Improved device for monitoring the deformation of the walls of a transformer tank and the rate of vacuum leakage

Abstract

The utility model provides an improved device for monitoring transformer oil tank wall deformation and vacuum leakage rate belongs to transformer monitoring technical field. The utility model has carried out the deepening design to electric telescopic link and air extraction valve on the basis of original technical scheme. In the structure of electric telescopic link, the threaded rod is rotated by motor drive, makes the motion block on it drive the top column to do the feed movement, to realize telescopic action, compared with the original technology, this kind of movement mechanism is more stable, and the friction is smaller, has improved the stability and reliability of lifting movement. In the structure of air extraction valve, the cylinder is additionally arranged at the bottom end of the valve core, and the cylinder is kept in the sliding sleeve during the stroke of the valve core. Based on the cooperation relationship between the cylinder and the sliding sleeve, the radial movement of the bottom end of the valve core is avoided, and the valve core vibration is effectively relieved. The utility model makes the deformation measurement mechanism more stable during operation, and at the same time, the mechanical vibration problem of the valve core of the leakage rate monitoring mechanism during operation is relieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to transformer monitoring technical field especially relates to the improved device for monitoring transformer oil tank wall deformation and vacuum leakage rate. BACKGROUND

[0002] When the transformer is vacuumized, the industry specification stipulates that the maximum value of the oil tank deformation shall not exceed twice the maximum value of the wall thickness. When measuring the oil tank deformation by the traditional method, first, the measuring deformation amount of the standard pole is installed in the center of the oil tank top cover and the four corners of the tank wall in turn, then the height of the center point of the oil tank top cover and the center point of the tank wall is taken as the reference, the standard poles are connected by a line, and the distance between the line and the tank cover and the tank wall is measured by a steel ruler, and the relevant values are recorded as the initial data. After the oil tank is vacuumized and deformed, the distance between the line and the tank cover and the tank wall is measured again, and the deformation amount of the tank cover and the tank wall is calculated by comparing with the original data.

[0003] The above-mentioned method for measuring the deformation amount of the oil tank requires the assistance of multiple people to complete, and the efficiency is low and the precision is low. In addition, when the vacuum degree in the oil tank reaches below 200 Pa, the outlet valve of the vacuum unit needs to be closed to measure the system leakage rate, and the residual pressure P l is recorded after 5-10 minutes of static placement. After 30 minutes, the residual pressure P2 is recorded, and then the leakage rate (η) of the transformer is calculated according to the formula: η = (P2-P l ) × V ÷ t to evaluate whether the current leakage rate value meets the requirements of the product technical document. The foregoing detection of the leakage rate of the transformer is low in efficiency and time-consuming.

[0004] In view of the above defects, the applicant applied for a Chinese utility model patent application entitled "Novel Device for Monitoring Transformer Oil Tank Wall Deformation and Vacuum Leakage Rate" (Publication No. CN218329896U) on October 21, 2022, and was granted on January 17, 2023. This technical solution indeed solves the problems of requiring multiple people to assist in measurement, low efficiency and poor precision, but in the actual application in the past two years, it is found that there are still some defects: the electric telescopic rod used in this technical solution is built into two sections of square tubes that are inserted into each other, and the upper square tube is pushed to move vertically by the electric telescopic rod. Since there is a certain gap between the inner and outer square tubes, the stability is insufficient during the movement, and the friction between the inner and outer square tubes when they slide relative to each other further exacerbates this instability. In addition, the air extraction valve in this technical solution is of a conventional structure, which is easily impacted by airflow and causes vibration, which is not conducive to ensuring the stability and reliability of the valve operation. Based on these technical deficiencies, the device still needs to be further improved. SUMMARY

[0005] The utility model wants to solve the technical problem: the stability of the extension mechanism movement of the Chinese utility model patent technology with publication number CN218329896U needs to be improved, and the valve core is obviously vibrated by airflow in the use process.

[0006] To realize above technical purpose, the utility model adopts the following technical scheme:

[0007] The improved device for monitoring transformer oil tank wall deformation and vacuum leakage rate, including deformation measurement mechanism, it includes five groups of magnet suction disc fixedly adsorbed at the outer wall of transformer oil tank, fixedly connected on corresponding magnet suction disc rope, be used for traction corresponding electric telescopic rod, be located above transformer oil tank horizontal telescopic rod, be used for providing corresponding electric telescopic rod installation support support, be used for detecting corresponding displacement sensor of rope offset value; Fixedly installed on the vacuum valve and vacuum transmitter of transformer; And leakage rate monitoring mechanism, its input end is electrically connected with the output end of vacuum transmitter; One group of magnet suction disc is arranged at the center position of transformer oil tank top cover, and the remaining four groups of magnet suction disc are evenly arranged at the position of the tank wall around transformer oil tank; Electric telescopic rod includes base, top seat, threaded rod, moving block, motor, top column, sliding hole, backing plate, sheath, wherein threaded rod is rotatably connected between base and top seat, moving block is threadedly connected with threaded rod, motor is fixedly installed on base, motor is drivingly connected with threaded rod, a plurality of top columns are fixed on moving block, a plurality of sliding holes are formed in top seat, a plurality of top columns pass through a plurality of sliding holes and are connected with backing plate, and sheath is connected between the edge of base and the edge of top seat.

[0008] As preferred, the horizontal telescopic rod and the adjacent electric telescopic rod are combined into a concave structure, and the horizontal telescopic rod is fixedly connected with the corresponding electric telescopic rod.

[0009] As preferred, one group of displacement sensors is fixedly installed on the horizontal telescopic rod, and the remaining four groups of displacement sensors are fixedly installed on the corresponding electric telescopic rods.

[0010] As preferred, the leakage rate monitoring mechanism includes a vacuum unit, an air extraction valve and a control box fixedly installed on the vacuum unit, and a touch display screen fixedly installed on the control box; the control box is provided with a programmable controller PLC; the air extraction valve includes an inner cavity, a valve body, an exhaust passage, an air inlet passage, a valve rod, a handle, a valve core, an annular table, a column, a sliding sleeve, and pores; the valve rod is arranged on the valve body, the handle is connected to the outer side of the valve rod, the valve core is connected to the inner side of the valve rod, the valve body has an inner cavity, the side and lower part of the inner cavity are respectively the exhaust passage and the air inlet passage, the annular table is arranged in the air inlet passage, the valve core is matched with the annular table, the column is arranged at the bottom end of the valve core, the sliding sleeve is arranged on the inner wall of the air inlet passage, the column is inserted and matched with the sliding sleeve, and the pores are arranged on the side wall of the sliding sleeve.

[0011] As preferred, the vacuum unit is located at a corresponding side position of the transformer, and a gas pipe is communicated between the vacuum unit and the transformer through an air exhaust valve and a vacuumizing valve; the control box and the vacuum transmitter are electrically connected through a cable joint.

[0012] As preferred, the output ends of the electric telescopic rod, the horizontal telescopic rod and the displacement sensor are electrically connected with the input end of the control box.

[0013] In the above technical scheme, the electric telescopic rod and the air exhaust valve are optimized. In the structure of the electric telescopic rod, the threaded rod between the base and the top base is driven to rotate by the motor, and based on the threaded connection relationship between the threaded rod and the moving block, the moving block is driven to feed along the threaded rod with the rotation of the threaded rod, and the top column on the moving block pushes the supporting plate to extend or retract, so as to realize the telescopic movement. Compared with the original technology, the movement mechanism is more stable and has smaller friction, and the stability and reliability of the lifting movement are improved. In the structure of the air exhaust valve, the valve core and the annular table form a sealing surface, and the opening or locking of the valve is realized by the clutch of the two, and in this stroke process, the column at the bottom of the valve core is kept in the sliding sleeve, and since the column and the sliding sleeve are in sliding fit, the column at the bottom of the valve core is stabilized, and the vibration of the valve core is effectively relieved. Compared with the original technology, the deformation measurement mechanism is more stable in operation, and the mechanical vibration problem of the valve core of the leakage rate monitoring mechanism in operation is relieved, and has significant technical advantages. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is the perspective view of the deformation measurement mechanism in the utility model;

[0015] Figure 2 is the schematic view of the leakage rate monitoring mechanism in the utility model;

[0016] Figure 3 is the perspective view of the electric telescopic rod in the utility model;

[0017] Figure 4 is the perspective view of the part of the electric telescopic rod in the utility model except the sheath;

[0018] Figure 5 is the perspective view of the part of the electric telescopic rod in the utility model except the sheath in the cut state;

[0019] Figure 6 is the sectional view of the air exhaust valve in the utility model;

[0020] Figure 7 is the top view of the air exhaust valve in the utility model;

[0021] Figure 8 yes Figure 6 A magnified view of position A in the middle;

[0022] In the picture:

[0023] 1. Deformation measurement mechanism; 11. Magnetic suction cup; 12. Pull rope; 13. Electric telescopic rod; 14. Horizontal telescopic rod; 15. Support; 16. Displacement sensor; 2. Vacuum valve; 3. Vacuum transmitter; 4. Leakage rate monitoring mechanism; 41. Vacuum unit; 42. Evacuation valve; 43. Control box; 44. Touch screen; 101. Base; 102. Top seat; 103. Threaded rod; 104. Moving block; 105. Motor; 106. Top column; 107. Sliding hole; 108. Support plate; 109. Sheath; 201. Inner cavity; 202. Valve body; 203. Exhaust channel; 204. Inlet channel; 205. Valve stem; 206. Handle; 207. Valve core; 208. Annular platform; 209. Column; 210. Sliding sleeve; 211. Orifice. Detailed Implementation

[0024] The specific embodiments of this utility model will be described in detail below. To avoid excessive and unnecessary details, well-known structures or functions will not be described in detail in the following embodiments. The approximate language used in the following embodiments can be used for quantitative descriptions, indicating that a certain degree of variation in quantity is permissible without changing the basic function. Unless otherwise defined, the technical and scientific terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art to which this utility model pertains.

[0025] An improved device for monitoring transformer tank wall deformation and vacuum leakage rate includes a deformation measuring mechanism 1, such as... Figure 1 As shown, it includes five sets of magnetic suction cups 11 fixed to the outer wall of the transformer tank, pull ropes 12 fixedly connected to the corresponding magnetic suction cups 11, electric telescopic rods 13 for pulling the corresponding pull ropes 12, a horizontal telescopic rod 14 located above the transformer tank, a support 15 for providing mounting support for the corresponding electric telescopic rods 13, and a displacement sensor 16 for detecting the offset value of the corresponding pull ropes 12; a vacuum valve 2 and a vacuum transmitter 3 fixedly installed on the transformer; and a leakage rate monitoring mechanism 4, the input end of which is electrically connected to the output end of the vacuum transmitter 3; one set of the magnetic suction cups 11 is arranged at the center of the transformer tank top cover, and the remaining four sets of the magnetic suction cups 11 are evenly arranged around the perimeter of the transformer tank wall; as shown Figures 3-5As shown, the electric telescopic rod 13 comprises a base 101, a top base 102, a threaded rod 103, a moving block 104, a motor 105, top columns 106, sliding holes 107, a supporting plate 108, a sheath 109, wherein the threaded rod 103 is rotatably connected between the base 101 and the top base 102, the moving block 104 is threadedly connected with the threaded rod 103, the motor 105 is fixedly installed on the base 101 and is in transmission connection with the threaded rod 103, the top columns 106 are fixed on the moving block 104, the sliding holes 107 are arranged on the top base 102, the top columns 106 penetrate through the sliding holes 107 and are connected with the supporting plate 108, and the sheath 109 is connected between the edge of the base 101 and the edge of the top base 102.

[0026] The horizontal telescopic rod 14 and the adjacent electric telescopic rod 13 are combined into a concave structure, and the horizontal telescopic rod 14 is fixedly connected with the corresponding electric telescopic rod 13.

[0027] One group of the displacement sensors 16 is fixedly installed on the horizontal telescopic rod 14, and the remaining four groups of the displacement sensors 16 are fixedly installed on the corresponding electric telescopic rod 13.

[0028] As shown in the figure, Figure 2 As shown, the leakage rate monitoring mechanism 4 comprises a vacuum unit 41, an air extraction valve 42 and a control box 43 fixedly installed on the vacuum unit 41, and a touch display screen 44 fixedly installed on the control box 43; the control box 43 is provided with a programmable controller PLC; as shown in the figure, Figures 6-8 As shown, the air extraction valve 42 comprises an inner cavity 201, a valve body 202, an exhaust passage 203, an air inlet passage 204, a valve rod 205, a handle 206, a valve core 207, an annular table 208, a column body 209, a sliding sleeve 210, and a plurality of apertures 211, wherein the valve rod 205 is arranged on the valve body 202, the handle 206 is connected to the outer side of the valve rod 205, the valve core 207 is connected to the inner side of the valve rod 205, the inner cavity 201 is arranged in the valve body 202, the side portion and the lower portion of the inner cavity 201 are respectively the exhaust passage 203 and the air inlet passage 204, the annular table 208 is arranged in the air inlet passage 204, the valve core 207 cooperates with the annular table 208, the column body 209 is arranged at the bottom end of the valve core 207, the sliding sleeve 210 is arranged on the inner wall of the air inlet passage 204, the column body 209 is in plug-in cooperation with the sliding sleeve 210, and the plurality of apertures 211 are arranged on the side wall of the sliding sleeve 210.

[0029] The vacuum unit 41 is located at a corresponding side position of the transformer, and the vacuum unit 41 and the transformer are in communication with an air pipe through the air extraction valve 42 and the vacuum extraction valve 2; the control box 43 and the vacuum transmitter 3 are electrically connected through a cable joint.

[0030] The output ends of the electric telescopic rod 13, the horizontal telescopic rod 14 and the displacement sensor 16 are electrically connected with the input end of the control box 43.

[0031] For the measurement function, use method, operation principle and other technical contents of the utility model, the new device for monitoring the deformation and vacuum leakage rate of the transformer oil tank wall (publication number CN218329896U) can be implemented, and no further expansion is needed.

[0032] The electric telescopic rod 13 and the air extraction valve 42 are further designed in the embodiment. In the structure of the electric telescopic rod 13, the threaded rod 103 between the base 101 and the top base 102 is driven to rotate by the motor 105, and based on the threaded connection relationship between the threaded rod 103 and the moving block 104, the moving block 104 is driven to feed along the threaded rod 103 with the rotation of the threaded rod 103, and the top column 106 on the moving block 104 pushes the supporting plate 108 to extend or retract, so as to realize the telescopic movement. Compared with the original technology, the movement mechanism is more stable, the friction is smaller, and the stability and reliability of the lifting movement are improved. In the structure of the air extraction valve 42, the valve core 207 and the annular table 208 form a sealing surface, and the opening or locking of the valve is realized by the clutch of the two. During the stroke, the cylinder 209 at the bottom of the valve core 207 is kept in the sliding sleeve 210. Since the cylinder 209 is in sliding fit with the sliding sleeve 210, the cylinder 209 plays a stabilizing role at the bottom end of the valve core 207, effectively alleviating the vibration of the valve core 207. Compared with the original technology, the utility model makes the deformation measurement mechanism 1 more stable in operation, and at the same time, the mechanical vibration problem of the valve core 207 in the operation of the leakage rate monitoring mechanism 4 is alleviated, which has significant technical advantages.

[0033] In addition, the utility model patent technology with the publication number CN218329896U can only play a monitoring role, and cannot automatically take intervention measures for the deformation exceeding the standard. In view of this problem, the embodiment can additionally add an air control valve, so as to monitor and protect the deformation of the oil tank wall.

[0034] The main function of the air control valve is to accurately adjust the vacuum degree of the transformer, so as to ensure that the deformation of the oil tank does not exceed twice the maximum value of the wall thickness. The device can be controlled by PLC or manual I / O. In the open state of the air control valve, it will suck in air, so as to prevent the steel plate of the transformer oil tank from further deforming, and realize the automatic protection function. That is, when the system detects that the deformation of the transformer oil tank is higher than the preset value, the air control valve will be opened, and the air will be sucked in, so as to appropriately reduce the vacuum degree in the cavity of the transformer, ensure that the deformation of the oil tank wall does not exceed the standard, and ensure the safety of the transformer body. This design effectively avoids the safety hazard caused by excessive deformation of the oil tank wall. The air control valve can be selected from commercially available conventional models, such as a vacuum electromagnetic air control valve (2Q200-15).

[0035] The core function of this improvement is to ensure that the maximum deformation of the transformer tank does not exceed twice the maximum wall thickness during the transformer tank wall deformation monitoring process. The system is mainly composed of a fixed bracket base, a strong magnet suction cup, an electric telescopic rod, a horizontal telescopic rod, a pull rope displacement sensor (data logger), a pull rope, a pull rope magnet suction cup, an electric air valve, an air control valve, a pressure transmitter, a vacuum machine, and a PLC control module, which work together to achieve the automatic protection function of the tank deformation.

[0036] During the transformer tank wall deformation monitoring process, the pull rope displacement sensor continuously monitors the deformation data of the transformer tank wall steel plate and feeds back the real-time deformation data to the PLC control module. When the system detects that the tank wall deformation is greater than the preset threshold, the PLC control module will immediately instruct the electric air control valve to open, appropriately reducing the vacuum degree in the transformer cavity to avoid further deformation of the tank wall.

[0037] During the entire tank wall deformation monitoring process, the PLC control module continuously monitors the changes of the tank wall and adjusts the electric air valve and air control valve in real time according to the actual situation, ensuring that the deformation of the transformer tank wall does not exceed twice the maximum wall thickness. This automatic control method not only improves the response speed of the system, but also reduces the need for human intervention, thereby improving the stability and safety of the transformer operation.

[0038] In addition, the system also has a fault alarm function. When the system detects any abnormal situation or fault, it will immediately trigger the alarm mechanism to notify the maintenance personnel for processing. This helps to discover and solve potential problems in a timely manner, ensuring the normal operation of the transformer.

[0039] To achieve this protection function, the PLC module needs to be adapted as follows: In the programmable logic controller (PLC), the calculation formula for leak detection is programmed, and combined with the key parameters such as the weight, density, deduction time, and test time of the transformer insulation oil during maintenance, the real-time monitoring of the transformer vacuum leakage rate can be realized. The calculation formula for transformer vacuum leakage rate detection is: η = (P2 - P l ) × V ÷ t, where η represents the leakage rate (unit: less than 1000 Pa.L / s); after closing the air valve, it needs to be maintained in a closed state for 10 min, and then the first measured pressure value P l is recorded (unit: Pa); then the second pressure value P2 (unit: Pa) is recorded; V represents the volume of the transformer oil (unit: L); M represents the oil quantity of the transformer (unit: M); ρ represents the density of the transformer oil, with a unit of kilograms per liter (kg / L), which can be taken as 0.9 kg / L, so V = M ÷ ρ; t represents the time interval between the two pressure recordings (unit: s).

[0040] After the technical improvement, the device can not only monitor the deformation of the oil tank wall in real time, but also take measures automatically to protect when the deformation exceeds the preset threshold, effectively avoiding the safety hazards caused by excessive deformation of the oil tank wall. This design not only improves the operation safety of the transformer, but also prolongs the service life of the transformer.

[0041] The above describes the embodiments of the utility model in detail, but the content is only the preferred embodiment of the utility model, and does not limit the utility model. Any modification, equivalent replacement and improvement made within the application range of the utility model should be included in the protection range of the utility model.

Claims

1. An improved device for monitoring the deformation of the wall of a transformer oil tank and the rate of vacuum leakage, comprising a deformation measuring mechanism (1) comprising five groups of magnet suction cups (11) fixedly attached to the outer wall of the transformer oil tank, pull ropes (12) fixedly connected to the corresponding magnet suction cups (11), electric telescopic rods (13) for pulling the corresponding pull ropes (12), horizontal telescopic rods (14) located above the transformer oil tank, supports (15) for providing mounting support for the corresponding electric telescopic rods (13), displacement sensors (16) for detecting the displacement value of the corresponding pull ropes (12); a vacuum extraction valve (2) and a vacuum transmitter (3) fixedly installed on the transformer; and a leakage rate detection mechanism (4) having an input end electrically connected to the output end of the vacuum transmitter (3); wherein one group of the magnet suction cups (11) is arranged at the center of the top cover of the transformer oil tank, and the remaining four groups of the magnet suction cups (11) are uniformly arranged at the positions around the wall of the transformer oil tank; characterized in that, The electric telescopic rod (13) comprises a base (101), a top base (102), a threaded rod (103), a moving block (104), a motor (105), top columns (106), sliding holes (107), a supporting plate (108), a sheath (109), wherein the threaded rod (103) is rotationally connected between the base (101) and the top base (102), the moving block (104) is threadedly connected with the threaded rod (103), the motor (105) is fixedly installed on the base (101) and is in transmission connection with the threaded rod (103), a plurality of top columns (106) are fixed on the moving block (104), a plurality of sliding holes (107) are formed in the top base (102), the plurality of top columns (106) penetrate through the plurality of sliding holes (107) and are connected with the supporting plate (108), and the sheath (109) is connected between the edge of the base (101) and the edge of the top base (102).

2. The improved device for monitoring the deformation of the transformer tank wall and the vacuum leakage rate according to claim 1, characterized in that, The horizontal telescopic rod (14) and the adjacent electric telescopic rod (13) are combined into a concave structure, and the horizontal telescopic rod (14) is fixedly connected with the corresponding electric telescopic rod (13).

3. The improved device for monitoring the deformation of the transformer tank wall and the vacuum leakage rate according to claim 1, characterized in that, One group of the displacement sensors (16) is fixedly installed on the horizontal telescopic rod (14), and the remaining four groups of the displacement sensors (16) are fixedly installed on the corresponding electric telescopic rod (13).

4. The improved device for monitoring the deformation of the transformer tank wall and the vacuum leakage rate according to claim 1, characterized in that, The leakage rate detection mechanism (4) comprises a vacuum unit (41), an air extraction valve (42) and a control box (43) fixedly installed on the vacuum unit (41), and a touch display screen (44) fixedly installed on the control box (43); the control box (43) is provided with a programmable controller PLC; the air extraction valve (42) comprises an inner cavity (201), a valve body (202), an exhaust passage (203), an air inlet passage (204), a valve rod (205), a handle (206), a valve core (207), an annular table (208), a column (209), a sliding sleeve (210), and a pore (211); the valve rod (205) is arranged on the valve body (202), the handle (206) is connected to the outer side of the valve rod (205), the valve core (207) is connected to the inner side of the valve rod (205), the inner cavity (201) is arranged in the valve body (202), the side and lower part of the inner cavity (201) are respectively the exhaust passage (203) and the air inlet passage (204), the annular table (208) is arranged in the air inlet passage (204), the valve core (207) is matched with the annular table (208), the column (209) is arranged at the bottom end of the valve core (207), the sliding sleeve (210) is arranged on the inner wall of the air inlet passage (204), the column (209) is in plug-in cooperation with the sliding sleeve (210), and the plurality of pores (211) are arranged on the side wall of the sliding sleeve (210).

5. The improved device for monitoring the deformation of the transformer tank wall and the vacuum leakage rate according to claim 4, characterized in that, The vacuum unit (41) is located at a corresponding side position of the transformer, and the vacuum unit (41) and the transformer are in communication through the air extraction valve (42) and the vacuum extraction valve (2); the control box (43) and the vacuum transmitter (3) are electrically connected through a cable joint.

6. The improved device for monitoring the deformation of the transformer tank wall and the vacuum leakage rate according to claim 4, characterized in that, The output ends of the electric telescopic rod (13), the horizontal telescopic rod (14) and the displacement sensor (16) are electrically connected with the input end of the control box (43).

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