CN-121976857-A - Method for plugging hydrogen leakage of generator end cover under pressure

Abstract

The invention provides a method for leaking hydrogen with pressure and plugging a generator end cover, which comprises the following steps of cleaning the outer edge of a joint surface of a hydrogen-cooled generator and the end cover, polishing and finishing to find each hydrogen leakage point of the outer edge of the joint surface, pasting a sealing surface material at the hydrogen leakage point for plugging, then carrying out leak detection along the outer edge of the joint surface, when the leak detection finds out the hydrogen leakage, adding an inflating valve at the hydrogen leakage point still leaking the hydrogen, pushing the inflating valve to continuously discharge the hydrogen and release the pressure, and simultaneously plugging the periphery of the inflating valve to eliminate the hydrogen leakage point, and installing an inflating valve cap to end the leak detection. By adopting the invention, the pressurized plugging of the generator set of the hydrogen-cooled generator of the power generation enterprise is realized, the sealing surface material is firstly adhered, then the inflating valve is additionally arranged and the plugging is carried out, the use of tools such as a special wrench, a large hammer and the like for fastening bolts is not needed, the safety risk in the operation process is low, the workload is less, and the cost of manpower and material resources is saved.

Inventors

• Nian Hongchang
• LIU YANHUI

Assignees

• 华润电力(宁武)有限公司

Dates

Publication Date

20260505

Application Date

20251218

Claims (10)

1. 1. A method for plugging a generator end cover by hydrogen leakage under pressure is characterized by comprising the following steps: 1. Cleaning the outer edge of the joint surface of the hydrogen-cooled generator (1) and the end cover (3), polishing and finishing, and finding out each hydrogen leakage point of the outer edge of the joint surface; 2. sticking a sealing surface material at the hydrogen leakage point for leakage stoppage, and then carrying out leakage stoppage along the outer edge of the joint surface; 3. When leakage is detected, the inflating valve is additionally arranged at the hydrogen leakage point where hydrogen still leaks, the inflating valve is jacked up to continuously discharge hydrogen and release pressure, meanwhile, the periphery of the inflating valve is blocked, so that the hydrogen leakage point is eliminated, the inflating valve cap is arranged, and the blocking is finished.
2. 2. The method for plugging the generator end cover with hydrogen leakage under pressure according to claim 1, wherein in the first step, the outer edge of the joint surface of the hydrogen-cooled generator (1) and the end cover (3) is cleaned and polished, and specifically comprises the steps of cleaning greasy dirt, paint skin and accumulated dust of the end cover (3), polishing sharp corner burrs on the outer edge of the joint surface of the end cover (3) by using a file, and then scrubbing after polishing and polishing by using sand paper.
3. 3. The method for plugging the generator end cover with hydrogen leakage under pressure according to claim 2, wherein the method is characterized by comprising the steps of polishing and cleaning by using sand paper, specifically comprising the steps of polishing and cleaning rust by using No. 0 sand paper, polishing by using 800-mesh sand paper for the second time, further polishing and cleaning by using 1800-mesh metallographic sand paper, and finally repeatedly cleaning by using white cloth dipped with alcohol.
4. 4. The method for plugging the generator end cover with hydrogen leakage under pressure according to claim 1, wherein in the second step, a sealing surface material is stuck at the hydrogen leakage point for plugging, and specifically comprises the steps of coating the strong glue at the hydrogen leakage point at the outer edge of the bonding surface, folding the sealing surface material into an included angle matched with the outer edge of the bonding surface, sticking the sealing surface material at the hydrogen leakage point, and compacting until the strong glue is solidified.
5. 5. The method of claim 4 wherein the sealing surface material is 50um stainless steel.
6. 6. The method for plugging the generator end cover hydrogen leakage under pressure according to claim 1, wherein the third step specifically comprises the steps of adding a valve at a hydrogen leakage point still leaking hydrogen, fixedly connecting the periphery of a base of the valve with the outer edge of a joint surface by using plugging glue, then pushing the valve to continuously discharge hydrogen and release pressure, continuously laying the plugging glue at the periphery of the valve to eliminate the hydrogen leakage point, installing a valve cap, and ending the plugging.
7. 7. The method for plugging hydrogen leakage with pressure on the generator end cover according to claim 6, wherein the step of continuously laying plugging glue on the periphery of the valve is characterized by comprising the steps of continuously laying the plugging glue on the outer edge surface of a joint surface in the range of at least 3cm on both sides of the valve, and continuously applying pressure to the place where the plugging glue is laid for a preset time to solidify the glue.
8. 8. The method for plugging a generator end cover with hydrogen leakage under pressure according to claim 7, wherein the method is characterized in that the pressure is continuously applied to the position where the plugging glue is applied for a preset time, after the glue is solidified, the method further comprises the steps of detecting the condition of hydrogen leakage, such as eliminating the hydrogen leakage point, installing a valve cap, stopping the glue spraying, after keeping for 10 minutes, detecting the condition of hydrogen leakage again, such as eliminating the hydrogen leakage point, stopping the leakage, and repeating the step three at the position where the hydrogen leakage point is transferred, such as detecting the transition of the hydrogen leakage point.
9. 9. The method for plugging the generator end cover with hydrogen leakage under pressure according to any one of claims 1 to 8 is characterized by further comprising the following steps of carrying out leak detection on a bolt part of the end cover (3), if no hydrogen leakage exists, stopping the leak, if the hydrogen leakage exists, carrying out integral paint removal treatment on the bolt where the hydrogen leakage exists, cleaning, polishing and finishing, uniformly arranging at least three inflating valves around the axis of the bolt, fixedly connecting the periphery of the base of the inflating valve with the root of the bolt head by using plugging glue, then jacking the inflating valve, continuously discharging the hydrogen for pressure relief, coating the bolt by using the plugging glue until the hydrogen leakage does not exist at the detected bolt part, installing an inflating valve cap, detecting the hydrogen leakage concentration of the inflating valve again, and stopping the leak stopping after the hydrogen leakage is not obvious.
10. 10. The method for plugging the hydrogen leakage of the generator end cover with pressure according to claim 9, wherein the method further comprises the step of carrying out leakage detection on the outer edge of the joint surface of the hydrogen-cooled generator (1) and the end cover (3) and bolts after twenty-four hours, and confirming no leakage point.

Description

Method for plugging hydrogen leakage of generator end cover under pressure Technical Field The invention relates to the technical field of hydrogen cooling generator end covers, in particular to a method for plugging a generator end cover by hydrogen leakage under pressure. Background In power generation enterprises, the hydrogen leakage of the hydrogen-cooled generator directly affects the safe operation of the unit, and is one of the main technical indexes of the operation of the turbo generator unit. The hydrogen leakage point is required to be checked for controlling the hydrogen leakage, and a method is adopted in time to perform the leakage blocking. The joint surface of the end part of the generator and the end cover and the bolt of the end cover are common hydrogen leakage points, and two common plugging methods are adopted. Firstly, the bolts are fastened and the sealant is smeared to quickly leak stoppage. The mode is mainly used for the conditions that bolts are loosened and bolt gaskets are not deformed, but the difficulty in grasping the strength during bolt fastening is high due to the pressure treatment, and the hydrogen leakage amount is possibly increased. And secondly, when the generator is stopped, checking and plugging comprehensively, polishing and cleaning the joint surface of the end cover, replacing the rubber sealing gasket of the end cover and uniformly fastening the bolts. The method is effective in treatment, but needs to be carried out after hydrogen replacement in a machine set shutdown state, has large workload, and is difficult to meet the requirements of safe and stable operation of the generator when an emergency occurs. Disclosure of Invention In order to solve at least one of the technical problems, the invention provides a method for plugging the generator end cover by hydrogen leakage under pressure. The technical scheme for solving the technical problems is as follows: the invention provides a method for plugging a generator end cover with hydrogen under pressure, which comprises the following steps: 1. Cleaning the outer edge of the joint surface of the hydrogen-cooled generator and the end cover, polishing and finishing, and finding out each hydrogen leakage point of the outer edge of the joint surface; 2. sticking a sealing surface material at the hydrogen leakage point for leakage stoppage, and then carrying out leakage stoppage along the outer edge of the joint surface; 3. When leakage is detected, the inflating valve is additionally arranged at the hydrogen leakage point where hydrogen still leaks, the inflating valve is jacked up to continuously discharge hydrogen and release pressure, meanwhile, the periphery of the inflating valve is blocked, so that the hydrogen leakage point is eliminated, the inflating valve cap is arranged, and the blocking is finished. The beneficial effects of the invention are as follows: The invention realizes the pressurized plugging during the unit operation of the hydrogen-cooled generator of the power generation enterprise, and the sealing surface material is firstly adhered, then the valve is additionally arranged and the sealing is carried out, so that tools such as a special wrench, a large hammer and the like are not required to be used for fastening bolts, the safety risk in the operation process is low, the workload is also less, the cost of manpower and material resources is saved, and meanwhile, the valve is additionally arranged to carry out hydrogen discharging and pressure relief, the influence of the invasion of hydrogen leakage on the sealing performance when the sealing material is not solidified is avoided, and the hydrogen plugging effect is good. On the basis of the technical scheme, the invention can be improved as follows. In the first step, the outer edge of the joint surface of the hydrogen-cooled generator and the end cover is cleaned and polished, and the method specifically comprises the steps of cleaning greasy dirt, paint skin and deposited dust of the end cover, polishing sharp corner burrs on the outer edge of the joint surface of the end cover by using a file, and then polishing and polishing by using sand paper and then scrubbing. The cleaning is convenient to ensure, the subsequent sealing surface material and the plugging adhesive are tightly attached to the outer edge surface of the joint surface, and the subsequent plugging is smooth. Further, the abrasive paper is used for polishing and cleaning, and the method specifically comprises the steps of polishing and cleaning rust by using No. 0 abrasive paper, polishing by using 800-mesh abrasive paper for the second time, further polishing and cleaning by using 1800-mesh metallographic abrasive paper, and finally repeatedly cleaning by using white cloth dipped with alcohol. Through changing the abrasive paper that roughness is less in proper order, the polishing efficiency is high, has improved the finish of faying face outer fringe surface after polis