A multi-stage backflash discharge arc-extinguishing tube

Abstract

The application discloses a multi-stage backflushing discharge arc-extinguishing tube, which comprises a straight-cylindrical device main body, the inside of the device main body is a hollow structure, the bottom of the device main body is provided with an opening, a plurality of arc-guiding balls are inlaid in the device main body from top to bottom at intervals, backflushing injection nozzles are further arranged on the outer surface of the device main body between two adjacent arc-guiding balls, metal rings and small platforms are installed in the device main body between the two adjacent arc-guiding balls, the small platforms are arranged above the backflushing injection nozzles, the metal rings are installed on the small platforms, and the outer surface of the metal rings is tightly close to the inner side wall surface of the device main body. The application has the advantages of simple structure and reasonable design, the electric arc is backflushed in the one-stage longitudinal backflushing tube and the multi-stage lateral backflushing tube, the electric arc is cut off due to the narrow tube injection effect, the electric arc can form multiple breaking points, the electric arc energy can be greatly reduced, and the electric arc can be cut off and extinguished.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of power fittings for overhead power transmission lines, and relates to a multi-stage backflush discharge arc-extinguishing tube. BACKGROUND

[0002] In China, the distribution of power energy and load centers is very uneven, mainly relying on coal-fired power generation. Coal resources are mostly concentrated in the northwest region, and developable hydro resources are mainly concentrated in the western and central regions, while the load centers of China are concentrated in the eastern coastal areas, Beijing-Tianjin-Tangshan and the developed central region. This determines that China must solve the problem of power supply in the load center by vigorously developing hydro and thermal power generation while building cross-regional, large-capacity and long-distance energy transmission channels.

[0003] With the continuous increase of the voltage level of the transmission line, the state has built a total of "eight cross ten direct" ultra-high voltage projects, forming more than 110 million kilometers of transmission lines, with nearly 50 million base towers. According to statistics, the lightning risk of the power grid is mainly concentrated in the transmission line, and lightning is still an important factor affecting the safety, stability and reliability of the transmission network. The existing lightning protection system is mainly a "blocking type" lightning protection mode, and the main measures are to erect lightning rods and coupling ground wires, reduce the tower grounding resistance, enhance the line insulation and install line arresters, etc. Due to the limitations of effectiveness, safety and economy, it can only protect single weak lightning, and there is a huge gap in the protection of large lightning and multiple lightning. The existing "dredging type" lightning protection mode mainly installs parallel protection gaps at both ends of the insulator string. Although it is simple in structure and convenient to install, it does not have an arc-extinguishing function module, so that short-circuit current continuously flows in the system, and only the circuit breaker can cut off the short-circuit current to "trade off the trip rate for the accident rate", which is easy to cause a large safety accident of the line. At the same time, due to the ablation effect of the short-circuit current, the insulation coordination of the parallel protection gap fails, losing its application function.

[0004] For example, patent No. 2015100691235 discloses a countable arc interruption lightning arrester. Although this patent plays a good role in lightning protection, it still has some deficiencies. Only the longitudinal blowout arc-extinguishing mode is used, and when the arc is strong, the arc is not easy to blow out. SUMMARY

[0005] The present application is directed to the deficiencies of the prior art, and proposes a multi-stage backflush discharge arc-extinguishing tube that can form multiple arc points, greatly reduce arc energy, and is conducive to cutting off and extinguishing the arc.

[0006] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0007] A multi-stage backflush discharge arc-extinguishing tube comprises a straight cylinder-shaped device main body; the device main body is internally hollow; an opening is arranged at the bottom of the device main body, and the opening at the bottom of the device main body forms a bottom backflush tube port; a plurality of arc-guiding balls are inlaid in the device main body at intervals from top to bottom; a backflush airflow jetting tube port is further arranged on the outer surface of the device main body between two adjacent arc-guiding balls, and the backflush airflow jetting tube port is communicated with the internal cavity of the device main body; a metal ring and a small platform are installed in the device main body between two adjacent arc-guiding balls; the small platform is arranged above the backflush jetting port, the backflush airflow jetting port comprises the backflush jetting tube port and the bottom backflush tube port; the metal ring is installed on the small platform, and the outer surface of the metal ring is tightly attached to the inner side wall surface of the device main body.

[0008] As a further technical improvement, the backflush jetting tube port is arranged in an inclined manner, and the backflush jetting tube port has a horn structure. The horn opening faces outward, and the horn-shaped backflush jetting tube port can increase the density difference, temperature difference and pressure difference between the inside and outside of the device main body, so that the backflush jetting effect is more intense, and the arc-extinguishing effect is more obvious.

[0009] As a further technical improvement, the arc-guiding ball has a spherical structure.

[0010] As a further technical improvement, the arc-guiding balls are arranged at equal intervals in the device main body; and the backflush jetting tube port is arranged on the device main body at a position between two arc-guiding balls.

[0011] As a further technical improvement, two adjacent backflush jetting tube ports are arranged on two sides of the device main body, respectively.

[0012] The backflush discharge arc-extinguishing tube in the application is a narrow tube perfusion channel, which is the only channel for the arc to enter the device. Various physical changes occur during the perfusion process.

[0013] 1. Elastic deformation of arc plasma. When the arc plasma enters the backflush tube inlet, the physical shape changes first, from a thick arc to a very thin arc, the radial pressure turns into axial pressure, and due to the narrow tube backflush effect, the ejection speed will accelerate when the arc backflushes.

[0014] 2. Arc temperature rise effect is intensified. After the arc is thinned, the arc cross-sectional area is reduced, and according to the formula , the arc resistance will rise significantly. Since the lightning arc is often used as a constant current source in actual experience work, according to the formula , although the time of the impact is only a few microseconds, the overall energy will be enhanced, and the temperature in the backflush tube will rise.

[0015] Arc radiation, convection, conduction are three ways of energy loss, due to the closed pipeline, that is, the blocking of the external environment, heat cannot be released, which plays a blocking role on the arc, only produces heat and does not dissipate heat, so it will produce a blocking temperature rise, which makes the temperature in the pipe continue to rise.

[0016] 3. The pressure explosion effect is sharply increased. The gradual increase of temperature causes the accumulation of arc to further intensify the pressure explosion effect, so that the arc jetting force is greater.

[0017] The device body is made of high-strength, high-temperature-resistant and high-pressure-resistant alloy ceramic, rare earth ceramic, graphene-ceramic composite material, organic ceramic, synthetic silicone rubber, organic insulating material, alloy glass, rare earth glass, graphene glass and organic glass; the arc guide ball is made of conductive material;

[0018] The arc guide ball at the bottom end and the lower cavity of the device body form a first longitudinal recoil pipe, which is a semi-closed space; the device body segment between two adjacent arc guide balls forms a side recoil pipe, and since multiple arc guide balls are arranged in the device body, multiple side recoil pipes are formed in the device body, which are semi-closed spaces;

[0019] The diameter of the first longitudinal recoil pipe is smaller than the diameter of the arc. When the arc enters the first longitudinal recoil pipe from the bottom, the arc goes further in due to the limitation of the recoil pipe wall. When the arc enters the first longitudinal recoil pipe, the density, speed and temperature increase step by step, which leads to a step-by-step increase in the pressure in the pipe, and finally produces a pressure explosion effect, so that the arc at the bottom of the blocked recoil pipe is subjected to a reverse elastic force, and the direction of most of the arc is changed by 180°. A small part of the arc enters the side recoil pipe due to the coulomb force, and the arc energy is weakened again. The rebounded arc has greater speed, density and pressure, forms a cavity effect at the entrance and acts on the outer arc, causing the arc at the port to be cut off; due to the semi-closed nature of the first longitudinal recoil pipe, the temperature in the pipe rises instantaneously, forming a density difference and a temperature difference between the inside and the outside. A small amount of air in the first longitudinal recoil pipe expands to form a reverse jet flow and acts on the arc, forming a cavity effect of the longitudinal blowing gas flow at the center of the arc axis to weaken the arc energy. The greater the arc energy entering the recoil pipe, the greater the effect of the narrow tube perfusion of the recoil pipe, the greater the density difference and temperature difference, and even the arc is extinguished;

[0020] And because of the multi-stage arc guide ball conductivity, the electric arc will be into the multi-stage side recoil tube, repeated multi-stage recoil effect, the side of the recoil effect on the arc, achieve horizontal multi-stage truncation; The greater the arc energy, the greater the density difference and temperature difference, the stronger the recoil ability; The arc in the first stage of the longitudinal recoil tube is weakened by the recoil effect, so that the energy of the arc entering the multi-stage side recoil tube is reduced, and the arc is extinguished due to the transverse truncation of the multi-stage side recoil tube.

[0021] The metal ring is attached to the inner wall of the device body, and its position is fixed by a small platform to avoid displacement during the recoil process. The metal conductivity of the metal ring ensures that the arc can smoothly enter the device body to achieve the above-mentioned recoil function. At the same time, due to the large force at the outlet of the device body, the metal ring can also protect the outlet of the device body. Designing a metal ring in the side recoil tube can ensure that the arc achieves the recoil effect in the specified recoil tube channel.

[0022] The principle structure of the present patent is different from the structure and principle of the existing technology "angular lightning arrester (patent application number CN200810178607.3)" in the following aspects:

[0023] 1) There is no time lag effect in arc extinction. The angular lightning arrester sprays arc jet through lightning flashover, which requires the conductivity of the metal components or ion components of the plasma gas produced by melting, vaporization, etc. These components are in a floating state in the air, reducing the insulation ability of the air and easily causing arc displacement, and spraying arc jet at the arc displacement point to block the arc. Obviously, in the process of arc flashover - melting, vaporization of conductive materials - spraying arc jet, there is a time lag effect, that is, the energy of the angular lightning arrester spraying arc jet is less than the energy of the lightning flashover arc. The narrow tube filling effect proposed in the present patent fully utilizes the elastic deformation of arc plasma, and when the arc plasma enters the recoil tube inlet, the physical shape changes from thick arc to extremely thin arc, and the radial pressure becomes axial pressure. Due to the narrow tube recoil effect, the spraying speed increases during arc recoil.

[0024] 2) High arc extinction threshold. The arc extinguishing cylinder and gas generating device of the angular lightning arrester are made of polyamide resin (also known as nylon), which can withstand a temperature of about 500°C, which is much lower than the arc burning temperature (up to 3726.85°C). Therefore, the arc extinguishing cylinder and gas generating device are easily affected by high temperature, which eventually leads to burst. The present patent proposes the use of high-strength, high-temperature-resistant, and high-pressure-resistant non-conductive materials, such as alloy ceramics, rare earth ceramics, graphene-ceramic composites, organic ceramics, synthetic silicone rubber, organic insulating materials, alloy glass, rare earth glass, graphene glass, and organic glass, combined with new materials

[0025] 3) There is no high-temperature baking gas production mode. Since the corner lightning arrester is used to blow off the arc by spraying arc jet, and blow off the arc in the gap. Among them, the spraying arc jet needs high-temperature baking gas production, which seriously causes the loss of gas production materials and significantly reduces the service life of the device. The patent proposes a plasma narrow tube perfusion effect: the radial displacement of the arc into the recoil tube becomes axial expansion by using the flowability of arc plasma; the pressure, temperature and density superposition effects of the incoming arc and the outgoing arc make the pressure in the recoil module multiply rapidly, destroy the subsequent energy of the arc, and block the continuity of the arc. Therefore, there is no high-temperature baking gas production mode, which ensures the loss of the patent material and long service life.

[0026] Compared with the prior art, the present application has the following advantages:

[0027] 1. The present application can form multiple arc breaking points by recoiling and cutting the arc in the primary longitudinal recoil tube and the multi-stage lateral recoil tube, which can greatly reduce the arc energy and is beneficial to cutting and extinguishing the arc.

[0028] 2. The present application can better produce density difference, temperature difference and pressure difference through the horn-shaped recoil jet pipe opening, and the recoil effect is more intense.

[0029] 3. The device body in the present application uses lightning energy for arc extinguishing, and does not depend on the size of the power frequency energy.

[0030] 4. The present application uses current heat effect to change the temperature difference inside and outside the device body, so as to produce air pressure difference to blow out the arc, avoid using external gas production materials, and is beneficial to long-term repeated use. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The structure diagram of example 1 in the present application.

[0032] Figure 2 The structure diagram of example 2 in the present application.

[0033] The figure legend: 1-device body, 2-arc guide ball, 3-recoil jet pipe opening, 4-metal ring, 5-small platform. DETAILED DESCRIPTION

[0034] The present application will be further described below in conjunction with the drawings.

[0035] Example 1:

[0036] A multi-stage backflush discharge arc extinguishing tube comprises a straight cylinder-shaped device main body 1; the inside of the device main body 1 is hollow; an opening is arranged at the bottom of the device main body 1, and the opening at the bottom of the device main body constitutes a bottom backflush tube port; a plurality of arc guiding balls 2 are inlaid in the device main body 1 from top to bottom at intervals; a backflush jet tube port 3 is further arranged on the outer surface of the device main body between two adjacent arc guiding balls, and the backflush jet tube port 3 is communicated with the internal cavity of the device main body 1; a metal ring 4 and a small platform 5 are installed in the device main body between two adjacent arc guiding balls; the small platform 5 is arranged above the backflush jet port, and the backflush jet port comprises the backflush jet tube port 3 and the bottom backflush tube port; the metal ring 4 is installed on the small platform 5, and the outer surface of the metal ring 4 is tightly attached to the inner side wall of the device main body 1.

[0037] The backflush jet tube port 3 is arranged obliquely; the arc guiding ball 2 is a spherical structure; the arc guiding balls 2 are arranged at equal intervals in the device main body 1; and the backflush jet tube port 3 is arranged on the device main body 1 at the intermediate position between two arc guiding balls 2. Two adjacent backflush jet tube ports are arranged on the two sides of the device main body respectively.

[0038] The working principle of the embodiment is as follows:

[0039] The device body 1 is made of ceramic material with high strength, high temperature resistance and high pressure resistance; the arc guiding ball 2 is made of conductive material; the arc guiding ball 2 at the bottom end and the lower part cavity of the device body 1 form a first longitudinal recoil tube, which is a semi-closed space; two adjacent arc guiding balls 2 form a side recoil tube in the device body 1, and since the device body 1 is provided with a plurality of arc guiding balls 2, a plurality of side recoil tubes are formed in the device body 1, which are semi-closed spaces; the diameter of the first longitudinal recoil tube is smaller than the diameter of the arc, when the arc enters the first longitudinal recoil tube from the bottom, the farther the arc goes, the greater the arc is affected by the narrow tube perfusion effect of the recoil tube due to the limitation of the recoil tube wall, and the density, speed and temperature of the arc entering the beginning of the recoil tube increase step by step, which leads to the step-by-step increase of the pressure in the tube, and finally the pressure explosion effect is generated, so that the arc is subjected to the reverse elastic force at the bottom of the blocked recoil tube, and the direction of the arc changes by 180°. The rebounded arc has greater speed, density and pressure, forms a cavity effect at the entrance and acts on the outer arc, resulting in the cutting off of the arc at the port; at this time, the arc density in the first longitudinal recoil tube increases, and due to the semi-closed characteristic of the first longitudinal recoil tube, the temperature in the tube rises instantaneously, forming a density difference and a temperature difference between the inside and the outside; the greater the energy of the arc entering the recoil tube, the greater the narrow tube perfusion effect of the recoil tube, and the greater the density difference and temperature difference formed, and even the arc is extinguished; and due to the conductivity of the multi-stage arc guiding ball 2, the arc will enter the multi-stage side recoil tube by inertia, the arc is subjected to the elastic force, the direction of the arc movement changes, the multi-stage recoil effect is repeated, the side recoil acts on the arc, and the horizontal multi-stage cutting is realized; the greater the arc energy, the greater the density difference and temperature difference formed, so that the recoil ability is stronger; the arc in the first longitudinal recoil tube is subjected to the cavity effect, which weakens the energy of the arc, reduces the energy of the arc entering the multi-stage side recoil tube, and due to the horizontal cutting effect of the multi-stage side recoil tube, the arc forms multiple breakpoints, which accelerates the extinction of the arc; the metal ring 4 is attached to the inner wall of the device body 1, and its position is fixed by the small platform 5 to avoid displacement during the recoil process; the metal conductivity of the metal ring 4 ensures that the arc can smoothly enter the device body 1, realizing the above-mentioned recoil function; at the same time, due to the large stress at the outlet of the device body 1, the metal ring 4 can also protect the outlet of the device body 1; the design of the metal ring 4 in the side recoil tube can ensure that the arc realizes the recoil effect in the specified recoil tube channel.

[0040] Example 2

[0041] The difference between this embodiment and example 1 is that the recoil injection pipe port 3 is in a horn structure.

[0042] The horn opening faces outward, and the horn-shaped recoil injection pipe port 3 can increase the density difference, temperature difference and pressure difference between the inside and outside of the device body 1, making the recoil injection effect more intense and the arc extinguishing effect more obvious.

[0043] It will be apparent to those skilled in the art that numerous and various modifications can be made without departing from the application. Such modifications are not to be regarded as a departure from the scope of the application, and all such modifications as can be suggested by the disclosure along with their equivalents are intended to be included within the scope of the application.

Claims

1. A multistage backflash discharge arc-extinguishing tube comprising a straight cylindrical device body (1); characterized in that: The device body (1) is hollow; the bottom of the device body (1) is provided with an opening; a plurality of arc guiding balls (2) are embedded in the device body (1) from top to bottom at intervals; The outer surface of the device body between two adjacent arc guiding balls is further provided with a backflushing jet nozzle (3); A metal ring (4) and a small platform (5) are installed in the device body between two adjacent arc guiding balls; the small platform (5) is arranged above the backflushing jet nozzle; the metal ring (4) is installed on the small platform (5), and the outer surface of the metal ring (4) is tightly attached to the inner side wall of the device body (1); The arc guiding balls (2) are arranged at equal intervals in the device body (1); and the backflushing jet nozzle (3) is arranged on the device body (1) at the position between two arc guiding balls (2); Two adjacent backflushing jet nozzles are arranged on the two sides of the device body.

2. The multistage backflash arc-extinguishing tube according to claim 1, characterized in that: The backflushing jet nozzle (3) is arranged obliquely, and the backflushing jet nozzle (3) has a horn-shaped structure.

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