Fire resistance test device and test method for cable trench cover sealing measures

Abstract

The present invention discloses a fire resistance performance test device and test method for cable trench cover closure measures, including an oil pool, a fire extinguishing device, an experimental box, an oil pan, an oil delivery device, and an image acquisition device. The oil pan leads to the experimental box, and the experimental box includes a bottom plate and a side wall located around the bottom plate. A through hole that passes through the bottom plate is arranged on the bottom plate, a protrusion higher than the bottom plate is arranged on the edge of the through hole, and an oil flow port is arranged on the side wall. The method includes: laying the cable trench cover, applying a load, installing a cotton pad and a temperature acquisition device, inputting transformer oil into the oil pan, igniting the oil pan, simulating flowing fire, testing fire resistance and heat insulation, fire resistance integrity, load-bearing capacity, appearance, sealing, etc. during the experiment, and recording the experimental time; and extinguishing the fire on the experimental site after the experiment. The advantages of the present invention are: it can simulate the transformer oil flowing fire scene, test the fire resistance of the cable trench cover and the gap plugging, evaluate its load-bearing, integrity and thermal insulation performance, provide a selection basis for selection, and avoid the expansion of fire accidents.

Description

Technical Field

[0001] The present invention relates to the field of disaster prevention and reduction of power transmission and transformation equipment, and in particular to a fire resistance performance testing device and a testing method for cable trench cover sealing measures. Background Art

[0002] The cable trench cover is a component used to be laid on the cable trench to protect the cable. For example, the Chinese utility model patent with the publication number CN201490671U discloses a cable trench cover, which includes a cover support with upper and lower openings, and a plurality of covers that are detachably mounted on the cover support along the length direction of the cover support and completely cover the opening of the cover support. Each of the covers includes an upper plate portion, a lower plate portion that is parallel to the upper plate portion and fixedly arranged below the upper plate portion in an offset manner, and two adjacent covers are spliced ​​in a zigzag seam. It changes the traditional straight seam splicing of the cable cover to a zigzag seam splicing, and a water diversion trough is provided to discharge rainwater, oil and other flammable liquids that invade the gap of the cable trench cover from the trench, thereby achieving a waterproof and fireproof effect. The cable trench cover of the substation is mostly laid in a spliced ​​manner, which is used to separate the cables in the trench from the substation ground and bear the road surface pressure. Affected by the construction process, there are gaps between the covers, which do not have the ability to prevent the penetration of liquids such as water and oil. When a transformer catches fire, the internal transformer oil leaks, and the high-temperature hot oil fire passes through the nearby cable trench and flows into the trench through the gaps, igniting the cables, causing the fire to spread and the accident to expand. In order to improve the fire safety level of the substation cable trench, substations currently use slot-type cable trench covers, cement mortar plastering, and fiberglass fireproof cloth to seal the gaps, but there is currently no unified standard to judge the advantages and disadvantages of such gap sealing methods. Summary of the invention

[0003] The purpose of the present invention is to provide a cable trench cover sealing measure fire resistance performance test device and test method, simulate the transformer oil flow fire scene, test the cable trench cover and gap plugging fire resistance, evaluate its load-bearing, integrity and thermal insulation performance, provide selection basis for selection, and avoid the expansion of fire accidents.

[0004] The present invention solves the above technical problems through the following technical means: a fire resistance performance testing device for cable trench cover sealing measures, comprising an oil pool, and a fire extinguishing device is arranged on the side wall of the oil pool;

[0005] An experimental box and an oil pan are set up above the oil pool, and an oil delivery device leading to the oil pan is also included. The oil delivery device can deliver transformer oil to the oil pan. The oil pan leads to the experimental box, and the transformer oil in the oil pan can flow into the experimental box.

[0006] The experimental box comprises a bottom plate and a side wall around the bottom plate, the bottom plate is provided with a through hole extending vertically, a protrusion higher than the bottom plate is provided at the edge of the through hole, and an oil flow port is provided on the side wall;

[0007] It also includes an image acquisition device whose field of view covers above the oil pool and the bottom of the experimental box.

[0008] When the cable trench cover sealing measure fire resistance performance test device in the present invention is actually applied, first, the image acquisition device is debugged to ensure normal operation, and all the images are output to an external monitor; the cable trench cover to be tested is laid on the protrusion to cover the through hole; a load is applied to the fire-exposed surface of the cable trench cover; a cotton pad is installed on the back fire surface of the cable trench cover, and the cotton pad is located at the gap between two adjacent cable trench covers; temperature acquisition devices are installed on the back fire surface and the fire-exposed surface of the cable trench cover respectively, and the temperature acquisition devices are located at the center of each cable trench cover and in the middle of the joint of two adjacent cable trench covers; after a certain amount of transformer oil is input into the oil pan through the oil delivery device, the transformer oil in the oil pan is ignited. When the fire on the surface of the oil pan is large enough and the oil temperature has been heated to 70 - 80 °C, the oil delivery device is turned on, and transformer oil is continuously injected into the oil pan. The oil fire flows from the oil pan into the experimental box, and after passing through the cable trench cover, it flows out from the oil flow outlet to simulate the flowing fire; the flow rate of the oil flowing into the oil pan through the oil delivery device is detected and recorded at regular intervals; the situation of the oil pool fire falling is observed, and the fire extinguishing device is intermittently turned on to extinguish the fire according to the overall fire size; during the experiment, the fire resistance insulation, fire resistance integrity, load-bearing capacity, appearance, and sealing performance of the cable trench cover and the gap sealing treatment method are tested. The above device can simulate the scenario of transformer oil flowing fire, test the fire resistance performance of the cable trench cover and the gap sealing, evaluate its load-bearing, integrity, and heat insulation performance, provide a basis for selection, and avoid the expansion of fire accidents. The present invention designs a cable trench cover sealing measure fire resistance performance test device, which can simulate the real environment at the substation site and test the load-bearing, integrity, and heat insulation performance of the cable trench cover under the action of fire. The present invention uses the oil delivery device to control the oil consumption speed and real-time simulates two scenarios: the transformer oil fire spreads and flows over the cable trench cover and the transformer oil on the cable trench cover continues to burn, which conforms to the process of fire occurrence.

[0009] Optimally, an oil discharge pipeline is arranged at the bottom of the oil pool, and the oil discharge pipeline leads to the outside.

[0010] The oil discharge pipeline can smoothly discharge the oil falling into the oil pool, prevent the further expansion of the fire in the oil pool, and at the same time can collect the flowing oil.

[0011] Optimally, the fire extinguishing device includes a water spray system arranged on the side wall of the oil pool.

[0012] Optimally, an experimental box base is arranged in the oil pool. The experimental box base includes a lower base arranged in the oil pool and an upper base arranged on the lower base. The cross-sectional shape of the upper base is in the shape of a "匚".

[0013] The through hole is rectangular, and the experimental box is arranged on the top of the upper base, and the width of the through hole is the same as the opening width of the upper base.

[0014] Setting the cross-sectional shape of the upper base to a U-shape and arranging the experimental box on the top of the upper base can effectively expose the bottom of the experimental box from below, thereby facilitating observation and conducting relevant experiments.

[0015] Optimally, two right-angle connectors are arranged at the bottom of the experimental box. The two right-angle connectors are distributed oppositely on both sides of the through hole, and both sides of the right-angle connectors are respectively installed on the bottom of the experimental box and two opposite inner walls of the upper base.

[0016] Optimally, the orientation of the oil outlet is on the side opposite to the side opening of the upper base.

[0017] In practical applications, the burning transformer oil will flow out from the oil outlet. Setting the oil outlet to be on the side opposite to the side opening of the upper base can prevent the oil fire from falling onto the bottom of the experimental box, so as not to affect the progress of the experiment.

[0018] Optimally, the image acquisition device includes a first camera arranged on the side of the oil pool and a second camera arranged on the lower base. The second camera is located below the through hole.

[0019] The first camera can observe and record the fire situation of the oil pool in real time, while the second camera can observe the situation at the bottom of the experimental box.

[0020] Optimally, the top surface of the oil pan is higher than the top surface of the experimental box. The oil pan is communicated with the experimental box through an oil groove. The cross-sectional shape of the oil groove is U-shaped, and a first valve for controlling the flow rate is arranged in the oil groove.

[0021] The transformer oil burns in the oil pan and then flows into the experimental box through the oil groove to simulate the oil fire from the transformer. The first valve can adjust the flow rate in the oil groove.

[0022] Optimally, the oil delivery device includes an oil tank, an oil delivery pipe, and an oil pump; the inlet of the oil pump is communicated with the oil tank through the oil delivery pipe, and the outlet of the oil pump leads to the oil pan through the oil delivery pipe.

[0023] By controlling the operation of the oil pump, the flow rate of the transformer oil from the oil tank into the oil pan can be controlled.

[0024] The present invention also discloses a test method for a fire resistance performance test device adopting the above cable trench cover plate closing measures, including the following steps:

[0025] s1. Debug the image acquisition device to ensure normal operation, and output all the images to an external display.

[0026] s2. Lay the cable trench cover to be tested on the protrusion to cover the through hole;

[0027] s3. Apply load on the fire-exposed surface of the cable trench cover;

[0028] s4. Install cotton pads on the back side of the cable trench cover, and the cotton pads are located in the gap between two adjacent cable trench covers;

[0029] A temperature collection device is installed on the non-fire surface and the fire-exposed surface of the cable trench cover, respectively. The temperature collection device is located at the center of each cable trench cover and in the middle of the joint of two adjacent cable trench covers;

[0030] s5. After a certain amount of transformer oil is input into the oil pan through the oil delivery device, the transformer oil in the oil pan is ignited. When the fire on the surface of the oil pan is large enough and the oil temperature has been heated to 70-80℃, the oil delivery device is turned on to continuously inject transformer oil into the oil pan. The oil fire flows from the oil pan into the experimental box, and then flows out from the oil outlet after passing through the cable trench cover, simulating a flowing fire.

[0031] s6. Detect and record the flow rate flowing into the oil pan through the oil delivery device at regular intervals;

[0032] s7. Observe the fire situation in the oil pool and intermittently activate the fire extinguishing device to extinguish the fire according to the overall size of the fire;

[0033] s8. The following tests were performed during the experiment:

[0034] A. Fire resistance and thermal insulation:

[0035] During the experiment, the temperature data of the back-fire surface of the cable trench cover was measured by a temperature acquisition device. The measurement time interval did not exceed 1 minute. The loss of thermal insulation of the cable trench cover and the gap plugging was determined according to the following criteria:

[0036] A1) The average temperature of the back-fired surface exceeds the initial temperature by 140°C;

[0037] A2) Any point on the back-fired surface exceeds the initial temperature by 180°C;

[0038] A3) Any point in the gap exceeds the average temperature of the back-fire surface of the cable trench cover by 40°C;

[0039] B. Fire resistance integrity:

[0040] The loss of thermal insulation due to gap sealing is determined according to the following criteria:

[0041] B1) Cracks with a total length of not less than 150mm appear on the back-fired surface of the cable trench cover;

[0042] B2) The cotton pad was observed to be ignited;

[0043] B3) A flame is observed at the gap and lasts for more than 10 seconds;

[0044] C. Carrying capacity:

[0045] Before the cable trench cover is loaded and after loading as required, during the test, the deformation is measured once in the middle of the cable trench cover at intervals of 1 minute. The loss of bearing capacity is determined according to the following criteria:

[0046] C1) The cable trench cover is broken or collapsed;

[0047] C2) The maximum deformation of the cable trench cover reaches the limit bending deformation: Where L is the clear span of the cable trench cover, and d is the half value of the clear span of the cable trench cover;

[0048] D. Appearance:

[0049] Observe the cable trench cover and gaps to see if there are any signs of deformation, cracking, powdering or burning;

[0050] E. Sealing:

[0051] Observe that the fire extinguishing medium enters the back-fire surface of the cable trench cover from the gap of the cable trench cover and lasts for more than 10 seconds;

[0052] The above-mentioned fire resistance and heat insulation, fire resistance integrity are used as decisive indicators. If there are unqualified items, it is considered that this type of cable trench cover and gap plugging treatment method are unqualified; bearing capacity, appearance, and sealing are used as general indicators. If there are more than 2 unqualified items, it is considered that this type of cable trench cover and gap plugging treatment method are unqualified;

[0053] s9. After completing the test in s8, terminate the experiment and record the experimental time; after the experiment, turn on the fire extinguishing device to extinguish the fire in the experimental site.

[0054] Through the above method, the transformer oil flow fire scene can be simulated, the fire resistance of the cable trench cover and the gap plugging can be tested, and its load-bearing, integrity and thermal insulation performance can be evaluated, providing a selection basis for the selection and avoiding the expansion of fire accidents. The present invention uses the hierarchical analysis method to conduct a comprehensive analysis of the performance indicators of the cable trench cover and the gap plugging, and the evaluation results are closer to the actual needs.

[0055] The advantages of the present invention are:

[0056] 1. When the cable trench cover plate sealing measure fire resistance performance test device in the present invention is actually applied, first, the image acquisition device is debugged to ensure normal operation, and all images are output to an external monitor; the cable trench cover plate to be tested is laid on the protrusion to cover the through hole; a load is applied to the fire-exposed surface of the cable trench cover plate; a cotton pad is installed on the back fire surface of the cable trench cover plate, and the cotton pad is located at the gap between two adjacent cable trench cover plates; temperature acquisition devices are installed on the back fire surface and the fire-exposed surface of the cable trench cover plate respectively, and the temperature acquisition devices are located at the center of each cable trench cover plate and in the middle of the joint of two adjacent cable trench cover plates; after a certain amount of transformer oil is input into the oil pan through the oil delivery device, the transformer oil in the oil pan is ignited. When the fire on the surface of the oil pan is large enough and the oil temperature has been heated to 70 - 80 °C, the oil delivery device is started, and transformer oil is continuously injected into the oil pan. The oil fire flows from the oil pan into the experimental box, and after passing through the cable trench cover plate, it flows out from the oil outlet, simulating the flowing fire; the flow rate of the oil flowing into the oil pan through the oil delivery device is detected and recorded at regular intervals; the situation of the oil pool fire falling is observed, and the fire extinguishing device is intermittently started to extinguish the fire according to the overall fire size; during the experiment, the fire resistance insulation, fire resistance integrity, bearing capacity, appearance, and sealing performance of the cable trench cover plate and the gap sealing treatment method are tested. The above device can simulate the scenario of transformer oil flowing fire, test the fire resistance performance of the cable trench cover plate and the gap sealing, evaluate its bearing, integrity, and heat insulation performance, provide a basis for selection, and avoid the expansion of fire accidents. The present invention designs a cable trench cover plate sealing measure fire resistance performance test device, which can simulate the real environment of a substation site and test the bearing, integrity, and heat insulation performance of the cable trench cover plate under the action of fire. The present invention uses the oil delivery device to control the oil consumption speed and real-time simulates two scenarios: the spread and flow of transformer oil fire over the cable trench cover plate and the continuous combustion of transformer oil on the cable trench cover plate, which conforms to the process of fire occurrence.

[0057] 2. The oil drainage pipeline can smoothly drain the oil falling into the oil pool, prevent the further expansion of the fire in the oil pool, and at the same time can collect the flowing oil.

[0058] 3. The cross-sectional shape of the upper base is set as a U-shaped, and the experimental box is set on the top of the upper base, which can effectively expose the bottom of the experimental box from below, thus facilitating observation and carrying out relevant experiments.

[0059] 4. In actual application, the burning transformer oil will flow out from the oil outlet. The oil outlet is set on the side opposite to the side opening of the upper base, which can prevent the oil fire from falling to the bottom of the experimental box and affecting the progress of the experiment.

[0060] 5. The first camera can observe and record the fire situation of the oil pool in real time, while the second camera can observe the situation at the bottom of the experimental box.

[0061] 6. The transformer oil burns in the oil pan and then flows into the experimental box through the oil tank, simulating an oil fire from the transformer. The first valve can adjust the flow rate in the oil tank.

[0062] 7. By controlling the operation of the oil pump, the flow of transformer oil from the oil tank through the oil pipe into the oil pan can be controlled.

[0063] 8. Through the above method, the transformer oil flow fire scene can be simulated, the fire resistance of the cable trench cover and the gap plugging can be tested, and its load-bearing, integrity and thermal insulation performance can be evaluated, providing a basis for selection and avoiding the expansion of fire accidents. The present invention uses the hierarchical analysis method to conduct a comprehensive analysis of the performance indicators of the cable trench cover and the gap plugging, and the evaluation results are closer to the actual needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 Schematic diagram of a fire resistance performance testing device for cable trench cover sealing measures in an embodiment of the present invention;

[0065] Figure 2-4 It is a stereoscopic diagram of the experimental box at different viewing angles in an embodiment of the present invention;

[0066] Figure 5 , 6 They are respectively a front view and a left view of the experimental box in an embodiment of the present invention;

[0067] Figure 7 is a three-dimensional diagram of the experimental box in an embodiment of the present invention (without the right-angle connector);

[0068] in,

[0069] Oil pool-1, oil drainage pipeline-11, water spray system-12;

[0070] Experiment box-2, bottom plate-21, side wall-22, through hole-23, protrusion-24, oil flow port-25;

[0071] Oil pan-3, oil pan base-31;

[0072] Oil delivery device-4, oil tank-41, oil delivery pipe-42, oil pump-43, second valve-44;

[0073] Experiment box base-5, upper base-51, lower base-52;

[0074] Right angle connector-6;

[0075] First camera-71, second camera-72;

[0076] Oil tank-8, first valve-81. DETAILED DESCRIPTION

[0077] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0078] Embodiment 1:

[0079] As Figure 1 shown, a fire resistance performance test device for cable trench cover closing measures includes an oil pool 1, an experimental box 2, an oil pan 3, an oil delivery device 4, an experimental box base 5, a right-angle connector 6, an image acquisition device, and an oil trough 8.

[0080] As Figure 1 shown, the oil pool 1 is opened on the ground and is a rectangular parallelepiped pool. A fire extinguishing device is provided on the side wall of the oil pool 1. The fire extinguishing device includes a water spray system 12 arranged on the side wall of the oil pool 1. The water spray system 12 includes nozzles installed on the side wall of the oil pool 1. The nozzles are connected to an external water source or other fire extinguishing medium sources. The number, position, and spraying direction of the nozzles are set according to actual test requirements, and it is sufficient to meet the requirement of spraying and extinguishing the oil pool 1, the experimental box 2, and the oil pan 3. The capacity of the oil pool 1 should be not less than twice the amount of oil used in the experiment.

[0081] As Figure 1 shown, an oil discharge pipeline 11 is provided at the bottom of the oil pool 1. The oil discharge pipeline 11 leads to the outside, such as to an external accident oil collection pool.

[0082] As Figure 1 shown, the experimental box 2 and the oil pan 3 are erected above the oil pool 1. An oil delivery device 4 leading to the oil pan 3 is further included. The oil delivery device 4 can transport transformer oil to the oil pan 3. The oil pan 3 leads to the experimental box 2, and the transformer oil in the oil pan 3 can flow into the experimental box 2.

[0083] As Figure 1 shown, the top surface of the oil pan 3 is higher than the top surface of the experimental box 2. The oil pan 3 and the experimental box 2 are connected through an oil trough 8. The oil trough 8 is made of non-magnetic stainless steel. A flowing transformer oil fire is formed by using the height difference. The cross-sectional shape of the oil trough 8 is U-shaped. The cross-sectional width of the oil trough 8 is 500 mm. The horizontal projection length of the oil trough 8 is 1700 mm, and the vertical drop is 100 mm.

[0084] As Figure 1As shown in the figure, a first valve 81 for controlling the flow rate is provided in the oil tank 8, which can adjust the oil flow rate and control the flow of the oil fire. The first valve 81 is an electric gate, and the electric gate is a prior art. The installation of the electric gate should meet the requirement that when the gate is closed, the transformer oil does not cross the gate, thereby playing a closing role. Preferably, the electric gate can be installed at the connection position between the oil tank 8 and the oil pan 3.

[0085] As Figure 2-7 shown, the experimental box 2 is integrally in a cubic structure and is made of a composite fireproof board. The inner layer of the composite fireproof board is a fireproof rock wool board, and the outer layer is wrapped with a non-magnetic stainless steel plate with a thickness of not less than 0.5 mm.

[0086] As Figure 2 shown, the experimental box 2 includes a bottom plate 21 and side walls 22 surrounding the bottom plate 21. A through hole 23 penetrating up and down is provided on the bottom plate 21, and a protrusion 24 higher than the bottom plate 21 is provided at the edge of the through hole 23. The protrusion 24 is used to simulate the groove wall. The protrusion 24 is in a square shape, the single-side width of the protrusion 24 is 50 mm, and the height of the protrusion 24 relative to the bottom plate 21 is 50 mm. The protrusion 24 is used to lap the cable trench cover plate to simulate the gap between the cable trench cover plate and the groove wall. An oil flow port 25 is provided on the side wall 22.

[0087] The length, width and height of the experimental box 2 are 2200 mm × 2000 mm × 175 mm respectively. For the convenience of description, taking the Figure 1 viewpoint in the figure as the main view direction, the left-right direction of the experimental box 2 is the length direction, the thickness of the bottom plate 21 is 70 mm, the oil flow port 25 is opened in the middle of the left-end side wall 22, the cross-sectional shape of the oil flow port 25 is U-shaped, and the depth of the oil flow port 25 is 5 mm.

[0088] As Figure 2 shown, the through hole 23 is a square hole, the size of the square hole is 1000 mm × 1500 mm, and the length direction of the square hole is parallel to the length direction of the experimental box 2.

[0089] As Figure 1 shown, an experimental box base 5 is provided in the oil pool 1. The experimental box base 5 includes a lower base 52 provided in the oil pool 1 and an upper base 51 provided on the lower base 52. The cross-sectional shape of the upper base 51 is in a C shape; the through hole 23 is rectangular, the experimental box 2 is provided on the top of the upper base 51, and the width of the through hole 23 is the same as the opening width of the upper base 51. Both the upper base 51 and the lower base 52 are made of concrete.

[0090] As Figure 3 、 6As shown, two right-angle connectors 6 are arranged at the bottom of the experimental box 2. The right-angle connectors 6 are made of demagnetized stainless steel. The right-angle connectors 6 include two vertical plates with the same shape as angle irons, and can also be made of angle irons. Mounting holes are provided on both sides of the right-angle connectors 6. The two right-angle connectors 6 are relatively distributed on both sides of the through hole 23. The two sides of the right-angle connectors 6 are respectively installed on the bottom of the experimental box 2 and the two opposite inner walls of the upper base 51 by screws. The oil flow port 25 faces the side opposite to the lateral opening of the upper base 51.

[0091] In addition, a transverse groove may be provided on the side wall of the long side of the through hole 23 , and one side of the right-angle connector 6 may be inserted into the groove, and then screwed in to fix it to the bottom of the experimental box 2 .

[0092] like Figure 1 As shown, the oil delivery device 4 includes an oil tank 41, an oil delivery pipe 42, and an oil pump 43; the oil inlet of the oil pump 43 is connected to the oil tank 41 through the oil delivery pipe 42, and the oil discharge port of the oil pump 43 is connected to the oil pan 3 through the oil delivery pipe 42. The oil tank 41 contains transformer oil for the experiment, the oil pump 43 can control the oil discharge speed, and the oil delivery pipe 42 is a hose.

[0093] Further, such as Figure 1 As shown, a second valve 44 and a flow meter are provided on the oil pipeline 42 between the oil pump 43 and the oil pan 3 . The second valve 44 is used to control the flow rate, such as by using a flow control valve, and the flow meter is used to detect the flow rate of oil in the oil pipeline 42 .

[0094] The oil pan 3 is a rectangular pool with an opening facing upward, made of demagnetized stainless steel, with a size of 3000mm×1000mm×200mm, and is used to store ignited transformer oil and to simulate oil fire coming from the transformer direction.

[0095] like Figure 1 As shown, an oil pan base 31 made of concrete is provided in the oil pool 1 , and the oil pan 3 is placed on top of the oil pan base 31 .

[0096] Further, such as Figure 1 As shown, flame retardant and fireproofing materials are also laid between the side wall of the oil pool 1 and the lower base 52 and the oil pan base 31. In this embodiment, the flame retardant and fireproofing materials are pebbles, which are laid in the oil pool 1 to facilitate the infiltration of the transformer and fireproofing and flame retardancy.

[0097] The field of view of the image acquisition device covers the top of the oil pool 1 and the bottom of the experimental box 2. Figure 1 As shown, the image acquisition device includes a first camera 71 arranged at the side of the oil pool 1 and a second camera 72 arranged on the lower base 52 , and the second camera 72 is located below the through hole 23 .

[0098] Further, such as Figure 1 As shown, the first camera 71 is located on the left side of the oil pool 1, and the first camera 71 and the second camera 72 are both placed in corresponding fireproof boxes (not shown in the figure). The fireproof box is a cubic box structure, and the box body is made of fireproof partitions, wherein the box plate in the shooting direction of the camera lens is made of fireproof glass.

[0099] Furthermore, it also includes a control unit. The control unit in this embodiment adopts PLC. PLC is a prior art. Those skilled in the art can program it according to actual needs to realize the control function described in this embodiment. The water sprinkler system 12, oil pump 43, second valve 44, first camera 71, second camera 72, and first valve 81 are all controlled by the control unit. The thermocouple, flow meter, first camera 71, and second camera 72 are connected to the control unit to transmit the detection data or the captured image to the control unit.

[0100] Working principle:

[0101] like Figure 1As shown, when the fire resistance performance test device for the cable trench cover closing measure in the present invention is actually applied, first, the image acquisition device is debugged to ensure normal operation, and all the images are output to an external display; the cable trench cover to be tested is laid on the protrusion 24 to cover the through hole 23; a load is applied to the fire-exposed surface of the cable trench cover; a cotton pad is installed on the back fire surface of the cable trench cover, and the cotton pad is located at the gap between two adjacent cable trench covers; temperature acquisition devices are respectively installed on the back fire surface and the fire-exposed surface of the cable trench cover, and the temperature acquisition devices are located at the center of each cable trench cover and in the middle of the joint of two adjacent cable trench covers; after a certain amount of transformer oil is input into the oil pan 3 through the oil delivery device 4, the transformer oil in the oil pan 3 is ignited. When the fire on the surface of the oil pan 3 is large enough and the oil temperature has been heated to 70 - 80 °C, the oil delivery device 4 is started, and transformer oil is continuously injected into the oil pan 3. The oil fire flows from the oil pan 3 into the experimental box 2, and after passing through the cable trench cover, it flows out from the oil outlet 25 to simulate the flowing fire; the flow rate of the oil flowing into the oil pan 3 through the oil delivery device 4 is detected and recorded at regular intervals; the fire falling situation of the oil pool 1 is observed, and the fire extinguishing device is intermittently started to extinguish the fire according to the overall fire intensity; during the experiment, the fire resistance insulation, fire resistance integrity, bearing capacity, appearance, and sealing performance of the cable trench cover and the gap sealing treatment method are tested. The above device can simulate the scenario of transformer oil flowing fire, test the fire resistance performance of the cable trench cover and the gap sealing, evaluate its bearing, integrity, and heat insulation performance, provide a basis for selection, and avoid the expansion of fire accidents. The present invention designs a fire resistance performance test device for the cable trench cover closing measure, which can simulate the real environment of the substation site and test the bearing, integrity, and heat insulation performance of the cable trench cover under the action of fire. The present invention uses the oil delivery device to control the oil consumption speed and real-time simulates two scenarios: the transformer oil fire spreads and flows over the cable trench cover and the transformer oil on the cable trench cover continues to burn, which conforms to the process of fire occurrence.

[0102] The oil drainage pipeline 11 can smoothly drain the oil falling into the oil pool 1, prevent the further expansion of the fire in the oil pool 1, and at the same time can collect the flowing oil. The cross-sectional shape of the upper base 51 is set to be U-shaped, and the experimental box 2 is set on the top of the upper base 51, which can effectively expose the bottom of the experimental box 2 from below, thus facilitating observation and carrying out relevant experiments. In actual application, the burning transformer oil will flow out from the oil outlet 25. The oil outlet 25 is set to face the side opposite to the side opening of the upper base 51, which can prevent the oil fire from falling to the bottom of the experimental box 2 and affecting the progress of the experiment. The first camera 71 can observe and record the fire situation of the oil pool 1 in real time, and the second camera 72 can observe the situation at the bottom of the experimental box 2. The transformer oil burns in the oil pan 3 and then flows into the experimental box 2 through the oil groove 8 to simulate the oil fire from the transformer. The first valve 81 can adjust the flow rate in the oil groove 8. By controlling the operation of the oil pump 43, the flow rate of the transformer oil from the oil tank 41 through the oil pipeline 42 into the oil pan 3 can be controlled.

[0103] Embodiment 2:

[0104] The present invention also discloses a testing method for the fire resistance performance testing device using the cable trench cover sealing measure, comprising the following steps:

[0105] s1. Debug the image acquisition device to ensure normal operation and output all images to the display of the peripheral device; inject transformer oil into the oil tank 41 and fix the oil tank 41 to prevent swinging during the experiment; dry the cable trench cover to be tested and pre-treat it to a temperature and humidity equilibrium state. According to the type of cable trench cover, select the corresponding sealing measures. The sealing measures are the existing technology for sealing different cable trench covers. They can be selected according to the type of cable trench cover. In this embodiment, three cable trench covers are combined into one test piece for the experiment, and the three cable trench covers are spliced ​​together side by side in sequence;

[0106] s2. Lay the cable trench cover to be tested on the protrusion 24 to cover the through hole 23;

[0107] s3. Apply a load on the fire-exposed surface of the cable trench cover. In this embodiment, a weight is placed on the top of the cable trench cover to apply the load. The size and position of the applied load are set according to the test requirements. In this embodiment, a test load of 10 kN / m2 is uniformly loaded on the fire-exposed surface of the specimen.

[0108] s4. Install cotton pads on the non-fire side of the cable trench cover, and the cotton pads are located at the gap between two adjacent cable trench covers; specifically, the cotton pads are the cotton pads in GB T 9978.1-2008 Fire resistance test method for building components, and the cotton pads are installed at the bottom of the gap between two adjacent cable trench covers to block the gap. Specifically, the cotton pads can be installed at the bottom of the gap by screw installation, bonding or other installation methods, and the cotton pads should block all gaps between two adjacent cable trench covers;

[0109] In addition, according to the test requirements, a cotton pad can be installed on the inner side of the joint between the cable trench cover and the protrusion 24, that is, the inner side of the square frame-shaped protrusion 24, to block the joint between the cable trench cover and the protrusion 24;

[0110] A temperature collection device is installed on the non-fire surface and the fire-receiving surface of the cable trench cover. The temperature collection device adopts a thermocouple. The temperature collection device is located at the center of each cable trench cover and in the middle of the joint of two adjacent cable trench covers. The middle here refers to the middle of the length direction of the joint, including the top middle and the bottom middle of the joint;

[0111] In addition, according to the test requirements, a thermocouple can also be set in the middle of the joint between the cable trench cover and the protrusion 24, where the middle refers to the middle of the length direction of the joint, and the thermocouple here is located on the side of the protrusion 24 and the bottom of the cable trench cover;

[0112] A micro-deformation measuring instrument is installed on the non-fire surface of the test piece to detect the deformation of the cable trench cover. The micro-deformation measuring instrument and its installation and detection methods are existing technologies.

[0113] s5. After a certain amount of transformer oil is input into the oil pan 3 through the oil delivery device 4, cotton yarn is put into the oil pan 3 to ensure that the fire continues to be large enough and the transformer oil in the oil pan 3 is preheated in advance. 200 ml of gasoline is injected into the oil pan 3 as a transformer oil igniter, and a torch is used to ignite the gasoline injected into the oil pan 3, and the transformer oil in the oil pan 3 is ignited by the gasoline;

[0114] The size of the fire on the surface of the oil pan 3 is determined according to the test requirements. If the test requirements are met, the oil pan 3 surface fire is large enough and the oil temperature has been heated to 70-80°C. The oil delivery device 4 is turned on. Specifically, the oil pump 43 is turned on, the second valve 44 is opened, and transformer oil is continuously injected into the oil pan 3. The oil fire flows from the oil pan 3 into the experimental box 2, and the oil fire flows out from the oil flow port 25 after passing through the cable trench cover, simulating a flowing fire.

[0115] s6. Start timing from the moment the second valve 44 is opened, and detect and record the flow rate flowing into the oil pan 3 through the oil delivery device 4 at regular intervals. The flow rate detection is achieved by a flow meter;

[0116] s7. Observe the fire situation of oil pool 1 and intermittently activate the fire extinguishing device to extinguish the fire according to the overall fire size;

[0117] Specifically, the water sprinkler system 12 is intermittently opened to extinguish the fire according to the size of the fire;

[0118] s8. The following tests were performed during the experiment:

[0119] A. Fire resistance and thermal insulation:

[0120] During the experiment, the temperature data of the back-fire surface of the cable trench cover was measured by a temperature acquisition device. The measurement time interval did not exceed 1 minute. The loss of thermal insulation of the cable trench cover and the gap plugging was determined according to the following criteria:

[0121] A1) The average temperature of the back-fired surface exceeds the initial temperature by 140°C;

[0122] A2) Any point on the back-fired surface exceeds the initial temperature by 180°C;

[0123] A3) Any point in the gap exceeds the average temperature of the back-fire surface of the cable trench cover by 40°C;

[0124] B. Fire resistance integrity:

[0125] The loss of thermal insulation due to gap sealing is determined according to the following criteria:

[0126] B1) Cracks with a total length of not less than 150mm appear on the back-fired surface of the cable trench cover;

[0127] B2) The cotton pad was observed to be ignited;

[0128] B3) A flame is observed at the gap and lasts for more than 10 seconds;

[0129] C. Carrying capacity:

[0130] Before the cable trench cover is loaded and after loading as required, during the test, the deformation is measured once in the middle of the cable trench cover at intervals of 1 minute. The loss of bearing capacity is determined according to the following criteria:

[0131] C1) The cable trench cover is broken or collapsed;

[0132] C2) The maximum deformation of the cable trench cover reaches the limit bending deformation: Where L is the clear span of the cable trench cover, and d is the half value of the clear span of the cable trench cover, that is, d is half of L;

[0133] D. Appearance:

[0134] Observe the cable trench cover and gaps to see if there are any signs of deformation, cracking, powdering or burning;

[0135] E. Sealing:

[0136] Observe that the fire extinguishing medium enters the back-fire surface of the cable trench cover from the gap of the cable trench cover and lasts for more than 10 seconds;

[0137] The above-mentioned fire resistance and heat insulation, fire resistance integrity are used as decisive indicators. If there are unqualified items, it is considered that this type of cable trench cover and gap plugging treatment method are unqualified; bearing capacity, appearance, and sealing are used as general indicators. If there are more than 2 unqualified items, it is considered that this type of cable trench cover and gap plugging treatment method are unqualified;

[0138] s9. After completing the test in s8, terminate the experiment and record the experimental time; after the experiment, open the fire extinguishing device to extinguish the fire in the experimental site, open the fire hydrant at the same time, and use the foam fire extinguisher to extinguish the fire in the experimental site.

[0139] Through the above method, it is possible to simulate the transformer oil flow fire scene, test the fire resistance of the cable trench cover and gap plugging, evaluate its load-bearing, integrity and thermal insulation performance, provide a selection basis for the selection, and avoid the expansion of fire accidents. The present invention designs a cable trench cover closure measures fire resistance test device to simulate the real environment of the substation site, and can test the load-bearing, integrity and thermal insulation performance of the cable trench cover under the action of fire. The present invention uses the oil pump 43 to control the oil speed, and simulates the transformer oil fire spreading through the cable trench cover and the transformer oil on the cable trench cover in real time. The two scenarios of continuous burning are consistent with the fire process. The present invention uses the hierarchical analysis method to comprehensively analyze the performance indicators of the cable trench cover and the gap plugging, and the evaluation results are closer to the actual situation requirements.

[0140] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fire resistance performance testing device for cable trench cover sealing measures, characterized in that: It includes an oil sump (1), and a fire extinguishing device is arranged on the side wall of the oil sump (1); an experimental box (2) and an oil pan (3) are erected above the oil sump (1), and it also includes an oil delivery device (4) leading to the oil pan (3). The oil delivery device (4) can deliver transformer oil to the oil pan (3). The oil pan (3) leads to the experimental box (2), and the transformer oil in the oil pan (3) can flow into the experimental box (2); the experimental box (2) includes a bottom plate (21) and side walls (22) located around the bottom plate (21). A through hole (23) penetrating up and down is arranged on the bottom plate (21), and a protrusion (24) higher than the bottom plate (21) is arranged at the edge of the through hole (23). An oil flow port (25) is arranged on the side wall (22); it also includes an image acquisition device whose visual field range covers above the oil sump (1) and the bottom of the experimental box (2); an oil discharge pipeline (11) is arranged at the bottom of the oil sump (1), and the oil discharge pipeline (11) leads to the outside. The fire extinguishing device includes a water spray system (12) arranged on the side wall of the oil sump (1). An experimental box base (5) is arranged in the oil sump (1). The experimental box base (5) includes a lower base (52) arranged in the oil sump (1) and an upper base (51) arranged on the lower base (52). The cross-sectional shape of the upper base (51) is in the shape of a "匚"; the through hole (23) is rectangular. The experimental box (2) is arranged on the top of the upper base (51), and the width of the through hole (23) is the same as the opening width of the upper base (51). Two right-angle connectors (6) are arranged at the bottom of the experimental box (2). The two right-angle connectors (6) are distributed relatively on both sides of the through hole (23). The two sides of the right-angle connector (6) are respectively installed on the bottom of the experimental box (2) and the two opposite inner walls of the upper base (51). The orientation of the oil flow port (25) is opposite to the side opening of the upper base (51). The image acquisition device includes a first camera (71) arranged on the side of the oil sump (1) and a second camera (72) arranged on the lower base (52). The second camera (72) is located below the through hole (23); the top surface of the oil pan (3) is higher than the top surface of the experimental box (2). The oil pan (3) is communicated with the experimental box (2) through an oil groove (8). The cross-sectional shape of the oil groove (8) is in the shape of "凵", and a first valve (81) for controlling the flow rate is arranged in the oil groove (8). The oil delivery device (4) includes an oil tank (41), an oil delivery pipe (42), and an oil pump (43); the inlet of the oil pump (43) is communicated with the oil tank (41) through the oil delivery pipe (42), and the outlet of the oil pump (43) leads to the oil pan (3) through the oil delivery pipe (42).

2. A test method using the cable trench cover sealing measure fire resistance test device according to claim 1, characterized in that: It includes the following steps: S1. Debug the image acquisition device to ensure normal operation, and output all images to an external display; S2. Lay the cable trench cover plate to be tested on the protrusion (24) to cover the through hole (23); S3. Apply a load to the fire-exposed surface of the cable trench cover plate; S4. Install cotton pads on the fire-protected surface of the cable trench cover plate, and the cotton pads are located at the gaps between adjacent cable trench cover plates; A temperature collection device is installed on the non-fire surface and the fire-exposed surface of the cable trench cover, respectively. The temperature collection device is located at the center of each cable trench cover and in the middle of the joint of two adjacent cable trench covers; s5. After a certain amount of transformer oil is input into the oil pan (3) through the oil delivery device (4), the transformer oil in the oil pan (3) is ignited. When the fire on the surface of the oil pan (3) is large enough and the oil temperature has been heated to 70-80° C., the oil delivery device (4) is opened to continuously inject transformer oil into the oil pan (3). The oil fire flows from the oil pan (3) into the experimental box (2), passes through the cable trench cover plate, and then flows out from the oil flow port (25), simulating a flowing fire. s6. Detecting and recording the flow rate flowing into the oil pan (3) through the oil delivery device (4) at regular intervals; s7. Observe the fire situation in the oil pool (1) and intermittently activate the fire extinguishing device to extinguish the fire according to the overall fire size; s8. The following tests were performed during the experiment: A. Fire resistance and thermal insulation: During the experiment, the temperature data of the back-fire surface of the cable trench cover was measured by a temperature acquisition device. The measurement time interval did not exceed 1 min. The loss of thermal insulation of the cable trench cover and gap plugging was determined according to the following criteria: A1) The average temperature of the back-fired surface exceeds the initial temperature by 140°C; A2) Any point on the back-fired surface exceeds the initial temperature by 180°C; A3) Any point in the gap exceeds the average temperature of the back-fire surface of the cable trench cover by 40°C; B. Fire resistance integrity: The loss of thermal insulation due to gap sealing is determined according to the following criteria: B1) Cracks with a total length of not less than 150mm appear on the back-fired surface of the cable trench cover; B2) The cotton pad was observed to be ignited; B3) A flame is observed at the gap and lasts for more than 10 seconds; C. Carrying capacity: Before the cable trench cover is loaded and after loading as required, during the test, the deformation is measured once every 1 minute in the middle of the cable trench cover. The loss of bearing capacity is determined according to the following criteria: C1) The cable trench cover is broken or collapsed; C2) The maximum deformation of the cable trench cover reaches the limit bending deformation: , where L is the clear span of the cable trench cover, and d is the half value of the clear span of the cable trench cover; D. Appearance: Observe the cable trench cover and gaps to see if there are any signs of deformation, cracking, powdering or burning; E. Sealing: Observe that the fire extinguishing medium enters the back-fire surface of the cable trench cover from the gap of the cable trench cover and lasts for more than 10 seconds; The above-mentioned fire resistance and heat insulation, fire resistance integrity are used as decisive indicators. If there are unqualified items, it is considered that this type of cable trench cover and gap plugging treatment method are unqualified; bearing capacity, appearance, and sealing are used as general indicators. If there are more than 2 unqualified items, it is considered that this type of cable trench cover and gap plugging treatment method are unqualified; s9. After completing the test in s8, terminate the experiment and record the experimental time; after the experiment, turn on the fire extinguishing device to extinguish the fire in the experimental site.

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