A double-chamber fire spread experimental device and method based on constant-liquid-level oil pool fire source

Abstract

The application provides a double-chamber fire spread experimental device and method based on a constant-liquid-level oil pool fire source, which can be applied to the technical field of building fire safety. The device comprises a combustion chamber, a first window opening is arranged on the combustion chamber, and a first glass component is installed at the first window opening; the fire receiving chamber is arranged opposite to the combustion chamber, and a second window opening is arranged on the side facing the combustion chamber, a second glass component is installed at the second window opening, and a combustible material arrangement area is arranged in the fire receiving chamber; a spacing adjustment assembly is connected to the combustion chamber and the fire receiving chamber, and is used for driving the combustion chamber and the fire receiving chamber to relatively move along a preset direction; and a constant-liquid-level oil pool fire source assembly comprises a combustion disc arranged in the combustion chamber, and the combustion disc is used for containing fuel. The application can improve the repeatability and reliability of experimental conditions.

Description

Technical Field

[0001] This application relates to the field of fire simulation research, and more specifically to a dual-chamber fire spread experimental device and method based on a constant-level oil tank fire source. Background Technology

[0002] With the increasing density of urban buildings and the widespread use of glass windows on building facades, the risk of fire spreading to adjacent buildings due to flames spilling out of openings is growing. In actual fires, flames and high-temperature smoke from burning combustibles inside a burning building overflow through openings such as windows, exerting a continuous thermal effect on the glass components of adjacent building facades. When the glass components of adjacent buildings crack or detach under this thermal effect, new ventilation openings are created on their facades. Flames and high-temperature smoke can then enter the interior and ignite internal combustibles, causing the fire to spread from the exterior of the building to the interior of adjacent buildings.

[0003] In related technologies, fire spread experimental equipment mostly focuses on the development of single-chamber fires, flame overflow from windows, or indoor smoke flow. It struggles to simultaneously simulate the external heating of adjacent building glass components by overflowing flames, the formation of new ventilation openings due to glass breakage, and the overall fire spread process after flames enter adjacent buildings. Some dual-chamber experimental equipment primarily studies indoor ventilation and smoke flow through doors or connecting corridors, failing to reflect the relationship between building spacing, thermal breakage of exterior window glass, and the ignition of combustibles inside adjacent chambers.

[0004] Therefore, it is necessary to provide an experimental device that can adjust the distance between adjacent chambers and has a continuously burning fire source to simulate the flame overflow after the glass of the first chamber breaks, so as to study the fire spread process under the action of the overflow flame in the dual chambers. Summary of the Invention

[0005] In view of the above problems, embodiments of this application provide a dual-chamber fire spread experimental device and method based on a constant-level oil tank fire source.

[0006] According to a first aspect of this application, a dual-chamber fire spread experimental device based on a constant-level oil tank ignition source is provided, comprising: a combustion chamber having a first window opening and a first glass component installed at the first window opening; a fire-receiving chamber being disposed opposite to the combustion chamber, with a second window opening on the side facing the combustion chamber, a second glass component installed at the second window opening, and a combustible material arrangement area inside the fire-receiving chamber; a spacing adjustment assembly connecting the combustion chamber and the fire-receiving chamber for driving the combustion chamber and the fire-receiving chamber to move relative to each other along a preset direction; and a constant-level oil tank ignition source assembly including a combustion plate disposed in the combustion chamber and a liquid level control device connected to the combustion plate, the combustion plate being used to hold fuel and the fuel supply in the combustion plate being adjusted by the liquid level control device.

[0007] According to a second aspect of this application, a dual-chamber fire spread test method based on a constant-level oil pool ignition source is provided, applied to the aforementioned dual-chamber fire spread test apparatus based on a constant-level oil pool ignition source. The method includes: adjusting the spatial distance between the combustion chamber and the fire-receiving chamber to a target distance indicated by the test conditions using a spacing adjustment component; arranging combustibles in the combustible arrangement area of ​​the fire-receiving chamber; activating the constant-level oil pool ignition source component, whereby the ignition source in the combustion chamber heats and causes a first glass component to rupture, and flames overflow outward through a first window opening, externally heating a second glass component, causing the second glass component to rupture or detach, and forming a new ventilation opening at the second window opening; flames and high-temperature flue gas entering the fire-receiving chamber through the new ventilation opening, heating the combustibles, and monitoring the thermal response of the combustibles and whether ignition occurs; continuously acquiring parameter data from the activation of the constant-level oil pool ignition source component to the initiation of fire spread until its end, the parameter data including at least image data of the combustion chamber and the fire-receiving chamber.

[0008] This application provides a dual-chamber fire spread experimental device and method based on a constant-level oil tank ignition source. The constant-level oil tank ignition source component achieves a continuous and stable ignition source intensity during combustion. By adjusting the distance between the chambers using a spacing adjustment component, it is possible to study the thermal intensity and fire spread impact of overflow flames on adjacent building glass components under different building spacing conditions. This improves the repeatability and comparability of experimental conditions. During the flame spread experiment, it allows for the analysis of the timing of glass breakage and detachment, the formation process of new ventilation openings, internal temperature changes within the chambers, and flame morphology, providing reliable experimental evidence for building fire separation spacing design and fire spread mechanism research. Attached Figure Description

[0009] The above-mentioned contents, other objects, features and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0010] Figure 1 A schematic diagram of the structure of the dual-chamber fire spread experimental device based on a constant-level oil tank fire source according to an embodiment of this application is shown.

[0011] Figure 2 A schematic diagram of the window frame and glass mounting structure according to an embodiment of this application is shown.

[0012] Figure 3 The diagram shows a schematic of the chamber structure of the dual-chamber fire spread experimental device based on a constant-level oil tank fire source under different spacing conditions according to an embodiment of this application.

[0013] Figure 4 A schematic diagram of a constant-level oil tank ignition source assembly according to an embodiment of this application is shown.

[0014] Figure 5 A flowchart of a dual-chamber fire spread experimental setup based on a constant-level oil tank fire source, according to an embodiment of this application, is shown.

[0015] Reference numerals: 1. Combustion chamber; 2. Receiving chamber; 3. Constant-level oil tank ignition source assembly; 6. Image acquisition system; 7. Heat release rate measurement system; 8. Spacing adjustment assembly; 9. First door opening; 10. First window opening; 11. First window frame structure; 12. First glass component; 13. Second window opening; 14. Second window frame structure; 15. Second glass component; 16. Combustible material arrangement area; 17. Combustible material fixing bracket; 18. Combustion plate; 19. Main storage tank; 20. Balance level tank; 21. Level control device; 22. Waste liquid recovery device; 23. Water circulation tank; 24. Connecting pipeline; 25. Float valve; 29. ​​High-speed camera; 30. Infrared thermal imager; 31. Smoke hood; 32. Smoke exhaust pipe; 33. Gas concentration analyzer; 34. Guide pulley; 35. Locking component. Detailed Implementation

[0016] The embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of this application. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of this application for ease of explanation. However, it will be apparent that one or more embodiments may be implemented without these specific details. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of this application.

[0017] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0018] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0019] Example 1

[0020] like Figures 1 to 4 As shown in the figure, this application provides a dual-chamber fire spread experimental device based on a constant-level oil pool fire source, including: a combustion chamber 1, a fire-receiving chamber 2, a spacing adjustment component 8, and a constant-level oil pool fire source component 3.

[0021] The combustion chamber 1 is provided with a first window opening 10, and a first glass component 12 is installed at the first window opening 10; the receiving chamber 2 is arranged opposite to the combustion chamber 1, and a second window opening 13 is provided on the side facing the combustion chamber 1, and a second glass component 15 is installed at the second window opening 13; the receiving chamber 2 is provided with a combustible material arrangement area 16; the spacing adjustment component 8 connects the combustion chamber 1 and the receiving chamber 2, and is used to drive the combustion chamber 1 and the receiving chamber 2 to move relative to each other in a preset direction; the constant liquid level oil pool ignition source component 3 includes a combustion plate 18 disposed in the combustion chamber 1 and a liquid level control device 21 connected to the combustion plate 18. The combustion plate 18 is used to hold fuel and the amount of fuel replenishment in the combustion plate 18 is adjusted by the liquid level control device 21.

[0022] Combustion chamber 1 is used to simulate the interior space of a burning building. Combustion chamber 1 includes multiple walls that enclose the interior space for simulating a fire. A first door opening 9 is provided on one side of combustion chamber 1, and a first window opening 10 is provided on the other side. The first door opening 9 simulates a ventilation entrance in a building room, and the first window opening 10 simulates a window where flames overflow during fire development. A first window frame structure 11 and a first glass component 12 are installed at the first window opening 10. Fire-affected chamber 2 is located opposite combustion chamber 1 and is used to simulate the interior space of an adjacent fire-affected building. A second window opening 13 is provided on the side of fire-affected chamber 2 facing combustion chamber 1. A second window frame structure 14 and a second glass component 15 are installed at the second window opening 13. The interior of fire-affected chamber 2 includes a combustible material arrangement area 16 and a combustible material fixing bracket 17. Combustible material fixing bracket 17 is used to fix or support the combustible material to be tested, so that the combustible material can be arranged in different positions inside the fire chamber 2, thereby studying the process of flame and high-temperature smoke entering the fire chamber 2 and causing the combustible material to be heated, carbonized or ignited after the second glass component 15 breaks to form a ventilation opening.

[0023] For example, the internal dimensions of both the combustion chamber 1 and the fire-receiving chamber 2 are 0.9 m × 0.6 m × 0.6 m, used to simulate a 1 / 4 ISO 9705 scale room. The walls of the combustion chamber 1 and the fire-receiving chamber 2 can be made of 20 mm thick aluminum silicate fireproof board, calcium silicate board, vermiculite board, or other high-temperature resistant heat-insulating materials to ensure that the chambers have good fire resistance and heat insulation during the experiment.

[0024] It should be noted that ISO 9705, "Fire tests - Full-scale room tests on surface products," is a highly efficient and representative large-scale real-world fire scenario simulation testing standard developed by the International Organization for Standardization (ISO). It is specifically designed to evaluate the contribution of wall and ceiling panels (surface products) to the development of fires after flashover under near-real-world conditions (installed in a room). A 1 / 4 scale ISO 9705 room is a scaled-down fire test model created by geometrically reducing the full-scale test room (3.6 m long, 2.4 m wide, 2.4 m high; doorway 0.8 m wide, 2.0 m high) according to the ISO 9705 standard. It is used to reproduce and study the dynamic behavior of indoor fires, flashover, and other special phenomena at a safer, more controllable, and lower-cost smaller scale, as well as to assess the impact of different building decoration materials on fire development. Note that 1 / 4 is not the only scale standard; other scales such as 2 / 5, 1 / 2, and 1 / 5 can also be used, depending on the specific experimental design requirements.

[0025] like Figures 1-2 As shown, the first door opening 9 of the combustion chamber 1 is located on the side wall facing away from the fire-receiving chamber 2, and the size of the first door opening 9 can be 0.5 m × 0.2 m. The first window opening 10 is located on the side wall of the combustion chamber 1 facing the fire-receiving chamber 2, and the size of the first window opening 10 is 0.4 m × 0.3 m. The upper edge of the first window opening 10 is about 0.1 m away from the top plate of the combustion chamber 1. The second window opening 13 is located on the side wall of the fire-receiving chamber 2 facing the combustion chamber 1, and the size of the second window opening 13 corresponds to the first window opening 10, which is 0.4 m × 0.3 m, so that the overflow flame generated in the combustion chamber 1 can act on the outer surface of the second glass component 15.

[0026] The dimensions of the first glass component 12 and the second glass component 15 are respectively matched with the dimensions of the corresponding first window opening 10 and second window opening 13. For example, when the dimensions of both the first window opening 10 and the second window opening 13 are 0.4 m × 0.3 m, the dimensions of the first glass component 12 and the second glass component 15 are also 0.4 m × 0.3 m. The thickness of the first glass component 12 and the second glass component 15 is 6 mm. Depending on the experimental requirements, the first glass component 12 and the second glass component 15 can be made of float glass, tempered glass, laminated glass, or insulated glass. In a preferred embodiment, the second glass component 15 can be made of 6 mm thick float glass or 6 mm thick tempered glass to compare the effects of different glass materials on cracking, detachment, and fire spread under the influence of an overflow flame.

[0027] Both the first window frame structure 11 and the second window frame structure 14 include a metal frame and a clamping and fixing assembly. The clamping and fixing assembly is disposed on the metal frame and is used to fix the first glass component 12 and the second glass component 15 within the corresponding metal frame. The clamping and fixing assembly may include one or more of a pressure plate, bolts, clips, and clamps. This structure allows for the replacement of different types of glass components and enables the simulation of the thermal cracking process of building exterior windows under different boundary constraint conditions.

[0028] like Figure 3 As shown, the spatial distance between the combustion chamber 1 and the flame-receiving chamber 2 is adjusted by a spacing adjustment assembly 8. The spacing adjustment assembly 8 may include a guide pulley 34 and a locking member 35. The guide pulley 34 can drive the combustion chamber 1 and the flame-receiving chamber 2 to move relative to each other, thereby changing the distance between them. The locking member 35 can lock the guide pulley, thereby fixing the chamber positions at a predetermined spacing to ensure that the spatial distance between the two chambers remains stable during the experiment. In some embodiments, the initial distance between the two chambers can be set to 0.25 m, and can be adjusted to 0.15 m, 0.20 m, 0.30 m, 0.35 m, or other preset distances according to the experimental conditions. Subsequently, the guide pulley 34 can drive the combustion chamber 1 and the flame-receiving chamber 2 to move relative to each other, thereby gradually reducing the distance between them to 0.125 m, and can be adjusted to other preset distances according to the experimental conditions.

[0029] like Figure 1 and Figure 4As shown, the constant-level oil tank ignition source assembly 3 is installed inside the combustion chamber 1 to provide a continuous and stable combustion ignition source to the combustion chamber 1. The constant-level oil tank ignition source assembly 3 includes a combustion plate 18, a main storage tank 19, a balance level tank 20, and a waste liquid recovery device 22. The main storage tank 19 is connected to the balance level tank 20 via a pipeline, and the balance level tank 20 is connected to the bottom of the combustion plate 18 via a pipeline. The controlled fuel level in the balance level tank 20 and the target fuel level in the combustion plate 18 are at the same horizontal level. The level control device 21 is used to control the fuel level in the balance level tank 20 to maintain a constant fuel level in the combustion plate 18, thereby forming a continuous and stable combustion ignition source during the experiment.

[0030] In some embodiments, the combustion disk 18 can be a 200 mm × 200 mm square metal combustion disk, disposed inside the combustion chamber 1, and located at or near the vertical center line of the first window opening 10. The combustion disk 18 can contain n-heptane as liquid fuel, with a purity of 99.5%. Other liquid fuels may also be used depending on experimental requirements. The flame generated after combustion in the combustion disk 18 develops within the combustion chamber 1 and overflows outward through the first window opening 10, externally heating the second glass component 15 of the flame-receiving chamber 2.

[0031] The fuel level control device 21 controls the fuel supply to the combustion pan 18 based on changes in the fuel level, thereby maintaining the fuel level in the combustion pan 18 within a preset range. The fuel level control device 21 includes a float valve 25, which is located within the balance level tank 20. The float valve 25 includes a float and a valve; the float floats on the fuel surface in the balance level tank 20 and is connected to the valve. When the fuel level in the balance level tank 20 decreases, the float descends with the liquid level, opening the valve and allowing fuel from the main storage tank 19 to be added to the balance level tank 20. When the fuel level in the balance level tank 20 reaches a predetermined height, the float rises with the liquid level, closing the valve and thus maintaining the stability of the fuel level in the balance level tank 20 and the combustion pan 18. This structure reduces the impact of fuel level drops during combustion on combustion intensity, flame height, and heat release rate, improving the stability, repeatability, and data comparability of experimental conditions.

[0032] Please refer to again Figure 1 and Figure 3 For example, the experimental apparatus also includes a measurement system for acquiring parameter data, including temperature data, wind speed data, image data, and heat release rate data during fuel combustion. The measurement system includes a temperature and heat flow measurement system, a wind speed measurement system, an image acquisition system 6, and a heat release rate measurement system 7.

[0033] The temperature and heat flux measurement system includes a space temperature measurement component, a surface temperature measurement component, and a heat flux density measurement component. The space temperature measurement component may include a thermocouple tree or thermocouple array for measuring the gas temperature distribution inside the combustion chamber 1, inside the flame-receiving chamber 2, and in the space between the two chambers. The surface temperature measurement component may include patch thermocouples, an infrared thermal imager, or a surface temperature sensor for measuring temperature changes on the surfaces of the second glass member 15, the second window frame structure 14, and the combustible material inside the flame-receiving chamber 2. The heat flux density measurement component measures the heat flux intensity near the second glass member 15 or in the space between the two chambers under the influence of an overflow flame.

[0034] In some embodiments, the space temperature measurement component may employ a K-type thermocouple tree or a K-type thermocouple array. The thermocouple probe diameter is 1.0 mm. Thermocouple trees may be arranged inside the combustion chamber 1, inside the flame-receiving chamber 2, and in the space between the two chambers. Each set of thermocouple trees may have multiple measuring points along the height direction to obtain the gas temperature distribution at different heights. The surface temperature measurement component may employ patch thermocouples, which may be arranged on the outer surface and inner surface of the second glass component 15, the surface of the second window frame structure 14, and the surface of the combustible material inside the flame-receiving chamber 2 to obtain the surface temperature changes of the glass component, window frame structure, and combustible material during the heating process.

[0035] In some embodiments, the heat flux density measurement assembly includes a dual-head heat flux meter. The dual-head heat flux meter includes a first heat flux measuring end and a second heat flux measuring end. The first heat flux measuring end has a range of 100 kW / m³. 2 The range of the second heat flow measurement terminal is 50 kW / m. 2 A dual-head heat flux meter can be positioned near the second window opening 13 of the fire-receiving chamber 2 to measure the heat flux density under direct contact with overflowing flames, thermal radiation, and thermal convection. By using heat flux measurement ends with different ranges, the measurement needs of both high and relatively low heat flux intensity areas can be met, thereby improving the applicability of heat flux density data.

[0036] The wind speed measurement system includes a pitot tube and a differential pressure gauge. The pitot tube is positioned at the first opening 9 of the combustion chamber 1 to measure the wind speed distribution entering the combustion chamber 1. It can also be positioned in the space between the combustion chamber 1 and the fire-receiving chamber 2 to measure the wind speed changes in the flow field around the overflow flame. The differential pressure gauge is connected to the pitot tube and is used to collect differential pressure data and convert it into wind speed data.

[0037] In some embodiments, the differential pressure gauge can be connected to a 607-01 or 607-11 data conversion module. Based on the differential pressure measured by the pitot tube and the output voltage of the data conversion module, the corresponding differential pressure data can be obtained. For the 607-01 conversion module, its output voltage and differential pressure satisfy the following relationship: For the 607-11 type conversion module, the output voltage and voltage difference satisfy the following: .in, This is the pressure difference, expressed in Pa. This is the output voltage of the differential pressure sensor, in volts (V).

[0038] Based on the pressure difference measured by the pitot tube, the wind speed at the measuring point can be calculated using the following formula:

[0039] ,

[0040] in, The wind speed at the measuring point is expressed in m / s. The correction factor for the Pitot tube is 0.84 in this embodiment; This is the pressure difference, expressed in Pa. Air density, unit: kg / m³ 3 Air density This can be calculated based on the experimental environment temperature. Through the above calculations, the wind speed distribution at the first door opening (9) and in the space between the two chambers can be obtained, thus analyzing the influence of wind speed changes on the flame overflow pattern, the thermal cracking of the second glass component (15), and the fire spread process. Furthermore, air density... The following formula can be used for calculation:

[0041] ,

[0042] in, Atmospheric pressure, in Pa; Let J be the gas constant for air, taken as 287 J / (kg·K); The air temperature is expressed in Kelvin (K).

[0043] Image acquisition system 6 includes a high-speed camera 29 and an infrared thermal imager 30. The high-speed camera 29 is used to acquire data on the fire development process within the combustion chamber 1, the morphology of flames overflowing through the first window opening 10, the formation, propagation, partial or complete detachment of cracks in the second glass component 15, and the heating, carbonization, or ignition process of combustibles inside the fire-affected chamber 2. The infrared thermal imager 30 is used to acquire data on temperature field changes in the glass component, window frame structure, and exterior facade of the chamber. For example, the high-speed camera 29 has a resolution of 1920 × 1080 pixels and a frame rate of 120 fps or higher. The high-speed camera 29 and the infrared thermal imager 30 are synchronized via a synchronization trigger device or a unified time reference to analyze the temporal relationships during the glass heating, cracking, and detachment processes.

[0044] The heat release rate measurement system 7 includes a smoke hood 31, a smoke exhaust pipe 32, and a gas analysis device, wherein the gas analysis device is a gas concentration analyzer 33. The smoke hood 31 is used to collect the flue gas generated during the combustion of the fire source in the combustion chamber 1, the smoke exhaust pipe 32 is used to transport the flue gas, and the gas concentration analyzer 33 is used to measure the oxygen concentration, carbon dioxide concentration, and carbon monoxide concentration in the flue gas.

[0045] It should be noted that the oxygen consumption principle states that during complete combustion, a certain amount of heat is generated for every unit mass of oxygen consumed. Therefore, based on the oxygen consumption principle, the heat release rate during the combustion process of a fire source can be calculated, thus providing a data basis for analyzing fire source intensity, overflow flame morphology, and glass breakage behavior.

[0046] In some embodiments, the heat release rate can be calculated according to the oxygen consumption principle. The heat release rate data can be used to determine whether the constant liquid level oil tank fire source component 3 can provide a stable fire source during the experiment, and provide a basis for the analysis of overflow flame intensity, glass component breakage and fire spread behavior.

[0047] During the experiment, after the ignition source in combustion chamber 1 is ignited, the flame develops inside combustion chamber 1. When the flame overflows outward through the first window opening 10, the overflowing flame heats the second glass component 15 on the outer facade of the chamber 2 through direct contact, thermal radiation, and thermal convection. As the temperature of the second glass component 15 rises and thermal stress is generated, the second glass component 15 may crack, crack propagate, partially detach, or detach entirely. When the second glass component 15 cracks or detaches, the second window opening 13 forms a new ventilation opening, through which flames and high-temperature flue gas can enter the interior of the chamber 2, heating the combustibles inside, thereby causing the combustibles to heat up, carbonize, smolder, or ignite with an open flame.

[0048] In some embodiments, the moment when the glass breaks can be determined based on the time when the second glass component 15 first appears to crack in the image recorded by the high-speed camera 29; the moment when the glass falls off can be determined based on the time when the second glass component 15 partially or entirely detaches from the second window frame structure 14; the moment when the combustible material ignites can be determined based on the time when a continuous open flame appears on the surface of the combustible material inside the fire chamber 2; and the moment when the temperature inside the fire chamber 2 suddenly increases can be determined based on the temperature curve collected by the temperature and heat flow measurement system.

[0049] Depending on the experimental requirements, combustible materials may include combustible polymers, wood, and other combustible organic materials. The size, arrangement, and quantity of combustible materials can be adjusted according to the experimental conditions. The combustible material fixing bracket 17 can be configured with combinations of different heights and positions to study the thermal response and ignition behavior of combustible materials at different locations after the flame enters the flame-receiving chamber 2.

[0050] The experimental equipment of this application can also be used to study fire spread behavior under different working conditions by changing the following parameters: changing the distance between the combustion chamber 1 and the fire-receiving chamber 2; changing the thickness or material of the first glass component 12 and the second glass component 15; and changing the location or type of combustibles inside the fire-receiving chamber 2. By adjusting the above parameters, the influence of factors such as building spacing, glass type, and combustible arrangement on the cracking of glass components and fire spread behavior under the action of spilled flames can be systematically studied.

[0051] In some embodiments, the constant-level oil tank ignition source assembly 3 further includes a water circulation tank 23. The water circulation tank 23 is used to cool the combustion plate 18 to control its temperature, prevent deformation, and reduce fuel evaporation and thermal decomposition, thereby improving experimental safety. The water circulation tank 23 is connected to the combustion plate 18 via a connecting pipe 24 to form a cooling loop, ensuring that the combustion plate 18 can maintain a low temperature.

[0052] After the experiment, the remaining or overflowing fuel in the combustion pan 18 and the balance tank 20 is recovered through the waste liquid recovery device 22. The waste liquid recovery device 22 is connected to the combustion pan 18 and the balance tank 20 to ensure safe cleanup and fuel recovery after the experiment.

[0053] Example 2

[0054] like Figure 5 As shown, this embodiment provides a dual-chamber fire spread test method based on a constant-level oil tank fire source, applied to the dual-chamber fire spread test device based on a constant-level oil tank fire source in Embodiment 1. The method includes the following steps:

[0055] Step S1: According to the experimental conditions, the spatial distance between the combustion chamber 1 and the fire-receiving chamber 2 is adjusted to the target distance indicated by the experimental conditions through the spacing adjustment component 8.

[0056] Prior to this, a first glass component 12 needs to be installed at the first window opening 10 of the combustion chamber 1, and a second glass component 15 needs to be installed at the second window opening 13 of the fire-bearing chamber 2. The specifications of the first glass component 12 and the second glass component 15 are determined according to the experimental conditions. In this embodiment, the first glass component 12 is made of 6 mm thick float glass, and the second glass component 15 is made of 6 mm thick tempered glass, to compare the cracking and detachment behavior of different glass materials under the action of overflow flames. The first glass component 12 and the second glass component 15 are fixed in the first window frame structure 11 and the second window frame structure 14 respectively by clamping and fixing components. The tightness of the clamping and fixing components is adjusted according to the experimental conditions to simulate the boundary constraint conditions of different building windows.

[0057] According to the experimental conditions, the spatial distance between the combustion chamber 1 and the flame-receiving chamber 2 is adjusted by the spacing adjustment component 8. In this embodiment, the combustion chamber 1 and the flame-receiving chamber 2 are first moved relative to each other in a preset direction by the guide pulley 34 so that the distance between the two chambers reaches the target value, for example, 0.25 m. Then, the guide pulley 34 is locked by the locking component 35 so that the two chambers maintain a fixed distance during the experiment.

[0058] Step S2: Arrange combustibles in the combustible arrangement area 16 of the fire-receiving chamber 2.

[0059] In this embodiment, the combustible material is polyurethane foam board with a density of 40 kg / m³. 3 The dimensions of the combustible material are 0.2 m × 0.2 m × 0.05 m, and the dimensions of the pine strips are 0.15 m × 0.02 m × 0.02 m, which are placed at different positions on the combustible material fixing bracket 17. Polyurethane foam boards are arranged near the second window opening 13, and combustible materials are arranged at different positions within the chamber to study the thermal response and ignition delay time of combustible materials of different positions and materials after the flame and high-temperature smoke enter the ignition chamber 2. The height of the combustible material fixing bracket 17 is adjusted according to the experimental conditions so that the surface of the combustible material is at the same level as the lower edge of the second window opening 13 or at different heights.

[0060] A measurement system is arranged inside the combustion chamber 1, the receiving chamber 2, and the space between the two chambers. In this embodiment, the space temperature measurement component uses a K-type thermocouple tree, which is arranged at the center of the combustion chamber 1, the receiving chamber 2, and the space between the two chambers. Each thermocouple tree has 5 measuring points along the height direction, with a spacing of 0.1 m between the measuring points, to obtain the gas temperature distribution at different heights. The surface temperature measurement component uses patch thermocouples, which are arranged at the center point of the outer surface of the second glass component 15, the upper edge of the second window frame structure 14, and the center point of the upper surface of the polyurethane foam board. The heat flux density measurement component uses a dual-head heat flux meter, which is arranged at the center point of the outer surface of the second window opening 13. The first heat flux measuring end of the dual-head heat flux meter has a range of 100 kW / m. 2 Facing the first window opening 10, the second heat flow measuring end of the dual-head heat flow meter has a range of 50 kW / m. 2Facing downwards. A pitot tube is positioned at the center of the first door opening 9, and a differential pressure gauge is connected to the pitot tube via a data conversion module. A high-speed camera 29 is positioned to the side front of the space between the two chambers, with its lens facing the first window opening 10 and the second window opening 13, for simultaneously acquiring the flame overflow pattern and the glass breakage process. An infrared thermal imager 30 is positioned to the side front of the fire-affected chamber 2, with its lens facing the second glass component 15, for acquiring the temperature field changes of the glass component and window frame structure. A smoke hood 31 is located 0.3 m above the top plate of the combustion chamber 1, and a smoke exhaust pipe 32 connects the smoke hood 31 and the gas analysis device.

[0061] Step S3: Start the constant liquid level oil tank ignition source assembly 3. The ignition source in the combustion chamber 1 heats and causes the first glass component 12 to break. The flame overflows outward through the first window opening 10, externally heating the second glass component 15, causing the second glass component 15 to break or fall off, and forming a new ventilation opening at the second window opening 13.

[0062] When the ignition source is started, the outlet valve of the main storage tank 19 is opened, allowing fuel to flow into the balance level tank 20 through the pipeline. The float valve 25 automatically controls the fuel replenishment amount according to the fuel level in the balance level tank 20. When the fuel level in the balance level tank 20 and the combustion plate 18 reaches a predetermined height, for example, 20 mm, the float valve automatically closes. After combustion consumption causes the level to drop, the float valve automatically opens and replenishes fuel to maintain a stable fuel level in the combustion plate. The fuel in the combustion plate 18 is ignited, forming a continuous and stable combustion source in the combustion chamber 1. In this embodiment, the fuel used is n-heptane with a purity of 99.5%, and the combustion plate 18 is a 200 mm × 200 mm square metal combustion plate. After ignition, the flame develops inside the combustion chamber 1, and the first glass component 12 gradually heats up under the action of heat. As the temperature inside the combustion chamber 1 rises, the first glass component 12 cracks due to thermal stress and eventually breaks, forming a first ventilation opening, through which the flame overflows outward through the first window opening 10.

[0063] In step S4, flames and high-temperature flue gas enter the fire chamber 2 through a new ventilation opening to heat the combustibles and monitor the thermal response of the combustibles and whether ignition occurs.

[0064] Step S5: During the process of starting the constant liquid level oil tank fire source component 3 and initiating fire spread, parameter data is continuously acquired. The parameter data includes at least image data of the combustion chamber 1 and the fire-receiving chamber 2.

[0065] Specifically, the overflowing flame externally heats the second glass component 15 through direct contact, thermal radiation, and thermal convection. A temperature and heat flux measurement system simultaneously acquires the outer surface temperature of the second glass component 15, the internal gas temperature of the flame-receiving chamber 2, and the heat flux density at the second window opening 13. An image acquisition system 6 simultaneously records the flame overflow pattern and the process of crack initiation and propagation in the second glass component 15.

[0066] As the temperature of the second glass component 15 continues to rise and reaches the rupture threshold, cracks form, the cracks propagate, and the component partially or completely detaches, creating a new ventilation opening at the second window opening 13. The wind speed measurement system monitors the incoming wind speed at the first door opening 9 in real time to analyze the impact of ventilation conditions on flame overflow and fire spread. The heat release rate measurement system 7 collects the oxygen, carbon dioxide, and carbon monoxide concentrations in the flue gas using a gas analysis device and calculates the heat release rate of the fire source in real time based on the oxygen consumption principle to verify the stability of the fire source.

[0067] Flames and high-temperature flue gas enter the combustion chamber 2 through a new ventilation opening, heating the combustibles in the combustible material arrangement area 16. A temperature and heat flow measurement system records the temperature change curve inside the combustion chamber 2, while an image acquisition system 6 records the entire process of the combustibles being heated, carbonized, smoldering, or ignited by an open flame. After the experiment, the remaining fuel in the equilibrium level tank 20 is recovered through a waste liquid recovery device 22.

[0068] In this embodiment, the critical event moments are determined in the following ways: the moment the first glass component 12 breaks is determined based on the time when the first crack first appears in the image recorded by the high-speed camera 29; the moment the second glass component 15 breaks is determined based on the time when the second glass component 15 first appears in the image recorded by the high-speed camera 29; the moment the second glass component 15 detaches is determined based on the time when part or all of the second glass component 15 detaches from the second window frame structure 14 in the image recorded by the high-speed camera 29; the moment the combustible material ignites is determined based on the time when a continuous open flame appears on the surface of the combustible material in the image recorded by the high-speed camera 29, or based on the time when the temperature inside the fire chamber 2 suddenly increases in the temperature curve collected by the temperature and heat flow measurement system.

[0069] Through the above steps, the following experimental data can be obtained: the fracture time, detachment time, and fracture mode of the first glass component 12 and the second glass component 15; the temperature change curve and heat flux density change curve of the outer surface of the second glass component 15; the gas temperature distribution and temperature change curve inside the fire-affected chamber 2; the wind speed distribution at the first door opening 9 and the space between the two chambers; the heat release rate curve of the fire source; and high-speed camera images and infrared thermographic data of the flame overflow morphology, glass fracture process, and the entire fire spread process. Based on the above data, the fracture mechanism of the glass components under the action of the overflowing flame, the formation process of the new ventilation opening, and the fire spread behavior inside the adjacent chambers can be systematically analyzed.

[0070] In summary, this application, through the collaborative design of a dual-chamber structure, a constant-level oil tank ignition source assembly, replaceable glass components and clamping and fixing components, and a multi-parameter synchronous measurement system, has achieved experimental simulation of the entire process of glass component breakage and fire spread under the action of overflow flames between buildings. It solves the technical problems in the prior art where experimental equipment cannot simulate the complete fire spread process, the ignition source intensity is unstable, and the coupling effect of multiple factors cannot be studied. It has significant experimental research value and engineering application value.

[0071] Those skilled in the art will understand that the features described in the various embodiments of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application.

Claims

1. A dual-chamber fire spread experimental device based on a constant-level oil tank ignition source, characterized in that, include: Combustion chamber (1), the combustion chamber (1) is provided with a first window opening (10), and a first glass component (12) is installed at the first window opening (10); Fire-receiving chamber (2), which is arranged opposite to the combustion chamber (1), and a second window opening (13) is provided on the side facing the combustion chamber (1). A second glass component (15) is installed at the second window opening (13). A combustible material arrangement area (16) is provided inside the fire-receiving chamber (2). A spacing adjustment component (8) is connected to the combustion chamber (1) and the fire-receiving chamber (2) for driving the combustion chamber (1) and the fire-receiving chamber (2) to move relative to each other in a preset direction; The constant level oil tank ignition source assembly (3) includes a combustion plate (18) disposed in the combustion chamber (1) and a liquid level control device (21) connected to the combustion plate (18). The combustion plate (18) is used to hold fuel and the amount of fuel replenishment in the combustion plate (18) is adjusted by the liquid level control device (21).

2. The dual-chamber fire spread experimental device based on a constant-level oil tank fire source according to claim 1, characterized in that, A first window frame structure (11) is provided at the first window opening (10), and a second window frame structure (14) is provided at the second window opening (13). Both the first window frame structure (11) and the second window frame structure (14) include a metal frame and a clamping and fixing component. The clamping and fixing component includes at least one of a pressure plate, a bolt, a buckle, and a clamp. The clamping and fixing component is used to fix the first glass component (12) and the second glass component (15) in the corresponding metal frame.

3. The dual-chamber fire spread experimental device based on a constant-level oil tank fire source according to claim 1, characterized in that, The spacing adjustment assembly (8) includes a guide pulley (34) and a locking member (35) located at the bottom of the combustion chamber (1) and the fire-receiving chamber (2). The combustion chamber (1) and the fire-receiving chamber (2) move relative to each other in a preset direction via the guide pulley (34) and are fixed at a predetermined spacing via the locking member (35).

4. The dual-chamber fire spread experimental device based on a constant-level oil tank fire source according to claim 1, characterized in that, The constant level oil tank ignition source assembly (3) also includes a liquid storage assembly, which is connected to the combustion plate (18). The liquid storage assembly includes a main liquid storage tank (19) and a balance level tank (20). The main liquid storage tank (19) is connected to the balance level tank (20). The balance level tank (20) is connected to the bottom of the combustion plate (18) through a pipeline. The balance level tank (20) is flush with the fuel liquid level in the combustion plate (18). The liquid level control device (21) controls the fuel supply to the combustion plate (18) according to the fuel liquid level change, so that the fuel liquid level in the combustion plate (18) is maintained within a preset range.

5. The dual-chamber fire spread experimental device based on a constant-level oil tank fire source according to claim 4, characterized in that, The liquid level control device (21) includes a float valve (25), which is located in the balance liquid level tank (20). The float valve (25) includes a float and a valve. The float floats on the fuel liquid surface in the balance liquid level tank (20) and is connected to the valve. The float moves with the rise and fall of the fuel liquid level, thereby controlling the flow of fuel from the total storage tank (19) to the balance liquid level tank (20).

6. The dual-chamber fire spread experimental device based on a constant-level oil tank fire source according to claim 1, characterized in that, It also includes a measurement system for acquiring parameter data, which includes temperature data, wind speed data, image data, and heat release rate data during fuel combustion.

7. The dual-chamber fire spread experimental device based on a constant-level oil tank fire source according to claim 6, characterized in that, The measurement system includes a temperature and heat flow measurement system, a wind speed measurement system, an image acquisition system (6), and a heat release rate measurement system (7), wherein: The temperature and heat flux measurement system includes a space temperature measurement component, a surface temperature measurement component, and a heat flux density measurement component. The space temperature measurement component includes a thermocouple tree or a thermocouple array and is disposed inside the combustion chamber (1), inside the fire-receiving chamber (2), and in the space between the two chambers. The surface temperature measurement component includes a patch thermocouple or a surface temperature sensor and is disposed on the surface of combustible material inside the second glass component (15), the second window frame structure (14), and the fire-receiving chamber (2). The heat flux density measurement component includes a dual-head heat flux meter and is disposed at the second window opening (13). The wind speed measurement system includes a Pitot tube and a differential pressure gauge connected to the Pitot tube, wherein the Pitot tube is located at the door opening of the combustion chamber (1); The image acquisition system (6) includes multiple high-speed cameras (29) and infrared thermal imagers (30), with the high-speed cameras (29) and the infrared thermal imagers (30) both facing the first window opening (10) and the second window opening (13); The heat release rate measurement system (7) includes a smoke hood (31), a smoke exhaust pipe (32) and a gas analysis device. The smoke hood (31) is located above the combustion chamber (1) and is connected to the smoke exhaust pipe (32). The gas analysis device is connected to the smoke exhaust pipe (32).

8. The dual-chamber fire spread experimental device based on a constant-level oil tank fire source according to claim 1, characterized in that, The combustible material arrangement area (16) is provided with several combustible material fixing brackets (17), and combustible materials are arranged on the combustible material fixing brackets (17).

9. The dual-chamber fire spread experimental device based on a constant-level oil tank fire source according to claim 1, characterized in that, The combustion chamber (1) is provided with a first door opening (9), which is located on the side opposite to the first window opening (10); the fire-receiving chamber (2) is provided with a second door opening, which is located on the side opposite to the second window opening (13).

10. A dual-chamber fire spread experimental method based on a constant-level oil tank ignition source, characterized in that, The method applied to the dual-chamber fire spread experimental apparatus based on a constant-level oil tank fire source according to any one of claims 1 to 9, the method comprising: According to the experimental conditions, the spatial distance between the combustion chamber (1) and the fire-receiving chamber (2) is adjusted to the target distance indicated by the experimental conditions by the spacing adjustment component (8); Combustible materials are arranged in the combustible material arrangement area (16) of the fire-receiving chamber (2); Start the constant liquid level oil tank fire source assembly (3), the fire source in the combustion chamber (1) heats and causes the first glass component (12) to break, the flame overflows outward through the first window opening (10), externally heats the second glass component (15), causes the second glass component (15) to break or fall off, and forms a new ventilation opening at the second window opening (13); Flames and high-temperature flue gas enter the interior of the fire-receiving chamber (2) through a new ventilation opening to heat the combustible material and monitor the thermal response of the combustible material and whether ignition occurs; During the process from the start of the constant liquid level oil tank fire source component (3) to the start of fire spread, parameter data is continuously acquired. The parameter data includes at least image data of the combustion chamber (1) and the fire-receiving chamber (2).

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