CN210863655U - An experimental device for solid fuel variable-angle fire spread under the action of ambient wind - Google Patents

Abstract

The utility model discloses a solid fuel variable-angle fire spread experimental device under the action of environmental wind, which comprises a variable-angle solid fuel experimental bench, an air supply system and a data acquisition and processing system. The variable-angle solid fuel test bench can change the size of the experimental material according to the experimental requirements. The side connection angle adjustment disk of the test bench can be rotated at any angle. Combined with the different placement methods of the test bench and the wind tunnel, it can simulate the environmental wind of different directions and sizes; The thermocouple frame on the back of the stage is a combined rectangular structure. With the movable thermocouple frame on the front, it can measure the temperature of any position of the experimental material. Combined with the heat flow measurement system and the camera system, the measurement of the relevant parameters of the experiment is completed. The utility model establishes a set of simulation experimental device for studying the fire spread of building materials under the action of coupled environmental wind and inclination angle, the air supply system is safe, convenient and accurate, and has a complete parameter measurement system, which can study the ignition of building materials under different environmental conditions. The complete process of spreading.

Description

An experimental device for solid fuel variable-angle fire spread under the action of ambient wind

technical field

The utility model relates to the technical field of fire safety, in particular to the design of a solid fuel variable angle fire spread experimental device under the action of environmental wind, which is used for solid fuel combustion and fire spread behavior under the forced convection action of different wind speeds and wind directions Research.

Background technique

With the development of modern buildings in the direction of large space and multi-functionality, the types and quantities of combustible materials used in buildings have gradually increased, which can easily induce fires and spread rapidly, posing a great threat to building safety. Combustion of building materials is a kind of solid fire spread. Due to its complex composition, it is difficult to control the fire spread trend after a fire. Therefore, the study of fire spread on solid surfaces has great practical significance for the prevention and control of building fires.

In practical fire scenarios, the ambient wind and the inclination angle of materials are important factors that affect the burning rate of solid fuel and the speed of fire spread. Under the action of ambient wind, the combustion surface of building materials is subjected to the coupling effect of buoyancy and forced convection, which makes the heat transfer of solid materials and the evacuation process of combustion products different from those without outside wind; and different inclination angles will make the flame and the material relative to each other. The position changes, thereby changing the heat transfer to the surface of the material.

Previous studies have discussed the effects of ambient wind and material inclination angle on the combustion characteristics and fire spread behavior of solid fuels. Influence of environmental wind: Loh et al. studied the effect of environmental wind on the fire spread behavior of horizontal thermally thick PMMA, and found that the environmental wind has a linear relationship with the fire spread speed; Zhao Luyao revealed that the width of thermally thick material under downwind conditions affects the flame. The influence mechanism of structure and fire spread rate, based on the modified Spalding number, established a fire spread rate model based on flame stagnation distance; Wu et al. studied the effect of wind speed on PMMA fire spread rate under the condition of countercurrent fire spread through experiments and numerical simulations It is found that the increase of the flow rate will lead to the delay of PMMA ignition and the decrease of the fire spread rate; Chao et al. studied the law of downstream fire spread under the coupling effect of the external air flow rate and oxygen concentration, and reflected the effect of air flow rate on the fire spread process through the flame length and flame temperature. Ajay V.Singh et al. studied the effect of ambient wind on the combustion rate of horizontal solid fuel combustion; Fang Jun et al. studied the evolution relationship between the ignition time and surface temperature rise of non-carbonized material PMMA with wind speed and external radiative heat flow . Influence of material inclination angle: Chen Xiao et al. studied the effect of material inclination angle on the burning rate and flame shape of the material; M.J. Gollner et al. studied the change law of the fire spread rate of PMMA under different inclination angles, and found that the fire spread rate of the material varies with the material. It increases with the increase of the inclination angle; H.Ohtani et al. studied the relationship between the combustion rate and the heat transfer coefficient of the material at different inclination angles; Nakamura et al. studied the pyrolysis ignition and fire of thermally thin PMMA at different inclination angles. During the propagation process, it was found that when the material angle was between -90° and 30°, the ignition time on the front side of the material increased with the increase of the angle.

Through the investigation and analysis of the existing technology, it can be seen that most of the predecessors' research on solid fuels focused on the condition of a single influencing factor. The characteristic parameters of material combustion under the coupling effect of the tilt angle are quite different from the actual fire scene. Moreover, the data measured by the existing experimental methods are relatively simple, and there is no relevant special experimental research system. Therefore, it is urgent to develop an experimental device for the fire spread characteristics of combustibles that can effectively control and simulate the solid fuel fire scene in the actual environment and can precisely measure the experimental parameters.

To this end, the utility model designs and develops a fire simulation experiment system for solid fuel combustion and spread, and realizes an experimental device that can simulate the combustion and spread of solid fuel under the coupling action of different environmental wind speeds, wind directions, material sizes and material inclination angles. , which provides a complete set of solutions for studying the evolution law of characteristic parameters such as temperature distribution, heat flow distribution and flame shape during solid fuel combustion.

Utility model content

The purpose of the utility model is to provide a solid fuel variable angle fire spread experimental device under the action of environmental wind, in order to fully study the combustion behavior and fire spread characteristics of solid fuel with different inclination angles by environmental wind under the experimental scale.

The utility model adopts the following technical solutions:

A solid fuel variable-angle fire spread experimental device under the action of environmental wind, the device comprises a variable-angle solid fuel experimental bench, an air supply system and a data acquisition and processing system; wherein:

The main body of the variable-angle solid fuel test bench includes: a bottom support frame, an angle adjustment device, a material support plate, a material support frame, a material fixing device, a flame extension plate and a measurement system. The bottom support frame, the flame extension plate and the material support frame are made of aluminum profiles; the angle adjustment device, the material support plate, and the material fixing strip are made of stainless steel.

The angle adjustment device is composed of an angle adjustment disc and an angle fixing bolt. The angle adjustment disc is connected with the bottom support frame by bolts, and the angle fixing bolts are connected with the material support frame. The material support frame is fixed at a specified angle through angle fixing bolts, and the angle adjustment range between the material support frame and the horizontal plane is 0 to 180 degrees.

The solid fuel is placed in the center of the material support plate and fixed by the material fixing strips on the left and right sides. Both sides of the material are sealed by material retaining strips.

The flame extension plate and the material support plate are connected by bolts, and the length can be extended or contracted according to the flame length in the experiment.

The data acquisition and processing system includes a temperature measurement system, a heat flow measurement system, an wind speed measurement system and a camera system, wherein: the temperature measurement system includes two parts, one part is a plurality of thermocouples arranged from top to bottom placed inside the solid fuel , used to measure the internal temperature distribution of the material, and the other part is the thermocouple on the 2-D guide rail on the fuel side. The position of the 2-D guide rail is controlled by the computer to measure the flame and gas temperature distribution above the material; the heat flow measurement system is included in the A plurality of top-to-bottom heat flow meters placed inside the solid fuel are used to measure the flame heat flow distribution received by the solid; the anemometer system includes vertically distributed anemometers placed between the variable-angle solid fuel test bench and the fan device; the camera system is to set up a high-speed camera on the side of the variable-angle solid fuel test bench for real-time monitoring of the spreading behavior of the solid fuel.

The air supply system includes a small wind tunnel arranged on one side of the test bench, and a multi-array steady flow pipe is fixed on the side of the fan to provide uniform air flow; the fan is provided with a speed regulating valve, and the wind speed is adjustable; the air supply system has four sides. It is surrounded by light-transmitting glass to form a one-way ventilation experimental environment, which can provide a uniform and stable ambient wind.

Wherein, the different components of the experimental platform are connected by bolts, and the components can be disassembled. In order to study the combustion characteristics of solid fuels of different sizes, a number of material support plates with different sizes and measurement positions were designed.

Wherein, the solid fuel is a combustible solid material, such as acrylic, wood material, building thermal insulation material XPS, plywood and the like.

The advantages of the present utility model compared with the existing ones are:

The utility model establishes for the first time a set of experimental devices for studying solid fuel fire spreading behavior and flame characteristic parameters under the action of coupled complex environmental wind and material inclination angle, the wind direction and wind speed can be adjusted, the system is safe, convenient and numerically accurate. The beneficial technical effect of the present utility model is embodied in the following aspects:

1. In terms of experimental materials, the present utility model studies the fire behavior of a variety of combustible solid materials, such as acrylic, wood materials, building insulation materials XPS, plywood, etc., can select the corresponding experimental material types and sizes according to the experimental purpose, for simulation. Fire spread behavior of materials in different environments (wind speed, angle).

2. In terms of the experimental bench, each component of the experimental bench is a detachable structure, and the material support plate can be replaced according to the experimental materials and measurement requirements. The inclination angle of the material is adjusted by the angle fixing rod, and the angle adjustment disc displays the inclination angle of the solid fuel, thereby simulating the fire scene of solid fuel burning at different angles.

3. In terms of environmental wind simulation, the centrifugal variable speed engine can provide stable and continuous environmental wind, and its wind speed fluctuation is less than 2%. The direction of the test bench can be placed according to the test requirements, so as to simulate different environmental wind speeds and directions, so as to truly Simulate the complete process of building materials from ignition to spread under the action of complex environmental wind, which can be used to study the influence mechanism of environmental wind on the fire spread behavior of building materials;

4. In terms of experimental parameter measurement, the thermocouples on the 2-D guide rail can be moved arbitrarily in the two-dimensional direction under the control of the computer, and the number of thermocouples can be set according to the requirements, and then the two-dimensional flame in the horizontal and vertical directions can be measured. In the temperature field, there is an array thermocouple frame on the back of the material, which can measure the internal temperature distribution of the material; a radiation and heat flow measurement device is installed inside the material, which is convenient to study the influence mechanism of different wind speeds and inclination angles on the spread of solid fuel fire.

Description of drawings

1 is a schematic diagram of the overall structure of a solid fuel variable-angle fire spread experimental device under the action of ambient wind of the present utility model; in the figure: 1. wind wall; 2. rectifier pipe; 3. wind speed measuring device; 4. high-speed camera;

Figure 2 is a schematic diagram of the frontal structure of the variable-angle solid fuel fire spread test bench; in the figure: 5. Flame extension plate; 6. Fixing bolts; 7.2-D rail crossbar; 8. Heat flow meter; .Material fixing strip; 11. Thermocouple; 12. Material support frame-horizontal frame; 13. Material support plate; 14. Material support frame-mullion; 15. Angle adjustment disc; 16. Angle fixing rod; 17. Bottom support bracket;

Figure 3 is a schematic diagram of the back structure of the variable-angle solid fuel fire spread test bench; in the figure: 8. Heat flow meter; 12. Material support frame-horizontal frame; 18. Thermocouple frame;

FIG. 4 is a schematic structural diagram of the material fixing strip 10;

5 is a schematic structural diagram of the thermocouple frame 18; in the figure: 11. thermocouple; 18. thermocouple frame; 19. ferrule screw;

Figure 6 is a schematic diagram of the structure of the 2-D guide rail: in the figure: 7.2-D guide rail crossbar; 9.2-D guide rail vertical rod; 11. Thermocouple.

Detailed ways

Below in conjunction with the accompanying drawings, the present utility model will be further described through embodiments.

Referring to FIG. 1 , in this embodiment, a solid fuel variable-angle fire spread experiment device under the action of environmental wind includes a variable-angle solid fuel fire spread test bench, an air supply system, and a data acquisition system. The entire experimental simulation device is placed as shown in the figure, from left to right are the air supply system, the wind speed measurement device 3, the high-speed camera 4 and the variable-angle solid fuel fire spread test bench. The high-speed camera 4 is placed on the left side of the experimental bench, and is used to record the shape of the flame and other experimental phenomena during the experiment. The air supply system includes a wind wall 1 and a rectifier tube 2. The wind wall 1 includes a total of four sides, which encloses the solid fuel fire spread test bench to form a one-way ventilation space. The material of the wind wall 1 is transparent glass.

Referring to FIG. 2 , the bottom support frame 17 of the material is a T-shaped aluminum alloy frame. The angle adjustment plate 15 and the bottom support frame 17 are fixed by bolts. The center of the angle adjustment disk 15 is located at the center of the vertical rod of the bottom support frame 17 , and the top of the angle adjustment disk 15 is flush with the top of the vertical rod of the bottom support frame 17 . The material support frame is composed of two material support frames-transverse frame 12 and two material support frames-mullion 14 connected by bolts. A bolt to connect. There is a half arched hollow on the angle adjustment disc 15, the angle fixing rod 16 is fixed on the side of the material support frame-mullion 14 through the half arched hollow of the angle adjustment disc 15, and the material support frame is fixed at a certain inclination angle by bolts Location. The material support plate 13 is placed on the material support frame, and the four corners are fixed to the material support frame by bolts. The flame extension plate 5 is connected to the material support plate 13 through the fixing bolts 6, and the length of the flame extension plate 5 can be extended or contracted according to the needs of the experiment. The 2-D rail is fixed to the right side of the material support plate 13 . Thermocouples are fixed on 2-D rails and their position is controlled by a computer. The heat flow meters 8 are arranged in the center of the material support plate 13, and are distributed at the same interval from top to bottom. The heat flow meter 8 is rotated from the back of the material support plate 13 to a predetermined distance from the back of the material support plate 13 to the front of the material support plate 13 through threaded holes, and is fixed by screws. The experimental material is placed in the center of the material support plate 13, and is fixed to the material support plate 13 through the material fixing strip 10 through bolts.

Referring to FIG. 3 , the thermocouple frames 18 are arranged on the back of the material support plate 13 from top to bottom at the same interval, and are fixed by bolts. The heat flow meter 8 is rotated from the back to the front of the material support plate 13 through threaded holes.

Referring to FIG. 4 , the cross-section of the material fixing strip 10 is L-shaped, wherein the thinner stainless steel strip is partially covered on the experimental material, and the thicker stainless steel strip is fixed to the material support plate 13 by bolts. The thickness of the material fixing strip 10 is adjusted according to the thickness of the material, and the side surfaces of the material are closed.

Referring to FIG. 5 , the ferrule screw 19 is fixed on the thermocouple frame 18 by threads, the thermocouple 11 passes through the middle of the ferrule screw 19 , and the fixed position is adjusted by the ferrule screw.

Referring to FIG. 6 , the 2-D guide rail is composed of a 2-D guide rail vertical rod 9 and a 2-D guide rail cross rod 7 . The 2-D guide rail vertical rod 9 is connected with the 2-D guide rail cross rod 7 through the rail of the cross rod, and the thermocouple 11 is fixed on the 2-D guide rail vertical rod 9 . Through the computer, the 2-D guide rail vertical rod 9 can be controlled to move in the horizontal direction along the 2-D guide rail horizontal rod 7, and the thermocouple 11 can be controlled to move up and down along the 2-D guide rail vertical rod.

Experiment 1: Study the influence mechanism of complex environmental wind on the three-dimensional fire spread and flame characteristic parameters of high-rise buildings. First, rotate the test bench to the specified inclination angle, and arrange the temperature measurement system and heat flow measurement system on the front and back of the test bench to ensure that the 2-D guide rail, heat flow meter and thermocouple operate normally. Fix the experimental material at the center of the experimental bench, the heat flow meter and the thermocouple on the back of the experimental bench pass through the preset holes on the experimental material, and the material fixing strip wraps the two sides of the experimental material and fixes it in the designated position. Adjust the camera position and determine the shooting ratio. Turn on the fan, gradually adjust to the specified frequency, and determine the wind direction through the wind direction adjustment device. When the experiment is ready, evenly ignite the bottom of the material with a gas ignition source. Heat flow and temperature data are collected at the same time as ignition, and high-speed cameras record flame spread and evolution. By adjusting the fan frequency and wind direction control device with the rotation of the device, it is possible to study the three-dimensional fire spread of high-rise building material fires under the action of environmental winds with different wind directions and wind speeds. Experiments under different working conditions (the inclination angle of the experimental bench, the ambient wind direction, and the wind speed) need to wait for the material of the experimental bench to cool, and then repeat the preparation steps.

Experiment 2: Study the influence mechanism of ambient wind on the extinguishing of fire-fighting materials in buildings. First, arrange and debug the experimental instrument as described in Experiment 1. When the experiment is ready, evenly ignite the bottom of the material with a gas ignition source. Heat flow and temperature data are collected at the same time as ignition, and high-speed cameras record the spread and evolution of the flame. By adjusting the fan frequency and coordinating the placement angle of the device, it is possible to study the experiment that the fire of high-rise building materials changes from spreading to extinguishing under the action of environmental wind of different wind directions and wind speeds. Gradually increase the experimental wind speed until the material goes out. For multiple sets of experiments (the inclination angle of the experimental bench, the ambient wind direction, and the wind speed), it is necessary to wait for the material to cool, and then repeat the preparation steps.

Claims (3)

1. The utility model provides a solid fuel becomes angle conflagration and spreads experimental apparatus under environment wind effect which characterized in that: the device comprises a variable-angle solid fuel experiment table, an air supply system and a data acquisition and processing system; wherein:

the main body of the variable-angle solid fuel experiment table comprises: the device comprises a bottom support frame, an angle adjusting device, a material support plate, a material support frame, a material fixing device, a flame extension plate and a measuring system, wherein the bottom support frame and the material support frame are made of aluminum profiles; the angle adjusting device, the material supporting plate and the material fixing device are made of stainless steel;

the angle adjusting device is composed of an angle adjusting disc and an angle fixing bolt, the angle adjusting disc is connected with the bottom supporting frame through the bolt, the angle fixing bolt is connected with the material supporting frame, the material supporting frame is fixed at a specified angle through the angle fixing bolt, and the angle adjusting range of the material supporting frame and the horizontal plane is 0-180 degrees;

the solid fuel is placed in the center of the material supporting plate and is fixed by the material fixing strips at the left side and the right side, and the two side edges of the material are sealed by the material fixing strips;

the flame extension plate is connected with the material support plate, and the length of the flame extension plate can be extended or contracted according to the length of flame in an experiment;

the data acquisition and processing system comprises a temperature measuring system, a heat flow measuring system, a wind speed measuring system and a camera system, wherein: the temperature measuring system comprises a plurality of thermocouples which are arranged inside the solid fuel from top to bottom and are used for measuring the temperature distribution inside the material, and thermocouples arranged on a 2-D guide rail on one side of the fuel, wherein the 2-D guide rail is controlled by a computer to measure the temperature distribution of flame and air above the material; the heat flow measurement system comprises a plurality of top-to-bottom heat flow meters positioned inside the solid fuel for measuring the flame heat flow profile received by the solids; the wind speed measuring system is characterized in that a bundle of wind speed measuring points are arranged between the variable-angle solid fuel experiment table and the fan; one side of the camera system, which is actually a variable-angle solid fuel experiment table, is provided with a high-speed camera for recording the fire behavior of the solid fuel in real time;

the air supply system comprises a small wind tunnel arranged on one side of the test bed, and a multi-array flow stabilizing pipe is fixed on one side of the fan and used for providing uniform wind flow; the fan is provided with a speed regulating valve, and the wind speed is adjustable; the air supply system is surrounded by the light-permeable glass on four sides, so that a unidirectional ventilation experiment environment is formed, and uniform and stable environmental wind can be provided.

2. The solid fuel angle-variable fire spread experimental device under the action of the ambient wind as claimed in claim 1, characterized in that: different components of the experiment table are connected through bolts, the components can be detached, and a plurality of material supporting plates with different sizes and measuring positions are designed for researching the combustion characteristics of solid fuels with different sizes.

3. The solid fuel angle-variable fire spread experimental device under the action of the ambient wind as claimed in claim 1, characterized in that: the solid fuel is a combustible solid material, in particular to acrylic, a wood material, a building heat-insulating material XPS or a plywood.

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