A high-voltage cable joint flame-out and explosion relief device and a working method thereof

Abstract

The application discloses a high-voltage cable joint flame extinguishing and explosion venting device based on a double-stage energy releasing module and relates to the technical field of power equipment safety protection. The device comprises a composite structure protection shell, a double-stage energy releasing module arranged on the composite structure protection shell, and a first-stage energy releasing unit and a second-stage energy releasing unit arranged in series along the airflow direction. The first-stage energy releasing unit comprises a plurality of guide vanes for guiding the disordered jet flow into directional airflow, and the plurality of guide vanes are fixed louver structures. The second-stage energy releasing unit comprises a continuous closed channel for extinguishing the flame and attenuating the airflow pressure, and the continuous closed channel is a turning labyrinth structure.

Description

Technical Field

[0001] This invention belongs to the field of power equipment safety protection technology, and specifically refers to a high-voltage cable joint flame extinguishing and explosion relief device based on a two-stage energy discharge module. Background Technology

[0002] High-voltage cable joints, as critical connection points in power transmission networks, directly impact grid security through their operational reliability. Due to factors such as composite insulation involving different material interfaces, concentrated electric fields, and deviations in on-site installation processes, joints become one of the most vulnerable links in cable systems. During long-term operation, joints may experience short-circuit arcing faults due to insulation aging, partial discharge, external force damage, or internal defects. Studies show that such arcs can release enormous energy within milliseconds, generating temperatures exceeding 10,000°C, rapidly vaporizing nearby insulating materials (such as silicone rubber and epoxy resin) and metal conductors. This causes a sharp rise in internal pressure and temperature, ultimately evolving into a violent gas explosion, accompanied by jet flames, molten metal droplets, and toxic fumes. This phenomenon, known as "arc flash explosion," is a major cause of electrical fires, severe equipment damage, and even personal injury.

[0003] To address this threat, various protective solutions have been developed in this field. Early solutions primarily focused on improving reliability through enhanced insulation and mechanical design of the connector body, representing a "prevention-oriented" strategy. However, for occasional failures that cannot be completely eliminated, "post-accident protection" devices are necessary. Common protective measures include installing rigid explosion-proof protective boxes on cable connectors or wrapping them with explosion-proof insulation blankets in densely populated equipment areas. Among these, the most widely used and simplest solution is to create a traditional circular pressure relief hole in the protective housing. The design logic of this solution is that in the event of an internal explosion, high-pressure gas can be rapidly released through the pressure relief hole, preventing the housing from physically cracking due to pressure buildup, thereby preventing greater structural damage.

[0004] However, existing technical solutions represented by circular pressure relief holes have a series of inherent and insurmountable safety defects: traditional protective measures involve opening simple circular or strip-shaped pressure relief holes on the connector protective shell. The pressure relief holes only serve as pressure release channels. High-temperature flames and explosion products are ejected at high speed together, and the device itself becomes a huge jet fire source, directly transferring the internal fire risk to the external environment. This results in an inherent defect that the release process is disordered and uncontrollable, and the fire cannot be stopped. Summary of the Invention

[0005] To address the technical problems of existing devices being unable to control the venting process and prevent fires, this invention provides a high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy venting module. The technical solution is as follows:

[0006] On one hand, a high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy venting module is provided, characterized in that: the flame extinguishing and explosion venting device includes: a protective shell; a two-stage energy venting module disposed on the protective shell, the two-stage energy venting module being sealed to the composite structure protective shell; the two-stage energy venting module includes: a primary energy venting unit and a secondary energy venting unit arranged in series; the primary energy venting unit has multiple guide vanes arranged along a preset tilt angle to guide the disordered jet into a directional airflow. The secondary energy venting unit forms a labyrinthine continuous sealed channel with multiple turning structures to extinguish the flame and attenuate the airflow pressure.

[0007] Optionally, the protective shell is a composite structure protective shell, including an upper shell, a lower shell, and a wall. The upper shell and the lower shell are connected by flange edges and connecting bolts. The wall includes an inner lining layer, a structural layer, and an outer layer. The inner lining layer includes an arc-resistant material, the structural layer includes a pressure-bearing material, and the outer layer includes a flame-retardant material.

[0008] Optionally, the angle between the plurality of guide vanes and the main axis of the airflow is in the range of 30° to 40°; and the thickness of the plurality of guide vanes is between 1 and 3 mm.

[0009] Optionally, the continuous sealed channel includes interconnected gradually expanding transition channels and labyrinth channels, wherein the gradually expanding transition channels are positioned corresponding to the positions of the plurality of guide vanes; the cross-section of the labyrinth channel is rectangular and includes at least 3 channel bends, wherein the bend angle of the channel bends is 90° or 180°.

[0010] Optionally, the roughness of the inner wall of the maze passage is Ra>6.3μm.

[0011] Optionally, the continuous sealed channel further includes a detachable filter plate mounting slot, which is located at the exit of the labyrinth channel and is used to insert a filter plate to filter submicron-level dust; the pore size of the filter plate is between 80 and 300 micrometers.

[0012] Optionally, the primary energy venting unit and the secondary energy venting unit are connected to each other via a connecting flange, a standard interface flange, and bolts, and a metal spiral wound gasket is also provided at the connection between the primary energy venting unit and the secondary energy venting unit.

[0013] Optionally, the flame extinguishing and explosion relief device includes at least two dual-stage energy relief modules disposed on the same side of the protective shell.

[0014] Optionally, the dual-stage energy dissipation module is manufactured by 3D printing, or the dual-stage energy dissipation module is manufactured by precision casting.

[0015] On the other hand, a working method is provided for the high-voltage cable joint flame extinguishing and explosion venting device based on the two-stage energy venting module: the multiple guide vanes in the first-stage energy venting unit direct the high-temperature and high-pressure mixed gas generated by the explosion inside the wall to a specific direction and perform preliminary cooling and filtration; the continuous sealed channel in the second-stage energy venting unit completely extinguishes the treated high-temperature and high-pressure mixed gas and further attenuates the pressure and filters particulate matter; the flame extinguishing and explosion venting device safely discharges the treated gas.

[0016] The beneficial effects of the technical solution provided by the embodiments of the present invention include at least the following: providing a systematic safety protection solution that can achieve directional control, active flame extinguishing, and efficient purification of internal explosions in cable joints, fundamentally improving the level of intrinsic safety, greatly expanding the applicable scenarios of the device, and ensuring a high degree of controllability and predictability of the explosion venting process. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention.

[0019] Figure 2 This is a schematic diagram of the composite protective shell of the device of the present invention in its disassembled state.

[0020] Figure 3 This is a schematic diagram of the two-stage energy dissipation module.

[0021] Figure 4 This is a magnified view of a primary energy dissipation unit.

[0022] Figure 5 This is a magnified view of a secondary energy dissipation unit.

[0023] 1-Composite structure protective shell, 101-Upper shell, 102-Lower shell, 103-Flange edge, 104-Connecting bolt, 105-Inner liner, 106-Structural layer, 107-Outer layer, 108-Standard interface flange, 109-Bolt; 2-Dual-stage energy dissipation module, 201-Module shell, 202-Connecting flange, 203-Metal spiral wound gasket, 204-First-stage energy dissipation unit, 2041-Multiple guide vanes, 2042-First-stage airflow channel; 205-Second-stage energy dissipation unit, 2051-Maze channel, 2052-Channel bend, 2053-Roughened inner wall surface, 2054-Removable filter plate mounting slot, 2055-Gradually expanding transition channel. Detailed Implementation

[0024] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0025] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0026] In the embodiments of this invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning. Similarly, the terms "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning.

[0027] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0028] The present invention aims to overcome the inherent defects of traditional pressure relief holes described in the background art, such as disordered release, inability to extinguish flames, and direct emission of harmful products, and to provide a systematic safety protection solution that can achieve directional control, active flame extinguishing, and efficient purification of internal explosions in cable joints.

[0029] This invention proposes a flame extinguishing and explosion venting device for high-voltage cable joints based on a two-stage energy venting module. The device includes: a composite structure protective shell 1; and a two-stage energy venting module 2 disposed on the composite structure protective shell 1, the two-stage energy venting module 2 being sealed to the composite structure protective shell 1. The two-stage energy venting module 2 includes: a primary energy venting unit 204 and a secondary energy venting unit 205 arranged in series along the airflow direction. The primary energy venting unit 204 includes multiple guide vanes 2041 for guiding the disordered jet into a directional airflow, the multiple guide vanes 2041 being a fixed louver structure. The secondary energy venting unit 205 includes a continuous sealed channel for extinguishing the flame and attenuating the airflow pressure, the continuous sealed channel being a labyrinthine structure. This invention aims to overcome the inherent defects of traditional pressure relief holes in the prior art, such as disordered release, inability to extinguish flames, and direct emission of harmful products, and provides a systematic safety protection solution capable of directional control, active flame extinguishing, and efficient purification of internal explosions in cable joints. The core concept of the technical solution adopted by this invention to solve its technical problem lies in the following: constructing a protective shell with a multi-layered composite structure and an integrated energy dissipation module that integrates two levels of functions in synergy. The first-level energy dissipation unit integrates the disordered jet into a directional airflow through the guide vanes, effectively controlling the vector direction of energy release. The second-level energy dissipation unit utilizes its ultra-long flow channel and rough cold wall surface to completely interrupt the combustion chain reaction through the continuous "wall quenching" effect, ensuring that the flame is completely extinguished inside the device.

[0030] Optionally, the primary energy release unit 204 and the secondary energy release unit 205 are integrated into a single functional module in series in physical space. This is the physical basis for realizing "process management". Without this series architecture, it is impossible to integrate the two processes of "rapid pressure relief and diversion" and "deep quenching and filtration" that are closely linked in terms of timing and function into a compact space, thus making it impossible to systematically solve the three major problems of flame, pressure and particulate matter.

[0031] When an electric arc explosion occurs inside the cable joint, the composite protective shell 1 acts as the first line of defense, withstanding the initial pressure and containing the explosion products. Subsequently, the explosion energy and products are introduced into the two-stage energy release module 2, where they undergo two active treatment stages: the first-stage directional venting and coarse filtration by the primary energy release unit 204, and the second-stage deep flame extinguishing and fine filtration by the secondary energy release unit 205. Ultimately, the dangerous explosion output is transformed into safe and clean gas emissions. This series design of "enclosure within the shell, treatment within the module" achieves a fundamental shift from "open-hole pressure relief" to "process management."

[0032] The composite protective shell 1 includes an upper shell 101, a lower shell 102, and a wall. The upper shell 101 and the lower shell 102 are connected by a flange 103 and connecting bolts 104.Figure 1 and Figure 2 As shown, the composite protective shell 1 constitutes the main cavity of the device. It adopts a split design, with the upper shell 101 and lower shell 102 aligned via peripheral flanges 103 and fastened together using multiple sets of connecting bolts 104. This design facilitates the rapid installation and encapsulation of existing cable connectors on-site.

[0033] The wall includes an inner lining layer 105, a structural layer 106, and an outer layer 107; the inner lining layer 105 includes an arc-resistant material, the structural layer 106 includes a pressure-bearing material, and the outer layer 107 includes a flame-retardant material.

[0034] The composite protective shell 1 is the main body of the device. Its function is not only to accommodate the cable joint, but also to provide critical time buffer and spatial constraint in the initial stage of an explosion. It adopts a unique triple-protection composite structure, in which the inner lining layer 105 is an arc-resistant layer, which is composed of ceramicized silicone rubber or microporous alumina ceramic sheets. Its core mechanism is to directly resist the thermal erosion of the arc plasma by utilizing the extremely high thermal stability and insulation properties of the material (ceramized silicone rubber can be transformed into a stable ceramic hard shell at >1500℃ under an electric arc), preventing the metal shell from being melted through and forming a secondary breakdown point, and ensuring that the fault is strictly confined within the shell. This layer is closely attached to the inner surface of the cavity and is preferably made of ceramicized silicone rubber material. Its main function is to directly resist the high-temperature ablation of the fault arc. At the temperature of thousands of degrees Celsius generated by the arc, the material will sinter and transform into a hard ceramic state, effectively preventing the metal layer of the shell from being melted through and maintaining the sealing integrity of the cavity.

[0035] Among them, structural layer 106 is the pressure-bearing layer and the main load-bearing structure. It can be made of high-strength aluminum alloy (such as 6061-T6) through precision casting or spinning, preferably 304 stainless steel or high-strength aluminum alloy through rolling welding or casting processes. Its core function is: as a mechanical skeleton, its thickness and reinforcing rib layout are determined according to explosion mechanics simulation to absorb and disperse the impact load generated by the explosion (usually designed to withstand instantaneous pressure ≥2.0MPa), ensuring that the shell does not experience brittle fracture or permanent bulging, providing a structural basis for the orderly release of internal pressure, and is the key to ensuring that the entire device does not suffer structural damage under extreme conditions.

[0036] The outer layer 107 is a flame-retardant and heat-insulating layer, composed of intumescent fire-retardant coating or fiberglass-reinforced composite flame-retardant sheath. Its core mechanism is the utilization of the material's thermal barrier properties. The fire-retardant coating expands tens of times when heated, forming a low-thermal-conductivity foamed carbon layer, effectively blocking internal heat radiation outward (reducing the outer surface temperature below the cable sheath's ignition point, such as <150℃), preventing "heat spread" and ignition of adjacent equipment. This layer covers the outer surface of the structural layer, preferably using intumescent fire-retardant coating or flame-retardant composite material. Its function is bidirectional: on the one hand, it isolates internal fault heat from the external environment, preventing secondary fires; on the other hand, when an external ignition source is present, this layer forms a heat-insulating barrier, protecting the internal equipment. To achieve this function, two main material systems are employed. The first is intumescent fire-retardant coatings. These coatings undergo complex chemical reactions when heated, expanding in volume to form a dense, porous carbon layer with excellent thermal barrier properties. For example, epoxy resin-based intumescent coatings have strong adhesion, good mechanical properties, and resistance to chemical corrosion. Through modification, they can achieve weather resistance suitable for outdoor use. A typical intumescent system uses modified epoxy resin as the film-forming agent, combined with ammonium polyphosphate as the acid source, pentaerythritol as the carbon source, and melamine as the gas source. The second is fiberglass-reinforced composite flame-retardant sleeves. These materials provide protection through physical barriers and fiber reinforcement, typically in the form of flexible or semi-rigid sleeves. For example, ceramicized silicone rubber composite sleeves, in addition to being flame-retardant, have the characteristic of sintering in flames to form a hard ceramic protective shell, providing a higher level of fire resistance and protection against mechanical damage. Examples include fiberglass cloth reinforcement with a matrix of silicone rubber containing ceramic fillers (such as mica and wollastonite).

[0037] like Figure 3 As shown, the two-stage energy dissipation module 2, as the core functional component of this invention, is connected to the standard interface flange 108 via its connecting flange 202. A metal spiral wound gasket 203 is provided between the two to ensure the reliability of the static seal, and they are fastened with bolts 109.

[0038] like Figure 3 and Figure 4As shown in the enlarged view, the primary energy dissipation unit 204 is located at the module inlet end, directly receiving the explosive impact from the protective shell. The primary energy dissipation unit 204 includes a series of parallel guide vanes 2041 at a fixed angle of 30°-45° to the module axis, integrally formed with the module shell. The thickness of the guide vanes 2041 is 1-3mm, and the spacing between the vanes is determined based on the pressure relief area. It can forcefully guide the flow, utilizing the momentum exchange principle of solid walls. When a chaotic high-speed jet enters, the guide vanes 2041 cut, integrate, and change its direction of motion, forming one or more concentrated jets with controllable direction, laying the foundation for subsequent processing. When a disordered jet impacts the guide vanes 2041, its normal momentum is absorbed, and its tangential momentum is guided, thereby integrating all the outflow into a single direction (e.g., vertically upward) consistent with the inclination angle of the guide vanes 2041. This achieves the artificial setting and controllability of the explosive energy release direction, solving the 360° jetting problem.

[0039] Without the design of multiple guide vanes 2041, the explosive jet would remain in a state of disordered diffusion. These multiple guide vanes 2041 transform the spherical shock wave into a directional concentrated jet through forced momentum exchange. This is the only and necessary structural means to achieve "directional discharge" and avoid dangerous 360° jetting, while also creating stable inflow conditions for subsequent secondary treatment.

[0040] The primary airflow channel 2042 is formed by a narrow gap between the plurality of guide vanes 2041. High-speed airflow generates strong turbulence as it passes through, achieving rapid heat exchange with the metal guide vanes and providing initial cooling. Simultaneously, through inertial effects, larger molten metal droplets and carbon black particles from the explosion products collide with and are captured by the guide vane walls, achieving coarse filtration.

[0041] The narrow channel of the primary energy dissipation unit 204 causes a sharp increase in airflow velocity and Reynolds number, creating intense turbulence and greatly enhancing heat exchange between the gas, solid, and wall surfaces, thus achieving initial cooling. Simultaneously, based on the Stokes number (Stk) principle, larger molten metal droplets (Stk>>1) cannot follow the airflow direction due to inertia, violently impacting the guide vane surface and being captured, removing >80% of particles larger than 100 micrometers.

[0042] like Figure 3 and Figure 5 As shown in the enlarged view, the secondary energy venting unit 205 provided by this invention smoothly connects to the primary energy venting unit via a gradually expanding transition channel 2055, aiming to further optimize the flow field and reduce pressure loss. The secondary energy venting unit 205 consists of a continuous sealed channel, including a labyrinth channel 2051 and the gradually expanding transition channel 2055, which together form... Figure 5The illustrated labyrinthine structure includes at least three consecutive acute-angle (e.g., 90°) or U-shaped (180°) turning channels 2052 connected in series. Each acute-angle or right-angle turn is a key node for pressure wave attenuation, where the explosion shock wave is reflected, interfered with, and dissipated, its intensity being weakened step by step. The channel cross-section can be circular or rectangular. When the channel cross-section is circular, the total flow channel length is designed to be 15-30 times the inlet diameter. The ultra-long tortuous path aims to maximize the extension of airflow residence time, creating conditions for deep processing. The secondary energy dissipation unit 205 can achieve multi-stage attenuation of the pressure wave based on the principle of acoustic impedance mismatch and eddy current dissipation. At each abrupt change in the channel cross-section and direction turning point, the explosion pressure wave undergoes partial reflection and interference, and the acoustic energy is converted into eddy current heat energy. At the same time, the wall friction continuously consumes its mechanical energy, causing the pressure wave intensity to decrease exponentially. Furthermore, the roughened inner wall surface 2053 included in the secondary energy dissipation unit 205 can achieve wall quenching of the flame, which is crucial for achieving "flame extinguishing." The inner wall of the channel undergoes special treatment (coated with a high thermal conductivity coating) to significantly increase its surface area and roughness. Based on the quenching distance theory, when the flame front enters a narrow channel (its size is close to or smaller than the quenching distance of the mixture), free radicals frequently collide with the cold wall surface and become deactivated, forcibly terminating the combustion chain reaction. The labyrinthine channel 2051, through multiple continuous turns, repeatedly applies the quenching effect, ensuring that even flames not completely extinguished in the first stage are 100% extinguished. The roughening treatment of the inner wall (Ra>6.3μm) and the coating with a high thermal conductivity ceramic coating further increase the effective contact area and improve quenching efficiency. Simultaneously, the rough surface also facilitates the adsorption of finer particles.

[0043] This is the core of achieving the inherent safety goal of "flame extinguishing." The ultra-long cold wall contact path formed by multi-stage transitions is the decisive structure for completely extinguishing the flame using the "wall quenching" principle. The roughened inner wall surface of 2053 greatly enhances the quenching efficiency and particulate matter adsorption capacity. Without this design, the flame would inevitably be ejected along with the airflow.

[0044] Optionally, the continuous sealed channel further includes a detachable filter plate mounting slot 2054, which is located at the outlet of the labyrinth channel 2051. The detachable filter plate mounting slot 2054 is a sliding groove structure, allowing the insertion of a filter plate (such as a porous ceramic plate or a sintered metal filter element) via a sliding connection to achieve filtration of submicron-level dust, enabling diffusion sedimentation and adsorption filtration of fine particles. For submicron-level particles (such as dust) lacking inertial force, they migrate to the wall surface and are adsorbed mainly through Brownian diffusion and turbulent diffusion in the long flow channel. The module can also be equipped with a detachable porous ceramic filter plate slot, utilizing its micropores (e.g., 10-50 μm) for surface filtration and deep interception, achieving ultimate purification of aerosols and ultrafine particles, with a filtration efficiency of over 95%.

[0045] Optionally, the dual-stage energy dissipation module 2 is integrally formed using precision casting or metal 3D printing technology to ensure that there are no connecting gaps in the complex internal flow channels, and has extremely high structural strength and sealing performance.

[0046] Optionally, the flame extinguishing and explosion venting device includes at least three two-stage energy venting modules 2.

[0047] On the other hand, the present invention provides the working process of a flame extinguishing and explosion relief device for when an arc fault occurs inside a cable joint, the insulation material rapidly decomposes and generates gas, causing a sudden rise in pressure and temperature inside the composite protective shell 1 within milliseconds, including:

[0048] First, the multiple guide vanes 2041 in the primary energy dissipation unit 204 direct the high-temperature and high-pressure mixed gas generated by the explosion inside the wall and perform preliminary cooling and filtration; at this time, disordered energy is converted into a directional jet, and most of the initial explosion energy and coarse particles are released and stripped away in this stage.

[0049] When the pressure exceeds the cavity's withstand threshold, the high-temperature, high-pressure mixture breaks through the channel and enters the primary energy release unit 204. Forced guided by multiple guide vanes 2041, the disordered energy is converted into a directional jet, and most of the initial explosion energy and coarse particles are released and stripped away during this stage.

[0050] Secondly, the continuous sealed channel in the secondary energy release unit 205 completely extinguishes the treated high-temperature and high-pressure mixed gas and further reduces pressure and filters particulate matter.

[0051] The airflow enters the secondary energy dissipation unit 205 through the gradually expanding transition channel 2055. In the labyrinth channel 2051, the residual pressure wave is drastically attenuated at multiple turning points 2052; at the same time, the flame is completely quenched on the roughened inner wall surface 2053; and the remaining harmful particles are further filtered.

[0052] Finally, after undergoing the above two-stage coordinated treatment, the substance emitted from the module outlet by the flame extinguishing and explosion relief device has been transformed into a low-temperature (significantly lower than the ignition point of the surrounding materials), low-speed, flameless, and clean gas, thus achieving a fundamental transformation from "explosive release" to "safe emission".

[0053] The device is installed directly on the outside of the cable joint. Its core design is to provide basic protection and sealing through the composite structure protective shell 1, and to carry out intelligent and graded safety treatment of internal explosions through the two-stage energy dissipation module 2, so as to achieve harmless emission.

[0054] The key technical point of this invention lies in constructing a "two-level collaborative, functionally integrated" active safety management system to replace the traditional single pressure relief hole. Its core is not a simple improvement of a single component, but a completely new design philosophy and system architecture. Compared with existing technologies, the flame extinguishing and explosion relief device and method provided by this invention, through its innovative combination of "composite protection" and "process management," has achieved significant and multifaceted technical progress and beneficial effects, specifically reflected in the following three core aspects: First, it achieves a fundamental improvement in intrinsic safety. Traditional circular pressure relief holes only passively release pressure; they are merely simple geometric openings, their function limited to releasing pressure. When an internal electric arc ignites combustible gas and forms a flame, the flame is ejected at high speed along with the high-pressure airflow without obstruction. The pressure relief hole essentially becomes a "flame jet," directly transforming the internal fire risk into an attack on the external flame, completely failing to isolate or extinguish the flame. Essentially, it transfers the internal explosion risk to the external environment without any treatment—a "risk transfer" strategy. In stark contrast, this invention combines the forced physical guidance of a "fixed louver structure" with the active chemical quenching of a "labyrinth structure," transforming the explosion venting process into an internal "hazard elimination" process. Specifically, the primary energy venting unit integrates the disordered jet into a directional airflow through guide vanes, effectively controlling the vector direction of energy release; the secondary energy venting unit utilizes its ultra-long flow channel and rough, cold wall surface to completely interrupt the combustion chain reaction through a continuous "wall quenching" effect, ensuring the flame is completely extinguished inside the device. Furthermore, the hazards of traditional explosions are not limited to pressure and flames; they also include high-temperature molten metal droplets (such as copper and aluminum), carbon black particles formed from the pyrolysis of insulating materials, and various toxic gases. Circular pressure relief holes offer no constraint, guidance, or filtration capability for these harmful products. These high-temperature, high-energy solid and liquid particles are sprayed in a scattering pattern in all directions, with their diffusion range and direction being completely random and unpredictable, easily causing severe secondary erosion and contamination of nearby electrical equipment and cables, and even triggering cascading failures. The two-stage structure of this application efficiently intercepts over 95% of molten metal particles and carbon black through mechanisms such as inertial collision and diffusion sedimentation. The final emission is a low-temperature, low-velocity, flameless, and clean gas, thereby eliminating the possibility of secondary fires and secondary injuries caused by joint explosions at the source. This upgrades the safety strategy from "damage reduction" to "proactive hazard elimination," achieving true intrinsic safety.

[0055] Secondly, it greatly expands the applicable scenarios of the device. Traditional pressure relief orifices suffer from unrestrained jetting of flames and high-temperature particles. The ejected flames and high-temperature particles (often exceeding the ignition point of surrounding cable sheaths and insulation materials) can easily ignite nearby cable trays, insulation materials, or other combustibles, causing an initial local fault to escalate into a spreading electrical fire. Their installation locations are strictly limited, typically requiring them to be far from other equipment and personnel activity areas, severely restricting their application scope. This invention completely solves this bottleneck by achieving safe discharge. The directional flow design allows the discharge direction to be preset to a safe area (such as vertically upwards or towards a dedicated pressure relief channel), while the clean discharge characteristic eliminates the hazard source near the device outlet. Therefore, the device of this invention can be safely deployed in densely equipped substation cable layers, narrow tunnel corridors, and even in near-personnel work areas or important facilities where fire protection requirements are extremely high. This broad environmental adaptability allows high-standard safety protection to cover more critical and complex nodes in the power grid, significantly improving the overall system's safety margin.

[0056] Third, it ensures a high degree of controllability and predictability in the explosion venting process. Traditional pressure relief orifices are affected by various random factors such as explosion intensity and product composition, resulting in a chaotic process and unpredictable outcomes. This invention, through a precise integrated structural design, programs and standardizes the explosion venting process. Key parameters such as the guide vane inclination angle and channel area of ​​the first-level unit, and the labyrinth turning stages and channel dimensions of the second-level unit, can be accurately calculated and simulated and optimized based on the principles of fluid mechanics, combustion, and explosion mechanics. This makes core performance indicators such as pressure relief opening and closing pressure, flow rate, pressure decay curve, and quenching efficiency designable, calculable, and verifiable. For example, by adjusting the length and inner wall roughness of the labyrinth channel, the outlet gas temperature can be precisely controlled to drop below a predetermined value. This engineering controllability and predictability not only ensures the reliability and consistency of the device's performance but also provides a solid theoretical basis and design standards for the serialized design of products under different voltage levels and installation environments, greatly enhancing the product's engineering practicality and reliability.

[0057] In summary, this invention not only solves the inherent defects of traditional technology such as "flame accompanied by jetting and diffusion of hazardous products", but also achieves a multi-dimensional leap in safety, applicability and engineering reliability, providing a revolutionary solution for the safety protection of high-voltage cable joints.

[0058] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0059] In this invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be a single item or multiple items.

[0060] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the devices, apparatuses, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0061] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy dissipation module, characterized in that: The flame extinguishing and explosion relief device includes: Protective case; A dual-stage energy dissipation module is disposed on the protective shell, and the dual-stage energy dissipation module is sealed to the composite structure protective shell. The dual-stage energy dissipation module includes: a primary energy dissipation unit and a secondary energy dissipation unit arranged in series; The first-stage energy dissipation unit is equipped with multiple guide vanes along a preset tilt angle to guide the disordered jet into a directional airflow. The secondary energy release unit forms a labyrinthine continuous sealed channel with multiple turning structures, which is used to extinguish the flame and attenuate the airflow pressure.

2. The high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy dissipation module as described in claim 1, characterized in that: The protective shell is a composite structure protective shell, including an upper shell, a lower shell, and a wall. The upper shell and the lower shell are connected by flange edges and connecting bolts. The wall includes an inner lining layer, a structural layer, and an outer layer; The inner lining layer includes an arc-resistant material, the structural layer includes a pressure-bearing material, and the outer layer includes a flame-retardant material.

3. The high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy dissipation module as described in claim 1, characterized in that: The angle between the plurality of guide vanes and the main axis of the airflow is in the range of 30° to 40°; and the thickness of the plurality of guide vanes is between 1 and 3 mm.

4. The high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy dissipation module as described in claim 3, characterized in that: The continuous enclosed channel includes interconnected gradually expanding transition channels and labyrinth channels. The gradually expanding transition channel is positioned corresponding to the positions of the plurality of guide vanes; The cross-section of the maze passage is rectangular and includes at least three passage bends, with bend angles of 90° or 180° at each bend.

5. The high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy dissipation module as described in claim 4, characterized in that: The roughness of the inner wall of the maze passage is Ra>6.3μm.

6. The high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy dissipation module as described in claim 5, characterized in that: The continuous sealed channel also includes a detachable filter plate mounting slot, which is located at the exit of the labyrinth channel and is used to insert a filter plate to filter submicron-level dust; the pore size of the filter plate is between 80 and 300 micrometers.

7. The high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy dissipation module as described in claim 6, characterized in that: The primary energy venting unit and the secondary energy venting unit are connected to each other via connecting flanges, standard interface flanges, and bolts, and a metal spiral wound gasket is also provided at the connection between the primary energy venting unit and the secondary energy venting unit.

8. The high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy dissipation module as described in claim 7, characterized in that: The flame extinguishing and explosion relief device includes at least two dual-stage energy relief modules disposed on the same side of the protective shell.

9. The high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy dissipation module as described in claim 8, characterized in that: The dual-stage energy dissipation module is manufactured using 3D printing. Alternatively, the dual-stage energy dissipation module may be manufactured using precision casting.

10. The operating method of the high-voltage cable joint flame extinguishing and explosion venting device based on a two-stage energy dissipation module as described in any one of claims 1-9, characterized in that: The multiple guide vanes in the primary energy dissipation unit direct the flow of the high-temperature and high-pressure mixed gas generated by the explosion inside the wall and perform preliminary cooling and filtration. The continuous sealed channel in the secondary energy release unit completely extinguishes the treated high-temperature and high-pressure mixed gas and further reduces pressure and filters particulate matter. The flame extinguishing and explosion relief device safely discharges the treated gas.

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