A method for online treatment of transformer oil leakage and a sealing and fastening structure

Abstract

This application provides an online method for treating transformer oil leakage and a sealing and fastening structure, belonging to the field of online transformer maintenance technology. The method includes: without shutting down the power supply to replace the original O-ring seals, a rubber ring is added to the fixing bolts of the flange cover plate to seal the outside of the flange cover plate, thereby preventing insulating oil leakage at the fixing bolts; without disassembling the fixing bolts, the transformer can be maintained online without shutting down the power supply, eliminating the need for generator load reduction and shutdown, avoiding a sudden increase in power load when the power supply is restored, thus reducing the maximum demand value, ensuring the continuity of equipment operation and the stability of power supply, avoiding new load peaks, avoiding production interruption losses caused by power outages for maintenance, and increasing economic benefits; simultaneously, when treating transformer oil leakage online, the generator set can continue to generate electricity while operating normally, consuming all the gas, avoiding the release of gas generated during transformer power outage maintenance, reducing resource waste and environmental pollution.

Description

Technical Field

[0001] This application belongs to the field of transformer online maintenance technology, specifically relating to an online treatment method for transformer oil leakage and a sealing and fastening structure. Background Technology

[0002] After long-term operation, high-voltage plant service transformers may develop multiple oil leakage points, requiring regular maintenance. However, even after maintenance and a period of operation, it is still unavoidable to experience persistent slight oil leakage from the secondary lead flange of the A-phase current transformer on the high-voltage side. If not addressed promptly, the oil level in the high-voltage plant service transformer will gradually decrease. When the oil level falls below the transformer's burn-out level, a short-circuit accident will occur, causing severe economic losses.

[0003] Currently, there are two solutions to the oil leakage problem at the secondary lead-out flange of the A-phase current transformer on the high-voltage side of the transformer. One solution is to seal the oil leakage point by applying sealant or silicone sealant to ensure the normal operation of the transformer. However, after three months of operation, the oil level in the oil tank still drops significantly, failing to fundamentally solve the oil leakage problem. The second solution is to shut down the unit, replace the O-ring seal on the flange, and after replacing the seal, check the oil level to confirm that there is no more oil leakage. Then, let the transformer stand for 24 hours, take an oil sample for an oil withstand voltage test, and restore power after passing the test. The entire process involves the transformer being shut down for at least 30 hours, during which time the generator cannot be started and generate electricity, resulting in significant economic losses. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] Therefore, the first aspect of the present invention provides an online method for treating transformer oil leakage.

[0006] A second aspect of the present invention provides a sealing and fastening structure for transformer oil leakage.

[0007] In view of this, a method for online treatment of transformer oil leakage is proposed according to a first aspect of the embodiments of this application, comprising:

[0008] Add oil to the oil tank until the oil level in the oil tank is not lower than the first oil level;

[0009] Release the gas from the gas relay until oil flows out of the gas relay without any air bubbles, then stop releasing the gas.

[0010] Rubber rings were installed on the outside of the fixing bolts of the flange cover plate of the secondary lead of the A-phase current transformer on the high-voltage side of the transformer to seal the outside of the flange cover plate.

[0011] In one feasible implementation, oil is injected into the oil tank until the oil level in the oil tank is not lower than the first oil level, including the following steps:

[0012] Remove the screws inside the vent hole of the oil tank and loosen the main oil tank breather;

[0013] Inspect the oil filter and install the oil filling pipe on the oil tank;

[0014] Open the valve on the refueling hose and inject fuel into the fuel tank from below through the refueling hose;

[0015] When filling with oil, pay attention to the venting of the air vent.

[0016] Stop adding oil when the oil level gauge shows the first oil level.

[0017] Close the valve on the refueling hose and disconnect the refueling hose from the fuel tank;

[0018] Reinstall the vent screws and tighten the main fuel tank breather.

[0019] In one feasible implementation, the first oil level is the seventh cell on the oil level gauge.

[0020] In one feasible implementation, rubber rings are sequentially installed on the outside of the fixing bolts of the flange cover plate of the secondary lead of the A-phase current transformer on the high-voltage side of the transformer to seal the outside of the flange cover plate, including the following steps:

[0021] Remove the nuts, spring plates, and steel washers from the fixing bolts;

[0022] Install rubber rings on the fixing bolts;

[0023] Install the nut back onto the fixing bolt, and use the nut and flange cover to press the rubber ring, causing the rubber ring to deform.

[0024] Repeat the above steps until rubber rings are installed on all the fixing bolts.

[0025] In one feasible implementation, the rubber ring is a flat nitrile rubber ring;

[0026] The inner diameter of the rubber ring is equal to the diameter of the fixing bolt, the outer diameter of the rubber ring is 1.5 to 2 times the diameter of the fixing bolt, and the thickness of the rubber ring is 0.15 to 0.25 times the diameter of the fixing bolt.

[0027] In one feasible implementation, the oil leak repair work is carried out on a temporary maintenance platform, which is set up close to the oil tank. The temporary maintenance platform is bounded by the edge of the oil tank, and during the operation, the workers and tools must not cross the boundary.

[0028] In one feasible implementation, before filling the oil tank with oil until the oil level in the oil tank is not lower than the first oil level, the following step is included:

[0029] Processing electrical maintenance work permits (Type II), work at height permits, and safety briefing sheets;

[0030] The equipment room, operation, inspection, and maintenance teams jointly confirmed the removal of the heavy gas protection interlock pressure plate.

[0031] Conduct a safety inspection of the temporary maintenance platform to confirm that it meets the operational requirements.

[0032] In one feasible implementation, after oil is injected into the oil tank, the transformer is run for a first period of time, during which patrols and inspections are strengthened. Every second period of time, the transformer's operating status is checked according to the patrol and inspection requirements. During the shift, attention is paid to whether there are any light gas alarm messages in the electrical monitoring background. When any abnormal situation occurs, it is reported in a timely manner and technical personnel are notified to go to the site for judgment and handling.

[0033] In one feasible implementation, after the first operating time is completed, the maintenance and inspection work area will process a second type of work ticket, a high-altitude operation ticket, and a safety briefing sheet. After the equipment room, operation, inspection, and maintenance personnel jointly confirm that the gas relay is free of oil bubbles and the heavy gas protection interlocking pressure plate is not activated, the operation personnel will apply to restore the heavy gas protection interlocking pressure plate to work.

[0034] According to a second aspect of the embodiments of this application, a sealing and fastening structure for transformer oil leakage is provided, which is applied to the online treatment method for transformer oil leakage as described in any of the above technical solutions. The sealing and fastening structure includes:

[0035] The fixing bolts pass through the flange and the flange cover plate in sequence.

[0036] The rubber ring is fitted onto the outside of the fixing bolt, and the rubber ring fits against the side of the flange face plate away from the flange.

[0037] The nut is fitted onto the fixing bolt, and the nut and fixing bolt are threaded together. The nut presses the rubber ring tightly and fixes it to the side of the flange cover plate away from the flange.

[0038] The online treatment method and sealing and fastening structure for transformer oil leakage disclosed in this application have the following advantages compared with the prior art:

[0039] Add oil to the oil conservator until the oil level is not lower than the first oil level to prevent rapid leakage of insulating oil at the corresponding fixing bolts when installing the O-rings, thus ensuring that the high-voltage station service transformer will not operate without oil during oil leakage maintenance; vent the gas relay to remove air bubbles, ensuring the reliability of gas protection operation, avoiding false alarms or tripping, and ensuring the safety of subsequent O-ring installation operations; when replacing the original O-rings without shutting down the system, install O-rings on the fixing bolts of the flange cover plate to seal the outside of the flange cover plate, thereby preventing insulating oil leakage at the fixing bolts; install O-rings on each fixing bolt in turn to ensure that when installing an O-ring on a single fixing bolt, its... The remaining fixing bolts maintain the stability of the flange and flange cover plate, thus ensuring the transformer can operate normally during oil leakage repairs. Without disassembling the fixing bolts, the transformer can be maintained online without shutting down the generator set, avoiding a sudden increase in power load upon recovery, thereby reducing the maximum demand value, ensuring the continuity of equipment operation and the stability of power supply, preventing new load spikes, avoiding production interruptions caused by maintenance shutdowns, and increasing economic benefits. Simultaneously, when dealing with transformer oil leakage online, the generator set can continue generating electricity after consuming all the gas, avoiding the release of gas generated during transformer power outages for maintenance, reducing resource waste and environmental pollution. Attached Figure Description

[0040] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0041] Figure 1 A schematic flowchart illustrating the steps of an online transformer oil leakage treatment method according to an embodiment of this application;

[0042] Figure 2 A schematic structural diagram of a transformer oil leakage sealing and fastening structure according to an embodiment of this application;

[0043] Figure 3 This is a schematic structural diagram of the original sealing structure at the transformer flange.

[0044] in, Figure 2 and Figure 3 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0045] 11. Fixing bolts; 12. Rubber rings; 13. Nuts; 14. Flange faceplate; 15. Flange; 16. O-ring seal. Detailed Implementation

[0046] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0048] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0049] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0050] like Figure 1 As shown, according to a first aspect of the embodiments of this application, an online method for treating transformer oil leakage is proposed, comprising:

[0051] Step 100: Add oil to the oil tank until the oil level in the oil tank is not lower than the first oil level;

[0052] Step 200: Release the gas from the gas relay until oil flows out of the gas relay without any air bubbles, then stop releasing the gas.

[0053] Step 300: Install rubber rings 12 on the outside of the fixing bolts 11 of the secondary lead flange cover plate 14 of the high-voltage side A-phase current transformer in sequence to seal the outside of the flange cover plate 14.

[0054] The online oil leakage treatment method for transformers provided in this application embodiment involves injecting oil into the oil tank until the oil level is not lower than the first oil level to prevent rapid leakage of insulating oil at the corresponding fixing bolts 11 when installing the rubber ring 12, thereby ensuring that the high-voltage station service transformer will not operate without oil during oil leakage maintenance; venting the gas relay to remove air bubbles ensures the reliability of gas protection operation, avoids false alarms or tripping, and guarantees the safety of subsequent rubber ring 12 installation operations; when replacing the original O-ring seal 16 without shutting down the machine, rubber rings 12 are installed on the fixing bolts 11 of the flange cover plate 14 to seal the outside of the flange cover plate 14, thereby preventing insulating oil leakage at the fixing bolts 11; and rubber rings 12 are installed on each fixing bolt 11 in turn. This ensures that when a single fixing bolt 11 is fitted with a rubber ring 12, the remaining fixing bolts 11 can maintain the stability of fixing the flange 15 and flange cover plate 14, thereby ensuring that the transformer can operate normally during oil leakage maintenance. Without disassembling the fixing bolts 11, the transformer can be maintained online without shutting down, without the need for the generator set to reduce load or stop, avoiding a sudden increase in power load when the shutdown is restored, thereby reducing the maximum demand value, ensuring the continuity of equipment operation and the stability of power supply, avoiding new load peaks, avoiding production interruption losses caused by shutdown maintenance, and increasing economic benefits. At the same time, when dealing with transformer oil leakage problems online, the generator set can continue to generate electricity after consuming all the gas during normal operation, avoiding the release of gas generated by transformer power outage maintenance, reducing resource waste and environmental pollution.

[0055] It should be noted that, as Figure 2 and Figure 3 As shown, the leakage point is located at the bottom fixing bolt 11 of the flange cover plate 14 of the secondary lead of the A-phase current transformer on the high-voltage side of the transformer. The O-ring seal 16 is set between the flange 15 and the flange cover plate 14. When replacing the O-ring seal 16, all fixing bolts 11 need to be removed, the flange cover plate 14 needs to be removed, and then the fixing bolts 11 and the flange cover plate 14 need to be reinstalled. However, by adding a rubber ring 12 to the fixing bolts 11 to seal the leakage point, it is not necessary to disassemble the fixing bolts 11 and the flange cover plate 14. On the basis of repairing the leakage point without stopping the machine, the maintenance time is further shortened, ensuring the continuity of transformer operation.

[0056] In one feasible implementation, oil is injected into the oil tank until the oil level in the oil tank is not lower than the first oil level, including the following steps:

[0057] Remove the screws inside the vent hole of the oil tank and loosen the main oil tank breather;

[0058] Inspect the oil filter and install the oil filling pipe on the oil tank;

[0059] Open the valve on the refueling hose and inject fuel into the fuel tank from below through the refueling hose;

[0060] When filling with oil, pay attention to the venting of the air vent.

[0061] Stop adding oil when the oil level gauge shows the first oil level.

[0062] Close the valve on the refueling hose and disconnect the refueling hose from the fuel tank;

[0063] Reinstall the vent screws and tighten the main fuel tank breather.

[0064] In this technical solution, the vent screws on the oil conservator are removed to release the internal air pressure, preventing sudden pressure changes during oil filling. The breather is loosened to balance the internal and external air pressure of the oil conservator, ensuring smooth oil injection and maintaining stable pressure during the filling process, preventing deformation or seal damage to the oil conservator. The oil filter is inspected to confirm the insulation strength of the new oil, ensuring the purity of the oil after filling. After installing the filling pipe and opening its valve, insulating oil is injected from below the oil conservator to prevent the oil flow from impacting and depositing impurities, making the filling speed controllable and reducing air bubble formation. The oil is monitored during the filling process. Check the oil level and venting status to ensure smooth gas discharge and prevent gas accumulation. Stop oiling once the first oil level is reached, leaving a buffer space for oil pressure to prevent oil overflow from the breather due to excessive oil level. This space also provides compensation to accommodate pressure changes inside the oil tank when adding the rubber ring 12 later. After oiling, close the valve on the oil filling pipe and remove the oil filling pipe to cut off the oil circuit and prevent backflow and leakage of insulating oil in the oil tank, ensuring stable performance of the insulating oil. Finally, reinstall the screw on the vent hole, tighten the breather, restore the oil tank seal, and prevent air from entering and causing oxidation and deterioration of the insulating oil.

[0065] In one feasible implementation, the first oil level is the seventh cell on the oil level gauge.

[0066] In this technical solution, after reserving sufficient oil pressure buffer space, the oil volume in the oil tank is filled to the maximum to avoid aggravating the oil leakage caused by uneven force on the flange cover plate 14 during the process of installing the rubber ring 12 on the fixing bolt 11 in sequence, thereby ensuring that the transformer does not run without oil when dealing with oil leakage points online.

[0067] In one feasible implementation, rubber rings 12 are sequentially installed on the outside of the fixing bolts 11 of the secondary lead flange cover plate 14 of the high-voltage side A-phase current transformer of the transformer to seal the outside of the flange cover plate 14, including the following steps:

[0068] Remove the nut 13, spring plate, and steel washer from the fixing bolt 11;

[0069] Fit the rubber ring 12 onto the fixing bolt 11;

[0070] Install the nut 13 back onto the fixing bolt 11, and use the nut 13 and the flange cover plate 14 to press the rubber ring 12, causing the rubber ring 12 to deform.

[0071] Repeat the above steps until rubber rings 12 are installed on all the fixing bolts 11.

[0072] In this technical solution, when adding the rubber ring 12, first remove the nut 13, spring plate, and steel washer from one fixing bolt 11, then install the rubber ring 12, reinstall the nut 13, and replace the original spring plate and steel washer structure with the rubber ring 12, thereby blocking oil leakage from the outside of the flange cover plate 14. Then, install the rubber ring 12 on the remaining fixing bolts 11 in sequence. By installing the rubber ring 12 on all fixing bolts 11, it is ensured that the flange cover plate 14 does not tilt after oil leakage maintenance, and the flange cover plate 14 is subjected to uniform force, thereby ensuring that there is no oil leakage at the fixing bolts 11 other than the bottom fixing bolt 11 of the flange cover plate 14.

[0073] In one feasible implementation, the rubber ring 12 is a flat nitrile rubber ring; the inner diameter of the rubber ring 12 is equal to the diameter of the fixing bolt 11, the outer diameter of the rubber ring 12 is 1.5 to 2 times the diameter of the fixing bolt 11, and the thickness of the rubber ring 12 is 0.15 to 0.25 times the diameter of the fixing bolt 11.

[0074] In this technical solution, a flat nitrile rubber ring is used as the sealing structure of the flange cover plate 14 to ensure full contact between the flange cover plate 14 and the rubber ring 12. The soft rubber surface of the rubber ring 12 is used to seal the oil leakage at the lowest fixing bolt 11 on the flange 15 of the secondary lead of the A-phase current transformer outside the flange cover plate 14. By making the inner diameter of the rubber ring 12 equal to the diameter of the fixing bolt 11, the outer diameter of the rubber ring 12 1.5 to 2 times the diameter of the fixing bolt 11, and the thickness of the rubber ring 12 0.15 to 0.25 times the diameter of the fixing bolt 11, the rubber ring 12 has sufficient elastic deformation capacity, ensuring the fit between the inner ring of the rubber ring 12 and the fixing bolt 11, and preventing the outer ring of the rubber ring 12 from being exposed, thus avoiding aging of the rubber ring 12, extending the service life of the rubber ring 12, and ensuring the sealing effect of the rubber ring 12 at the original oil leakage point.

[0075] In one feasible implementation, the oil leak repair work is carried out on a temporary maintenance platform, which is set up close to the oil tank. The temporary maintenance platform is bounded by the edge of the oil tank, and during the operation, the workers and tools must not cross the boundary.

[0076] In this technical solution, a temporary maintenance platform is erected near the oil tank to handle oil leaks. The edge of the oil tank serves as the boundary, which reduces the distance personnel need to move and shortens the time required to handle the leak. The boundary also clearly defines the work area, preventing personnel or tools from accidentally touching live equipment and reducing the risk of electric shock. At the same time, it avoids interference caused by adjusting the position outside the boundary during the operation, thus ensuring the accuracy of the operation.

[0077] In one feasible implementation, before filling the oil tank with oil until the oil level in the oil tank is not lower than the first oil level, the following step is included:

[0078] Processing electrical maintenance work permits (Type II), work at height permits, and safety briefing sheets;

[0079] The equipment room, operation, inspection, and maintenance teams jointly confirmed the removal of the heavy gas protection interlock pressure plate.

[0080] Conduct a safety inspection of the temporary maintenance platform to confirm that it meets the operational requirements.

[0081] In this technical solution, a second type of work permit for electrical maintenance, a work permit for working at height, and a safety briefing form are processed, and the safety responsibilities of all parties are clearly defined through standardized procedures. The equipment room, operation, inspection, and maintenance parties jointly confirm the removal of the heavy gas protection interlocking pressure plate to prevent oil flow disturbance during oil injection or maintenance from causing the gas protection to trip erroneously. Multiple departments jointly confirm the pressure plate's removal status to avoid unilateral oversight and ensure that the transformer's heavy gas protection switches from "trip" to "signal" mode, maintaining fault monitoring functions while preventing unplanned shutdowns caused by malfunctions. A safety inspection is conducted on the temporary maintenance platform to confirm that it meets the work requirements, eliminating structural risks in the high-altitude work environment. The stability of the platform's support structure and the safe distance from live equipment are checked to prevent falls due to insufficient load-bearing capacity or slippage. The boundary of the temporary maintenance platform is confirmed to be aligned with the edge of the oil tank to restrict personnel and tools from crossing the boundary to contact the high-voltage bushing and ensure the safety of subsequent oil leakage handling operations.

[0082] In one feasible implementation, after oil is injected into the oil tank, the transformer is run for a first period of time, during which patrols and inspections are strengthened. Every second period of time, the transformer's operating status is checked according to the patrol and inspection requirements. During the shift, attention is paid to whether there are any light gas alarm messages in the electrical monitoring background. When any abnormal situation occurs, it is reported in a timely manner and technical personnel are notified to go to the site for judgment and handling.

[0083] In this technical solution, the transformer is run for a period of time to allow air bubbles to accumulate, rise, and be discharged through a gas relay, thus removing residual gas and preventing oil flow disturbances from triggering false trips due to heavy gas. Regular checks of oil level, oil color, leak points, and the condition of the breather silicone sealant are conducted to detect problems such as seal damage and insufficient breather oil seals as early as possible, preventing gas-side leakage from causing insulation deterioration due to moisture, and monitoring the effectiveness of the seal after oil leakage treatment. A light gas alarm indicates minor faults such as inter-turn short circuits. Real-time monitoring combined with manual inspection allows for gas sampling and analysis before the fault escalates, capturing internal fault signs and preventing development into heavy gas trips or insulation breakdown, ensuring the safety of transformer operation. In case of anomalies, technical personnel intervene on-site, forming a closed loop of "monitoring-early warning-intervention" to control risks at the nascent stage. Through time buffering and high-frequency monitoring, gas release, seal verification, and latent fault screening are completed simultaneously during the resting period, ensuring the safety of subsequent heavy gas protection measures.

[0084] Specifically, the first duration is 72 hours, and the second duration is 4 hours.

[0085] In one feasible implementation, after the first operating time is completed, the maintenance and inspection work area will process a second type of work ticket, a high-altitude operation ticket, and a safety briefing sheet. After the equipment room, operation, inspection, and maintenance personnel jointly confirm that the gas relay is free of oil bubbles and the heavy gas protection interlocking pressure plate is not activated, the operation personnel will apply to restore the heavy gas protection interlocking pressure plate to work.

[0086] This technical solution ensures that maintenance operations still meet safety standards after the settling period by issuing work permits, high-altitude operation permits, and safety briefing sheets twice, thus avoiding the risks of falls from heights and electric shocks. It also clarifies risk control measures for oil pressure changes and residual gas during the recovery phase, achieving a closed-loop responsibility system. Multiple parties jointly confirm that the gas relay oil flow is free of air bubbles, verifying that air bubbles have been completely expelled during the settling period after oil injection, and that residual gas has been thoroughly eliminated, preventing residual gas from causing false alarms for heavy gas or frequent alarms for light gas. Checking that the heavy gas protection tripping plate does not activate indicates that no internal faults or oil flow disturbances occurred during the settling period, improving the reliability of protection function recovery. Through a progressive process of reconfirming permits, verifying gas status, testing protection circuits, and binding responsibilities among multiple parties, fault screening, operational compliance, and system reliability verification are completed simultaneously before restoring heavy gas protection. This ensures that the transformer's main protection function can be restored in a timely manner, avoiding the risk of false trips due to incomplete venting, hidden circuit defects, or human error, and guaranteeing the safety and reliability of the transformer operation after oil leakage treatment.

[0087] Furthermore, when air bubbles are present, the venting time should be extended or the sealing should be rechecked. The gas protection interlocking circuit should be tested to ensure that there is no abnormal potential difference and no contact adhesion, so as to ensure that the secondary circuit insulation is intact and to prevent the transformer from being accidentally tripped due to circuit defects after the protection is put into operation. This will ensure that the heavy gas protection interlocking circuit does not trip falsely after the protection is put into operation.

[0088] As shown in Figure 2, according to the second aspect of this application, a sealing and fastening structure for transformer oil leakage is proposed, which is applied to the online treatment method for transformer oil leakage as described in any of the above technical solutions. The sealing and fastening structure includes: a fixing bolt 11, a rubber ring 12, and a nut 13; the fixing bolt 11 passes through the flange 15 and the flange face plate 14 in sequence; the rubber ring 12 is fitted on the outside of the fixing bolt 11, and the rubber ring 12 is in contact with the side of the flange face plate 14 away from the flange 15; the nut 13 is fitted on the fixing bolt 11, and the nut 13 is threadedly connected to the fixing bolt 11, and the nut 13 presses and fixes the rubber ring 12 to the side of the flange face plate 14 away from the flange 15.

[0089] The transformer oil leakage sealing and fastening structure provided in this application embodiment uses a flange 15 and a flange cover plate 14, which are secured by multiple sets of fixing bolts 11 and nuts 13. Rubber rings 12 are added to the fixing bolts 11 of the flange cover plate 14 to replace the original spring sheets and steel gaskets. The rubber rings 12 are then pressed together by the nuts 13 and the flange cover plate 14 to seal the flange cover plate 14 from the outside, thus preventing leakage of insulating oil at the fixing bolts 11. Without disassembling the fixing bolts 11, the transformer can be maintained online without shutting down the generator set, avoiding a sudden increase in power load when the generator is restored. This reduces the maximum demand, ensures the continuity of equipment operation and the stability of power supply, avoids new load spikes, and prevents production interruptions caused by shutdowns, increasing economic benefits. Simultaneously, when dealing with transformer oil leakage online, the generator set can continue generating electricity while the gas is consumed, avoiding the release of gas generated during transformer power outages, reducing resource waste and environmental pollution.

[0090] The transformer oil leakage sealing and fastening structure provided in this application embodiment includes the online treatment method for transformer oil leakage as described in any of the above technical solutions. Therefore, the transformer oil leakage sealing and fastening structure has all the beneficial effects of the online treatment method for transformer oil leakage as described in the above technical solutions, and will not be elaborated here.

[0091] It will be readily understood by those skilled in the art that the above embodiments can be freely combined and superimposed without conflict.

[0092] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A method for online treatment of transformer oil leakage, characterized in that, The online treatment method for transformer oil leakage includes: Fill the oil tank with oil until the oil level in the oil tank is not lower than the first oil level; Release the gas relay until oil flows from the gas relay without any air bubbles, then stop releasing the gas. Rubber rings are installed sequentially on the outside of the fixing bolts of the flange cover plate of the secondary lead of the A-phase current transformer on the high-voltage side of the transformer to seal the outside of the flange cover plate. The method of sequentially installing rubber rings on the outside of the fixing bolts of the flange cover plate of the secondary lead of the A-phase current transformer on the high-voltage side of the transformer to seal the outside of the flange cover plate includes the following steps: Remove the nuts, spring plates, and steel washers from the fixing bolts; A rubber ring is fitted onto the fixing bolt; The nut is then installed back onto the fixing bolt, and the nut and the flange cover plate are used to press the rubber ring together, causing the rubber ring to deform. Repeat the above steps until rubber rings are installed on all of the fixing bolts; The process of injecting oil into the oil tank until the oil level in the oil tank is not lower than the first oil level includes the following steps: Remove the screws inside the vent hole of the oil tank and loosen the main oil tank breather; Inspect the oil filter and install the oil filling pipe on the oil tank; Open the valve on the refueling pipe and inject oil into the oil tank from below through the refueling pipe; When filling with oil, pay attention to the venting situation of the vent hole; Stop adding oil when the oil level gauge shows the first oil level. Close the valve on the refueling hose and remove the refueling hose from the fuel tank; Reinstall the screws of the vent hole and tighten the main oil tank breather.

2. The online treatment method for transformer oil leakage according to claim 1, characterized in that, The first oil level is the seventh cell of the oil level gauge.

3. The online treatment method for transformer oil leakage according to claim 1, characterized in that, The rubber ring is a flat nitrile rubber ring; The inner diameter of the rubber ring is equal to the diameter of the fixing bolt, the outer diameter of the rubber ring is 1.5 to 2 times the diameter of the fixing bolt, and the thickness of the rubber ring is 0.15 to 0.25 times the diameter of the fixing bolt.

4. The online treatment method for transformer oil leakage according to claim 1, characterized in that, The oil leak repair work is carried out on a temporary maintenance platform, which is set up close to the oil tank. The temporary maintenance platform is bounded by the edge of the oil tank, and during the operation, the workers and tools must not cross the boundary.

5. The online treatment method for transformer oil leakage according to claim 4, characterized in that, Before injecting oil into the oil tank until the oil level in the oil tank is not lower than the first oil level, the following steps are also included: Processing electrical maintenance work permits (Type II), work at height permits, and safety briefing sheets; The equipment room, operation, inspection, and maintenance teams jointly confirmed the removal of the heavy gas protection interlock pressure plate. A safety inspection was conducted on the temporary maintenance platform to confirm that it met the operational requirements.

6. The online treatment method for transformer oil leakage according to claim 5, characterized in that, After filling the oil tank with oil, run the transformer for the first period of time, during which time the inspection is strengthened. Every second period of time, check the transformer's operating status according to the inspection requirements. During the shift, pay attention to whether there are any light gas alarm messages in the electrical monitoring background. If any abnormal situation occurs, report it in time and notify the technical personnel to go to the site for judgment and handling.

7. The online treatment method for transformer oil leakage according to claim 6, characterized in that, After the first operating time is completed, the maintenance and inspection work area will process the second type of work ticket, high-altitude operation ticket, and safety briefing form again. After the equipment room, operation, inspection, and maintenance personnel jointly confirm that the gas relay has no air bubbles in the oil flow and the heavy gas protection interlock pressure plate has no action, the operation personnel will apply to restore the heavy gas protection interlock pressure plate to work.

8. A sealing and fastening structure for transformer oil leakage, characterized in that, The sealing and fastening structure, applied to the online treatment method for transformer oil leakage as described in any one of claims 1 to 7, includes: A fixing bolt, which passes sequentially through the flange and the flange faceplate; A rubber ring is fitted onto the outside of the fixing bolt, and the rubber ring is in contact with the side of the flange cover plate opposite to the flange. A nut is fitted onto the fixing bolt and is threadedly connected to the fixing bolt. The nut presses and fixes the rubber ring to the side of the flange cover plate away from the flange.

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