation-resistant, halogen-free, flame-retardant power cable for nuclear power plants according to claim 9, characterized in that: The outer wall of the raised outer protective layer (6) is uniformly distributed with several hemispherical raised points (62), and the inner wall of the raised outer protective layer (6) is provided with an annular positioning groove (61) to match the continuous corrugated structure (51).