Fire simulation equipment for power cable short circuit

Abstract

The invention provides fire simulation equipment for power cable short circuit. The cable simulation system comprises an experimental cable and a pipe gallery simulation piece, the pipe gallery simulation piece is used for simulating a limited long and narrow environment where a real short-circuit cable is located, the supporting system is arranged in the pipe gallery simulation piece, and the experimental cable is horizontally placed on the supporting system; the heating system is electrically connected with the experimental cable and is used for introducing overload current into the experimental cable, the ignition system can generate molten metal drops, the ignition system is provided with a liquid outlet used for discharging the molten metal drops, and the liquid outlet of the ignition system is located above the experimental cable and enables the molten metal drops to drop on the experimental cable. Therefore, the short-circuit current heat effect and metal droplet ignition simulation reproduction of the experimental cable can be realized. According to the technical scheme, the problem that in the prior art, the accuracy of the simulation effect of fire simulation equipment for power cable short circuit is poor is solved.

Description

Technical Field

[0001] This invention relates to the field of power cable fire simulation technology, and more specifically, to a fire simulation device for power cable short circuits. Background Technology

[0002] With the rapid development of my country's power industry and accelerated urbanization, the scale of cable application has continued to expand, with a total mileage exceeding one million kilometers. The cable coverage rate in the core areas of large cities generally exceeds 90%. Data from the National Fire and Rescue Administration shows that between 2020 and 2022, electrical fires accounted for an average of over 30% of all fires, making it one of the main types of fires in my country. One of the core causes of cable fires is long-term overload operation: current exceeding the rated value leads to abnormal heating of the conductor, and the continuous thermal effect accelerates insulation aging, ultimately causing a short circuit. The high-intensity current generated at the moment of the short circuit causes the conductor temperature to rise sharply, far exceeding the insulation layer's tolerance limit, causing it to melt and burn rapidly. At this time, the molten metal droplets generated at the weak points of the cable can easily ignite nearby insulation materials, forming an uncontrollable fire. Such fires are extremely dangerous, not only causing interruptions in production and public services, equipment damage, and significant property losses, but also accompanied by serious safety risks such as electric shock and poisoning from toxic fumes. For example, in 2017, a workshop in Pengshan, Sichuan, experienced a short circuit and fire caused by long-term cable overload, resulting in direct economic losses of 380,000 yuan. Therefore, in order to effectively prevent cascading accidents, it is urgent to reproduce the cable fire process in a near-realistic scenario (simulating short-circuit current and molten droplet effect), accurately measure key critical parameters such as ignition and spread, and provide a scientific basis for fire prevention and control.

[0003] Several researchers have developed simulation devices for cable fires. Chinese Patent CN119723463B provides an intelligent identification and prevention linkage system for cable fires in integrated utility tunnels. This system uses an adjustable oil pan and a size adjustment unit to simulate cable fires in different locations and specifications within the tunnel space. Chinese Patent CN113823167B provides a cable tunnel fire simulation system. This system simulates the spread of smoke from cable combustion by constructing a cable tunnel fire simulation device. Chinese Patent CN113945243B provides a coupled experimental device and method for simulating the spread of cable fires in the power compartments of urban underground integrated utility tunnels. It ignites the cable with an ignition device, allowing it to self-ignite and spread the fire, simulating mass changes, temperature distribution, wind speed, and flame characteristics during the fire spread process. Chinese Patent CN113848281B provides a simulation device for smoldering and open flame of high-voltage power cables. It uses a heating device and an ignition device to simulate the development process of fire smoke under external heat source conditions for high-voltage power cables. Chinese patent CN112964825B, authorized by patent number CN112964825B, provides a fire source simulation device for igniting cables by faulty electric arcs. It uses high-voltage alternating current to generate a long-length electric arc to ignite the cable, simulating a cable fire caused by a faulty arc. Chinese patent CN111159960B, authorized by patent number CN111159960B, provides a numerical simulation method for cable fault-induced fires in tunnels. It establishes a fire source model of a cable tunnel fire using a FLASH-CAT model to obtain the variation law of fire parameters. Chinese patent CN106290466, authorized by patent number CN106290466, provides a test device for the lateral spread of fire between bundled cables. It uses an adjustable cable fixing device to simulate the lateral spread of fire between bundled cables caused by the ignition of laterally adjacent faulty cables under different faulty cable locations. Chinese patent CN109243279A, published by patent application, provides an experimental device for fire testing in the power compartment of an underground integrated utility tunnel. It simulates a fire in the integrated utility tunnel by collecting data on the non-uniform temperature field within the tunnel during a fire, providing a detailed reflection of the non-uniform temperature field distribution.

[0004] Analysis of existing technologies reveals that most existing technologies rely on external open flames to directly ignite the cable or facilitate the spread of smoke. Although some technologies simulate fault arcs using high-voltage AC power, they do not consider the impact of complex factors such as molten droplets generated at weak points during cable combustion on the entire cable group. Therefore, the accuracy of fire simulation equipment for power cable short circuits in existing technologies is relatively poor. Summary of the Invention

[0005] The main objective of this invention is to provide a fire simulation device for power cable short circuits, in order to solve the problem of poor accuracy in the simulation effect of existing power cable short circuit fire simulation devices.

[0006] To achieve the above objectives, the present invention provides a fire simulation device for power cable short circuits, comprising a cable simulation system, a heating system, an ignition system, a monitoring system, a data acquisition system, a control system, and a support system. The cable simulation system includes an experimental cable and a pipe gallery simulation component. The pipe gallery simulation component is a shell structure with internal channels, used to simulate the confined and narrow environment of a real short-circuited cable. The support system is disposed within the pipe gallery simulation component, and the experimental cable is placed horizontally on the support system. The heating system is disposed on the support system, electrically connected to the experimental cable, and used to supply an overload current to the experimental cable. The ignition system generates molten metal droplets and has an outlet for discharging the molten metal droplets. The outlet of the ignition system is located above the experimental cable, causing the molten metal droplets to fall onto the experimental cable, thereby simulating and reproducing the short-circuit current thermal effect of the experimental cable and the ignition of the molten metal droplets. At least part of the monitoring system is located within the pipe gallery simulation component, used to monitor the morphological changes of the experimental cable during combustion within the pipe gallery simulation component. The data acquisition system is electrically connected to the monitoring system and used to collect simulated state information of the experimental cable. The heating system, ignition system, and data acquisition system are all connected to the control system.

[0007] Furthermore, the ignition system includes a droplet simulation device and a power supply device. The power supply device is electrically connected to the droplet simulation device to supply a short-circuit current to the droplet simulation device, so that the droplet simulation device generates metal droplets and drips the metal droplets onto the experimental cable through the outlet.

[0008] Furthermore, the ignition system also includes a sliding assembly, which includes a fixing member and a slide rail. The fixing member is mounted on the support system, and the slide rail is movably mounted on the fixing member along the axial direction of the experimental cable. The molten droplet simulation device is mounted on the slide rail to enable translation of the molten droplet simulation device.

[0009] Furthermore, the droplet simulation device includes a component to be heated, a heating coil, and a coil support. The coil support has a accommodating space and a liquid outlet communicating with the accommodating space. The component to be heated is located within the accommodating space. The component to be heated is used to simulate the weak points of a real short-circuited cable that generate molten metal droplets. The heating coil is wound around the coil support. The heating coil is used to simulate the thermal effect of the cable short-circuit current and heat the component to be heated, so that the component to be heated generates molten metal droplets and discharges the molten metal droplets from the liquid outlet.

[0010] Furthermore, the power supply device includes a first power source, a current controller, a first switch, and a power transmission cable. The first switch, the current controller, the first power source, and the heating coil are electrically connected through the power transmission cable to form a closed loop. The current controller is used to convert the current output by the first power source into a short-circuit current and adjust the magnitude of the short-circuit current. The first switch is used to control the on / off state of the current in the power transmission cable.

[0011] Furthermore, the heating system includes a second power supply, a power controller, a second switch, and an experimental simulation circuit. The power controller, the second power supply, the second switch, and the experimental cable are electrically connected through the experimental simulation circuit to form a closed loop. The power controller is used to convert the current output by the second power supply into a short-circuit current and adjust the magnitude of the short-circuit current. The second switch is used to control the current flow of the experimental simulation circuit.

[0012] Furthermore, the monitoring system includes multiple thermocouples, which are spaced apart along the circumference and / or axial direction of the experimental cable to measure the temperature distribution in different areas of the experimental cable. All thermocouples are electrically connected to the acquisition system to collect temperature data during the simulation process of the experimental cable.

[0013] Furthermore, the monitoring system also includes a video monitoring device and an infrared monitoring device. The video monitoring device is located inside the pipe gallery simulation component and is used to record the morphological changes and combustion process of the experimental cable during the simulation. The infrared monitoring device is located at one end of the internal channel of the pipe gallery simulation component and is used to record the fire spread during the experimental cable simulation. Both the video monitoring device and the infrared monitoring device are electrically connected to the acquisition system to acquire real-time data and images during the experimental cable simulation.

[0014] Furthermore, the support system includes a fixing device and an adjustment device. The adjustment device includes: multiple lifting modules, which are spaced apart on the fixing device along the axial direction of the experimental cable, and the lifting modules are movably arranged relative to the fixing device along the height direction of the fixing device; and multiple limiting modules, which are correspondingly arranged on the multiple lifting modules, and the limiting modules have limiting spaces for fixing the experimental cable, and the size of the limiting spaces is adjustable.

[0015] Furthermore, the fixing device includes two fixed supports, each including a crossbar and columns. The crossbar is set on the pipe gallery simulation component, and each crossbar is equipped with multiple columns. The adjusting device also includes a translation module. Each column is slidably connected to the crossbar through the translation module. One end of the multiple lifting modules is set one-to-one with the multiple columns of one of the two fixed supports, and the other end of the multiple lifting modules is set one-to-one with the multiple columns of the other fixed support.

[0016] By applying the technical solution of this invention, a heating system and an ignition system are set up. The heating system can short-circuit the experimental cable and generate a thermal effect, thereby simulating and reproducing the thermal effect generated by the short-circuit current when the cable is short-circuited. The ignition system can generate molten metal droplets and drop them onto the surface of the experimental cable, simulating and reproducing the fire spread caused by the molten metal droplets igniting the insulation layer at the weak part of the short-circuited cable. In this way, by using the combined action of the heating system and the ignition system to ignite the experimental cable and reproduce the combustion process of a real power cable fire, the process of a fire caused by a cable short circuit can be realistically simulated, thereby improving the accuracy of the simulation effect of the power cable short circuit fire simulation equipment. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A schematic diagram of an embodiment of the fire simulation device for power cable short circuit of the present invention is shown;

[0019] Figure 2 It shows Figure 1 A schematic diagram of the ignition system of a fire simulation device for power cable short circuits;

[0020] Figure 3 It shows Figure 1 A fire simulation experiment diagram of a physical fire simulation device for simulating a short circuit in a power cable.

[0021] The above figures include the following reference numerals:

[0022] 110. Experimental cable; 120. Pipe gallery simulation component; 210. Fixing device; 211. Column; 212. Crossbar; 220. Adjustment device; 221. Limiting module; 222. Lifting module; 223. Translation module; 310. Power controller; 320. Second power supply; 330. Second switch; 340. Experimental simulation circuit; 410. Molten droplet simulation device; 411. Component to be heated; 412. Heating coil; 413. Coil support; 414. Liquid outlet; 420. Power supply device; 421. First power supply; 422. Current controller; 423. First switch; 424. Power supply cable; 430. Molten metal droplet; 440. Slide rail; 450. Fixing component; 510. Monitoring system; 511. Infrared monitoring device; 512. Thermocouple; 513. Video monitoring device; 600. Acquisition system; 700. Control system. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0025] like Figures 1 to 3 As shown, an embodiment of the present invention provides a fire simulation device for power cable short circuits, including a cable simulation system, a heating system, an ignition system, a monitoring system 510, a data acquisition system 600, a control system 700, and a support system. The cable simulation system includes an experimental cable 110 and a pipe gallery simulation component 120. The pipe gallery simulation component 120 is a shell structure with internal channels. The pipe gallery simulation component 120 is used to simulate the confined and narrow environment of a real short-circuited cable. The support system is disposed within the pipe gallery simulation component 120, and the experimental cable 110 is placed horizontally on the support system. The heating system is disposed on the support system, electrically connected to the experimental cable 110, and used to supply an overload current to the experimental cable 110. The ignition system is capable of generating... The ignition system has an outlet 414 for discharging the molten metal droplets 430. The outlet 414 of the ignition system is located above the experimental cable 110 and causes the molten metal droplets 430 to drip onto the experimental cable 110, so as to realize the short-circuit current thermal effect of the experimental cable 110 and the simulation reproduction of the ignition of the molten metal droplets 430. At least part of the monitoring system 510 is located inside the pipe gallery simulation component 120. The monitoring system 510 is used to monitor the morphological changes of the experimental cable 110 when it burns inside the pipe gallery simulation component 120. The acquisition system 600 is electrically connected to the monitoring system 510 and is used to acquire the simulated state information of the experimental cable 110. The heating system, the ignition system and the acquisition system 600 are all connected to the control system 700.

[0026] In the above technical solution, by setting up a heating system and an ignition system, the heating system can short-circuit the experimental cable and generate a thermal effect, thereby simulating and reproducing the thermal effect generated by the short-circuit current when the cable is short-circuited. The ignition system can generate molten metal droplets 430 and drip them onto the surface of the experimental cable, simulating and reproducing the fire spread caused by the molten metal droplets 430 igniting the insulation layer at the weak point of the short-circuited cable. In this way, by using the combined action of the heating system and the ignition system to ignite the experimental cable and reproduce the combustion process of a real power cable fire, the process of a fire caused by a cable short circuit can be realistically simulated, thereby improving the accuracy of the simulation effect of the power cable short circuit fire simulation equipment.

[0027] Furthermore, the support system is mainly used to fix the experimental cable to prevent uncontrollable displacement from interfering with the experimental results during the experiment, so as to ensure the accuracy of the experiment.

[0028] Furthermore, the monitoring system 510 can record the combustion process and fire spread, and transmit the data to the control system 700 through the acquisition system 600, thereby facilitating observation by operators.

[0029] Specifically, the cable simulation system can simulate the layout of actual underground power cables; the support system can fix and adjust the position of the experimental cable; the heating system is located outside the cable system and connected to the experimental cable, simulating a real cable short circuit scenario; the ignition system directly applies molten metal droplets to the experimental cable to ignite it; the monitoring system can detect changes in temperature and flame shape inside the cable simulation system in real time; the acquisition system can collect monitoring data from the monitoring system; and the control system can intelligently control the position of the experimental cable, the start and stop of the heating system and the ignition system.

[0030] In some embodiments, the extension direction of the internal channel is the same as the axial direction of the experimental cable, i.e. Figure 1 The left and right directions in the middle.

[0031] It should be noted that overload current refers to the current flowing through the circuit exceeding the rated load-bearing capacity of the test cable.

[0032] In some embodiments, both the acquisition system 600 and the control system 700 are located outside the pipe gallery simulation component 120.

[0033] In some embodiments, the experimental cable 110 is a horizontally placed cylinder for passing short-circuit current and receiving molten metal droplets 430, thereby simulating and reproducing the short-circuit current thermal effect of the power cable and the ignition of the molten metal droplets 430. The pipe gallery simulation component 120 is a horizontally placed cuboid with internal through holes, thereby simulating the limited and narrow environment in which the cable is located.

[0034] In some embodiments, the experimental cable 110 is a real cable, and the specific cable model and length are determined according to the actual simulation requirements, without specific restrictions here.

[0035] In some embodiments, the pipe gallery simulation component 120 may be made of Q235 carbon steel, and surface reinforcement measures should be taken around it to improve its surface fatigue strength, so that it can withstand the high temperature when the cable is burning and the pressure generated by the arc impact or local explosion during the cable short circuit, and prevent the cable burning from causing damage or deformation to the pipe gallery simulation component 120.

[0036] It should be noted that a finite and elongated environment generally refers to the working or experimental environment of an object or system in a space where the length is much greater than the width and height. In the field of electrical engineering, the environment of underground cable facilities, power tunnels, or utility corridor systems is a finite and elongated environment.

[0037] like Figures 1 to 3 As shown, in an embodiment of the present invention, the ignition system includes a droplet simulation device 410 and a power supply device 420. The power supply device 420 is electrically connected to the droplet simulation device 410 to supply a short-circuit current to the droplet simulation device 410 so that the droplet simulation device 410 generates metal droplets 430 and drips the metal droplets 430 onto the experimental cable 110 through the liquid outlet 414.

[0038] In the above technical solution, the power supply device 420 is used to provide short-circuit current to the droplet simulation device 410 to simulate the thermal effect of short-circuit current in the weak part of the power cable. This enables the simulation and reproduction of the ignition of metal droplets in the weak part of the power cable, that is, to simulate the ignition effect of droplets generated by the power cable under the short-circuit thermal effect, thus reproducing the real scene of cable fire and improving the accuracy and realism of fire simulation.

[0039] like Figures 1 to 3 As shown, in an embodiment of the present invention, the ignition system further includes a sliding assembly, which includes a fixing member 450 and a slide rail 440. The fixing member 450 is disposed on the support system, and the slide rail 440 is movably disposed on the fixing member 450 along the axial direction of the experimental cable 110. The molten droplet simulation device 410 is disposed on the slide rail 440 so that the molten droplet simulation device 410 can be translated.

[0040] With the above settings, the position of the molten metal droplets 430 dripping on the experimental cable can be changed by moving the slide rail 440, thereby simulating the spread of fire ignited by the molten metal droplets 430 at different locations on the experimental cable, thus improving the accuracy and realism of the fire simulation.

[0041] In some embodiments, the power supply device 420 is not mounted on the slide rail 440, and the droplet simulation device 410 is connected to the power supply device 420 via a soft copper cable to accommodate the range of motion of the droplet simulation device 410. Alternatively, the power supply device 420 may be mounted on the slide rail 440 so that the power supply device 420 and the droplet simulation device 410 can move together.

[0042] In some embodiments, the sliding assembly further includes a drive motor and a lead screw and nut assembly to achieve automatic control of the slide rail 440. The specific connection method can adopt existing technology, which will not be described in detail here.

[0043] like Figures 1 to 3 As shown, in an embodiment of the present invention, the droplet simulation device 410 includes a component to be heated 411, a heating coil 412, and a coil support 413. The coil support 413 has a receiving space and a liquid outlet 414 communicating with the receiving space. The component to be heated 411 is located in the receiving space. The component to be heated 411 is used to simulate the weak part of the metal droplet 430 generated by a real short-circuited cable. The heating coil 412 is wound on the coil support 413. The heating coil 412 is used to simulate the thermal effect of the cable short-circuit current and heat the component to be heated 411, so that the component to be heated 411 generates metal droplets 430 and discharges the metal droplets 430 from the liquid outlet 414.

[0044] With the above settings, the heating coil 412 heats the component 411 to be heated, simulating the thermal effect of a cable short circuit, thereby generating molten metal droplets 430. This replicates the process of generating molten metal droplets 430 at the weak point of the cable. The molten metal droplets 430 can then drip onto the experimental cable through the outlet. Thus, the droplet simulation device 410 can simulate and reproduce the scenario where molten metal droplets 430 are generated at the weak point of the power cable due to the thermal effect of the short circuit current and fall to ignite the power cable, thereby improving the accuracy and realism of the fire simulation.

[0045] In some embodiments, the element to be heated 411 is the material to be heated, which may be a cable or other material. Preferably, the material to be heated is a real cable shell. The specific cable model and length are determined according to the actual simulation requirements and are not specifically limited here.

[0046] In some embodiments, the heating coil 412 is a cylindrical conductive winding that can convert electrical energy into heat energy to simulate the thermal effect of a cable short-circuit current and heat the material to be heated. The coil support 413 is a funnel-shaped shell used to wind the heating coil 412 and support the material to be heated. The side walls of the accommodating space of the coil support 413 are attached with metal heating rods, and each heating rod is evenly and tightly wound with the heating coil 412. The liquid outlet 414 is used for molten droplets to ignite the experimental cable 110. The heating coil 412 can be made of solid thick copper wire. The specific coil specifications are determined according to the specifications of the cable to be heated in the actual simulation requirements, and no specific restrictions are made here.

[0047] like Figures 1 to 3 As shown, in an embodiment of the present invention, the power supply device 420 includes a first power supply 421, a current controller 422, a first switch 423, and a power transmission cable 424. The first switch 423, the current controller 422, the first power supply 421, and the heating coil 412 are electrically connected through the power transmission cable 424 to form a closed loop. The current controller 422 is used to convert the current output by the first power supply 421 into a short-circuit current and adjust the magnitude of the short-circuit current. The first switch 423 is used to control the on / off state of the current in the power transmission cable 424.

[0048] In the above technical solution, the first power supply 421 can provide an external power supply to the current controller 422 to maintain the operation of the current controller 422, thereby adjusting the magnitude of the short-circuit current. The power supply cable 424 efficiently transmits the short-circuit current to the heating coil 412 to provide an adjustable short-circuit current to the heating coil 412, thereby providing a heat source with an adjustable temperature to the material to be heated. At the same time, the first switch 423 is used to control the switching of the current in the ignition system, thereby controlling the start and end of the simulation experiment.

[0049] In some embodiments, the first power supply 421 may be selected from industrial three-phase AC power (the most cost-effective), a dedicated large-capacity generator (portable), etc. The specific power supply selection is determined according to the actual simulation requirements, and no specific restrictions are made here.

[0050] In some embodiments, the first power supply 421 may be a 220V / 330V AC power supply. The specific power supply selection is determined according to the specifications of the heating coil 412, and no specific restrictions are made here.

[0051] In some embodiments, the current controller 422 is specifically selected based on the specifications of the heating coil 412, and no specific restrictions are imposed here.

[0052] In some embodiments, the first switch 423 may be a high-current contactor or the like, and the specific choice depends on the specifications of the heating coil 412. No specific restrictions are made here.

[0053] In some embodiments, the power supply cable 424 may be a multi-strand soft copper cable, etc. The specific selection depends on the specifications of the heating coil 412, and no specific restrictions are made here.

[0054] like Figures 1 to 3As shown, in an embodiment of the present invention, the heating system includes a second power supply 320, a power controller 310, a second switch 330, and an experimental simulation circuit 340. The power controller 310, the second power supply 320, the second switch 330, and the experimental cable 110 are electrically connected through the experimental simulation circuit 340 to form a closed loop. The power controller 310 is used to convert the current output by the second power supply 320 into a short-circuit current and adjust the magnitude of the short-circuit current. The second switch 330 is used to control the current switching on and off of the experimental simulation circuit 340.

[0055] In the above technical solution, the power controller 310 is used to convert the current output by the second power supply 320 into a short-circuit current and adjust the magnitude of the short-circuit current. This avoids current runaway and ensures experimental safety. The adjusted short-circuit current is efficiently transmitted to the experimental cable 110 through the experimental simulation circuit 340, causing the experimental cable to short-circuit and generate a thermal effect. This can simulate and reproduce the thermal effect generated by the short-circuit current when the cable is short-circuited, and can realistically simulate the process of a fire caused by a cable short circuit. In this way, the accuracy of the simulation effect of the fire simulation equipment for power cable short circuit can be improved.

[0056] Furthermore, the second power supply 320 is used to provide external power to the power controller 310 to maintain the operation of the power controller 310, and the second switch 330 is used to control the current flow of the experimental cable.

[0057] In some embodiments, the heating system is located outside the tube gallery simulator 120, and the two ends of the experimental simulation circuit 340 enter the internal channel through the two end openings of the internal channel of the tube gallery simulator 120 and are electrically connected to the two ends of the experimental cable 110.

[0058] In some embodiments, combined with Figure 2 and Figure 3 As shown, the heating system and the ignition system work together to ignite and reproduce the combustion process of a real power cable fire. The heating system adjusts the short-circuit current through the second power supply 320 and the power controller 310 to short-circuit the experimental cable and generate a thermal effect. The ignition system heats the droplet simulation device 410 through the power supply device 420 to generate molten metal droplets 430, which drip onto the surface of the experimental cable 110 to provide a heat source. The two work together to ignite the experimental cable 110 and reproduce the fire accident scene caused by the short circuit of the power cable.

[0059] In some embodiments, the second power supply 320 may be selected from industrial three-phase AC power (the most cost-effective), a dedicated large-capacity generator (portable), etc. The specific power supply selection is determined according to the actual simulation requirements, and no specific restrictions are made here.

[0060] In some embodiments, the power controller 310 may be an adjustable high-current generator, an autotransformer, etc. The specific selection depends on the actual analog current type and magnitude, and no specific restrictions are made here.

[0061] In some embodiments, the second switch 330 may be a high-current contactor, etc. The specific selection depends on the actual type and magnitude of the analog current, and no specific restrictions are imposed here.

[0062] In some embodiments, the experimental simulation circuit 340 may be made of multi-strand soft copper cable (high current carrying capacity) or large-section multi-strand copper core soft cable (easy to move or bend frequently). The insulation layer may be made of cross-linked polyethylene (temperature resistant 100~200 degrees Celsius) and does not need to be too thick.

[0063] It should be noted that the current carrying capacity of the experimental simulation circuit 340 is no less than 1.2 times the maximum experimental current, and its length is as short as possible to ensure that the current is efficiently transferred to the experimental cable. At the same time, it avoids overheating of the experimental simulation circuit 340 itself, which could cause safety problems, and can be reused multiple times.

[0064] like Figures 1 to 3 As shown in the embodiment of the present invention, the monitoring system 510 includes multiple thermocouples 512, which are spaced apart along the circumference and / or axial direction of the experimental cable 110 to measure the temperature distribution in different areas of the experimental cable 110. All thermocouples 512 are electrically connected to the acquisition system 600 to collect temperature data during the simulation process of the experimental cable 110. This allows for the measurement of the temperature distribution in different areas of the experimental cable 110, thereby improving the accuracy of the simulation effect of the fire simulation equipment for power cable short circuits.

[0065] In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0066] In some embodiments, the number and placement of thermocouples 512 depend on the actual needs of the fire simulation and are not specifically limited here.

[0067] In some embodiments, thermocouples 512 should preferably be type K thermocouples, and their number depends on the length of the test cable 110. It is advisable to ensure that there is a set of thermocouples 512 every 0.3m to 1m of the test cable 110.

[0068] In some embodiments, the circuit of thermocouple 512 should be protected by a protective sleeve to protect the normal function of the thermocouple 512 circuit.

[0069] In some specific embodiments, thermocouples 512 are arranged on and above the experimental cable 110. Multiple thermocouples can be arranged in the vertical and horizontal directions according to the height and length of the pipe gallery simulation component 120, so as to obtain temperature data at different locations above the experimental cable 110.

[0070] like Figures 1 to 3As shown in the embodiment of the present invention, the monitoring system 510 further includes a video monitoring device 513 and an infrared monitoring device 511. The video monitoring device 513 is located inside the pipe gallery simulation component 120 and is used to record the morphological changes of the experimental cable 110 during the simulation process and the combustion process of the experimental cable 110 during the simulation. The infrared monitoring device 511 is located at one end of the internal channel of the pipe gallery simulation component 120 and is used to record the fire spread during the simulation process of the experimental cable 110. Both the video monitoring device 513 and the infrared monitoring device 511 are electrically connected to the acquisition system 600 to acquire real-time data information and images during the simulation process of the experimental cable 110.

[0071] In the above technical solution, the video monitoring device 513 and the infrared monitoring device 511 can record the morphological changes, combustion process and fire spread of the experimental cable. At the same time, both the video monitoring device 513 and the infrared monitoring device 511 are electrically connected to the acquisition system, which can collect real-time data and images during the simulation process of the experimental cable 110, so as to provide experimental data for studying the fire spread when the cable is short-circuited.

[0072] In some embodiments, the infrared monitoring device 511 and the video monitoring device 513 can adjust their height and angle to capture images of the combustion inside the pipe gallery simulation component 120, which is beneficial for subsequent related analysis.

[0073] In some embodiments, the video monitoring device 513 is preferably a water-cooled camera that can withstand the high-temperature environment when the cable is burning; the infrared monitoring device 511 is preferably an infrared camera.

[0074] In some embodiments, multiple infrared monitoring devices 511 and video monitoring devices 513 may be set according to specific simulation requirements, without specific limitations.

[0075] In some embodiments, the acquisition system 600 is mainly used to acquire real-time data information and image images of thermocouple 512, video monitoring device 513, and infrared monitoring device 511, so as to acquire the simulated status information of experimental cable 110. The simulated status information includes the fire spread situation, real-time data information, image and temperature data information during the simulation process.

[0076] In some embodiments, the acquisition system 600 may be selected from multi-channel temperature acquisition modules, NVRs (Network Video Recorders), etc. The specific selection is determined according to the actual simulation requirements, and no specific restrictions are made here.

[0077] In some embodiments, the video monitoring device is located on the front and sides of the experimental cable to record the flame pattern and combustion process during the experimental cable fire simulation; the infrared monitoring device is used to observe and record the temperature changes during the experimental cable fire.

[0078] In some embodiments, the infrared monitoring device 511 is located outside the opening of the internal passage of the pipe gallery simulation 120, and the lens of the infrared monitoring device 511 is set towards the opening to detect the internal conditions of the pipe gallery simulation 120.

[0079] like Figures 1 to 3 As shown, in an embodiment of the present invention, the support system includes a fixing device 210 and an adjusting device 220. The adjusting device 220 includes: a plurality of lifting modules 222, which are spaced apart on the fixing device 210 along the axial direction of the experimental cable 110, and the lifting modules 222 are movably arranged relative to the fixing device 210 along the height direction of the fixing device 210; and a plurality of limiting modules 221, which are correspondingly arranged on the plurality of lifting modules 222, and the limiting modules 221 have a limiting space for fixing the experimental cable 110, and the size of the limiting space is adjustable.

[0080] In the above technical solution, the experimental cable 110 is fixed on the limiting module 221. The limiting module 221 can fix experimental cables 110 of different diameters. The lifting module 222 can drive the experimental cable 110 on the limiting module 221 to rise and fall, thereby adjusting the height difference between the experimental cable 110 and the ignition system. This allows for adjustment of the temperature of the molten droplets falling on the experimental cable 110, thereby improving the accuracy of the simulation effect of the fire simulation equipment for power cable short circuit.

[0081] In some embodiments, the lifting module 222 mainly consists of a motor as the drive unit, connected to the cable support platform via a lead screw and nut transmission mechanism. Combined with a vertical guide rail and a slider assembly, it ensures the cable support platform rises or falls stably along the guide rail. A limit module 221 is installed on the cable support platform. The entire lifting process is embedded in the closed-loop control of the control system. The operator can set the required height and lifting speed via a touch panel and monitor the cable position in real time, ensuring the controllability and repeatability of experimental conditions. The specific structure of the lifting module 222 can utilize existing technology and will not be described in detail here.

[0082] In some embodiments, the limiting module 221 includes a drive motor directly connected to a lead screw. The lead screw has two jaws, and the position and force of the two jaws are adjusted by rotating the lead screw. These components work together to adapt to and firmly fix experimental cables 110 of different diameters and materials, ensuring they remain in place under heating and molten droplet action, preventing displacement due to thermal expansion or external forces. The specific structure of the limiting module 221 can employ existing technology and will not be described in detail here.

[0083] like Figures 1 to 3As shown in the embodiment of the present invention, the fixing device 210 includes two fixing brackets, each including a crossbar 212 and a column 211. The crossbar 212 is disposed on the pipe gallery simulation component 120, and each crossbar 212 is provided with multiple columns 211. The adjusting device 220 also includes a translation module 223. Each column 211 is slidably connected to the crossbar 212 through the translation module 223. One end of multiple lifting modules 222 is correspondingly disposed with multiple columns 211 of one of the two fixing brackets, and the other end of multiple lifting modules 222 is correspondingly disposed with multiple columns 211 of the other fixing bracket.

[0084] In the above technical solution, the fixed bracket can prevent the experimental cable from undergoing uncontrollable displacement during the experiment, and the translation module 223 can make the experimental cable 110 translate along its own axis, so that the support system can adapt to experimental cables 110 of different lengths, thereby increasing the adaptability of the fire simulation equipment for power cable short circuits and improving the accuracy of the simulation effect of the fire simulation equipment for power cable short circuits.

[0085] In some embodiments, the translation module 223 includes a guide rail, on which a motor-driven moving platform is mounted. Rollers or sliders are located below the moving platform to ensure smooth movement along the guide rail. A column is mounted on the moving platform, and the guide rail is mounted on a crossbar. The specific structure of the translation module 223 can employ existing technology, and will not be described in detail here.

[0086] In some embodiments, such as Figure 1 As shown, the control system 700 can be used to control the movement of the limit module and the translation module 223 in the support system to simulate cable fire scenarios of different types and lengths; the control system 700 can be used to control the amount of current provided by the heating system, thereby controlling the heat generated by the experimental cable 110 due to the current; the control system 700 can also be used to control the current of the power supply device 420, and the molten droplet simulation device 410 can be replaced by a flame torch. The control system 700 controls the height of the flame torch, thereby controlling the speed at which the molten metal droplets 430 drip from the molten droplet simulation device 410; the control system 700 can also be used to control the slide rail 4 The movement of the 40 module simulates the burning of the experimental cable 110 under the action of molten droplets at different positions. The control system 700 can also be used to acquire real-time data and simulation images recorded by the acquisition system 600. The control system can also be used to control the movement of the lifting module, thereby controlling the vertical distance between the experimental cable and the molten droplet simulation device 410, and simulating the burning process of the experimental cable under different molten droplet temperatures. In this way, the control system can control and adjust the position of the experimental cable, the position of the molten metal droplets, and the intensity of the short-circuit current thermal effect, so as to realize the simulation and reproduction of the thermal effect and fire spread of the short-circuit power cable under the action of molten metal droplets in a limited and narrow environment.

[0087] This invention proposes a physical fire simulation device for power cable short circuits. This device can simulate the ignition process, morphological changes, and combustion process of the cable under the action of short-circuit current and molten metal droplets, and characterize the state information before and after combustion. It can provide a reference for power cable fire prediction research, and provide experimental support for the formulation of underground cable fire prevention and control strategies.

[0088] It is understood that by setting up the aforementioned device, the present invention can fully understand the simulation process of underground power cable fires, and can be used as a simulation instrument for experimental research and risk analysis of underground cable fires, providing experimental support for the formulation of underground cable fire prevention strategies.

[0089] Figure 1 and Figure 3 The above illustration shows 10 thermocouples, but those skilled in the art will understand after reading the above technical solution that the solution can be applied to other numbers of thermocouples, which would also fall within the scope of protection of this invention.

[0090] The principle of short-circuit current heating of the heating device in the physical fire simulation device for power cable short circuit according to an embodiment of the present invention is known to those skilled in the art and will not be described in detail here.

[0091] Therefore, this invention can simulate the combustion process of different types of cables by the combined effect of short-circuit current and molten droplets generated during cable combustion, measure critical parameters such as temperature and current when the cable is ignited under short-circuit conditions, and observe and record the cable combustion situation. This invention achieves the simulation and reproduction of the spread of fire caused by ignition under the influence of complex factors such as short-circuit current and molten metal droplets generated at weak points when a power cable experiences a short circuit in a confined and narrow space.

[0092] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects: By setting up a heating system and an ignition system, the heating system can short-circuit the experimental cable and generate a thermal effect, so as to simulate and reproduce the thermal effect generated by the short-circuit current when the cable is short-circuited. The ignition system can generate molten metal droplets and drop them onto the surface of the experimental cable, which can simulate and reproduce the fire spread caused by the ignition of the insulation layer by the molten metal droplets at the weak part of the short-circuited cable. In this way, by using the combined action of the heating system and the ignition system to ignite the experimental cable and reproduce the burning process of a real power cable fire, the process of a fire caused by a cable short circuit can be realistically simulated, thereby improving the accuracy of the simulation effect of the fire simulation equipment for power cable short circuits.

[0093] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0094] In the description of this specification, references to terms such as "embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fire simulation device for power cable short circuit, characterized in that, It includes a cable simulation system, a heating system, an ignition system, a monitoring system (510), a data acquisition system (600), a control system (700), and a support system; The cable simulation system includes an experimental cable (110) and a pipe gallery simulation component (120). The pipe gallery simulation component (120) is a shell structure with an internal channel. The pipe gallery simulation component (120) is used to simulate the limited and narrow environment where a real short-circuited cable is located. The support system is set inside the pipe gallery simulation component (120), and the experimental cable (110) is placed horizontally on the support system. The heating system is mounted on the support system and is electrically connected to the experimental cable (110) and is used to supply an overload current to the experimental cable (110). The ignition system is capable of generating molten metal droplets (430). The ignition system has an outlet (414) for discharging the molten metal droplets (430). The outlet (414) of the ignition system is located above the experimental cable (110) and causes the molten metal droplets (430) to fall onto the experimental cable (110) to realize the short-circuit current thermal effect of the experimental cable (110) and the simulation reproduction of the ignition of the molten metal droplets (430). At least part of the monitoring system (510) is located inside the pipe gallery simulation component (120). The monitoring system (510) is used to monitor the morphological changes of the experimental cable (110) when it is burning inside the pipe gallery simulation component (120). The acquisition system (600) is electrically connected to the monitoring system (510) and is used to acquire the simulated state information of the experimental cable (110). The heating system, the ignition system and the acquisition system (600) are all controlled and connected to the control system (700).

2. The fire simulation device for power cable short circuit according to claim 1, characterized in that, The ignition system includes a droplet simulation device (410) and a power supply device (420). The power supply device (420) is electrically connected to the droplet simulation device (410) to supply a short-circuit current to the droplet simulation device (410) so that the droplet simulation device (410) generates the metal droplet (430) and drips the metal droplet (430) onto the experimental cable (110) through the outlet (414).

3. The fire simulation device for power cable short circuit according to claim 2, characterized in that, The ignition system also includes a sliding assembly comprising a fixing member (450) and a slide rail (440). The fixing member (450) is disposed on the support system, and the slide rail (440) is movably disposed on the fixing member (450) along the axial direction of the experimental cable (110). The molten droplet simulation device (410) is disposed on the slide rail (440) to enable translation of the molten droplet simulation device (410).

4. The fire simulation device for power cable short circuit according to claim 2, characterized in that, The droplet simulation device (410) includes a heating element (411), a heating coil (412), and a coil support (413). The coil support (413) has a accommodating space and a liquid outlet (414) communicating with the accommodating space. The heating element (411) is located in the accommodating space. The heating element (411) is used to simulate the weak part of a real short-circuited cable to generate a metal droplet (430). The heating coil (412) is wound on the coil support (413). The heating coil (412) is used to simulate the thermal effect of the cable short-circuit current and heat the heating element (411) so that the heating element (411) generates a metal droplet (430) and discharges the metal droplet (430) from the liquid outlet (414).

5. The fire simulation device for power cable short circuit according to claim 4, characterized in that, The power supply device (420) includes a first power source (421), a current controller (422), a first switch (423), and a power transmission cable (424). The first switch (423), the current controller (422), the first power source (421), and the heating coil (412) are electrically connected through the power transmission cable (424) to form a closed loop. The current controller (422) is used to convert the current output by the first power source (421) into a short-circuit current and adjust the magnitude of the short-circuit current. The first switch (423) is used to control the on / off state of the current in the power transmission cable (424).

6. The fire simulation device for power cable short circuit according to claim 1, characterized in that, The heating system includes a second power supply (320), a power controller (310), a second switch (330), and an experimental simulation circuit (340). The power controller (310), the second power supply (320), the second switch (330), and the experimental cable (110) are electrically connected through the experimental simulation circuit (340) to form a closed loop. The power controller (310) is used to convert the current output by the second power supply (320) into a short-circuit current and adjust the magnitude of the short-circuit current. The second switch (330) is used to control the current switching on and off of the experimental simulation circuit (340).

7. The fire simulation device for power cable short circuit according to any one of claims 1 to 6, characterized in that, The monitoring system (510) includes multiple thermocouples (512), which are spaced apart along the circumference and / or axial direction of the experimental cable (110) to measure the temperature distribution in different areas of the experimental cable (110). All of the thermocouples (512) are electrically connected to the acquisition system (600) to acquire temperature data information of the experimental cable (110) during the simulation process.

8. The fire simulation device for power cable short circuit according to any one of claims 1 to 6, characterized in that, The monitoring system (510) further includes a video monitoring device (513) and an infrared monitoring device (511). The video monitoring device (513) is located inside the pipe gallery simulation component (120) and is used to record the morphological changes of the experimental cable (110) during the simulation process and the combustion process of the experimental cable (110) during the simulation. The infrared monitoring device (511) is located at one end of the internal channel of the pipe gallery simulation component (120) and is used to record the fire spread during the simulation process of the experimental cable (110). Both the video monitoring device (513) and the infrared monitoring device (511) are electrically connected to the acquisition system (600) to acquire real-time data information and images during the simulation process of the experimental cable (110).

9. The fire simulation device for power cable short circuit according to any one of claims 1 to 6, characterized in that, The support system includes a fixing device (210) and an adjusting device (220), the adjusting device (220) comprising: Multiple lifting modules (222) are spaced apart on the fixing device (210) along the axial direction of the experimental cable (110), and the lifting modules (222) are movably arranged relative to the fixing device (210) along the height direction of the fixing device (210). Multiple limiting modules (221) are provided one-to-one on multiple lifting modules (222). Each limiting module (221) has a limiting space for fixing the experimental cable (110), and the size of the limiting space is adjustable.

10. The fire simulation device for power cable short circuit according to claim 9, characterized in that, The fixing device (210) includes two fixing brackets, each fixing bracket including a crossbar (212) and a column (211). The crossbar (212) is set on the pipe gallery simulation component (120), and each crossbar (212) is provided with a plurality of columns (211). The adjusting device (220) also includes a translation module (223). Each column (211) is slidably connected to the crossbar (212) through the translation module (223). One end of the plurality of lifting modules (222) is set one-to-one with the plurality of columns (211) of one of the two fixing brackets, and the other end of the plurality of lifting modules (222) is set one-to-one with the plurality of columns (211) of the other fixing bracket.

Images