Fireproof low-voltage wire

Abstract

The invention relates to the technical field of cables, in particular to a fire-resistant low-voltage wire which comprises a conductor core, an insulating layer, a fire-resistant layer and a sheath layer which are sequentially wrapped from inside to outside. The thickness of the fireproof layer ranges from 0 to the maximum value of the thickness of the fireproof layer, and the maximum value of the thickness of the fireproof layer is obtained through evaluation of a thickness evaluation system. Through the thickness evaluation system, the maximum value of the thickness of the refractory layer is accurately calculated, and the defect that the thickness of the refractory layer depends on experience or fixed value design in the prior art is overcome.

Description

Technical Field

[0001] The invention relates to the technical field of cables, and in particular to a fire-resistant low-voltage electric wire. Background Art

[0002] Fire-resistant wires are specially designed cables. Their main feature is that they can maintain normal electrical performance in high-temperature environments such as fires, and ensure that the power supply to key equipment or systems is not interrupted. Under certain specific conditions, fire-resistant wires need to be buried underground, such as emergency power supply lines or certain special industrial sites (such as chemical plants), which put forward fire-resistant requirements for underground lines.

[0003] The application document with publication number CN204087884U discloses a fire-resistant electric wire, including a conductor and a fire-resistant layer of an inorganic material coated on the conductor.

[0004] The existing technology lacks scientific assessment tools to quantitatively evaluate the thickness of the fire-resistant layer, which makes it difficult to verify the reliability of the product in extreme environments (such as high temperature or fire), and may cause the fire-resistant layer design to be inconsistent with actual needs. Summary of the invention

[0005] The purpose of the present invention is to provide a fire-resistant low-voltage electric wire in view of the above-mentioned shortcomings.

[0006] The present invention adopts the following technical solution:

[0007] A fire-resistant low-voltage electric wire, comprising a conductor core, an insulating layer, a fire-resistant layer and a sheath layer which are sequentially wrapped from the inside to the outside; the thickness of the fire-resistant layer ranges from 0 to a maximum value of the fire-resistant layer thickness, and the maximum value of the fire-resistant layer thickness is obtained by evaluating a thickness evaluation system;

[0008] The thickness assessment system assesses the maximum value of the refractory layer thickness including: obtaining a refractory layer thickness calculation index based on the density of the refractory layer mixed material, the thermal diffusion factor of the refractory layer, the thermal conductivity of the refractory layer, the maximum temperature the refractory layer can withstand, the specific heat capacity of the refractory layer and the pressure resistance factor of the refractory layer; and obtaining the maximum value of the refractory layer thickness based on the refractory layer thickness calculation index and the thickness of the insulating layer.

[0009] Optionally, the thickness assessment system includes an information storage module, a detection module, a control module and a communication module; the information storage module is used to store the maximum temperature that the fire-resistant layer can withstand, the total number of mixed materials that make up the fire-resistant layer and the buried depth of the wire, and transmit them to the control module; the detection module is used to detect and obtain the thickness of the insulating layer, the density of the soil, the density of each mixed material, the volume of each mixed material, the specific heat capacity of the fire-resistant layer and the thermal conductivity of the fire-resistant layer, and transmit them to the control module; the control module obtains the pressure resistance factor of the fire-resistant layer according to the density of the soil and the buried depth of the wire, and obtains the pressure resistance factor of the fire-resistant layer according to the total number of mixed materials that make up the fire-resistant layer, the volume of each mixed material, the specific heat capacity of the fire-resistant layer and the thermal conductivity of the fire-resistant layer. The density of the mixed material of the refractory layer is obtained from the density of the mixed material and the volume of each mixed material; the thermal diffusion factor of the refractory layer is obtained according to the thermal conductivity of the refractory layer, the density of the mixed material of the refractory layer and the specific heat capacity of the refractory layer; the thickness calculation index of the refractory layer is obtained according to the density of the mixed material of the refractory layer, the thermal diffusion factor of the refractory layer, the thermal conductivity of the refractory layer, the maximum temperature that the refractory layer can withstand, the specific heat capacity of the refractory layer and the pressure resistance factor of the refractory layer; the maximum thickness of the refractory layer is obtained according to the thickness calculation index of the refractory layer and the thickness of the insulating layer, and the maximum thickness of the refractory layer is transmitted to the communication module; the communication module transmits the maximum thickness of the refractory layer to the user end.

[0010] Optionally, the detection module includes a thickness detection submodule, a density detection submodule, a volume detection submodule, a specific heat capacity detection submodule and a thermal conductivity detection submodule; the thickness detection submodule is used to detect and obtain the thickness of the insulation layer, and transmit it to the control module; the density detection submodule is used to detect and obtain the density of the soil and the density of each mixed material, and transmit it to the control module; the volume detection submodule is used to detect and obtain the volume of each mixed material, and transmit it to the control module; the specific heat capacity detection submodule is used to detect and obtain the specific heat capacity of the refractory layer, and transmit it to the control module; the thermal conductivity detection submodule is used to detect and obtain the thermal conductivity of the refractory layer, and transmit it to the control module.

[0011] Optionally, the thickness detection submodule includes a shooting unit, a preprocessing unit, an edge detection unit and a thickness calculation unit; the shooting unit is used to shoot and obtain an initial image; the preprocessing unit performs denoising on the initial image; the edge detection unit uses an edge detection algorithm to identify the inner and outer boundaries of the insulating layer; the thickness calculation unit obtains the thickness of the insulating layer according to the inner and outer boundaries of the insulating layer, and transmits it to the control module.

[0012] Optionally, when the control module calculates the maximum value of the thickness of the refractory layer, the following formula is satisfied:

[0013]

[0014] Among them, Tr maxis the maximum value of the fire-resistant layer thickness, jyc is the insulation layer thickness, nhc is the fire-resistant layer thickness calculation index; σ mix is the density of the refractory mixed material, rks is the thermal diffusion factor of the refractory layer, rdl is the thermal conductivity of the refractory layer, temp max is the maximum temperature that the refractory layer can withstand, brr is the specific heat capacity of the refractory layer, and yl is the pressure resistance factor of the refractory layer.

[0015] The beneficial effects achieved by the present invention are:

[0016] 1. The maximum value of the refractory layer thickness can be accurately calculated through the thickness assessment system, avoiding the defects of the traditional technology that the refractory layer thickness depends on experience or fixed value design;

[0017] 2. The thickness assessment system can comprehensively consider multiple influencing factors to optimize the wire design;

[0018] 3. Through the shooting unit, preprocessing unit and edge detection algorithm in the thickness detection submodule, visual detection technology is used to accurately identify the boundary of the insulation layer, automatically calculate the thickness, and improve the detection accuracy and reliability.

[0019] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 It is a structural schematic diagram of the detection module in the present invention;

[0022] Figure 3 It is a structural schematic diagram of the thickness detection submodule in the present invention;

[0023] Figure 4 It is the effect diagram of the present invention;

[0024] Figure 5 This is a rendering of the second embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following is an explanation of the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual dimensions. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0026] Embodiment 1: This embodiment provides a fire-resistant low-voltage wire, combined with Figures 1 to 4 .

[0027] A fire-resistant low-voltage electric wire, comprising a conductor core, an insulating layer, a fire-resistant layer and a sheath layer which are sequentially wrapped from the inside to the outside; the thickness of the fire-resistant layer ranges from 0 to a maximum value of the fire-resistant layer thickness, and the maximum value of the fire-resistant layer thickness is obtained by evaluating a thickness evaluation system;

[0028] The thickness assessment system assesses the maximum value of the refractory layer thickness including: obtaining a refractory layer thickness calculation index based on the density of the refractory layer mixed material, the thermal diffusion factor of the refractory layer, the thermal conductivity of the refractory layer, the maximum temperature the refractory layer can withstand, the specific heat capacity of the refractory layer and the pressure resistance factor of the refractory layer; and obtaining the maximum value of the refractory layer thickness based on the refractory layer thickness calculation index and the thickness of the insulating layer.

[0029] Optionally, the thickness assessment system includes an information storage module, a detection module, a control module and a communication module; the information storage module is used to store the maximum temperature that the fire-resistant layer can withstand, the total number of mixed materials that make up the fire-resistant layer and the buried depth of the wire, and transmit them to the control module; the detection module is used to detect and obtain the thickness of the insulating layer, the density of the soil, the density of each mixed material, the volume of each mixed material, the specific heat capacity of the fire-resistant layer and the thermal conductivity of the fire-resistant layer, and transmit them to the control module; the control module obtains the pressure resistance factor of the fire-resistant layer according to the density of the soil and the buried depth of the wire, and obtains the pressure resistance factor of the fire-resistant layer according to the total number of mixed materials that make up the fire-resistant layer, the volume of each mixed material, the specific heat capacity of the fire-resistant layer and the thermal conductivity of the fire-resistant layer. The density of the mixed material of the refractory layer is obtained from the density of the mixed material and the volume of each mixed material; the thermal diffusion factor of the refractory layer is obtained according to the thermal conductivity of the refractory layer, the density of the mixed material of the refractory layer and the specific heat capacity of the refractory layer; the thickness calculation index of the refractory layer is obtained according to the density of the mixed material of the refractory layer, the thermal diffusion factor of the refractory layer, the thermal conductivity of the refractory layer, the maximum temperature that the refractory layer can withstand, the specific heat capacity of the refractory layer and the pressure resistance factor of the refractory layer; the maximum thickness of the refractory layer is obtained according to the thickness calculation index of the refractory layer and the thickness of the insulating layer, and the maximum thickness of the refractory layer is transmitted to the communication module; the communication module transmits the maximum thickness of the refractory layer to the user end.

[0030] Optionally, the detection module includes a thickness detection submodule, a density detection submodule, a volume detection submodule, a specific heat capacity detection submodule and a thermal conductivity detection submodule; the thickness detection submodule is used to detect and obtain the thickness of the insulation layer, and transmit it to the control module; the density detection submodule is used to detect and obtain the density of the soil and the density of each mixed material, and transmit it to the control module; the volume detection submodule is used to detect and obtain the volume of each mixed material, and transmit it to the control module; the specific heat capacity detection submodule is used to detect and obtain the specific heat capacity of the refractory layer, and transmit it to the control module; the thermal conductivity detection submodule is used to detect and obtain the thermal conductivity of the refractory layer, and transmit it to the control module.

[0031] Optionally, the thickness detection submodule includes a shooting unit, a preprocessing unit, an edge detection unit and a thickness calculation unit; the shooting unit is used to shoot and obtain an initial image; the preprocessing unit performs denoising on the initial image; the edge detection unit uses an edge detection algorithm to identify the inner and outer boundaries of the insulating layer; the thickness calculation unit obtains the thickness of the insulating layer according to the inner and outer boundaries of the insulating layer, and transmits it to the control module.

[0032] Optionally, when the control module calculates the maximum value of the thickness of the refractory layer, the following formula is satisfied:

[0033]

[0034] Among them, Tr max is the maximum value of the fire-resistant layer thickness, jyc is the insulation layer thickness, nhc is the fire-resistant layer thickness calculation index; σ mix is the density of the refractory mixed material, rks is the thermal diffusion factor of the refractory layer, rdl is the thermal conductivity of the refractory layer, temp max is the maximum temperature that the refractory layer can withstand, brr is the specific heat capacity of the refractory layer, and yl is the pressure resistance factor of the refractory layer.

[0035] Optionally, the control module satisfies the following formula when calculating: yl=(9.81×tr)×h;where I is the total number of mixed materials of the refractory layer, md i is the density of the i-th mixed material, tj i is the volume of the i-th mixed material; tr is the density of the soil, and h is the buried depth of the wire.

[0036] When the control module calculates the maximum value of the fire-resistant layer thickness, refer to the following program code:

[0037]

[0038]

[0039] Specifically, the maximum value of the refractory layer thickness is in meters.

[0040] The unit of insulation thickness is meter.

[0041] The unit of calculation index of refractory layer thickness is meter.

[0042] The unit of density of refractory layer mixture is kilogram per cubic meter. Since the material of refractory layer is mixed, the corresponding mixed density needs to be calculated. The density of refractory layer mixture can reflect the compactness of refractory layer mixture. The higher the density of refractory layer mixture, the stronger its high temperature resistance, which means that it can absorb more heat, but it also needs a thicker layer to effectively delay the spread of heat, so as to provide longer protection. In practical applications, wires are usually not only affected by heat, but also face external pressure. When the density of refractory layer mixture is higher, it often means that the strength of material is greater. This strength is required to be achieved at a thicker layer, so as to ensure that the material does not deform or damage under high temperature and high pressure. Therefore, the increase in thickness is coordinated with the increase in density to cope with possible external pressure and temperature changes.

[0043] The unit of the thermal diffusion factor of the refractory layer is square meters per second. The thermal diffusion factor of the refractory layer indicates the speed at which heat propagates from the high-temperature area to the low-temperature area. The larger the value, the faster the heat propagates. Usually a thicker refractory layer is required to alleviate heat transfer.

[0044] The unit of thermal conductivity of the refractory layer is watt per meter per Kelvin. The thermal conductivity of the refractory layer reflects the ability of the material to conduct heat. The higher the value of the thermal conductivity of the refractory layer, the faster the heat transfer of the corresponding material, so a thicker refractory layer is needed to block the transfer of heat.

[0045] The unit of the maximum temperature that the refractory layer can withstand is K.

[0046] The unit of specific heat capacity of the refractory layer is joule per kilogram per Kelvin. The larger the value of the specific heat capacity of the refractory layer, the higher the ability to delay temperature will be.

[0047] The unit of the pressure resistance factor of the fire-resistant layer is Pascal. This situation mainly takes into account that the environment in which the wires are located is buried in the soil, so the wires will be subject to the pressure of the soil accordingly.

[0048] The density of each mixed material is given in kilograms per cubic meter.

[0049] The volume of each mixed material is in cubic meters.

[0050] The density of soil is measured in kilograms per cubic meter.

[0051] The unit of buried depth of electric wire is meter.

[0052] The above units are only examples, and those skilled in the art may set different units according to actual needs when implementing this solution.

[0053] This embodiment solves the problem that the thickness of traditional electric wires cannot be evaluated. Through the thickness evaluation system, the maximum value of the thickness of the fire-resistant layer is accurately calculated, avoiding the defects of the traditional technology that the thickness of the fire-resistant layer depends on experience or fixed value design.

[0054] Embodiment 2: This embodiment includes all the contents of embodiment 1, and provides a fire-resistant low-voltage wire, combined with Figure 5 shown.

[0055] A fire-resistant low-voltage electric wire, the information storage module is also used to store the ambient temperature and transmit it to the control module;

[0056] The control module obtains the fire resistance time of the fire resistance layer according to the ambient temperature, the maximum temperature of the fire resistance layer, the specific heat capacity of the fire resistance layer, the density of the mixed material of the fire resistance layer and the maximum thickness of the fire resistance layer, and transmits the fire resistance time of the fire resistance layer to the communication module;

[0057] The communication module transmits the fire resistance time of the fire resistance layer to the user end.

[0058] Optionally, when the control module calculates the fire resistance time of the fire resistant layer, the following formula is satisfied: Among them, Tf is the fire resistance time of the refractory layer, temp en The control module calculates the fire resistance time of the fire resistant layer by referring to the following procedures:

[0059]

[0060]

[0061] Specifically, the unit of the fire resistance time of the fire resistant layer is seconds; the unit of the ambient temperature is K, and the ambient temperature can be understood as the maximum predicted temperature when a fire is discovered. By calculating the fire resistance time of the fire resistant layer, the performance attenuation and endurance of the fire resistant layer in a high temperature environment can be described, and then the performance of different fire resistant layer mixed materials can be evaluated.

[0062] Furthermore, according to the calculated fire-resistant time of the fire-resistant layer, the number of layers corresponding to the fire-resistant layer can be calculated according to the following formula: Those skilled in the art may use the "number of layers corresponding to the fire-resistant layer" as a reference value and analyze the actual number of layers of the fire-resistant layer in combination with actual conditions.

[0063] The above units are only examples, and those skilled in the art may set different units according to actual needs when implementing this solution.

[0064] This embodiment solves the problem that the fire resistance time of traditional wires cannot be predicted. By calculating the fire resistance time of the fire-resistant layer, the continuous power supply capacity of the wire in a fire or high temperature environment can be accurately predicted. This function provides a reliable time guarantee for key equipment and systems, making it easier to take emergency measures.

[0065] The contents disclosed above are only preferred feasible embodiments of the present invention, and do not limit the protection scope of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention description and drawings are included in the protection scope of the present invention. In addition, the elements therein can be updated as technology develops.

Claims

1. A fire-resistant low-voltage electric wire, characterized in that: The electric wire comprises a conductor core, an insulating layer, a fire-resistant layer and a sheath layer which are sequentially wrapped from the inside to the outside; The thickness of the refractory layer ranges from 0 to the maximum thickness of the refractory layer, and the maximum thickness of the refractory layer is obtained by evaluating the thickness evaluation system; The thickness assessment system assesses the maximum value of the refractory layer thickness including: obtaining a refractory layer thickness calculation index based on the density of the refractory layer mixed material, the thermal diffusion factor of the refractory layer, the thermal conductivity of the refractory layer, the maximum temperature the refractory layer can withstand, the specific heat capacity of the refractory layer and the pressure resistance factor of the refractory layer; and obtaining the maximum value of the refractory layer thickness based on the refractory layer thickness calculation index and the thickness of the insulating layer.

2. A fire-resistant low-voltage electric wire as claimed in claim 1, characterized in that: The thickness assessment system includes an information storage module, a detection module, a control module and a communication module; The information storage module is used to store the maximum value of the fire-resistant layer's tolerable temperature, the total number of the fire-resistant layer's mixed material components, and the buried depth of the wires, and transmit them to the control module; The detection module is used to detect and obtain the thickness of the insulation layer, the density of the soil, the density of each mixed material, the volume of each mixed material, the specific heat capacity of the refractory layer and the thermal conductivity of the refractory layer, and transmit the results to the control module; The control module obtains the pressure resistance factor of the fire-resistant layer according to the density of the soil and the buried depth of the wire, obtains the density of the fire-resistant layer mixture according to the total number of the fire-resistant layer mixture materials, the density of each mixture material and the volume of each mixture material, obtains the heat diffusion factor of the fire-resistant layer according to the thermal conductivity of the fire-resistant layer, the density of the fire-resistant layer mixture materials and the specific heat capacity of the fire-resistant layer, obtains the fire-resistant layer thickness calculation index according to the density of the fire-resistant layer mixture materials, the heat diffusion factor of the fire-resistant layer, the thermal conductivity of the fire-resistant layer, the maximum value of the fire-resistant layer withstand temperature, the specific heat capacity of the fire-resistant layer and the pressure resistance factor of the fire-resistant layer, obtains the maximum value of the fire-resistant layer thickness according to the fire-resistant layer thickness calculation index and the thickness of the insulating layer, and transmits the maximum value of the fire-resistant layer thickness to the communication module; The communication module transmits the maximum value of the fire-resistant layer thickness to the user end.

3. A fire-resistant low-voltage electric wire as claimed in claim 2, characterized in that: The detection module includes a thickness detection submodule, a density detection submodule, a volume detection submodule, a specific heat capacity detection submodule and a thermal conductivity detection submodule; The thickness detection submodule is used to detect and obtain the thickness of the insulation layer and transmit it to the control module; The density detection submodule is used to detect and obtain the density of the soil and the density of each mixed material, and transmit them to the control module; The volume detection submodule is used to detect and obtain the volume of each mixed material and transmit it to the control module; The specific heat capacity detection submodule is used to detect and obtain the specific heat capacity of the refractory layer and transmit it to the control module; The thermal conductivity detection submodule is used to detect and obtain the thermal conductivity of the refractory layer and transmit it to the control module.

4. A fire-resistant low-voltage electric wire as claimed in claim 3, characterized in that: The thickness detection submodule includes a shooting unit, a preprocessing unit, an edge detection unit and a thickness calculation unit; The shooting unit is used to shoot and obtain an initial image; The preprocessing unit performs denoising on the initial image; The edge detection unit uses an edge detection algorithm to identify the inner and outer boundaries of the insulation layer; The thickness calculation unit obtains the thickness of the insulation layer according to the inner and outer boundaries of the insulation layer, and transmits the thickness to the control module.

5. A fire-resistant low-voltage electric wire as claimed in claim 4, characterized in that: When the control module calculates the maximum value of the refractory layer thickness, the following formula is satisfied: Among them, Tr max is the maximum value of the fire-resistant layer thickness, jyc is the insulation layer thickness, and nhc is the fire-resistant layer thickness calculation index; σ mix is the density of the refractory mixed material, rks is the thermal diffusion factor of the refractory layer, rdl is the thermal conductivity of the refractory layer, temp max is the maximum temperature that the refractory layer can withstand, brr is the specific heat capacity of the refractory layer, and yl is the pressure resistance factor of the refractory layer.

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