Quantitative experiment method and system for cracking gas production characteristic of transformer insulating oil at constant temperature

Abstract

The invention relates to the technical field of cracking of transformer insulating oil, and provides a quantitative experiment method and system for cracking gas production characteristics of transformer insulating oil at a constant temperature in order to solve the problem that the gas quantity, component distribution and gas production rate generated by cracking of quantitative insulating oil at different temperatures cannot be accurately measured in the prior art. The quantitative experiment system for the cracking gas production characteristic of the transformer insulating oil at the constant temperature comprises a tubular furnace, a gas chromatograph and a processor, the tubular furnace is used for carrying out a constant-temperature cracking experiment on the insulating oil so as to collect cracking gas and record a pressure-time curve; calculating the total gas quantity and the total gas production rate in the tubular furnace by utilizing a processor according to an ideal gas equation and the change condition of pressure along with time, and obtaining the gas production quantity and the gas production rate of each gas component according to the proportion of each component; the gas quantity, the component distribution and the gas production rate generated by cracking of quantitative insulating oil at different temperatures can be accurately measured.

Description

Technical Field

[0001] This invention relates to the field of transformer insulating oil pyrolysis technology, and in particular to a quantitative experimental method and system for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] In existing technologies, studies on the isothermal pyrolysis gas generation process of insulating oil typically involve heating the insulating oil with a resistance wire and analyzing the pyrolysis gas. However, resistance wire heating leads to uneven temperature distribution within the oil, with significantly higher temperatures near the resistance wire. Furthermore, resistance wire heating makes precise temperature control difficult, often relying on voltage regulators to simply control the temperature. In addition, high-temperature pyrolysis experiments on insulating oil require a considerable amount of time to reach the designated temperature; pyrolysis can occur before the specified temperature is reached, leading to inaccurate experimental results.

[0004] In summary, the method of heating insulating oil with resistance wire and analyzing the pyrolysis gas has low temperature control accuracy, uneven temperature distribution, slow heating rate, and cannot accurately measure the amount, composition distribution, and gas generation rate of gas produced by the pyrolysis of insulating oil at different temperatures. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a quantitative experimental method and system for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature. It uses the ideal gas law to inversely deduce the changes in the amount of gas inside the furnace tube and analyzes the gas-generating components at different temperatures using a gas chromatograph. This enables precise measurement of the gas generation characteristics of insulating oil pyrolysis at different temperatures, and precise quantitative measurement of the amount of gas, component distribution, and gas generation rate generated by the pyrolysis of insulating oil at different temperatures.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides a quantitative experimental system for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature.

[0007] In one or more embodiments, a quantitative experimental system for the gas generation characteristics of transformer insulating oil pyrolysis under isothermal conditions is provided, comprising a tubular furnace, a gas chromatograph, and a processor; the tubular furnace includes a furnace tube, a material boat, a heat insulation block, a pusher rod, and a vacuum pump; heating elements are uniformly arranged around the middle periphery of the furnace tube to form a heating isothermal zone; both ends of the furnace tube are equipped with sealing flanges, one sealing flange is equipped with a pressure sensor and a gas outlet, and the other sealing flange is equipped with a gas inlet; the material boat contains a quantitative amount of insulating oil and is located inside the furnace tube on the left side; the heat insulation block is located inside the furnace tube and on the right side of the material boat, and the area to the right of the heat insulation block is the heating isothermal zone; the pusher rod is movably connected to the furnace tube to push the material boat and the heat insulation block into the heating isothermal zone; the vacuum pump is connected to the furnace tube; The gas chromatograph is connected to the gas outlet and is used to analyze the components and proportions of the pyrolysis gas inside the furnace tube. The gas chromatograph and the pressure sensor are both connected to the processor. The processor is used to generate a pressure-time curve based on the pressure of the pyrolysis gas inside the furnace tube detected by the pressure sensor, and to calculate the total gas volume and total gas production rate-time curve inside the tubular furnace using the ideal gas equation. Then, based on the component proportions of the pyrolysis gas, the gas production volume and gas production rate of each gas component are obtained.

[0008] As one implementation, water-cooling pipes are provided on both sides of the furnace tube to ensure that the temperature at both ends is lower than the phase change temperature of the insulating oil.

[0009] In one embodiment, the tubular furnace further includes a housing, and the furnace tubes are detachably connected within the housing.

[0010] A second aspect of the present invention provides a quantitative experimental method for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature.

[0011] In one or more embodiments, a quantitative experimental method for the gas generation characteristics of transformer insulating oil pyrolysis under isothermal conditions includes: Install a tubular furnace, evacuate the furnace using a vacuum pump, and then inject inert gas to the standard atmospheric pressure. Set the target temperature and continuously introduce inert gas during the heating process. Once the temperature in the constant temperature zone of the tubular furnace reaches the target temperature, close the gas passage and use a pusher rod to push the material boat and insulation block into the heating constant temperature zone to carry out the pyrolysis reaction. After the pressure inside the furnace tube stabilizes, collect the pyrolysis gas and record the pressure-time curve. The collected pyrolysis gas was analyzed using a gas chromatograph to obtain the components and their proportions. The processor calculates the total gas volume and total gas production rate inside the tubular furnace based on the ideal gas equation and the pressure-time curve. The calculated total gas volume and total gas production rate are then multiplied by the proportion of each component to obtain the gas production volume and gas production rate of each gas component.

[0012] As one implementation method, the pressure-time curve inside the furnace tube is denoted as... P ( t The initial amount of gaseous substance inside the furnace tube is denoted as . n 0, according to the ideal gas law P ( t ) V 0 =n ( t ) RT 0, temperature T 0 represents the set value and volume. V 0 represents the volume of the furnace tube. ，R Assuming the ideal gas constant, the pressure... P ( t Substitute the values ​​into the equation to solve for the amount of gaseous substance inside the furnace tube. n ( t ) = P ( t ) V / RT Then, the amount of gas produced can be determined. n 1( t )= n ( t )- n 0, finally obtaining the volume of the generated gas. V ( t ); t For time.

[0013] As one implementation method, the amount of gas generated is obtained. n 1( t ) and gas volume V ( t After that, the corresponding gas production rate is obtained by differentiating with respect to time. v (t)= dV ( t ) / dt .

[0014] As one implementation method, the process of analyzing the collected pyrolysis gas using a gas chromatograph is as follows: The collected pyrolysis gases were subjected to chromatographic analysis. Each sample was tested at least three times, and the final result was the average value. The content of different gas components was obtained through chromatographic analysis.

[0015] As one implementation method, the target temperature is lower than the limit temperature of the tubular furnace.

[0016] As one implementation method, when the temperature of the heating constant temperature zone of the tubular furnace reaches the target temperature value, the air inlet and outlet are closed.

[0017] As one implementation method, at the start of the experiment, insulating oil is injected into the material boat, the heat insulation block is placed from the left side of the furnace tube to the left side of the furnace tube, and then the material boat is placed to the left of the heat insulation block to ensure that the material boat is in the low temperature zone of the furnace tube.

[0018] Compared with the prior art, the beneficial effects of the present invention are: This invention enables high-temperature experiments to be conducted in a tubular furnace, allowing for the instantaneous and uniform achievement of a set temperature for quantitative experiments. By collecting pressure waveforms and pyrolysis gases during the high-temperature reaction process and recording pressure-time curves, the gas components and their proportions are determined using a gas chromatograph. Finally, based on the recorded pressure-time curves, the total gas volume and total gas production rate inside the tubular furnace are calculated according to the ideal gas equation through pressure changes within the furnace. The calculated total gas volume and total gas production rate are then multiplied by the proportion of each component, achieving the effect of accurately measuring the amount of gas, component distribution, and gas production rate generated by the pyrolysis of a quantitative insulating oil at different temperatures. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a schematic diagram of the internal structure of the tubular furnace according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the external structure of the tubular furnace according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the results of hydrocarbon gas detection by a gas chromatograph according to an embodiment of the present invention; Figure 4 This is a flowchart of a quantitative experimental method for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature, according to an embodiment of the present invention.

[0021] The components are: 1. Material boat; 2. Insulation block; 3. Push rod; 4. Heating element; 5. Furnace tube; 6. Sealing flange; 7. Pressure sensor; 8. Insulation cover; 9. Air inlet; 10. Air outlet. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0024] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0025] To address the issues of low temperature control accuracy, uneven temperature distribution, and slow heating rate associated with conventional methods, a combination of... Figure 1 and Figure 2 A quantitative experimental system for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature is provided, including a tubular furnace, a gas chromatograph, and a vacuum pump. The tubular furnace includes a boat 1, a heat insulation block 2, a pusher rod 3, a furnace tube 5, and a vacuum pump. Heating elements 4 are evenly arranged around the middle periphery of the furnace tube to form a heating and constant temperature zone. Both ends of the furnace tube are equipped with sealing flanges 6. A pressure sensor 7 and a gas outlet 10 are installed on one sealing flange, and a gas inlet 9 is installed on the other sealing flange. The boat 1 contains a quantitative amount of insulating oil and is located on the left side inside the furnace tube. The heat insulation block 2 is located inside the furnace tube 5 and on the right side of the boat 1. The area on the right side of the heat insulation block 2 is the heating and constant temperature zone. The pusher rod 3 is movably connected to the furnace tube 5 to push the boat 1 and the heat insulation block 2 into the heating and constant temperature zone. The vacuum pump is connected to the furnace tube.

[0026] In one or more embodiments, the tubular furnace employs a pure fiber furnace chamber structure, and the heating element is a high-heat silicon carbide rod heating element. The silicon carbide rods are evenly arranged on the outer circumference of the middle part of the furnace tube for uniform heating. The uniform temperature zone is not less than 200 mm in length, the temperature difference is less than ±5℃, and the temperature is stable within ±1℃ of the set temperature, achieving a maximum temperature of 1500 degrees Celsius. The furnace tube is made of 99% corundum tube, with a temperature resistance of not less than 1700℃ and resistance to acid and alkali corrosion.

[0027] In some alternative embodiments, the furnace tube has an inner diameter of 32 mm and a length of 750 mm. The furnace tube dimensions are Φ40 (inner diameter 32) x 750 mm, which ensures sufficient space for the material boat and insulation block, as well as uniform pressure distribution during the experiment.

[0028] The material of the material boat 1 can be set according to the actual situation. For example, the material boat can be made of corundum.

[0029] At the start of the experiment, use a micro-syringe to inject an appropriate amount of insulating oil into the material boat. Place the heat insulation block from the left side of the furnace tube to the left side of the furnace tube, and then place the material boat to the left side of the heat insulation block to ensure that the material boat is in the low temperature zone of the furnace tube. Then seal the furnace tube with a sealing flange and connect the cooling pipe.

[0030] In this embodiment of the invention, water-cooling pipes are provided on both sides of the furnace tube to ensure that the temperature at both ends is below the phase transition temperature of the insulating oil. For example... Figure 2 As shown, the tubular furnace also includes a shell, and the furnace tubes are detachably connected inside the shell. An insulating protective cover 8 is provided on the outside of the shell.

[0031] In this embodiment, water cooling equipment and heat insulation blocks are added outside the high-temperature zone to ensure that the temperature at both ends of the tubular furnace is lower than the phase change temperature of the insulating oil. After the temperature of the high-temperature zone rises to the preset temperature, the material boat containing the insulating oil is quickly pushed from the low-temperature zone into the high-temperature zone using a pusher rod, so as to achieve rapid heating of the insulating oil from low temperature to high temperature.

[0032] Tubular furnaces are used to conduct isothermal pyrolysis experiments on insulating oil to collect pyrolysis gases and record pressure-time curves using an oscilloscope. The furnace tube is placed in the tubular furnace, and after evacuation by a vacuum pump, inert gas is injected to standard atmospheric pressure. The target temperature is set, and inert gas is continuously introduced during the heating process. Once the temperature in the isothermal zone of the tubular furnace reaches the target temperature, the inlet and outlet are closed, and the material boat and insulation block are pushed into the isothermal zone using a pusher rod to carry out the pyrolysis reaction and save the pressure data.

[0033] For example, use a micro-syringe to take an appropriate amount of insulating oil and put it into a corundum boat. Place the boat into the furnace tube, assemble the furnace tube, and place it into the tube furnace. Connect the outlet to a vacuum pump to extract the air from inside the furnace tube. Then close the outlet and open the inlet to inject inert gas. After the internal pressure reaches the standard atmospheric pressure, connect the outlet to a hose and then to a beaker containing pure water. Open the outlet. After the bubbles at the end of the hose stabilize, set the target temperature. The target temperature should be higher than 500℃ to ensure that the insulating oil can decompose quickly, and lower than the tube furnace's limit temperature of 1550℃. After setting the appropriate temperature, start heating. During the heating process, continuously circulate inert gas. During the heating process, the temperature near the material boat does not rise significantly due to the presence of the insulation block, preventing a phase change in the insulating oil. Once the temperature in the constant-temperature zone of the tubular furnace reaches the preset value, the inlet and outlet are closed. The material boat and insulation block are pushed into the constant-temperature zone using a pusher rod. After a period of time, the pyrolysis reaction is complete, and the pressure inside the furnace tube stabilizes. The outlet is then opened, and the gas is collected using a gas bag, with the pressure data recorded. After collecting the data, a cooling program is set. Once the temperature inside the furnace tube drops to room temperature, the furnace tube is removed and cleaned for use in the next experiment.

[0034] Inject inert gas. Once the internal pressure reaches the standard atmospheric pressure, connect the outlet to the hose and then to a beaker containing pure water. Open the outlet. After the rate of bubbles emerging from the end of the hose stabilizes, set the target temperature. The target temperature should be higher than 500℃ to ensure the decomposition of the insulating oil and lower than the limit temperature of the tubular furnace, which is 1550℃. Start heating at the target temperature. During the heating process, continuously pass inert gas.

[0035] A gas chromatograph is installed at the gas outlet to analyze the collected pyrolysis gases, such as... Figure 3The diagram illustrates the results of hydrocarbon gas detection using a gas chromatograph according to an embodiment of the present invention, thereby obtaining the components and proportions of the pyrolysis gas. Specifically, the collected gases are subjected to chromatographic analysis, with each sample being analyzed three times, and the final result is averaged. The proportions of different gas components are obtained through chromatographic analysis. After obtaining the proportions of gas components, the calculated... n 1( t ), V ( t ) and gas production rate v ( t Multiply by the percentage content of the corresponding component to obtain the gas production amount and gas production rate of each gas component.

[0036] The processor calculates the total gas volume and total gas production rate inside the tubular furnace based on the ideal gas equation and the pressure-time curve. The calculated total gas volume and total gas production rate are multiplied by the proportion of each component to obtain the gas production volume and gas production rate of each gas component.

[0037] For example, pressure sensors are used to record the pressure-time curve inside the furnace tube during the experiment. P ( t The initial amount of gaseous substance inside the furnace tube is denoted as . n 0, according to the ideal gas law P ( t ) V 0 =n ( t ) RT 0, temperature T 0 represents the set value and volume. V 0 represents the volume of the furnace tube. ，R Assuming the ideal gas constant, the pressure... P ( t Substitute the values ​​into the equation to solve for the amount of gaseous substance inside the furnace tube. n ( t ) = P ( t ) V / RT Then, the amount of gas produced can be determined. n 1( t )= n ( t )- n 0, finally obtaining the volume of the generated gas. V ( t ).

[0038] Obtain the amount of gas produced n 1( t ) and gas volume V ( t After that, the corresponding gas production rate is obtained by differentiating with respect to time. v (t)= dV (t ) / dt .

[0039] In one or more embodiments, a quantitative experimental method for the gas generation characteristics of transformer insulating oil pyrolysis under isothermal conditions includes: Step 1: Install the tubular furnace, evacuate the vacuum using a vacuum pump and then inject inert gas to the standard atmospheric pressure. Set the target temperature and continuously introduce inert gas during the heating process. Once the temperature in the constant temperature zone of the tubular furnace reaches the target temperature, close the gas passage and use a pusher rod to push the material boat and insulation block into the heating constant temperature zone to carry out the pyrolysis reaction. After the pressure inside the furnace tube stabilizes, collect the pyrolysis gas and record the pressure-time curve. Specifically, the tubular furnace is assembled, and additional holes are made on the sealing flanges at both ends of the furnace tube to install pressure sensors. Inside the furnace tube, on the far left, a boat containing a fixed amount of insulating oil is placed. To the right of the boat, a heat insulation block is placed to insulate the heat from the constant temperature zone. The area to the right of the heat insulation block is the heating zone.

[0040] Using a micro-syringe, take an appropriate amount of insulating oil and place it into a corundum boat. Place the boat into the furnace tube, and then place the furnace tube into the tube furnace. Connect the outlet to the vacuum pump to extract the air from inside the furnace tube. Then, close the outlet and open the inlet to inject inert gas. After the internal pressure reaches the standard atmospheric pressure, connect the outlet to a flexible tube and then to a beaker containing pure water. Open the outlet. After the bubbles at the end of the flexible tube stabilize, set the target temperature. The target temperature should be higher than the set temperature (e.g., 500℃) to ensure that the insulating oil can decompose quickly, and lower than the tube furnace's limit temperature of 1550℃. After setting the appropriate temperature, start heating. During the heating process, continuously circulate inert gas.

[0041] Once the temperature in the constant temperature zone of the tubular furnace reaches the preset value, close the gas inlet and outlet; use the pusher rod to push the material boat and insulation block into the constant temperature zone; after a period of time, the pyrolysis reaction is complete and the pressure inside the furnace tube is stable; open the outlet, collect the gas with a gas bag, and save the pressure data.

[0042] Step 2: Analyze the collected pyrolysis gas using a gas chromatograph to obtain the components and their proportions. In the specific implementation process, the collected gases were analyzed by gas chromatography. Each sample was analyzed at least three times, and the final results were averaged, as shown in Table 1 and... Figure 4 As shown.

[0043] Table 1. Results of gas chromatography analysis;

[0044] Step 3: Using the processor, calculate the total gas volume and total gas production rate inside the tubular furnace based on the ideal gas equation and the pressure-time curve. Multiply the calculated total gas volume and total gas production rate by the proportion of each component to obtain the gas production volume and gas production rate of each gas component.

[0045] After obtaining the gas composition percentage, the calculated n 1(t), V ( t ) and gas production rate v ( t Multiplying by the percentage content of the corresponding component yields the gas production amount and gas production rate of each gas component.

[0046] The pressure-time curve inside the furnace tube is denoted as: P ( t The initial amount of gaseous substance inside the furnace tube is denoted as . n 0, according to the ideal gas law P ( t ) V 0 =n ( t ) RT 0, temperature T 0 represents the set value and volume. V 0 represents the volume of the furnace tube. ，R Assuming the ideal gas constant, the pressure... P ( t Substitute the values ​​into the equation to solve for the amount of gaseous substance inside the furnace tube. n ( t ) = P ( t ) V / RT Then, the amount of gas produced can be determined. n 1( t )= n ( t )- n 0, finally obtaining the volume of the generated gas. V ( t ); t For time.

[0047] Obtain the amount of gas produced n 1( t ) and gas volume V ( t After that, the corresponding gas production rate is obtained by differentiating with respect to time. v (t)= dV ( t ) / dt .

[0048] Based on the ideal gas law P(t)V = n(t)RT, where V is the furnace tube volume, T is the set temperature, and R is the ideal gas constant, a pressure sensor records the P(t) curve in real time, dynamically solving for the amount of gas n(t), and then calculating the gas production rate. n 1( t )= n ( t )- n 0, gas production rate v(t) = dV(t) / dt; n 0 represents the initial gas volume. This mechanism upgrades static gas collection to dynamic continuous monitoring, avoiding the limitations of traditional methods that only capture the instantaneous gas production after discharge, and achieving real-time quantification of the gas production rate for the first time. The gas chromatograph repeatedly analyzes the gas sample at least three times and takes the average value to obtain the percentage content of each component (such as hydrocarbon gases); the calculated... n 1( t By multiplying v(t) by the percentage content of each component, the gas production rate and gas production rate of each component can be accurately obtained (e.g., C2H2 gas production = ...). n 1( t (×C2H2%). This closed-loop design eliminates random errors from single detections, resulting in a repeatability error of less than 3% for component distribution data, significantly superior to the qualitative descriptions of existing methods. The synergistic effect of the above-mentioned techniques enables this invention to accurately measure the pyrolysis gas production characteristics of insulating oil at constant temperatures (600℃~1500℃): gas quantity n 1( t The method achieves dynamic and quantitative output of component distribution (such as the C2H2 / H4 / H2 ratio) and gas production rate v(t), providing high-precision experimental data for bubble evolution modeling, pressure prediction, and fault diagnosis in the internal discharge process of oil-immersed power equipment. For example, in a 650℃ isothermal experiment, the H2 gas production rate measured by this method (0.28 mL / min) deviates by less than 5% compared with the traditional method (0.15 mL / min), and the component ratio error is controlled within ±2%, completely solving the problem of gas production characteristic distortion caused by large temperature fluctuations and low detection accuracy in existing methods.

[0049] Repeat the above operations to conduct isothermal pyrolysis experiments at different temperatures, and measure the amount of gas, component distribution and gas production rate generated by the pyrolysis of insulating oil at different temperatures.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A quantitative experimental system for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature, characterized in that, include: The system comprises a tubular furnace, a gas chromatograph, and a processor. The tubular furnace includes a furnace tube, a material boat, a heat insulation block, a pusher rod, and a vacuum pump. Heating elements are evenly arranged around the periphery of the furnace tube to form a constant-temperature heating zone. Both ends of the furnace tube are equipped with sealing flanges; one sealing flange is equipped with a pressure sensor and an outlet, while the other sealing flange is equipped with an inlet. The material boat contains a measured amount of insulating oil and is located inside the furnace tube on the left side. The heat insulation block is located inside the furnace tube on the right side of the material boat, and the area to the right of the heat insulation block constitutes the constant-temperature heating zone. The pusher rod is movably connected to the furnace tube to push the material boat and the heat insulation block into the constant-temperature heating zone. The vacuum pump is connected to the furnace tube. The gas chromatograph is connected to the gas outlet and is used to analyze the composition and proportion of the pyrolysis gas in the furnace tube; both the gas chromatograph and the pressure sensor are connected to the processor. The processor is used to generate a pressure-time curve based on the pressure of the cracked gas inside the furnace tube detected by the pressure sensor, and to calculate the total gas volume and total gas production rate-time curve inside the tubular furnace using the ideal gas equation. Then, based on the component proportion of the cracked gas, it obtains the gas production volume and gas production rate of each gas component.

2. The quantitative experimental system for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature as described in claim 1, characterized in that, Water-cooled pipes are provided on both sides of the furnace tube to ensure that the temperature at both ends is lower than the phase change temperature of the insulating oil.

3. The quantitative experimental system for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature as described in claim 1, characterized in that, The tubular furnace also includes a shell, and the furnace tubes are detachably connected inside the shell.

4. A quantitative experimental method for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature, characterized in that, The quantitative experimental system for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature as described in any one of claims 1-3 includes: Install a tubular furnace, evacuate the furnace using a vacuum pump, inject inert gas to the standard atmospheric pressure, set the target temperature, and continuously introduce inert gas during the heating process. Once the temperature in the constant temperature zone of the tubular furnace reaches the target temperature, close the gas passage, and use a pusher rod to push the material boat and insulation block into the heating constant temperature zone to carry out the pyrolysis reaction. After the pressure inside the furnace tube stabilizes, collect the pyrolysis gas and record the pressure-time curve. The collected pyrolysis gas was analyzed using a gas chromatograph to obtain the components and their proportions. The processor calculates the total gas volume and total gas production rate inside the tubular furnace based on the ideal gas equation and the pressure-time curve. The calculated total gas volume and total gas production rate are then multiplied by the proportion of each component to obtain the gas production volume and gas production rate of each gas component.

5. The quantitative experimental method for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature as described in claim 4, characterized in that, The pressure-time curve inside the furnace tube is denoted as: P ( t The initial amount of gaseous substance inside the furnace tube is denoted as . n 0, according to the ideal gas law P ( t ) V 0 =n ( t ) RT 0, temperature T 0 represents the set value and volume. V 0 represents the volume of the furnace tube. ，R Assuming the ideal gas constant, the pressure... P ( t Substitute the values ​​into the equation to solve for the amount of gaseous substance inside the furnace tube. n ( t ) = P ( t ) V / RT Then, the amount of gas produced can be determined. n 1( t )= n ( t )- n 0, finally obtaining the volume of the generated gas. V ( t ); t For time.

6. The quantitative experimental method for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature as described in claim 5, characterized in that, Obtain the amount of gas produced n 1( t ) and gas volume V ( t After that, the corresponding gas production rate is obtained by differentiating with respect to time. v (t)= dV ( t ) / dt .

7. The quantitative experimental method for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature as described in claim 4, characterized in that, The process of analyzing the collected pyrolysis gases using a gas chromatograph is as follows: The collected pyrolysis gases were subjected to chromatographic analysis. Each sample was tested at least three times, and the final result was the average value. The content of different gas components was obtained through chromatographic analysis.

8. The quantitative experimental method for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature as described in claim 4, characterized in that, The target temperature is below the limit temperature of the tubular furnace.

9. The quantitative experimental method for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature as described in claim 4, characterized in that, Once the temperature in the heating constant temperature zone of the tubular furnace reaches the target temperature value, close the air inlet and outlet.

10. The quantitative experimental method for the gas generation characteristics of transformer insulating oil pyrolysis under constant temperature as described in claim 4, characterized in that, At the start of the experiment, insulating oil was injected into the material boat, and the heat insulation block was placed from the left side of the furnace tube to the left side of the furnace tube. Then the material boat was placed to the left of the heat insulation block to ensure that the material boat was in the low temperature zone of the furnace tube.

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