Environment-friendly flame-retardant cable

Abstract

The utility model discloses an environment-friendly flame-retardant cable, which comprises a cable core and a sheath used for wrapping the cable core, the cable core comprises a plurality of wire cores and a cooling pipeline, the cooling pipeline is arranged at the center of the cable core, and the plurality of wire cores are symmetrically arranged around the cooling pipeline at the center of the cable core. The structure of each wire core is provided with a conductor, a wrapping tape, an insulating layer and a waterproof layer in sequence from inside to outside, and the sheath is provided with an inner protection layer, a metal wire armor and an outer protection layer in sequence from inside to outside. The cable is reasonable in structural design, and has the following beneficial effects that the cable core comprises the three wire cores and the cooling pipeline, the cooling pipeline is arranged at the center of the cable core, and the plurality of wire cores are symmetrically arranged around the cooling pipeline at the center of the cable core, so that the cooling pipeline can effectively cool the wire cores; and the temperature of the conductor can be rapidly cooled to be below-18 DEG C, so that the conductor is prevented from working at high temperature to damage an insulating layer, and the insulating effect of the insulating layer is kept.

Description

Technical Field

[0001] The utility model relates to the technical field of cables, in particular to an environmentally friendly flame-retardant cable. Background Art

[0002] With the rapid development of my country's economy, the demand for high-temperature cables in special industries has shown a rapid growth stage. The market demand for heat-resistant and high-temperature cables is growing at an annual rate of 20%. As an important component of special cables, high-temperature resistant cables have extremely strong vitality and are in short supply. For this reason, my country needs to import about 2 billion yuan of high-temperature resistant cables from abroad for domestic construction every year.

[0003] Generally speaking, cables can be used for mass production because of the low cost of plastics and rubber, and plastics and rubber are the main raw materials for the insulation sheath of wires and cables. However, for some special industries such as petrochemicals, steel, aerospace, shipbuilding, military industry, pharmaceuticals, food, plastic machinery, boilers and other industries related to heat and high temperature, these special fields require that all supporting facilities can operate normally at high temperatures. Among all the supporting equipment, the most important non-high temperature resistant wires and cables are none other than high temperature resistant wires and cables. Only by equipping with high temperature resistant wires and cables can the normal power supply be ensured. During the current use process, the cables are prone to the following problems: 1. In a high temperature working environment, the electrical performance of the cables is often affected by the cables' inability to withstand high temperatures, thereby affecting the normal use of the cables. 2. The cables have poor anti-aging performance and short service life. 3. The flame retardant and fireproof properties are poor, which can easily lead to loss of life and property in the event of a fire. Therefore, it is urgent to develop a cable that can be used in high temperature places and cope with strong fires. Utility Model Content

[0004] The utility model aims to provide a cable which can be used in high temperature places and can cope with strong fire.

[0005] In order to achieve the above-mentioned purpose, the technical solution of the utility model provides an environmentally friendly flame-retardant cable, including a cable core and a sheath for wrapping the cable core, the cable core includes a plurality of wire cores and a cooling pipe, the cooling pipe is arranged at the center of the cable core, and the plurality of wire cores are symmetrically arranged around the cooling pipe in the center of the cable core, the structure of the wire core is provided with a conductor, a wrapping tape, an insulating layer, and a waterproof layer in sequence from the inside to the outside, and the sheath is provided with an inner protective layer, a metal wire armor, and an outer protective layer in sequence from the inside to the outside.

[0006] Furthermore, the number of the wire cores is 3; the cable core is produced by extrusion, and during the extrusion production, the gaps between the wire cores and between the wire cores and the cooling pipes are filled with plastic.

[0007] Furthermore, the conductor is the second type of conductor in the national standard GB / T 3956-2008.

[0008] Furthermore, the wrapping tape is two layers of calcined mica tapes wrapped in an overlapping manner, and the wrapping overlap rate is 50-55%.

[0009] Furthermore, the insulating layer is a PEEK plastic layer, and the thickness of the PEEK plastic layer is 0.15-0.25 mm.

[0010] Furthermore, the waterproof layer is a longitudinally wrapped aluminum-plastic composite tape.

[0011] Furthermore, a drainage line with a diameter of 0.15 mm is also provided in the waterproof layer.

[0012] Furthermore, the cooling pipeline is an austenitic stainless steel pipeline, and a coolant flows through the cooling pipeline, and the coolant is liquid nitrogen.

[0013] Furthermore, the inner protective layer is a polypropylene PP insulation layer, and the outer protective layer is a flame retardant polyurethane PUR layer.

[0014] Furthermore, the metal wire armor is aluminum alloy wire armor.

[0015] In summary, the device structure of the utility model is reasonably designed, and the use of the technical solution of the utility model has the following beneficial effects: the cable core includes 3 wire cores and a cooling pipe, the cooling pipe is arranged at the center of the cable core, and several of the wire cores are symmetrically arranged around the cooling pipe in the center of the cable core. This arrangement enables the cooling pipe to effectively cool the wire core, and can quickly cool the conductor temperature to below -18°C, thereby preventing the conductor from working at high temperature and damaging the insulation layer, and maintaining the insulating effect of the insulation layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the cross-sectional structure of the utility model environmentally friendly flame-retardant cable;

[0017] Explanation of the reference numerals: 1- conductor; 2- tape; 3- insulation layer; 4- waterproof layer; 5- cooling pipe; 6- inner protective layer; 7- metal wire armor; 8- outer protective layer. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention, but this does not constitute a limitation on the protection scope of the present invention.

[0019] In the present invention, for a clearer description, the following explanation is made: the observer faces the attached Figure 1For observation, the left front side of the observer is set as the front, the right rear side of the observer is set as the rear, the left rear side of the observer is set as the left, the right front side of the observer is set as the right, the top of the observer is set as the top, and the bottom of the observer is set as the bottom. It should be pointed out that the terms "front end", "rear end", "left side", "right side", "middle", "top", "bottom" and the like in the text indicate the orientation or position relationship based on the orientation or position relationship set in the drawings, which is only for the convenience of clearly describing the utility model, and does not indicate or imply that the structure or component referred to must have a specific orientation or be constructed in a specific orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third", and "fourth" are only used for the purpose of clarifying or simplifying the description, and cannot be understood as indicating or implying relative importance or quantity.

[0020] The core of the cable is mainly composed of two parts: one is the conductor and the other is the insulator. The function of the conductor is to conduct current, so the conductor will heat up, and the greater the current, the greater the heat (the heat generation is proportional to the square of the current). The insulator itself does not heat up, but the insulator is wrapped outside the conductor, and the heat generated by the conductor will be transferred to the insulator, causing the insulator temperature to rise.

[0021] Conductors are made of metal, so they can withstand high temperatures. An ambient temperature of 200 degrees will not affect copper and aluminum conductors. However, insulators are made of organic matter and are not resistant to high temperatures. An ambient temperature of 200 degrees will damage the insulators.

[0022] Therefore, in order to prevent the insulation of the cable from being damaged by high temperature, it is necessary to control the heat generated by the conductor, that is, to control the temperature of the conductor. In practical applications, if the working temperature of the cable conductor is kept at 90 degrees for a long time, it will not cause additional damage to the insulation material of the cable (but normal loss will still exist). Of course, this 90 degrees is not absolute. The loss caused by a short-term exceeding 90 degrees is not large. Of course, the life of the cable will be shortened a little. On the contrary, if the working temperature is lower than 90 degrees for a long time, the service life of the cable will be extended accordingly. Therefore, it is necessary to reduce the working temperature of the cable conductor as much as possible to extend the working life of the cable.

[0023] In short, semiconductor cooling technology is very important, which can improve the performance and life of semiconductor devices. Different cooling technologies have different advantages and disadvantages, and the appropriate technology needs to be selected according to the specific situation. In the future, with the continuous development of science and technology, semiconductor cooling technology will continue to innovate and progress.

[0024] See also Figure 1The utility model provides an environmentally friendly flame-retardant cable, including a cable core and a sheath for wrapping the cable core. The cable core includes a plurality of wire cores and a cooling pipe 5. The cooling pipe 5 is arranged at the center of the cable core. The plurality of wire cores are symmetrically arranged around the cooling pipe 5 in the center of the cable core. The structure of the wire core is provided with a conductor 1, a wrapping tape 2, an insulating layer 3, and a waterproof layer 4 in sequence from the inside to the outside. The sheath is provided with an inner protective layer 6, a metal wire armor 7, and an outer protective layer 8 in sequence from the inside to the outside.

[0025] As a preferred embodiment of the present invention, the number of the wire cores is 3; the cable core is produced by extrusion, and during the extrusion production, the gaps between the wire cores and between the wire cores and the cooling pipe 5 are filled with plastic.

[0026] Specifically, the conductor 1 is the second type of conductor in the national standard GB / T 3956-2008, and the tape 2 is two layers of calcined mica tapes wrapped in an overlapping manner, with the wrapping overlap rate being 50-55%.

[0027] Conductor 1 is wrapped with two layers of calcined mica tapes, and the mica tape wrapping overlap rate is 50-55%. The calcined mica tape has excellent high temperature resistance, which can reach the A-level fire resistance level (950-1000°C), and the calcined mica tape has a temperature resistance of more than 1000°C. At a temperature of 850-1000°C and a voltage of 600-1000V, it can ensure that the cable will not be broken down within 90 minutes. At the same time, the thermal expansion coefficient is small, and there is no obvious powdery scattering and cracking at high temperature.

[0028] Specifically, the insulating layer 3 is a PEEK plastic layer, and the thickness of the PEEK plastic layer is 0.15-0.25 mm; the waterproof layer 4 is a longitudinally wrapped aluminum-plastic composite tape, and a drainage line with a diameter of 0.15 mm is also arranged in the waterproof layer 4.

[0029] After the conductor 1 is wrapped with mica tape, a layer of PEEK plastic with a thickness of 0.15-0.25mm is extruded outside the mica tape; the extrusion temperature of PEEK plastic is high, generally above 350℃, and it cannot be processed by an extruder of ordinary structure, and it needs to be processed by a high-temperature plastic extruder. PEEK (polyetheretherketone) has excellent comprehensive properties: such as high mechanical strength, high temperature resistance, impact resistance, flame retardancy, acid and alkali resistance, hydrolysis resistance, wear resistance, fatigue resistance, radiation resistance and good electrical properties. It is also an environmentally friendly material: non-toxic, low smoke when burning, good physiological compatibility, etc. It is usually used in the form of reinforced plastics for processing products.

[0030] A layer of aluminum-plastic composite tape is longitudinally wrapped outside the extruded PEEK plastic layer, and a 0.15 drainage line is added in the aluminum-plastic composite tape, where the drainage line is set to monitor the temperature of the insulation surface. The aluminum-plastic composite tape has good processing performance, its texture is soft, has good bending properties, and has high tensile strength; it also has excellent moisture-proof and waterproof functions. After the plastic layer is heated, it melts and self-adheses without gaps, preventing the entry of water vapor and water droplets; at the same time, the aluminum-plastic composite tape contains a metal layer, which can shield the surrounding electromagnetic interference.

[0031] As a preferred embodiment of the present invention, the cooling pipe 5 is an austenitic stainless steel pipe, and a coolant flows through the cooling pipe 5, and the coolant is liquid nitrogen.

[0032] The cooling pipeline 5 adopts a liquid nitrogen liquid supply distributor, which is an important component in the liquid nitrogen refrigeration system. Its function is to evenly distribute the liquid nitrogen in the liquid storage tank to different freezer groups, and can monitor the technical parameters such as the pressure flow of the system, and reasonably control the liquid supply of the freezer group and the development, strength and shape of the frozen soil body structure in combination with valve fittings. The liquid nitrogen distributor can be made on site, using austenitic stainless steel 06Cr18N i 10T i material (GB / T20878), welded connection. According to the size of the liquid nitrogen flow, the pipe diameter is selected from 159-273mm and the wall thickness is 3-5mm.

[0033] Conductor 1 is cooled using liquid nitrogen as a coolant. The temperature of liquid nitrogen is very low, reaching -196°C. Its cooling speed is very fast, and it can quickly cool the temperature of conductor 1 to below -18°C, thereby preventing conductor 1 from damaging insulation layer 3 when working at high temperature, and maintaining the insulation effect of insulation layer 3. At the same time, liquid nitrogen also has a sterilizing effect and is pollution-free to the environment. Therefore, liquid nitrogen quick freezing has become an indispensable technology in cables. Liquid nitrogen cooling is an efficient semiconductor cooling technology that uses the low temperature of liquid nitrogen to reduce the temperature of semiconductor devices. The advantage of liquid nitrogen cooling is that the cooling effect is very good.

[0034] Specifically, the inner protective layer 6 is a polypropylene PP insulation layer, the outer protective layer 8 is a flame retardant polyurethane PUR layer, and the metal wire armor 7 is an aluminum alloy wire armor.

[0035] The inner protective layer 6 is produced by extrusion. The material of the inner protective layer 6 is polypropylene PP insulation material. Polypropylene PP insulation material can make the cable resistant to high temperatures up to 140℃ and low temperatures up to -30℃. It has the characteristics of low density, light weight, high volume resistivity, thin wall, smaller cable bending radius, strong resistance to bending fatigue, halogen-free, and more environmentally friendly. The production speed is controlled at 23m / min, the extrusion temperature of the fuselage is 185±5℃, and the extrusion temperature of the die is 208±5℃, otherwise it may affect the product appearance quality and the electrical and mechanical properties of the insulation layer.

[0036] Metal wire armor 7 uses aluminum alloy wire armor; the armoring equipment needs to use a detwisting device, otherwise the metal wire will have a large internal stress, which may easily lead to wire jumping, unravelling, twisting and other undesirable situations. The number of steel wires before armoring needs to be calculated. Too few wires will lead to large gaps between the metal wires and uneven force when subjected to external tension; too many wires will lead to the metal wires not being able to be arranged and the internal stress between the metal wires will be large. In addition, the pitch size of the metal wire also affects the product quality. If the pitch is too small, the internal stress of the metal wire will be large, causing the metal wire or the wire core to twist; if the pitch is too large, the metal wire will be loose and the wire core will not be able to withstand tension.

[0037] The outer protective layer 8 is made of flame-retardant polyurethane PUR, which makes the cable high temperature resistance level reach 250 degrees and low temperature resistance -60 degrees, and has excellent characteristics such as high cold resistance, high temperature resistance, corrosion resistance, weather resistance, acid and alkali resistance, and environmental protection. The outer protective layer 8 is produced by extrusion, and the speed is controlled within 15 m / min during production. Too fast production speed will lead to high extrusion pressure and unstable sheath core eccentricity. The extrusion temperature of the fuselage is 195±5℃, and the extrusion temperature of the head is 208±5℃, otherwise it may affect the appearance quality of the product and the electrical and mechanical properties of the sheath layer. Flame-retardant polyurethane PUR is a power cable sheath material with good electrical insulation and fire resistance. It is made of flame-retardant rubber and has the characteristics of self-extinguishing, anti-aging, anti-corrosion, oil resistance and ozone resistance. The flame-retardant polyurethane PUR sheath can be used for a long time in outdoor environments and humid environments, and can withstand high mechanical pressure, and has good wear resistance and tensile strength. As an important power cable sheath material, flame retardant polyurethane PUR sheath has the advantages of fire resistance, oil resistance, wear resistance, high tensile strength, etc., and is suitable for cable protection in various industrial environments. When choosing rubber insulation flame retardant sheath products, you should choose the material and specifications that suit you according to your specific needs.

[0038] The outer protective layer of the existing cable is mostly extruded with polyvinyl chloride (PVC), while the outer protective layer 8 of the utility model is made of flame-retardant polyurethane PUR sheath material, which has the characteristics of flame retardancy, oil resistance, acid and alkali resistance, hydrolysis resistance, UV resistance, low temperature resistance, wear resistance, etc. It effectively solves the environmental protection requirements of cable flexibility, rat bite resistance, drag resistance, high and low temperature resistance, waterproof and moisture resistance under multi-environment and multi-site use, as well as the current low-smoke halogen-free flame retardancy.

[0039] The insulating layer 3 of the utility model is a PEEK plastic layer. PEEK (polyetheretherketone) has excellent comprehensive properties, such as high mechanical strength, high temperature resistance, impact resistance, flame retardancy, acid and alkali resistance, hydrolysis resistance, wear resistance, fatigue resistance, radiation resistance and good electrical properties. It is also an environmentally friendly material: non-toxic, low smoke when burning, good physiological compatibility, etc. It is usually used in the form of reinforced plastics for processing products.

[0040] ① High temperature resistance: glass transition temperature is 143℃, melting point is 334℃, heat deformation temperature (1.82MPa) is 152℃, continuous use temperature is 240℃, short-term use temperature is 300℃. At the same time, PEEK is the best steam-resistant variety among all engineering plastics and can work in steam above 200℃ and pressurized hot water at 300℃.

[0041] ② Flame retardancy: It has self-extinguishing properties, oxygen index OI value> 24%, and the sample with a friction density of 0.8-1.5mm without adding flame retardant can also reach the UL94 V-0 level. The smoke volume is very small when forced to burn, and the smoke does not contain toxic gas. The smoke degree is much smaller than PC, PSF, PTFE, PF and PES;

[0042] ③ Mechanical properties: It has high strength and modulus. At 200℃, its tensile strength can still reach 50MPa, and its bending elastic modulus can reach 15GPa. It has excellent creep resistance, fatigue resistance and impact resistance, and is the best among most engineering plastics. Its impact strength can reach 70-100J / m;

[0043] ④Electrical properties: PEEK is a low-polarity polymer with good electrical insulation, small dielectric constant and dielectric loss factor, and medium dielectric strength. Its volume resistivity is greater than 101Ω·cm, and it still has good dielectric properties in the high-frequency range. The dielectric constant remains 3.2 to 3.3 in the range of 60Hz to 104Hz;

[0044] ⑤ Corrosion resistance and weather resistance: It has excellent corrosion resistance. Except for concentrated sulfuric acid, it can resist almost any chemical reagents and most common organic solvents, and can maintain good corrosion resistance even at higher temperatures. PEEK has strong radiation resistance and is the best radiation-resistant variety among engineering plastics, better than PS with excellent radiation resistance. It will only become brittle after absorbing (1.0-1.2)×107Gy of γ-ray irradiation, and (0.1-12)×106Gy of β-ray irradiation has no effect on it.

[0045] The use of PEEK plastic as a reinforcement layer coated on the outside of the fire-resistant mica tape greatly ensures the fire resistance and insulation performance of the product. The product is not affected when used in harsh environments: such as high temperature and humidity, vibration and impact, radiation, acid and alkali corrosion, etc.

[0046] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the protection scope of the present invention.

Claims

1. An environmentally friendly flame-retardant cable, comprising a cable core and a sheath for wrapping the cable core, characterized in that: The cable core includes a plurality of wire cores and a cooling pipe, the cooling pipe is arranged at the center of the cable core, and the plurality of wire cores are symmetrically arranged around the cooling pipe in the center of the cable core. The structure of the wire core is provided with a conductor, a wrapping tape, an insulating layer, and a waterproof layer in sequence from the inside to the outside, and the sheath is provided with an inner protective layer, a metal wire armor, and an outer protective layer in sequence from the inside to the outside.

2. An environmentally friendly flame-retardant cable according to claim 1, characterized in that: The number of the wire cores is 3; the cable core is produced by extrusion, and during the extrusion production, the gaps between the wire cores and between the wire cores and the cooling pipes are filled with plastic.

3. An environmentally friendly flame-retardant cable according to claim 1 or 2, characterized in that: The conductor is the second type of conductor in the national standard GB / T 3956-2008.

4. An environmentally friendly flame-retardant cable according to claim 3, characterized in that: The wrapping tape is two layers of calcined mica tapes wrapped in an overlapping manner, and the wrapping overlap rate is 50-55%.

5. An environmentally friendly flame-retardant cable according to claim 4, characterized in that: The insulating layer is a PEEK plastic layer, and the thickness of the PEEK plastic layer is 0.15-0.25 mm.

6. The environmentally friendly flame-retardant cable according to claim 5, characterized in that: The waterproof layer is a longitudinally wrapped aluminum-plastic composite tape.

7. An environmentally friendly flame-retardant cable according to claim 6, characterized in that: A drainage line with a diameter of 0.15 mm is also arranged in the waterproof layer.

8. An environmentally friendly flame-retardant cable according to claim 1 or 7, characterized in that: The cooling pipeline is an austenitic stainless steel pipeline, and a coolant flows through the cooling pipeline, and the coolant is liquid nitrogen.

9. The environmentally friendly flame-retardant cable according to claim 1, characterized in that: The inner protective layer is a polypropylene PP insulating layer, and the outer protective layer is a flame retardant polyurethane PUR layer.

10. The environmentally friendly flame-retardant cable according to claim 1, characterized in that: The metal wire armor is aluminum alloy wire armor.

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