Electric arc protection clothes thermal protection performance test method, device, medium and system

Abstract

The invention belongs to the technical field of electric power labor protection articles, and particularly relates to a thermal protection performance testing method for arc protection clothes, which comprises the following steps: simulating arcs of different types and strengths in a laboratory through a double-LC oscillating circuit, and placing an arc protection clothes manufacturing material on a copper calorimeter at the periphery of the arcs to test the thermal protection performance of the arc protection clothes. The surface temperature change of the copper calorimeter is recorded, the heat penetrating through the material is calculated in real time, the heat is converted into the temperature change on a Stokes curve, whether the heat burns the skin of an operator or not is judged according to the temperature change, and the testing method is low in cost, short in experimental period, easy to regulate and control and suitable for popularization and application. Experimental measurement can be quickly and conveniently carried out on the anti-electricity fabric. Based on the same inventive concept, the invention further provides a device for testing the thermal protection performance of the arc protection clothes, a non-transient readable recording medium storing a program of the method and a system comprising the medium, and the program can be called through a processing circuit to execute the method.

Description

Technical Field

[0001] The invention belongs to the technical field of electric labor protection products, and discloses a method, a device, a system for testing the thermal protection performance of arc protection clothing, and a recording medium storing a program capable of executing the method. Background Art

[0002] The distribution network connects the power system with the users and is the last step in delivering electricity to the users. Live working can inspect and repair overhead lines, distribution cabinets and other equipment without stopping the power grid, which is of great significance to the improvement of power supply reliability and quality. Usually, distribution lines and distribution stations are connected to many high-voltage lines and substations, and large electrical equipment is also installed on the same line. A distribution line is usually directly connected to multiple high-voltage users and substations, and many electrical equipment are directly installed on the distribution line. This poses a huge threat to the personal safety of workers working on live lines.

[0003] Arc accidents during live work can instantly release high energy, causing casualties among power workers. Arc protection clothing has flame retardant, heat resistant, non-melting and excellent electrical insulation properties. When encountering an arc or flame, it will expand and thicken to form a protective wall, isolating the body from the heat source, ensuring that workers have sufficient time to evacuate the arc accident site. Reasonable configuration of arc protection equipment can effectively reduce the harm of arc accidents to workers.

[0004] Arc-proof clothing must be thick enough to protect the operator's skin from burns by the radiant heat of the arc, but also light and breathable to facilitate climbing operations. For arcs of different types and intensities, how to evaluate the performance of materials to be used to manufacture arc-proof clothing has become an urgent problem for arc-proof clothing designers to solve. Summary of the invention

[0005] In view of the above problems, the present invention provides a device for testing the thermal protection performance of arc protection clothing, comprising:

[0006] Arc generation circuit, arc energy measurement system; wherein the arc generation circuit includes a short-circuit current circuit and a charging voltage circuit, a simulated short-circuit branch and an arc generation branch connected in parallel and composed of an LC oscillation circuit; the capacitor in the charging voltage circuit is a pulse capacitor composed of a series and parallel combination, an ignition ball gap for inducing high voltage is connected in series between the positive electrode of the pulse capacitor and the inductor, and a resistor-capacitor voltage divider branch for measuring transient recovery voltage is connected in parallel between the negative electrode and the inductor; the pulse capacitor is connected in parallel with a resistor voltage divider branch for measuring the capacitor charging voltage; the capacitor in the short-circuit current circuit is composed of a capacitor stack connected in parallel, which is connected in parallel with a power supply branch with a circuit breaker as a whole, and a Rogowski coil for measuring the breaking current is provided in the short-circuit current circuit; the simulated short-circuit branch is a conductor provided with a circuit breaker, and the arc generation branch includes a circuit breaker and positive and negative electrodes connected in series, and a copper wire for fusing to form an arc is connected between the positive and negative electrodes; the capacitance value or the inductance value in the LC oscillation circuit can be adjusted;

[0007] The arc energy measurement system includes a copper calorimeter whose heated surface faces the normal direction of the arc, and a thermocouple for real-time temperature signal collection is connected to the heated surface.

[0008] Preferably, the distance between the positive and negative electrodes is adjustable, and the distance between the copper calorimeter and the positive and negative electrodes is adjustable.

[0009] Preferably, the positive and negative electrodes are both rod-shaped, with a nominal diameter of 19 mm and a length of 450 mm, which can be telescopically adjusted. The copper wire has a diameter of 0.25 mm, and both ends are fixed to the positive and negative electrodes respectively by nylon tie bands.

[0010] Based on the same inventive concept, the present application also provides a method for testing the thermal protection performance of arc protection clothing, including: using the above-mentioned arc protection clothing thermal protection performance testing device, including the following steps:

[0011] S1. Build an arc generating circuit, which is used to charge the capacitor through a power supply, and then form an LC oscillation circuit with the capacitor and the inductor to generate an overload current, causing the copper wire between the electrodes to fuse and start the arc; by adjusting the parameter values ​​of the capacitor and the inductor, the frequency of the arc generating circuit can be adjusted, and by changing the charging voltage value, the current size of the arc generating circuit can be adjusted to simulate the arc generated under different working conditions;

[0012] S2. Build an arc energy measurement system to calculate the energy of arc radiation absorbed by the copper calorimeter in real time by measuring the temperature change of the copper calorimeter around the arc;

[0013] S3. Adjust the relevant parameters of the arc generating circuit to meet the energy threshold value of the energy that causes a burn accident under specific working conditions;

[0014] S4. Covering the heating surface of the copper calorimeter with a single layer of material for making arc protection clothing, measuring the temperature change of the copper calorimeter around the arc and converting it into a temperature change curve of human skin tissue under the same heat absorption in real time;

[0015] S5. Analyze the temperature change curve of human skin tissue to see if it causes burns to the human body in order to evaluate the thermal protection performance of arc protection clothing.

[0016] Preferably, the relevant parameters in the step of adjusting the relevant parameters of the arc generating circuit include but are not limited to one or more of the following parameters:

[0017] The capacitance or inductance value in the LC oscillation circuit; the distance between the positive and negative electrodes, and the voltage and capacity that the power branch can provide.

[0018] Another embodiment of the present invention is to provide a non-transitory readable recording medium for storing one or more programs including a plurality of instructions. When the instructions are executed, the processing circuit will execute the above-mentioned arc protection clothing thermal protection performance testing method.

[0019] The present invention also provides a thermal protection performance testing system for arc protection clothing, including a processing circuit and a memory electrically coupled thereto, characterized in that the memory is configured to store at least one program, the program includes multiple instructions, and the processing circuit runs the program to execute the above-mentioned thermal protection performance testing method for arc protection clothing.

[0020] Compared with the prior art, the thermal protection performance test device, method and system of arc protection clothing provided by the present invention can better simulate various arc working conditions in the laboratory, test the thermal protection performance of arc protection fabric materials, and provide experimental basis for the design and development of arc protection clothing. The test platform has low manufacturing cost, short experimental cycle, easy control, and can quickly and conveniently perform experimental measurements on arc protection fabrics. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the electrical structure of the arc generating circuit in an embodiment of the present invention;

[0022] Figure 2 It is a partially enlarged schematic diagram of the arc energy measurement system in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described below in conjunction with the drawings in the embodiments of the present invention. The described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making innovative efforts are within the scope of protection of the present invention.

[0024] The following technical solutions and attached Figure 1-2 , specifically illustrating the implementation process of the present invention, including building an arc protection clothing thermal protection performance test platform (device embodiment) and using the platform to test the arc protection clothing thermal protection performance (method embodiment).

[0025] Step 1: Build an arc generation platform based on a synthetic circuit

[0026] According to the provisions of ASTMF1959 and IEC61482, combined with laboratory equipment, a synthetic loop high current system is used to build a test platform. The capacitor bank is charged by a power supply, and then the capacitor and inductor form an LC oscillation circuit to generate a large current. A fuse is used between the electrodes to start the arc. By adjusting the parameter values ​​of the capacitor and inductor, the frequency of the test loop can be adjusted, and by changing the charging voltage value, the size of the loop current can be adjusted.

[0027] A low-voltage, high-current source is used to form a short-circuit current loop, and a high-voltage, low-current source is used to form a voltage loop. During the platform construction test, a low-voltage, high-current source is used to ignite the arc. Before or after the arc current crosses the zero point, a high-voltage power source is added to connect the current source and the voltage source. They are used as a power source to generate a transient recovery voltage. The synthetic circuit test device is divided into a voltage loop and a current loop. Both the voltage source and the current source use an LC oscillation circuit.

[0028] High voltage circuits such as Figure 1 As shown on the left, C1 and L1 are the capacitance and inductance of the voltage source. When C1 and L1 oscillate, a power frequency recovery voltage will be generated. In this case, the capacitance and inductance parameters of C1 and L1 must be reasonably configured. The capacitors are pulse capacitors. These capacitors can be adjusted to meet the capacitance and charging voltage required for the test through appropriate series and parallel combinations. The inductor coil can be adjusted to multiple sets of inductance values ​​that meet the test requirements through appropriate adjustment combinations.

[0029] High current loops such as Figure 1As shown on the right, C2 is the capacitor of the current source, L2 is the inductor of the current source, and the power frequency test current is generated by LC oscillation. C2 is a feature of the synthetic test circuit, which is composed of capacitor stacks in parallel. Each group of capacitor stacks is composed of capacitors connected in series and parallel with several resistors, diodes, and relays. The current source of this method has the characteristics of small size and large capacity. L2 is located below C2. Each inductor winding has an inductor coil. The charged C2 discharges the inductor L2. If the parameters are matched properly, a short-circuit current of about 50Hz can be obtained. By closing switch AB, the rectified power frequency voltage is used to charge capacitor C2. When the capacitor is fully charged, AB is disconnected and the charging process is completed. CB is a closing circuit breaker, which is used to control the discharge of C2 and introduce a simulated power grid short-circuit fault current into the circuit. TB is a closing circuit breaker that can introduce a simulated power grid short-circuit fault current into the circuit.

[0030] RVDT is a resistor voltage divider that can measure the charging voltage of C1 when it is charging. RCVDT is a resistor-capacitor voltage divider that can measure the transient recovery voltage during the test. SG is the ignition ball gap, which is used to ignite the high voltage. CB is the closing circuit breaker, and AB is the auxiliary circuit breaker. The opening and closing of the CB and AB circuit breakers are used to control the opening and closing process of the circuit. Rogowski coil, referred to as Rog, is used together with the integrator Int to measure the breaking current. This signal is also derived from the interface of Int, and then connected to the console in the control room, and can be connected to the channel of the oscilloscope. The common ground of the voltage loop and the current loop is GND.

[0031] Step 2: Build the arc energy measurement system;

[0032] The schematic diagram of the arc energy test system is as follows: Figure 2 As shown. The base of the electrode frame structure is supported by insulators to ensure insulation between the electrode frame structure and the ground. The supporting part of the electrode frame is connected by insulating rods, and thick steel plates are used as bases at both ends. The insulating rods and thick steel plates are connected by gaskets, threads and bolts to ensure that the electrode frame structure has good structural strength. The electrode device uses copper material with good conductivity as the electrode rod. The nominal diameter of the electrode rod is 19mm and the length is 450mm. The electrode rod can be adjusted up and down to meet the needs of different distances between electrodes.

[0033] Arc accidents are sudden, hidden and random. Arc accidents are accompanied by strong light and high temperatures. The temperature of the arc may reach 4000-50000K in a short time. The arc spray direction is random, and the arc energy sprayed in all directions is also uncertain. When the arc spray direction is facing the copper calorimeter, the arc energy measured by the copper calorimeter is the most accurate. As an important part of the arc energy measurement system, the copper calorimeter receives more than 90% of the energy radiated by the arc. The thermocouple connected to the copper sheet can sense the temperature change of the copper sheet to generate a thermoelectric potential signal, and then the thermoelectric potential signal is converted into a temperature signal through the temperature data acquisition system. The heat capacity parameter of the copper sheet material is used to calculate the energy of the arc radiation absorbed by the copper calorimeter. This energy value is approximately the energy of the arc accident.

[0034] Step 3: Determine whether the arc in the simulated accident on the platform has enough energy to penetrate general protective clothing materials and cause burns;

[0035] According to the provisions of the standard DL / T 320-2019 "General Technical Requirements for Personal Arc Protection Equipment", the two core indicators of arc protective clothing are the arc thermal protection performance value and the material rupture threshold. The arc thermal protection performance value refers to the energy value at which there is a 50% probability that the heat will penetrate the material and cause a second-degree burn when the energy received by the protective material. When the external energy is lower than this value, the material can effectively block and reduce the conduction of energy, thereby preventing human skin from suffering second-degree or higher burns. The rupture threshold refers to the energy value at which there is a 50% probability of causing a single-layer or multi-layer arc protection material to rupture.

[0036] Under the condition of 12.3kA current, the maximum arc heat flux was calculated to be 110.72J / cm 2 This value is higher than the 104.60J / cm2 required for level II protection in the national standard. 2 Threshold, indicating that the platform meets the requirements of level II protection test. Under the condition of 12.3kA current, the thermal protection performance of the fabric (i.e. arc protection clothing manufacturing) was tested.

[0037] Step 4: Thermal protection performance test of arc protective clothing

[0038] The arc energy is measured under the condition of a current level of 4kA. The test conditions are that the electrode spacing between the two copper electrode rods is 35mm, and the distance between the copper calorimeter and the electrode rod is 25mm, that is, the measurement distance is 25mm. Adjust the charging voltage of the capacitor bank, and the current level in the circuit can be observed through the oscilloscope. In order to ensure the accuracy and rationality of the arc energy measurement during the test, it is necessary to measure 20 sets of test data under the same test conditions, and take the test data with the largest temperature rise of the copper calorimeter as the measured value of the arc energy. After each test, ensure that the temperature of the copper sheet of the copper calorimeter is cooled to the ambient temperature.

[0039] Based on the arc energy measurement value, a temperature change curve of human skin tissue when absorbing the same amount of heat (i.e., the Stoll curve) is drawn to determine whether the second-degree burn standard is reached.

[0040] In the experimental setup, the spacing between the copper electrodes was 15 mm, and the distance between the copper calorimeter and the electrodes was 25 mm. After covering the surface of the calorimeter with aramid fabric, the current in the circuit was measured using an oscilloscope by adjusting the charging voltage of the capacitor bank to ensure that the current was 12.3 kA. Twenty sets of experiments were conducted under the same conditions, and the highest temperature rise measured by the copper calorimeter in each experiment was recorded as the basis for calculating the arc heat flux. After each experiment, the temperature of the copper sheet was allowed to drop to ambient temperature, the temperature rise data was recorded, the temperature rise curve was drawn, and finally converted into a standard Stoll curve through energy calculation. The Stoll curve was used to determine whether the second-degree burn standard was reached, and the fabric was checked for obvious damage.

[0041] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computers, available storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.

[0042] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0043] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0044] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0045] Compiling the above method steps into a program and then storing it on a hard disk or other non-transitory storage medium constitutes an embodiment of "a non-transitory readable recording medium" of the present invention; and electrically connecting the storage medium to a computer processor and completing the thermal protection performance test of the arc protection clothing through data processing constitutes an embodiment of "a thermal protection performance test system for arc protection clothing" of the present invention.

[0046] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for testing the thermal protection performance of arc protection clothing, characterized in that include: Arc generation circuit, arc energy measurement system; wherein the arc generation circuit includes a short-circuit current circuit and a charging voltage circuit, a simulated short-circuit branch and an arc generation branch connected in parallel and composed of an LC oscillation circuit; the capacitor in the charging voltage circuit is a pulse capacitor composed of a series and parallel combination, an ignition ball gap for inducing high voltage is connected in series between the positive electrode of the pulse capacitor and the inductor, and a resistor-capacitor voltage divider branch for measuring transient recovery voltage is connected in parallel between the negative electrode and the inductor; the pulse capacitor is connected in parallel with a resistor voltage divider branch for measuring the capacitor charging voltage; the capacitor in the short-circuit current circuit is composed of a capacitor stack connected in parallel, which is connected in parallel with a power supply branch with a circuit breaker as a whole, and a Rogowski coil for measuring the breaking current is provided in the short-circuit current circuit; the simulated short-circuit branch is a conductor provided with a circuit breaker, and the arc generation branch includes a circuit breaker and positive and negative electrodes connected in series, and a copper wire for fusing to form an arc is connected between the positive and negative electrodes; the capacitance value or the inductance value in the LC oscillation circuit can be adjusted; The arc energy measurement system includes a copper calorimeter whose heated surface faces the normal direction of the arc, and a thermocouple for real-time temperature signal collection is connected to the heated surface.

2. The arc protection clothing thermal protection performance testing device according to claim 1 is characterized in that: The distance between the positive and negative electrodes is adjustable, and the distance between the copper calorimeter and the positive and negative electrodes is adjustable.

3. The arc protection clothing thermal protection performance testing device according to claim 1 is characterized in that: Both the positive and negative electrodes are rod-shaped, with a nominal diameter of 19 mm and a length of 450 mm, which can be telescopically adjusted. The diameter of the copper wire is 0.25 mm, and the two ends are fixed to the positive and negative electrodes respectively by nylon ties.

4. A method for testing the thermal protection performance of arc protection clothing, using the device for testing the thermal protection performance of arc protection clothing according to claim 1, characterized in that The following steps are involved: S1. Build an arc generating circuit, which is used to charge the capacitor through a power supply, and then form an LC oscillation circuit with the capacitor and the inductor to generate an overload current, causing the copper wire between the electrodes to fuse and start the arc; by adjusting the parameter values ​​of the capacitor and the inductor, the frequency of the arc generating circuit can be adjusted, and by changing the charging voltage value, the current size of the arc generating circuit can be adjusted to simulate the arc generated under different working conditions; S2. Build an arc energy measurement system to calculate the energy of arc radiation absorbed by the copper calorimeter in real time by measuring the temperature change of the copper calorimeter around the arc; S3. Adjust the relevant parameters of the arc generating circuit to meet the energy threshold value of the energy that causes a burn accident under specific working conditions; S4. Covering the heating surface of the copper calorimeter with a single layer of material for making arc protection clothing, measuring the temperature change of the copper calorimeter around the arc and converting it into a temperature change curve of human skin tissue under the same heat absorption in real time; S5. Analyze the temperature change curve of human skin tissue to see if it causes burns to the human body in order to evaluate the thermal protection performance of arc protection clothing.

5. A method for testing the thermal protection performance of arc protection clothing according to claim 4, characterized in that: The relevant parameters in the step of adjusting the relevant parameters of the arc generation circuit include but are not limited to one or more of the following parameters: The capacitance or inductance value in the LC oscillation circuit; the distance between the positive and negative electrodes, and the voltage and capacity that the power branch can provide.

6. A non-transitory readable recording medium for storing one or more programs including a plurality of instructions, characterized in that: When the instruction is executed, the processing circuit will be caused to execute a method for testing the thermal protection performance of arc protection clothing as described in any one of claims 4-5.

7. A thermal protection performance test system for arc protection clothing, characterized in that It comprises a processing circuit and a memory electrically coupled thereto, wherein the memory is configured to store at least one program, the program comprises a plurality of instructions, and the processing circuit runs the program to execute a method for testing the thermal protection performance of arc protection clothing as described in any one of claims 4-5.

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