An on-line nitrogen filling maintenance method for the stator winding of a large generator

Abstract

The present invention discloses an on-line nitrogen filling maintenance method for the stator winding of a large generator, which includes using a replacement technique to drain the hydrogen in the generator; using a purging and drying device to remove the water stored in the water circuit of the stator winding of the generator; and, connecting the pipeline between the water circuit of the stator winding of the generator and the nitrogen generator and filling nitrogen into the water circuit of the stator winding of the generator through the nitrogen generator. The present invention utilizes the nitrogen generator of the existing boiler nitrogen filling maintenance system, and the nitrogen required for maintenance is led from the nitrogen mother pipe at the outlet of the nitrogen generator and directly led to the water circuit system of the stator winding of the generator through a pipeline. The nitrogen pipeline maintains a pressure of 0.1 MPA for a long time, and it will not cause humid air to enter the water circuit system of the stator winding of the generator, thereby ensuring the nitrogen filling maintenance effect of the stator winding of the generator; it is not necessary to disassemble some pipelines and connecting doors of the water circuit system of the stator winding of the generator, and the process flow is simple and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of electron nitrogen filling maintenance, in particular to an on-line nitrogen filling maintenance method for the stator winding of a large generator. Background Art

[0002] When a large generator is out of service for a long time, the water stored in the waterway of the stator winding should be drained, and the residual water in the waterway of the stator winding should be dried with dry compressed air. Finally, nitrogen gas at 0.1 MPA should be filled into the waterway of the stator winding to prevent the waterway of the stator winding from being blocked due to the oxidation of the inner wall of the hollow copper wire of the generator stator winding, thereby causing a major accident of damage to the generator stator winding during operation. Summary of the Invention

[0003] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title. However, such simplifications or omissions shall not be used to limit the scope of the present invention.

[0004] In view of the problems existing in the prior art, the present invention is proposed.

[0005] Therefore, the technical problem to be solved by the present invention is that the waterway systems of most generator stator windings are complex and cannot be completely sealed, resulting in nitrogen leakage; it is necessary to regularly open the flange to supplement nitrogen, which will cause humid air to enter the waterway system of the generator stator winding, greatly reducing the effect of nitrogen filling maintenance for the generator stator winding, and the process flow is complex.

[0006] To solve the above technical problems, the present invention provides the following technical solution: an on-line nitrogen filling maintenance method for the stator winding of a large generator, which includes using a displacement technique to drain the hydrogen in the generator;

[0007] using a purging and drying device to dry the water stored in the waterway of the generator stator winding; and,

[0008] Connect the pipeline between the waterway of the generator stator winding and the nitrogen generator and fill nitrogen into the waterway of the generator stator winding through the nitrogen generator; a nitrogen production pipeline and a nitrogen inlet pipeline are laid between the waterway of the generator stator winding and the nitrogen generator. The inside of the nitrogen production pipeline is provided with a movable conduction door, and the conduction door is a sector plate structure surrounded by multiple circles; the inner wall of the nitrogen production pipeline is provided with a second ring plate, and the second ring plate is rotatably connected to the inner wall of the nitrogen production pipeline. A second ring pipe protrudes towards the nitrogen inlet pipeline on the second ring plate; a third ring plate is vertically arranged on the inner wall of the second ring pipe, and an annular airbag is fixedly connected to the third ring plate. The other end of the annular airbag is fixedly connected to a fourth ring plate, the outer wall of the fourth ring plate fits and fixes the inner wall of the fixed ring block, and a connecting block protrudes on the fourth ring plate and is slidably connected by being embedded in a chute.

[0009] As a preferred embodiment of the on-line nitrogen charging maintenance method for the stator winding of the large generator described in the present invention, wherein: the replacement technology includes: connecting a conduit to the carbon dioxide pipeline at the hydrogen panel, introducing carbon dioxide to discharge the hydrogen in the generator casing, and then introducing compressed air to discharge the carbon dioxide in the generator casing.

[0010] As a preferred embodiment of the on-line nitrogen charging maintenance method for the stator winding of the large generator described in the present invention, wherein: during the process of discharging hydrogen with carbon dioxide, maintain the gauge pressure inside the carbon dioxide pipe at 0.6 - 0.8 MPA, and measure the carbon dioxide purity when the system reaches the steady-state operation condition; during the process of discharging carbon dioxide with compressed air, measure the humidity of the compressed air when the system reaches the preset carbon dioxide concentration threshold.

[0011] As a preferred embodiment of the on-line nitrogen charging maintenance method for the stator winding of the large generator described in the present invention, wherein: the drying device is respectively connected to the inlet and outlet flanges of the generator stator water system, and uses the positive and reverse purging method with compressed air to blow the water into the drying device.

[0012] As a preferred embodiment of the on-line nitrogen charging maintenance method for the stator winding of the large generator described in the present invention, wherein: during positive purging, the compressed air enters from the inlet of the generator stator water system through the drying device and returns to the drying device from the outlet of the generator stator water system; during reverse purging, the compressed air enters from the outlet of the generator stator water system through the drying device and returns to the drying device from the inlet of the generator stator water system.

[0013] As a preferred embodiment of the on-line nitrogen charging maintenance method for the stator winding of the large generator described in the present invention, wherein: the nitrogen production pipeline is connected to the water circuit of the generator stator winding, the nitrogen inlet pipeline is connected to the nitrogen generator, and the nitrogen production pipeline and the nitrogen inlet pipeline are connected in a sliding and movable manner.

[0014] As a preferred embodiment of the on-line nitrogen charging maintenance method for the stator winding of the large generator described in the present invention, wherein: a pressure boosting valve is provided on the nitrogen inlet pipeline, a pressure reducing valve is provided on the nitrogen production pipeline, and the pressure reducing valve controls the pressure of nitrogen in the nitrogen production pipeline not exceeding 0.1 MPA.

[0015] As a preferred embodiment of the on-line nitrogen charging maintenance method for the stator winding of the large generator described in the present invention, wherein: a fixed ring block slidably connected to the nitrogen inlet pipeline is sleeved on the outer wall of the nitrogen inlet pipeline, a first ring plate is provided on the inner wall of one end of the nitrogen inlet pipeline, a first ring pipe protruding towards the nitrogen production pipeline is provided on the first ring plate, the first ring pipe extends into the nitrogen production pipeline and is connected in cooperation with a conduction door, the fixed ring block is of a circular ring structure and is coaxially arranged with the nitrogen inlet pipeline, and a plurality of chutes are provided on the inner circumference of the inner wall of the fixed ring block, and a plurality of sliders protruding from the outer wall of the nitrogen inlet pipeline are embedded in the chutes and are slidably connected.

[0016] As a preferred embodiment of the on-line nitrogen filling maintenance method for the stator winding of large generators described in the present invention, the following is provided: The second annular pipe is rotatably connected to the second annular plate, and the second annular pipe corresponds to the fixed annular block.

[0017] Advantages of the present invention: The present invention utilizes the nitrogen generator of the existing boiler nitrogen filling maintenance system. The nitrogen required for maintenance is led from the nitrogen mother pipe at the outlet of the nitrogen generator and directly led to the water circuit system of the generator stator winding through a pipeline. The nitrogen pipeline maintains a pressure of 0.1 MPA for a long time, and it will not cause humid air to enter the water circuit system of the generator stator winding, thus ensuring the nitrogen filling maintenance effect of the generator stator winding; there is no need to disassemble some pipelines and conduction doors of the water circuit system of the generator stator winding, and the process flow is simple and reliable. Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts. Among them:

[0019] Figure 1 It is a flowchart of the nitrogen filling maintenance method in the first embodiment.

[0020] Figure 2 It is a block diagram of the pipeline connection of the nitrogen generator in the first embodiment.

[0021] Figure 3 It is a sectional view of the nitrogen production pipeline in the second embodiment.

[0022] Figure 4 For the second embodiment Figure 3 front view.

[0023] Figure 5 For the second embodiment Figure 3 rear view.

[0024] Figure 6 It is an explosion structure diagram of the nitrogen production pipeline and the nitrogen inlet pipeline in the third embodiment.

[0025] Figure 7 It is a clamping structure diagram of the small ball in the third embodiment. Detailed Embodiments

[0026] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following will make a detailed description of the specific embodiments of the present invention in conjunction with the drawings in the specification.

[0027] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention may be implemented in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the essence of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0028] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or selectively exclusive embodiments from other embodiments.

[0029] Embodiment 1

[0030] Refer to Figure 1 、 2 , which is the first embodiment of the present invention. This embodiment provides an on-line nitrogen filling maintenance method for the stator winding of a large generator, including the following steps:

[0031] S1. Use the replacement technology to drain the hydrogen in the generator. The replacement method is "hydrogen - carbon dioxide - air replacement". Hydrogen is a highly flammable gas, colorless, transparent, odorless, and insoluble in water. The purpose of draining the hydrogen is to avoid the dangerous hydrogen explosion caused by the mixing of hydrogen and oxygen.

[0032] Furthermore, in the stator water system of the generator, connect the conduit at the hydrogen disk to the carbon dioxide pipeline, and use carbon dioxide gas to discharge the hydrogen in the machine shell. Pay attention to the dead corners. The internal gauge pressure of the carbon dioxide pipeline during replacement is 0.6 - 0.8 MPA. When the system reaches the steady-state operation condition, measure the carbon dioxide purity.

[0033] Then connect the air compressor and introduce compressed air to discharge the carbon dioxide in the generator housing so that only air remains in the generator housing. Using this method, the hydrogen can be safely and completely discharged.

[0034] S2. Use a purging and drying device to dry the water stored in the stator winding waterway of the generator. The purging method uses positive and reverse purging, which has a better effect. Specifically, the drying device is respectively connected to the inlet and outlet flanges of the stator water system of the generator, and the positive and reverse purging method with compressed air is used to blow the water into the drying device.

[0035] During positive purging, the compressed air enters from the inlet of the stator water system of the generator through the drying device and returns to the drying device from the outlet of the stator water system of the generator; during reverse purging, the compressed air enters from the outlet of the stator water system of the generator through the drying device and returns to the inlet of the stator water system of the generator.

[0036] Furthermore, the specific operation steps are as follows:

[0037] Step 2.1: Press the stop button of the generator stator water pump to stop the operation of the generator stator water pump, and check that the conduction doors on both sides of the gas trap are closed.

[0038] Step 2.2: Remove a section of each of the inlet and outlet pipes of the generator stator water, check that the connection between the purging and drying device and the flanges of the stator water inlet and outlet is intact, and the connection between the drying device and the compressed air pipeline is intact. After measuring that the quality of the compressed air is qualified, start the purging and drying work.

[0039] Step 2.3: Purge back and forth with compressed air to blow the water into the drying device.

[0040] Step 2.4: Manually open the conduction door of the sampling circuit irregularly for ventilation and purging. The sampling circuit is an existing device in the generator stator water system, which is used to collect the conduction pressure during purging, and then the conduction door can be adjusted in real time to control the increase or decrease of the purging pressure.

[0041] Step 2.5: Restore the removed pipes and systems, and pay attention that no sundries enter the stator water system during the restoration process.

[0042] S3. Connect the pipe between the generator stator winding waterway and the nitrogen generator, and fill nitrogen into the generator stator winding waterway through the nitrogen generator. A nitrogen production pipe 100 and a nitrogen inlet pipe 200 are laid between the generator stator winding waterway and the nitrogen generator. The nitrogen production pipe 100 is connected to the generator stator winding waterway, the nitrogen inlet pipe 200 is connected to the nitrogen generator, and the nitrogen production pipe 100 and the nitrogen inlet pipe 200 are connected in a sliding and movable manner.

[0043] Furthermore, a pressure regulating valve C is provided on the nitrogen inlet pipe 200, and a pressure reducing valve D is provided on the nitrogen production pipe 100. The pressure reducing valve D controls the pressure of nitrogen in the nitrogen production pipe 100 not to exceed 0.1 MPA.

[0044] Example 2

[0045] Refer to Figures 3 - 5 , which is the second embodiment of the present invention. Based on the previous embodiment, the connection between the nitrogen production pipe 100 and the nitrogen inlet pipe 200 is sealed, and a conduction door 101 that can control the on-off is provided inside the nitrogen production pipe 100.

[0046] The nitrogen production pipe 100 is connected to the generator stator winding waterway, and the nitrogen inlet pipe 200 is connected to the nitrogen generator; an active conduction door 101 is provided inside the nitrogen production pipe 100. The conduction door 101 is of a fan-shaped structure and is provided with a plurality of circles arranged around it. The conduction door 101 can be opened by the limiting structure as it moves along the groove when rotating the end of the nitrogen production pipe 100, so as to connect the nitrogen production pipe 100 and the nitrogen inlet pipe 200.

[0047] Further, both the nitrogen inlet pipe 200 and the nitrogen generation pipe 100 are of circular pipe structures. The size of the nitrogen generation pipe 100 is larger than that of the nitrogen inlet pipe 200. One end of the nitrogen inlet pipe 200 extends into the nitrogen generation pipe 100 for connection. A fixed ring block 201 that is slidably connected to the nitrogen inlet pipe 200 is sleeved on the outer wall of the nitrogen inlet pipe 200. The fixed ring block 201 is of a circular ring tubular structure. A first ring plate 202 is provided on the inner wall of one end of the nitrogen inlet pipe 200. A first ring pipe 203 that protrudes towards the nitrogen generation pipe 100 is provided on the first ring plate 202. The first ring pipe 203 extends into the nitrogen generation pipe 100 and is connected to the conduction door 101 in a cooperative manner. Here, the cooperation means that the nitrogen inlet pipe 200 rotates to drive the conduction door 101 structure to open. The fixed ring block 201 is of a circular ring structure and is coaxially arranged with the nitrogen inlet pipe 200. Multiple sliding grooves 201a are provided on the circumference of the inner wall of the fixed ring block 201 towards the nitrogen generation pipe 100. The sliding grooves 201a are of a long strip structure and are arranged along the length direction of the fixed ring block 201. Specifically, the inner wall diameter of one end of the fixed ring block 201 is smaller than that of the other end. Therefore, one end of the fixed ring block 201 is closely attached to the outer wall of the nitrogen inlet pipe 200, and the other end is spaced from the outer wall of the nitrogen inlet pipe 200 by a certain distance. Multiple slider A are protrudingly provided on the outer wall of one end of the nitrogen inlet pipe 200. The slider A is embedded in the sliding groove 201a for sliding connection.

[0048] Further, a second ring plate 102 is provided on the inner wall of the nitrogen generation pipe 100. The second ring plate 102 is rotatably connected to the inner wall of the nitrogen generation pipe 100. A second ring pipe 102a that protrudes towards the nitrogen inlet pipe 200 is provided on the second ring plate 102. The second ring pipe 102a is rotatably connected to the second ring plate 102 and is fixedly connected to the inner wall of the nitrogen generation pipe 100 through a connecting rod. The second ring pipe 102a corresponds to the fixed ring block 201 and is separated by a certain distance. The fixed ring block 201 is fixed on the outer wall of the nitrogen inlet pipe 200 and is axially slidably connected to the outer wall of the nitrogen inlet pipe 200. The fixed ring block 201 is fixedly connected to the inner wall of the nitrogen generation pipe 100 through a fixing rod. Therefore, the fixed ring block 201 can remain stationary. Usually, the nitrogen generation pipe 100 is fixed, so the second ring pipe 102a is fixed, and the second ring plate 102 can rotate so that the conduction door 101 can be opened under a rotational action.

[0049] Specifically, the nitrogen generation pipe 100 is provided with two chambers, and the two chambers are isolated by the conduction door 101. When the conduction door 101 is opened, the inner chamber of the nitrogen inlet pipe 200 is communicated with the nitrogen generation pipe 100.

[0050] Further, a third ring plate 103 is vertically arranged on the inner wall of the second annular pipe 102a. An annular airbag 103a is fixedly connected to the third ring plate 103, and the other end of the annular airbag 103a is fixedly connected to a fourth ring plate 104. The annular airbag 103a is an elastic soft structure. When the annular airbag 103a is filled with gas, it has a strong elastic effect. The annular airbag 103a connects the third ring plate 103 and a fixed ring block 201 on the nitrogen inlet pipe 200. Since there is a certain distance between the second annular pipe 102a and the fixed ring block 201, when the annular airbag 103a is inflated, it will be extruded from between the second annular pipe 102a and the fixed ring block 201 and abut against the inner wall of the nitrogen production pipe 100. Then, when the annular airbag 103a is filled with gas, it will have an elastic and sealing effect. The outer wall of the fourth ring plate 104 fits against the inner wall of the fixed ring block 201, and a connecting block 104a protrudes from the fourth ring plate 104 and is slidably connected by being embedded in a chute 201a.

[0051] Further, when filling nitrogen, the annular airbag 103a will be extruded. At the same time, the connecting block 104a will move along the chute 201a and provide space for the movement of the slider A. At this time, the nitrogen inlet pipe 200 can move axially. The first annular pipe 203 moves towards the nitrogen production pipe 100 along with the movement and cooperates with the rotation of the conduction door 101. The cooperation structure is as follows: A fifth annular pipe 102c is arranged on the second ring plate 102 along the direction of the second annular pipe 102a. The fifth annular pipe 102c is fixedly connected to the second ring plate 102 and the fifth annular pipe 102c is located inside the second annular pipe 102a. The fifth annular pipe 102c is coaxially located inside the second annular pipe 102a and the first annular pipe 203 is in a spiral fit with the fifth annular pipe 102c. When the nitrogen inlet pipe 200 moves axially, the outer wall of the fifth annular pipe 102c is in a spiral connection with the inner wall of the second annular pipe 102a. When the second annular pipe 102a moves linearly, under the spiral fit, the fifth annular pipe 102c drives the second ring plate 102 to rotate and simultaneously opens the conduction door 101.

[0052] At the same time, after the fifth annular pipe 102c is inserted into the second annular pipe 102a, the outside of the fifth annular pipe 102c (i.e., the space where the annular airbag 103a is located) is in a sealed state, maintaining a certain pressure on the annular airbag 103a.

[0053] Embodiment 3

[0054] Refer to Figure 6 、 7 This is the third embodiment of the present invention. Based on the previous embodiment, the conduction door 101 adopts a rotary structure for opening and closing, specifically as follows:

[0055] The inner wall of the nitrogen production pipeline 100 is further provided with a valve fixing plate 105. The valve fixing plate 105 is of an annular structure, and the conduction door 101 is located between the valve fixing plate 105 and the second ring plate 102; the conduction door 101 is of a sector plate structure surrounded by multiple circles. Multiple conduction doors 101 enclose a circle, and it can expand or contract outward when rotating to form an open and closed state; on the second ring plate 102 between the second ring pipe 102a and the nitrogen production pipeline 100, multiple inclined through grooves 102b are circumferentially arranged. One side of the conduction door 101 is movably connected by inserting a round shaft rod 101a into the through groove 102b. Multiple vertical grooves 105a are circumferentially arranged on the valve fixing plate 105. On the other side of the conduction door 101 relative to the round shaft rod 101a, a sliding shaft 101b is provided, and the sliding shaft 101b is inserted into the vertical groove 105a for movable connection.

[0056] When the second ring plate 102 is driven to rotate, due to the inclined arrangement of the through groove 102b, the distances of its two ends relative to the center are inconsistent, and with the vertical direction limit of the vertical groove 105a, the conduction door 101 can only expand or contract. Therefore, when the round shaft rod 101a of the conduction door 101 moves to the farther end of the through groove 102b, the conduction door 101 is opened.

[0057] Furthermore, a guiding spiral groove 102c-1 is provided on the inner wall of the fifth ring pipe 102c. A clamping block 203a is provided on the outer wall of the first ring pipe 203. The clamping block 203a extends into the guiding spiral groove 102c-1 from the end of the guiding spiral groove 102c-1 and cooperates with the guiding spiral groove 102c-1. Here, the cooperation means that when the second ring pipe 102a is moved to the port of the fifth ring pipe 102c, the clamping block 203a extends into the guiding spiral groove 102c-1 from the end of the guiding spiral groove 102c-1. Due to the axial movement of the second ring pipe 102a, the guiding spiral groove 102c-1 will rotate under the drive of the clamping block 203a to control the opening or closing of the conduction door 101.

[0058] On the outer wall of the first ring pipe 203, through holes 203b are also circumferentially arranged. When filling with nitrogen, nitrogen can enter the space where the annular airbag 103a is located from the through holes 203b; and a circular guide plate 203c is inclinedly arranged on the inner wall of the end of the first ring pipe 203 facing the nitrogen production pipeline 100, which helps the nitrogen to enter and then pass through the through holes 203b along the guide plate 203c.

[0059] After the axial movement of the second ring pipe 102a is cooperated to enter the fifth ring pipe 102c, the nitrogen inlet pipeline 200 is fixed by using a clamping structure to make the connection of the two pipelines stable when filling with nitrogen.

[0060] Specifically, a sealing ring plate 203d is provided on the outer wall of the first annular pipe 203, and an extension plate 203d-1 is vertically provided thereon. The extension plate 203d-1 extends in the direction of the nitrogen production pipeline 100 and is dimensionally matched with the inner wall of the third ring plate 103. The inner wall of the extension plate 203d-1 is dimensionally matched with the outer wall of the fifth annular pipe 102c. The extension plate 203d-1 can pass through between the fifth annular pipe 102c and the third ring plate 103 and closely adhere to the inner wall of the third ring plate 103 and the outer wall of the fifth annular pipe 102c to form a seal.

[0061] Further, elastic members 103b are horizontally penetrated and arranged on the third ring plate 103 and a plurality of them are arranged circumferentially. They are located inside the annular airbag 103a. The center axis of the elastic member 103b penetrates through a round rod 103c. A limiting shell 103c-1 is arranged in the direction of the second ring plate 102 on the round rod 103c. The limiting shell 103c-1 is fixedly connected to the elastic member 103b.

[0062] Further, the bottom of the limiting shell 103c-1 penetrates through a first round hole 103c-2. A small ball 103c-3 is placed inside the limiting shell 103c-1. The bottom of the limiting shell 103c-1 penetrates through the first round hole 103c-2. A second round hole 203d-2 is provided on the outer wall of the extension plate 203d-1. The first round hole 103c-2 corresponds to the second round hole 203d-2 and they have the same size. The small ball 103c-3 is erected in the first round hole 103c-2 and is engaged with the second round hole 203d-2. The cooperation here means that when the extension plate 203d-1 is inserted against the outer wall of the fifth annular pipe 102c, it passes through the bottom of the limiting shell 103c-1 and can lift the small ball 103c-3 at the same time. When the first round hole 103c-2 corresponds to the second round hole 203d-2, a part of the small ball 103c-3 falls from the first round hole 103c-2 into the second round hole 203d-2, so that the extension plate 203d-1 is engaged with the limiting shell 103c-1, thereby fixing the nitrogen inlet pipe 200.

[0063] Further, an L-shaped attracting plate B is connected to the inner wall of the second annular pipe 102a. The end of the attracting plate B faces the end wall of the limiting shell 103c-1 and is attractively engaged with the small ball 103c-3 inside the limiting shell 103c-1. When releasing the fixation of the nitrogen inlet pipe 200, continue to push the nitrogen inlet pipe 200. The extension plate 203d-1 squeezes the elastic member 103b, causing the round rod 103c to be pushed. The limiting shell 103c-1 then touches the end of the L-shaped attracting plate B. The small ball 103c-3 is made of iron and is attracted by the L-shaped attracting plate B, so as to release the engagement fixation between the first round hole 103c-2 and the second round hole 203d-2, and then the nitrogen inlet pipe 200 can be withdrawn.

[0064] Importantly, it should be noted that the construction and arrangement of the present application shown in multiple different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those skilled in the art who refer to this disclosure should easily understand that many modifications are possible without substantially departing from the novel teachings and advantages of the subject matter described in this application (e.g., changes in the dimensions, scales, structures, shapes and proportions of various elements, as well as parameter values (such as temperature, pressure, etc.), installation arrangements, use of materials, colors, orientations, etc.). For example, elements shown as integrally formed may be composed of multiple parts or elements, the positions of the elements may be inverted or otherwise changed, and the nature, number or position of discrete elements may be altered or changed. Accordingly, all such modifications are intended to be included within the scope of the present invention. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "means-plus-function" clauses are intended to cover the structures that perform the recited functions herein, and not only structurally equivalent but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present invention. Therefore, the present invention is not limited to specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0065] In addition, to provide a concise description of the exemplary embodiments, not all features of the actual embodiments may be described (i.e., those features that are not relevant to the currently contemplated best mode of carrying out the present invention or those that are not relevant to the implementation of the present invention).

[0066] It should be understood that in the development of any actual implementation, as in any engineering or design project, numerous specific implementation decisions may be made. Such development efforts may be complex and time-consuming, but for those of ordinary skill in the art who benefit from this disclosure, without excessive experimentation, such development efforts will be routine work in design, manufacturing and production.

[0067] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for online nitrogen filling maintenance of large generator stator windings, characterized by: include, Use displacement technology to exhaust the hydrogen in the generator; Use a purge drying device to dry the water in the generator stator winding water channel; and, Connecting the pipeline between the generator stator winding water channel and the nitrogen generator and filling the generator stator winding water channel with nitrogen through the nitrogen generator; A nitrogen production pipeline (100) and a nitrogen inlet pipeline (200) are laid between the generator stator winding water channel and the nitrogen generator. A movable conduction door (101) is provided inside the nitrogen production pipeline (100). The conduction door (101) is a sector plate structure surrounded by multiple circles. A second ring plate (102) is provided on the inner wall of the nitrogen production pipeline (100). The second ring plate (102) is rotatably connected to the inner wall of the nitrogen production pipeline (100). A second ring plate (102) is protruding toward the nitrogen inlet pipeline (200). A ring tube (102a); a third ring plate (103) is vertically arranged on the inner wall of the second ring tube (102a); an annular airbag (103a) is fixedly connected to the third ring plate (103); the other end of the annular airbag (103a) is fixedly connected to the fourth ring plate (104); the outer wall of the fourth ring plate (104) fits the inner wall of the fixed ring block (201); a connecting block (104a) is protrudingly arranged on the fourth ring plate (104); the connecting block (104a) is embedded in the slide groove (201a) for sliding connection.

2. The method for online nitrogen filling maintenance of large generator stator windings according to claim 1, characterized in that: The replacement techniques include: Connect the conduit to the carbon dioxide pipeline at the hydrogen tray, introduce carbon dioxide to discharge the hydrogen in the generator casing, and then introduce compressed air to discharge the carbon dioxide in the generator casing.

3. The method for online nitrogen filling maintenance of large generator stator windings according to claim 2, characterized in that: During the carbon dioxide hydrogen discharge process, the gauge pressure in the carbon dioxide pipe is maintained at 0.6-0.8MPA. When the system reaches steady-state operating conditions, the carbon dioxide purity is measured. During the compressed air carbon dioxide discharge process, when the system reaches the preset carbon dioxide concentration threshold, the compressed air humidity is measured.

4. The method for online nitrogen filling maintenance of large generator stator windings according to any one of claims 1 to 3, characterized in that: The drying device is connected to the water inlet and outlet flanges of the generator stator water system respectively, and uses compressed air forward and reverse blowing to blow water into the drying device.

5. The method for online nitrogen filling maintenance of large generator stator windings according to claim 4, characterized in that: During the purge, the compressed air enters the generator stator water system from the water inlet through the drying device and returns to the drying device from the water outlet of the generator stator water system; During back-purging, compressed air enters the generator stator water system outlet through the drying device and returns to the drying device from the generator stator water system inlet.

6. The method for online nitrogen filling maintenance of large generator stator windings according to claim 5, characterized in that: The nitrogen production pipeline (100) is connected to the generator stator winding water channel, the nitrogen inlet pipeline (200) is connected to the nitrogen generator, and the nitrogen production pipeline (100) and the nitrogen inlet pipeline (200) are connected in a sliding movable manner.

7. The method for online nitrogen filling maintenance of large generator stator windings according to claim 6, characterized in that: The nitrogen inlet pipeline (200) is provided with a pressurizing valve (C), and the nitrogen production pipeline (100) is provided with a pressure reducing valve (D). The pressure reducing valve (D) controls the pressure of the nitrogen in the nitrogen production pipeline (100) to not exceed 0.1 MPa.

8. The method for online nitrogen filling maintenance of large generator stator windings according to claim 3, characterized in that: The outer wall of the nitrogen inlet pipeline (200) is provided with a fixed ring block (201) that is slidably connected to the nitrogen inlet pipeline (200); a first ring plate (202) is provided on the inner wall of one end of the nitrogen inlet pipeline (200); the first ring plate (202) is provided with a first ring tube (203) protruding toward the nitrogen production pipeline (100); the first ring tube (203) extends into the nitrogen production pipeline (100) and is connected to the conduction gate (101); the fixed ring block (201) is an annular structure and is coaxially arranged with the nitrogen inlet pipeline (200); and a plurality of slide grooves (201a) are provided on the inner wall of the fixed ring block (201); a plurality of sliders (A) are protruding from the outer wall of the nitrogen inlet pipeline (200); and the sliders (A) are embedded in the slide grooves (201a) for slidable connection.

9. The method for online nitrogen filling maintenance of large generator stator windings according to claim 8, characterized in that: The second ring tube (102a) is rotatably connected to the second ring plate (102), and the second ring tube (102a) corresponds to the fixed ring block (201).

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