Experimental device for igniting flying fire particles

Abstract

The invention discloses an experimental device for igniting flying fire particles, which comprises a gas bottle, a gas burner, an image acquisition device and measuring equipment, and is characterized in that the image acquisition device comprises a thermal infrared imager and a digital camera, and the measuring equipment comprises a thermocouple, a pitot tube, a high-precision balance, a high-precision vernier caliper, a high-precision dynamometer and a drying box. According to the experimental device for igniting the flying fire particles, various data changes in the process that the flying fire particles are ignited can be detected in an all-around mode, and scientific research on forest fire disasters, fire disasters in junctions of forests and cities and towns and building fire disasters can be enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of fire experiments, in particular to an experimental device for igniting flying fire particles. Background Art

[0002] Flying fire is the phenomenon that hot combustible particles (flying fire particles) are transported to the front of the fire front (a place other than where the hot particles are generated) by the coupling or individual effects of environmental wind, fire plume and gravity, and ignite the combustibles on the ground to form new fire points when they fall to the ground, which can cause the fire to spread faster and faster. Due to the complexity of flying fire ignition, traditional experiments will simplify the ignition process, and there is an extreme lack of experimental equipment for the combustion of flying fire particles under forced convection. Summary of the invention

[0003] In order to make up for the deficiencies of the prior art, the embodiments of the present application provide an experimental device for igniting flying fire particles to solve the problems existing in the prior art.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] The invention discloses an experimental device for igniting flying fire particles, comprising a gas cylinder, a gas burner, an image acquisition device and a measuring device, wherein the image acquisition device comprises an infrared thermal imager and a digital camera, and the measuring device comprises a thermocouple, a pitot tube, a high-precision balance, a high-precision vernier caliper, a high-precision dynamometer and a drying box. The gas cylinder is connected to the gas burner through a gas pipe, the gas burner is covered with wire mesh inside, and the wire mesh carries glass beads for stabilizing the gas flow. The flying fire particles are fixed on one side of the gas burner near the center line of the flame by particle-fixing metal nails, and the thermocouple and the pitot tube are placed on the other side near the center line of the flame. The digital camera records the ignition delay time of the flying fire particles, the thermocouple measures the flame plume temperature during the ignition of the flying fire particles, the pitot tube measures the flame plume flow rate of the flying fire particles, the high-precision balance measures the mass of the flying fire particles, the high-precision vernier caliper measures the diameter and length changes of the flying fire particles, the infrared thermal imager measures the surface temperature of the flying fire particles, and the high-precision dynamometer detects the critical stress change of the material.

[0006] As a further technical solution of the present invention, a pressure gauge is installed on the air pipe.

[0007] As a further technical solution of the present invention, a flow controller is installed on the air pipe.

[0008] As a further technical solution of the present invention, the gas cylinder is a propane tank.

[0009] As a further technical solution of the present invention, the experimental process is as follows: a certain moment is selected during the ignition of the flying fire particles, the flying fire particles at this moment are quenched with water, and the flying fire particles are dried in a drying oven at 100-120°C for 24 hours; after being taken out from the drying oven, the mass of the flying fire particles is measured with a high-precision balance; the length and diameter of the flying fire particles are measured with a high-precision vernier caliper; the flying fire particles are placed horizontally, one end of the flying fire particles is fixed, and the other end of the flying fire particles is pulled vertically downward with a high-precision dynamometer to measure the force value when the flying fire particles are broken.

[0010] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0011] The experimental device for igniting flying fire particles of the present invention can comprehensively detect various data changes of flying fire particles during the ignition process, which is helpful to strengthen scientific research on forest fires, fires at the interface between forests and towns, and building fires. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a working schematic diagram of the present invention.

[0013] In the figure: 1-gas cylinder, 2-gas burner, 3-wire mesh, 4-glass beads, 5-flying fire particles, 6-metal nails for fixing particles, 7-Pitot tube and thermocouple, 8-flame, 9-infrared thermal imager, 10-digital camera, 11-propane, 12-press, 13-flow controller. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] like Figure 1 As shown, an experimental device for igniting flying fire particles is used to study the changes in the surface temperature of flying fire particles during the ignition process of flying fire particles, the ignition delay time of flying fire particles (the ignition delay time of flying fire particles is the shortest time from the initial state to the ignition of flying fire particles to the self-sustaining combustion of flying fire particles. Self-sustaining combustion of flying fire particles is defined as the flying fire particles being ignited in the flame, and after leaving the flame, the flying fire particles can still continue to burn on their own to the end), the changes in the diameter of flying fire particles during the ignition process of flying fire particles, the changes in the residual mass of flying fire particles during the ignition process, and the changes in the material strength of flying fire particles during the ignition process.

[0016] The initial diameter of the flying fire particles is 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, and the initial length is three times the initial diameter. Each size of flying fire particles is heated and ignited at a fixed position in the flame generated by the combustion of propane, and the flying fire particles are placed horizontally. The variables are: for different initial diameters of flying fire particles, the flame temperature and flame velocity (determined by the propane flow rate) at the fixed position of the flame that ignites the flying fire particles, and the length of time the flying fire particles are heated in the flame.

[0017] The device combines thermocouples, pitot tubes, infrared thermal imagers, digital cameras, high-precision balances, high-precision vernier calipers, high-precision dynamometers, drying ovens and other experimental instruments to measure important parameters such as the flame plume temperature (thermocouple), flame plume velocity (pitot tube), ignition delay time of flying fire particles (corresponding time recorded by digital cameras), mass of flying fire particles (high-precision balance) and changes in diameter and length of flying fire particles (high-precision vernier calipers), surface temperature of flying fire particles (infrared thermal imager) and changes in critical stress of materials (obtained by material mechanics related calculations after measurement with high-precision dynamometers). The device can adjust the power of the propane burner. Fix the flying fire particles on the particle fixing nails and use the flame of the propane heater to ignite the flying fire particles.

[0018] The gas burner controls the propane flow rate through a flow controller, and can use propane of different flow rates for combustion as needed.

[0019] The chicken wire is used to hold the large amount of small glass beads and also helps to get a steady flow of propane.

[0020] A large number of small glass beads are used to obtain a steady flow of propane.

[0021] The flying fire particles are fixed by the particle fixing metal nails and placed on the side close to the center line of the flame to be ignited by the flame.

[0022] Thermocouple and Pitot tube are placed on the other side near the center line of the flame to measure the flame temperature and flame velocity respectively.

[0023] Use a digital camera to capture the phenomenon of the flying fire particles being ignited.

[0024] Use an infrared thermal imager to obtain the real-time surface temperature of the flying fire particles during the ignition process.

[0025] During the ignition process of flying fire particles, a certain moment is selected, the flying fire particles at that moment are quenched with water, and then the flying fire particles are dried in a drying oven at 100-120°C for 24 hours; after being taken out from the drying oven, the mass of the flying fire particles is measured with a high-precision balance; the length and diameter of the flying fire particles are measured with a high-precision vernier caliper; the flying fire particles are placed horizontally, one end of the flying fire particles is firmly fixed, and the other end of the flying fire particles is pulled vertically downward with a high-precision force gauge to measure the force value when the flying fire particles are broken.

[0026] Function of drying box: used to dry flying fire particles.

[0027] Function of high-precision balance: Measure the mass of flying fire particles.

[0028] Function of high-precision vernier caliper: measure the length and diameter of flying fire particles.

[0029] Function of high-precision force gauge: to measure the force value when flying fire particles are broken.

[0030] Here’s how it works:

[0031] The gas burner controls the propane flow rate through a flow controller, and a certain flow rate of propane can be selected according to the needs to burn and produce flames. The wire mesh is used to carry a large number of small glass beads, and it also helps to obtain a stable propane flow. A large number of small glass beads are used to obtain a stable propane gas flow. The flying fire particles are fixed by the particle fixing metal nails and placed on one side close to the center line of the flame to be ignited by the flame. Thermocouples and pitot tubes are placed on the other side close to the center line of the flame to measure the flame temperature and flame flow rate respectively. Use a digital camera to capture the phenomenon of the flying fire particles being ignited. Use an infrared thermal imager to capture the real-time surface temperature of the flying fire particles during the process of the flying fire particles being ignited. During the ignition process of flying fire particles, a certain moment is selected, the flying fire particles at that moment are quenched with water, and then the flying fire particles are dried in a drying oven at 100-120°C for 24 hours; after being taken out from the drying oven, the mass of the flying fire particles is measured with a high-precision balance; the length and diameter of the flying fire particles are measured with a high-precision vernier caliper; the flying fire particles are placed horizontally, one end of the flying fire particles is firmly fixed, and the other end of the flying fire particles is pulled vertically downward with a high-precision force gauge to measure the force value when the flying fire particles are broken.

[0032] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0033] In addition, it should be understood that although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment have also been appropriately combined to form other implementation modes that are easy for those skilled in the art to understand.

Claims

1. An experimental device for igniting flying fire particles, characterized in that: It includes a gas cylinder, a gas burner, an image acquisition device and a measuring device. The image acquisition device includes an infrared thermal imager and a digital camera. The measuring equipment includes a thermocouple, a pitot tube, a high-precision balance, a high-precision vernier caliper, a high-precision dynamometer and a drying box. The gas cylinder is connected to the gas burner through a gas pipe. The gas burner is covered with wire mesh inside. The wire mesh carries glass beads for stabilizing the gas flow. The flying fire particles are fixed on one side of the gas burner near the center line of the flame by metal nails for fixing the particles. The thermocouple and the pitot tube are placed on the other side near the center line of the flame. The digital camera records the ignition delay time of the flying fire particles. The thermocouple measures the flame plume temperature during the ignition process of the flying fire particles. The pitot tube measures the flame plume flow rate of the flying fire particles. The high-precision balance measures the mass of the flying fire particles. The high-precision vernier caliper measures the diameter and length changes of the flying fire particles. The infrared thermal imager measures the surface temperature of the flying fire particles. The high-precision dynamometer detects the critical stress changes of the material.

2. An experimental device for igniting flying fire particles according to claim 1, characterized in that: A pressure gauge is installed on the air pipe.

3. An experimental device for igniting flying fire particles according to claim 2, characterized in that: A flow controller is installed on the air pipe.

4. The experimental device for igniting flying fire particles according to claim 2, characterized in that: The gas cylinder is a propane tank.

5. The experimental device for igniting flying fire particles according to claim 1, characterized in that: The experimental process is as follows: select a certain moment during the ignition process of the flying fire particles, quench the flying fire particles at that moment with water, and bake the flying fire particles in a drying oven at 100-120°C for 24 hours; take them out of the drying oven and then measure the mass of the flying fire particles with a high-precision balance; use a high-precision vernier caliper to measure the length and diameter of the flying fire particles; place the flying fire particles horizontally, fix one end of the flying fire particles, and use a high-precision dynamometer to pull the other end of the flying fire particles vertically downward to measure the force value when the flying fire particles are broken.

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