CN-121983380-A - Safety early warning cable with temperature sensing function and production process thereof

CN121983380ACN 121983380 ACN121983380 ACN 121983380ACN-121983380-A

Abstract

The invention relates to the technical field of cables, and discloses a safety early warning cable with temperature sensing and a production process thereof, wherein a core temperature measuring channel is formed by arranging a spiral metal protection tube and a temperature measuring optical fiber in a conductor, a redundant temperature measuring system is formed by matching a multi-core sensing optical cable, and the accurate distinction of vibration sources is realized by combining double-path vibration sensing and AI signal identification, and meanwhile, a multi-layer composite isolation layer and a three-dimensional heat conducting network are designed to realize efficient heat diffusion; the production process improves the insulation performance of the cable and the stability of the sensing element through a precise temperature-controlled coextrusion process, an online thermal stress relaxation process and an optical fiber pre-fixing process. The invention obviously improves the reliability of temperature measurement and the vibration identification precision, optimizes the thermal management capability of the cable, prolongs the service life, and can effectively reduce the insulation eccentricity and the pre-crosslinking defect by the production process and improve the overall quality of the product.

Inventors

LIU XING
SHENG JINWEI
YAN ZHENG
DING HONGMEI
ZHANG SHENXUE
ZHU XIAO

Assignees

远东电缆有限公司
新远东电缆有限公司
远东复合技术有限公司

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (10)

1. The safety early warning cable with the temperature sensing function comprises a wrapping tape layer (1), and is characterized in that a plurality of power line insulation wire cores (2) are arranged in the wrapping tape layer (1), a protective layer (3) is arranged outside the wrapping tape layer (1), a first vibration sensing element (4) is arranged in the protective layer (3), and an isolation layer (5) is arranged between the wrapping tape layer (1) and the protective layer (3); the power line insulation wire core (2) comprises a conductor (6) and an insulation layer (7) coated outside the conductor (6), a spiral metal protection tube (8) with a spiral micro groove (22) is arranged in the conductor (6) in a penetrating mode, a temperature measuring optical fiber (9) is arranged in the spiral metal protection tube (8) in a penetrating mode, high-heat-conductivity nano silicone grease (21) is filled between the inner wall of the spiral metal protection tube (8) and the temperature measuring optical fiber (9), a conductor copper wire (23) is embedded in the spiral micro groove (22), hollow-out supports (24) are arranged among the plurality of power line insulation wire cores (2), a filling layer (10) for filling a graphene composite heat-conducting material (11) is arranged at a gap between each support (24) and the power line insulation wire core (2), a copper-aluminum composite heat-conducting metal belt (12) in contact with the graphene composite heat-conducting material (11) is arranged on the surface of the insulation layer (7), a multi-core sensing optical cable (13) is arranged at the center of the filling layer (10), the multi-core sensing optical cable (13) comprises at least three multi-mode optical fiber cores (14) and at least one single-mode optical fiber core (15) based on the phi-OTDR technology, the multi-mode optical fiber cores (14) are welded with the end parts of the temperature measuring optical fibers (9) in a one-to-one correspondence mode, and the outer surface of the multi-core sensing optical cable (13) is tightly attached to the graphene composite heat conducting material (11) through holes of the bracket (24).
2. The safety precaution cable with temperature sensing according to claim 1, wherein the isolation layer (5) comprises an inner shielding layer (17), an intermediate heat conducting layer (18) and an outer buffer layer (19) which are sequentially arranged from inside to outside, the inner shielding layer (17) is a semiconductor metal composite layer, the intermediate heat conducting layer (18) is a ring-shaped continuous structure compounded by graphene films, the outer buffer layer (19) is made of EPDM elastomer materials, a plurality of heat conducting windows (20) are axially arranged on the wrapping tape layer (1) at intervals, the graphene composite heat conducting materials (11) in the filling layer (10) are made to contact with the intermediate heat conducting layer (18) of the isolation layer (5) to form a heat conducting path, and the first vibration sensing element (4) and the single-mode fiber cores (15) in the multi-core sensing optical cable (13) are connected to the precaution system of the same integrated AI algorithm in a signal mode.
3. The safety precaution cable with temperature induction according to claim 1, characterized in that the single-mode fiber core (15) in the multi-core sensing optical cable (13) forms an acoustic coupling path with the surface of the insulating layer (7) of each conductor (6) through the graphene composite heat conducting material (11) of the filling layer (10), the graphene composite heat conducting material (11) has the dual functions of sound transmission and heat conduction, the heat conductivity coefficient is more than or equal to 5W/(m.K), and the flexibility is kept within the range of-40 ℃ to 120 ℃.
4. The safety precaution cable with temperature sensing according to claim 2, characterized in that the surface of the middle heat conducting layer (18) is provided with an array type microprotrusion structure, the microprotrusion structure is embedded into the outer buffer layer (19), the inner shielding layer (17), the middle heat conducting layer (18) and the outer buffer layer (19) are formed at one time through a three-layer coextrusion process, and the interlayer bonding force is more than or equal to 1.5N/mm.
5. The safety precaution cable with temperature induction according to claim 2, characterized in that the precaution system performs time-frequency analysis and pattern recognition on signals of the first vibration sensing element (4) and the single-mode fiber core (15) through an AI algorithm, establishes a vibration feature library, realizes accurate distinction between internal fault vibration, external invasion vibration and environment interference vibration, and has an effective precaution accuracy of not less than 98%.
6. The safety precaution cable with temperature induction according to claim 1, characterized in that the copper-aluminum composite heat conduction metal belt (12) is a copper-aluminum composite belt, is spirally wound along the axial direction of the insulating layer (7), the winding pitch is 1-1.5 times of the outer diameter of the cable, and the radially extending end of the copper-aluminum composite heat conduction metal belt (12) is tightly attached to the graphene composite heat conduction material (11) of the filling layer (10) to form a radial heat conduction path.
7. A process for producing a safety precaution cable with temperature sensing according to any one of claims 1 to 6, characterized in that it comprises the following steps: S1, preassembling a conductor and a temperature measuring optical fiber (9), namely embedding a conductor copper wire (23) into a spiral micro groove (22) of a spiral metal protection tube (8), filling high-heat-conductivity nano silicone grease (21) in the spiral metal protection tube (8), penetrating the temperature measuring optical fiber (9), and centering and fixing the temperature measuring optical fiber (9) by adopting an optical fiber positioning clamp to form a temperature measuring conductor core; S2, extruding a power line insulating wire core, namely extruding an insulating layer (7) and a copper-aluminum composite heat conducting metal belt (12) from a temperature measuring conductor core through a three-layer co-extruder, controlling the processing temperature of an insulating material to be 115-120 ℃, and controlling the processing temperature of a shielding material to be 112-116 ℃, wherein an extrusion die adopts a combined extrusion die, so that the insulation eccentricity is less than or equal to 1%; S3, integrating the filling layer with the multi-core sensing optical cable, namely placing a plurality of power line insulation wire cores (2) in a hollowed-out bracket (24), filling graphene composite heat conduction materials (11) in gaps of the bracket (24), and simultaneously fixing the multi-core sensing optical cable (13) at the central position of the bracket (24) to ensure that the multi-core sensing optical cable (13) and a copper-aluminum composite heat conduction metal belt (12) form a heat conduction path; s4, forming a wrapping tape layer and an isolation layer, namely wrapping the wrapping tape layer (1) on the outer side of the filling layer (10) and forming a heat conduction window (20), and then forming an inner shielding layer (17), an intermediate heat conduction layer (18) and an outer buffer layer (19) at one time through a coextrusion process, wherein the temperature uniformity error of a coextrusion machine head is less than or equal to +/-2 ℃; S5, assembling the protective layer and the vibration sensing element, namely extruding the protective layer (3) outside the isolation layer (5), and pre-burying the first vibration sensing element (4) in the protective layer (3) at the same time, so as to ensure that the first vibration sensing element (4) is in signal communication with a single-mode fiber core (15) of the multi-core sensing optical cable (13); s6, performing on-line thermal stress relaxation and detection, namely performing on-line thermal stress relaxation treatment on the formed cable, heating the cable to a temperature higher than the crystallization temperature of the crosslinked polyethylene, slowly cooling, and then performing temperature measurement, vibration measurement signal detection and insulation performance detection.
8. The production process according to claim 7, wherein the optical fiber positioning clamp in the step S1 is an elastic silica gel clamp, and the inner wall of the clamp is provided with a spiral groove matched with the spiral metal protection tube (8), so that the temperature measuring optical fiber (9) can be prevented from being deviated or worn in subsequent processing, and the positioning deviation of the temperature measuring optical fiber (9) is less than or equal to 0.1mm.
9. The production process according to claim 7, wherein the heating temperature of the on-line thermal stress relaxation treatment in step S6 is 130-140 ℃, the heat preservation time is 5-8min, the cooling rate is controlled to be 2-3 ℃ per min, and the radial thermal stress in the insulating layer (7) is effectively eliminated, so that the generation of micro cracks is avoided.
10. The process according to claim 7, wherein the three-layer co-extruder in step S2 has a three-stage filter structure, the mesh number of the filter is 80 mesh, 120 mesh, 200 mesh in order, and the filter is replaced every 5 days of continuous production, so as to prevent accumulation of pre-crosslinked insulating material products to form coke particles and impurities.

Description

Safety early warning cable with temperature sensing function and production process thereof Technical Field The invention relates to the technical field of cables, in particular to a safety early warning cable with temperature sensing and a production process thereof. Background The power cable is used as a core carrier for power transmission, and the real-time monitoring and the safety pre-warning of the running state of the power cable are critical to the stability of a power system. At present, the temperature measurement and vibration measurement monitoring of the power cable in the industry mainly adopts a mode of laying sensing optical fibers later, namely, after the conventional cable is laid, the temperature measurement optical fibers and the vibration optical fibers are bundled on the surface of the cable and then connected into a monitoring host. The method has the defects that the optical fiber can only detect the surface temperature of the cable, the core temperature of the conductor cannot be reflected, the response lag is caused by long heat conduction path, the optical fiber is not tightly combined with the surface of the cable and is easy to be interfered by external environment, the false alarm rate of temperature measurement and vibration measurement is high, and the vibration monitoring can only sense external vibration and cannot identify micro vibration caused by the internal fault of the cable. In order to solve the problems, the prior art integrates the temperature measuring optical fiber into the conductor, the vibrating optical fiber is arranged in the protective layer, the monitoring accuracy is improved to a certain extent, but the defects that the temperature measurement is a single path, a cross verification mechanism is not needed, poor contact or damage of the optical fiber can lead to temperature measurement failure, the vibration sensing can not distinguish an internal vibration source from an external vibration source, false alarm or missing alarm is easy to generate, the isolation layer only has an electromagnetic shielding function, the filling layer only plays a supporting role, the thermal management is not participated, the heat of the conductor is easy to be accumulated locally to form hot spots, and the current-carrying capacity and the service life of the cable are affected. Meanwhile, the existing cable production process has various quality control difficulties that pre-crosslinked products are easily generated due to improper temperature control in the process of extrusion of an insulating layer to form coke particles and impurities, the co-extrusion process is easy to cause insulation eccentricity to exceed standard to cause electric field distortion, optical fibers are easy to deviate and abrade in the process of processing to influence sensing performance, and thermal stress in the insulating layer after cable molding cannot be effectively eliminated, tiny cracks are easily generated to reduce insulating strength. In addition, the existing monitoring system can only conduct simple time sequence and intensity comparison on vibration signals, cannot accurately distinguish environmental interference, external invasion and internal faults, and is low in early warning accuracy, the graphene composite heat conducting material for the cable is mostly made of single materials, heat conductivity and flexibility are difficult to achieve, and heat conduction and buffering requirements cannot be met simultaneously. Disclosure of Invention The invention aims to solve the technical problems of lag temperature measurement response, high false alarm rate of vibration monitoring, heat management deficiency and production process quality defect of the existing cable. The technical scheme includes that the safety early warning cable with the temperature sensing function comprises a wrapping band layer, wherein a plurality of power line insulation wire cores are arranged inside the wrapping band layer, a protective layer is arranged outside the wrapping band layer, a first vibration sensing element is arranged inside the protective layer, and an isolation layer is arranged between the wrapping band layer and the protective layer. Each power line insulation wire core comprises a conductor and an insulation layer coated outside the conductor, a spiral metal protection tube is arranged in each conductor, a temperature measuring optical fiber is arranged in the spiral metal protection tube in a penetrating mode, high-heat-conduction nano silicone grease is filled between the inner wall of the spiral metal protection tube and the temperature measuring optical fiber, heat conduction efficiency is improved, spiral micro grooves are formed in the outer wall of the spiral metal protection tube, a plurality of conductor copper wires are embedded in the spiral micro grooves, and mechanical engagement and heat conduction contact area between the spiral metal protection tube and the conductor