A device and method for evaluating the operating status of cable fire retardant coating

Abstract

The present invention provides a device and method for evaluating the operating status of a cable fire retardant coating. The device includes: a test box including: a test area and a control area; a cable test piece placed at a preset test position in the test area; a power supply system including three phases and a center line, the three phases and the center line being connected to the cable test piece; a bracket erected at a preset support position in the test area; an environmental simulation system including a temperature control module, a humidity control module, and a spray pipe, the temperature control module and the humidity control module being installed in the control area, and the humidity control module being connected to the spray pipe; a fault simulation system including: a pressing rod, a first force-bearing rod, and a second force-bearing rod, the shaft ends of which are connected to a rotating bearing, a support rod connecting the pressing rod and the first force-bearing rod, a protrusion formed at the pressed-in end of the first force-bearing rod, and a protrusion position of the protrusion being arranged relative to a notch of the second force-bearing rod. The present invention solves the technical problems of test parameters being out of touch with reality, unreasonable setting of flame retardant performance criteria, and a single test scenario.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission and transformation equipment, and in particular to a device and method for evaluating the operating status of cable fire retardant coatings. Background Art

[0002] According to the existing definition in "Cable Fire Retardant Coatings GB 28374-2012," cable fire retardant coatings are applied to the surface of cables to provide fire retardant protection and a decorative effect. However, existing technologies fail to assess whether fire retardant coatings have lost their fire protection capabilities after long-term operation in cable channels. The existing invention patent document "Performance Evaluation and Detection Method and System for Cable Fire Retardant Coatings after Operation" with publication number CN112394083A, includes the following steps: Step 1, collecting coating on a cable coated with an expandable cable fire retardant coating after operation, recorded as the operation group, and collecting the unaged coating of the cable sample, recorded as the control group; Step 2, performing state adjustment in a state adjustment room, and then drying the coating sample and cooling it to room temperature; weighing the coating sample obtained with a set weight, placing it in a muffle furnace, and taking it out and cooling it after a set time; Step 3, pressing the coating sample obtained in Step 2 into powder; measuring the volume of the obtained coating sample, calculating the expansion ratio of the coatings in the operation group and the control group, and then calculating the expansion ratio ratio of the coatings in the operation group and the control group; Step 4, comparing the expansion ratio ratio with the cable fire retardant coating failure criterion to determine whether the cable fire retardant coating has failed at the time of sampling. However, the following issues remain: 1) The test parameters for simulating aging of cable fire retardant coatings do not conform to the actual on-site environment of cable channels; 2) Relying on the expansion ratio of the fire retardant coating as a failure criterion does not fully reflect the flame retardant properties of the fire retardant coating, which is the most critical factor in determining its failure; and 3) The fire retardant coating uses a muffle furnace to expand under temperature rise, which does not conform to the actual scenario of a cable fire. The existing invention patent application, publication number CN112697953A, "A System and Method for Testing the Combustion and Pyrolysis Characteristics of Cables under Multi-Variable Parameter Environmental Conditions," includes a gas supply assembly, a test chamber, a monitoring assembly, and an analysis and control assembly. The gas cylinder assembly of the gas supply assembly feeds mixed gas into the test chamber via a gas mixing device. The test chamber is equipped with a radiation source at the top, a sample holder at the bottom, an observation assembly at the front, and a smoke hood at the right end. A baffle is located below the radiation source. The observation assembly is connected to the analysis and control assembly, which includes an infrared thermal imager and a high-definition camera. The monitoring assembly is connected to the analysis and control assembly, which includes an embedded thermocouple, a heat flow meter, a gas sensor, and a mass sensor. The analysis and control assembly includes a display panel, a control panel, a data acquisition unit, and a microprocessor. The existing solution focuses on testing the overall cable characteristics, and the existing technology is unable to test the cable and the coating in a humid and pressurized environment.

[0003] In summary, the existing technology has technical problems such as the test parameters are out of touch with reality, the flame retardant performance judgment criteria are set unreasonably, and the test scenario is single. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to solve the technical problems of test parameters being out of touch with reality, unreasonable setting of flame retardant performance criteria, and single test scenario.

[0005] The present invention solves the above technical problems by adopting the following technical solutions: A method for evaluating the operating status of a cable fire retardant coating comprises:

[0006] A test chamber is used to form a test space, wherein the test space includes: a test area and a control area; a cable test piece is placed at a preset test position in the test area, and is used to apply the fire retardant coating of the cable to be tested on its surface to prepare at least two groups of cable specimens, wherein the cable specimens include: an unaged group, an aged simulation group, and a group not coated with fire retardant coating;

[0007] A power supply system is installed in the control area. The power supply system includes three-phase and center lines, and three-phase and center line connecting cable test pieces, which are used to connect the aging simulation group using the power supply system to supply power to the aging simulation group.

[0008] The bracket is set up at the preset support position of the test area to support the cable specimen so that the cable specimen is suspended at the preset test position for aging simulation test;

[0009] The environmental simulation system includes a temperature control module, a humidity control module, and a spray pipe. The temperature control module and the humidity control module are installed in the control area. The humidity control module is connected to the spray pipe and is used to perform a heat and humidity resistance simulation operation in the test area according to preset differential environmental simulation parameters using the spray pipe. The spray pipe is controlled to spray the test liquid to the aging simulation group to obtain the heat and humidity resistance test results and the flushing aging test results.

[0010] The fault simulation system includes: a pressing rod, a support rod, a first force-bearing rod, a second force-bearing rod and a rotating bearing. The axial ends of the pressing rod, the first force-bearing rod and the second force-bearing rod are connected to the rotating bearing. The support rod includes: a supporting end and a force-applying end. The supporting end is connected to the rod arm of the pressing rod, and the transmission end is connected to the rod arm of the first force-bearing rod. The pressing end of the first force-bearing rod forms a protrusion, and the protruding position of the protrusion is arranged relative to the notch of the second force-bearing rod. In the test area, the protrusion and the notch are used to perform a steel wire pressing operation on the cable sample, so that in the control area, the power supply system is used to energize the cable sample to simulate a fault arc, so as to obtain cable fault data based on the test, and use the fault simulation system to test and obtain the carbonization length of the non-aging group, the aging simulation group and the group not coated with fire retardant paint, respectively. The carbonization length is processed using the preset cable operation status logic to obtain the evaluation result of the aging operation status of the cable fire retardant paint.

[0011] The present invention uses test parameters for simulated aging of cable fire retardant coatings that closely mirror the actual on-site environment of cable channels, simulating the actual application scenarios and emergencies of cable fire retardant coatings, so that the test results better reflect the actual operating status of the cable. The present invention uses the carbonization length of the unaged group, the aging simulation group, and the group without fire retardant coating as the test criteria, avoiding the drawback of traditional technologies that rely on the expansion ratio of fire retardant coatings as the failure criterion, resulting in relatively one-sided results on the flame retardant performance of fire retardant coatings.

[0012] In a more specific technical solution, the bracket includes: a bracket beam, at least two fixing clips, and at least two limiting rings.

[0013] The limiting ring is passed through the support beam to limit the cable sample to the preset test position;

[0014] The fixing clamp is installed on the bracket beam to clamp the cable sample and fix the cable sample at a preset test position.

[0015] In a more specific technical solution, the fault simulation system further includes: a base, on which the pressing rod, the first force-bearing rod, and the second force-bearing rod are supported.

[0016] In a more specific technical solution, the fault simulation system also includes: a lifting seat, which includes: a fault simulation operating table and a lifting movable frame. The base is installed on the fault simulation operating table, and the lifting movable frame is a telescopic part for adjusting the height of the fault simulation operation.

[0017] In a more specific technical solution, the second force-bearing rod further includes: a clamp and an arc-starting wire,

[0018] The clamps are installed on both sides of the slot;

[0019] The arc pilot wire is clamped in the clamp.

[0020] In a more specific technical solution, the test box further includes: a water collecting tank, which is arranged below the preset test position to collect the test liquid sprayed from the spray pipe.

[0021] In a more specific technical solution, the environmental simulation system also includes: a water outlet pipe, a water collection tank and a water intake pump.

[0022] A water outlet pipe, comprising a water inlet and a water outlet, wherein the water inlet is connected to the water collecting tank to discharge the experimental liquid in the water collecting tank;

[0023] a water collection tank connected to the water outlet to collect and store the experimental liquid;

[0024] The water intake pump comprises a water intake end and a water pumping end. The curved water end is connected to the water collection tank, and the water pumping end is connected to the spray pipe to serve as a liquid source for the spray pipe.

[0025] In a more specific technical solution, the power supply system includes: a three-phase power supply, an isolation transformer, a step-up transformer, a protective resistor, a voltmeter, an ammeter, and a fuse;

[0026] The three-phase power supply is connected to the step-up transformer via an isolation transformer;

[0027] The step-up transformer is connected to the first end of the cable test piece and the fuse, and the second end of the cable test piece is connected to the protective resistor and the ammeter;

[0028] The voltmeter is connected in parallel across the protective resistor.

[0029] The present invention uses a preset power supply system to energize the cable sample to perform fault simulation, avoiding the defect in traditional technology that the temperature rise of the muffle furnace causes the fireproof material to expand and does not conform to the real scene of cable fire.

[0030] In a more specific technical solution, the step-up transformer includes: an A-phase outgoing line, a B-phase outgoing line, a C-phase outgoing line, and a center line;

[0031] The center line is connected to the first end of the cable test piece;

[0032] The A-phase outgoing line, the B-phase outgoing line and the C-phase outgoing line are connected to fuses.

[0033] In a more specific technical solution, a method for evaluating the operating status of a cable fire retardant coating includes:

[0034] S1. Apply the fire retardant coating to the surface of the cable specimen to prepare at least two groups of cable specimens, wherein the cable specimens include: an unaged group, an aged simulation group, and a group not coated with fire retardant coating;

[0035] S2. Connect the aging simulation group using the power supply system to supply power to the aging simulation group;

[0036] S3. Use a bracket to support the cable specimen and hang it at a preset test position for aging simulation test;

[0037] S4. In the test area, according to the preset differential environmental simulation parameters, use the spray pipe of the environmental simulation system to perform a moisture and heat resistance simulation operation. Control the spray pipe to spray the test liquid to the aging simulation group to obtain the moisture and heat resistance test results and the erosion aging test results.

[0038] S5. In the test area, the cable specimens are pressed with steel wires using the protrusions and notches of the fault simulation system. In the control area, the cable specimens are energized by the power supply system to simulate a fault arc, thereby obtaining cable fault data. The fault simulation system is used to obtain the carbonization lengths of the non-aged group, the aged simulation group, and the group not coated with fire retardant coating. The carbonization lengths are processed using the preset cable operation status logic to obtain the evaluation results of the cable fire retardant coating aging operation status.

[0039] The present invention has the following advantages over existing technologies: It uses test parameters that simulate the aging of cable fire retardant coatings that closely mirror the actual on-site environment of cable channels, simulating the actual application scenarios and emergencies of cable fire retardant coatings, allowing the test results to better reflect the actual operating status of the cable. The present invention uses the carbonization length of the unaged group, the aging simulation group, and the group without fire retardant coating as the test criteria, avoiding the drawback of traditional technologies that rely on the expansion ratio of the fire retardant coating as the failure criterion, resulting in relatively one-sided results on the flame retardant performance of the fire retardant coating.

[0040] The present invention uses a preset power supply system to energize the cable sample to perform fault simulation, avoiding the defect in traditional technology that the temperature rise of the muffle furnace causes the fireproof material to expand and does not conform to the real scene of cable fire.

[0041] The present invention solves the technical problems in the prior art of test parameters being out of touch with reality, unreasonable setting of flame retardant performance criterion, and single test scenario. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the overall structure of a cable fire retardant coating operating status evaluation device according to Example 1 of the present invention;

[0043] Figure 2 This is a schematic diagram of the connection of specific components of the power supply system of Example 1 of the present invention;

[0044] Figure 3 This is a schematic diagram of the specific structure of the fault simulation system according to Example 1 of the present invention;

[0045] Figure 4 This is a schematic diagram of the basic steps of a method for evaluating the operating status of a cable fire retardant coating according to Example 1 of the present invention;

[0046] Figure 5 This is a schematic diagram of the specific steps of the fire retardant coating operation status test experiment in Example 1 of the present invention. DETAILED DESCRIPTION

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, 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 only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0048] Example 1

[0049] like Figure 1 As shown, the present invention provides a cable fire retardant coating operation status evaluation device, which includes a cable test piece 1, a test box 2, a bracket 3, a power supply system 4, a fault simulation system 5, and an environment simulation system 6.

[0050] In this embodiment, the evaluation objects of a cable fire retardant coating operation status evaluation device include but are not limited to: cable fire retardant coating and cable flame retardant tape.

[0051] In this embodiment, the test box 2 is used to provide a test space, and the test box 2 includes: a test area and a control area.

[0052] In this embodiment, the bracket 3 supports the cable test piece 1 to be suspended in the air. In this embodiment, the bracket 3 is provided with a fixing clamp 31 and a ring 32 to keep the cable test piece 1 fixed in the suspended position.

[0053] like Figure 2 As shown, in this embodiment, the power supply system 4 includes: a three-phase power supply 41, an isolation transformer 42, a step-up transformer 43, a protective resistor 44, a voltmeter 45, an ammeter 46, a fuse 47 and a buckle 48.

[0054] In this embodiment, a three-phase power supply 41 is connected to a step-up transformer 43 via an isolation transformer 42. The outputs of the step-up transformer, divided into phases A, B, and C, are connected to one end of the cable specimen 1. Phases A, B, and C are connected to fuses 47. The other end of the cable specimen 1 is connected in sequence to a protective resistor 44 and an ammeter 46. A voltmeter 45 is connected in parallel across the protective resistor 44.

[0055] like Figure 3 As shown, in this embodiment, the fault simulation system 5 includes a pressing rod 51, a support rod 52, a first force-bearing rod 53, a second force-bearing rod 54, an arc-starting wire 55, a base 56, a rotating bearing 57, a notch 58, a pressure-reducing spring 59, and a lifting seat 510.

[0056] In this embodiment, the environmental simulation system 6 includes a temperature control module 61 , a humidity control module 62 , a spray pipe 63 , a water collection tank 64 and a water pump 65 .

[0057] In this embodiment, the specifications of the cable specimen can be, for example: a 1000V cross-linked polyethylene insulated PVC sheath power cable with an outer diameter of the cable being (30±2) mm, a conductor cross-sectional area of 3×50 mm2 + 1×25 mm2, and a sheath oxygen index value of 25.0±0.5, which is used as the base material for the cable fire retardant coating to be tested.

[0058] In this embodiment, the dimensions of the test area can be, for example: 1.2 m high, 1.2 m wide, and 1.5 m long inside. Ventilation holes 211 are provided on the upper layer roof 21 every 0.5 m. In this embodiment, the specifications of the ventilation holes 211 can be, for example: a hole diameter of 1 cm. Slots 22 are provided on the roof 212 of the upper partition 21, and the test chamber 2 can be closed by using the slots 22 and the slot partition 23 to achieve smothering fire extinguishing. In this embodiment, a water collecting tank 24 is provided at the bottom of the test chamber 2 and is connected to an external water collecting pool 64 through a water outlet pipe 25. In this embodiment, the opening and closing method of the water outlet pipe

[0059] In this embodiment, the fault simulation system 5 includes:

[0060] A pressing rod 51, a first stress rod 53, a second stress rod 54, and a base 56 are connected in sequence from top to bottom. An opening is provided at the end of the base 56 to insert a rotating bearing 561;

[0061] In this embodiment, a support rod 52 is connected to the pressing rod 51 and the first stress rod 53. In this embodiment, the connection method with the pressing rod 51 and the first stress rod 53 can be, for example: rigid connection;

[0062] In this embodiment, a protrusion 531 is provided at the head end of the first stress rod 53, and the protrusion 531 corresponds to the position of a notch 541 on the second stress rod 54 downward;

[0063] In this embodiment, clamping members 5411 are installed on both sides of the notch 541 of the second stress rod 54 to clamp the lead arc 5412 from both sides. At the same time, the bottom surface of the front end of the second stress rod 54 is arc-shaped. In this embodiment, the radius of this arc can be, for example: 15 mm;

[0064] In this embodiment, the lead arc 5412 is a "C"-shaped iron wire. In this embodiment, the specifications of the lead arc 5412 can be, for example: 24 mm long and 10 mm long on both sides;

[0065] In this embodiment, the top surface of the front end of the base 56 is arranged opposite to the notch 541 of the second stress rod 54, and a groove is provided. In this embodiment, the processing specifications of the groove can be, for example: in the shape of an arc with a radius of 15 mm;

[0066] In this embodiment, the pressure reducing spring 59 is installed at the contact position between the base 56 and the end of the second force-bearing rod 54; the base 56 is installed on the lifting seat 510 to achieve vertical height adjustment.

[0067] In this embodiment, the temperature and humidity scenarios set in the environmental simulation system 6 include: a temperature of 47° C. and a relative humidity of 95%. A sodium chloride solution is sprayed onto the cable to be tested through the spray pipe 63. In this embodiment, the concentration of the sodium chloride solution can be set to, for example, 3%, and the flow rate can be set to, for example, 3 L / min.

[0068] In this embodiment, the water collection tank 64 contains the sodium chloride solution collected from the water collection tank 24 and the water outlet pipe 25; in this embodiment, the water intake pump 65 takes water from the water collection tank 64 and supplies it to the spray pipe 63 through the water pipe.

[0069] Example 2

[0070] like Figure 4 As shown, in this embodiment, a method for evaluating the operating status of a cable fire retardant coating includes the following basic steps:

[0071] Step S1, preparing two groups of cable samples using uncoated cable fire retardant coating, i.e., coating the cables with the coating, one group being an unaged group and the other being an aged simulation group;

[0072] Step S2: Connect the cable samples of the aging simulation group to the power system 4 according to the three phases A, B, and C and the center line. In this embodiment, the connection is sealed with a 1:1 mixture of paraffin wax and rosin, and then fixed to a bracket for an aging simulation test. In this embodiment, the sealing length can be, for example, 3-4 mm.

[0073] Step S3, conducting a fire retardant coating operation status test on the non-aging group cable samples, the aging simulation group cable samples, and the cable samples not coated with fire retardant coating respectively;

[0074] In this embodiment, when the evaluation object is fireproof tape, flame-retardant tape samples are collected from the unaged group cable samples and the aged simulation group cable samples, and oxygen index tests are performed on them respectively, and the oxygen index operating state of the cable flame-retardant tape is obtained as a1=O1 / O2.

[0075] Step S4: Remove the coating and press the cable substrate surface with a sharp object. If the surface changes from elastic to brittle or powdery, it indicates that the cable substrate has begun to carbonize. Then, use a steel tape measure to measure the maximum distance from the fault point to the carbonized portion of the cable substrate. This is the carbonized length of the test piece.

[0076] Step S5: The carbonized lengths of the unaged cable sample, the aged simulation cable sample, and the uncoated fire retardant coating cable sample are respectively counted as L1, L2, and L0. The post-aging operating state a of the cable fire retardant coating is calculated as a=(L2-L0) / (L1-L0).

[0077] In this embodiment, when the evaluation object is a fireproof tape, the carbonized lengths of the unaged group cable samples, the aged simulation group cable samples, and the unwrapped cable flame-retardant tape cable samples are respectively counted as L1, L2, and L0, and the carbonized length operating state a2 of the cable flame-retardant tape is calculated as a2=(L2-L0) / (L1-L0); the cable flame-retardant tape operating state a is calculated, where a=(a1+a2) / 2.

[0078] In this embodiment, step S2 includes: using the environmental simulation system 6, conducting a 7-day moisture and heat resistance aging simulation test on the cable samples of the aging simulation group, and then conducting a 7-day sodium chloride salt water flushing aging simulation test.

[0079] like Figure 5 As shown, in this embodiment, step S3 includes:

[0080] S31. Adjust the environmental simulation system so that the sample is placed at (20±10)℃ for at least 16 hours and ensure that the sample is dry;

[0081] S32. Disconnect the power supply, remove the end cap of the sample mixture, and keep the sample surface clean;

[0082] S33, using the fault simulation system 5, pressing a steel wire into the center of the cable sample to form a short circuit loop;

[0083] S34. Connect the power supply and allow the cable sample to form an arc at the simulated fault location;

[0084] S35, the air flow introduced through the ventilation holes 211 above the test box 2 maintains the cable burning, and waits for the burning to complete. In this embodiment, the cable burning time interval includes: 0 to 1 hour, after which the test box 2 is sealed by the slot partition 23 to achieve asphyxiation and extinguish the fire.

[0085] In summary, the present invention uses test parameters for simulating the aging of cable fire retardant coatings that are close to the actual on-site environment of cable channels, simulating the actual application scenarios and emergencies of cable fire retardant coatings, so that the test results better reflect the actual operating status of the cable. The present invention uses the carbonization length of the unaged group, the aging simulation group, and the group not coated with fire retardant coating as the test criteria, avoiding the defect of traditional technology that relies on the expansion ratio of fire retardant coating as the failure criterion, resulting in a relatively one-sided result of the flame retardant performance of the fire retardant coating.

[0086] The present invention uses a preset power supply system to energize the cable sample to perform fault simulation, avoiding the defect in traditional technology that the temperature rise of the muffle furnace causes the fireproof material to expand and does not conform to the real scene of cable fire.

[0087] The present invention solves the technical problems in the prior art of test parameters being out of touch with reality, unreasonable setting of flame retardant performance criterion, and single test scenario.

[0088] 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 they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. 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 various embodiments of the present invention.

Claims

1. A cable fire retardant coating operating status evaluation device, characterized in that: The device comprises: A test chamber is used to form a test space, wherein the test space includes: a test area and a control area; a cable test piece is placed at a preset test position in the test area, and is used to apply the fire retardant coating of the cable to be tested on its surface to prepare at least two groups of cable specimens, wherein the cable specimens include: an unaged group, an aged simulation group, and a group not coated with fire retardant coating; A power supply system is installed in the control area. The power supply system includes three-phase and center lines, and three-phase and center line connecting cable test pieces, which are used to connect the aging simulation group using the power supply system to supply power to the aging simulation group. The power supply system includes: three-phase power supply, isolation transformer, step-up transformer, protection resistor, voltmeter, ammeter, and fuse; The three-phase power supply is connected to the step-up transformer via an isolation transformer; The step-up transformer is connected to the first end of the cable test piece and the fuse, and the second end of the cable test piece is connected to the protective resistor and the ammeter; The voltmeter is connected in parallel across the protective resistor; The step-up transformer includes: A-phase outgoing line, B-phase outgoing line, C-phase outgoing line and center line; The center line is connected to the first end of the cable test piece; A phase outgoing line, B phase outgoing line and C phase outgoing line are connected to fuses; The bracket is set up at the preset support position of the test area to support the cable specimen so that the cable specimen is suspended at the preset test position for aging simulation test; The environmental simulation system includes a temperature control module, a humidity control module, and a spray pipe. The temperature control module and the humidity control module are installed in the control area. The humidity control module is connected to the spray pipe. In the test area, according to the preset differential environmental simulation parameters, the spray pipe is used to perform a moisture and heat resistance simulation operation. The spray pipe is controlled to spray the test liquid to the aging simulation group to obtain the moisture and heat resistance test results and the flushing aging test results. The fault simulation system includes: a pressing rod, a support rod, a first force-bearing rod, a second force-bearing rod and a rotating bearing. The axial ends of the pressing rod, the first force-bearing rod and the second force-bearing rod are connected to the rotating bearing. The support rod includes: a supporting end and a force-applying end. The supporting end is connected to the rod arm of the pressing rod, and the force-applying end is connected to the rod arm of the first force-bearing rod. The pressing end of the first force-bearing rod forms a protrusion, and the protruding position of the protrusion is arranged relative to the notch of the second force-bearing rod. In the test area, the protrusion and the notch are used to perform a steel wire pressing operation on the cable sample, so that in the control area, the power supply system is used to energize the cable sample to simulate a fault arc, and the cable fault data is obtained based on the test. The fault simulation system is used to test and obtain the carbonization length of the non-aging group, the aging simulation group and the group not coated with fire retardant paint respectively. The carbonization length is processed using the preset cable operation status logic to obtain the cable fire retardant paint aging operation status evaluation result. The carbonization length is the maximum length from the cable fault point to the carbonization point of the cable substrate.

2. A cable fire retardant coating operating status evaluation device according to claim 1, characterized in that: The bracket includes: a bracket crossbeam, no less than 2 fixing clips, and no less than 2 limiting rings. The limiting ring is provided through the support crossbeam to limit the cable sample to the preset test position; The fixing clamp is installed on the support beam to clamp the cable sample and fix the cable sample at the preset test position.

3. A cable fire retardant coating operating status evaluation device according to claim 1, characterized in that: The fault simulation system further includes a base, on which the pressing rod, the first force-bearing rod, and the second force-bearing rod are supported.

4. A cable fire retardant coating operating status evaluation device according to claim 1, characterized in that: The fault simulation system further comprises a lifting seat, which comprises a fault simulation operating table and a lifting movable frame. The base is mounted on the fault simulation operating table, and the lifting movable frame is a telescopic member for adjusting the height of the fault simulation operation.

5. The cable fire retardant coating operating status evaluation device according to claim 1, characterized in that: The second stress-bearing rod further includes: a clamp and an arc-starting wire, The clamps are installed at both sides of the notch; The arc-starting wire is clamped by the clamp.

6. A cable fire retardant coating operating status evaluation device according to claim 1, characterized in that: The test box further includes a water collecting tank, which is arranged below the preset test position to collect the test liquid sprayed from the spray pipe.

7. The cable fire retardant coating operating status evaluation device according to claim 1, characterized in that: The environmental simulation system also includes: a water outlet pipe, a water collection tank and a water pump. The water outlet pipe includes a water inlet and a water outlet, wherein the water inlet is connected to a water collecting tank to discharge the experimental liquid in the water collecting tank; a water collection tank connected to the water outlet to collect and store the experimental liquid; The water intake pump comprises a water intake end and a water pumping end. The water intake end is connected to the water collection tank, and the water pumping end is connected to the spray pipe to serve as a liquid source for the spray pipe.

8. A method for evaluating the operating status of a cable fire retardant coating, applied to a device for evaluating the operating status of a cable fire retardant coating according to any one of claims 1 to 7, characterized in that: The method comprises: S1. Apply fire retardant coating to the surface of the cable specimen to be tested to prepare at least two groups of cable specimens, wherein the cable specimens include: an unaged group, an aged simulation group, and a group not coated with fire retardant coating; S2. Connecting the aging simulation group using a power supply system to supply power to the aging simulation group; S3. Support the cable sample with a bracket so that the cable sample is hung at a preset test position for aging simulation test; S4. In the test area, according to preset differential environmental simulation parameters, use the spray pipe of the environmental simulation system to perform a moisture and heat resistance simulation operation, control the spray pipe to spray the test liquid to the aging simulation group, and obtain moisture and heat resistance test results and erosion aging test results; S5. In the test area, the cable sample is pressed into a steel wire using the protrusions and notches of the fault simulation system, so that in the control area, the cable sample is energized by the power supply system to simulate a fault arc, thereby obtaining cable fault data through the test, and the carbonization lengths L1, L2, and L0 of the non-aged group, the aged simulation group, and the group not coated with fire retardant coating are obtained through the fault simulation system. The carbonization lengths are processed using a preset cable operation state logic to obtain an evaluation result of the aging operation state of the cable fire retardant coating, where the aging state a=(L2-L0) / (L1-L0). The carbonization length is the maximum length from the cable fault point to the carbonization point of the cable substrate.

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