Forest-town junction area building external fire test device and test method

Abstract

The invention provides a forest-town junction area building external fire test device and test method.The forest-town junction area building external fire test device comprises a combustion system, an air blowing system, an ignition system, a water collection system, a measurement system and a data acquisition system, and the air blowing system, the ignition system, the water collection system, the measurement system and the data acquisition system are arranged on one side of the combustion system; the ignition system is used for ensuring ignition conditions, the water collecting system is located below the combustion system and used for collecting water, and the measuring system is used for measuring temperature, heat radiation and size; the fire extinguishing system is further installed on the combustion system and used for testing the fire extinguishing efficiency, and the data acquisition system is in signal connection with the air blowing system, the fire extinguishing system and the measuring system. According to the forest-town junction area building external fire test device and test method, spraying cooling can be carried out on the exterior of a building facility, it is ensured that combustible materials related to the building external facility can not be ignited within a certain time, and the purpose of cooling protection on the fire is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of fire testing, and in particular relates to an external fire testing device for buildings in a forest-town boundary area. Background Art

[0002] Forest fires can ignite buildings in a variety of ways. At close range, exposed combustible materials may ignite through radiation, convection, or direct flame contact. At long distances, burning particles break off from larger objects involved in the fire and are blown or thrown to new locations, where they can ignite localized fires in the form of flying fires. Flying fires may ignite vulnerable parts of the exterior of a building and may penetrate into interior spaces through vulnerable openings in the building envelope. Therefore, through theoretical analysis of fixed fire extinguishing, the design scheme and key parameters of fixed fire extinguishing technology were preliminarily determined; a fixed fire extinguishing test model was constructed, and experimental research was conducted to test the effectiveness of fixed fire extinguishing technology in extinguishing fires on the exterior of buildings and facilities. Summary of the Invention

[0003] In view of this, the present invention aims to propose an external fire test device for buildings at the forest-town interface area, so as to optimize the structure and engineering application parameters of the sprinkler heads in the automatic sprinkler fire extinguishing system at the forest-town interface area, so as to achieve the best balance between fire prevention and extinguishing effect and the lowest engineering application cost.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A fire test device for buildings on the border between forest and town.

[0006] It includes a combustion system and an air blowing system, ignition system, water collection system, measurement system and data acquisition system installed on one side of the combustion system. The combustion system is the overall building structure. The air blowing system is used to measure the impact of wind speeds at different angles on fires outside the building. The ignition system is used to ensure the standardization of ignition conditions. The water collection system is located below the combustion system and is used to collect water. The measurement system is used to measure the temperature, thermal radiation and flame size during the combustion process of the combustion system. The combustion system is also equipped with a fire extinguishing system, which is used to test the fire extinguishing effectiveness. The data acquisition system is connected to the air blowing system, fire extinguishing system and measurement system respectively.

[0007] Furthermore, a universal wheel capable of rotating 360° is provided at the bottom of the blowing system.

[0008] Furthermore, the combustion system includes a main body and a roof and square tubes installed above it. The main body and the roof are welded from galvanized square tubes. The overall dimensions of the main body are 9m high, 4.8m long, and 5m wide. The height of each floor is 3m. The side wall facade of the main body can be removably installed with cement boards and insulation materials.

[0009] Furthermore, the ignition system includes a natural gas source and a main pipeline installed above it. The main pipeline is provided with several branch pipelines, and a valve is installed on each pipeline, so that the ignition system can realize different single-point ignition and multi-point simultaneous ignition, ensuring the standardization of ignition conditions.

[0010] Furthermore, the fire extinguishing system includes a top sprinkler pipe, a No. 1 sprinkler head, a No. 2 sprinkler head, a water tank and a water pump group. A top sprinkler pipe is installed above the main body, and a number of No. 1 sprinkler heads with adjustable angles are provided on the top sprinkler pipe. Several sprinkler pipes are installed on the exterior wall of the main body at equal intervals from top to bottom. Each sprinkler pipe is provided with a number of No. 2 sprinkler heads with adjustable angles and retractable lengths. The top sprinkler pipe and the sprinkler pipe are both connected to the water tank via a water pump group.

[0011] Furthermore, the water collection system is a water collection box and an electronic balance arranged below it, and the data of the electronic balance can be transmitted to the data acquisition system.

[0012] Furthermore, the measurement system includes a height measuring scale, thermocouples, a heat flux meter, a camera, and an infrared thermal imager. Several thermocouple groups, each containing several thermocouples, are evenly spaced from top to bottom on the exterior facade of the main structure. A height measuring scale, a heat flux meter, a camera, and an infrared thermal imager are also installed on the exterior of the main structure. The height measuring scale is used to measure the height of the burning flames and the height of the building facade after the fire is extinguished. The heat flux meter is used to test thermal radiation, the camera is used to collect visible light video data, and the infrared thermal imager is used to measure the temperature field of the fire scene and track hot spots to display the temperature changes of the building during the experiment. The heat flux meter, camera, infrared thermal imager, water pump group, electronic balance, and thermocouple signals are all connected to the data acquisition system.

[0013] Furthermore, the data acquisition system is a computer or an industrial computer.

[0014] Furthermore, five thermocouple temperature measuring points are respectively set up on the side wall facade of the main body at heights of 3m, 6m and 9m from the ground, with a distance of 1.2m between adjacent temperature measuring points, and thermocouples are installed on the thermocouple temperature measuring points.

[0015] Furthermore, an infrared thermal imager is placed 12 meters away from the central axis of the 4.8-meter-long side outer wall of the main body. The infrared thermal imager is 1.0 meters above the ground and images the entire experimental building target in real time in the form of a "surface". The image color and hot spot tracking displayed on the screen show the temperature changes of the building during the experiment.

[0016] Furthermore, an upright nozzle is installed in the center of the top spray pipeline, and drooping nozzles are installed at both ends, and the distance between two adjacent nozzles can be adjusted.

[0017] Furthermore, sprinkler pipes are set up on the facade of the main body at 3m, 6m and 9m from the ground, and the top sprinkler pipe is set parallel to the ridge direction.

[0018] Furthermore, the camera is set at 6 meters in the direction of the horizontal central axis of the vertical main facade and 1.2 meters above the ground. Compared with the existing technology, the forest-town boundary building exterior fire test device of the present invention has the following advantages:

[0019] (1) The forest-town boundary building exterior fire test device described in the present invention is applied to buildings at the forest-town boundary. When a fire occurs at the forest-town boundary, the exterior of the building facilities can be sprayed for cooling to ensure that the combustible materials related to the building exterior facilities will not be ignited within a certain period of time, thereby achieving the purpose of cooling and protecting against fire.

[0020] (2) The forest-town boundary building external fire test device described in the present invention is applied to buildings at the forest-town boundary. When the boundary fire has spread to the external facilities of the building, the early rapid response performance of the test device is used to implement spraying fire suppression to achieve rapid disposal of early fires or small-scale fires in the external facilities of the building.

[0021] Another object of the present invention is to propose a method for testing external fires of buildings at the interface between forests and towns, so as to optimize the structure and engineering application parameters of the sprinkler heads in the automatic sprinkler fire extinguishing system at the interface between forests and towns, thereby achieving the best balance between fire prevention and extinguishing effects and the lowest engineering application costs.

[0022] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0023] A method for testing exterior fire of buildings at the interface of forest and town, and a device for testing exterior fire of buildings at the interface of forest and town, comprising the following steps:

[0024] S1. Build and debug the test equipment to ensure that the equipment reaches the predetermined state; conduct a cold spray test before conducting the fire extinguishing test to ensure that the fire extinguishing system can effectively cover the combustion area of ​​the ignition system. If it cannot cover the combustion area, the fire extinguishing system needs to be adjusted until it meets the requirements;

[0025] S2. Install and debug the backup fire extinguishing facilities for use. If the fire extinguishing system fails to extinguish the fire after being activated for a long period of time, immediately activate the backup fire extinguishing facilities to extinguish the fire. This fire extinguishing test is considered a failure. The test should be repeated after changing the fire extinguishing system supply intensity or other test conditions.

[0026] S3. Start the ignition system according to the predetermined plan, using different single-point ignition or multi-point simultaneous ignition according to the actual test situation. When the combustion system is burning, the measurement system will collect the burning flame height, the fire height of the building facade after the fire is extinguished, thermal radiation, visible light video data, the temperature field of the fire scene, and hot spot tracking to show the temperature changes of the building during the experiment and transmit them to the data acquisition system in real time;

[0027] S4. When the fire burns to the set position, the data acquisition system controls the water pump group according to the real-time data obtained, so that the sprinklers of the fire extinguishing system spray water until the fire is completely extinguished;

[0028] S5. The data acquisition system analyzes the data of the entire test process and gives the test results. After the test is completed, the test site is processed and prepared for the next test.

[0029] The advantages of the forest-town boundary building external fire test method and the above-mentioned forest-town boundary building external fire test device over the existing technology are the same, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0031] Figure 1 This is a schematic diagram of a fire test device for buildings located at the forest-town boundary according to an embodiment of the present invention;

[0032] Figure 2 This is the thermocouple curve at a height of 3m on the facade in the blank experiment described in the embodiment of the present invention;

[0033] Figure 3 This is the thermocouple curve at a height of 6m on the facade in the blank experiment described in the embodiment of the present invention;

[0034] Figure 4 This is the thermocouple curve at a height of 9m on the facade in the blank experiment described in the embodiment of the present invention;

[0035] Figure 5 This is the thermocouple curve at a height of 9 meters from the ground and 1 meter away from the outer wall in the blank experiment described in the embodiment of the present invention;

[0036] Figure 6 This is the thermocouple curve at 1 m from the ground and 1 m from the facade in the blank experiment described in the embodiment of the present invention;

[0037] Figure 7 This is the thermocouple curve at a distance of 2 m from the ground and 1 m from the facade in the blank experiment described in the embodiment of the present invention;

[0038] Figure 8 The heat flow meter curves of 4# to 6# in the blank experiment described in the embodiment of the present invention;

[0039] Figure 9 The temperature curve of the fire extinguishing experiment process of the building facade according to the embodiment of the present invention;

[0040] Figure 10 This is a thermal radiation curve of a fire extinguishing experiment on a building facade according to an embodiment of the present invention;

[0041] Figure 11 This is an infrared thermal imaging image of a building roof fire extinguishing experiment according to an embodiment of the present invention;

[0042] Figure 12 This is an infrared thermal imaging image of a fire extinguishing experiment of a stack fire outside a building described in an embodiment of the present invention.

[0043] Description of reference numerals:

[0044] 1-Main body; 2-Roof; 3-Square tube; 4-Top sprinkler pipe; 5-Nozzle No. 1; 6-Height measuring ruler; 7-Thermocouple; 8-Nozzle No. 2; 9-Water collection system; 10-Heat flow meter; 11-Camera; 12-Blowing system; 13-Infrared thermal imager; 14-Ignition system; 15-Data acquisition system; 16-Water tank; 17-Water pump group. DETAILED DESCRIPTION

[0045] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other.

[0046] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0047] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0048] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0049] A fire test device for buildings in forest-town boundary area, such as Figures 1 to 12 As shown, it includes a combustion system and an air blowing system, an ignition system water collection system, a measurement system and a data acquisition system arranged on one side thereof. The combustion system is the overall building structure. The air blowing system is used to measure the impact of wind speeds at different angles on fires outside the building. The ignition system is used to ensure the standardization of ignition conditions. The water collection system is located below the combustion system and is used to collect water. The measurement system is used to measure the temperature, thermal radiation and size of the combustion system during the combustion process. The combustion system is also equipped with a fire extinguishing system, which is used to test the fire extinguishing effectiveness. The data acquisition system is respectively connected to the air blowing system, the fire extinguishing system and the measurement system for processing and analyzing the above data.

[0050] A universal wheel capable of rotating 360° is provided at the bottom of the blowing system. Preferably, the blowing system is a blower.

[0051] The combustion system includes a main body 1, a roof 2, and a square tube 3. The fire extinguishing system 14 includes a top sprinkler pipe 4, a No. 1 nozzle 5, a No. 2 nozzle 8, a water tank 16, and a water pump group 17. The measurement system includes a height measuring ruler 6, a thermocouple 7, a heat flow meter 10, a camera 11, and an infrared thermal imager 13. The roof 2 is installed above the main body 1, and a top sprinkler pipe 4 is installed on the roof 2. The top sprinkler pipe 4 is provided with a number of No. 1 nozzles 5 with adjustable angles and spacings. Several thermocouple groups and several sprinkler pipes are installed at equal intervals from top to bottom on the exterior facade of the main body 1. Each sprinkler pipe is provided with a There are several adjustable and retractable No. 2 nozzles 8. Each thermocouple group includes several thermocouples 7. The top spray line 4 and the spray line are connected to the water tank 16 via a water pump group 17. The exterior of the main body 1 is also equipped with a height gauge 6, a calorimeter 10, a camera 11, an infrared thermal imager 13, an ignition system 14, and a water collection system 9. The calorimeter 10 is used to measure the thermal radiation of the fire, the camera 11 is used to collect visible light video data, and the infrared thermal imager 13 is used to display the temperature changes of the building during the experiment through the image color and hot spot tracking displayed on the screen. The ignition system 14 is used for ignition. The calorimeter 10, camera 11, infrared thermal imager 13, water pump group 17, and thermocouples 7 are all connected to the data acquisition system 15. The ventilation system 12 is a fan with adjustable wind speed and direction. The height gauge 6 is used to measure the end point of combustion on the exterior of the main body 1 after the fire is extinguished.

[0052] The main structure 1 measures 9 meters high, 4.8 meters long, and 5 meters wide, with each floor 3 meters high. Both the main structure 1 and the roof 2 are welded from galvanized square tubes 3. The main structure is welded using 60*100mm square steel, while the crossbeams and diagonal columns are welded using 60*60mm square steel. Removable cement board and B2-grade exterior wall insulation are installed on the 4.8m-long side of the exterior wall. The cement board and insulation can be clipped onto the exterior facade. 10mm-thick cement board and 50mm-thick B2-grade exterior wall insulation board are secured to the front of the main structure using dovetail screws and metal clips. The roof is welded using 60*100mm and 60*60mm square steel. Fireproofing panels are installed above the platform roof 2.

[0053] Water sprinkler pipes are installed on the building facade and roof. Sprinkler pipes are installed on the facade at 3m, 6m, and 9m above the ground. The top sprinkler pipe 4 is installed parallel to the roof ridge, with a total length of 7.0m.

[0054] Five thermocouple temperature measuring points are set up on the facade of the main body 1 at heights of 3m, 6m and 9m from the ground, with a spacing of 1.2m between the temperature measuring points, and thermocouples 7 are installed on the thermocouple temperature measuring points; preferably, thermocouples 7 are installed on the eaves of the roof 2; 5 heat flux meter measurement points are set corresponding to the temperature measuring points on the exterior wall at a height of 3m from the ground and 1m from the exterior wall of the building in the horizontal direction, with a spacing of 1.2m between the measurement points.

[0055] The camera is set at 6 meters in the direction of the horizontal center axis of the vertical experimental platform facade and 1.2 meters above the ground.

[0056] An infrared thermal imager 13 is placed 12 meters away from the central axis of the 4.8-meter-long side outer wall of the main body 1. The infrared thermal imager 13 is 1.0 m above the ground and images the entire experimental building target in real time in the form of a "surface". The image color and hot spot tracking displayed on the screen show the temperature changes of the building during the experiment.

[0057] The ignition system 14 includes a natural gas source and a main pipeline installed above it. The main pipeline is provided with several branch pipelines, each of which is installed with a valve, so that the ignition system 14 can realize different single-point ignition and multi-point simultaneous ignition, ensuring the standardization of ignition conditions.

[0058] The water collection system consists of a water collection box and an electronic balance installed below it. The data from the electronic balance can be transmitted to the data acquisition system. An electronic balance with data processing and transmission capabilities, such as the JS-A7 intelligent electronic balance, is equipped with an automatic weighing and recording system. This system uses automatic weighing software to record product weight information along with product attributes into a database, storing and exporting data for easy query and statistics of all weighing histories. This system also features a weighing information recording function, allowing users to customize the weighing data format as needed. The weighing system automatically saves all weighing data to a computer during weighing. When connected to a computer, data is automatically stored and exported at any time. Custom functions can also be developed.

[0059] The six water collection systems 9 are placed at the lower edge of the facade and connected seamlessly. The specifications of the water collection box are 800 mm in length and 400 mm in width.

[0060] The control method of this application is controlled by a controller. The control circuit of the controller can be implemented by simple programming by a person skilled in the art. The provision of power is also common knowledge in this field. This application is mainly used to include mechanical devices, so this application will no longer explain the control method and circuit connection in detail.

[0061] A method for testing exterior fire of buildings at the interface between forest and town, comprising the following steps:

[0062] S1. Build and debug the test equipment to ensure that the equipment reaches the predetermined state; conduct a cold spray test before conducting the fire extinguishing test to ensure that the fire extinguishing system can effectively cover the combustion area of ​​the ignition system. If it cannot cover the combustion area, the fire extinguishing system needs to be adjusted until it meets the requirements;

[0063] S2. Install and debug the backup fire extinguishing facilities for use. If the fire extinguishing system fails to extinguish the fire after being activated for a long period of time, immediately activate the backup fire extinguishing facilities to extinguish the fire. This fire extinguishing test is considered a failure. The test should be repeated after changing the fire extinguishing system supply intensity or other test conditions.

[0064] S3. Start the ignition system according to the predetermined plan, using different single-point ignition or multi-point simultaneous ignition according to the actual test situation. When the combustion system is burning, the measurement system will collect the burning flame height, the fire height of the building facade after the fire is extinguished, thermal radiation, visible light video data, the temperature field of the fire scene, and hot spot tracking to show the temperature changes of the building during the experiment and transmit them to the data acquisition system in real time;

[0065] S4. When the fire burns to the set position, the data acquisition system controls the water pump group according to the real-time data obtained, so that the sprinklers of the fire extinguishing system spray water until the fire is completely extinguished;

[0066] S5. The data acquisition system analyzes the data of the entire test process and gives the test results. After the test is completed, the test site is processed and prepared for the next test.

[0067] Blank experiment analysis

[0068] (1) Fire spread analysis

[0069] The flame spread to the top of the first floor 3 seconds after ignition, and spread to the roof 40 seconds after ignition. The whole building was engulfed in flames. The combustible materials were greatly reduced 100 seconds after ignition, and the open flames above the first floor of the facade were extinguished. The fire gradually subsided. The open flames on the facade surface were extinguished 240 seconds after ignition. The combustible materials produced by the combustion and melting of the facade flowed on the ground and continued to burn until the end of the experiment.

[0070] (2) Temperature field analysis

[0071] Thermocouples 26#~30# were placed at a height of 3 meters from the ground. During the experiment, the combustion was intense and two of the thermocouples were burned. The temperature range measured by the remaining thermocouples that were not burned fluctuated violently. From the time of ignition, the temperature rose sharply and the highest temperature exceeded the measuring range. About 40 seconds after ignition, the temperature slowly dropped. Figure 2 Thermocouples 31#~35# were placed at a height of 6 meters from the ground. During the experiment, the combustion was intense and one of the thermocouples here burned out. The temperature range measured by the remaining thermocouples that did not burn out fluctuated strongly. From 2 seconds after ignition, the temperature rose sharply and exceeded the maximum temperature range. The temperature reached its highest point about 40 seconds to 50 seconds after ignition, and then gradually decreased. See Figure 3Thermocouples 36#~40# were placed at a height of 9 meters from the ground. The temperature rose rapidly from about 22 seconds after ignition until it reached its maximum value about 40 seconds after ignition, indicating that the exterior wall insulation material at the height of 9 meters was at its most intense stage. After 20 seconds, the temperature gradually dropped and the fire gradually subsided. Figure 4 Thermocouples 41#~45# are placed at a height of 9 meters from the ground and 1 meter away from the outer wall. Figure 5 Thermocouples #11, 14, 17, 20, and 23 were placed 1 meter away from the facade and 1 meter high. During the experiment, the combustion was intense, and two of the thermocouples placed here burned out. The temperature range measured by the remaining thermocouples that did not burn out fluctuated violently, with the highest temperature exceeding the measuring range. For details, see Figure 6 Thermocouples #12, 15, 18, 21, and 24 were placed 1 meter from the facade and 2 meters high. During the experiment, the combustion was intense, and two of the thermocouples were burned. The temperature range measured by the remaining thermocouples that did not burn fluctuated violently, with the highest temperature being about 850°. Figure 7 Thermocouples #13, 16, 19, 22, and 25 were placed 1 meter from the facade and 3 meters high. During the experiment, the combustion was intense and all the thermocouples placed in these locations were burned.

[0072] (3) Thermal radiation analysis

[0073] Heat flux meters 1# to 3# were placed 1.2m to the left of the vertical centerline of the facade, at heights of 1m, 2m, and 3m. Heat flux meters 1# to 2# were damaged. Heat flux meters 4# to 6# were placed at heights of 1m, 2m, and 3m from the vertical centerline of the facade, respectively. From the start of ignition to the 20s stage, the thermal radiation value rose steadily, and the fire progressed steadily. Figure 8 . Then the fire developed violently, and the slope of the thermal radiation curve increased sharply. From ignition to 30s, the thermal radiation curve showed a peak value. The thermal radiation value at 3m was less than that at 6m, and the thermal radiation value at 6m was less than that at 9m. As the height increased, the thermal radiation value showed an increasing trend. Then the violent combustion process ended quickly, and the thermal radiation value dropped rapidly. The 7#~9# heat flux meters were arranged 1.2m to the right of the vertical center line of the facade, with heights of 1m, 2m, and 3m. Since the ignition source is set at the center of the facade, the closer to the center line, the higher the thermal radiation value, and the farther away from the center, the slower the rise of the thermal radiation value. The peak of the thermal radiation curve of the 4#~6# heat flux meters is earlier than that of other positions, and the trend is similar.

[0074] Analysis of Fire Extinguishing Experiment on Building Facade Fire

[0075] (1) Fire spread analysis

[0076] Five seconds after ignition, the flames spread to the top of the first floor and 30 seconds later to the top of the third floor. At this point, sidewall sprinklers installed 9 meters from the facade began dispensing water. 43 seconds after ignition, the fire's spread was significantly suppressed, and the intensity of the open flames was significantly reduced. 60 seconds after ignition, all open flames on the facade surface were extinguished. The melted combustible material from the facade flowed into the ignition oil pan and continued to burn. 120 seconds after ignition, the open flames in the pan were extinguished, and the experiment concluded.

[0077] (2) Temperature field analysis

[0078] Thermocouples 26#~30# were arranged at a height of 3 meters from the ground. During the experiment, the combustion was intense, and two of the thermocouples arranged here burned out. The temperature range measured by the remaining unburned thermocouples fluctuated violently. From the beginning of ignition, the temperature rose sharply, and the highest temperature exceeded the measuring range. About 40 seconds after ignition, the temperature slowly dropped.

[0079] (3) Thermal radiation analysis

[0080] Heat flux meter #2 is located 2.4m to the right of the vertical centerline of the facade and 3m from the facade, with a height of 3m. Heat flux meter #3 is located 3m from the vertical centerline of the facade and 5m from the facade, with a height of 3m. Heat flux meter #4 is located 1.2m to the right of the vertical centerline of the facade and 4m from the facade, with a height of 3m. Figure 9 The heat flux meter is set up in the following position. Figure 10 As shown in the figure, within 30 seconds of ignition, the thermal radiation value increased rapidly, and the fire spread rapidly to the top of the third floor. At this point, sprinklers began to spray water, which suppressed the fire and reduced the thermal radiation intensity by about 2 seconds. As the water droplets fell, the interaction between the droplets and the air caused disturbances in the air above the burning material, allowing some air to enter the combustion process, causing the fire to spread briefly. However, as the water droplets continued to fall, a relatively complete water droplet shield was formed outside the building, producing a significant cooling effect. The fire was stably and quickly suppressed until the flames were extinguished.

[0081] Fire extinguishing experiment on building roof fire

[0082] (1) Fire spread analysis

[0083] The fire spread slowly from the time it was ignited until 40 seconds after ignition. At 174 seconds, the fire area accounted for about 1 / 2 of the total area. At this time, the sprinklers installed on the roof ridge began to spray water. 184 seconds after ignition, the fire spread trend was significantly suppressed, and the flame intensity was significantly reduced. 200 seconds after ignition, most of the flames on the roof surface were extinguished. 410 seconds after ignition, all the flames on the roof surface were extinguished, and the experiment ended.

[0084] (2) Infrared thermal imaging images

[0085] From ignition to 40 seconds after ignition, the fire area gradually increases and the center flame temperature gradually increases. Figure 11 (a) As shown; the flame in the high temperature area expands rapidly at 80s. Figure 11 As shown in (b); At 174s, the sprinkler installed on the roof ridge starts to spray water. Under the action of water droplets, the flame temperature in the fire area is significantly reduced, as shown in Figure 11 As shown in (c), 184 seconds after ignition, the area of ​​the burning area in the high temperature zone further shrank, and the intensity of the open flame was significantly reduced. Figure 11 (d) As shown. 200s after ignition, the temperature of most of the bright area on the roof surface is in the blue band area, about 300°. Figure 11 As shown in (e); 410s after ignition, the entire roof surface area is in the low temperature zone and the open flames are completely extinguished. Figure 11 (f) shown.

[0086] Fire extinguishing experiment on stack fire outside a building

[0087] (1) Fire spread analysis

[0088] The fire spread slowly from the time it was ignited to 40 seconds after ignition. At 65 seconds, the fire area accounted for about 1 / 2 of the total area. At this time, the sprinklers installed on the roof ridge began to spray water. 70 seconds after ignition, the fire spread trend was significantly suppressed and the flame intensity was significantly reduced. 75 seconds after ignition, most of the flames on the stack surface were extinguished. 110 seconds after ignition, all the flames on the stack surface were extinguished, and the experiment ended.

[0089] (2) Infrared thermal imaging

[0090] From the time of ignition to 70 seconds after ignition, the fire spreads slowly, the temperature of the central flame area gradually rises, and the burning area gradually expands. Figure 12 (a) ~ such as Figure 12 75s after ignition, the nozzle starts to spray water, and the stack is cooled by the water droplets. The surface temperature of the stack drops and the high-temperature flame area shrinks, as shown in Figure 3. Figure 12 (e) As shown: 110s after ignition, all open flames on the stack surface are extinguished, as shown in Figure 12 As shown in (f), the experiment ends.

[0091] Once a fire at the forest-urban interface reaches a building, it could potentially cause fires in the building's exterior insulation and surrounding structures. Once a fire occurs in a building's exterior insulation material, it burns very quickly due to its flammability. The fire could quickly spread upward or downward through the exterior wall, forming a large, three-dimensional fire, which not only increases the difficulty of firefighting but also can cause even more serious property damage. On the one hand, when a fire spreads from the exterior insulation of a building at the forest-urban interface, a simple fixed fire extinguishing system, such as a water sprinkler system, can be used to preemptively spray water on the building's exterior walls and surrounding debris to cool down combustible materials, thereby achieving both fire prevention and fire extinguishing effects.

[0092] Therefore, in response to the demand for fixed suppression of fires in the interface area, the study proposed a simple water spray system based on a fixed water sprinkler fire extinguishing system, which can effectively achieve the disposal of fires outside buildings in the interface area. For the proposed fixed suppression technology, cold spray experiments on system parameter selection, fire extinguishing effects on building facades, fire extinguishing effects on building roofs, and fire extinguishing effects on stacks around buildings were carried out. The results show that the proposed fixed fire extinguishing technology for interface fires can achieve early prevention and fire fighting of interface fires. In response to the demand for fire suppression in the interface area, a single nozzle of the fixed suppression technology can achieve a maximum protection area of ​​1.8m wide and 9m high, and a single set of simple water spray systems can protect 210m of the building facade. 2 、Building outer area 60m 2 , and can provide continuous fire suppression protection.

[0093] The above description is only a preferred 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 fire test device for buildings located at the interface between forest and town, characterized by: It includes a combustion system and an air blowing system, ignition system, water collection system, measurement system and data acquisition system installed on one side of the combustion system. The combustion system is the overall building structure. The air blowing system is used to measure the impact of wind speeds at different angles on fires outside the building. The ignition system is used to ensure the standardization of ignition conditions. The water collection system is located below the combustion system and is used to collect water. The measurement system is used to measure the temperature, thermal radiation and flame size during the combustion process of the combustion system. The combustion system is also equipped with a fire extinguishing system, which is used to test the fire extinguishing effectiveness. The data acquisition system is connected to the air blowing system, fire extinguishing system and measurement system respectively.

2. The exterior fire test device for buildings at the forest-town interface according to claim 1, characterized in that: The bottom of the blowing system is equipped with universal wheels that can rotate 360 ​​degrees.

3. The exterior fire test device for buildings at the forest-town interface according to claim 1, characterized in that: The combustion system includes the main body and the roof and square tubes installed above it. The main body and the roof are welded from galvanized square tubes. The overall dimensions of the main body are 9m high, 4.8m long, and 5m wide. The height of each floor is 3m. The side wall facade of the main body can be removably installed with cement boards and insulation materials.

4. The exterior fire test device for buildings at the forest-town interface according to claim 1, characterized in that: The ignition system includes a natural gas source and a main pipeline installed above it. The main pipeline is equipped with several branch pipelines, each of which is equipped with a valve, so that the ignition system can realize different single-point ignition and multi-point simultaneous ignition, ensuring the standardization of ignition conditions.

5. The exterior fire test device for buildings at the forest-town interface according to claim 2, characterized in that: The fire extinguishing system includes a top sprinkler pipe, No. 1 sprinkler, No. 2 sprinkler, a water tank and a water pump group. The top sprinkler pipe is installed above the main body, and the top sprinkler pipe is equipped with several No. 1 sprinklers with adjustable angles. Several sprinkler pipes are installed at equal intervals from top to bottom on the exterior wall facade of the main body. Each sprinkler pipe is equipped with several No. 2 sprinklers with adjustable angles and retractable lengths. The top sprinkler pipe and the sprinkler pipe are connected to the water tank through the water pump group.

6. The exterior fire test device for buildings at the forest-town interface according to claim 1, characterized in that: The water collection system is a water collection box and an electronic balance installed below it. The data from the electronic balance can be transmitted to the data acquisition system.

7. The exterior fire test device for buildings at the forest-town interface according to claim 2, characterized in that: The measurement system includes a height gauge, thermocouples, a heat flux meter, a camera, and an infrared thermal imager. Several thermocouple groups, each containing several thermocouples, are evenly spaced from top to bottom on the exterior facade of the main structure. A height gauge, a heat flux meter, a camera, and an infrared thermal imager are also installed on the exterior of the main structure. The height gauge is used to measure the height of the burning flames and the height of the building's facade after the fire is extinguished. The heat flux meter is used to test thermal radiation, the camera is used to collect visible light video data, and the infrared thermal imager is used to measure the temperature field of the fire scene and track hot spots to display temperature changes in the building during the experiment. The heat flux meter, camera, infrared thermal imager, water pump group, electronic balance, and thermocouple signals are all connected to the data acquisition system.

8. The exterior fire test device for buildings at the forest-town interface according to claim 1 is characterized by: The data acquisition system is a computer or industrial computer.

9. The exterior fire test device for buildings at the forest-town interface according to claim 7, characterized in that: Five thermocouple temperature measuring points are set up on the side wall facade of the main body at heights of 3m, 6m and 9m from the ground. The distance between adjacent temperature measuring points is 1.2m, and thermocouples are installed on the thermocouple temperature measuring points.

10. The exterior fire test device for buildings at the forest-town interface according to claim 7, characterized in that: An infrared thermal imager is placed 12 meters away from the central axis of the 4.8-meter-long side exterior wall of the main body. The infrared thermal imager is 1.0 meters above the ground and can image the entire experimental building target in real time in the form of a "surface". The image color and hotspot tracking displayed on the screen show the temperature changes of the building during the experiment.

11. The exterior fire test device for buildings at the forest-town interface according to claim 5, characterized in that: An upright sprinkler head is installed in the center of the top sprinkler pipe, and drooping sprinkler heads are installed at both ends. The distance between two adjacent sprinkler heads can be adjusted.

12. The exterior fire test device for buildings at the forest-town interface according to claim 5, characterized in that: Sprinkler pipes are installed on the facade of the main body at 3m, 6m and 9m from the ground, and the top sprinkler pipe is installed parallel to the ridge.

13. The exterior fire test device for buildings at the forest-town interface according to claim 7, characterized in that: The camera is set at 6 meters in the direction of the horizontal center axis of the vertical main facade and 1.2 meters above the ground.

14. A method for testing exterior fires in buildings at the interface between forests and towns, characterized in that: The application of the exterior fire test device for buildings at the forest-town interface as described in any one of claims 1 to 13 comprises the following steps: S1. Build and debug the test equipment to ensure that the equipment reaches the predetermined state; conduct a cold spray test before conducting the fire extinguishing test to ensure that the fire extinguishing system can effectively cover the combustion area of ​​the ignition system. If it cannot cover the combustion area, the fire extinguishing system needs to be adjusted until it meets the requirements; S2. Install and debug the backup fire extinguishing facilities for use. If the fire extinguishing system fails to extinguish the fire after being activated for a long period of time, immediately activate the backup fire extinguishing facilities to extinguish the fire. This fire extinguishing test is considered a failure. The test should be repeated after changing the fire extinguishing system supply intensity or other test conditions. S3. Start the ignition system according to the predetermined plan, using different single-point ignition or multi-point simultaneous ignition according to the actual test situation. When the combustion system is burning, the measurement system will collect the burning flame height, the fire height of the building facade after the fire is extinguished, thermal radiation, visible light video data, the temperature field of the fire scene, and hot spot tracking to show the temperature changes of the building during the experiment and transmit them to the data acquisition system in real time; S4. When the fire burns to the set position, the data acquisition system controls the water pump group according to the real-time data obtained, so that the sprinklers of the fire extinguishing system spray water until the fire is completely extinguished; S5. The data acquisition system analyzes the data of the entire test process and gives the test results. After the test is completed, the test site is processed and prepared for the next test.

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