Experimental device and method for simulating fire spread of electric wire and cable under limited structure

Abstract

The invention discloses an experimental device for simulating fire spread of wires and cables under a limited structure, which comprises a limited model main body, and the limited model main body comprises four closing plates and two groups of adjustable mounting brackets; the two sets of adjustable mounting supports are symmetrically arranged, each set of adjustable mounting support comprises two first supporting rods, two L-shaped supporting frames and a vertical distance adjusting assembly, the two first supporting rods are vertically arranged in parallel, and the two L-shaped supporting frames are horizontally and slidably connected to the upper sides and the lower sides of the interiors of the two first supporting rods; the vertical distance adjusting assembly is connected between the two L-shaped supporting frames, two sealing plates are horizontally erected between the two L-shaped supporting frames respectively, and the other two sealing plates are vertically, correspondingly and detachably connected with the first supporting rods in the two sets of adjustable mounting supports. According to the invention, the size of the limited space and the limited sealing degree can be adjusted, the problem that the sealing degree and the size of the limited space are not adjusted at present is solved, and a reference value is provided for the fire spread combustion rule of wires and cables under a limited structure.

Description

Technical Field

[0001] The invention relates to the technical field of fire spread of electric wires and cables, and in particular to a fire spread experimental device and method for simulating fire spread of electric wires and cables under a restricted structure. Background Art

[0002] In recent years, with the rapid development of the economy, fires have occurred frequently, threatening the safety of life and property of urban and rural residents. Wires and cables are also one of the factors that cause fires. They are widely present in residential and various commercial civil buildings and are potential dangers. If there is poor contact, short circuit or high ambient temperature, it is easy to cause a fire and cause casualties.

[0003] At present, the research on wires and cables is mainly carried out in open environments, and the experimental equipment and methods for studying the spread of fire in wires and cables are studied. However, the environmental conditions of wires and cables in commercial and civilian fields are often more complex and have more restrictions. Therefore, it is particularly important to study the fire spread characteristics of wires and cables under restricted structures.

[0004] Through investigation and analysis, it is found that wires and cables are often in confined situations, and there are many influencing factors, such as the size of the confined space, the degree of enclosure, wind speed, cable spacing, tilt angle, etc., which will affect them. In confined spaces, the burning of wires and cables will spread rapidly. If not handled properly, it will cause a lot of losses. Therefore, it is necessary to pay attention to the coupling factors of the spread of wire and cable fire under confined structures.

[0005] At present, some experimental devices for studying the fire spread characteristics of wires and cables mostly only adjust the wind speed, cable spacing, and inclination angle under the confined structure, but lack the adjustment of the size and degree of enclosure of the confined space. This leads to certain limitations in the experimental research and makes it difficult to accurately simulate the fire spread characteristic parameters of wires and cables under different confined conditions. Summary of the invention

[0006] The purpose of the present invention is to provide a fire spread experimental device for wires and cables under a confined structure, which can not only adjust the wind speed, cable spacing and inclination angle under the confined structure, but also adjust the size of the confined space and the degree of confined enclosure, so as to simulate the fire spread characteristic parameters of wires and cables under different confined conditions, and provide reference value for the fire spread and combustion law of wires and cables under confined structures.

[0007] The technical solution of the present invention is: a fire spread experimental device for simulating electric wires and cables under a confined structure, comprising a confined model main body, the confined model main body comprising four closing plates and two groups of adjustable mounting brackets; the two groups of adjustable mounting brackets are symmetrically arranged, each group of adjustable mounting brackets comprises two first support rods, two L-shaped support frames and a vertical spacing adjustment component, the two first support rods are vertically arranged in parallel, the two L-shaped support frames are horizontally slidably connected to the upper and lower sides of the inside of the two first support rods, the vertical spacing adjustment component is connected between the two L-shaped support frames, and is used to adjust the vertical spacing of the two L-shaped support frames, wherein the two closing plates are respectively horizontally arranged between the two L-shaped support frames in the two groups of adjustable mounting brackets, and the other two closing plates are vertically arranged, and are respectively detachably connected to the outer side walls of the first support rods in the two groups of adjustable mounting brackets, and a bridge frame for placing cables is connected to the opposite plate surfaces of the two vertically arranged closing plates.

[0008] The vertical spacing adjustment mechanism includes a first adjusting bolt, the first support rod is U-shaped, and the opening is arranged with its back to the L-shaped support frame, a vertically arranged first strip through groove is provided on the inner wall of the opening of the first support rod, a second strip through groove is provided on the plate surface of two vertically arranged closing plates facing the first strip through groove, and a third strip through groove is provided on the side wall of the L-shaped support frame facing the closing plate, the first adjusting bolt is horizontally penetrated between the first strip through groove, the second strip through groove and the third strip through groove, and the closing plate is clamped between the L-shaped support frame and the first support rod.

[0009] A second support rod is provided at the bottom of the two first support rods in each group of the adjustable mounting brackets, and the second support rod is vertically arranged with the first support rod, and two third support rods are vertically fixed between the two second support rods, and the first support rod is slidably connected with the third support rod, and the tops of the two first support rods in each group of the adjustable mounting brackets are fixed by a fourth support rod, and a horizontal spacing adjustment mechanism is provided between the first support rods in the two groups of adjustable mounting brackets, and the horizontal spacing adjustment mechanism is used to adjust the horizontal spacing of the first support rods in the two groups of adjustable mounting brackets.

[0010] The horizontal spacing adjustment mechanism includes a slider and a second adjusting bolt. The slider is fixed to the bottom side wall of the first support rod. The bottom of the slider is slidably connected to the third support rod. The top of the third support rod is provided with a fourth strip through groove arranged along its length direction. The side wall of the slider facing the fourth strip through groove is provided with a through opening for the second adjusting bolt to pass through. The second adjusting bolt is vertically penetrated in the through opening and the fourth strip through groove and connects the slider to the third support rod.

[0011] One of the vertically arranged closing panels is a glass observation panel, and the other three closing panels are gypsum panels.

[0012] An inclination adjustment mechanism is provided at the bottom of the two second support rods, and the inclination adjustment mechanism includes a base, two support rods and two third adjustment bolts. The two support rods are vertically fixed on both sides of the top of the base, and the two support rods are located on the outside of the two second support rods. The two support rods are connected to the two second support rods respectively by two third adjustment bolts.

[0013] A protractor is fixed on the bottom side wall of the second support rod. A hole groove is provided at the center of the horizontal side of the protractor, and the protractor is rotatably connected to the third adjusting bolt through the hole groove.

[0014] Cable spacing adjustment brackets are respectively provided on the left and right sides of the restricted model body, and the cable spacing adjustment brackets include a supporting slide rail and a plurality of cable brackets. The supporting slide rail is vertically arranged, and the plurality of cable brackets are arranged perpendicular to the slide rail and are slidably connected to the supporting slide rail. Each cable bracket is provided with a cable clamp for fixing the cable.

[0015] It also includes a wind tunnel, an image acquisition system, a temperature acquisition system, a blowing system, an ignition system and a central control system; the wind tunnel has a rectifying section and an experimental section, and the confined model body is arranged in the experimental section; the image acquisition system is arranged on a side close to the glass observation plate, and is used to record the entire flame diffusion process in the confined space and the temperature field changes during flame combustion; the temperature acquisition system is used to record the temperature conditions of the wires and cables when they are burning; the blowing system is arranged in the wind tunnel, and is used to provide wind speeds of different sizes to simulate the flame combustion characteristics in a windy environment; the ignition system is used to ignite the wires and cables; the central control system is electrically connected to the image acquisition system, the temperature acquisition system, the blowing system and the ignition system respectively.

[0016] An experimental method based on the above-mentioned experimental device for simulating fire spread of wires and cables under a confined structure comprises the following steps:

[0017] Installing gypsum boards on the upper and lower rear sides of the restricted model body respectively, and installing a glass observation panel on the front side of the restricted model body;

[0018] Place the blowing system at the experimental location and adjust the wind speed of the blowing system to provide the required experimental wind speed;

[0019] Debug the image acquisition system and set it on the side close to the glass observation panel to record the entire flame diffusion process in the confined space and the temperature field changes during flame combustion;

[0020] The temperature acquisition system is installed on the front and rear sides of the restricted model body to record the temperature of the wires and cables when they are burning;

[0021] Arrange cables on the confined model body, and adjust the size of the confined space, the degree of confined enclosure, the spacing of wires and cables, the wind speed, and the inclination angle of the confined model body according to the experimental requirements;

[0022] The ignition system is used to ignite the wires and cables, and the flames gradually spread. The image acquisition system is used to collect the combustion conditions inside the restricted model body. When the wires and cables are completely burned, the experiment ends.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention can adjust the size of the confined space by adjusting the spacing between the upper and lower horizontally arranged closing plates through the cooperation between the vertical spacing adjustment mechanism and the confined model body. At the same time, since the upper and lower horizontally arranged closing plates can be removed from the L-shaped bracket, the degree of confined closure can be flexibly adjusted, and the fire spread experiment when four sides are restricted, three sides are restricted, and two sides are restricted can be simulated according to the number of closed plates removed, which solves the current problem of lack of adjustment of the degree of closure and the size of the confined space, and provides reference value for the fire spread and combustion law of wires and cables under confined structures.

[0025] 2. The horizontal spacing adjustment mechanism of the present invention can adjust the spacing between the front and rear two vertically arranged closing plates to further adjust the size of the confined space.

[0026] 3. The present invention also has the function of adjusting the cable spacing, inclination angle, and wind speed. It can be used to simulate various structures such as pipe galleries, shafts, and bridges. It can be combined with various detection devices to explore the fire spread characteristic parameters under different restricted structures and study the fire spread mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0028] Figure 2 It is a partially enlarged three-dimensional structural schematic diagram of the restricted model body in the present invention;

[0029] Figure 3 It is a schematic diagram of the main structure of the restricted model body in the present invention;

[0030] Figure 4 It is a rear view structural schematic diagram of the present invention;

[0031] Figure 5 It is a schematic diagram of the structure of the restricted model body in the present invention when it is restricted on four sides;

[0032] Figure 6 It is a schematic diagram of the structure of the restricted model body in the present invention when it is restricted on three sides;

[0033] Figure 7 It is a schematic diagram of the structure of the restricted model body in the present invention when it is restricted on two sides;

[0034] Figure 8 It is a schematic diagram of the structure of the restricted model body in the present invention when it is flipped to a vertical position;

[0035] Fig. 9 It is an exploded schematic diagram of the connection between the horizontal spacing adjustment mechanism and the vertical spacing adjustment mechanism in the present invention;

[0036] Fig.10 A schematic diagram of the connection between the L-shaped support frame and the third support rod in the present invention;

[0037] Fig.11 It is a structural schematic diagram of the cable spacing adjustment bracket added in the present invention;

[0038] Fig.12 The overall structure diagram of the experimental device for simulating fire spread of wires and cables under a confined structure of the present invention is shown in FIG.

[0039] Fig.13 It is a schematic structural diagram of the ignition system in the present invention;

[0040] Fig.14 It is a connection diagram of the temperature acquisition system in the present invention. DETAILED DESCRIPTION

[0041] The following is combined with Figures 1 to 14 , the specific embodiments of the present invention are described in detail. In the description of the invention, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the 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.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features specified as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of the invention, unless otherwise specified, "plurality" means two or more.

[0043] Example 1

[0044] like Figures 1 to 10As shown, an embodiment of the present invention provides a fire spread experimental device for wires and cables under a confined structure, including a confined model body 4, the confined model body 4 includes four closing plates and two groups of adjustable mounting brackets; the two groups of adjustable mounting brackets are symmetrically arranged, each group of adjustable mounting brackets includes two first support rods 11, two L-shaped support frames 29 and a vertical spacing adjustment component, the two first support rods 11 are vertically and parallelly arranged, the two L-shaped support frames 29 are horizontally slidably connected to the upper and lower sides of the inside of the two first support rods 11, the vertical spacing adjustment component is connected between the two L-shaped support frames 29, and is used to adjust the vertical spacing of the two L-shaped support frames 29, wherein the two closing plates are respectively horizontally arranged between the two L-shaped support frames 29 in the two groups of adjustable mounting brackets, and the other two closing plates are vertically arranged, and are respectively detachably connected to the outer side walls of the first support rods 11 in the two groups of adjustable mounting brackets, and the bridge frame 7 for placing the cable 8 is connected to the opposite plate surfaces of the two vertically arranged closing plates.

[0045] In this embodiment, the vertical spacing adjustment component can adjust the spacing between the upper and lower horizontally arranged closing plates, thereby adjusting the upper and lower spacing of the confined space, so that the experimental device can adjust the size of the confined space according to the experimental requirements. At the same time, since the upper and lower horizontally arranged closing plates are arranged between the two L-shaped support frames 29 in the two sets of adjustable mounting brackets, refer to Figures 5 to 7 As shown, the fire spread experiments when the cables are restricted on four sides, three sides and two sides can be simulated by controlling the number of closed plates removed, so as to adjust the degree of restricted enclosure and simulate the fire spread characteristic parameters of wires and cables under different restricted conditions, thereby providing a reference for the fire spread and combustion law of wires and cables under restricted structures.

[0046] Specifically, Figure 2 , Figure 3 and Fig. 9 As shown, as an optional implementation of the vertical spacing adjustment mechanism, the vertical spacing adjustment mechanism includes a first adjusting bolt 30, the first support rod 11 is U-shaped, and the opening is arranged with its back to the L-shaped support frame 29, a vertically arranged first strip through groove 31 is provided on the inner wall of the opening of the first support rod 11, and a second strip through groove 32 is provided on the plate surface of two vertically arranged closing plates facing the first strip through groove 31, and a third strip through groove 33 is provided on the side wall of the L-shaped support frame 29 facing the closing plate, and the first adjusting bolt 30 is horizontally penetrated between the first strip through groove 31, the second strip through groove 32 and the third strip through groove 33 to clamp the closing plate between the L-shaped support frame 29 and the first support rod 11.

[0047] Reference Fig. 9As shown, when the vertical spacing of the horizontally arranged closing plates on the upper and lower sides is adjusted by the vertical spacing adjustment mechanism, the first adjusting bolt 30 is first inserted into the first strip through slot 31 opened by the first support rod 11, and then inserted into the second strip through slot 32 on the glass closing plate, and then inserted into the third strip through slot 33 of the L-shaped support frame 29. The first adjusting bolt 30 achieves the function of connecting the three. The first adjusting bolt 30 can move up and down in the first strip through slot 31 and the second strip through slot 32, thereby driving the L-shaped bracket to move up and down. Since the upper closing plate is placed on the bottom surface of the L-shaped bracket 29, the upper closing plate achieves a supporting effect through the L-shaped bracket 29 on the front and rear sides. Therefore, by adjusting the vertical position of the first adjusting bolt 30 in the first strip through slot 31 and the second strip through slot 32, the position of the L-shaped bracket in the vertical direction is adjusted, and the upper closing plate can also be positioned at different vertical positions.

[0048] Furthermore, in order to be able to adjust the horizontal spacing between the vertically arranged front and rear side closing plates, such as Figure 2 As shown, a second support rod 9 is provided at the bottom of the two first support rods 11 in each set of adjustable mounting brackets, the second support rod 9 is vertically arranged with the first support rod 11, two third support rods 10 are vertically fixed between the two second support rods 9, the first support rod 11 is slidably connected with the third support rod 10, the tops of the two first support rods 11 in each set of adjustable mounting brackets are fixed by a fourth support rod 2, and a horizontal spacing adjustment mechanism is provided between the first support rods 11 in the two sets of adjustable mounting brackets, and the horizontal spacing adjustment mechanism is used to adjust the horizontal spacing of the first support rods 11 in the two sets of adjustable mounting brackets.

[0049] In this embodiment, since the first support rod 11 is slidably connected to the third support rod 10, the horizontal spacing of the first support rods 11 in the adjustable mounting bracket can be adjusted by the provided horizontal spacing adjustment mechanism. At the same time, since the tops of the two first support rods 11 in each group of adjustable mounting brackets are fixed by the fourth support rod 2, the two first support rods 11 in each group of adjustable mounting brackets can be ensured to move synchronously, thereby driving the vertically arranged front and rear side closing plates to approach or move away from each other, thereby realizing the adjustment process of the horizontal spacing of the vertically arranged front and rear side closing plates, thereby realizing the adjustment of the front and rear distance of the confined space.

[0050] Specifically, Figure 2 , Figure 3 and Fig. 9As shown, the horizontal spacing adjustment mechanism includes a slider 34 and a second adjusting bolt 35. The slider 34 is fixed to the bottom side wall of the first support rod 11. The bottom of the slider 34 is slidably connected to the third support rod 10. The top of the third support rod 10 is provided with a fourth strip through groove 36 arranged along its length direction. The side wall of the slider 34 facing the fourth strip through groove 36 is provided with a through hole for the second adjusting bolt 35 to pass through. The second adjusting bolt 35 is vertically penetrated in the through hole and the fourth strip through groove 36, and connects the slider 34 to the third support rod 10.

[0051] Reference Fig. 9 As shown, when the horizontal spacing between the front and rear closing plates is adjusted by the horizontal spacing adjustment mechanism, the upper and lower closing plates horizontally arranged on the upper and lower sides are first removed from the L-shaped brackets 29, and then the second adjusting bolt 35 is inserted into the through-mouth groove of the slider 34, and then inserted into the fourth strip through-slot 36 opened on the third support rod 10. The second adjusting bolt 35 can move left and right in the fourth strip through-slot 36. Since the second adjusting bolt 35 is connected to a part of the structure of the first support rod 11, it drives the first support rod 11 to move left and right, and then drives the vertically arranged closing plates to move left and right synchronously through the first support rod 11, thereby adjusting the horizontal spacing between the front and rear closing plates, and then adjusting the front and rear distance of the confined space. After that, the disassembled upper and lower horizontally arranged closing plates can be replaced with those of different widths to adapt to the spacing between the front and rear L-shaped brackets 29, and the replaced horizontally arranged closing plates can be put back between the two L-shaped brackets 29.

[0052] Further, such as Figure 5 As shown, in order to facilitate the observation and recording of the fire spread characteristics experimental process of electric wires and cables in a confined space, one of the vertically arranged closing panels is a glass observation panel 28, and the other three closing panels are gypsum panels 25.

[0053] Further, such as Figure 1 and Figure 8 As shown, in order to be able to adjust the inclination angle of the restricted model body 4 to simulate the restricted situation under the shaft structure, an inclination adjustment mechanism is provided under the restricted model body 4, and the inclination adjustment mechanism includes a base 13, two support rods 14 and two third adjusting bolts 16. The two support rods 14 are vertically fixed on both sides of the top of the base 13, and the two support rods 14 are located on the outside of the two second support rods 9. The two support rods 14 are connected to the two second support rods 9 respectively by two third adjusting bolts 16. When adjusting the inclination angle, first loosen the nut on the third adjusting bolt 16 to release the locking function, and then adjust the inclination angle of the restricted model body 4 by rotating the second support rod 9. After adjustment, tighten the nut on the third adjusting bolt 16 to use friction to lock the current inclination angle of the restricted model body 4.

[0054] Further, such as Figure 1 As shown, in order to improve the stability of the support rod 14, reinforcing ribs are fixed on both sides of the support rod 14, and the other ends of the two reinforcing ribs are fixed to the top of the base 13, and the reinforcing ribs are inclined at 45 degrees.

[0055] Furthermore, if Figure 1 As shown, in order to measure the tilt angle, a protractor 15 is fixed on the bottom side wall of the second support rod 9. A hole groove is provided at the center of the horizontal side of the protractor 15, and the protractor 15 is rotatably connected to the third adjusting bolt 16 through the hole groove.

[0056] Furthermore, if Figure 2 As shown, in order to record the flame front spreading position, a scale is installed on the second support rod 9 located at the front side.

[0057] Further, such as Fig.11 As shown, in order to be able to adjust the spacing between cables, cable spacing adjustment brackets are respectively provided on the left and right sides of the restricted model body 4, and the cable spacing adjustment bracket includes a supporting slide rail 27 and a plurality of cable brackets 26. The supporting slide rail 27 is vertically arranged, and the plurality of cable brackets 26 are arranged perpendicular to the supporting slide rail 27 and are slidably connected to the supporting slide rail 27. A locking mechanism is provided on the supporting slide rail 27, which can fix the height position of the cable bracket 26 after moving it. Each cable bracket 26 is provided with a cable clamp for fixing the cable. When the cable spacing adjustment bracket is used to adjust the spacing between the cables, the vertical spacing between the cable brackets 26 is adjusted by sliding the cable bracket 26, so that the layered spacing between different cables can be adjusted, and the horizontal spacing between adjacent cables can be adjusted by changing the position of the cable clamp provided on the cable bracket 26.

[0058] like Figure 12 to Figure 14 As shown, another embodiment of the present invention further includes a wind tunnel 1, an image acquisition system 5, a temperature acquisition system, a blowing system, an ignition system and a central control system 6; the wind tunnel 1 has a rectifying section 2 and an experimental section 3, and the restricted model body 4 is arranged in the experimental section 3;

[0059] Among them, Fig.12As shown, the image acquisition system 5 is arranged on a side close to the glass observation plate 28. The image acquisition system 5 includes a camera 5a and an infrared thermal imager 5b. The camera 5a is used to record the fire spread characteristics of the wires and cables in a confined space. The infrared thermal imager 5b is used to record the temperature field changes during flame combustion and analyze the heat transfer during flame combustion through video. The camera 5a uses a high-definition digital camera of model FDR-AX60 to record the entire experiment and study the fire spread characteristics of the wires and cables in a confined space, such as flame shape, flame width and height, flame inclination angle, etc. The infrared thermal imager 5b is produced by FLIR Corporation and has a model of FLIR T865. There are three temperature measurement ranges, namely: -40°C to 120°C, 0°C to 650°C and 300°C to 2000°C. Its infrared resolution can reach 640×480 pixels, and it can automatically focus on the flame during shooting, which improves the shooting effect and meets the experimental requirements.

[0060] The temperature acquisition system includes two thermocouples 17 and a data acquisition instrument 18. Figure 1 and Figure 4 As shown, one thermocouple 17a is vertically installed on the front side of the restricted model body 4, and the other thermocouple 17b is horizontally installed on the rear side of the restricted model body 4. Both thermocouples 17 are K-type thermocouples, which have a temperature measurement range of -200°C to 1600°C and a fast temperature measurement speed. Fig.12 and Fig.14 As shown, the data acquisition instrument 18 uses Agilent 34970A data acquisition instrument and ICP DAS i-7018 thermocouple input module (needs to be used with RS-232 to RS-485 signal conversion module), which can connect a large number of thermocouples and collect data quickly, 10 times per second. The vertically arranged thermocouple 17a is used to measure the temperature stratification of the flame in the vertical direction when the fire spreads to the stable stage in the confined space. The horizontal thermocouple 17b is used to measure the temperature change in the longitudinal direction from the beginning to the end of the cable combustion process.

[0061] The blowing system includes a fan, which is arranged on one side of the restricted model body 4 and is used to provide wind speeds of different sizes for conducting experimental research on flame combustion characteristics in a windy environment. The fan uses an SF5-4 axial flow fan to provide the required wind speed for the experiment. The maximum power of the SF5-4 axial flow fan is 750W, the maximum speed is 1450 rpm, and the maximum air volume is 10000m3 / h. The wind speed can be adjusted by the frequency conversion knob during the experiment;

[0062] Among them, Fig.13As shown, the ignition system includes a propane gas tank 19, a pressure valve 20, a first flame arrester 21, a second flame arrester 22, a flow meter 23 and a plurality of burners 24 connected in sequence through pipelines. Propane is used to provide a heat source and supply gas to the linear burners 24 (three layers in total), so that a linear ignition experiment of a wire and cable bundle under different powers can be realized, and preliminary preparations are made for the fire spread experiment. A linear ignition source has been developed, so as to achieve uniformity and synchronization in the ignition process;

[0063] Among them, Fig.12 As shown, the central control system 6 includes a controller and a power supply component, and the controller is electrically connected to the image acquisition system 5, the temperature acquisition system, the wind speed system and the ignition system respectively.

[0064] Furthermore, the present invention also discloses an experimental method based on the experimental device for simulating fire spread of wires and cables under a confined structure in the above embodiment, comprising the following steps:

[0065] Gypsum boards 25 are installed on the upper and lower rear sides of the restricted model body 4 respectively, and a glass observation panel 28 is installed on the front side of the restricted model body 4.

[0066] Place the blowing system at the experimental position, place the fan 1 at a suitable position according to the experimental requirements, and provide a certain required experimental wind speed.

[0067] Debug the image acquisition system 5, place the camera and infrared thermal imager in front of the glass plate, and record the entire flame diffusion process to obtain the flame shape, flame height and width, flame merging, etc. The acquisition and analysis of flame images are crucial. During the experiment, the entire fire spread process was filmed.

[0068] Check the temperature acquisition system to ensure that the two thermocouples 17 are fixed in place and the data acquisition module 18 is intact. This is used to measure the temperature distribution and change pattern of the fire spread of wires and cables in confined spaces. Thermocouples can measure the temperature more accurately, which is acquired by the temperature acquisition instrument and then connected to the computer via a data cable to achieve real-time temperature recording under confined structures.

[0069] Arrange cables on the restricted model body 4, and adjust the size of the restricted space, the degree of restricted enclosure, the spacing of wires and cables, the wind speed, and the inclination angle of the restricted model body 4 according to the experimental requirements. After the arrangement is completed, prepare to start the experiment.

[0070] The ignition system is used to ignite the wires and cables, and the flame gradually spreads. The image acquisition system is used to capture the internal combustion conditions of the restricted model body 4. When the wires and cables are completely burned, the experiment ends.

[0071] After the experiment, the flame video was edited and preprocessed using Adobe Premiere software, and then the preprocessed video was processed using Matlab software. Thousands of grayscale images were obtained for each video. At this time, according to the reference points set before the experiment, the pixel difference of the flame was measured and proportionally converted to obtain the flame height, flame width, flame front position, and flame tail position.

[0072] In summary, the present invention obtains the situation during the fire spread of wires and cables: the temperature change distribution during the fire spread of wires and cables is obtained through the temperature acquisition system, and the fire spread characteristics of wires and cables, such as flame shape, flame height and width, flame merging, etc., are obtained through the image acquisition system. Different air volumes are provided by the wind speed system. The linear ignition experiment of wire and cable bundles under different power can be realized by supplying air to the linear burner through the ignition system. The cable is fixed inside the confined space through the fixing system. The confined system realizes the influence of the size of the confined space, the degree of confined closure, the cable spacing, the inclination angle and the wind speed respectively, and studies the fire spread characteristics under the coupling of the above-mentioned multiple factors and the combustion law under the confined structure, revealing the degree of correlation between the confined structure and the fire spread, as well as the wind speed suppression and acceleration of the fire spread mechanism.

[0073] The above disclosures are only several preferred specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A fire spread test device for simulating electric wires and cables under a confined structure, comprising a confined model body (4), characterized in that: The restricted model body (4) comprises: four closing panels; Two groups of adjustable mounting brackets are symmetrically arranged, and each group of adjustable mounting brackets includes two first support rods (11), two L-shaped support frames (29) and a vertical spacing adjustment component. The two first support rods (11) are arranged vertically and in parallel, and the two L-shaped support frames (29) are horizontally slidably connected to the upper and lower sides of the interior of the two first support rods (11). The vertical spacing adjustment component is connected between the two L-shaped support frames (29) and is used to adjust the vertical spacing of the two L-shaped support frames (29). Two closing plates are respectively and horizontally arranged between the two L-shaped support frames (29) in the two groups of adjustable mounting brackets, and the other two closing plates are arranged vertically and are respectively and detachably connected to the outer side walls of the first support rods (11) in the two groups of adjustable mounting brackets. A bridge frame (7) for placing cables (8) is connected to the opposite plate surfaces of the two vertically arranged closing plates.

2. The fire spread test device for wires and cables under a confined structure according to claim 1 is characterized in that: The vertical spacing adjustment mechanism comprises a first adjustment bolt (30); the first support rod (11) is U-shaped, and the opening is arranged with its back facing the L-shaped support frame (29); a vertically arranged first strip through groove (31) is arranged on the inner wall of the opening of the first support rod (11); a second strip through groove (32) is arranged on the plate surface of two vertically arranged closing plates facing the first strip through groove (31); a third strip through groove (33) is arranged on the side wall of the L-shaped support frame (29) facing the closing plate; the first adjustment bolt (30) is horizontally inserted between the first strip through groove (31), the second strip through groove (32) and the third strip through groove (33), so as to clamp the closing plate between the L-shaped support frame (29) and the first support rod (11).

3. The fire spread test device for wires and cables under a confined structure according to claim 1 is characterized in that: A second support rod (9) is provided at the bottom of the two first support rods (11) in each group of the adjustable mounting brackets. The second support rod (9) is vertically arranged with the first support rod (11). Two third support rods (10) are vertically fixed between the two second support rods (9). The first support rod (11) is slidably connected with the third support rod (10). The tops of the two first support rods (11) in each group of the adjustable mounting brackets are fixed by a fourth support rod (12). A horizontal spacing adjustment mechanism is provided between the first support rods (11) in the two groups of the adjustable mounting brackets. The horizontal spacing adjustment mechanism is used to adjust the horizontal spacing of the first support rods (11) in the two groups of the adjustable mounting brackets.

4. The fire spread test device for simulating electric wires and cables under a confined structure according to claim 3 is characterized in that: The horizontal spacing adjustment mechanism comprises a slider (34) and a second adjustment bolt (35), wherein the slider (34) is fixed on the side wall at the bottom of the first support rod (11), the bottom of the slider (34) is slidably connected to the third support rod (10), the top of the third support rod (10) is provided with a fourth strip-shaped through groove (36) arranged along the length direction thereof, and a through hole for passing the second adjustment bolt (35) is provided on the side wall of the slider (34) facing the fourth strip-shaped through groove (36), and the second adjustment bolt (35) is vertically inserted into the through hole and the fourth strip-shaped through groove (36) to connect the slider (34) to the third support rod (10).

5. The fire spread test device for wires and cables under a confined structure according to claim 4 is characterized in that: One of the vertically arranged closing panels is a glass observation panel (28), and the remaining three closing panels are gypsum panels (25).

6. The fire spread test device for wires and cables under a confined structure according to claim 3 is characterized in that: An inclination adjustment mechanism is provided at the bottom of the two second support rods (9), and the inclination adjustment mechanism comprises a base (13), two support rods (14) and two third adjustment bolts (16). The two support rods (14) are vertically fixed on both sides of the top of the base (13). The two support rods (14) are located outside the two second support rods (9), and the two support rods (14) are connected to the two second support rods (9) respectively by two third adjustment bolts (16).

7. According to the experimental device for simulating the spread of fire of electric wires and cables under a confined structure as described in claim 6, a protractor (15) is fixed on the bottom side wall of the second support rod (9), a hole groove is provided at the center of the horizontal side of the protractor (15), and the protractor (15) is rotatably connected to the third adjusting bolt (16) through the hole groove.

8. A fire spread test device for wires and cables under a confined structure according to any one of claims 1 to 7, characterized in that: The left and right sides of the restricted model body (4) are respectively provided with cable spacing adjustment brackets, and the cable spacing adjustment brackets include a supporting slide rail (27) and a plurality of cable brackets (26). The supporting slide rail (27) is vertically arranged, and the plurality of cable brackets (26) are arranged perpendicular to the slide rail (27) and are slidably connected to the supporting slide rail (27). Each cable bracket (26) is provided with a cable clamp for fixing the cable.

9. The fire spread test device for wires and cables under a confined structure according to claim 8, characterized in that: Also includes: A wind tunnel (1) having a fairing section (2) and an experimental section (3), wherein the restricted model body (4) is arranged in the experimental section (3); An image acquisition system (5) is arranged on a side close to the glass observation plate (28) and is used to record the entire flame diffusion process and temperature field changes during flame combustion in a confined space; Temperature acquisition system, used to record the temperature of wires and cables when they are burning; A blowing system is arranged in the wind tunnel (1) and is used to provide wind speeds of different magnitudes to simulate the combustion characteristics of a flame in a windy environment; Ignition system, used to ignite wires and cables; The central control system (6) is electrically connected to the image acquisition system (5), the temperature acquisition system, the blowing system and the ignition system respectively.

10. An experimental method for simulating fire spread of wires and cables under a confined structure according to claim 9, characterized in that: The following steps are involved: Installing gypsum boards (25) on the upper and lower rear sides of the restricted model body (4) respectively, and installing a glass observation panel (28) on the front side of the restricted model body (4); Place the blowing system at the experimental location and adjust the wind speed of the blowing system to provide the required experimental wind speed; Debugging an image acquisition system and setting the image acquisition system on a side close to the glass observation plate (28) to record the entire flame diffusion process and temperature field changes during flame combustion in a confined space; A temperature acquisition system is installed on the front and rear sides of the restricted model body (4) to record the temperature of the wires and cables when they are burning; Arrange cables on the restricted model body (4), and adjust the size of the restricted space, the degree of restricted enclosure, the spacing of the wires and cables, the wind speed, and the inclination angle of the restricted model body (4) according to the experimental requirements; The ignition system is used to ignite the wires and cables, and the flame gradually spreads. The image acquisition system is used to capture the internal combustion conditions of the restricted model body (4). When the wires and cables are completely burned, the experiment ends.

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