Device and method for extracting oil from casing pipe in negative pressure state

Abstract

The invention relates to the technical field of transformer maintenance, in particular to a sleeve negative pressure state oil extraction device which comprises an unmanned aerial vehicle, a connector fixedly connected with the unmanned aerial vehicle, an oil extractor connected with the connector and a positioner installed on a transformer sleeve base. The oil extractor comprises a shell, a third needle tube, a fourth needle tube and an oil extraction tube, the third needle tube and the fourth needle tube are mounted in the shell, the oil extraction tube passes through a guide tube and is communicated with the third needle tube and the fourth needle tube, a position control capsule is arranged at the end of the oil extraction tube, and an oil through hole is formed between the position control capsule and the end of the oil extraction tube. The position control capsule is communicated with the first needle tube and the second needle tube through the position control tube. Therefore, the device and the method for extracting oil from the bushing in the negative pressure state are used for solving the technical problem of inconvenience in extracting oil from the bushing of the transformer in the negative pressure state.

Description

Technical Field

[0001] The present application relates to the technical field of transformer maintenance, and more specifically, to a device and method for extracting oil from a bushing under negative pressure. Background Art

[0002] In the power system, the transformer bushing is an important part of the transformer, and its operating status directly affects the safety and stability of the entire power grid. In order to monitor the insulation status of the bushing, regular oil chromatography analysis is an indispensable and important link. However, in actual operation, the pressure state of the sealing air at the top of the transformer bushing directly affects the smooth progress of the oil extraction work. When the pressure of the sealing air at the top of the bushing is greater than the atmospheric pressure, the oil extraction work is relatively simple. You only need to connect the oil extraction tool to the oil extraction port, and the casing oil can flow out smoothly. However, when the pressure of the sealing air at the top of the bushing is less than the atmospheric pressure (that is, negative pressure is formed inside the bushing), the existing oil extraction tool cannot directly use the negative pressure difference to extract oil, resulting in obstruction of the oil extraction work.

[0003] Problems with the existing technology Risks and costs of aerial work: For transformer bushings with voltage levels of 110kV and above, the vent holes are usually located at the top of the bushing, which is at a relatively high position. When negative pressure is formed inside the bushing, it is necessary to open the vent bolt to break the negative pressure. This operation often requires the cooperation of an aerial work vehicle, which not only increases the operating cost, but also significantly increases the operating risk. Air purity and humidity issues: When the vent hole of the bushing is opened to break the negative pressure, external air will directly enter the inside of the bushing. Since the on-site conditions make it difficult to meet the strict requirements for humidity and purity of the air inside the bushing, this may lead to a decrease in the insulation performance of the bushing, thereby affecting its safe and stable operation. Low oil extraction efficiency: When facing negative pressure inside the bushing, the existing oil extraction method requires an additional venting step, which not only increases the complexity of the operation, but also prolongs the oil extraction time and reduces work efficiency. Therefore, a new type of device for extracting oil under negative pressure is needed. Summary of the invention

[0004] Based on the above problems, the present application proposes a device and method for extracting oil from a bushing under negative pressure, which is used to solve the technical problem of the inconvenience of extracting oil from a transformer under negative pressure.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A device for extracting oil from a bushing under negative pressure, comprising a drone, a connector fixedly connected to the drone, an oil extractor connected to the connector, and a positioner installed on a transformer bushing base;

[0007] The oil extractor includes an outer shell, a third needle tube and a fourth needle tube installed in the outer shell, and an oil extraction pipe connected to the third needle tube and the fourth needle tube through a conduit, a position control capsule is arranged at the end of the oil extraction pipe, an oil through hole is arranged between the position control capsule and the end of the oil extraction pipe, and the position control capsule is connected to the first needle tube and the second needle tube through the position control pipe.

[0008] In a specific feasible implementation scheme, the third needle tube and the fourth needle tube are connected by a catheter, the position control tube is located inside the oil extraction pipe, and automatic valves are provided at the connection points between the third needle tube and the fourth needle tube and the catheter, and at the connection points between the first needle tube and the second needle tube and the position control tube.

[0009] In a specific possible implementation scheme, the connector includes a fixing seat connected to the drone base, a first motor is installed on the fixing seat, a turntable is installed on the transmission shaft of the first motor, and a spiral groove is provided on the turntable;

[0010] Four slide grooves are arranged on the fixed seat, and each of the slide grooves is provided with a clamping claw. The middle part of each clamping claw is slidably connected with each of the slide grooves respectively, and a slider matched with the spiral groove is fixedly arranged on the upper end of each clamping claw, and each of the sliders is slidably connected with the spiral groove.

[0011] In a specific possible implementation manner, the housing is provided with a clamping block for easy clamping by the clamping claws, the surface of the clamping block is provided with ridges for increasing the roughness, and the lower end of the clamping claw is provided with a rubber gasket.

[0012] In a specific feasible implementation scheme, the positioner includes a base plate, on which a left baffle and a right baffle are mounted, one end of the left baffle and the right baffle are fixedly mounted on the base plate, a gap is provided between the base plate and the left baffle and the right baffle, and a longitudinal positioning structure is provided on the base plate.

[0013] In a specific possible implementation scheme, the bottom plate is provided with an opening matched with the oil extraction port of the transformer bushing.

[0014] In a specific feasible implementation scheme, a steering plate is provided on the opening, and the steering plate is rotatably connected to the base plate. Two guide rails are provided on the base plate, and the two guide rails are respectively located on both sides of the base plate. A moving block is provided on each guide rail, and the moving block is rotatably connected to the guide rail. Each moving block is provided with a connecting rod connected to the rotating plate.

[0015] In a specific possible implementation manner, one end of each of the connecting rods is hinged to the steering plate, and the other end of each of the connecting rods is hinged to the moving block.

[0016] In a specific possible implementation scheme, one of the moving blocks is connected to an electric push rod via a pull rod, the electric push rod is fixedly connected to the base plate, and each of the moving blocks is installed with a baffle for limiting the oil pipe.

[0017] In a specific implementation scheme, the method of use is as follows:

[0018] Here’s how to use it:

[0019] S1. Preparation:

[0020] Ensure that the drone, connector, oil extractor, and locator mounted on the transformer bushing base are in good working condition;

[0021] Check whether the connections between the first needle tube, the second needle tube, the third needle tube, the fourth needle tube, the position control tube, the oil extraction tube and the position control capsule are tight, and ensure that all automatic valves are in the closed state;

[0022] Make sure the locator is correctly installed on the transformer bushing base and adjust its position to ensure alignment with the oil tapping port;

[0023] S2. Drone takeoff and positioning:

[0024] Operate the drone to take off and fly to the transformer area where the locator is installed;

[0025] Connector and oil extractor connection:

[0026] The UAV starts to connect with the oil extractor through its fixedly connected connector. Specifically, the clamping claw on the connector is driven by the first motor and gradually opens and clamps the clamping block on the oil extractor housing through the interaction of the spiral groove and the slide groove.

[0027] S3. Adjust the oil extractor position:

[0028] The UAV adjusts its flight attitude and position to align the oil extraction pipe on the oil extractor with the oil extraction port on the transformer bushing;

[0029] S4, start to extract oil:

[0030] The first needle tube is filled with air, and the second needle tube is filled with insulating oil. When the position-controlled capsule needs to float upward, the automatic valve on the second needle tube is opened, and the automatic valve on the first needle tube is closed. The first needle tube draws the insulating oil in the position-controlled capsule back to the second needle tube, and then the automatic valve on the second needle tube is closed, and the automatic valve on the first needle tube is opened, and the first needle tube injects air into the position-controlled tube and the position-controlled capsule. When the position-controlled capsule needs to sink, the automatic valve on the first needle tube is opened, and the automatic valve on the second needle tube is closed. The first needle tube draws the air in the position-controlled capsule back to the first needle tube, and then the automatic valve on the first needle tube is opened, and the automatic valve on the second needle tube is opened, and the second needle tube injects insulating oil into the position-controlled tube and the position-controlled capsule;

[0031] The method of injecting oil into the casing is that the third needle tube is responsible for extracting oil from the casing and the fourth needle tube is responsible for injecting oil into the casing;

[0032] Initial state:

[0033] The position control pipe, oil extraction pipe and all pipelines are filled with insulating oil to ensure that no air is introduced into the casing when the pipeline is inserted into the casing;

[0034] The fourth needle tube is filled with low-temperature qualified insulating oil (low-temperature insulating oil ensures that the insulating oil accumulates at the bottom of the bushing after being injected into the bushing and does not move upward), the third needle tube is empty, and the automatic valves on the third and fourth needle tubes are closed;

[0035] Insert the oil extraction pipe and the position control pipe into the casing along the oil extraction port; while controlling the position control capsule to sink;

[0036] Open the automatic valve on the fourth needle tube, control the fourth needle tube to inject low-temperature insulating oil into the bushing. At this time, the newly injected insulating oil has a low temperature and will gather at the bottom of the bushing, and will not move upward until the pressure in the bushing increases and the negative pressure eliminates the automatic valve on the fourth needle tube, and controls the position-controlled capsule to float up. After floating up, the position of the oil hole changes to ensure that the taken insulating oil is not contaminated by the injected insulating oil;

[0037] At this time, the casing is under positive pressure, the automatic valve on the third needle tube is opened, and the insulating oil fills the casing and flows into the third needle tube along the oil extraction pipe;

[0038] Take 20mL of insulating oil, then close the automatic valve on the third needle tube, remove the third needle tube, use the 20mL of insulating oil as waste oil for cleaning the pipelines and automatic valves, drain it into the waste oil barrel, connect the third needle tube, open the automatic valve on the third needle tube to let the insulating oil flow into the third needle tube to complete the oil extraction work, and then close the automatic valve on the third needle tube;

[0039] S5, finish oil extraction and return;

[0040] S6. Subsequent processing:

[0041] Clean and maintain the oil extractor, drone and its connected parts in preparation for the next use.

[0042] Positive effects of the present invention:

[0043] The device integrates multiple components such as drones, connectors, oil extractors and locators, realizing full automated operations from takeoff, positioning, connection to oil extraction, greatly improving work efficiency and safety.

[0044] The design of the locator ensures that the oil extractor can be accurately aligned with the oil extraction port of the transformer bushing, while the clamping claws and rubber gaskets on the connector ensure stable clamping of the oil extractor, preventing it from falling off or loosening during the oil extraction process.

[0045] By alternately injecting and extracting air and insulating oil in the first needle tube and the second needle tube, precise control of the position-controlled capsule is achieved, so that it can float up or sink as needed, thereby ensuring the smooth progress of the oil extraction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0047] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of the structure of a drone and a connector according to an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of the structure of a positioner according to an embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of the structure of an oil extractor according to an embodiment of the present invention;

[0051] Figure 5 This is a schematic diagram of the structure of the floating position-controlled capsule according to an embodiment of the present invention;

[0052] Figure 6 This is a schematic diagram of the structure of the position-controlled capsule sinking according to an embodiment of the present invention;

[0053] Figure 7 This is a schematic diagram of the structure of a connector according to an embodiment of the present invention;

[0054] Figure 8 It is a schematic structural diagram of another angle of the connector according to an embodiment of the present invention;

[0055] Description of Reference Numerals

[0056] 1. UAV; 2. Shell; 3. First needle tube; 4. Second needle tube; 5. Third needle tube; 6. Fourth needle tube; 7. Oil extraction pipe; 8. Position control capsule; 9. Catheter; 10. Automatic valve; 11. Position control tube; 12. Fixed seat; 13. First motor; 14. Turntable; 15. Spiral groove; 16. Slide groove; 17. Clamp; 18. Slider; 19. Clamp block; 20. Bottom plate; 21. Left baffle; 22. Right baffle; 23. Opening; 24. Steering plate; 25. Guide rail; 26. Moving block; 27. Connecting rod; 28. Electric push rod; 29. ​​Pull rod; 30. Baffle; 31. Oil through hole. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0058] Example 1

[0059] like Figure 1 and Figure 4-6 As shown, a device for extracting oil from a bushing under negative pressure includes a drone 1, a connector fixedly connected to the drone 1, an oil extractor connected to the connector, and a positioner installed on a transformer bushing base.

[0060] The oil extractor includes a housing 2, a third needle tube 5 and a fourth needle tube 6 installed in the housing 2, and an oil extraction pipe 7 connected to the third needle tube 5 and the fourth needle tube 6 through a conduit 9. A position control capsule 8 is provided at the end of the oil extraction pipe 7. An oil through hole 31 is provided between the position control capsule 8 and the end of the oil extraction pipe 7. The position control capsule 8 is connected to the first needle tube 3 and the second needle tube 4 through a position control tube 11. The position control capsule 8 is used to control the position of the oil through hole 31. When the position control capsule 8 is filled with air, the density of the position control capsule 8 is less than that of the insulating oil, and the position control capsule 8 floats upward in the insulating oil; when the position control capsule 8 is filled with insulating oil, the position control capsule 8 is filled with insulating oil, and the outer wall of the position control capsule 8 is made of silicone material with a density greater than that of the insulating oil, so the overall density is greater than that of the insulating oil, and the position control capsule 8 sinks downward in the insulating oil.

[0061] The third needle tube 5 and the fourth needle tube 6 are connected through a conduit 9, the position control tube 11 is located inside the oil extraction pipe 7, and automatic valves 10 are provided at the connection points between the third needle tube 5 and the fourth needle tube 6 and the conduit 9, and at the connection points between the first needle tube 3 and the second needle tube 4 and the position control tube 11.

[0062] The drone 1 can replace manual labor in operations at high altitudes, dangerous areas or areas that are difficult to reach, such as extracting oil from high-altitude equipment such as oil derricks and transformers, thereby significantly reducing the risks faced by operators.

[0063] The negative pressure oil extraction technology injects oil into the inside of the bushing to eliminate the negative pressure, allowing the insulating oil to flow into the oil extraction pipe 7, thereby improving the efficiency and speed of oil extraction.

[0064] The device closely combines the drone 1, connector, oil extractor and locator to form an efficient and convenient oil extraction system. This integrated design not only simplifies the operation process, but also improves the stability and reliability of the system.

[0065] Example 2

[0066] like Figure 1 , 7 As shown in Figure 8, the difference between this embodiment and the above embodiment is that the connector is described in more detail. A device for extracting oil from a bushing in a negative pressure state includes a drone 1, a connector fixedly connected to the drone 1, an oil extractor connected to the connector, and a positioner installed on the base of the transformer bushing.

[0067] The oil extractor includes an outer shell 2, a third needle tube 5 and a fourth needle tube 6 installed in the outer shell 2, and an oil extraction pipe 7 connected to the third needle tube 5 and the fourth needle tube 6 through a conduit 9, a position control capsule 8 is provided at the end of the oil extraction pipe 7, an oil through hole 31 is provided between the position control capsule 8 and the end of the oil extraction pipe 7, and the position control capsule 8 is connected to the first needle tube 3 and the second needle tube 4 through a position control tube 11.

[0068] The connector includes a fixing seat 12 connected to the base of the drone 1 , a first motor 13 is installed on the fixing seat 12 , a turntable 14 is installed on the transmission shaft of the first motor 13 , and a spiral groove 15 is provided on the turntable 14 .

[0069] The fixed seat 12 is provided with four slide grooves 16, each of which is provided with a clamping jaw 17, the middle part of each clamping jaw 17 is slidably connected with each of the slide grooves 16, and the upper end of each clamping jaw 17 is fixedly provided with a slider 18 adapted to the spiral groove 15, and each of the sliders 18 is slidably connected with the spiral groove 15.

[0070] The connector is connected to the base of the drone 1 through the fixing seat 12 , and the turntable 14 is driven to rotate by the first motor 13 , and then the spiral groove on the turntable 14 cooperates with the slider 18 on the clamp 17 to realize the automatic opening and closing of the clamp 17 .

[0071] Through the drive of the motor and the cooperation between the spiral groove 15 and the slider 18, the connector can realize the function of automatically clamping and releasing the oil extractor without manual intervention, thereby improving the working efficiency and safety.

[0072] How the connector works:

[0073] Before the UAV 1 is ready to take off, the connector is in an initial state, and the clamping claw 17 is in an open state in the slide slot 16, ready to receive the oil extractor.

[0074] When the drone 1 reaches the designated position and is ready to connect to the oil extractor, the first motor 13 is started to drive the turntable 14 to rotate. The spiral groove 15 on the turntable 14 cooperates with the slider 18 on the clamping jaw 17, so that the slider 18 moves along the spiral groove 15 and drives the clamping jaw 17 to move toward the center, so that the clamping jaw 17 clamps the oil extractor.

[0075] After the operation is completed or the oil extractor needs to be replaced, the first motor 13 rotates in the reverse direction, driving the rotary disk 14 to rotate in the reverse direction. The cooperation between the spiral groove 15 and the slider 18 causes the clamping jaw 17 to gradually open and release the oil extractor.

[0076] Example 3

[0077] like Figure 3 As shown, the difference between this embodiment and the above embodiment is that the positioner is described in detail, a device for extracting oil from a bushing under negative pressure, including a drone 1, a connector fixedly connected to the drone 1, an oil extractor connected to the connector, and a positioner installed on the base of the transformer bushing.

[0078] The oil extractor includes an outer shell 2, a third needle tube 5 and a fourth needle tube 6 installed in the outer shell 2, and an oil extraction pipe 7 connected to the third needle tube 5 and the fourth needle tube 6 through a conduit 9, a position control capsule 8 is provided at the end of the oil extraction pipe 7, an oil through hole 31 is provided between the position control capsule 8 and the end of the oil extraction pipe 7, and the position control capsule 8 is connected to the first needle tube 3 and the second needle tube 4 through a position control tube 11.

[0079] The housing 2 is provided with a clamping block 19 for convenient clamping by the clamping claw 17 . The surface of the clamping block 19 is provided with ridges for increasing the roughness. The lower end of the clamping claw 17 is provided with a rubber gasket.

[0080] The positioner includes a base plate 20, on which a left baffle 21 and a right baffle 22 are installed. One end of the left baffle 21 and the right baffle 22 are fixedly installed on the base plate 20, a gap is provided between the base plate 20 and the left baffle 21 and the right baffle 22, and a longitudinal positioning structure is provided on the base plate 20.

[0081] The bottom plate 20 is provided with an opening 23 which matches the oil inlet of the transformer bushing.

[0082] A steering plate 24 is provided on the opening 23, and the steering plate 24 is rotatably connected to the base plate 20. Two guide rails 25 are provided on the base plate 20, and the two guide rails 25 are respectively located on both sides of the base plate 20. A moving block 26 is provided on each of the guide rails 25, and the moving block 26 is rotatably connected to the guide rails 25. Each of the moving blocks 26 is provided with a connecting rod 27 connected to the steering plate 24.

[0083] One end of each of the connecting rods 27 is hinged to the steering plate 24 , and the other end of each of the connecting rods 27 is hinged to the moving block 26 .

[0084] One of the moving blocks 26 is connected to an electric push rod 28 via a pull rod 29 , and the electric push rod 28 is fixedly connected to the bottom plate 20 . A baffle 30 for limiting the oil extraction pipe 7 is installed on each of the moving blocks 26 .

[0085] By installing a positioner on the transformer bushing base, the oil extraction port of the transformer bushing can be accurately aligned to ensure the accuracy and stability of the oil extraction process.

[0086] The structures such as the steering plate 24, the guide rail 25, the moving block 26 and the electric push rod 28 on the positioner enable the oil extractor to flexibly adapt to oil extraction ports at different positions and angles, thereby enhancing the versatility and adaptability of the device.

[0087] The drone 1 carries the connector and the oil extractor and flies above the transformer, and preliminarily locates the position of the transformer bushing through the bottom plate 20, the left baffle plate 21 and the right baffle plate 22 on the locator. Then, the position and angle of the oil extractor are precisely adjusted by using the steering plate 24, the guide rail 25, the moving block 26 and the electric push rod 28 to align it with the oil extraction port of the transformer bushing.

[0088] Example 4

[0089] like Figure 1 and Figure 4-6 As shown, a device for extracting oil from a bushing under negative pressure includes a drone 1, a connector fixedly connected to the drone 1, an oil extractor connected to the connector, and a positioner installed on a transformer bushing base.

[0090] The oil extractor includes an outer shell 2, a third needle tube 5 and a fourth needle tube 6 installed in the outer shell 2, and an oil extraction pipe 7 connected to the third needle tube 5 and the fourth needle tube 6 through a conduit 9, a position control capsule 8 is provided at the end of the oil extraction pipe 7, an oil through hole 31 is provided between the position control capsule 8 and the end of the oil extraction pipe 7, and the position control capsule 8 is connected to the first needle tube 3 and the second needle tube 4 through a position control tube 11.

[0091] Here’s how to use it:

[0092] S1. Preparation:

[0093] Ensure that UAV 1, connector, oil extractor and the positioner installed on the transformer bushing base are in good working condition.

[0094] Check whether the connections among the first needle tube 3, the second needle tube 4, the third needle tube 5, the fourth needle tube 6, the position control tube 11, the oil extraction tube 7 and the position control capsule 8 are tight, and ensure that all automatic valves 10 are in the closed state.

[0095] Ensure that the positioner is properly installed on the transformer bushing base and adjust its position to ensure alignment with the oil tapping port.

[0096] S2. Drone 1 take-off and positioning:

[0097] Operate UAV 1 to take off and fly to the transformer area where the locator is installed.

[0098] Connector and oil extractor connection:

[0099] The drone 1 starts to connect with the oil extractor through its fixedly connected connector. Specifically, the clamping claw 17 on the connector, driven by the first motor 13, gradually opens and clamps the clamping block 19 on the oil extractor housing 2 through the interaction of the spiral groove 15 and the slide groove 16.

[0100] The rubber gasket on the clamping jaw 17 ensures that the oil extractor housing 2 will not be damaged during the clamping process, while the ridges on the surface of the clamping block 19 increase the stability of the clamping.

[0101] S3. Adjust the oil extractor position:

[0102] The UAV 1 adjusts its flight attitude and position so that the oil extraction pipe 7 on the oil extractor is aligned with the oil extraction port on the transformer bushing.

[0103] S4, start to extract oil:

[0104] The first needle tube 3 is filled with air, and the second needle tube 4 is filled with insulating oil. When the position control capsule 8 needs to float upward, the automatic valve 10 on the second needle tube 4 is opened, and the automatic valve 10 on the first needle tube 3 is closed. The first needle tube 3 draws the insulating oil in the position control capsule 8 back to the second needle tube 4, and then the automatic valve 10 on the second needle tube 4 is closed, and the automatic valve 10 on the first needle tube 3 is opened, and the first needle tube 3 injects air into the position control tube 11 and the position control capsule 8. When the position control capsule 8 needs to sink, the automatic valve 10 on the first needle tube 3 is opened, and the automatic valve 10 on the second needle tube 4 is closed. The first needle tube 3 draws the air in the position control capsule 8 back to the first needle tube 3, and then the automatic valve 10 on the first needle tube 3 and the automatic valve 10 on the second needle tube 4 are opened, and the second needle tube 4 injects insulating oil into the position control tube 11 and the position control capsule 8.

[0105] In the method of injecting oil into the sleeve, the third needle tube 5 is responsible for extracting oil from the sleeve, and the fourth needle tube 6 is responsible for injecting oil into the sleeve.

[0106] Initial state:

[0107] The position control tube 11, the oil extraction pipe 7 and each pipeline are filled with insulating oil to ensure that no air is introduced into the casing when the pipeline is inserted into the casing;

[0108] The fourth needle tube 6 is filled with low-temperature qualified insulating oil (the low-temperature insulating oil ensures that the insulating oil accumulates at the bottom of the sleeve after being injected into the sleeve and does not move upward), the third needle tube 5 is an empty tube, and the automatic valves 10 on the third needle tube 5 and the fourth needle tube 6 are in a closed state;

[0109] Insert the oil extraction pipe 7 and the position control pipe 11 into the casing along the oil extraction port, and control the position control capsule 8 to sink while inserting;

[0110] Open the automatic valve 10 on the fourth needle tube 6, control the fourth needle tube 6 to inject low-temperature insulating oil into the casing, at this time, the newly injected insulating oil has a low temperature and will gather at the bottom of the casing, and will not move upward until the pressure in the casing increases and the negative pressure is eliminated. The automatic valve 10 on the fourth needle tube 6 controls the position-controlled capsule 8 to float up. After floating, the position of the oil hole 31 changes to ensure that the taken insulating oil is not contaminated by the injected insulating oil;

[0111] At this time, the casing is under positive pressure, and the automatic valve 10 on the third needle tube 5 is opened, and the insulating oil fills the casing and flows into the third needle tube 5 along the oil extraction pipe 7;

[0112] Take 20mL of insulating oil, then close the automatic valve 10 on the third needle tube 5, remove the third needle tube 5, use the 20mL of insulating oil as waste oil for cleaning pipelines and valves, discharge it into the waste oil barrel, connect the third needle tube 5, open the automatic valve 10 on the third needle tube 5 to let the insulating oil flow into the third needle tube 5 to complete the oil extraction work, and then close valve 3.

[0113] S5, finish oil extraction and return;

[0114] S6. Subsequent processing: cleaning and maintaining the oil extractor, the UAV 1 and its connecting parts, and preparing for the next use.

[0115] The oil extraction operation under negative pressure is realized by the design of the position control capsule 8 and the oil through hole 31. This method helps to extract transformer oil samples more thoroughly, while reducing pollution to the environment and damage to the internal structure of the transformer.

[0116] During the oil extraction process, the position control capsule 8 is precisely controlled by controlling the air and insulating oil in the first needle tube 3 and the second needle tube 4, thereby preventing air from entering the transformer bushing. At the same time, when injecting new insulating oil, low-temperature insulating oil is used to ensure that it is accumulated at the bottom of the bushing and does not contaminate the extracted oil sample.

[0117] Before taking the oil, a certain amount of insulating oil is injected as cleaning oil to ensure the cleanliness of the pipeline and valve. Then, the oil is taken formally to improve the accuracy and reliability of the oil sample.

[0118] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0119] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for extracting oil from a casing under negative pressure, characterized in that: It comprises a drone (1), a connector fixedly connected to the drone (1), an oil extractor connected to the connector, and a positioner installed on a transformer bushing base; The oil extractor comprises a housing (2), a third needle tube (5) and a fourth needle tube (6) installed in the housing (2), and an oil extraction pipe (7) connected to the third needle tube (5) and the fourth needle tube (6) through a conduit (9); a position control capsule (8) is provided at the end of the oil extraction pipe (7); an oil through hole (31) is provided between the position control capsule (8) and the end of the oil extraction pipe (7); the position control capsule (8) is connected to the first needle tube (3) and the second needle tube (4) through a position control pipe (11).

2. The device for extracting oil from casing under negative pressure according to claim 1, characterized in that: The third needle tube (5) and the fourth needle tube (6) are connected via a conduit (9); the position control tube (11) is located inside the oil extraction tube (7); automatic valves (10) are provided at the connection points between the third needle tube (5) and the fourth needle tube (6) and the conduit (9) and at the connection points between the first needle tube (3) and the second needle tube (4) and the position control tube (11).

3. The device for extracting oil from casing under negative pressure according to claim 1, characterized in that: The connector comprises a fixing seat (12) connected to the base of the drone (1), a first motor (13) being mounted on the fixing seat (12), a rotating disk (14) being mounted on the transmission shaft of the first motor (13), and a spiral groove (15) being arranged on the rotating disk (14); The fixed seat (12) is provided with four slide grooves (16), each of which is provided with a clamping claw (17), the middle of each of which is slidably connected to each of the slide grooves (16), and the upper end of each of which is fixedly provided with a sliding block (18) adapted to the spiral groove (15), and each of which is slidably connected to the spiral groove (15).

4. The device for extracting oil from casing under negative pressure according to claim 1, characterized in that: The housing (2) is provided with a clamping block (19) for facilitating clamping by the clamping claw (17); the surface of the clamping block (19) is provided with ridges for increasing the roughness; and the lower end of the clamping claw (17) is provided with a rubber gasket.

5. The device for extracting oil from casing under negative pressure according to claim 1, characterized in that: The positioner comprises a base plate (20), a left baffle (21) and a right baffle (22) are mounted on the base plate (20), one end of the left baffle (21) and the right baffle (22) are fixedly mounted on the base plate (20), a gap is arranged between the base plate (20) and the left baffle (21) and the right baffle (22), and a longitudinal positioning structure is arranged on the base plate (20).

6. The device for extracting oil from casing under negative pressure according to claim 5, characterized in that: The bottom plate (20) is provided with an opening (23) which matches the oil inlet of the transformer bushing.

7. The device for extracting oil from casing under negative pressure according to claim 6, characterized in that: A steering plate (24) is provided on the opening (23), and the steering plate (24) is rotatably connected to the bottom plate (20). Two guide rails (25) are provided on the bottom plate (20), and the two guide rails (25) are respectively located on two sides of the bottom plate (20). A moving block (26) is provided on each of the guide rails (25), and the moving block (26) is rotatably connected to the guide rail (25). Each of the moving blocks (26) is provided with a connecting rod (27) connected to the steering plate (24).

8. The device for extracting oil from casing under negative pressure according to claim 7, characterized in that: One end of each of the connecting rods (27) is hinged to the rotating plate, and the other end of each of the connecting rods (27) is hinged to the moving block (26).

9. The device for extracting oil from casing under negative pressure according to claim 8, characterized in that: One of the moving blocks (26) is connected to an electric push rod (28) via a pull rod (29), and the electric push rod (28) is fixedly connected to the base plate (20). Each of the moving blocks (26) is equipped with a baffle (30) for limiting the oil extraction pipe (7).

10. A method for extracting oil from a casing under negative pressure, based on any device for extracting oil under negative pressure according to any one of claims 1 to 9, characterized in that: Here’s how to use it: S1. Preparation: Ensure that the drone (1), connector, oil extractor and positioner installed on the transformer bushing base are in good working condition; check whether the first needle tube (3), the second needle tube (4), the third needle tube (5), the fourth needle tube (6), the position control tube (11), the oil extraction pipe (7) and the position control capsule (8) are tightly connected, and ensure that all automatic valves (10) are in the closed state; ensure that the positioner is correctly installed on the transformer bushing base, and adjust its position to ensure that it is aligned with the oil extraction port; S2, take-off and positioning of the UAV (1): the UAV (1) is operated to take off and fly to the transformer area where the positioner is installed; the connector is connected to the oil extractor, and the UAV (1) begins to connect with the oil extractor through its fixedly connected connector. Specifically, the clamping claw (17) on the connector is driven by the first motor (13) and gradually opens and clamps the clamping block (19) on the oil extractor housing (2) through the interaction of the spiral groove (15) and the slide groove (16); S3. Adjust the oil extractor position: The UAV (1) adjusts its flight attitude and position so that the oil extraction pipe (7) on the oil extraction device is aligned with the oil extraction port on the transformer bushing; S4, start to extract oil: The first needle tube (3) is filled with air, and the second needle tube (4) is filled with insulating oil. When the position control capsule (8) needs to float upward, the automatic valve (10) on the second needle tube (4) is opened, and the automatic valve (10) on the first needle tube (3) is closed to draw the insulating oil in the position control capsule (8) back to the second needle tube (4). Then, the automatic valve (10) on the second needle tube (4) is closed and the automatic valve (10) on the first needle tube (3) is opened. The first needle tube (3) injects air into the position control capsule (11 ) and the position control capsule (8), when the position control capsule (8) needs to sink downward, the automatic valve (10) on the first needle tube (3) is opened, and the automatic valve (10) on the second needle tube (4) is closed, the first needle tube (3) draws the air in the position control capsule (8) back into the first needle tube (3), then the automatic valve (10) on the first needle tube (3) is closed, and the automatic valve (10) on the second needle tube (4) is opened, and the second needle tube (4) injects insulating oil into the position control tube (11) and the position control capsule (8); A method for injecting oil into the casing, wherein the third needle tube (5) is responsible for extracting oil from the casing, and the fourth needle tube (6) is responsible for injecting oil into the casing; Initial state: The position control pipe (11), the oil extraction pipe (7) and each pipeline are filled with insulating oil to ensure that no air is introduced into the casing when the pipeline is inserted into the casing; The fourth needle tube (6) is filled with low-temperature qualified insulating oil (the low-temperature insulating oil ensures that the insulating oil accumulates at the bottom of the sleeve after being injected into the sleeve and does not move upward), the third needle tube (5) is an empty tube, and the automatic valves (10) on the third needle tube (5) and the fourth needle tube (6) are in a closed state; Insert the oil extraction pipe (7) and the position control pipe (11) into the casing along the oil extraction port; while inserting, control the position control capsule (8) to sink; The automatic valve (10) on the fourth needle tube (6) is opened, and the fourth needle tube (6) is controlled to inject low-temperature insulating oil into the casing. At this time, the newly injected insulating oil has a low temperature and will gather at the bottom of the casing and will not move upward until the pressure in the casing increases and the negative pressure is eliminated. The automatic valve (10) on the fourth needle tube (6) is closed, and the position-controlled capsule (8) is controlled to float up. After floating up, the position of the oil hole (31) changes to ensure that the insulating oil taken out is not contaminated by the injected insulating oil. At this time, the casing is under positive pressure, the automatic valve (10) on the third needle tube (5) is opened, and the insulating oil fills the casing and flows into the third needle tube (5) along the oil extraction pipe (7); Take 20 mL of insulating oil, then close the automatic valve (10) on the third needle tube (5), remove the third needle tube (5), use the 20 mL of insulating oil taken as waste oil for cleaning the pipelines and the automatic valve (10), and drain it into a waste oil barrel, connect the third needle tube (5), open the automatic valve (10) on the third needle tube (5) to allow the insulating oil to flow into the third needle tube (5) to complete the oil taking work, and then close the automatic valve (10) on the third needle tube (5). S5, finish oil extraction and return; S6. Subsequent processing: Clean and maintain the oil extractor, the drone (1) and its connected parts, and prepare for the next use.

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