Argon removal method used after argon arc welding of electrical penetration assembly cylinder

Abstract

The invention discloses a method for removing argon after argon arc welding of an electrical penetration assembly barrel. The method comprises the following steps that S1, a nitrogen tank and a helium tank are installed, specifically, the nitrogen tank and the helium tank are installed at the end of a framework; s2, helium leak detection test: helium is injected into the coil to detect whether leakage occurs; s3, overall sealing inspection: injecting nitrogen into the coil to detect whether the overall sealing performance is good or not; s4, a vacuum pump and a carbon dioxide tank are installed, wherein the vacuum pump and the carbon dioxide tank are installed and connected; s5, argon vacuum extraction is conducted, specifically, the coil is vacuumized; injecting high-temperature carbon dioxide gas; vacuumizing again; and S6, the vacuum pump and the carbon dioxide tank are dismantled. And after argon arc welding is completed, redundant argon is eliminated, so that the coil is protected, and the safety of a working environment is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of electrical penetrations, in particular to a method for removing argon after argon arc welding of an electrical penetration cylinder. Background Art

[0002] The control rod drive mechanism on the top cover of the pressure vessel of a pressurized water reactor operates in a high temperature, high pressure, and strong radiation environment for a long time. Therefore, the electromagnetic coil installed in the cylinder of the electrical penetration must have comprehensive characteristics such as high temperature resistance, radiation resistance, and earthquake resistance. The lead wire at one end of the electromagnetic coil and the cylinder of the electrical penetration are usually sealed and fixed by welding; since argon arc welding has a stable arc and high welding quality; the argon gas in the gas shielding agent can effectively squeeze harmful substances such as oxygen and nitrogen around the welding position out of the welding area, thereby ensuring high-quality welding; therefore, the prior art, such as a Chinese patent discloses an electromagnetic coil for a nuclear power plant control rod drive mechanism (authorization announcement number CN114420401B), which usually uses argon arc welding when sealing and welding the junction between the terminal and the inner cylinder and the outer frame.

[0003] However, during the argon arc welding process, a large amount of argon gas will enter the electromagnetic coil. Since the argon gas molecules are extremely small and the thermal conductivity is extremely high, the temperature of the electromagnetic coil will be very unstable. Especially in the case of high power output, the heat generated by the control rod drive mechanism will increase rapidly in a short period of time, causing the electromagnetic coil to oxidize and harden, shortening the service life of the electromagnetic coil. Summary of the invention

[0004] The purpose of the present invention is to provide a method for removing argon after argon arc welding of an electrical penetration barrel to address the above-mentioned problems. After argon arc welding is completed, excess argon can be removed to protect the coil and ensure the safety of the working environment.

[0005] The technical solution adopted by the present invention is as follows: A method for removing argon after argon arc welding of an electrical penetration barrel comprises the following steps: S1. Installation of nitrogen tank and helium tank: Install nitrogen tank and helium tank on the welded device and connect them to the coil in the inner cavity of the device; S2. Helium leak test: Inject helium into the coil to detect leakage; S3. Overall sealing inspection: Inject nitrogen into the coil to check whether the overall sealing performance is good; S4. Installation of vacuum pump and carbon dioxide tank: Install and connect the vacuum pump and carbon dioxide tank; S5, argon vacuum extraction: evacuate the coil; inject high-temperature carbon dioxide gas; evacuate again; S6. Remove the vacuum pump and carbon dioxide tank.

[0006] Specifically, the nitrogen tank and helium tank are installed to prepare for the subsequent helium leak test and overall sealing inspection. Nitrogen and helium are both inert gases that will not react chemically with the coil material. They have different physical properties and are suitable for detecting leaks and sealing performance. Helium is a light inert gas that can easily escape through tiny gaps, making it very suitable for detecting small leaks. By injecting helium into the coil and then detecting whether there is a leak, the leakage of the coil and its connection parts can be accurately detected. By detecting leaks, the accuracy of the test results during the overall sealing inspection in step S3 is ensured. And because the leak point will affect the vacuum degree, the result of the leak detection will affect the effect of vacuuming in step S5. Nitrogen is used as a pressure medium here, and nitrogen is injected into the coil. The sealing of the entire system is evaluated by detecting the pressure change of nitrogen or using nitrogen as a tracer gas. If the pressure of nitrogen remains stable, it means that the sealing performance is good; if the pressure drops, there may be a leak. Good sealing is a prerequisite for successful vacuuming, and the result of the overall sealing inspection ensures the effectiveness of vacuuming in step S5. The vacuum pump and CO2 tank are installed for the next step of argon vacuum extraction. The vacuum pump is used to extract the air and residual argon inside the coil, while the CO2 tank is used for subsequent atmosphere replacement. First, the vacuum pump is used to evacuate the coil to remove the residual argon and other gases inside. Secondly, the injection of CO2 can dilute the remaining argon in the cylinder. Since the molecular weight of CO2 is greater than that of argon, it can push argon molecules under a certain pressure, thereby achieving further dilution. At the same time, the diffusion rate of CO2 is usually higher than that of argon, and the mixture of CO2 and argon is easier to be removed by vacuum than pure argon. After CO2 injection, vacuuming again can more effectively remove argon from the mixed gas. After completing the argon removal process, remove related equipment such as vacuum pumps, CO2 tanks and pressure gauges, end the argon removal operation, and restore the equipment to normal working condition. This step also ensures the safety of the working area and prevents misoperation and equipment damage.

[0007] Optionally, the following steps may be included: S1. Installation of nitrogen and helium tanks: Open a threaded hole at the end of the frame and install one end of the three-way joint in the threaded hole; then install valves and pressure gauges on the other two ends of the three-way joint, and then connect them to the nitrogen and helium tanks through the corresponding air pipes; by opening a threaded hole at the end of the frame and installing a three-way joint, it is more convenient to switch the supply of different gases, which improves the flexibility and efficiency of operation. Installing valves and pressure gauges can accurately control the flow and pressure of the gas to ensure the accuracy and safety of the test.

[0008] S2. Helium leak test: Open the helium tank and inject helium into the cylinder and frame of the electrical penetration where the electromagnetic coil is located, perform a pressure test, and maintain the pressure; then, use the helium leak detector to perform fixed-point detection on each sealing position on the cylinder and frame of the electrical penetration to determine whether there is a leak at the sealing position. If there is a leak, it means that the quality of the cylinder of the electrical penetration is unqualified and needs to be replaced or repaired; if there is no leak, the helium is discharged through the corresponding valve; the helium leak test performs a pressure test and maintains the pressure, which can simulate the pressure state under actual working conditions and detect small leaks more effectively. Fixed-point detection helps to accurately identify the leak location and improve the accuracy of fault diagnosis. If there is no leak, the helium is discharged through the valve, which is convenient and safe to operate.

[0009] S3. Overall sealing inspection: open the nitrogen tank, inject nitrogen into the cylinder and frame of the electrical penetration component where the electromagnetic coil is located, conduct a pressure test, observe the pressure change, and determine whether the overall sealing performance of the electrical penetration component cylinder meets the set requirements. If not, it means that the quality of the electrical penetration component cylinder is unqualified and needs to be replaced or repaired; if it meets, discharge the nitrogen through the corresponding valve; Overall sealing inspection By injecting nitrogen for pressure test and observing the pressure change, the overall sealing performance of the electrical penetration component cylinder can be comprehensively evaluated.

[0010] S4. Installation of vacuum pump and carbon dioxide tank: Remove the nitrogen tank and helium tank from the three-way joint; then connect them to the vacuum pump and carbon dioxide tank through the corresponding air pipes; remove the nitrogen tank and helium tank, and replace them with vacuum pump and carbon dioxide tank, which can quickly change the operation steps, reduce operation time and improve work efficiency.

[0011] S5. Vacuum extraction of argon: Start the vacuum pump to evacuate the cylinder and frame of the electrical penetration part where the electromagnetic coil is located to discharge the residual argon inside the electromagnetic coil; inject heated high-temperature carbon dioxide gas into it through the carbon dioxide tank, and then start the vacuum pump to extract the carbon dioxide gas, and repeat the above steps to discharge the residual argon inside the electromagnetic coil; vacuuming first and then injecting high-temperature carbon dioxide gas can more thoroughly discharge the residual argon, and high-temperature carbon dioxide gas helps to accelerate the removal of residual gas. Start the vacuum pump again to extract carbon dioxide to ensure the final cleanliness.

[0012] S6. Close the valve on the three-way joint and remove the vacuum pump, carbon dioxide tank and pressure gauge. Closing the valve can prevent gas backflow and ensure that the system remains sealed after the equipment is removed. Removing the relevant equipment restores the original appearance of the work area and improves the safety and cleanliness of the workplace.

[0013] Optionally, in step S1, a high-temperature resistant plugging agent package needs to be pre-buried, and magnets with opposite magnetic properties are installed on the high-temperature resistant plugging agent package and the three-way joint respectively; the high-temperature resistant plugging agent package is pre-buried in an appropriate position, and the magnets with opposite magnetic properties ensure that the plugging agent package can be accurately adsorbed to a specific position of the three-way joint when needed.

[0014] In step S5, as the vacuum is drawn, the high-temperature resistant plugging agent package is adsorbed onto the outside of the bottom of the tee joint; during the vacuum drawing process, the high-temperature resistant plugging agent package is adsorbed onto the outside of the bottom of the tee joint by utilizing the attraction of the magnet. The purpose of this is to ensure that when the equipment is dismantled, the plugging agent package can be accurately positioned near the threaded hole in preparation for plugging.

[0015] In step S6, as the vacuum pump, the carbon dioxide tank and the pressure gauge are removed, the high temperature plugging agent package is taken out to block the threaded hole, and the high temperature plugging agent in the high temperature plugging agent package is manually released to achieve rapid sealing. In the process of removing the vacuum pump, the carbon dioxide tank and the pressure gauge, the high temperature plugging agent package is taken out as the three-way joint is removed, and the threaded hole is accurately blocked. Manually releasing the high temperature plugging agent in the plugging agent package can quickly form a seal to prevent gas leakage and external impurities from entering.

[0016] Optionally, S7 is also available, which is to remove the excess high-temperature resistant plugging agent at the end of the frame. If there is too much plugging agent, it may interfere with the assembly of the frame and other components. Removing the excess plugging agent can ensure the correct fit between the components. And removing the excess plugging agent can avoid potential safety hazards caused by the shedding of the plugging agent in subsequent operations, ensuring the overall quality, safety and reliability of the product.

[0017] Optionally, in step S1, the range of the pressure gauge is 1.5 to 2.5 times the test pressure; this provides sufficient safety margin to help prevent damage to the pressure gauge due to excessive pressure, and ensures that the pressure gauge can read accurately without exceeding its range during normal operation and possible pressure fluctuations. The accuracy level of the pressure gauge is ≥ 1.6. This ensures the accuracy of the measurement results and helps to accurately determine whether the system has achieved the expected sealing standards.

[0018] Optionally, in the S2 step, the holding pressure is 350-450 kPa, which can effectively detect tiny leaks. Too high a pressure may cause deformation or damage to the coil material, while too low a pressure may not be able to detect tiny leaks. The holding time is 10-15 minutes. Helium is allowed to fully penetrate into possible leaks, thereby improving the sensitivity and accuracy of detection. Too short a holding time may not be able to fully detect all leaks, while too long a holding time may result in reduced operating efficiency.

[0019] Optionally, in step S3, the specific steps of the overall sealing inspection are as follows: S31. In an environment of 20-35°C, first inject 150-200kPa of nitrogen into the cylinder and frame of the electrical penetration component where the electromagnetic coil is located through a nitrogen tank at a rate of 10-15kPa / min; by controlling the rate and pressure of nitrogen injection, a stable pressure environment can be established in the cylinder to prepare for the next step of gradual pressurization.

[0020] S32. Next, the pressure is increased to 10 kPa, and then stopped for 1 minute, and then gradually increased to 350-450 kPa. By gradually increasing the pressure, the pressure change under actual working conditions is simulated, and the sealing performance of the cylinder of the electrical penetration piece can be more comprehensively evaluated.

[0021] S33. After maintaining pressure for 72 hours, observe the pressure drop; if the pressure drop is ≤10kPa, it is judged that the overall sealing performance meets the set requirements and the quality is qualified; if the pressure drop is greater than 10kPa, it is judged that the overall sealing performance does not meet the set requirements and the quality is unqualified. Long-term pressure maintenance observation can detect potential leaks and evaluate its sealing performance under long-term pressure. The 10kPa pressure drop threshold ensures the reliability of electrical penetrations in practical applications.

[0022] Alternatively, in the step S5, the specific steps of vacuum extraction of argon are as follows: S51. Use a vacuum pump to evacuate the electrical penetration part cylinder and frame where the electromagnetic coil is located to 15-20 kPa, and then inject high-temperature carbon dioxide gas to 101 kPa; after maintaining the pressure for 24 hours, evacuate to 8-12 Pa, and repeat for no less than 3 times; through the process of multiple evacuations and injections of high-temperature carbon dioxide gas, argon can be effectively pushed out of the closed space. High-temperature carbon dioxide gas has a higher diffusion rate and thermal conductivity, which helps to further remove residual argon. Maintaining the pressure for 24 hours helps the argon and carbon dioxide gases to be fully mixed and diffused.

[0023] S52. Use an argon detector to detect the gas extracted for the last time to determine whether the argon content in the gas is higher than the set value. If it is not higher than the set value, inject high-temperature carbon dioxide gas to 101kPa, and then evacuate to 1Pa; if it is higher than the set value, repeat step S51 until the argon content in the extracted gas is no higher than the set value. The detection of the argon detector can ensure that the argon content meets the set standard. If the argon content is still higher than the set value, it is necessary to repeat step S51 until the argon content meets the requirement. This ensures the high cleanliness and low pollution of the internal environment of the electrical penetration barrel, which is crucial to the long-term reliability and performance of the product.

[0024] Optionally, in step S5, the temperature of the carbon dioxide gas is 150-170° C. High-temperature carbon dioxide gas has higher molecular kinetic energy, so its diffusion speed is faster, and the carbon dioxide gas can more effectively push argon molecules to escape from the closed space, thereby improving the efficiency of argon removal.

[0025] Optionally, in the steps S51 and S52, the vacuuming method is intermittent pumping, that is, pumping 5 kPa, stopping for 2 minutes, until the vacuuming reaches the set value. Intermittent pumping can prevent the coil and the device from being subjected to too high a vacuum degree in a short time, thereby avoiding overheating and deformation of the material due to rapid temperature changes. It also helps to form a uniform vacuum environment inside the cylinder of the electrical penetration, which helps to remove argon more evenly and improve the removal efficiency.

[0026] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: The present invention provides a method for removing argon after argon arc welding of an electrical penetration barrel. First, a helium leak test and an overall sealing inspection test are used to determine whether the sealing performance of the electrical penetration barrel meets the requirements; then, a vacuum is drawn into the electrical penetration barrel and the frame where the coil is located by a vacuum pump, and then, high-temperature carbon dioxide gas is injected, and then the carbon dioxide gas is extracted to discharge the argon remaining in the coil; thereby greatly improving the service life of the electrical penetration barrel in a high-temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 It is a schematic diagram of the structure of the corresponding device for argon removal.

[0028] Markings in the figure: 1-electrical penetration cylinder, 2-frame, 3-electromagnetic coil, 4-lead wire, 5-welding port, 6-pressure gauge, 7-valve, 8-tee joint. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0030] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0031] Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0032] In this solution, the device used includes an I-shaped rotating frame 2, an electromagnetic coil 3 is wound on the frame, an electrical penetration member cylinder 1 is welded to the outside of the frame 2, and the cavity between the frame 2 and the electrical penetration member cylinder 1 is used to enclose the electromagnetic coil 3. A three-way joint 8 is provided on the frame 2, and the three-way joint 8 is connected to the cavity between the frame 2 and the electrical penetration member cylinder 1. The lead wire 4 is welded at the outlet of the electrical penetration member cylinder 1 and the frame 2.

[0033] Embodiment 1 See also Figure 1 In an embodiment of the present invention, a method for removing argon after argon arc welding of an electrical penetration barrel comprises the following steps: S1. Installation of nitrogen tank and helium tank: a threaded hole is opened at the end of the frame 2, and one end of the three-way joint 8 is installed in the threaded hole; then, a valve 7 and a pressure gauge 6 are installed on the other two ends of the three-way joint 8, and then connected to the nitrogen tank and the helium tank through corresponding air pipes respectively; S2, helium leak test: open the helium tank, inject helium into the electrical penetration member cylinder 1 and the frame 2 where the electromagnetic coil 3 is located until the pressure reaches 350 kPa, and maintain the pressure for 15 minutes; then, use the helium leak detector to perform fixed-point detection on each sealing position on the electrical penetration member cylinder 1 and the frame 2 to determine whether there is a leak at the sealing position. If there is a leak, it means that the quality of the electrical penetration member cylinder is unqualified and needs to be replaced or repaired; if there is no leak, the helium is discharged through the corresponding valve 7; S3. Overall sealing inspection: Open the nitrogen tank and, at 20°C, first inject 200 kPa of nitrogen into the electrical penetration member cylinder 1 and the frame 2 where the electromagnetic coil 3 is located at a rate of 15 kPa / min; then, gradually pressurize to 450 kPa in the manner of filling 10 kPa and stopping for 1 minute; after maintaining the pressure for 72 hours, observe the pressure drop; when the direct pressure drop is ≤10 kPa, discharge the nitrogen through the corresponding valve 7; S4. Installation of vacuum pump and carbon dioxide tank: remove the nitrogen tank and helium tank from the three-way joint 8; and then connect them to the vacuum pump and carbon dioxide tank through corresponding air pipes respectively; S5. Start the vacuum pump, and evacuate the electrical penetration member cylinder 1 and the frame 2 where the electromagnetic coil 3 is located to 20 kPa by evacuating 5 kPa and stopping for 2 minutes, and then inject 150°C carbon dioxide gas to 101 kPa; after maintaining the pressure for 24 hours, evacuate to 12 Pa, and repeat 3 times; then use an argon detector to detect the gas extracted for the last time, and when the argon content in the gas is not higher than the set value, inject carbon dioxide gas to 101 kPa, and then evacuate to 1 Pa; S6. Close the valve 7 on the three-way connector 8, and remove the vacuum pump, the carbon dioxide tank and the pressure gauge 6.

[0034] Embodiment 2 See also Figure 1 In an embodiment of the present invention, a method for removing argon after argon arc welding of an electrical penetration barrel comprises the following steps: S1. Installation of nitrogen tank and helium tank: a threaded hole is opened at the end of the frame 2, and one end of the three-way joint 8 is installed in the threaded hole; then, a valve 7 and a pressure gauge 6 are installed on the other two ends of the three-way joint 8, and then connected to the nitrogen tank and the helium tank through corresponding air pipes respectively; S2, helium leak test: open the helium tank, inject helium into the electrical penetration member cylinder 1 and the frame 2 where the electromagnetic coil 3 is located until the pressure reaches 400 kPa, and maintain the pressure for 12 minutes; then, use the helium leak detector to perform fixed-point detection on each sealing position on the electrical penetration member cylinder 1 and the frame 2 to determine whether there is a leak at the sealing position. If there is a leak, it means that the quality of the electrical penetration member cylinder is unqualified and needs to be replaced or repaired; if there is no leak, the helium is discharged through the corresponding valve 7; S3. Overall sealing inspection: Open the nitrogen tank and, at 30°C, first inject 180 kPa of nitrogen into the electrical penetration member cylinder 1 and the frame 2 where the electromagnetic coil 3 is located at a rate of 12 kPa / min; then, gradually pressurize to 400 kPa in the manner of filling 10 kPa and stopping for 1 minute; after maintaining the pressure for 72 hours, observe the pressure drop; when the direct pressure drop is ≤10 kPa, discharge the nitrogen through the corresponding valve 7; S4. Installation of vacuum pump and carbon dioxide tank: remove the nitrogen tank and helium tank from the three-way joint 8; and then connect them to the vacuum pump and carbon dioxide tank through corresponding air pipes respectively; S5. Start the vacuum pump, and evacuate the electrical penetration member cylinder 1 and the frame 2 where the electromagnetic coil 3 is located to 18 kPa by evacuating 5 kPa and stopping for 2 minutes, and then inject 160°C carbon dioxide gas to 101 kPa; after maintaining the pressure for 24 hours, evacuate to 10 Pa, and repeat 3 times; then use an argon detector to detect the gas extracted for the last time, and when the argon content in the gas is not higher than the set value, inject carbon dioxide gas to 101 kPa, and then evacuate to 1 Pa; S6. Close the valve 7 on the three-way connector 8, and remove the vacuum pump, the carbon dioxide tank and the pressure gauge 6.

[0035] Embodiment 3 See also Figure 1 In an embodiment of the present invention, a method for removing argon after argon arc welding of an electrical penetration barrel comprises the following steps: S1. Installation of nitrogen tank and helium tank: a threaded hole is opened at the end of the frame 2, and one end of the three-way joint 8 is installed in the threaded hole; then, a valve 7 and a pressure gauge 6 are installed on the other two ends of the three-way joint 8, and then connected to the nitrogen tank and the helium tank through corresponding air pipes respectively; S2, helium leak test: open the helium tank, inject helium into the electrical penetration member cylinder 1 and the frame 2 where the electromagnetic coil 3 is located until the pressure reaches 450 kPa, and maintain the pressure for 10 minutes; then, use the helium leak detector to perform fixed-point detection on each sealing position on the electrical penetration member cylinder 1 and the frame 2 to determine whether there is a leak at the sealing position. If there is a leak, it means that the quality of the electrical penetration member cylinder is unqualified and needs to be replaced or repaired; if there is no leak, the helium is discharged through the corresponding valve 7; S3. Overall sealing inspection: Open the nitrogen tank and, at 35°C, first inject 150 kPa of nitrogen into the electrical penetration member cylinder 1 and the frame 2 where the electromagnetic coil 3 is located at a rate of 10 kPa / min; then, gradually pressurize to 350 kPa in the manner of filling 10 kPa and stopping for 1 min; after maintaining the pressure for 72 hours, observe the pressure drop; when the direct pressure drop is ≤10 kPa, discharge the nitrogen through the corresponding valve 7; S4. Installation of vacuum pump and carbon dioxide tank: remove the nitrogen tank and helium tank from the three-way joint 8; and then connect them to the vacuum pump and carbon dioxide tank through corresponding air pipes respectively; S5. Start the vacuum pump, and evacuate the electrical penetration member cylinder 1 and the frame 2 where the electromagnetic coil 3 is located to 15 kPa by evacuating 5 kPa and stopping for 2 minutes, and then inject 170°C carbon dioxide gas to 101 kPa; after maintaining the pressure for 24 hours, evacuate to 8 Pa, and repeat 3 times; then use an argon detector to detect the gas extracted for the last time, and when the argon content in the gas is not higher than the set value, inject carbon dioxide gas to 101 kPa, and then evacuate to 1 Pa; S6. Close the valve 7 on the three-way connector 8, and remove the vacuum pump, the carbon dioxide tank and the pressure gauge 6.

[0036] Preferably, in Example 1, Example 2 and Example 3, the measuring range of the pressure gauge 6 is 1.5 to 2.5 times of the test pressure; the accuracy grade of the pressure gauge 6 is ≥ Grade 1.6.

[0037] In order to better illustrate the technical effects of the present invention, the following embodiments are described: When the lead wire 4 is welded to the outlet of the electrical penetration member cylinder 1 and the frame 2 by argon arc welding, a large amount of argon gas will enter the electrical penetration member cylinder 1 and the frame 2 where the electromagnetic coil 3 is located from the welding port 5; therefore, the electrical penetration member cylinder after welding is not treated in any way, as a comparative example 1; In the laboratory, the electrical penetration member cylinders prepared in Example 1, Example 2, Example 3 and Comparative Example 1 were subjected to aging tests respectively, the test environment was 300° C., 12 cycles of aging were performed using 220Vac power supply, and each cycle was set to be powered on for 10 hours and off for 1 hour; The appearance of the coil plastic-sealed housing and the insulation hardness (unit: kgf / mm) of the first embodiment, the second embodiment, the third embodiment and the comparative example 1 were observed before and after aging. 2 ) and oxidation induction time (unit: min) and are recorded in Table 1 below.

[0038] Table 1 Coil performance analysis table

[0039] It can be concluded from Table 1 above that before aging, the insulation hardness and oxidation induction time of the coil plastic-sealed shells in Example 1, Example 2, Example 3 and Comparative Example 1 have no significant difference and are comparable, but after 12 aging cycles, the insulation hardness and oxidation induction time of the coil plastic-sealed shells in Example 1, Example 2 and Example 3 are significantly less than those in Comparative Example 1; Before aging, the surfaces of the plastic-sealed shells of the coils in Example 1, Example 2, Example 3 and Comparative Example 1 were all smooth; however, after 12 aging cycles, the surfaces of the coils in Example 1, Example 2 and Example 3 were still relatively smooth, while the surface of the coil in Comparative Example 1 had already developed fine cracks; It can be further concluded that the argon removal method adopted by the present invention can significantly increase the service life of the electrical penetration member cylinder.

[0040] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for removing argon after argon arc welding of an electrical penetration barrel, characterized in that: The following steps are involved: S1. Installation of nitrogen tank and helium tank: Install nitrogen tank and helium tank at the end of the frame (2); S2. Helium leak test: Inject helium into the coil to detect leakage; S3. Overall sealing inspection: Inject nitrogen into the coil to check whether the overall sealing performance is good; S4. Installation of vacuum pump and carbon dioxide tank: Install and connect the vacuum pump and carbon dioxide tank; S5, argon vacuum extraction: evacuate the coil; inject high-temperature carbon dioxide gas; evacuate again; S6. Remove the vacuum pump and carbon dioxide tank.

2. A method for removing argon after argon arc welding of an electrical penetration barrel (1) according to claim 1, characterized in that: The following steps are involved: S1. Installation of nitrogen tank and helium tank: a threaded hole is opened at the end of the frame (2), and one end of the three-way joint (8) is installed in the threaded hole; then, a valve (7) and a pressure gauge (6) are installed on the other two ends of the three-way joint (8), and then connected to the nitrogen tank and the helium tank respectively through corresponding air pipes; S2, helium leak test: open the helium tank, inject helium into the electrical penetration member cylinder (1) and the frame (2) where the electromagnetic coil (3) is located, perform a pressure test, and maintain the pressure; then, use a helium leak detector to perform a fixed-point detection on each sealing position on the electrical penetration member cylinder (1) and the frame (2) to determine whether there is a leak at the sealing position. If there is a leak, it means that the quality of the electrical penetration member cylinder (1) is unqualified and needs to be replaced or repaired; if there is no leak, the helium is discharged through the corresponding valve (7); S3. Overall sealing inspection: open the nitrogen tank, inject nitrogen into the electrical penetration member cylinder (1) and the frame (2) where the electromagnetic coil (3) is located, conduct a pressure test, observe the pressure change, and judge whether the overall sealing performance of the electrical penetration member cylinder (1) meets the set requirements. If not, it means that the quality of the electrical penetration member cylinder (1) is unqualified and needs to be replaced or repaired; if it meets, discharge the nitrogen through the corresponding valve (7); S4. Installation of vacuum pump and carbon dioxide tank: remove the nitrogen tank and helium tank from the three-way joint (8); and then connect them to the vacuum pump and carbon dioxide tank through corresponding air pipes respectively; S5, argon vacuum extraction: start the vacuum pump to evacuate the electrical penetration member cylinder (1) and the frame (2) where the electromagnetic coil (3) is located, so as to discharge the argon gas remaining inside the electromagnetic coil (3); inject heated high-temperature carbon dioxide gas into the cylinder through a carbon dioxide tank, and then start the vacuum pump to extract the carbon dioxide gas, and repeat the above steps to discharge the argon gas remaining inside the electromagnetic coil (3); S6. Close the valve (7) on the three-way connector (8), and remove the vacuum pump, carbon dioxide tank, and pressure gauge (6).

3. A method for removing argon after argon arc welding of an electrical penetration barrel (1) according to claim 1, characterized in that: In step S1, a high temperature resistant plugging agent package needs to be pre-buried, and magnets with opposite magnetic properties are respectively installed on the high temperature resistant plugging agent package and the three-way joint (8); In step S5, as the vacuum is drawn, the high temperature resistant plugging agent package is adsorbed on the outside of the bottom of the three-way joint (8); In step S6, as the removal occurs, the high temperature resistant plugging agent package is taken out to plug the threaded hole, and the high temperature resistant plugging agent in the high temperature resistant plugging agent package is manually released to achieve rapid sealing.

4. A method for removing argon after argon arc welding of an electrical penetration barrel (1) according to claim 1, characterized in that: The process also includes S7, removing excess high temperature resistant plugging agent from the end of the frame (2).

5. The method for removing argon after argon arc welding of an electrical penetration barrel (1) according to claim 1, characterized in that: In step S1, the measuring range of the pressure gauge (6) is 1.5 to 2.5 times the test pressure; the accuracy grade of the pressure gauge (6) is ≥ grade 1.

6.

6. A method for removing argon after argon arc welding of an electrical penetration barrel (1) according to claim 1, characterized in that: In the step S2, the holding pressure is 350-450 kPa, and the holding time is 10-15 min.

7. A method for removing argon after argon arc welding of an electrical penetration barrel (1) according to claim 1, characterized in that: In the step S3, the specific steps of the overall sealing inspection are as follows: S31. In an environment of 20 to 35° C., firstly, inject 150 to 200 kPa of nitrogen gas at a rate of 10 to 15 kPa / min into the electrical penetration member cylinder (1) and the frame (2) where the electromagnetic coil (3) is located through a nitrogen tank; S32, then, fill with air at 10 kPa, stop for 1 minute, and gradually pressurize to 350-450 kPa; S33. After maintaining the pressure for 72 hours, observe the pressure drop; if the pressure drop is ≤10kPa, it is judged that the overall sealing performance meets the set requirements and the quality is qualified; if the pressure drop is greater than 10kPa, it is judged that the overall sealing performance does not meet the set requirements and the quality is unqualified.

8. A method for removing argon after argon arc welding of an electrical penetration barrel (1) according to claim 1, characterized in that: In the step S5, the specific steps of argon vacuum extraction are as follows: S51, evacuate the electrical penetration member cylinder (1) and the frame (2) where the electromagnetic coil (3) is located to 15-20 kPa by using a vacuum pump, and then inject high-temperature carbon dioxide gas therein to 101 kPa; after maintaining the pressure for 24 hours, evacuate to 8-12 Pa, and repeat this process for at least 3 times; S52. Use an argon detector to detect the gas extracted for the last time to determine whether the argon content in the gas is higher than the set value. If not, inject high-temperature carbon dioxide gas to 101kPa and then evacuate to 1Pa. If higher than the set value, repeat step S51 until the argon content in the extracted gas is no higher than the set value.

9. A method for removing argon after argon arc welding of an electrical penetration barrel (1) according to claim 1, characterized in that: In the step S5, the temperature of the carbon dioxide gas is 150-170°C.

10. A method for removing argon after argon arc welding of an electrical penetration barrel (1) according to claim 8, characterized in that: In the steps S51 and S52, the vacuuming method is intermittent vacuuming, that is, vacuuming 5 kPa and stopping for 2 minutes until the vacuuming reaches the set value.

Images