Chamber fire-curtain wall interaction experimental device and method based on variable boundaries

Abstract

The present invention provides a chamber fire-curtain wall interaction experimental device and method based on variable boundaries, which belongs to the field of fire safety technology. The device includes a combustion chamber, including multiple wall surfaces; a variable curtain wall structure, including a metal frame, installed on the open part of the wall surface; and a clamping mechanism, suitable for crimping the plate to be tested on the metal frame to form a curtain wall; a temperature measurement system, including a space temperature measurement component, suitable for measuring the chamber temperature data in the combustion chamber, and a surface temperature measurement component, suitable for measuring the surface temperature data of the plate to be tested; an image acquisition system, suitable for acquiring image data of the simulated fire process in the combustion chamber, and image data of the variable curtain wall structure. The present invention can simulate the continuous evolution process of the fire dynamics caused by the rupture and detachment of the curtain wall in a real fire, and provide a real and reliable experimental support for the analysis and mechanism research of the interaction phenomenon between chamber fire and curtain wall.

Description

Technical Field

[0001] The invention relates to the technical field of fire safety, and in particular to a chamber fire-curtain wall interaction experimental device and method based on a variable boundary. Background Art

[0002] Building curtain wall refers to the structure used for enclosure or decoration outside the building, which has the advantages of beautiful appearance, environmental protection and energy saving. Common types of building curtain wall include tempered glass curtain wall, photovoltaic glass curtain wall, etc. Tempered glass curtain wall first came out in the early 20th century and has been widely used around the world.

[0003] However, compared with the traditional reinforced concrete exterior wall plus glass window structure, although the glass (or photovoltaic) curtain wall has the advantages of energy saving, environmental protection and beautiful appearance, it has certain fragility. When subjected to high-intensity or long-term effects of external forces, light, flames and other factors, the structural stability will be destroyed, leading to accidents. In a building fire environment, especially in the early stages of a fire, the ventilation conditions in the building determine the direction of the fire, so the structural stability of the glass (or photovoltaic) curtain wall becomes more important. Once a glass component breaks or even falls off over a large area under the action of heat load, on the one hand, it will cause new ventilation windows to appear on the boundary of the building, accelerating the formation and spread of the facade fire; on the other hand, it will enhance the interaction between the fire and the external environment, pushing the fire in a more violent direction.

[0004] Glass (or photovoltaic) curtain wall buildings have the following interactive process during fires: the curtain wall is structurally damaged by flames or hot smoke, and new ventilation openings are formed on the building facade. On the one hand, external oxygen flows into the room, promoting the development of the fire, so that the flame has a continuous impact on the curtain wall structure that has not yet been damaged, and then new vents are formed; on the other hand, the unburned hot smoke in the room will break through the curtain wall boundary and spread vertically or horizontally under the action of buoyancy or ambient wind, forming external curtain wall fire overflow, extending this continuous interaction to other areas of the building. In the above continuous and complex process, the ventilation openings formed by the sudden change of the curtain wall structure are undoubtedly a boosting factor. The timing and size of the ventilation openings determine the next development direction of the building fire.

[0005] Therefore, experimental observation and model prediction of the above-mentioned complex phenomena are particularly important. However, it is difficult to simulate the mutation process of curtain wall structure in a real fire in the relevant technology, and the measurement and analysis of simulated fire data can hardly meet the expected requirements of building fire prevention and control. Summary of the invention

[0006] In view of this, in order to at least partially solve at least one of the above-mentioned technical problems, the present invention provides a chamber fire-curtain wall interaction experimental device and method based on variable boundaries.

[0007] A chamber fire-curtain wall interaction experimental device based on a variable boundary, the device comprising: a combustion chamber, comprising a plurality of walls, enclosing an internal space to form a simulated fire, wherein one of the plurality of walls has an open portion, a fire source is arranged in the combustion chamber, and is suitable for burning to simulate the fire; a variable curtain wall structure, comprising a metal frame, installed on the open portion of the wall; and a clamp mechanism, installed on the metal frame, suitable for crimping a plate to be tested on the metal frame to form a curtain wall, the curtain wall can be broken or fallen off, so as to serve as a variable boundary of the combustion chamber for the interaction between the fire and the curtain wall; a temperature measurement system, comprising a space temperature measurement component, suitable for measuring chamber temperature data in the combustion chamber, and a surface temperature measurement component, suitable for measuring surface temperature data of the plate to be tested during the interaction process; an image acquisition system, suitable for acquiring image data of the simulated fire process in the combustion chamber, and image data of the variable curtain wall structure; a critical state analysis system, suitable for analyzing the critical state of the simulated fire according to the chamber temperature data, the surface temperature data, and the image data, the critical state comprising: the occurrence of flashover, and the breaking or falling off of the curtain wall.

[0008] A chamber fire-curtain wall interaction experiment method using the above device includes: placing a plate to be tested in a metal frame of a variable curtain wall structure, and abutting the plate to be tested against the metal frame through a clamping mechanism; igniting fuel in a combustion chamber to simulate a fire; during the simulated fire, measuring chamber temperature data in the combustion chamber and surface temperature data of the plate to be tested through a temperature measurement system, and measuring image data of the combustion chamber and the variable curtain wall structure through an image acquisition system; and analyzing the critical state of the simulated fire according to the chamber temperature data, surface temperature data, and image data through a critical state analysis system, wherein the critical state includes: occurrence of flashover and rupture or detachment of the curtain wall.

[0009] Based on the above technical solution, the beneficial effects of the present invention are:

[0010] (1) The present invention combines a combustion chamber with a variable curtain wall structure to form a curtain wall building fire experimental platform, which can complete the simulation and observation of continuous interactive phenomena in curtain wall building fires. Specifically, the variable boundary of the fire-curtain wall interaction is constructed by installing a variable curtain wall structure on the combustion chamber, and the key fire parameters are recorded through a variety of data acquisition systems. The generation and evolution process of interactive phenomena in a building fire environment can be realistically simulated, thereby analyzing the development law of curtain wall building fires that is different from conventional building fires.

[0011] (2) The present invention collects temperature data and image data in the combustion chamber and surface temperature data and image data of the variable curtain wall structure, which is helpful for observing the specific evolution process of the interaction between fire and curtain wall, especially the occurrence of flashover, rupture or detachment of curtain wall, etc. The analysis of critical states is of great significance, which is also the key point and blind spot of current research on building fire safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0013] Figure 1 A schematic structural diagram of a chamber fire-curtain wall interaction experimental device based on a variable boundary according to an embodiment of the present invention is shown;

[0014] Figure 2 A schematic structural diagram of a metal frame according to an embodiment of the present invention is shown;

[0015] Figure 3 A schematic structural diagram of a clamping mechanism according to an embodiment of the present invention is shown;

[0016] Figure 4 A schematic diagram of an infrared camera acquisition component according to an embodiment of the present invention is shown;

[0017] Figure 5 A schematic structural diagram of a mass loss measurement system according to an embodiment of the present invention is shown;

[0018] Figure 6 A schematic flow chart of a chamber fire-curtain wall interaction experimental method based on a variable boundary according to an embodiment of the present invention is shown;

[0019] Figure 7 The broken shapes of the glass curtain wall at the same moment captured by a high-speed camera assembly according to an embodiment of the present invention are shown;

[0020] Figure 8 The broken shapes of the glass curtain wall captured at the same moment by the infrared camera collection component according to the embodiment of the present invention are shown;

[0021] Fig. 9 The distribution of the surface temperature of the plate to be tested at different positions over time according to the embodiment of the present invention is shown;

[0022] Fig.10 The temperature distribution change over time in a chamber at a specific position according to an embodiment of the present invention is shown.

[0023] In the above drawings, the meanings of the reference numerals are as follows:

[0024] I. Combustion chamber;

[0025] 110, wall surface; 111, open portion;

[0026] 120. Fire source;

[0027] II. Variable curtain wall structure;

[0028] 210, metal frame; 211, frame body; 211a, window; 212, first heat insulation mechanism; 213, fixed frame body; 214, second heat insulation mechanism;

[0029] 220, clamp mechanism; 221, fixed seat; 222, pressure head; 222a, first end of pressure head; 222b, second end of pressure head; 223, push rod; 223a, first end of push rod; 223b, second end of push rod; 224, handle; 225, fastener

[0030] III. Temperature measurement system;

[0031] 310. Space temperature measurement component; 311. Thermocouple array; 312. Data transmission module; 313. Calculation and processing module;

[0032] 320. Surface temperature measurement component; 321. Patch type thermocouple

[0033] IV. Image acquisition system;

[0034] 410. High-speed camera assembly;

[0035] 420, infrared camera acquisition component; 421, infrared detector; 422, data synchronization cable; 423, terminal computer;

[0036] V. Mass loss measurement system;

[0037] 510. Analytical balance; 511. Tray;

[0038] 520, support platform;

[0039] 530, support rod;

[0040] VI. Heat release analysis system;

[0041] 610. Smoke collection device;

[0042] 620. Flue gas analysis device;

[0043] VII. Plate to be tested. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0045] Experimental devices related to curtain wall building fire simulation at home and abroad are mainly used to study the thermal response behavior of single curtain wall structures (such as single tempered glass panels) under non-real fires (such as thermal radiation panels in open environments). They cannot support further continuous interaction experiments and have great limitations.

[0046] In view of this, the present invention provides a chamber fire-curtain wall interaction experimental device and method based on variable boundaries, which can simulate the interaction between chamber fire and curtain wall structure under sudden changes in boundary conditions, and configure multiple sets of temperature and image acquisition systems; further, based on the theory of fire dynamics, a set of methods for data measurement and law analysis using this device is provided. By conducting large-scale experiments, scientifically analyzing the mutual influence of fire and curtain wall, and reasonably characterizing the key issue of interaction in fire, the development law of real building fire scenes can be predicted, reducing fire losses and casualties.

[0047] Specifically, according to some embodiments of the present invention, a chamber fire-curtain wall interaction experimental device based on a variable boundary is provided. Figure 1 The structure diagram of the chamber fire-curtain wall interaction experimental device based on variable boundaries according to an embodiment of the present invention is shown. Figure 2 The schematic diagram of the structure of the metal frame of the embodiment of the present invention is shown as follows: Figure 1 and Figure 2 As shown, the chamber fire-curtain wall interaction experimental device of the embodiment of the present invention includes a combustion chamber I, a variable curtain wall structure II, a temperature measurement system III and an image acquisition system IV, wherein:

[0048] The combustion chamber I includes a plurality of walls 110, which enclose an internal space to simulate a fire, wherein one of the plurality of walls has an open portion 111, and a fire source 120 is arranged in the combustion chamber I, which is suitable for burning to simulate a fire; the variable curtain wall structure II includes a metal frame 210, which is installed on the open portion 111 of the wall 110; and a clamp mechanism 220 is installed on the metal frame 210, which is suitable for pressing the plate to be tested VII onto the metal frame 210 to form a curtain wall, and the curtain wall can be broken or fallen off to serve as a variable boundary of the combustion chamber I for the interaction between the fire and the curtain wall; the temperature measurement system III includes a space temperature measurement component 310, which is suitable for measuring the chamber temperature data in the combustion chamber I, and a surface temperature measurement component (not shown in the figure), which is suitable for measuring the surface temperature data of the plate to be tested VII during the interaction process; an image acquisition system IV is suitable for acquiring image data of the simulated fire process in the combustion chamber I, and image data of the variable curtain wall structure II; a critical state analysis system (not shown in the figure), which is suitable for analyzing the critical state of the simulated fire based on the chamber temperature data, surface temperature data, and image data, and the critical state includes: flashover, and curtain wall rupture or shedding.

[0049] According to an embodiment of the present invention, "critical state" means that the temperature in the combustion chamber, heat flow, heat release, curtain wall temperature or curtain wall thermal stress reaches a critical value. Based on this critical state, it can be used to predict the occurrence of curtain wall rupture and flashover, so that engineering means can be used to reduce the fire hazard of curtain wall buildings.

[0050] According to the embodiments of the present invention, "flashover" means that the fire in the chamber suddenly changes from local combustion to combustion of all combustible surfaces. It is a transient process, which includes drastic changes in parameters such as temperature, combustion range, and gas concentration. The judgment basis of flashover may include any of the following: the occurrence of a turning point where the temperature rises sharply; the occurrence of the ceiling temperature exceeding the temperature threshold, such as 600°C; the occurrence of the ground heat radiation exceeding the threshold, such as 20kW / m 2 ; or flames escape from vents or extend along interior ceilings.

[0051] According to an embodiment of the present invention, the present invention adopts a combustion chamber as the main space for simulating a fire, and a fire source is arranged in the chamber. After the fire source is ignited, various parameters or data such as temperature, heat flow, image, etc. can be observed. The variable curtain wall structure is fixed to the open part of the wall surface, which is the main area where the interaction between the fire and the curtain wall occurs. Its rupture or detachment will cause a sudden change in the boundary. The temperature measurement system can be used to measure the temperature field distribution in the space inside the combustion chamber, as well as the surface temperature data of the plate to be tested during the interaction process, so as to analyze the thermal reaction law between the combustion chamber and the curtain wall. The image data of the combustion chamber and the variable curtain wall structure collected by the image acquisition system can be used to analyze the structural micro-change characteristics and thermodynamic parameter characteristics at the interaction moment.

[0052] Therefore, the setting of variable curtain wall structure can simulate the interaction between chamber fire and curtain wall under sudden changes in boundary conditions, which is more in line with the real building fire situation and fire development law. In addition, through a variety of data measurement systems to record the temperature changes and structural micro-changes during the interaction process, the specific evolution process of the interaction between fire and curtain wall can be observed, the critical state can be analyzed and determined, and the relationship between flashover phenomenon and boundary mutation can be analyzed.

[0053] According to an embodiment of the present invention, Figure 1 As shown, the combustion chamber can be a large-sized chamber with an internal space size of 1 to 2 m. For example, the internal space of the combustion chamber is a rectangular parallelepiped, and its side length is 1 to 2 m, which can be 1 m, 1.2 m, 1.4 m, 1.6 m, 1.8 m, 2 m, etc. For example, Figure 1 The combustion chamber shown is 1.8 × 1.2 × 1.2 m 3 Through large-scale experiments, we can more realistically simulate the generation and evolution of interactive phenomena in building fire environments, thereby analyzing the development laws of curtain wall building fires that are different from conventional building fires.

[0054] According to an embodiment of the present invention, the wall 110 of the combustion chamber I is a steel plate, which is connected by sealing welding. The thickness of the steel plate can be 8 to 12 cm to provide the structural strength required for simulating fire. The combustion chamber I can also include a heat insulation board (not shown in the figure), which is laid along the inner wall of the steel plate. Since the heat insulation board has good heat insulation, it can be used to simulate the insulation effect of a real building. Exemplarily, the heat insulation board can be a ceramic fiberboard (the main component is aluminum silicate, and the thermal conductivity coefficient at room temperature is 0.03W / (m·K)), and the thickness can be 4 to 8 cm.

[0055] According to an embodiment of the present invention, Figure 1 As shown, the five walls of the combustion chamber 1 are completely sealed and welded, while one wall is open, that is, the open portion 111 occupies the entire area of ​​the wall 110, and the open portion 111 is, for example, 1.2×1.2 m 2 However, the present invention is not limited thereto, and in different implementations, the open portion 111 may also be located in a partial area of ​​the wall surface.

[0056] According to an embodiment of the present invention, the fire source 120 in the combustion chamber 1 may include a metal oil pan, and the opening size may be, for example, 30 to 50 cm, for example, 30 cm, 35 cm, 40 cm, 45 cm, 50 cm, etc. For example, Figure 1 Shown is an opening size of 40 x 40 cm 2Compared with using combustible gas as fuel, it is necessary to assume that the fire is always in a stable state. The metal oil pan of the present invention can hold liquid or solid fuel, and the simulated fire process is no longer always in a stable state. The measured thermodynamic change law is more consistent with the real building fire.

[0057] According to an embodiment of the present invention, the main body of the variable curtain wall structure II is a metal frame 210, such as Figure 2 As shown, the metal frame 210 may include a frame body 211 and a first heat insulation mechanism 212, wherein: the frame body 211 includes a plurality of windows 211a suitable for installing the plate VII to be tested, and the first heat insulation mechanism 212 is sandwiched between the plate VII to be tested and the frame body 211, which can achieve heat insulation and sealing effects. The design of multiple windows 211a of the metal frame can better simulate the building curtain wall structure, and the number of windows can be, for example, Figure 1 and Figure 2 As shown in the figure, there are 4 or 9 windows, but it is not limited thereto. Adjustment of the number of windows can achieve different boundary mutation situations. For example, Figure 2 The first thermal insulation mechanism 212 shown may be thermal insulation wool, but is not limited thereto.

[0058] According to an embodiment of the present invention, Figure 1 and Figure 2 As shown, further optionally, the metal frame 210 may also include a fixed frame 213 and a second heat insulation mechanism 214, wherein: the fixed frame 213 is arranged on the side of the plate to be tested VII away from the frame body 211, and the second heat insulation mechanism 214 is clamped between the plate to be tested VII and the fixed frame 213, wherein pressure is applied to the fixed frame 213 by the clamp mechanism 220 to abut the plate to be tested VII against the frame body 211. Such an arrangement allows the plate to be tested VII to be subjected to uniform force and can be more tightly installed on the metal frame 210 to form a curtain wall. The second heat insulation mechanism 214 is similar to the first heat insulation mechanism 212 and will not be described in detail here.

[0059] According to an embodiment of the present invention, the variable feature of the variable curtain wall structure of the present invention is that: during the experiment, the plate to be tested can spontaneously break and fall off due to the thermal effect, thereby simulating the scene of the building curtain wall being heated and broken and falling off in a real fire; or it can also be artificially fallen off by manually operating the clamp mechanism, thereby simulating the scene of firefighters rescuing and demolishing in a real fire. In different stages of fire development, including but not limited to the above two real scenarios, there is a process in which glass falls off to form new ventilation openings, that is, the sudden change of boundary conditions is an inevitable objective fact; and its interaction with the fire also has very important scientific research and engineering value. Therefore, through the variable curtain wall structure of the device of the present invention, the above-mentioned scenario can be simply and intuitively restored, which is of great significance for solving the scientific problem of boundary mutations and their interactive effects in chamber fires, as well as guiding fire engineering design and firefighting and rescue strategies.

[0060] More specifically, the clamp mechanism 220 is adapted to switch between a locked state and an unlocked state, wherein the plate VII to be tested is pressed against the metal frame 210 in the locked state, and the plate VII to be tested is dropped from the metal frame 210 in the unlocked state. Thus, the above-mentioned process of manually dropping the plate VII to be tested can be realized conveniently and quickly.

[0061] According to an embodiment of the present invention, Figure 3 FIG. 4 is a schematic diagram showing the structure of the clamp mechanism according to an embodiment of the present invention. Figure 3 As shown, the clamp mechanism 220 includes a fixing seat 221, a pressing head 222, a push rod 223 and a handle 224, wherein:

[0062] The fixing seat 221 is installed on the metal frame 210, more specifically, on the frame body 211; the bottom of the first end 222a of the pressing head is pivoted to the fixing seat 221, and the second end 222b of the pressing head is provided with a fastener 225, and the fastener 225 is suitable for abutting the plate VII to be tested against the metal frame 210; the first end 223a of the push rod is pivoted to the top of the first end 222a of the pressing head, and the second end 223b of the push rod is pivoted to the fixing seat 221 through the connecting rod 226; the handle 224 is fixedly connected to the second end 223b of the push rod, wherein the fixing seat 221, the pressing head 222, the push rod 223 and the connecting rod 226 constitute a four-bar linkage, and the handle 224 controls the movement of the push rod 223, driving the pressing head 222 to move between the first position and the second position, so as to switch between the locked state and the unlocked state. Therefore, by using the clamp mechanism 220 to control the plate VII to be tested to be pressed onto the metal frame 210, or to fall off from the metal frame 210, a sudden change of the boundary condition can be easily achieved.

[0063] Further optionally, the fastener 225 can be an adjustable bolt. For plates of different thicknesses or materials, the nut position of the adjustable bolt can be adjusted to fix the plate VII to be tested in the frame with an equal load, thereby maintaining the consistency of the experimental environment under different working conditions.

[0064] According to an embodiment of the present invention, further, the variable curtain wall structure II is also variable in that: the material type of the plate to be tested VII can be easily switched, such as tempered glass, float glass, photovoltaic glass or rock board, etc.; the size (length × width × thickness) of the plate to be tested VII can be changed, such as 660 × 630 × 6 mm 3 , 300 × 300 × 10 mm 3 etc.; the installation quantity of the panel VII to be tested can be variable, such as fully enclosed installation (simulating closed windows) and partially open installation (simulating open windows).

[0065] Furthermore, the material of the plate to be tested is preferably light-transmissive, so that it can be used as an observation window in the experiment to facilitate recording and analysis of the development and interaction of the fire in the combustion chamber.

[0066] According to an embodiment of the present invention, Figure 2 As shown, the chamber fire-curtain wall interaction experimental device can also include a heat flux measurement system, which includes a heat flux meter installed in the hole of the metal frame 210 and is suitable for measuring the heat flux distribution during the interaction process on the inner surface of the curtain wall.

[0067] According to an embodiment of the present invention, Figure 1 As shown, the spatial temperature measurement component 310 includes a thermocouple array 311, a data transmission module 312 and a calculation and processing module 313, wherein: the thermocouple array 311 is arranged inside the combustion chamber I, and is suitable for measuring the temperature data in the chamber; the data transmission module 312 is suitable for transmitting the temperature data in the chamber collected by the thermocouple array 311; and the calculation and processing module 313 is suitable for processing the temperature data in the chamber transmitted by the data transmission module 312.

[0068] Furthermore, the thermocouple array 311 inside the combustion chamber I may include: a plurality of thermocouple brackets, which are horizontally distributed and arranged on the wall of the combustion chamber I and around the metal oil pool 120; and a plurality of probe-type thermocouples, which are installed on each thermocouple bracket. Exemplarily, 7 thermocouple brackets are arranged in the combustion chamber I, which are respectively located on the side wall of the chamber and behind the metal oil pool. In the vertical direction, each thermocouple bracket is installed with 6 probe-type thermocouples with a diameter of 1 mm from top to bottom; a total of 42 thermocouples are distributed in the three-dimensional space of the chamber, which are used to measure the spatial temperature changes in the interactive process of fire development in real time.

[0069] According to an embodiment of the present invention, Figure 2 As shown, the surface temperature measurement component 320 may include a patch thermocouple 321 and a multi-channel data acquisition instrument (not shown in the figure), wherein: the patch thermocouple 321 is attached to multiple areas on the surface of the plate VII to be tested, and is suitable for measuring surface temperature data; the multi-channel data acquisition instrument is suitable for collecting surface temperature data measured by the patch thermocouple 321. Furthermore, the setting area of ​​the patch thermocouple 321 may include the exposed area and the shielded area of ​​the plate VII to be tested, and is suitable for recording the temperature distribution and changes of different areas on the curtain wall surface in a fire.

[0070] According to an embodiment of the present invention, the image acquisition system IV includes: a high-speed camera assembly 410, which is suitable for collecting flame image data of a simulated fire process in the combustion chamber I, and structural image data of a variable curtain wall structure. Further, the high-speed camera assembly may include two high-speed cameras and a stable bracket for mounting the high-speed cameras, respectively shooting at the wall surface of the combustion chamber I and the variable curtain wall structure, and recording the changes in the flame in the combustion chamber I and the curtain wall overflow flame. Here, "high-speed camera assembly" or "high-speed camera" refers to a camera assembly or device that can capture images at a speed of at least 1000 to 10000 frames per second.

[0071] According to an embodiment of the present invention, the image acquisition system IV further comprises an infrared camera acquisition component 420, which is adapted to acquire infrared spectrum data of the outer surface of the variable curtain wall structure II to determine the temperature data of the outer surface of the plate VII to be tested.

[0072] Further, Figure 4 A schematic diagram of an infrared camera acquisition component according to an embodiment of the present invention is shown as follows Figure 4 As shown, the infrared camera acquisition component 420 may include an infrared detector 421, a data synchronization cable 422, and a terminal computer 423. For example, the model of the infrared detector 421 may be FLIR A655sc, which can detect a wavelength range of [7.5, 14] μm, a maximum frame rate of 200 Hz, and a detectable temperature range of [-40, 650] °C; the data synchronization cable 421 may be connected to the gigabit interface of the infrared detector 421 to achieve real-time transmission of images to the terminal computer 423.

[0073] The high-speed camera assembly and infrared camera acquisition assembly can be used to observe the specific evolution process of the interaction between fire and curtain wall, especially for the analysis of critical states such as the occurrence of flashover and the rupture of curtain wall.

[0074] According to an embodiment of the present invention, according to the Stephen-Boltzmann law in thermodynamics, any object radiates energy into space all the time. For the flame in the combustion chamber I, the wavelength range of the infrared radiation is [2.5,3]∪[4.4,4.6]μm; and for tempered glass, it has a higher reflectivity for radiation with a wavelength greater than 1.2 μm. Therefore, most of the infrared radiation generated by the flame inside the combustion chamber I will be reflected by the inner surface of the test plate VII made of tempered glass, and cannot penetrate the test plate VII to reach the outside of the chamber. Then, the infrared detector 421 can just collect the infrared emitted from the outer surface of the test plate. Using this characteristic, the infrared temperature field of the outer surface of the simulated glass (or photovoltaic) curtain wall can be cleverly obtained, so as to analyze the change law of the curtain wall under the action of fire.

[0075] According to an embodiment of the present invention, the critical state analysis system is suitable for determining at least one of the curtain wall rupture morphology, curtain wall surface temperature distribution, and combustion field temperature distribution related to the critical state based on the chamber temperature data, surface temperature data, and image data. At least part of the functions of the critical state analysis system can be implemented with the aid of a properly programmed computer. It can be combined with at least part of the functions of other systems such as a temperature measurement system, an image acquisition system, a mass loss measurement system, and / or a heat release analysis system, and implemented in one system.

[0076] According to an embodiment of the present invention, the chamber fire-curtain wall interaction experimental device may also include a mass loss measurement system V, which is suitable for measuring the mass change of the fuel in the metal oil pan. It may include an analytical balance 510 and a support platform 520, wherein: the analytical balance 510 includes a tray 511; the support platform 520 is suitable for placing the metal oil pan, and the support platform 520 is connected to the tray 511 through the bottom of the combustion chamber V through a support rod 530. Exemplarily, the model of the analytical balance 510 may be Sartorius MSE70200S, which can be connected to a computing and processing device. Through the setting of the support platform 520, the fuel mass change can be measured on the basis of a large-scale experiment, while protecting the analytical balance from damage caused by the simulated fire.

[0077] According to an embodiment of the present invention, the chamber fire-curtain wall interaction experimental device may also include a heat release analysis system VI, which is a large-scale device for calculating the fire source power based on the oxygen consumption method principle. Figure 1As shown, it may include a smoke collecting device 610 and a smoke analyzing device 620, wherein: the smoke collecting device 610 is suitable for collecting smoke generated in the combustion chamber I; the smoke analyzing device 620 is suitable for measuring the smoke collected by the smoke collecting device 610 to determine the heat release parameters. The heat release parameters may include parameters such as the instantaneous heat release rate and the total heat release calculated according to the oxygen consumption method, which can reflect the impact of the combustion of the combustible component to be tested in the fire on the fire, and accurately and quantitatively determine the fire hazard.

[0078] Furthermore, the smoke collection device 610 includes a conical smoke hood, a smoke delivery pipeline and a fan. The conical smoke hood is arranged above the combustion chamber I, more specifically, above the open portion of the wall 110, and its diameter may be, for example, 5m×5m. The fan is used to transmit the smoke from the conical smoke hood to the smoke collection device 610. The smoke analysis device includes a thermal parameter measurement device, a gas composition analyzer, a smoke density measurement instrument, an auxiliary device, etc.

[0079] According to some embodiments of the present invention, a chamber fire-curtain wall interaction test method using the apparatus as described above is also provided. Figure 6 FIG. 4 is a flow chart showing a chamber fire-curtain wall interaction experimental method based on a variable boundary according to an embodiment of the present invention. Figure 6 Combination Figure 1 As shown, the method of the embodiment of the present invention includes operations S101 to S104:

[0080] In operation S101, the plate VII to be tested is placed in the metal frame 210 of the variable curtain wall structure II, and the plate VII to be tested is abutted against the metal frame 210 by the clamp mechanism 220;

[0081] In operation S102, the fuel in the combustion chamber I is ignited to simulate a fire;

[0082] In operation S103, during the simulated fire process, the temperature data in the combustion chamber I and the surface temperature data of the plate to be tested VII are measured by the temperature measurement system III, and the image data of the interior of the combustion chamber I and the variable curtain wall structure II are measured by the image acquisition system;

[0083] In operation S104, a critical state analysis system analyzes the critical state of the simulated fire according to the chamber temperature data, the surface temperature data, and the image data. The critical state includes: flashover and curtain wall rupture or fall-off.

[0084] According to an embodiment of the present invention, the theoretical basis involved in the above experimental method is as follows:

[0085] On the one hand, under the heat radiation and heat convection of flame and smoke, heat is transferred from the combustion chamber I to the curtain wall, causing the plate to be heated and cracked and fall off. This process can be expressed as ,in , , Respectively represent specific heat, density and thickness of the plate to be tested, is the convective heat transfer coefficient, is the Stefan-Boltzmann constant, is the glass surface emissivity, , are the inner surface temperature of the plate to be tested and the temperature in the chamber, respectively. Therefore, based on the above theory, the radiation heat flux and the convection heat flux can be calculated by measuring the inner surface temperature of the plate to be tested and the temperature in the chamber, and the proportion of the radiation heat flux and the convection heat flux in the total heat flux can be obtained.

[0086] Furthermore, by using the device of the present invention to carry out experiments and measure the temperature inside the chamber and the inner surface temperature of the plate to be tested, the energy accumulation of the curtain wall structure under the heat of the fire can be obtained, providing real and reliable data support for the scientific analysis of the fire-curtain wall interaction.

[0087] On the other hand, from a microscopic point of view, the cracking of the plate under test is due to its thermal stress exceeding the strength limit. Thermal stress can be expressed as To calculate, where E is the elastic modulus, is the linear expansion coefficient, is the temperature rise; , is a function of strain and temperature rise, and can be calculated as follows When there is When the rupture occurs, For ultimate strength.

[0088] Furthermore, by using the device of the present invention to carry out experiments and measure the strain and temperature rise of the plate to be tested, the thermodynamic conditions for the generation of cracks and the occurrence of shedding can be analyzed based on the fracture criterion; further, the heat transfer formula mentioned above is coupled with the thermal stress formula to establish a multi-parameter thermal fracture analysis prediction model. Furthermore, based on the high-definition, high-frame image data recorded by the high-speed camera assembly, the accuracy of the established prediction model is verified by image recognition technology, and the measurement error caused by the equipment is corrected. Finally, the established model is applied to engineering practice using numerical simulation methods.

[0089] According to an embodiment of the present invention, in order to facilitate understanding of the critical state analysis process in operation S104, illustratively, as follows Figure 7 and Figure 8The figure shows the fracture morphology of the glass curtain wall at the same moment, which was taken by the high-speed camera assembly and the infrared camera assembly. The image measured by the high-speed camera assembly can clearly show the location where the crack first occurred and the extension direction, and the image measured by the infrared camera assembly can show the temperature field distribution on the glass surface at the critical moment before the fracture.

[0090] According to the measured surface temperature data of the plate to be tested, Calculate the temperature difference of the glass in all directions along the surface, T e is the exposure zone temperature, T s is the temperature of the shielding area. Fig. 9 As shown in the figure, the temperature difference between the center point of the curtain wall (i.e., temperature measuring point TC1) and the temperature measuring points in the shielded area in four directions (i.e., temperature measuring points TC5-TC8) can be calculated through the experimental measurement of the surface temperature of the glass curtain wall. The dotted line indicates the state before the glass breaks (critical state). It can be seen that the maximum temperature difference before the breakage occurs in the direction of the temperature measuring points TC1-TC7, with a value of about 250°C. This result has a certain reference value for the fire protection engineering design of glass curtain wall buildings. For example, the area that is most obviously heated and may break first can be judged according to the size of the temperature difference.

[0091] Based on the measured temperature data in the chamber, for example Fig.10 The temperature change curves at different points on the horizontal plane 10 cm from the ceiling are shown. The temperature distribution of the combustion field during the development of the fire can be obtained through the temperature measurement system in the chamber. By combining the critical state of the curtain wall, the flashover stage and other key nodes for analysis, the interaction between the fire and the curtain wall can be further studied and described. Furthermore, based on the measured temperature data in the chamber, the heat transfer between the chamber and the curtain wall is calculated according to the formula, and the relationship between the flashover phenomenon of the chamber fire and the boundary mutation is analyzed using the flashover criterion.

[0092] According to an embodiment of the present invention, further, the method of the present invention may also include: analyzing the fracture mechanism based on the measured micro-change characteristics of the plate to be tested at the moment of boundary mutation and the temperature distribution on the surface of the plate to be tested before and after the boundary mutation, combined with thermodynamic parameters such as thermal stress.

[0093] According to an embodiment of the present invention, the method of the present invention may further include measuring the inner surface heat flux density of the plate to be tested, including the total heat flux and radiation heat flow , combined with gas composition analysis, the direct cause of the glass panel's thermal cracking was inferred.

[0094] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A chamber fire-curtain wall interaction experimental device based on variable boundaries, characterized in that: The device comprises: A combustion chamber, comprising a plurality of walls, enclosing an internal space to form a simulated fire, wherein one of the plurality of walls has an open portion, and a fire source is disposed in the combustion chamber, suitable for combustion to simulate a fire; A variable curtain wall structure, comprising a metal frame mounted on the open portion of the wall surface; and a clamp mechanism mounted on the metal frame, adapted to crimp the plate to be tested onto the metal frame to form a curtain wall, wherein the curtain wall can be broken or detached to serve as a variable boundary of the combustion chamber for interaction between the fire and the curtain wall; The temperature measurement system includes a space temperature measurement component, which is suitable for measuring the chamber temperature data in the combustion chamber, and a surface temperature measurement component, which is suitable for measuring the surface temperature data of the plate to be measured during the interaction process; An image acquisition system, adapted to acquire image data of a simulated fire process in a combustion chamber, and image data of the variable curtain wall structure; The critical state analysis system is suitable for analyzing the critical state of the simulated fire according to the chamber temperature data, surface temperature data and image data, wherein the critical state includes: flashover, and curtain wall rupture or shedding.

2. The chamber fire-curtain wall interaction experimental device according to claim 1, characterized in that: The metal frame comprises: A frame body, comprising a plurality of windows suitable for mounting the panels to be tested; and The first heat insulation mechanism is sandwiched between the plate to be tested and the frame body.

3. The chamber fire-curtain wall interaction experimental device according to claim 1, characterized in that: The clamp mechanism is suitable for switching between a locked state and an unlocked state, wherein the plate to be tested is pressed onto the metal frame in the locked state, and the plate to be tested is dropped from the metal frame in the unlocked state.

4. The chamber fire-curtain wall interaction experimental device according to claim 3, characterized in that: The clamping mechanism comprises: A fixing seat, mounted on the metal frame; A pressure head, wherein the bottom of the first end of the pressure head is pivotally connected to the fixing seat, and a fastener is provided at the second end of the pressure head, and the fastener is suitable for abutting the plate to be tested against the metal frame; A push rod, a first end of which is pivotally connected to the top of the first end of the pressure head, and a second end of which is pivotally connected to the fixing seat through a connecting rod; and A handle is fixedly connected to the second end of the push rod, wherein the handle controls the movement of the push rod to drive the pressure head to move between the first position and the second position to switch between the locked state and the unlocked state.

5. The chamber fire-curtain wall interaction experimental device according to claim 1, characterized in that: The wall of the combustion chamber is a steel plate connected by sealing welding; The combustion chamber also includes a heat insulation plate, which is laid along the inner wall of the steel plate.

6. The chamber fire-curtain wall interaction experimental device according to claim 1, characterized in that: The space temperature measurement component comprises: A thermocouple array, the array is arranged inside the combustion chamber and is suitable for measuring temperature data inside the chamber; A data transmission module, adapted to transmit the chamber temperature data collected by the thermocouple array; and The calculation and processing module is adapted to process the chamber temperature data transmitted by the data transmission module.

7. The chamber fire-curtain wall interaction experimental device according to claim 1, characterized in that: The surface temperature measurement assembly comprises: Patch-type thermocouples are attached to multiple areas on the surface of the plate to be tested and are suitable for measuring the surface temperature data; and A multi-channel data acquisition instrument is suitable for acquiring the surface temperature data measured by the patch thermocouple.

8. The chamber fire-curtain wall interaction experimental device according to claim 1, characterized in that: The image acquisition system comprises: The high-speed camera assembly is suitable for collecting flame image data of the simulated fire process in the combustion chamber and structural image data of the variable curtain wall structure.

9. The chamber fire-curtain wall interaction experimental device according to claim 1, characterized in that: The plate to be tested is tempered glass or photovoltaic glass; the image acquisition system also includes: The infrared camera acquisition component is suitable for acquiring infrared spectrum data of the outer surface of the variable curtain wall structure to determine the temperature data of the outer surface of the plate to be tested.

10. The chamber fire-curtain wall interaction experimental device according to claim 1, characterized in that: The fire source includes a metal oil pan suitable for placing fuel that causes fire; The apparatus also includes a mass loss measurement system, including: Analytical balance, including pan; and The supporting platform is suitable for placing the metal oil pan, and the supporting platform is connected to the tray through a supporting rod passing through the bottom of the combustion chamber.

11. The chamber fire-curtain wall interaction experimental device according to claim 1, characterized in that: The device also includes a heat release analysis system, which includes: a smoke collecting device, adapted to collect smoke generated in the combustion chamber; and The smoke analyzing device is suitable for measuring the smoke collected by the smoke collecting device to determine heat release parameters.

12. A chamber fire-curtain wall interaction test method using the chamber fire-curtain wall interaction test device based on variable boundaries as claimed in any one of claims 1 to 11, characterized in that: include: Placing the plate to be tested in a metal frame of a variable curtain wall structure, and abutting the plate to be tested against the metal frame through a clamping mechanism; igniting fuel in the combustion chamber to simulate a fire; During the simulated fire process, the temperature data in the combustion chamber and the surface temperature data of the plate to be tested are measured by the temperature measurement system, and the image data of the interior of the combustion chamber and the variable curtain wall structure are measured by the image acquisition system; The critical state of the simulated fire is analyzed by a critical state analysis system according to the chamber temperature data, the surface temperature data and the image data. The critical state includes: flashover and curtain wall rupture or shedding.

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