A test platform and test method for sealing leakage of SF6 insulation equipment by molten bismuth alloy

Abstract

The application discloses a kind of SF6 insulation equipment leakage molten bismuth alloy plugging test platform and test method, belong to high-voltage electrical equipment test technical field.Platform includes 6061-T6 aluminum alloy main body tank, integrated replaceable leakage defect simulation flange piece, temperature control platform, vibration motor, gas interface panel, with main control, intelligent test algorithm and data management module.Can simulate sand eye, weld cracking and other defects, realize-20°C~80°C temperature control, 10~100Hz vibration and 0~0.4MPa pressure Multi-stress coupling experiment.Test method passes through preparation, defect simulation, parameter setting, plugging implementation, data acquisition analysis, scheme verification and life evaluation seven steps, based on machine learning parameter mapping model is established, solves optimal plugging scheme and deduces more than 30 years of service life.Platform has controllability strong, reproducibility high, scalability good and the like Advantages, for GIS leak stoppage technology research provides reliable foundation.

Description

Technical Field

[0001] This invention relates to the field of high-voltage electrical equipment testing technology, and in particular to a test platform and test method for sealing leaks in SF6 insulation equipment with molten bismuth alloy. Background Technology

[0002] Gas-insulated metal-enclosed switchgear (GIS) is widely used in high-voltage and ultra-high-voltage substations due to its compact structure and high reliability. Sulfur hexafluoride (SF6) is the primary insulating and arc-quenching medium in GIS, and its sealing performance directly affects equipment safety. However, GIS equipment is prone to leakage during long-term operation due to manufacturing defects, improper installation, or environmental stress. Common leakage types include flange seal failure, shell pinholes, and weld cracking. SF6 leakage can cause serious problems: First, leakage leads to a decrease in gas density and pressure inside the tank, weakening insulation strength and increasing the risk of partial discharge or insulation breakdown, potentially causing power grid failures; second, continuous leakage requires frequent gas replenishment, increasing operation and maintenance costs; finally, SF6 is a strong greenhouse gas with an extremely high global warming potential (GWP), and even a small leak can exacerbate climate change, violating sustainable development goals.

[0003] Existing technologies for testing GIS leaks are relatively limited, often only simulating single stress conditions, such as controlling only pressure or temperature, lacking the ability to simulate multi-stress coupling. For example, some testing platforms use simple sealed tanks for pressure testing, but cannot simulate the temperature cycles and mechanical vibrations of real operation; other solutions use external heaters or chillers for temperature control, but these are slow to respond, have low accuracy, and are difficult to integrate with vibration. Furthermore, existing platforms suffer from fixed simulation limitations, unable to quickly switch between different types of leak points, restricting a comprehensive evaluation of leak-sealing technologies. Bismuth alloy fusion leak-sealing technology, as an emerging method, can form a sealing layer at the leak point, but its performance is affected by multiple factors such as temperature and vibration. Existing testing platforms cannot provide a reliable verification environment, resulting in a lack of data support for optimizing the leak-sealing process.

[0004] Therefore, there is an urgent need in this field for a highly integrated and controllable testing platform that can simulate the multi-stress coupling conditions of real GIS operating conditions, and realize flexible simulation of leakage defects and accurate evaluation of leak sealing technology. Summary of the Invention

[0005] To address the limitations of existing SF6 insulation equipment leakage testing platforms, which can only simulate single stresses, have fixed defect simulations, and offer low precision in temperature and vibration control, thus failing to support a comprehensive evaluation of bismuth alloy plugging technology, this invention aims to provide an integrated, high-precision testing platform and method. By simulating multi-stress coupling environments and various leakage defects under real-world operating conditions, key data on plugging performance are obtained, plugging process parameters are optimized, and the service life of the plugging body is accurately assessed. This provides reliable support for the research and application of SF6 insulation equipment leakage plugging technology, ensuring power grid safety and sustainable environmental development.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A test platform for sealing leaks in SF6 insulation equipment with molten bismuth alloy includes: a main tank (1), the main tank (1) having a cavity inside, and a first opening, a second opening and a third opening communicating with the cavity on the main tank (1). The first opening, the second opening and the third opening are respectively located on different surfaces of the main tank (1), and the second opening and the third opening are respectively arranged on opposite sides of the main tank (1). The first opening is covered with a detachable top plate (5). A gas interface panel (6) is integrated on the side of the top plate (5) away from the cavity. A replaceable leak defect simulation flange (4) and a temperature control platform (8) are respectively installed on the side of the main tank (1). A vibration motor (7) is installed on the main tank (1) to generate vibration of the main tank (1) during testing. A gas pressure control system that provides gas pressure to the cavity of the main tank (1) is integrated on the gas interface panel (6). A micro leak defect is pre-made on the leak defect simulation flange (4). The temperature control platform (8) provides a controllable temperature environment inside the main tank (1).

[0007] Furthermore, the top plate (5) and the leakage defect simulation flange (4) are connected to the main tank body (1) by an O-ring seal; the O-ring is made of fluororubber.

[0008] Furthermore, the gas pressure control system is equipped with an inlet valve, an outlet valve or a vacuum valve, and a pressure sensor installed on the gas interface panel (6). External gas sources enter through the inlet valve on the gas interface panel (6) and flow into the internal space of the main tank (1). When depressurizing or venting, the gas in the main tank (1) is discharged through the outlet valve or the vacuum valve. Under vacuum conditions, the gas in the main tank (1) is extracted by the outlet valve or the vacuum valve to achieve a negative pressure environment. The pressure sensor collects the pressure signal inside the tank in real time and works in conjunction with the inlet valve, outlet valve or vacuum valve to form a closed-loop gas pressure control circuit, completing the gas flow and pressure regulation of the entire process of filling, stabilizing, venting and vacuuming.

[0009] Furthermore, the micro-leaking defects prefabricated in the leakage defect simulation flange include: sand holes and weld cracks; sand holes are capillary pores with a diameter of 0.1~1mm, and weld cracks are slits processed by wire cutting process on the leakage defect simulation flange.

[0010] Furthermore, the present invention also includes simulating flange seal failure by simulating O-ring groove failure between flange plate (4) and main tank body (1) through leakage defect simulation. O-ring groove failure refers to artificially created scratches or the use of aged O-ring grooves.

[0011] Furthermore, the temperature control platform (8) includes a thermoelectric cooler (TEC), a water-cooled heat dissipation system, an auxiliary heater, a thermal interface material, a temperature sensor, and a PID controller. The cold end of the TEC contacts the tank wall of the main tank (1) through the thermal interface material, and the hot end of the TEC is connected to the water-cooled plate through the thermal interface material. The water-cooled plate, together with the radiator, water pump, and coolant, forms a closed-loop water-cooled heat dissipation system. The auxiliary heater uses a silicone rubber heating sheet or an etched foil heating film, which is attached and fixed to the outer wall of the main tank (1). The temperature sensor is installed on the main tank (1). The TEC, the closed-loop water-cooled heat dissipation system, the auxiliary heater, and the temperature sensor are all connected to the PID controller for control.

[0012] Furthermore, an eccentric block is fixedly installed on the output shaft of the vibration motor (7). The amplitude is changed by adjusting the eccentric block, and the vibration motor (7) is rigidly installed on the main tank (1).

[0013] Furthermore, it also includes a main control system, which connects with the gas pressure control system on the temperature control platform (8), vibration motor (7) and gas interface panel (6) to coordinate and control the gas pressure control system on the temperature control platform (8), vibration motor (7) and gas interface panel (6), supports multi-stress coupling experiments of temperature, pressure and vibration, and realizes multi-parameter linkage control.

[0014] A method for sealing SF6 insulation equipment with molten bismuth alloy leakage is implemented using the aforementioned SF6 insulation equipment molten bismuth alloy sealing test platform, comprising: Vacuuming: Vacuuming is performed by venting or using a vacuum valve to remove the air from the cavity of the main tank (1); Leakage defect simulation: Select the corresponding type of leakage defect simulation flange (4), the flange is prefabricated with sand holes, weld cracks or flange seal failure defects; Sealing test implementation: The temperature control platform (8) controls the temperature of the main tank (1) to the target temperature; the vibration motor (7) sets the vibration frequency and amplitude; SF6 gas is injected into the main tank (1) through the gas pressure control system on the gas interface panel (6) and the target pressure is set; the temperature control platform (8), vibration motor (7) and gas pressure control system are started to maintain the stability of the set working parameters; Molten bismuth alloy sealing material was applied to the defect of the simulated flange (4). The leaked gas was collected by real-time monitoring of the pressure change inside the tank, and the sealing time and real-time leakage rate were recorded.

[0015] Furthermore, the method also includes: Data Acquisition and Analysis: The data management module collects operating parameters, plugging performance indicators, and failure mode information, and transmits the dataset to the intelligent testing algorithm module. Based on experimental design and machine learning principles, the intelligent testing algorithm module uses response surface methodology or genetic algorithms to fit and analyze the data, and establishes a parameter mapping model between input variables and plugging performance indicators. Optimal solution verification: The optimal combination of parameters that achieves the best blocking performance is obtained by solving the parameter mapping model. 3 to 5 sets of verification experiments are repeated under the same test conditions to ensure the reproducibility of the blocking effect. Service life assessment: Based on the Arrhenius model, the operating temperature is increased to 70°C~100°C, and accelerated aging experiments are conducted in combination with vibration and electric field. The service life of the sealing body of more than 30 years is deduced by using a correlation database.

[0016] Furthermore, the motor (7) is set to a vibration frequency of 10~100Hz and an amplitude of 0.1mm~2mm; SF6 gas is filled into the main tank (1) and a target pressure of 0~0.4MPa is set.

[0017] This SF6 insulation equipment leakage molten bismuth alloy plugging test platform uses the main tank as the core test chamber. Through modular integration of key operating condition simulation units such as pressure, leakage defects, vibration, and temperature, it reproduces the leakage scenarios and operating environment of SF6 insulation equipment in actual service, providing a standardized and controllable simulation test environment for the testing and verification of molten bismuth alloy plugging technology.

[0018] The main tank has a hollow structure and serves as the core space for SF6 gas containment and plugging testing. Its detachable top plate facilitates operation, debugging, and test piece arrangement inside the chamber. The gas interface panel on the top plate integrates a gas pressure control system, which can accurately fill the tank with gas and regulate the gas pressure to simulate the internal gas pressure conditions in the actual operation of SF6 insulation equipment. The replaceable leak defect simulation flange on the side of the tank is prefabricated with micro-leak defects, which directly simulates the actual leakage location and leakage state of SF6 insulation equipment, providing a real test object for molten bismuth alloy sealing; The vibration motor, temperature control platform and gas pressure control system integrated on the side of the tank work together to provide vibration and temperature control support for the test environment, and reproduce the vibration, ambient temperature and other operating conditions that SF6 insulation equipment is subjected to in actual operation. Through the independent control and coordinated operation of each functional module, a test environment that closely matches the actual leakage scenario of SF6 insulation equipment is constructed. On this basis, the sealing operation of micro-leakage defects by molten bismuth alloy can be carried out, and the sealing effect can be verified.

[0019] Beneficial effects of this invention: This invention, through its modular, integrated, and replaceable structural design and operational condition simulation design, combines multiple advantages such as structural rationality, realistic operational condition simulation, testing flexibility, and operational practicality. Specific effects are as follows: The main tank adopts a cavity foundation design, and the detachable top plate structure facilitates internal testing operations, equipment layout, and subsequent cleaning. Functional units such as gas interface panels, leakage defect simulation flanges, vibration motors, and temperature control platforms are all modularly integrated on the outside of the tank, with a clear layout and no interference between them. The maintenance and replacement of individual modules do not require disassembling the entire equipment, resulting in high maintenance efficiency.

[0020] Using a prefabricated miniature leak defect-simulated flange as a leak test carrier, SF6 gas in the main tank leaks from the miniature leak defect, directly matching the actual leak characteristics of SF6 insulation equipment. At the same time, it is equipped with a gas pressure control system, vibration motor, and temperature control heating device, which can reproduce the key operating conditions such as gas pressure, vibration, and temperature of SF6 equipment, realize multi-parameter collaborative scenario simulation, and make the environment of molten bismuth alloy plugging test highly consistent with the actual service environment, so that the test results are more realistic and have more engineering reference value.

[0021] The leakage defect simulation flange is a replaceable design, allowing for the replacement of prefabricated flanges of different specifications and types of leakage defects according to testing needs, simulating various leakage conditions of SF6 insulation equipment; operating parameters such as gas pressure, vibration, and temperature can be independently adjusted, supporting single-parameter or multi-parameter linkage testing modes, and enabling multi-dimensional testing of the sealing effect and sealing stability of molten bismuth alloy under different operating conditions, adapting to the entire process of research, optimization, and verification of molten bismuth alloy sealing technology.

[0022] The gas pressure control system is integrated into the gas interface panel on the top plate, and the heating function is integrated into the temperature control platform on the side of the tank. The core operating condition control units are all integrated nearby, eliminating the need for additional complex external equipment. The overall integration of the equipment is high and the operation process is simplified. At the same time, all functional modules act directly on the main tank, making the transmission of operating condition parameters more direct and the control response more sensitive, thereby improving the convenience and efficiency of testing operations.

[0023] A dedicated standardized testing platform was designed for molten bismuth alloy plugging technology for SF6 insulation equipment leakage. This platform addresses the lack of professional simulation testing equipment for this type of plugging technology and provides a dedicated test carrier for optimizing the formulation of molten bismuth alloy plugging materials, improving the plugging process, and standardizing the verification of plugging effects. This can effectively promote the research and development and engineering application of molten bismuth alloy plugging technology for SF6 insulation equipment leakage. Attached Figure Description

[0024] Figure 1 This is a perspective view of a test platform for sealing leaks in SF6 insulation equipment using molten bismuth alloy, as proposed in this invention.

[0025] Figure 2 This is a side view of a test platform for sealing leaks in SF6 insulation equipment using molten bismuth alloy, as proposed in this invention.

[0026] Figure 3 This is a flowchart of a test method for sealing leaks in SF6 insulation equipment with molten bismuth alloy, as proposed in this invention.

[0027] Legend: 1. Main tank body; 2. O-ring groove; 3. O-ring; 4. Leakage defect simulation flange; 5. Top plate; 6. Gas interface panel; 7. Vibration motor; 8. Temperature control platform. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1 A test platform for sealing leaks in SF6 insulation equipment with molten bismuth alloy includes: a main tank 1, the main tank 1 having a cavity inside, and the main tank 1 having a first opening, a second opening and a third opening communicating with the cavity. The first opening, the second opening and the third opening are located on different surfaces of the main tank 1, and the second opening and the third opening are respectively located on opposite sides of the main tank 1. The first opening is covered by a removable top plate 5. A gas interface panel 6 is integrated on the side of the top plate 5 facing away from the cavity. Replaceable leakage defect simulation flanges 4 and temperature control platforms 8 are respectively installed on the opposite sides of the main tank 1. A vibration motor 7 is installed on the main tank 1 to generate vibration during testing. The gas interface panel 6 integrates a gas pressure control system that supplies gas pressure to the cavity of the main tank 1. Miniature leakage defects are pre-fabricated on the leakage defect simulation flanges 4. The temperature control platform 8 provides a controllable temperature environment inside the main tank 1. The vibration motor 7 is rigidly mounted to the tank wall using M4 hexagonal screws to ensure effective transmission of vibration energy.

[0030] In one embodiment of the present invention, the main tank 1 adopts a cuboid structure, is made of 6061-T6 aluminum alloy, and has an internal cylindrical cavity; the tank dimensions are 400mm × 350mm × 350mm, and the internal cylindrical cavity has a diameter of 320mm and a depth of 330mm; simulating a GIS cylindrical structure. The top plate 5 and the leakage defect simulation flange 4 are sealed to the main tank 1 through an O-ring 3 in the O-ring groove 2; the O-ring groove 2 and the O-ring 3 are made of fluororubber.

[0031] In one embodiment of the present invention, the gas pressure control system includes an inlet valve, an outlet valve or a vacuum valve, and a pressure sensor installed on the gas interface panel 6. External gas enters through the inlet valve on the gas interface panel 6 and flows into the internal space of the main tank 1. During depressurization or venting, the gas inside the main tank 1 is discharged through the outlet valve or vacuum valve. Under vacuum conditions, the outlet valve or vacuum valve extracts the gas from the main tank 1 to achieve a negative pressure environment. The pressure sensor collects the internal pressure signal in real time and works in conjunction with the inlet valve, outlet valve, or vacuum valve to form a closed-loop gas pressure control circuit, completing the entire process of gas flow and pressure regulation during filling, stabilizing, venting, and vacuuming, supporting internal gas pressure control up to 4 atmospheres. The vacuum valve is used to remove air before the experiment to ensure SF6 purity. The sealing test uses helium mass spectrometry leak detection to verify that the leakage rate of the tank and each interface at 4 atmospheres is less than 1×10⁻⁶ Pa·m. 3 / s.

[0032] In one embodiment of the present invention, the leakage defect simulation flange 4 is made of aluminum alloy or stainless steel, supporting quick disassembly and replacement. A micro-leakage defect is pre-fabricated in the center: pinholes are simulated using capillary pores with a diameter of 0.1~1mm, and weld cracking is simulated using a narrow slit processed by wire cutting.

[0033] In one embodiment of the present invention, the flange sealing failure is simulated by simulating the failure of the O-ring grooves 2 and 3 between the flange plate 4 and the main tank 1 through leakage defects. The failure of the O-ring grooves 2 and 3 refers to the artificial creation of scratches in the O-ring groove 2 or the use of aged O-rings 3.

[0034] In one embodiment of the present invention, the temperature control platform 8 includes a thermoelectric cooler (TEC), a water-cooled heat dissipation system, an auxiliary heater, a thermal interface material, a temperature sensor, and a PID controller. The cold end of the TEC contacts the tank wall of the main tank 1 through the thermal interface material, and the hot end of the TEC is connected to the water-cooled plate through the thermal interface material. The water-cooled plate, together with the radiator, water pump, and coolant, forms a closed-loop water-cooled heat dissipation system. The auxiliary heater uses a silicone rubber heating sheet or an etched foil heating film, which is attached and fixed to the outer wall of the main tank 1. The temperature sensor is installed on the main tank 1. The TEC, the closed-loop water-cooled heat dissipation system, the auxiliary heater, and the temperature sensor are all connected to the PID controller for control.

[0035] In one embodiment of the present invention, the vibration motor 7 is a 12V DC motor with a maximum speed of 8000 rpm. An eccentric block can also be installed on the output shaft of the vibration motor 7. The amplitude can be changed by adjusting the eccentric block. It is rigidly installed on the side of the main tank 1 by M4 screws. Vibration control is achieved through a DC speed controller, integrated into the main control system (such as a PLC or industrial PC), which supports programmable control of vibration frequency and duration.

[0036] In one embodiment of the present invention, the test platform of the present invention further includes a main control system, which is connected to the temperature control platform 8, the vibration motor 7 and the gas pressure control system on the gas interface panel 6 by means of control signals, coordinates and controls the temperature control platform 8, the vibration motor 7 and the gas pressure control system on the gas interface panel 6, supports multi-stress coupling experiments of temperature, pressure and vibration, and realizes multi-parameter linkage control.

[0037] In one embodiment of the present invention, after platform integration, comprehensive debugging is performed, and multi-stress coupling experiments are conducted: for example, a high temperature of 70°C is set and vibration is applied to simulate the summer operating conditions of GIS; or vibration is applied at a low temperature of 0°C to simulate a cold environment. During the experiment, a bismuth alloy plugging device is installed at the leak point, and the leakage rate is measured by the pressure drop method (monitoring pressure changes over time) or the wrapping method (collecting leaked gas) to evaluate the plugging effect.

[0038] Parameter settings: Input variables include bismuth alloy element composition, melting temperature, ambient temperature, pressure (0-0.4MPa), and vibration frequency (10-100Hz); output variables are sealing performance indicators (leakage rate, sealing time, and shear strength of the seal).

[0039] Experimental Execution: A multi-factor coupled experiment was conducted. For example, the alloy composition was set as 58Bi-42Sn (melting point 139°C). Sand hole defects were sealed at 50°C, 0.3MPa, vibration frequency 50Hz, and electric field 5kV / cm. The leakage rate was measured using the pressure drop method (monitoring pressure changes over time) or the wrapping method (collecting leaked gas). The target leakage rate after sealing was ≤1×10⁻⁶. -5 Pa·m 3 / s, blocking time ≤10 minutes.

[0040] Data acquisition: Operating parameters and sealing performance are recorded in real time through sensors to form a structured dataset.

[0041] Optimization analysis: Response surface methodology (RSM) or genetic algorithms are used to establish a mapping model between parameters and performance, and to solve for the optimal parameter combination (such as the alloy composition and temperature that minimizes leakage rate). For example, regression analysis is used to verify the effect of In on melting point reduction.

[0042] Verification experiment: Repeat the optimal parameter experiment to ensure the reliability and reproducibility of the blocking.

[0043] Simultaneously, a database linking "operating condition parameters - sealing performance - failure modes" was established. This database, built using an SQL system, stores data from each experiment, including operating condition parameters such as alloy element ratios, temperature, pressure, vibration frequency, and electric field strength, as well as performance indicators such as leakage rate and sealing time. It also records failure modes (e.g., seal creep, cracking, alloy softening). The database supports data mining for: Failure analysis: Identify common failure modes, such as sealing failure caused by softening of bismuth alloys at high temperatures, or interface debonding caused by vibration.

[0044] Solution optimization: Recommend the optimal sealing process through cluster analysis, such as the best injection parameters (driving pressure, pulse width) for flange leakage.

[0045] Lifetime prediction: Integrating machine learning models (such as neural networks) to predict the service life of the sealing body for more than 30 years based on accelerated aging experimental data. Accelerated aging parameter optimization is based on the Arrhenius model, such as cyclic testing at high temperatures of 70°C to 100°C (each cycle of 1000 hours is equivalent to 10 years of natural aging), combined with vibration (frequency 50Hz) and electric field (5kV / cm) to simulate long-term service conditions.

[0046] This invention constructs a reliable and flexible testing platform through the above steps, providing a practical foundation for GIS leak sealing technology research. Specific parameters can be adjusted according to actual needs, but without departing from the core design of this invention.

[0047] Example 2 A method for sealing SF6 insulation equipment leaks with molten bismuth alloy is provided, utilizing the SF6 insulation equipment leakage molten bismuth alloy sealing test platform described in Example 1. The method includes: Vacuuming: The air inside the cavity of the main tank 1 is removed by evacuating the air through the venting or vacuuming valve; Leakage defect simulation: Select the corresponding type of leakage defect to simulate flange plate 4, such as pre-fabricated sand holes, weld cracks, or flange seal failure. Sealing test implementation: The temperature control platform 8 controls the temperature of the main tank 1 to the target temperature with an accuracy of ±0.5°C; the vibration motor 7 is set to a vibration frequency of 10~100Hz and an amplitude of 0.1mm~2mm; SF6 gas is introduced into the main tank 1 through the gas pressure control system on the gas interface panel 6, and the target pressure is set to 0~0.4MPa; the temperature control platform 8, vibration motor 7 and gas pressure control system are started to maintain the stability of the set operating parameters; Molten bismuth alloy sealing material was applied to the defect of the simulated leak flange 4. By monitoring the pressure change inside the tank in real time, the leaked gas was collected, and the sealing time and real-time leakage rate were recorded.

[0048] Data Acquisition and Analysis: The data management module collects operating parameters, plugging performance indicators, and failure mode information, and transmits the dataset to the intelligent testing algorithm module. Based on experimental design and machine learning principles, the intelligent testing algorithm module uses response surface methodology or genetic algorithms to fit and analyze the data, and establishes a parameter mapping model between input variables and plugging performance indicators. Optimal solution verification: The optimal combination of parameters that achieves the best blocking performance is obtained by solving the parameter mapping model. 3 to 5 sets of verification experiments are repeated under the same test conditions to ensure the reproducibility of the blocking effect. Service life assessment: Based on the Arrhenius model, the operating temperature is increased to 70°C~100°C, and accelerated aging experiments are conducted in combination with vibration and electric field. The service life of the sealing body of more than 30 years is deduced by using a correlation database.

[0049] 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 foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A test platform for sealing leaks in SF6 insulation equipment with molten bismuth alloy, characterized in that, include: The main body (1) has a cavity inside. The main body (1) is provided with a first opening, a second opening and a third opening that communicate with the cavity. The first opening, the second opening and the third opening are located on different surfaces of the main body (1). The second opening and the third opening are respectively provided on opposite sides of the main body (1). The first opening is covered with a detachable top plate (5). A gas interface panel (6) is integrated on the side of the top plate (5) away from the cavity. A replaceable leak defect simulation flange (4) and a temperature control platform (8) are respectively installed on the side of the main tank (1). A vibration motor (7) is installed on the main tank (1) to generate vibration of the main tank (1) during testing. A gas pressure control system that provides gas pressure to the cavity of the main tank (1) is integrated on the gas interface panel (6). A micro leak defect is pre-made on the leak defect simulation flange (4). The temperature control platform (8) provides a controllable temperature environment inside the main tank (1).

2. The SF6 insulation equipment leakage molten bismuth alloy sealing test platform according to claim 1, characterized in that: The top plate (5) and the leakage defect simulation flange (4) are connected to the main tank (1) by an O-ring seal; the O-ring is made of fluororubber.

3. The SF6 insulation equipment leakage molten bismuth alloy sealing test platform according to claim 1, characterized in that: The gas pressure control system is equipped with an inlet valve, an outlet valve or a vacuum valve, and a pressure sensor installed on the gas interface panel (6). External gas sources enter through the inlet valve on the gas interface panel (6) and flow into the internal space of the main tank (1). When depressurizing or venting, the gas in the main tank (1) is discharged through the outlet valve or the vacuum valve. Under vacuum conditions, the gas in the main tank (1) is extracted by the outlet valve or the vacuum valve to achieve a negative pressure environment. The pressure sensor collects the pressure signal inside the tank in real time and works in conjunction with the inlet valve, outlet valve or vacuum valve to form a closed-loop gas pressure control circuit to complete the gas flow and pressure regulation of the entire process of filling, stabilizing, venting and vacuuming.

4. The SF6 insulation equipment leakage molten bismuth alloy sealing test platform according to claim 1, characterized in that: The micro-leaking defects prefabricated in the simulated flange include: pinholes and weld cracks; pinholes are capillary pores with a diameter of 0.1~1mm, and weld cracks are slits processed by wire cutting on the simulated flange.

5. The SF6 insulation equipment leakage molten bismuth alloy sealing test platform according to claim 2, characterized in that: It also includes simulating flange seal failure by simulating the failure of the O-ring groove between the flange plate (4) and the main tank body (1) through leakage defects. O-ring groove failure refers to artificially created scratches or the use of aged O-ring grooves.

6. The SF6 insulation equipment leakage molten bismuth alloy sealing test platform according to claim 1, characterized in that: The temperature control platform (8) includes a thermoelectric cooler (TEC), a water-cooled heat dissipation system, an auxiliary heater, a thermal interface material, a temperature sensor, and a PID controller. The cold end of the TEC contacts the tank wall of the main tank (1) through the thermal interface material, and the hot end of the TEC is connected to the water-cooled plate through the thermal interface material. The water-cooled plate, together with the radiator, water pump, and coolant, forms a closed-loop water-cooled heat dissipation system. The auxiliary heater uses a silicone rubber heating sheet or an etched foil heating film, which is attached and fixed to the outer wall of the main tank (1). The temperature sensor is installed on the main tank (1). The TEC, the closed-loop water-cooled heat dissipation system, the auxiliary heater, and the temperature sensor are all connected to the PID controller for control.

7. The SF6 insulation equipment leakage molten bismuth alloy sealing test platform according to claim 1, characterized in that: An eccentric block is fixedly installed on the output shaft of the vibration motor (7). The amplitude is changed by adjusting the eccentric block. The vibration motor (7) is rigidly installed on the main tank (1).

8. The SF6 insulation equipment leakage molten bismuth alloy sealing test platform according to claim 1, characterized in that: It also includes a main control system, which connects with the gas pressure control system on the temperature control platform (8), vibration motor (7) and gas interface panel (6) to coordinate and control the gas pressure control system on the temperature control platform (8), vibration motor (7) and gas interface panel (6), supports multi-stress coupling experiments of temperature, pressure and vibration, and realizes multi-parameter linkage control.

9. A method for testing the sealing of molten bismuth alloy leaks in SF6 insulation equipment, wherein the method is implemented using the SF6 insulation equipment molten bismuth alloy leak sealing test platform as described in any one of claims 1-8, characterized in that: The SF6 insulation equipment leakage molten bismuth alloy sealing test method includes: Vacuuming: Vacuuming is performed by venting or using a vacuum valve to remove the air from the cavity of the main tank (1); Leakage defect simulation: Select the corresponding type of leakage defect simulation flange (4), the flange is prefabricated with sand holes, weld cracks or flange seal failure defects; Sealing test implementation: The temperature control platform (8) controls the temperature of the main tank (1) to the target temperature; the vibration motor (7) sets the vibration frequency and amplitude; SF6 gas is injected into the main tank (1) through the gas pressure control system on the gas interface panel (6) and the target pressure is set; the temperature control platform (8), vibration motor (7) and gas pressure control system are started to maintain the stability of the set working parameters; Molten bismuth alloy sealing material was applied to the defect of the simulated flange (4). The leaked gas was collected by real-time monitoring of the pressure change inside the tank, and the sealing time and real-time leakage rate were recorded.

10. A test method for sealing leaks in SF6 insulating equipment with molten bismuth alloy, characterized in that, The method further includes: Data Acquisition and Analysis: The data management module collects operating parameters, plugging performance indicators, and failure mode information, and transmits the dataset to the intelligent testing algorithm module. Based on experimental design and machine learning principles, the intelligent testing algorithm module uses response surface methodology or genetic algorithms to fit and analyze the data, and establishes a parameter mapping model between input variables and plugging performance indicators. Optimal solution verification: The optimal combination of parameters that achieves the best blocking performance is obtained by solving the parameter mapping model. 3 to 5 sets of verification experiments are repeated under the same test conditions to ensure the reproducibility of the blocking effect. Service life assessment: Based on the Arrhenius model, the operating temperature is increased to 70°C~100°C, and accelerated aging experiments are conducted in combination with vibration and electric field. The service life of the sealing body of more than 30 years is deduced by using a correlation database.

11. The test method for sealing leakage in SF6 insulating equipment with molten bismuth alloy according to claim 9, characterized in that, The motor (7) is set to a vibration frequency of 10~100Hz and an amplitude of 0.1mm~2mm; SF6 gas is filled into the main tank (1) and the target pressure is set to 0~0.4MPa.

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