Novel intelligent early-warning fire-resistant medium-voltage cable and preparation method thereof

Abstract

The invention provides a novel intelligent early-warning fire-resistant medium-voltage cable and a preparation method thereof, and the cable comprises a cable core which comprises a conductor which is formed by compressing and twisting a plurality of annealed soft copper wires; the communication optical cable and the temperature measuring optical cable are arranged in the cable core, the temperature measuring optical cable is used for collecting whole-line temperature signals of the cable in real time, and the communication optical cable is used for receiving the whole-line temperature signals of the cable collected by the temperature measuring optical cable in real time, converting the signals into optical signals and transmitting the optical signals to a control terminal; the control terminal analyzes the received temperature data and controls the working state of the early warning device. The fireproof structure is arranged on the outer side of the cable core; the protective layer structure is arranged on the outer side of the fireproof structure; real-time monitoring, transmission and early warning of fire temperature signals are achieved through the optical cable communication technology, meanwhile, the continuous power supply and information transmission capacity of the cable in the fire high-temperature environment is ensured, precious time is won for rescue, and the use safety of the cable is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cables, in particular to a novel intelligent early warning fire-resistant medium voltage cable and a preparation method thereof. BACKGROUND

[0002] As the core power transmission and distribution carrier in urban power grids and industrial power supply fields, the safe operation of medium voltage power cables is directly related to the stability of the power system and public safety. However, the traditional medium voltage cables have the following technical defects in fire scenarios: Fire warning lag: existing cables lack real-time temperature monitoring and information transmission functions, and temperature anomalies in the early stage of fire are difficult to discover in time, relying on external fire fighting systems or manual inspection, resulting in delayed fire confirmation and missed best rescue opportunity.

[0003] Fire resistance and communication are separated: although conventional fire-resistant cables have certain flame retardant ability, they can only maintain power transmission for a short time (such as 30-40 minutes) during a fire, and cannot transmit fire data synchronously, making it difficult for rescue personnel to obtain key information such as cable temperature distribution, affecting decision-making efficiency.

[0004] Insufficient information transmission reliability: if traditional cables use electrical signals to transmit temperature data, they are easily affected by electromagnetic interference or line melting during a fire, resulting in signal interruption and inability to provide continuous and stable fire feedback to remote control terminals.

[0005] In the prior art, some cables attempt to integrate temperature measuring elements (such as thermocouples or optical fiber sensors), but have the following limitations: The temperature measuring element is not tightly combined with the cable body and is easily damaged by high temperatures in a fire; The communication method relies mainly on wired electrical signal transmission, which has weak anti-interference ability; There is no intelligent analysis module to realize real-time processing and early warning linkage of temperature data.

[0006] The disclosure of the above background art content is only used to assist in understanding the inventive concept and technical solutions of the present application, and it does not necessarily belong to the prior art of the present patent application, nor does it necessarily provide technical teaching; there is no clear evidence that the above application is novel and creative. SUMMARY

[0007] To solve the above technical problems, the present application proposes a novel intelligent early warning fire-resistant medium voltage cable and a preparation method thereof, which realizes real-time monitoring, transmission and early warning of fire temperature signals through optical cable communication technology, while ensuring the continuous power supply and information transmission ability of the cable in a high temperature fire environment, gaining valuable time for rescue and improving the safety of cable use.

[0008] In order to achieve the above purpose, the technical scheme of the present application is as follows: In one aspect, the present application provides a new intelligent early warning fire-resistant medium voltage cable, comprising: A cable core, comprising: a conductor, which is tightly stranded by a plurality of annealed soft copper wires; A communication optical cable and a temperature measuring optical cable arranged in the cable core, the temperature measuring optical cable is used for collecting real-time cable temperature signals, the communication optical cable is used for receiving the real-time cable temperature signals collected by the temperature measuring optical cable and converting the signals into optical signals transmitted to a control terminal, the control terminal analyzes the received temperature data and controls the working state of the early warning device; A fire-resistant structure arranged outside the cable core; A sheath structure arranged outside the fire-resistant structure.

[0009] The present application provides a new intelligent early warning fire-resistant medium voltage cable and a preparation method thereof, which realizes real-time monitoring, transmission and early warning of fire temperature signals through optical cable communication technology, ensures the continuous power supply and information transmission capability of the cable under high temperature fire environment, saves valuable time for rescue, and improves the safety of cable use.

[0010] As a preferred technical solution, the fire-resistant structure comprises: A first fire-resistant layer, which is a ceramicized low-smoke halogen-free polyolefin oxygen barrier material layer; A second fire-resistant layer, which is wrapped outside the first fire-resistant layer and formed by wrapping glass fiber tape and mica tape.

[0011] As a preferred technical solution, the cable core further comprises: An insulation structure, which is wrapped outside the conductor and comprises an inner shielding layer, an insulation layer and an outer shielding layer arranged in sequence from inside to outside; A filler, which is filled in the gap between the insulation structure and the conductor; A wrapping layer, which is wrapped outside the insulation structure and the filler, and comprises a glass fiber tape layer and a silica aerogel thermal insulation felt thermal insulation layer arranged in sequence from inside to outside.

[0012] As a preferred technical solution, the thickness ratio of the insulation structure to the first fire-resistant layer is 1: (1.1-1.3).

[0013] As a preferred technical solution, the inner shielding layer is a cross-linked semi-conductive conductor shielding layer, the insulation layer is a cross-linked polyethylene layer, the outer shielding layer is a cross-linked peelable semi-conductive insulation shielding layer, and the filler is a non-hygroscopic strand glass fiber rope.

[0014] As a preferred technical solution, the sheath structure comprises: An armor layer; an armored protection structure wrapped outside the armored layer; an outer sheath wrapped outside the armored protection structure.

[0015] As a preferred technical solution, the sheath structure comprises: an armored layer, an armored protection structure wrapped outside the armored layer; an outer sheath wrapped outside the armored protection structure.

[0016] As a preferred technical solution, the armored layer is a galvanized steel strip armored layer, the armored protection structure comprises a synthetic mica tape layer and a glass fiber tape layer arranged in sequence from inside to outside, and the outer sheath is a ceramicized low-smoke halogen-free polyolefin outer sheath.

[0017] In another aspect, the present application provides a preparation method of a new type of intelligent early warning fire-resistant medium voltage cable, and the new type of intelligent early warning fire-resistant medium voltage cable is prepared by the method, and the method comprises the following steps: S1, preparing a cable core, comprising the following steps: S101, preparing a conductor by annealing and tightly twisting copper wires to form the conductor; S2, introducing a communication optical cable and a temperature measurement optical cable into the cable core; S3, preparing a fire-resistant structure outside the cable core; S4, preparing a sheath structure outside the fire-resistant structure.

[0018] As a preferred technical solution, step S1 of preparing a cable core further comprises the following steps: S102, forming an insulation structure outside the conductor, and the insulation structure is formed by adopting a three-layer co-extrusion process of a cross-linked semi-conductive conductor shielding material, a cross-linked polyethylene material and a cross-linked semi-conductive insulation shielding material to form an inner shielding layer, an insulation layer and an outer shielding layer at one time; S103, filling a non-hygroscopic strand glass fiber rope in the gap between the conductor and the insulation structure to form a filling body; S104, wrapping at least two layers of glass fiber tape outside the filling body, and then wrapping two layers of silica aerogel thermal insulation felt to form a wrapping layer; Step S3 of preparing a fire-resistant structure outside the cable core comprises the following steps: S301, extruding and wrapping a ceramicized low-smoke halogen-free polyolefin oxygen barrier material outside the cable core to form a first fire-resistant layer; S302, wrapping at least two layers of glass fiber tape outside the first fire-resistant layer, and then wrapping at least two layers of synthetic mica tape to form a second fire-resistant layer.

[0019] As a preferred technical solution, step S4 prepares a protective layer structure on the outer side of the refractory structure, including the following steps: S401 at least two layers of galvanized steel belts are wrapped around the outer side of the refractory structure to form an armored layer; S402 at least two layers of composite mica belts are wrapped around the outer side of the armored layer, and at least two layers of glass fiber belts are wrapped around the outer side of the composite mica belts to form an armored protective structure; S403 an outer sheath is formed on the outer side of the armored protective structure by extruding a ceramicized low-smoke halogen-free polyolefin sheath material.

[0020] The present application provides a new type of intelligent early warning fire-resistant medium voltage cable and its preparation method, which has the following beneficial effects: 1) The present application provides a new type of intelligent early warning fire-resistant medium voltage cable and its preparation method, which realizes real-time monitoring, transmission and early warning of fire temperature signals through optical cable communication technology, ensures the continuous power supply and information transmission capability of the cable under high temperature environment, saves valuable time for rescue, and improves the safety of cable use.

[0021] 2) The present application provides a new type of intelligent early warning fire-resistant medium voltage cable and its preparation method, which brings temperature measuring optical cable and communication optical cable into the cable core. When the environmental temperature is abnormal, the optical signal parameters in the temperature measuring optical cable will change, thereby realizing distributed real-time monitoring of the temperature measuring optical cable and the temperature distribution of the cable. This monitoring method is intrinsically safe, not affected by electromagnetic interference, has long monitoring distance and high precision, and the temperature signals collected by the temperature measuring optical cable are transmitted to the control terminal through the communication optical cable. The communication optical cable converts the electrical signal into an optical signal for transmission, effectively avoiding signal attenuation and external interference, ensuring the stability of long-distance data transmission, and the analysis module in the control terminal analyzes and determines the risk. The control terminal will immediately start the early warning device, which will issue an alarm through sound and light alarm, interface prompt and other ways, and build a cable safety protection system integrating real-time monitoring, data transmission, intelligent analysis and active warning. Real-time monitoring, transmission and early warning of fire temperature signals are realized through optical cable communication technology. At the same time, annealed soft copper wire tight pressing and twisting (tight pressing coefficient ≥ 0.9) ensures that the conductor temperature does not exceed the critical value of 250℃ when short-circuiting, improves the thermal stability of the conductor, and forms a ladder type fireproof protection system for the refractory structure, which can effectively block heat transfer and ensure at least 90 minutes of information transmission and power supply function under extreme conditions such as fire, ensuring the continuous power supply and information transmission capability of the cable under high temperature environment, saving valuable time for rescue, and improving the safety of cable use. BRIEF DESCRIPTION OF DRAWINGS

[0022] Fig. 1 The structure diagram of a new type of intelligent early warning fire-resistant medium voltage cable provided by the present application is shown in the figure; Fig. 2This is a structural schematic diagram from another perspective of a novel intelligent early warning fire-resistant medium-voltage cable provided by the present invention; Fig. 3 This is a structural schematic diagram from another perspective of a novel intelligent early warning fire-resistant medium-voltage cable provided by the present invention; Among them, 1-conductor; 2-temperature measuring optical cable; 3-communication optical cable; 4-insulation structure; 5-filler; 6-wrapping layer; 7-first fire-resistant layer; 8-second fire-resistant layer; 9-armor layer; 10-armor protection structure; 11-outer sheath. Detailed Implementation

[0023] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0024] like Figs. 1-3 As shown, this invention provides a novel intelligent early warning fire-resistant medium-voltage cable, comprising: The cable core includes: a conductor 1, which is formed by tightly twisting together multiple annealed soft copper wires; The communication optical cable 3 and the temperature measuring optical cable 2 are installed in the cable core. The temperature measuring optical cable 2 is used to collect the temperature signal of the entire cable in real time. The communication optical cable 3 is used to receive the temperature signal of the entire cable collected in real time by the temperature measuring optical cable 2 and convert it into an optical signal for transmission to the control terminal. The control terminal analyzes the received temperature data and controls the working status of the early warning device. A fire-resistant structure is provided on the outside of the cable core; A protective layer structure is provided on the outside of the fire-resistant structure.

[0025] This invention proposes a novel intelligent early warning fire-resistant medium-voltage cable that uses optical fiber communication technology to achieve real-time monitoring, transmission, and early warning of fire temperature signals. At the same time, it ensures the cable's continuous power supply and information transmission capabilities under high-temperature fire conditions, buying valuable time for rescue and improving the safety of cable use.

[0026] Preferably, the refractory structure comprises: The first refractory layer 7 is a ceramicized low-smoke halogen-free polyolefin oxygen barrier material layer. The second fire-resistant layer 8 covers the outside of the first fire-resistant layer 7 and is formed by wrapping with glass fiber tape and mica tape. The first fire-resistant layer 7 is made of ceramicized low-smoke halogen-free polyolefin material, which forms a continuous fire-resistant barrier through extrusion process. When exposed to fire, it can quickly ceramicize to form a hard shell, stabilize the structure, effectively isolate oxygen and inhibit the spread of flames, and protect the internal key components. Its low-smoke halogen-free characteristics can reduce the release of toxic fumes and meet environmental protection and safety requirements. The second fire-resistant layer 8 is wrapped by glass fiber tape and mica tape, and cooperates with the extruded first fire-resistant layer 7 to build multiple fire-resistant lines of defense, thereby improving the tolerance of the cable under extreme fire conditions. The first fire-resistant layer 7 is preferably a layer of ceramicized low-smoke halogen-free polyolefin oxygen barrier material, which forms a rigid ceramic layer in a fire, and the flexible wrapping of the glass fiber tape of the second fire-resistant layer 8 forms a “rigid-flexible combination” structure, thereby avoiding cracking or falling of the material at high temperatures, and further ensuring that the cable maintains stable function for at least 90 minutes. Meanwhile, the oxygen barrier property of the first fire-resistant layer 7 and the physical barrier of the second fire-resistant layer 8 are complementary, which together improves the fire resistance limit of the cable (such as reaching the B1 level requirement of GB / T 31247), while reducing the heat release rate to gain time for rescue.

[0027] Preferably, the cable core further comprises: An insulation structure 4 wrapped outside the conductor 1, the insulation structure 4 comprising, from inside to outside, an inner shielding layer, an insulation layer, and an outer shielding layer; A filler 5 filled in the gap between the insulation structure 4 and the conductor 1; A wrapping layer 6 wrapped outside the insulation structure 4 and the filler 5, the wrapping layer 6 comprising, from inside to outside, a glass fiber tape layer and a silica aerogel thermal insulation felt thermal insulation layer; The insulation structure 4 prevents current leakage, withstands medium voltage operating voltage, insulates the conductor from other components, ensures that electrical energy is only transmitted along the conductor, and ensures electrical safety; The filler 5 fills the gaps between the components inside the cable core, making the overall structure compact and round, avoiding uneven stress on the components, and also serving as a buffer and moisture-proof function; The wrapping layer 6 has a double thermal insulation function, the glass fiber tape layer provides mechanical support and high temperature resistance (short-term temperature resistance up to 1400℃), and delays the invasion of fire; the silica aerogel thermal insulation felt forms a high-efficiency thermal insulation barrier by utilizing its ultra-low thermal conductivity (<0.02 W / m·K), thereby reducing the impact of high temperature on the cable core; the wrapping layer 6 wraps and fixes the internal insulation structure, optical cable and other components, enhances the structural integrity of the whole structure, prevents displacement of each layer, and also has certain insulation and protection auxiliary functions; through the multi-layer design of “electric field optimization-insulation protection-high temperature insulation-mechanical reinforcement”, the electrical performance, fire resistance and structural stability are comprehensively improved.

[0028] As a preferred technical solution, the thickness ratio of the insulation structure 4 to the first fire-resistant layer 7 is 1:(1.1-1.3); the thickness ratio of the insulation structure 4 to the first fire-resistant layer 7 is preferably 1:1.1, 1:1.2, or 1:1.3, and the specific point values included in the protection scope of the present application are not listed due to the length of the article and the consideration of simplicity; the difference in the thermal expansion coefficient of the insulation structure 4 and the first fire-resistant layer 7 is large, and through the thickness ratio of 1:(1.1-1.3), the difference in the expansion rate of the materials at high temperature can be compensated for, avoiding interlayer debonding or cracking; the slightly thicker (10%-30%) first fire-resistant layer 7 can enhance its high-temperature porcelainization capability, forming a more stable ceramic oxygen barrier, while avoiding excessive thickness leading to excessive overall diameter of the cable, affecting the laying flexibility.

[0029] Preferably, the inner shielding layer is a cross-linked semi-conductive conductor shielding layer, the insulation layer is a cross-linked polyethylene layer, the outer shielding layer is a cross-linked peelable semi-conductive insulation shielding layer, and the filling body 5 is a non-hygroscopic strand glass fiber rope; The inner shielding layer is preferably a cross-linked semi-conductive conductor shielding layer, which is composed of semi-conductive cross-linked polyethylene, tightly combined with the insulation layer through a three-layer co-extrusion process, eliminating conductor surface burrs or protrusions, uniform electric field distribution and suppressing partial discharge, and the cross-linked design avoids material flow at high temperature, ensuring long-term stability; The insulation layer is preferably a cross-linked polyethylene layer, which is composed of cross-linked polyethylene (XLPE) material, has high dielectric strength and heat resistance, blocks current leakage and withstands rated voltage; The outer shielding layer is preferably a cross-linked peelable semi-conductive insulation shielding layer, which further balances the electric field, and the peelable design facilitates post-construction peeling, avoiding the impact of residual insulation performance; The filling body 5 is preferably a non-hygroscopic strand glass fiber rope, which fills the gap between the cable cores, prevents the cores from loosening, and enhances the compression strength; the non-hygroscopic property avoids water penetration and reduces the risk of water aging.

[0030] Preferably, the sheath structure comprises: an armor layer 9, an armored protection structure 10 covering the outer side of the armor layer 9; an outer sheath 11 covering the outer side of the armored protection structure 10; This structure realizes anti-external force impact, high-temperature continuous power supply, and low-smoke safety protection through the multi-layer design of "mechanical protection-fire-resistant heat insulation-environmental protection flame retardation", prolonging the service life of the cable.

[0031] Preferably, the armor layer 9 is a galvanized steel strip armor layer, the armored protection structure 10 comprises a synthetic mica tape layer and a glass fiber tape layer arranged in turn from inside to outside, and the outer sheath 11 is a ceramicized low-smoke halogen-free polyolefin outer sheath; The armored layer 9 is preferably a galvanized steel strip armor layer, which greatly enhances the mechanical protection performance of the cable, resists external extrusion, impact, stretching and other mechanical damage, and is suitable for complex laying environment. The armored protection structure 10 comprises a synthetic mica tape layer and a glass fiber tape layer arranged in turn from inside to outside, the synthetic mica tape layer is converted into a ceramicized fire-resistant layer at high temperature (>650℃), maintains the integrity of the conductor structure, ensures continuous power supply during fire, the glass fiber tape layer enhances the mechanical strength and is resistant to high temperature (short-term 1400℃), forms a composite fire-resistant barrier with the mica tape, protects the armored layer 9 from external corrosion (such as moisture and chemicals), prolongs the service life of the armored layer 9, and improves the fire resistance.

[0032] The outer sheath 11 is preferably a ceramicized low-smoke halogen-free polyolefin outer sheath, which is the outermost protective layer of the cable, resists external environmental erosion such as moisture, chemical corrosion and mechanical friction, comprehensively protects all internal components, and simultaneously sinters into a ceramic dense layer during fire, isolates oxygen and inhibits flame spread; the low-smoke halogen-free property reduces the release of toxic smoke, prolonging the service life of the cable.

[0033] In another aspect, the present application provides a preparation method of a new type of intelligent early warning fire-resistant medium-voltage cable, and the new type of intelligent early warning fire-resistant medium-voltage cable prepared by the method comprises the following steps: S1 preparing a cable core, comprising the following steps: S101 preparing a conductor 1 by annealing and tightly twisting copper wires to form the conductor 1; S2 introducing a communication optical cable 3 and a temperature measurement optical cable 2 into the cable core; S3 preparing a fire-resistant structure outside the cable core; S4 preparing a sheath structure outside the fire-resistant structure.

[0034] The present application provides a preparation method of a new type of intelligent early warning fire-resistant medium-voltage cable, which realizes real-time monitoring, transmission and early warning of fire temperature signals through optical cable communication technology, ensures the continuous power supply and information transmission capability of the cable in a high-temperature fire environment, saves valuable time for rescue, and improves the safety of the cable in use.

[0035] As a preferred technical solution, step S1 of preparing a cable core further comprises the following steps: S102 forming an insulation structure 4 outside the conductor 1, the insulation structure 4 is formed by adopting a cross-linked semi-conductive conductor shielding material, a cross-linked polyethylene material and a cross-linked semi-conductive insulation shielding material to form an inner shielding layer, an insulation layer and an outer shielding layer by a three-layer co-extrusion process at one time; S103 filling a non-hygroscopic strand glass fiber rope in the gap between the conductor 1 and the insulation structure 4 to form a filling body 5; S104 wrapping at least two layers of glass fiber tape outside the filling body 5, and then wrapping two layers of silica aerogel thermal insulation felt to form a wrapping layer 6; Step S3 prepares a fire-resistant structure outside the cable core, including the following steps: S301 extruding a ceramicized low-smoke halogen-free polyolefin oxygen barrier material outside the cable core to form a first fire-resistant layer 7; S302 wrapping at least two layers of glass fiber tape outside the first fire-resistant layer 7, and then wrapping at least two layers of synthetic mica tape to form a second fire-resistant layer 8; In step S102, the cross-linked semi-conductive conductor shielding material is preferably a 10KV cross-linked semi-conductive conductor shielding material; The cross-linked polyethylene material is preferably a 10KV cross-linked polyethylene material; The cross-linked semi-conductive insulation shielding material is preferably a 10KV cross-linked semi-conductive insulation shielding material; The three-layer co-extrusion process at one time in step S102 ensures that there is no interface defect between the layers, improving electrical reliability; This process realizes the overall improvement of electrical performance, mechanical strength and fire resistance through the multi-layer design of "electric field optimization-insulation protection-high temperature insulation-fire resistance".

[0036] Preferably, step S4 prepares a protective layer structure outside the fire-resistant structure, including the following steps: S401 wrapping at least two layers of galvanized steel tape outside the fire-resistant structure to form an armor layer 9; S402 wrapping at least two layers of synthetic mica tape outside the armor layer 9, and then wrapping at least two layers of glass fiber tape to form an armored protection structure 10; S403 extruding a ceramicized low-smoke halogen-free polyolefin sheath material outside the armored protection structure to form an outer sheath; This process realizes the resistance to external force impact, high-temperature continuous power supply and low-smoke safety protection through the multi-layer design of "mechanical protection-fire-resistant insulation-environmental protection-fire resistance", prolonging the service life of the cable.

[0037] The application provides a novel intelligent early warning fire-resistant medium-voltage cable, which comprises three conductors 1, the conductors 1 are tightly pressed and twisted by a plurality of annealed soft copper wires; an insulation structure 4 is wrapped outside the conductors 1, the insulation structure 4 comprises an inner shielding layer, an insulation layer and an outer shielding layer arranged in sequence from inside to outside; a filling body 5 is filled in the gap between the insulation structure 4 and the conductors 1, a wrapping layer 6 is wrapped outside the insulation structure 4 and the filling body 5, the wrapping layer 6 comprises a glass fiber tape layer and a silica aerogel thermal insulation felt heat insulation layer arranged in sequence from inside to outside, the inner shielding layer is a cross-linked semi-conductive conductor shielding layer, the insulation layer is a cross-linked polyethylene layer, the outer shielding layer is a cross-linked peelable semi-conductive insulation shielding layer, and the filling body 5 is a non-hygroscopic strand glass fiber rope; a communication optical cable 3 and a temperature measuring optical cable 2 are arranged in the cable core, the temperature measuring optical cable 2 is used for collecting real-time cable temperature signals, the communication optical cable 3 is used for receiving the real-time cable temperature signals collected by the temperature measuring optical cable 2 and converting the real-time cable temperature signals into optical signals to be transmitted to a control terminal, the control terminal analyzes the received temperature data and controls the working state of an early warning device; a first fire-resistant layer 7 is wrapped outside the wrapping layer 6, the first fire-resistant layer 7 is a ceramicized low-smoke halogen-free polyolefin oxygen barrier material layer; a second fire-resistant layer 8 is wrapped outside the first fire-resistant layer 7, and the second fire-resistant layer 8 is formed by being wrapped by glass fiber tapes and mica tapes, wherein the thickness ratio of the insulation structure 4 to the first fire-resistant layer 7 is 1: (1.1-1.3); an armored layer 9 is wrapped outside the second fire-resistant layer 8, an armored protection structure 10 is wrapped outside the armored layer 9, and an outer sheath 11 is wrapped outside the armored protection structure 10, wherein the armored layer 9 is a galvanized steel tape armored layer, the armored protection structure 10 comprises a synthetic mica tape layer and a glass fiber tape layer arranged in sequence from inside to outside, and the outer sheath 11 is a ceramicized low-smoke halogen-free polyolefin outer sheath; the real-time monitoring, transmission and early warning of fire temperature signals are realized through optical cable communication technology, the continuous power supply and information transmission capability of the cable under a high-temperature fire environment are ensured, valuable time is gained for rescue, and the safety of the cable in use is improved.

[0038] It is to be understood that the present application is described by way of example only, and that modifications or alterations can be made to the features and embodiments described without departing from the spirit and scope of the application. In addition, modifications can be made to the features and embodiments described to adapt them to particular situations and materials without departing from the spirit and scope of the application. Accordingly, the present application is not limited to the specific embodiments described herein, but rather only by the claims which follow, all variations and equivalents which fall within the ranges of the claims being intended to be embraced herein.

Claims

1. A new intelligent early warning fire resistant medium voltage cable, characterized in that, The application relates to a novel intelligent prewarning fireproof medium-voltage cable, which comprises the following steps: A cable core comprises a conductor which is tightly stranded by a plurality of annealed soft copper wires; A communication optical cable and a temperature measuring optical cable are arranged in the cable core, the temperature measuring optical cable is used for collecting temperature signals of the whole cable in real time, the communication optical cable is used for receiving the temperature signals collected by the temperature measuring optical cable and converting the temperature signals into optical signals which are transmitted to a control terminal, the control terminal analyzes the received temperature data and controls the working state of a warning device; A fireproof structure is arranged outside the cable core; A protective layer structure is arranged outside the fireproof structure.

2. The novel intelligent early warning fire resistant medium voltage cable as claimed in claim 1, wherein, The fireproof structure comprises: A first fireproof layer which is a ceramic low-smoke halogen-free polyolefin oxygen barrier material layer; A second fireproof layer which is wrapped outside the first fireproof layer and is formed by wrapping glass fiber belts and mica belts.

3. The novel intelligent early warning fire resistant medium voltage cable as claimed in claim 2, wherein, The cable core further comprises: An insulation structure which is wrapped outside the conductor and comprises an inner shielding layer, an insulation layer and an outer shielding layer which are sequentially arranged from inside to outside; A filling body which is filled in the gap between the insulation structure and the conductor; A wrapping layer which is wrapped outside the insulation structure and the filling body and comprises a glass fiber belt layer and a silica aerogel thermal insulation felt thermal insulation layer which are sequentially arranged from inside to outside.

4. The novel intelligent early warning fire resistant medium voltage cable according to claim 3, characterized in that, The thickness ratio of the insulation structure to the first fireproof layer is 1: (1.1-1.3).

5. The novel intelligent early warning fire resistant medium voltage cable as claimed in claim 3, wherein, The inner shielding layer is a crosslinked semiconductive conductor shielding layer, the insulation layer is a crosslinked polyethylene layer, the outer shielding layer is a crosslinked peelable semiconductive insulation shielding layer, and the filling body is a non-hygroscopic strand glass fiber rope.

6. The novel intelligent early warning fire resistant medium voltage cable as claimed in claim 1, wherein, The protective layer structure comprises: An armor layer; An armor protection structure which is wrapped outside the armor layer; An outer sheath which is wrapped outside the armor protection structure.

7. The novel intelligent early warning fire resistant medium voltage cable as claimed in claim 6, wherein, The armor layer is a galvanized steel belt armor layer, the armor protection structure comprises a synthetic mica belt layer and a glass fiber belt layer which are sequentially arranged from inside to outside, and the outer sheath is a ceramic low-smoke halogen-free polyolefin outer sheath.

8. A method for preparing a new intelligent early warning fire-resistant medium voltage cable, characterized in that, The application further discloses a preparation method of the novel intelligent prewarning fireproof medium-voltage cable. S1 preparing the cable core, comprising the following steps: S101 preparing the conductor, the conductor is prepared by tightly stranding annealed soft copper wires; S2 arranging the communication optical cable and the temperature measuring optical cable in the cable core; S3 preparing the fireproof structure outside the cable core; S4 preparing the protective layer structure outside the fireproof structure.

9. The preparation method of the novel intelligent early warning fire-resistant medium voltage cable according to claim 8, characterized in that, Step S1 further comprises the following steps: S102 forming the insulation structure outside the conductor, the insulation structure is formed by adopting a three-layer co-extrusion process of a crosslinked semiconductive conductor shielding material, a crosslinked polyethylene material and a crosslinked peelable semiconductive insulation shielding material to form the inner shielding layer, the insulation layer and the outer shielding layer; S103 filling the non-hygroscopic strand glass fiber rope in the gap between the conductor and the insulation structure to form the filling body; S104 wrapping at least two layers of glass fiber belts outside the filling body, and then wrapping two layers of silica aerogel thermal insulation felt to form the wrapping layer; Step S3 comprises the following steps: S301 preparing the first fireproof layer outside the cable core; S302 wrapping the second fireproof layer outside the first fireproof layer; and S303 wrapping the armor layer outside the second fireproof layer. S301 extruding ceramic low smoke zero halogen polyolefin oxygen barrier material on the outside of the cable core to form a first fire resistant layer; S302 wrapping at least two layers of glass fiber tape on the outside of the first fire resistant layer, and then wrapping at least two layers of synthetic mica tape to form a second fire resistant layer.

10. The method of preparing a new smart early warning fire resistant medium voltage cable according to claim 8, characterized in that, Step S4 preparing a protective layer structure on the outside of the fire resistant structure, including the following steps: S401 wrapping at least two layers of galvanized steel tape on the outside of the fire resistant structure to form an armor layer; S402 wrapping at least two layers of synthetic mica tape on the outside of the armor layer, and then wrapping at least two layers of glass fiber tape to form an armor protection structure; S403 extruding ceramic low smoke zero halogen polyolefin sheath material on the outside of the armor protection structure to form an outer sheath.

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