A test device for simulating the ignition of a combustible by a high temperature molten bead

Abstract

The application discloses a kind of simulation high-temperature molten bead ignites combustible test device, including control cabinet, heating furnace and environment simulation component, environment simulation component includes environment simulation bin, inside the environment simulation bin is equipped with speed-regulating fan, ultrasonic humidifier, heat radiation plate, lifting platform, the upper end of the lifting platform is connected with adjustable angle fuel bed, the upper end of control cabinet is connected with mechanical arm, the front end of the mechanical arm is connected with crucible;When carrying out initial speed ignition test, initial speed test mechanism is further provided in the environment simulation bin, and the initial speed test mechanism includes mounting bracket, the mounting bracket is provided with program-controlled launch component and photoelectric speed measuring component, the program-controlled launch component is used to adjust the launch speed of molten bead, and the photoelectric speed measuring component is used to measure the launch speed of molten bead.The application realizes the flexible, fast switching of two test modes of initial speed free fall and initial speed launch, and the integrated environment simulation component further enhances the expansion capability of the device in complex environment simulation.

Description

Technical Field

[0001] This invention relates to the field of fire testing technology, specifically to a test device for simulating the ignition of combustibles by high-temperature molten beads. Background Technology

[0002] Electrical fires consistently account for approximately 30% of all fires, making them a key area for prevention. Faulty arc discharges (with a center temperature reaching 6500-12000K) produce high-temperature molten beads. The ignition process of these molten beads is complex and highly dangerous, making them a significant cause of electrical fires.

[0003] However, existing experiments on high-temperature particle ignition have significant limitations: they typically use fixed-size particles that fall in a simple manner, making it impossible to flexibly switch between two typical ignition scenarios—free fall without initial velocity and impact with initial velocity—on a single platform. This makes it difficult to simulate the diversity of molten beads in terms of temperature, velocity, and attitude in real-world faults. Furthermore, there is a lack of precise coordination and control of environmental factors (wind speed, temperature, humidity) on multiple boundary conditions such as the state of combustibles. The low degree of automation in each experimental stage (heating, release, data acquisition) leads to poor repeatability, insufficient parameter control precision, and difficulty in simultaneously monitoring the dynamic heat transfer of particles and the response process of combustibles.

[0004] It is evident that existing technologies are insufficient to systematically reveal the ignition mechanism of high-temperature molten beads, thus hindering the precise prevention and control of electrical fires at their source. Therefore, researching an ignition process reproduction experimental device capable of simulating real-world conditions and achieving precise control and synchronous monitoring of multiple parameters is of urgent and significant scientific and engineering value for a deeper understanding of fire mechanisms and the improvement of early warning and prevention capabilities. Summary of the Invention

[0005] To address the existing technical problems, this invention provides a simulated high-temperature molten bead ignition test device for combustibles, which offers convenient switching, precise control, and full-process test support for heating, releasing, controlling, and monitoring molten beads. The aim is to solve the problems of traditional molten bead combustion or impact test devices, such as limited functionality, inability to flexibly switch between free fall without initial velocity and launch with initial velocity, and insufficient integrated control and real-time monitoring of key parameters such as heating temperature, wind speed during descent, particle velocity, and changes in fuel bed weight.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A test device for simulating the ignition of combustibles by high-temperature molten beads includes a control cabinet, a heating furnace, and an environmental simulation component. The environmental simulation component includes an environmental simulation chamber, which is equipped with a speed-regulating fan, an ultrasonic humidifier, a heat radiation plate, and a lifting platform. An adjustable-angle fuel bed is connected to the upper end of the lifting platform, and a weighing sensor is installed at the bottom of the adjustable-angle fuel bed. The speed-regulating fan, ultrasonic humidifier, heat radiation plate, and weighing sensor are all electrically connected to the control cabinet. A robotic arm is connected to the upper end of the control cabinet, and a crucible is connected to the front end of the robotic arm. The robotic arm is capable of moving the crucible into the heating furnace and the environmental simulation chamber. When conducting an initial velocity ignition test, the environmental simulation chamber is equipped with an initial velocity test mechanism, which includes a mounting bracket. The mounting bracket is equipped with a programmable transmitter component and a photoelectric speed measuring component. The programmable transmitter component is used to adjust the emission speed of the molten bead, and the photoelectric speed measuring component is used to measure the emission speed of the molten bead. Both the programmable transmitter component and the photoelectric speed measuring component are electrically connected to the control cabinet.

[0007] In the above technical solution, during the initial velocity ignition test, the environmental simulation component is set and activated via the control cabinet to ensure that the environmental parameters (thermal radiation intensity, air humidity, wind speed) within the environmental simulation chamber reach preset values ​​and remain stable. The prepared fuel is then spread evenly on an adjustable-angle fuel bed, and the lifting platform is adjusted to a predetermined height. Subsequently, the target heating temperature of the heating furnace is set via the control cabinet, and molten beads are placed in a crucible at the front end of the robotic arm and fed into the heating furnace by the robotic arm. Once the molten bead temperature reaches the preset value, the control cabinet drives the robotic arm to carry the high-temperature molten beads into the environmental simulation chamber and directly and precisely releases the molten beads onto the surface of the adjustable-angle fuel bed under specific composite environmental conditions. During a launch impact ignition test with initial velocity, the environmental simulation component is set and activated via the control cabinet to ensure that the environmental parameters (thermal radiation intensity, air humidity, wind speed) within the simulation chamber reach preset values ​​and remain stable. The prepared fuel is then spread evenly on an adjustable-angle fuel bed, and the lifting platform is adjusted to a predetermined height. Subsequently, the target heating temperature of the furnace is set via the control cabinet. Molten beads are placed in a crucible at the front of the robotic arm and fed into the furnace for heating. Once the molten bead temperature reaches the preset value, the control cabinet drives the robotic arm to carry the high-temperature molten bead into the environmental simulation chamber. The required launch velocity is set via the control cabinet, and the molten bead is accelerated and launched by the programmable launch component, landing on the adjustable-angle fuel bed. The instantaneous velocity of the molten bead as it passes the photoelectric velocity measuring component is calculated. From the moment the molten pellets are released, the control cabinet simultaneously records the weighing sensor readings, wind speed data, and the historical temperature curve of the molten pellets. Experimenters record the rolling trajectory of the molten pellets, their contact with the fuel, the ignition time of smoldering or flame formation, and the flame spread process through an observation window. After the experiment, the system records the final mass loss of the fuel. By changing variables such as the material, size, temperature, fuel type, fuel bed characteristics, wind speed, and fuel bed tilt angle of the molten pellets, and repeating the above process, the influence of each parameter on the ignition probability and fire behavior of the flying spark particles can be systematically studied. The entire process achieves fully automated and high-precision control from heating, precise delivery, environmental simulation to multi-parameter synchronous monitoring.

[0008] Preferably, the robotic arm includes a mounting base with a lead screw arranged horizontally on the mounting base. The lead screw is connected to the output end of a first motor. A second motor is connected to the lead screw slider. The output shaft of the second motor is connected to the mounting arm. The front end of the mounting arm is provided with a mounting structure for mounting the crucible. An S-type thermocouple is provided at the bottom of the crucible. The S-type thermocouple is electrically connected to a temperature transmitter, which is electrically connected to the control cabinet.

[0009] In this scheme, the first motor drives the lead screw to rotate, and the lead screw slider drives the second motor to move, which in turn drives the mounting arm and the crucible at its front end to move, sending the crucible into the heating furnace for heating. When the S-type thermocouple detects that the crucible has been heated to the specified temperature, the first motor drives the lead screw to move the crucible into the environmental simulation chamber. Then, the second motor moves to drive the mounting arm and the crucible to rotate, releasing the molten beads in the crucible onto the adjustable angle fuel bed.

[0010] Preferably, a heat insulation baffle is provided on the mounting arm at the rear side of the mounting structure, and a first opening is provided on the side of the heating furnace facing the robotic arm. The mounting structure and the crucible enter the heating furnace through the first opening. The diameter of the heat insulation baffle is larger than the diameter of the first opening, and the diameter of the mounting structure is smaller than the diameter of the first opening.

[0011] Once the crucible enters the heating furnace, the heat insulation baffle is positioned at the first opening of the furnace to prevent heat leakage and ensure a stable heating environment and high-temperature safety.

[0012] Preferably, the mounting structure has an opening groove with a raised edge near its upper end. The crucible is embedded in the opening groove, and the upper end of the crucible can abut against the raised edge for restraint. After the crucible is mounted on the mounting structure, the upper end of the crucible can abut against the raised edge of the opening groove to restrain the crucible and prevent it from falling off the mounting structure during the rotation of the mounting arm.

[0013] Preferably, a first position sensor and a second position sensor are provided on the mounting base along the moving direction of the second motor, and the first position sensor and the second position sensor are electrically connected to the first motor respectively. When the lead screw slider touches the first position sensor, it indicates that the lead screw mechanism has retracted to its limit position; when the lead screw slider touches the second position sensor, it indicates that the crucible has entered the center position of the heating chamber of the heating furnace.

[0014] Preferably, the programmable launch assembly includes a launch bracket mounted on the mounting bracket. A launch tube is horizontally mounted on the launch bracket, and a receiving cup is located at the upper end of the launch tube, near the inlet of the launch tube. The molten bead can fall from the receiving cup into the launch tube. Multiple sets of accelerating coils are fitted onto the launch tube, evenly distributed along the axial direction of the launch tube. Each accelerating coil is electrically connected to a coil controller. The control cabinet sets the required launch speed and sends the speed parameters to the coil controller. The coil controller sets the operating voltage and conduction sequence of the accelerating coils based on the relationship between speed and coil voltage. After the molten bead is heated, it is fed into the receiving cup by a robotic arm. The molten bead slides into the launch tube, and the coil controller sequentially energizes the accelerating coils. The alternating magnetic field generated by the energized accelerating coils produces a Lorentz force. The accelerating coils are energized sequentially, thereby accelerating the molten bead and launching it. Multiple accelerating coils are coaxially arranged along the axial direction of the launch tube and fixed outside the launch tube, arranged at equal intervals or at specific spacings. As the voltage of the accelerating coil changes and the conduction sequence changes, the molten beads are accelerated in turn, eventually reaching the preset initial velocity and leaving the emitter tube.

[0015] Preferably, the photoelectric speed measuring component is located at the outlet of the transmitting tube. The photoelectric speed measuring component includes a speed measuring housing on the transmitting bracket. The speed measuring housing contains a speed measuring tube and a signal processing module. The speed measuring tube contains a start light curtain and a stop light curtain. The start light curtain and the stop light curtain are electrically connected to the signal processing module. The speed measuring tube is concentrically arranged with the transmitting tube.

[0016] The molten bead first passes through the start light curtain, generating an obstruction, and the signal processing module obtains a start signal. The molten bead then passes through the stop light curtain, generating an obstruction, and obtains a stop signal. Based on the time difference between the two obstructions and the length between the two light curtains, the signal processing module can calculate the instantaneous speed of the molten bead as it passes through the speed measuring device.

[0017] Preferably, the adjustable angle fuel bed includes a frame mounted on the lifting platform, with a bed rotatably connected to the upper end of the frame. An angle sensor is mounted on the bed and electrically connected to the control cabinet. The weighing sensor is located at the bottom of the frame.

[0018] Preferably, the environmental simulation chamber is provided with a second opening, which is concentrically arranged with the first opening, and the mounting structure and the crucible can enter and exit the environmental simulation chamber through the second opening.

[0019] Preferably, the control cabinet is equipped with a control cabinet power switch, indicator lights and alarms, and a touch screen display.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention enables flexible and rapid switching between two test modes: free fall without initial velocity and launch with initial velocity. A single core device can meet multiple test requirements, avoiding the need to repeatedly build an entire system for a single function, thus improving equipment utilization and test flexibility. The integrated environmental simulation chamber, as an independent and accessible unit, further enhances the device's scalability in simulating complex environments. 2. This invention can centrally control the robotic arm's movements, heating temperature, and fan speed through a control cabinet, and monitor and display various key parameters such as molten bead temperature curve, wind speed, particle velocity, and fuel bed weight in real time. This design realizes integrated, visualized, and automated management of the entire experimental process of "heating-release-environmental control (wind speed)-process monitoring (speed, weight)", which can comprehensively and accurately acquire experimental data and provide strong technical support for in-depth research on the combustion or impact behavior of molten beads under different conditions. 3. By introducing an independent environmental simulation chamber, this invention enables precise, independent, and coordinated control of wind speed, ambient humidity, and external thermal radiation within a closed space. This allows the experiment to systematically study the impact of different environmental conditions (such as crosswinds under different humidity levels) on the ignition process of thermal particles, thereby more realistically simulating complex and ever-changing actual fire scenarios and providing a key technical means for analyzing the role of environmental factors in the ignition of flying sparks.

[0021] 4. This invention optimizes the realism of the simulation test. When the initial velocity function is not performed, the fuel bed height is adjustable, and a rolling ramp at a specific angle can be installed at the fuel bed inlet to simulate the actual situation of molten beads rolling down the ramp and then contacting the fuel. When the initial velocity launch test is performed, the launch speed of the molten beads is adjustable to simulate the impact scenario of flying fire at different speeds, thereby enhancing the test's ability to simulate complex real fire scenes. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention during the initial velocity test; Figure 2 This is a schematic diagram of the structure of the present invention during the initial velocity test; Figure 3 for Figure 2 A schematic diagram of the structure of the programmable transmitter component; Figure 4 for Figure 3 A schematic diagram of the launch principle; Figure 5 for Figure 2 A schematic diagram of the photoelectric speed measuring component in the image; Figure 6 for Figure 5 Side view; Figure 7 This is a schematic diagram of the environment simulation component in this invention; Figure 8 This is a schematic diagram of the structure of the robotic arm of the present invention; Figure 9 for Figure 8 A magnified view of a portion of the image; Figure 10 This is a schematic diagram of the heat insulation baffle abutting against the first opening after the crucible of the present invention is inserted into the heating furnace; Figure 11 This is a schematic diagram of the adjustable angle fuel bed in this invention; Figure 12 for Figure 11 A schematic diagram of the structure of the bed after it has been rotated. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0024] In the description of this application, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "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 application 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 application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0027] Example 1 As attached Figure 1 Appendix Figure 7 -Appendix Figure 12 The illustrated device is a test apparatus for simulating the ignition of combustibles by molten beads at high temperatures. This embodiment is mainly for free-fall or rolling ignition tests without initial velocity. It includes a control cabinet 1, a heating furnace 6, and an environmental simulation component. The environmental simulation component is located between the control cabinet 1 and the heating furnace 6. The environmental simulation component includes an environmental simulation chamber 13, which is equipped with a speed-regulating fan 7, an ultrasonic humidifier 16, a heat radiation plate 15, and a lifting platform 8. The upper end of the lifting platform 8 is connected to an adjustable-angle fuel bed 9, and the bottom of the adjustable-angle fuel bed 9 is equipped with a weighing sensor. The sensor 93 is used in the experiment. A rolling ramp is installed at the inlet of the adjustable angle fuel bed 9 to simulate the scenario of metal rolling freely down the ramp. The variable speed fan 7, ultrasonic humidifier 16, heat radiation plate 15, and weighing sensor 93 are all electrically connected to the control cabinet 1. The upper end of the control cabinet 1 is connected to a robotic arm 5. The front end of the robotic arm 5 is connected to a crucible 54, which is used to hold molten beads. The crucible 54 is made of corundum. The robotic arm 5 can move the crucible 54 into the heating furnace 6 and the environmental simulation chamber 13. In this embodiment, the heating furnace 6 can preferably be a muffle furnace.

[0028] The variable-speed fan 7 is used to adjust the ambient wind speed, and the ultrasonic humidifier 16, model HUM-3S from DanVex, is used to provide the required humidity. The heat radiation plate 15, model HTL-300EX, provides the required heat, including a graphite plate, and mainly provides heat through thermal radiation. The combination of these three components enables high-precision simulation and synchronous monitoring of the entire ignition process of flying spark particles under a multi-physics field coupling environment of wind speed, humidity, and thermal radiation.

[0029] Control cabinet 1, as the core control unit, integrates a touchscreen industrial computer, a human-machine interface, signal acquisition circuits, motor drive circuits, power supply circuits, etc., which are existing technologies and will not be described in detail in this embodiment. The control cabinet 1 panel is equipped with a control cabinet power switch 2, indicator lights and alarms 3, and a touchscreen display 4. The integrated monitoring and control system communicates with control cabinet 1 through host computer software to remotely set test parameters, automatically control the process, and synchronously acquire, record, and display all sensor data.

[0030] refer to Figure 8 , Figure 9 , Figure 10 The robotic arm 5 includes a mounting base 50, on which a lead screw 56 is arranged horizontally. The lead screw 56 is connected to the output end of a first motor 51. A second motor 52 is connected to the lead screw slider of the lead screw 56. The output shaft of the second motor 52 is connected to a mounting arm 53, which is arranged horizontally. The front end of the mounting arm 53 is provided with a mounting structure 511 for mounting the crucible 54. The mounting structure 511 is made of high-temperature resistant material. An S-type thermocouple 59 is provided at the bottom of the crucible 54 to obtain a more accurate temperature of the molten bead. The S-type thermocouple 59 is electrically connected to a temperature transmitter 510, which is electrically connected to the control cabinet 1. The temperature transmitter 510 transmits the temperature signal of the crucible 54 to the control cabinet 1 for display and recording.

[0031] A heat insulation baffle 58 is provided on the mounting arm 53 at the rear side of the mounting structure 511. A first opening 601 is provided on the side of the heating furnace 6 facing the robotic arm 5. The mounting structure 511 and the crucible 54 enter the heating furnace 6 through this first opening 601. The diameter of the heat insulation baffle 58 is larger than the diameter of the first opening 601, and the diameter of the mounting structure 511 is smaller than the diameter of the first opening 601. The heat insulation baffle 58 on the mounting arm 53 acts like a plug, sealing the first opening 601 on the heating furnace 6 after it extends into the heating furnace 6, preventing heat loss from the heating chamber.

[0032] The environmental simulation chamber 13 is provided with a second opening 14, through which the mounting structure 511 and the crucible 54 can enter or exit the environmental simulation chamber 13. The second opening 14 and the first opening 601 are located on the same horizontal line. After the mounting arm 53 and its front end mounting structure 511 retract from the first opening 601 of the heating furnace 6, they can directly enter the environmental simulation chamber 13 through the second opening 14.

[0033] The mounting structure 511 is provided with an opening groove 512, and a protruding edge is provided near the upper end of the opening groove 512. The crucible 54 is embedded in the opening groove 512, and the upper end of the crucible 54 can be limited by abutting the protruding edge.

[0034] The mounting base 50 is equipped with a first position sensor 55 and a second position sensor 57 along the moving direction of the second motor 52. The first position sensor 55 and the second position sensor 57 are electrically connected to the first motor 51, respectively. When the second position sensor 57 is triggered, the mounting arm 53 extends into position, at which point the crucible 54 is located at the center of the heating chamber of the heating furnace 6. When the first position sensor 55 is triggered, the mounting arm 53 retracts to the corresponding position inside the environmental simulation chamber 13. At this time, the second motor 52 starts and drives the crucible 54 to rotate, and the molten beads inside the crucible 54 slide down to the adjustable angle fuel bed 9.

[0035] The control cabinet 1 drives the robotic arm 5 to perform extension and rotation actions through the built-in motor controller. Specifically, the first motor 51 drives the lead screw 56 to rotate, and the lead screw slider drives the second motor 52 to move, which in turn drives the mounting arm 53 and the crucible 54 at its front end to move, sending the crucible 54 into the heating furnace 6 for heating. When the S-type thermocouple 59 detects that the crucible 54 has been heated to the specified temperature, the first motor 51 drives the lead screw 56 to move the crucible 54 back into the environmental simulation chamber 13. Then, the second motor 52 drives the mounting arm 53 to rotate, releasing the molten beads in the crucible 54. During the rotation of the mounting arm 53, since the upper end of the crucible 54 is abutting against the protruding edge on the opening slot 512, it is ensured that the crucible 54 is stably fixed to the mounting structure 511 during the tipping and pouring process, and is not easy to fall off.

[0036] refer to Figure 11 and Figure 12 The adjustable angle fuel bed 9 includes a frame 91 mounted on the lifting platform 8. A bed 92 is rotatably connected to the upper end of the frame 91. The rotation of the bed 92 can be achieved using existing technology, such as a rotating shaft connection. An angle sensor is mounted on the bed 92 to monitor the rotation angle of the bed 92. The angle sensor is electrically connected to the control cabinet 1. The weighing sensor 93 is located at the bottom of the frame 91.

[0037] The lifting platform 8 can be adjusted in height between 100mm and 200mm, allowing for synchronous adjustment of the height of the adjustable angle fuel bed 9. A rolling ramp at a specific angle can be added to the inlet of the adjustable angle fuel bed 92 to simulate the scenario of molten beads rolling down the ramp. An air speed sensor is installed inside the environmental simulation chamber 13, mounted above the adjustable angle fuel bed 9. The speed-regulating fan 7 can form a closed-loop control with the air speed sensor, allowing the required air speed to be set and maintained stably on the control cabinet 1. A weighing sensor 93 can continuously and accurately monitor changes in fuel mass during the test. A high-speed camera is installed inside the environmental simulation chamber 13 to capture images of the ignition test process.

[0038] The usage process of the experimental apparatus in this embodiment is as follows: First, the prepared fuel (such as pine needles, wood chips, etc.) is spread evenly on the bed 92 of the adjustable angle fuel bed 9, and the lifting platform 8 is adjusted to the predetermined height. A rolling ramp is installed at the entrance of the bed 92 of the adjustable angle fuel bed 9. The target wind speed (such as 1.5 m / s) is set through the control cabinet 1 panel, and the speed-regulating fan 7 is started. After the wind speed sensor feedback value stabilizes, the adjustable angle fuel bed 9 is weighed and tare. Then, the heating and delivery operation is carried out. The target heating temperature of the heating furnace 6 (e.g., 800℃) is set through the control cabinet 1. A molten bead (e.g., a steel ball) of predetermined material and size is placed into the crucible 54 and the heating is started. The temperature of the molten bead is monitored by the S-type thermocouple 59 integrated at the bottom of the crucible 54. After it reaches the preset temperature and stabilizes, the control cabinet 1 drives the robotic arm 5 to extend and move the crucible 54 to a predetermined position above the adjustable angle fuel bed 9. Then, the mounting arm 53 rotates to tilt the crucible 54. The molten bead then rolls down the rolling ramp without initial velocity onto the surface of the bed body 92 of the adjustable angle fuel bed 9. Finally, data acquisition and process observation were conducted. From the moment the molten beads were released, control cabinet 1 simultaneously recorded the high-speed camera's images, weighing sensor readings, wind speed data, and the historical temperature curve of the molten beads. Experimenters recorded the particle's rolling trajectory, contact with the fuel, smoldering or ignition time with flames, and flame spread process through the observation window or high-speed video feed. After the experiment, the system recorded the final mass loss of the fuel. By changing variables such as the material, size, temperature, fuel type, bed characteristics, wind speed, and slope angle of the molten beads, and repeating the above process, the influence of various parameters on the ignition probability and fire behavior of the flying spark particles could be systematically studied. The entire process achieved fully automated and high-precision control from heating, precise delivery, environmental simulation to multi-parameter synchronous monitoring.

[0039] Example 2 When a launch impact ignition test with initial velocity is required, the structure in Example 2 shall be used.

[0040] refer to Figures 2-12 The illustrated test device for simulating the ignition of combustibles by molten beads at high temperatures differs from Embodiment 1 in that, when conducting a launch impact ignition test with initial velocity, the environmental simulation chamber 13 is further equipped with an initial velocity test mechanism. The initial velocity test mechanism includes a mounting bracket 11, on which a programmable launch component 12 and a photoelectric velocity measuring component 10 are mounted. The programmable launch component 12 is used to adjust the launch speed of the molten beads, and the photoelectric velocity measuring component 10 is used to measure the launch speed of the molten beads. Both the programmable launch component 12 and the photoelectric velocity measuring component 10 are electrically connected to the control cabinet 1.

[0041] refer to Figure 3 and Figure 4The programmable transmitter assembly 12 includes a transmitter bracket 126 mounted on the mounting bracket 11. A transmitter tube 121 is horizontally mounted on the transmitter bracket 126. A receiver cup 122 is located at the upper end of the transmitter tube 121, near the entrance of the transmitter tube 121. Molten beads 124 can fall from the receiver cup 122 into the transmitter tube 121. Multiple sets of accelerating coils 123 are wound around the transmitter tube 121, evenly distributed along the axial direction of the transmitter tube 121. Each accelerating coil 123 is electrically connected to a coil controller 125. The required emission speed is set by control software, and the speed parameter is sent to the coil controller 125 via an RS232 bus. The coil controller 125 sets the operating voltage and conduction sequence of the accelerating coils 123 based on the relationship between speed and coil voltage. After the molten bead is heated, it is sent into the receiving cup 122 by the robotic arm 5. The molten bead slides from the receiving cup 122 into the transmitting tube 121. The coil controller 125 energizes the acceleration coils 123 in sequence. The generated alternating magnetic field will produce Lorentz force. The acceleration coils 123 are energized one by one in sequence, and the molten bead is accelerated and launched. Multiple acceleration coils 123 are arranged at equal intervals or at specific intervals along the axis of the transmitting tube 121 outside the transmitting tube 121. With the change of coil voltage and the conduction sequence, the molten bead is accelerated in sequence and finally leaves the transmitting tube 121 after reaching the preset initial velocity.

[0042] The working principle of the multi-stage acceleration coils 123 of the programmable transmitter assembly 12 is as follows: When an acceleration coil 123 is energized, a magnetic field is formed around it. This magnetic field induces a current in the molten bead. The magnetic field of the induced current interacts with the magnetic field of the coil, generating a thrust or attraction force that accelerates the molten bead forward. To achieve continuous acceleration, multiple sets of acceleration coils are arranged along the axial direction of the transmitter tube 121 to accelerate the molten bead in multiple stages. Each acceleration coil 123 must be energized precisely when the molten bead reaches its center position, at which point the magnetic field strength is at its maximum. The coils must be de-energized immediately just before the molten bead flies away. The timing of the coils' "on" and "off" must be precisely synchronized with the flight position of the molten bead, i.e., they are switched on and off sequentially to generate a continuous forward thrust. Different energizing voltages produce different magnetic forces, resulting in different speeds of the molten bead. According to the required launch speed, the control software sends the speed parameters to the coil controller 125 of the launching device via the RS232 bus. The coil controller 125 converts the speed into the corresponding voltage value, energizing time and energizing sequence, controls the working state of the acceleration coil 123, and generates different thrusts, so that the molten beads reach the preset launch speed.

[0043] refer to Figure 5 and Figure 6The photoelectric speed measuring component 10 is located at the outlet of the transmitting tube 121. The photoelectric speed measuring component 10 includes a speed measuring housing 101 mounted on the transmitting bracket 126. The speed measuring housing 101 contains a speed measuring tube 104 and a signal processing module (not shown in the figure). The speed measuring tube 104 contains a start light curtain 102 and a stop light curtain 103, which are electrically connected to the signal processing module. The speed measuring tube 104 is concentrically arranged with the transmitting tube 121. When the molten bead passes through the speed measuring tube 104, it first experiences a blockage at the start light curtain 102, generating a start signal from the signal processing module. When the molten bead passes through the stop light curtain 103, it experiences another blockage, generating a stop signal. Based on the time difference between the two blockage signals and the length between the start light curtain 102 and the stop light curtain 103, the signal processing module can calculate the instantaneous velocity of the molten bead as it passes through the photoelectric speed measuring component 10. The principle of light curtain speed measurement is existing technology and will not be described in detail here.

[0044] The remaining structure of Embodiment 2 is the same as that of Embodiment 1, and will not be described in further detail.

[0045] The usage process of the experimental apparatus in this embodiment is as follows: First, the environmental simulation component is set and activated through control cabinet 1 to ensure that the environmental parameters (thermal radiation intensity, air humidity, wind speed) inside the environmental simulation chamber 13 reach preset values ​​and remain stable. The prepared fuel is spread evenly on the adjustable angle fuel bed 9. Then, the target heating temperature of the heating furnace 6 is set through control cabinet 1. Molten beads are placed into the crucible 54 at the front end of the robotic arm 5 and sent into the heating furnace 6 for heating. After the temperature of the molten beads reaches the preset value, the robotic arm 5 carries the high-temperature molten beads into the interior of the environmental simulation chamber 13. Then, the molten beads are accelerated and their speed is measured. The required launch speed is set through the control cabinet 1, and the speed parameters are sent to the coil controller 125 via the RS232 bus. The coil controller 125 sets the working voltage and conduction sequence of the acceleration coil 123. After the molten beads are heated, they are sent into the receiving cup 122 by the robotic arm 5. The molten beads slide into the launch tube 121. The coil controller 125 energizes the acceleration coils 123 in sequence. The generated alternating magnetic field will generate a Lorentz force acting on the molten beads. The acceleration coils 123 are energized one by one in sequence. With the change of coil voltage and conduction sequence, the molten beads are accelerated in sequence. Finally, after reaching the preset initial speed, they leave the launch tube 121. When the molten beads leave the launch tube 121 and pass through the speed measuring tube 104, the photoelectric speed measuring component 10 will calculate the instantaneous speed of the molten beads after passing through the speed measuring device. After passing through the speed measuring tube 104, the molten beads are released onto the surface of the bed body 92 of the adjustable angle fuel bed 9 in a mode with initial speed. Finally, data acquisition and process observation are carried out. From the moment the molten beads are released, control cabinet 1 synchronously records the high-speed camera's images, weighing sensor readings, wind speed data, and the temperature curve of the molten beads through the integrated monitoring and control system. The test personnel record the rolling trajectory of the particles, the contact with the fuel, the ignition time of smoldering or flames, and the flame spread process through the observation window or high-speed image. After the test, the system records the final mass loss of the fuel. By changing the material, size, temperature, fuel type, wind speed, and slope angle of the molten beads, the above process can be repeated to systematically study the influence of each parameter on the ignition probability and fire behavior of the flying spark particles. At the same time, high-precision simulation and synchronous monitoring of the entire ignition process of flying spark particles are realized in the multi-physics field coupling environment of "wind speed-humidity-thermal radiation".

[0046] This invention has the following advantages: 1. Compared with existing single-function thermal particle ignition test devices, this invention achieves a significant breakthrough in the diversity and integration of test modes. By sharing a core control and heating module, and combining it with quickly replaceable modules with and without initial velocity, this invention can flexibly and efficiently simulate two typical flying spark particle ignition scenarios: "free fall" and "launch impact." It achieves high-precision simulation and reproduction of the flying spark ignition process in multiple modes and in an integrated manner, ensuring the functional completeness and research efficiency of the test platform.

[0047] 2. Compared to existing simple devices with rudimentary control and reliance on manual operation, this invention represents a comprehensive innovation in the control and measurement of key variables during the experimental process. Through automated and precise delivery by a robotic arm, contact-type particle temperature measurement, closed-loop stable wind speed control, direct measurement of launch velocity, and real-time monitoring of fuel bed quality, this invention achieves independent and precise control and synchronous high-dimensional data acquisition of multiple variables such as particle temperature, release state, and ambient wind speed, elevating the fly-fire ignition experiment from qualitative observation to a quantitative and repeatable scientific research level.

[0048] 3. This invention uses a retractable and rotatable robotic arm integrated with a crucible for contact temperature measurement, realizing full automation and precision in the automatic grabbing, transfer, and release of molten beads from the heating furnace with or without initial velocity or adjustable initial velocity. This completely eliminates the random errors caused by manual operation, ensures the consistency of initial conditions for each experiment, and lays a solid foundation for the reliability of research results.

[0049] 4. This invention integrates a weighing sensor, a wind speed sensor, and a speed measurement component, and forms a closed-loop or high-precision measurement circuit with the control circuit of the control cabinet. It can monitor and record the mass loss of the fuel bed, the wind speed in the test area, and the launch speed of the molten beads in real time, thereby enabling the simultaneous acquisition of multi-dimensional, time-series data on "particle state-environmental conditions-fuel response", providing key data support for in-depth analysis of ignition energy transfer and combustion dynamics.

[0050] 5. This invention has been meticulously optimized in terms of simulation realism. The height of the adjustable angle fuel bed without the initial velocity module is adjustable, and a rolling ramp at a specific angle can be added to simulate the actual situation of molten beads rolling down the ramp and then contacting the fuel. The launch speed with the initial velocity module is adjustable to simulate flying fire impact scenarios at different speeds, enhancing the test's ability to simulate complex real fire scenes.

[0051] 6. This invention achieves synchronous, precise and coordinated control of multiple environmental parameters such as wind speed, humidity and thermal radiation through an environmental simulation chamber. Compared with existing devices that can only simulate a single or a few environmental variables (such as controlling only wind speed), this design can realistically reproduce complex actual fire environments in a closed space, providing a key experimental means for systematically studying the ignition mechanism of flying spark particles under the coupled effects of multiple environmental factors.

[0052] The preferred embodiments of the present invention have been described above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A test device for simulating the ignition of combustible materials by high-temperature molten beads, characterized in that: The system includes a control cabinet (1), a heating furnace (6), and an environmental simulation component. The environmental simulation component includes an environmental simulation chamber (13), which is equipped with a speed-regulating fan (7), an ultrasonic humidifier (16), a thermal radiation plate (15), and a lifting platform (8). The upper end of the lifting platform (8) is connected to an adjustable angle fuel bed (9), and the bottom of the adjustable angle fuel bed (9) is equipped with a weighing sensor (93). The speed-regulating fan (7), the ultrasonic humidifier (16), the thermal radiation plate (15), and the weighing sensor (93) are all electrically connected to the control cabinet (1). The upper end of the control cabinet (1) is connected to a robotic arm (5), and the front end of the robotic arm (5) is connected to a crucible (54). The robotic arm (5) can move the crucible (54) into the heating furnace (6) and the environmental simulation chamber (13). When conducting an initial velocity ignition test, the environmental simulation chamber (13) is also equipped with an initial velocity test mechanism. The initial velocity test mechanism includes a mounting bracket (11), on which a programmable transmitter component (12) and a photoelectric speed measuring component (10) are mounted. The programmable transmitter component (12) is used to adjust the emission speed of the molten bead, and the photoelectric speed measuring component (10) is used to measure the emission speed of the molten bead. Both the programmable transmitter component (12) and the photoelectric speed measuring component (10) are electrically connected to the control cabinet (1).

2. The test device for simulating the ignition of combustibles by high-temperature molten beads according to claim 1, characterized in that: The robotic arm (5) includes a mounting base (50) on which a lead screw (56) is arranged in a horizontal direction. The lead screw (56) is connected to the output end of a first motor (51). A second motor (52) is connected to the lead screw slider of the lead screw (56). The output shaft of the second motor (52) is connected to the mounting arm (53). The front end of the mounting arm (53) is provided with a mounting structure (511) for mounting the crucible (54). The bottom of the crucible (54) is provided with an S-type thermocouple (59). The S-type thermocouple (59) is electrically connected to a temperature transmitter (510). The temperature transmitter (510) is electrically connected to the control cabinet (1).

3. The test device for simulating the ignition of combustibles by high-temperature molten beads according to claim 2, characterized in that: A heat insulation baffle (58) is provided on the mounting arm (53) at the rear side of the mounting structure (511). A first opening (601) is provided on the side of the heating furnace (6) facing the robotic arm (5). The mounting structure (511) and the crucible (54) enter the heating furnace (6) through the first opening (601). The diameter of the heat insulation baffle (58) is larger than the diameter of the first opening (601), and the diameter of the mounting structure (511) is smaller than the diameter of the first opening (601).

4. The test device for simulating the ignition of combustibles by high-temperature molten beads according to claim 2, characterized in that: The mounting structure (511) is provided with an opening groove (512), and a protruding edge is provided near its upper end on the opening groove (512). The crucible (54) is embedded in the opening groove (512), and the upper end of the crucible (54) can be stopped by the protruding edge.

5. The test device for simulating the ignition of combustibles by high-temperature molten beads according to claim 2, characterized in that: A first position sensor (55) and a second position sensor (57) are provided on the mounting base (50) along the moving direction of the second motor (52). The first position sensor (55) and the second position sensor (57) are electrically connected to the first motor (51) respectively.

6. The test device for simulating the ignition of combustibles by high-temperature molten beads according to claim 1, characterized in that: The programmable transmitter assembly (12) includes a transmitter bracket (126) mounted on the mounting bracket (11). A transmitter tube (121) is mounted on the transmitter bracket (126) in a horizontal direction. A receiver cup (122) is mounted on the upper end of the transmitter tube (121). The receiver cup (122) is positioned close to the inlet of the transmitter tube (121). Molten beads can fall from the receiver cup (122) into the transmitter tube (121). Multiple sets of accelerating coils (123) are mounted on the transmitter tube (121). The multiple sets of accelerating coils (123) are evenly distributed along the axial direction of the transmitter tube (121). The accelerating coils (123) are electrically connected to the coil controller (125) respectively.

7. The test device for simulating the ignition of combustible materials by high-temperature molten beads according to claim 6, characterized in that: The photoelectric speed measuring component (10) is located at the outlet of the transmitting tube (121). The photoelectric speed measuring component (10) includes a speed measuring housing (101) on the transmitting bracket (126). The speed measuring housing (101) contains a speed measuring tube (104) and a signal processing module. The speed measuring tube (104) contains a start light curtain (102) and a stop light curtain (103). The start light curtain (102) and the stop light curtain (103) are electrically connected to the signal processing module. The speed measuring tube (104) and the transmitting tube (121) are concentrically arranged.

8. The test device for simulating the ignition of combustibles by high-temperature molten beads according to claim 1, characterized in that: The adjustable angle fuel bed (9) includes a frame (91) mounted on the lifting platform (8), a bed (92) rotatably connected to the upper end of the frame (91), an angle sensor mounted on the bed (92), the angle sensor being electrically connected to the control cabinet (1), and a weighing sensor (93) located at the bottom of the frame (91).

9. The test device for simulating the ignition of combustible materials by high-temperature molten beads according to claim 3, characterized in that: The environmental simulation chamber (13) is provided with a second opening (14), through which the mounting structure (511) and the crucible (54) can enter or exit the environmental simulation chamber (13).

10. The test device for simulating the ignition of combustibles by high-temperature molten beads according to claim 1, characterized in that: The control cabinet (1) is equipped with a control cabinet power switch (2), indicator lights and alarms (3) and a touch screen (4).

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