Nitrogen charging control device for oil immersed transformer

Abstract

The invention belongs to the technical field of power equipment, and particularly relates to an oil immersed transformer nitrogen charging control device which comprises a high-pressure nitrogen cylinder and a touch screen, one end of the high-pressure nitrogen cylinder is connected with a pressure reducing valve, and the end, away from the high-pressure nitrogen cylinder, of the pressure reducing valve is provided with a first quick connector; the end, away from the pressure reducing valve, of the first quick connector is connected with a first hose. According to the automatic nitrogen charging control device of the oil immersed transformer, automatic judgment of technological parameters is achieved, the system automatically completes the nitrogen charging process, and the automatic nitrogen charging control device has the specific advantages that the automation degree is high, the nitrogen charging process is automatically carried out, and the running state is displayed through the state display lamp. Nitrogen charging pressure precision is high, and high-precision control over the pressure intensity of the top of the transformer oil tank can be achieved by setting a threshold value. The safety is good, and the process control pressure P is strictly and theoretically calculated, so that the safety of the oil tank of the transformer in an extreme state is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of electric power equipment, in particular to a nitrogen charging control device for an oil-immersed transformer. Background Art

[0002] In different seasons, different ambient temperatures, and different insulating oil temperatures, the nitrogen pressure filled into the upper space must be maintained within a reasonable range to ensure product safety regardless of whether the transformer is stored at low temperatures or operated at extremely high temperatures. It is necessary to ensure that the internal space pressure is maintained at a slightly positive pressure when the liquid level is at its lowest to prevent the transformer from absorbing moisture, and also to ensure that when the liquid level is at its highest under extremely high temperatures, the pressure generated by the compressed nitrogen does not exceed the design strength of the oil tank and cause damage to the oil tank.

[0003] Traditionally, nitrogen filling of oil-immersed transformers is mainly done manually. Generally, when the pressure is reduced to below 100kPa through a pressure reducing valve, it is connected to the air inlet of the oil-immersed transformer through a hose, and then the oil tank air inlet pressure is checked at any time, and the nitrogen pressure at the top of the transformer tank is manually controlled between 10kPa-30kPa. Since high-precision pressure gauges are generally not installed on the transformer tank body, gas needs to be transmitted under a certain pressure difference. The pressure gauge on the air pipe cannot reflect the gas pressure at the top of the transformer tank, so manual adjustment is difficult to meet the control requirements. The top pressure control requirement of 10kPa-30kPa is empirical data. In fact, the size of the top pressure of the transformer tank is closely related to the actual working conditions and the mechanical strength of the transformer tank. If the top pressure is too high or too low, there will be some safety hazards.

[0004] The traditional nitrogen filling method mainly has the problems of manual operation, time-consuming and labor-intensive, and low control accuracy. At the same time, the pressure control requirements on the top of the transformer oil tank can only rely on empirical data, which is difficult to be accurate. Moreover, under extreme working conditions, the pressure on the top of the transformer oil tank may exceed the mechanical strength of the tank or generate negative pressure, posing a safety hazard.

[0005] To this end, the present invention provides a nitrogen charging control device for an oil-immersed transformer. Summary of the invention

[0006] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0007] The technical solution adopted by the present invention to solve its technical problem is: a nitrogen charging control device for an oil-immersed transformer described in the present invention comprises a high-pressure nitrogen cylinder and a touch screen, one end of the high-pressure nitrogen cylinder is connected to a pressure reducing valve, one end of the pressure reducing valve away from the high-pressure nitrogen cylinder is equipped with a first quick connector, one end of the first quick connector away from the pressure reducing valve is connected to a first hose, one end of the first hose away from the first quick connector is equipped with an intake pipe through a second quick connector, an intake pressure gauge, a proportional valve, a solenoid valve and a first pressure gauge are installed on the intake pipe, an outlet pipe is installed at one end of the intake pipe, a second hose is installed at one end of the outlet pipe through a third quick connector, and one end of the second hose is connected to the top of the oil tank through a fourth quick connector; the touch screen is connected to a controller, the controller is connected to a display light, an intake pressure gauge, a proportional valve, a solenoid valve and a first pressure gauge through a communication bus, the controller is connected to a magnetic thermal resistor through a communication bus, and the magnetic thermal resistor is connected to the oil tank; a detection mechanism for detecting the pipeline is installed on the intake pipe.

[0008] Furthermore, the detection mechanism includes a connecting frame connected to the air intake pipe through a ring, a servo motor is installed inside the connecting frame, a lead screw is installed at the output end of the servo motor, the end of the lead screw away from the servo motor is connected to the connecting frame, and the surface of the lead screw is movably connected to a movable frame; an electric push rod is fixedly installed in the movable frame, a push plate is fixedly installed at the output end of the electric push rod, an arc-shaped sliding frame is slidably connected in the movable frame, an ultrasonic probe is fixedly installed in the sliding frame, and the ultrasonic probe is connected to the controller and the touch screen through a signal line.

[0009] Furthermore, a blowing mechanism is provided in the movable frame, and the blowing mechanism includes two elastic blocks fixedly installed in the movable frame, a first cavity is provided at the bottom of the elastic block, pressure blocks are fixedly installed on both sides of the sliding frame, an air jet is fixedly installed in the movable frame, the air outlet end of the air jet is aligned with the ultrasonic probe, and one end of the air jet is connected to the first cavity; a protective component is provided in the movable frame.

[0010] Furthermore, the protective component includes a first magnetic block arranged at one end of the pressure block, a hollow fixed column is fixedly installed in the movable frame, a pressure plate is sealingly and slidably connected in the fixed column, a second magnetic block is fixedly installed on one side of the pressure plate, a spring is fixedly installed between the second magnetic block and the fixed column, the second magnetic block is sealingly and slidably connected to the fixed column, a hollow fixed rod is fixedly installed on one side of the movable frame, the fixed rod and the fixed column are connected by a pipe, a sliding rod is sealingly and slidably connected inside the fixed rod through an elastic member, and a protective plate is fixedly connected to the end of the sliding rod away from the fixed rod.

[0011] Furthermore, the movable frame refers to a marking mechanism, which includes two loading boxes fixedly installed in the movable frame, the loading boxes are made of hollow rubber material, a liquid guide tube with a one-way valve is fixedly installed on one side of the loading box, the end of the liquid guide tube away from the loading box is aligned with the air inlet pipe, a liquid inlet pipe connected to the interior is installed on one side of the loading box, an electromagnet is fixedly installed in the loading box, and the first magnetic block is slidably connected through a spring and a pressure block.

[0012] Furthermore, two symmetrically arranged side panels are fixedly mounted on one side of the first magnetic block, and the side panels are arc-shaped.

[0013] Furthermore, an end cap is rotatably connected to the port of the liquid guiding tube, and a first elastic ball is fixedly installed between the end cap and the liquid guiding tube.

[0014] Furthermore, a hollow rolled film is fixedly installed at the bottom of the liquid guiding tube, and the rolled film and the first elastic ball are connected through a connecting tube.

[0015] Furthermore, a curved limiting rod made of rubber is fixedly mounted on one side of the end cover, and a limiting groove matched with the limiting rod is provided in the liquid guiding tube.

[0016] Furthermore, a maintenance mechanism is provided in the movable frame, and the maintenance mechanism includes a second cavity in the elastic block. Two arc-shaped placement frames are slidably connected in the sliding frame, and a maintenance block is provided in the placement frame. A plurality of second elastic balls are fixedly installed between the placement frame and the sliding frame, and the second elastic balls are connected to the second cavity through an air guide tube.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The oil-immersed transformer nitrogen charging control device described in the present invention realizes automatic determination of process parameters through the automatic nitrogen charging control device for the oil-immersed transformer provided, and the system automatically completes the nitrogen charging process. The specific advantages are as follows: high degree of automation, automatic nitrogen charging process, and the operating status is displayed by the status display light. The nitrogen charging pressure has high accuracy, and the top pressure of the transformer oil tank can be controlled with high accuracy through threshold setting. Good safety, the process control pressure P is strictly calculated by theory to ensure the safety of the transformer oil tank under extreme conditions.

[0019] 2. The oil-immersed transformer nitrogen charging control device described in the present invention allows the output end of the servo motor to move with the movable frame and the sliding frame through the screw rod. When the sliding frame moves, it will carry the ultrasonic probe to detect the air inlet and outlet pipes, and transmit the detection results to the touch screen in real time, so that the staff can understand the detection results. Through the designed detection mechanism, regular detection of pipelines such as the air inlet and outlet pipes is achieved without manual detection, thereby improving the detection efficiency. At the same time, the detection results are directly displayed on the touch screen, which is convenient for the staff to quickly understand the detection results.

[0020] 3. The nitrogen charging control device for oil-immersed transformers described in the present invention attracts each other through the first magnetic block and the second magnetic block. The second magnetic block slides with the pressure plate in the fixed column toward the first magnetic block. Since the pressure plate and the fixed column are sealed and slidably connected, the gas in the fixed column is sucked in through the pipeline, forcing the sliding rod to slide and shrink with the guard plate into the fixed rod, thereby exposing the end of the ultrasonic probe, which is convenient for the ultrasonic probe to perform detection. The moving sliding frame will squeeze the first cavity in the elastic block with the pressure plates on both sides, so that the gas in the first cavity is sprayed to the end of the ultrasonic probe through the jet pipe, thereby cleaning the ultrasonic probe and reducing the influence of dust and impurities on its surface on the detection. When the detection is completed, the guard plate can still cover the end of the ultrasonic probe and protect it.

[0021] 4. The nitrogen charging control device for oil-immersed transformers described in the present invention slides and squeezes the side plate toward the loading box through the first magnetic block, so that the liquid used for marking in the loading box is sprayed toward the problematic part of the air inlet pipe or the air outlet pipe through the liquid guide tube. The rolled film unfolded by the brush is used to catch the flowing liquid, thereby reducing the pollution and waste after the liquid flows out. Through the designed marking mechanism, when inspecting pipelines such as the air inlet pipe and the air outlet pipe, if a problem is found in the pipeline, it can be marked immediately, so that subsequent staff can quickly locate the problematic pipeline and replace or repair it.

[0022] 5. The nitrogen charging control device for oil-immersed transformers described in the present invention squeezes the second cavity of the elastic block through the pressing block, so that the gas in the second cavity enters into a plurality of second elastic balls through the air duct, so that the second elastic balls expand after being filled with gas, and then push the placement frame and the maintenance block to move away from the movable frame, so that the maintenance block in the placement frame fits with the surface of the pipeline, and the pipeline can be coated and maintained after long-term use. The designed plurality of second elastic balls can carry the maintenance block to adapt to pipelines of different diameters, and always fit tightly with the surface of the pipeline, so as to achieve maintenance and maintenance of the pipeline. When the movable frame is reset and not in use, the gas in the second elastic ball will return to the second cavity, so that the placement frame and the maintenance block can be reset to the sliding frame and wait for the next use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below in conjunction with the accompanying drawings.

[0024] Figure 1 It is a schematic diagram of the process of the automatic nitrogen filling control device of the oil-immersed transformer in the present invention;

[0025] Figure 2 It is a structural schematic diagram of the air intake pipe in the present invention;

[0026] Figure 3 It is a structural schematic diagram of the connection frame in the present invention;

[0027] Figure 4 It is a structural schematic diagram of the servo motor in the present invention;

[0028] Figure 5 It is a structural schematic diagram of the movable frame in the present invention;

[0029] Figure 6 It is a side cross-sectional structural schematic diagram of the movable frame in the present invention;

[0030] Figure 7 The present invention Figure 5 A schematic diagram of the structure at A;

[0031] Figure 8 The present invention Figure 5 Schematic diagram of the structure at B;

[0032] Fig. 9 It is a schematic cross-sectional structural diagram of the loading box in the present invention;

[0033] Fig.10 It is a schematic cross-sectional structural diagram of the liquid guiding tube in the present invention;

[0034] Fig.11 It is a schematic cross-sectional structural diagram of the fixing column in the present invention.

[0035] In the figure: 1. High-pressure nitrogen cylinder; 2. Pressure reducing valve; 3. First quick connector; 4. First hose; 5. Second quick connector; 6. Inlet pressure gauge; 7. Proportional valve; 8. Solenoid valve; 9. First pressure gauge; 10. Inlet pipe; 11. Third quick connector; 12. Second hose; 13. Outlet pipe; 14. Magnetic thermal resistor; 15. Display light; 16. Fourth quick connector; 17. Communication bus; 18. Touch screen; 19. Controller;

[0036] 20. Detection mechanism; 21. Ring; 22. Connection frame; 23. Servo motor; 24. Screw rod; 25. Movable frame; 26. Electric push rod; 27. Push plate; 28. Sliding frame; 29. ​​Ultrasonic probe;

[0037] 30. Blowing mechanism; 31. Elastic block; 32. First cavity; 33. Pressing block; 34. Jet pipe;

[0038] 35, protection assembly; 351, first magnetic block; 352, fixed column; 353, second magnetic block; 354, pressure plate; 355, fixed rod; 356, sliding rod; 357, guard plate;

[0039] 40. marking mechanism; 41. loading box; 42. electromagnet; 43. liquid guiding tube; 44. side plate; 45. end cover; 46. first elastic ball; 47. film roll; 48. limit rod; 49. limit groove;

[0040] 50. Maintenance mechanism; 51. Second cavity; 52. Placement frame; 53. Maintenance block; 54. Second elastic ball. DETAILED DESCRIPTION

[0041] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0042] like Figures 1 to 11 As shown, a nitrogen charging control device for an oil-immersed transformer described in an embodiment of the present invention includes a high-pressure nitrogen cylinder 1 and a touch screen 18, one end of the high-pressure nitrogen cylinder 1 is connected to a pressure reducing valve 2, and the end of the pressure reducing valve 2 away from the high-pressure nitrogen cylinder 1 is equipped with a first quick connector 3, the end of the first quick connector 3 away from the pressure reducing valve 2 is connected to a first hose 4, the end of the first hose 4 away from the first quick connector 3 is equipped with an intake pipe 10 through a second quick connector 5, the intake pipe 10 is equipped with an intake pressure gauge 6, a proportional valve 7, a solenoid valve 8 and a first pressure gauge 9, one end of the intake pipe 10 is equipped with an outlet pipe 13, one end of the outlet pipe 13 is equipped with a second hose 12 through a third quick connector 11, and one end of the second hose 12 is connected to the top of the oil tank through a fourth quick connector 16.

[0043] Specifically, the touch screen 18 is connected to the controller 19, and the controller 19 is connected to the display light 15, the intake pressure gauge 6, the proportional valve 7, the solenoid valve 8 and the first pressure gauge 9 through the communication bus 17. The controller 19 is connected to the magnetic thermal resistor 14 through the communication bus 17, and the magnetic thermal resistor 14 is connected to the fuel tank.

[0044] During operation, relevant parameters of the oil-immersed transformer oil tank are input into the touch screen 18, mainly including the inner dimension length (L0, in mm), inner dimension width (W0, in mm), inner dimension height (H0, in mm), body weight (Weight, in kg), the distance between the top of the body and the bottom of the tank (H1, in mm), oil filling level (H2, in mm), oil expansion coefficient (α, in % / K), minimum ambient temperature (T1, in °C), maximum ambient temperature (T2, in °C), average oil temperature rise (ΔT1, in K), top oil temperature rise (ΔT2, in K), oil density (ρ, in kg / l), mechanical strength of the oil tank (σb, in kPa), process control pressure (P0, in kPa), and the touch screen 1818 transmits these data to the controller 19 via communication. The temperature during oil filling (T3, in °C) is measured by the magnetic thermal resistor 14 and directly transmitted to the controller 19.

[0045] The controller 19 calculates the obtained setting parameters to determine the given process control pressure P0, and calculates the gas phase space pressure (P1, unit kPa) under the lowest temperature storage state and the box bottom pressure P2 under the highest temperature full load operation state, unit kPa). The main calculation process is as follows:

[0046] 1. Calculate the volume of the fuel tank (V0, unit: dm3), V0 = L0*W0*H0 / 1000000.0;

[0047] 2. Calculate the body volume (V1, unit dm3), V1 = Weight * 1.15 / 5.3;

[0048] 3. Calculate the oil volume (V2, unit dm3), V2 = V0-V1-(H0-H2)*L0*W0 / 1000000.0;

[0049] 4. Calculate the gas space after oil filling (V3, unit dm3), V3 = (H0-H2)*L0*W0 / 1000000.0;

[0050] 5. Calculate the gas constant (K), K = V3*P0 / (T3+273.18);

[0051] 6. Calculate the gas volume (V4, unit dm3) under the lowest temperature storage state, V4 = V3-V2*α*(T1-T3);

[0052] 7. Calculate the gas volume (V5, unit dm3) under the condition of maximum temperature and full load operation, V5 = V3-V2*ρ*(T2-T3);

[0053] 8. Calculate the top pressure P1 of the oil tank under the lowest temperature storage state, P1 = K*(273.18+T1) / V4;

[0054] 9. Calculate the oil level height (H3, unit: mm) under the condition of maximum temperature and full load operation, H3 = H2 + V2*ρ*(T2-T3*1000000.0 / (L0*W0);

[0055] 10. Calculate the bottom pressure P2 of the box under the condition of maximum temperature and full load operation, P2 = ρ*9.18*H3+K*(273.18+T2) / V5;

[0056] The process control pressure P0 is generally set at 10kPa-30kPa. The smaller the parameter, the better. If the P0 parameter is set so that the calculation result satisfies P1≥5kPa and P2<σb (mechanical strength of the oil tank), the process parameters meet the requirements and the nitrogen filling control can be put into automatic operation. Otherwise, an error message will be displayed on the touch screen 18, and the parameters need to be corrected before it can be put into automatic operation. The controller 19 is connected to the intake pressure gauge 6, the outlet pressure gauge and the proportional valve 7 through the bus, and typically communicates based on the Modbus bus. The controller 19 reads the intake pressure (P3, unit kPa) information and the outlet pressure (P4, unit kPa) information in real time and displays them on the touch screen 18.

[0057] The function of the pressure reducing valve 2 is to adjust the pressure to a working pressure between 1MPa and 2MPa. When the device is automatically put into operation, when the controller 19 detects that the intake pressure P3 is within the working pressure range, it controls the opening of the status display light 15, opens the solenoid valve 8, and writes the value of the controlled process parameter P0 into the proportional valve 7 through communication, thereby starting the proportional valve 7.

[0058] The controller 19 periodically closes the solenoid valve 8, typically for 5 seconds every 2 minutes. After the battery valve is closed, the outlet pressure P4 basically reflects the pressure of the transformer tank. When the controller 19 closes the solenoid valve 8, when the deviation between the outlet pressure P4 and the process control pressure P0 is within a certain threshold, it is considered that the automatic nitrogen filling process is completed. The controller 19 communicates and writes 0 as the set value of the pressure output into the proportional valve 7 to close the output of the proportional valve 7, and controls the closed state display light 15 at the same time.

[0059] The automatic nitrogen filling control device for oil-immersed transformers provided in the present application realizes automatic determination of process parameters, and the system automatically completes the nitrogen filling process. The specific advantages are as follows: high degree of automation, the nitrogen filling process is automatically carried out, and the operating status is displayed by the status display light 15. The nitrogen filling pressure has high accuracy, and the pressure at the top of the transformer oil tank can be controlled with high accuracy through threshold setting. Good safety, the process control pressure P0 is strictly calculated theoretically to ensure the safety of the transformer oil tank under extreme conditions.

[0060] The relevant parameters of the oil-immersed transformer tank are input into the touch screen 18, and the parameters are integrated into the controller 19 through communication. The touch screen 18 can also display the current inlet and outlet pressures, as well as prompt information such as whether the set process control pressure P0 meets the requirements, and can also realize the visual display of the nitrogen filling process. After the controller 19 integrates the required parameters, it calculates whether the set process control pressure P0 meets the safety requirements. If it does, it can be put into automatic use, otherwise the parameters need to be reset. When the device is put into automatic use, the controller 19 first detects whether the working pressure meets the requirements (normally 1MPa-2MPa) through the intake pressure gauge 6. If it meets the requirements, it controls the opening of the status display light 15, opens the solenoid valve 8, and writes the process control pressure P0 into the proportional valve 7 to start the proportional valve 7. The controller 19 periodically switches the solenoid valve 8, and determines the bias between the outlet pressure P4 detected by the first outlet pressure gauge 9 after closing the solenoid valve 8 and the set process control pressure P0. If it is less than the preset threshold, the nitrogen filling process is completed, the solenoid valve 8 is closed, the status display light 15 is turned off, and 0 is written into the proportional valve 7 to complete the closing of the proportional valve 7.

[0061] For the automatic nitrogen filling control of a given oil-immersed transformer, the given parameter conditions are shown in Table 1, and the analysis and calculation results are shown in Table 1. The calculation results show that the set process control pressure of 10kPa meets the safety operation requirements and can be put into automatic use. The system has been tested for 10 automatic nitrogen filling tests. The test results are shown in Table 2. The average nitrogen filling time is 16 minutes and the control accuracy is within 2%.

[0062] Table 1 Typical chromatographic analysis conditions.

[0063]

[0064]

[0065] Table 1

[0066]

[0067] Table 2

[0068] The air intake pipe 10 is provided with a detection mechanism 20 for detecting the pipeline. The detection mechanism 20 includes a connection frame 22 connected to the air intake pipe 10 through a collar 21. A servo motor 23 is installed inside the connection frame 22. A lead screw 24 is installed at the output end of the servo motor 23. The end of the lead screw 24 away from the servo motor 23 is connected to the connection frame 22. A movable frame 25 is movably connected to the surface of the lead screw 24. An electric push rod 26 is fixedly installed inside the movable frame 25. A push plate 27 is fixedly installed at the output end of the electric push rod 26. An arc-shaped sliding frame 28 is slidably connected inside the movable frame 25. An ultrasonic probe 29 is fixedly installed inside the sliding frame 28. The ultrasonic probe 29 is connected to the controller 19 and the touch screen 18 through a signal line.

[0069] During operation, after the air inlet pipe 10 and the air outlet pipe 13 have been transporting high-pressure liquid nitrogen for a long time, they need to be inspected regularly. At this time, the servo motor 23 in the connection frame 22 is started, and the output end of the servo motor 23 is moved together with the movable frame 25 and the sliding frame 28 through the screw rod 24. When the sliding frame 28 moves, it will carry the ultrasonic probe 29 to detect the air inlet pipe 10 and the air outlet pipe 13, and transmit the detection results to the touch screen 18 in real time, so as to facilitate the staff to understand the detection results. When the servo motor 23 reverses and moves and resets with the movable frame 25 and the sliding frame 28, the electric push rod 26 in the movable frame 25 is started, and the sliding frame 28 and the ultrasonic probe 29 are pushed by the electric push rod 26 with the push plate 27, thereby changing the detection position of the ultrasonic probe 29, and then the air inlet pipe 10 and the air outlet pipe 13 are detected in all directions.

[0070] Through the detection mechanism 20 designed in the present application, regular detection of pipelines such as the air inlet pipe 10 and the air outlet pipe 13 can be achieved without manual detection, thereby improving the detection efficiency. At the same time, the detection results are directly displayed through the touch screen 18, which is convenient for the staff to quickly understand the detection results.

[0071] The movable frame 25 is provided with a blowing mechanism 30, and the blowing mechanism 30 includes two elastic blocks 31 fixedly installed in the movable frame 25, and a first cavity 32 is provided at the bottom of the elastic block 31. Pressing blocks 33 are fixedly installed on both sides of the sliding frame 28. An air jet pipe 34 is fixedly installed in the movable frame 25, and the air outlet end of the air jet pipe 34 is aligned with the ultrasonic probe 29, and one end of the air jet pipe 34 is connected to the first cavity 32.

[0072] Specifically, a protective component 35 is provided in the movable frame 25, and the protective component 35 includes a first magnetic block 351 arranged at one end of the pressure block 33, a hollow fixed column 352 is fixedly installed in the movable frame 25, and a pressure plate 354 is sealed and slidably connected in the fixed column 352, a second magnetic block 353 is fixedly installed on one side of the pressure plate 354, a spring is fixedly installed between the second magnetic block 353 and the fixed column 352, the second magnetic block 353 is sealed and slidably connected to the fixed column 352, a hollow fixed rod 355 is fixedly installed on one side of the movable frame 25, the fixed rod 355 and the fixed column 352 are connected by a pipe, a sliding rod 356 is sealed and slidably connected inside the fixed rod 355 through an elastic member, and a protective plate 357 is fixedly connected to the end of the sliding rod 356 away from the fixed rod 355.

[0073] During operation, when the sliding frame 28 moves with the ultrasonic probe 29 and performs detection, the first magnetic block 351 (the first magnetic block 351 needs to be energized to have magnetic force, and it needs to be energized when needed) and the second magnetic block 353 attract each other, and the second magnetic block 353 slides toward the first magnetic block 351 with the pressure plate 354 in the fixed column 352. Since the pressure plate 354 and the fixed column 352 are sealed and slidably connected, the gas in the fixed column 352 will be sucked in through the pipeline, forcing the sliding rod 356 to slide and retract with the protective plate 357 into the fixed rod 355, thereby exposing the end of the ultrasonic probe 29, which is convenient for the ultrasonic probe 29 to perform detection work.

[0074] When the detection position changes, that is, the electric push rod 26 moves the movable frame 25 through the push plate 27, so that the first magnetic block 351 is powered off, the second magnetic block 353 resets the pressure plate 354, and the sliding rod 356 and the guard plate 357 are also reset. At this time, the ultrasonic probe 29 moves with the sliding frame 28, so the guard plate 357 will not hinder the ultrasonic probe 29 from detecting. The moving sliding frame 28 will squeeze the first cavity 32 in the elastic block 31 with the pressure plates 354 on both sides, so that the gas in the first cavity 32 is sprayed to the end of the ultrasonic probe 29 through the jet pipe 34, thereby cleaning the ultrasonic probe 29 and reducing the influence of dust and impurities on its surface on the detection. When the detection is completed, the guard plate 357 can still cover the end of the ultrasonic probe 29 and protect it.

[0075] The movable frame 25 contains a marking mechanism 40, which includes two loading boxes 41 fixedly installed in the movable frame 25. The loading boxes 41 are made of hollow rubber. A liquid guide tube 43 with a one-way valve is fixedly installed on one side of the loading box 41. The end of the liquid guide tube 43 away from the loading box 41 is aligned with the air inlet pipe 10. A liquid inlet pipe connected to the interior is installed on one side of the loading box 41. An electromagnet 42 is fixedly installed in the loading box 41, and the first magnetic block 351 is slidably connected to the pressure block 33 through a spring.

[0076] Specifically, two symmetrically arranged side plates 44 are fixedly mounted on one side of the first magnetic block 351, and the side plates 44 are arc-shaped. An end cap 45 is rotatably connected to the port of the liquid guiding tube 43, and a first elastic ball 46 is fixedly mounted between the end cap 45 and the liquid guiding tube 43. A hollow roll film 47 is fixedly mounted on the bottom of the liquid guiding tube 43, and the roll film 47 and the first elastic ball 46 are connected through a connecting tube. An arc-shaped limit rod 48 made of rubber material is fixedly mounted on one side of the end cap 45, and a limit groove 49 adapted to the limit rod 48 is provided in the liquid guiding tube 43.

[0077] During operation, when the ultrasonic probe 29 detects a problem at a certain point of the air inlet pipe 10 or the air outlet pipe 13, the electric push rod 26 is started, and the electric push rod 26 is used to drive the sliding frame 28 and the pressing plate 354 to slide upward. When the pressing plate 354 moves to the loading box 41 with the first block, the first magnetic block 351 and the electromagnet 42 in the loading box 41 are energized, and the first magnetic block 351 will slide and squeeze the side plate 44 toward the loading box 41, so that the liquid used for marking in the loading box 41 is sprayed to the problematic part of the air inlet pipe 10 or the air outlet pipe 13 through the liquid guide tube 43.

[0078] When the liquid enters the air guide tube, the end cover 45 will be rotated to open, so that the end cover 45 and the limiting rod 48 will rotate and snap into the limiting groove 49. At the same time, the cover plate will squeeze the first elastic ball 46, so that the gas in the first elastic ball 46 will enter the roll film 47 through the connecting pipe, and the roll film 47 will be quickly unfolded with an air brush. When the liquid used for marking cannot be dried immediately after being sprayed out, a small amount of liquid will flow down. At this time, the roll film 47 that is unfolded by the brush will catch the flowing liquid, thereby reducing the pollution and waste after the liquid flows. When the liquid guide tube 43 is no longer in use, the end cover 45 is no longer impacted, and rotates and resets under the action of the first elastic ball 46. The gas in the roll film 47 flows back into the first elastic ball 46. At the same time, the limiting rod 48 is separated from the limiting groove 49, and the end cover 45 is used to close the port of the liquid guide tube 43 to reduce the entry of impurities.

[0079] By means of the marking mechanism 40 designed in the present application, when inspecting pipes such as the air inlet pipe 10 and the air outlet pipe 13, if problems are found in the pipes, they can be marked immediately, thereby facilitating subsequent staff to quickly locate the problematic pipes and replace or repair them.

[0080] A maintenance mechanism 50 is provided in the movable frame 25, and the maintenance mechanism 50 includes a second cavity 51 in the elastic block 31. Two arc-shaped placement frames 52 are slidably connected in the sliding frame 28, and a maintenance block 53 is provided in the placement frame 52. A plurality of second elastic balls 54 are fixedly installed between the placement frame 52 and the sliding frame 28, and the second elastic balls 54 and the second cavity 51 are connected through an air guide tube.

[0081] During operation, before using the movable frame 25, the maintenance block 53 (which can be made of anti-corrosion material, such as epoxy resin, and a suitable material is selected according to actual conditions) is first placed in the placement frame 52. At this time, one side of the maintenance block 53 does not contact the surface of the pipeline. As the sliding frame 28 moves with the pressing block 33, the pressing block 33 squeezes the second cavity 51 of the elastic block 31, so that the gas in the second cavity 51 enters the plurality of second elastic balls 54 through the air guide tube, so that the second elastic balls 54 are filled with gas and expand, thereby pushing the placement frame 52 and the maintenance block 53 to move away from the movable frame 25, so that the maintenance block 53 in the placement frame 52 fits with the surface of the pipeline, and realizes the application and maintenance of the pipeline after long-term use. The plurality of second elastic balls 54 designed can carry the maintenance block 53 to adapt to pipelines of different diameters, and always fit closely with the surface of the pipeline, so as to realize the maintenance and maintenance of the pipeline. When the movable frame 25 is reset and not in use, the gas in the second elastic ball 54 will return to the second cavity 51, thereby allowing the placement frame 52 and the maintenance block 53 to reset to the sliding frame 28 and wait for the next use.

[0082] Working principle: Input the relevant parameters of the oil-immersed transformer tank into the touch screen 18, and integrate the parameters into the controller 19 through communication. The touch screen 18 can also display the current inlet and outlet pressures, as well as prompt information such as whether the set process control pressure P0 meets the requirements, and can also realize the visual display of the nitrogen filling process. After the controller 19 integrates the required parameters, it calculates whether the set process control pressure P0 meets the safety requirements. If it does, it can be put into automatic use, otherwise the parameters need to be reset. When the device is put into automatic use, the controller 19 first detects whether the working pressure meets the requirements (normally 1MPa-2MPa) through the intake pressure gauge 6. If it meets the requirements, it controls the opening of the status display light 15, opens the solenoid valve 8, and writes the process control pressure P0 into the proportional valve 7 to start the proportional valve 7. The controller 19 periodically switches the solenoid valve 8, and determines the bias between the outlet pressure P4 detected by the first outlet pressure gauge 9 after closing the solenoid valve 8 and the set process control pressure P0. If it is less than the preset threshold, the nitrogen filling process is completed, the solenoid valve 8 is closed, the status display light 15 is turned off, and 0 is written into the proportional valve 7 to complete the closing of the proportional valve 7.

[0083] After the air inlet pipe 10 and the air outlet pipe 13 have been transporting high-pressure liquid nitrogen for a long time, they need to be inspected regularly. At this time, the servo motor 23 in the connection frame 22 is started, and the output end of the servo motor 23 is moved together with the movable frame 25 and the sliding frame 28 through the screw rod 24. When the sliding frame 28 moves, it will carry the ultrasonic probe 29 to detect the air inlet pipe 10 and the air outlet pipe 13. When the servo motor 23 is reversed and moves and resets with the movable frame 25 and the sliding frame 28, the electric push rod 26 in the movable frame 25 is started, and the sliding frame 28 and the ultrasonic probe 29 are pushed by the electric push rod 26 with the push plate 27, thereby changing the detection position of the ultrasonic probe 29, and then the air inlet pipe 10 and the air outlet pipe 13 are detected in all directions.

[0084] When the sliding frame 28 moves with the ultrasonic probe 29 and performs detection, the first magnetic block 351 and the second magnetic block 353 attract each other, and the second magnetic block 353 slides with the pressure plate 354 in the fixed column 352 toward the first magnetic block 351. Since the pressure plate 354 and the fixed column 352 are sealed and slidably connected, the gas in the fixed column 352 is sucked through the pipeline, forcing the sliding rod 356 to slide and shrink with the guard plate 357 into the fixed rod 355, thereby exposing the end of the ultrasonic probe 29. When the detection position changes, that is, the electric push rod 26 moves with the movable frame 25 through the push plate 27, so that the first magnetic block 351 is powered off, the second magnetic block 353 resets with the pressure plate 354, and the sliding rod 356 and the guard plate 357 are also reset. At this time, the ultrasonic probe 29 moves with the sliding frame 28, so the guard plate 357 will not hinder the ultrasonic probe 29 from performing detection. The moving sliding frame 28 will bring the pressure plates 354 on both sides to squeeze the first cavity 32 in the elastic block 31, so that the gas in the first cavity 32 is sprayed toward the end of the ultrasonic probe 29 through the jet pipe 34, thereby cleaning the ultrasonic probe 29 and reducing the influence of dust and impurities on its surface on the detection.

[0085] When the ultrasonic probe 29 detects a problem at a certain place of the air inlet pipe 10 or the air outlet pipe 13, the electric push rod 26 is started, and the electric push rod 26 is used to drive the sliding frame 28 and the pressing plate 354 to slide upward. When the pressing plate 354 moves to the loading box 41 with the first block, the first magnetic block 351 and the electromagnet 42 in the loading box 41 are energized, and the first magnetic block 351 will slide and squeeze the side plate 44 toward the loading box 41, so that the liquid used for marking in the loading box 41 is sprayed to the problematic part of the air inlet pipe 10 or the air outlet pipe 13 through the liquid guide tube 43. When the liquid enters the air guide tube, it will rotate to open the end cover 45, so that the end cover 45 and the limiting rod 48 are rotated and clamped into the limiting groove 49, and at the same time, the cover plate will squeeze the first elastic ball 46, so that the gas in the first elastic ball 46 enters the roll film 47 through the connecting tube, and quickly unfolds the roll film 47 inflation brush. When the marking liquid cannot be dried immediately after being sprayed, a small amount of the liquid will flow down. At this time, the rolled film 47 unfolded by the brush is used to catch the flowing liquid, thereby reducing the pollution and waste after the liquid flows down. When the liquid guide tube 43 is no longer used, the end cover 45 is no longer impacted, and rotates and resets under the action of the first elastic ball 46, and the gas in the rolled film 47 flows back into the first elastic ball 46. At the same time, the limiting rod 48 is separated from the limiting groove 49, and the end cover 45 is used to close the port of the liquid guide tube 43 to reduce the entry of impurities.

[0086] Before using the movable frame 25, the maintenance block 53 is first placed in the placement frame 52. At this time, one side of the maintenance block 53 does not contact the surface of the pipe. As the sliding frame 28 moves with the pressing block 33, the pressing block 33 squeezes the second cavity 51 of the elastic block 31, so that the gas in the second cavity 51 enters into the plurality of second elastic balls 54 through the air guide tube, so that the second elastic balls 54 are filled with gas and expand, thereby pushing the placement frame 52 and the maintenance block 53 to move away from the movable frame 25, so that the maintenance block 53 in the placement frame 52 fits with the surface of the pipe, thereby achieving coating maintenance for the pipe after long-term use.

[0087] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A nitrogen charging control device for an oil-immersed transformer, characterized in that: The invention comprises a high-pressure nitrogen cylinder (1) and a touch screen (18), wherein one end of the high-pressure nitrogen cylinder (1) is connected to a pressure reducing valve (2), one end of the pressure reducing valve (2) away from the high-pressure nitrogen cylinder (1) is equipped with a first quick connector (3), one end of the first quick connector (3) away from the pressure reducing valve (2) is connected to a first hose (4), one end of the first hose (4) away from the first quick connector (3) is equipped with an intake pipe (10) through a second quick connector (5), an intake pressure gauge (6), a proportional valve (7), a solenoid valve (8) and a first pressure gauge (9) are installed on the intake pipe (10), one end of the intake pipe (10) is equipped with an outlet pipe (13), one end of the outlet pipe (13) is equipped with a second hose (12) through a third quick connector (11), and one end of the second hose (12) is connected to the top of the oil tank through a fourth quick connector (16); The touch screen (18) is connected to a controller (19), the controller (19) is connected to a display light (15), an intake pressure gauge (6), a proportional valve (7), a solenoid valve (8) and a first pressure gauge (9) via a communication bus (17), the controller (19) is connected to a magnetic thermal resistor (14) via the communication bus (17), and the magnetic thermal resistor (14) is connected to a fuel tank; The air intake pipe (10) is provided with a detection mechanism (20) for detecting the pipeline.

2. The nitrogen charging control device for oil-immersed transformer according to claim 1 is characterized in that: The detection mechanism (20) comprises a connection frame (22) connected to the air intake pipe (10) via a collar (21), a servo motor (23) is installed inside the connection frame (22), a screw rod (24) is installed at the output end of the servo motor (23), one end of the screw rod (24) away from the servo motor (23) is connected to the connection frame (22), and a movable frame (25) is movably connected to the surface of the screw rod (24); An electric push rod (26) is fixedly installed in the movable frame (25), and a push plate (27) is fixedly installed at the output end of the electric push rod (26). An arc-shaped sliding frame (28) is slidably connected in the movable frame (25), and an ultrasonic probe (29) is fixedly installed in the sliding frame (28). The ultrasonic probe (29) is connected to the controller (19) and the touch screen (18) through a signal line.

3. The nitrogen charging control device for oil-immersed transformer according to claim 2 is characterized in that: The movable frame (25) is provided with an air blowing mechanism (30), the air blowing mechanism (30) comprising two elastic blocks (31) fixedly mounted in the movable frame (25), a first cavity (32) being provided at the bottom of the elastic blocks (31), pressing blocks (33) being fixedly mounted on both sides of the sliding frame (28), an air jet pipe (34) being fixedly mounted in the movable frame (25), an air outlet end of the air jet pipe (34) being aligned with the ultrasonic probe (29), and one end of the air jet pipe (34) being in communication with the first cavity (32); A protection component (35) is arranged in the movable frame (25).

4. The nitrogen charging control device for oil-immersed transformer according to claim 3 is characterized in that: The protective component (35) comprises a first magnetic block (351) arranged at one end of the pressure block (33); a hollow fixed column (352) is fixedly installed in the movable frame (25); a pressure plate (354) is sealed and slidably connected in the fixed column (352); a second magnetic block (353) is fixedly installed on one side of the pressure plate (354); a spring is fixedly installed between the second magnetic block (353) and the fixed column (352); the second magnetic block (353) is sealed and slidably connected to the fixed column (352); a hollow fixed rod (355) is fixedly installed on one side of the movable frame (25); the fixed rod (355) and the fixed column (352) are connected by a pipeline; a sliding rod (356) is sealed and slidably connected inside the fixed rod (355) through an elastic member; and a protective plate (357) is fixedly connected to one end of the sliding rod (356) away from the fixed rod (355).

5. The nitrogen charging control device for oil-immersed transformer according to claim 4 is characterized in that: The movable frame (25) contains a finger marking mechanism (40), the marking mechanism (40) comprises two loading boxes (41) fixedly mounted in the movable frame (25), the loading boxes (41) being made of hollow rubber material, a liquid guide tube (43) with a one-way valve fixedly mounted on one side of the loading box (41), the end of the liquid guide tube (43) away from the loading box (41) being aligned with the air inlet pipe (10), a liquid inlet pipe connected to the inside of the loading box (41) being mounted on one side of the loading box (41), an electromagnet (42) fixedly mounted in the loading box (41), the first magnetic block (351) being slidably connected via a spring and a pressure block (33).

6. The nitrogen charging control device for oil-immersed transformer according to claim 5, characterized in that: Two symmetrically arranged side plates (44) are fixedly mounted on one side of the first magnetic block (351), and the side plates (44) are arc-shaped.

7. The nitrogen charging control device for oil-immersed transformer according to claim 5, characterized in that: An end cap (45) is rotatably connected to the end of the liquid guiding tube (43), and a first elastic ball (46) is fixedly installed between the end cap (45) and the liquid guiding tube (43).

8. The nitrogen charging control device for oil-immersed transformer according to claim 7, characterized in that: A hollow rolled film (47) is fixedly mounted on the bottom of the liquid guiding tube (43), and the rolled film (47) and the first elastic ball (46) are connected via a connecting tube.

9. The nitrogen charging control device for oil-immersed transformer according to claim 8, characterized in that: A curved limiting rod (48) made of rubber material is fixedly mounted on one side of the end cover (45), and a limiting groove (49) matching the limiting rod (48) is provided in the liquid guiding tube (43).

10. The nitrogen charging control device for oil-immersed transformer according to claim 3, characterized in that: A maintenance mechanism (50) is arranged in the movable frame (25), and the maintenance mechanism (50) comprises a second cavity (51) in the elastic block (31). Two arc-shaped placement frames (52) are slidably connected in the sliding frame (28), and a maintenance block (53) is arranged in the placement frame (52). A plurality of second elastic balls (54) are fixedly installed between the placement frame (52) and the sliding frame (28), and the second elastic balls (54) and the second cavity (51) are connected via an air guide tube.

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