A steam turbine instrument signal line sealing structure and sealing method thereof

Abstract

The present invention discloses a sealing structure for a steam turbine instrument signal line and a sealing method thereof, which comprises a box wall of a steam turbine and an instrument signal line, wherein the box wall is provided with a signal hole, a signal tube is provided in the signal hole, both ends of the signal tube are fixed to the box wall by nuts, the instrument signal line passes through the signal tube and is led out of the box, a junction box 1 is provided on the inner side of the box wall, the junction box 1 is provided with a side box cover, the bottom end is tilted and provided with an oil drain hole, the instrument signal line passes through the side box cover and the signal tube upwardly and enters the outer junction box 2, and the instrument signal line passes horizontally through the side box cover of the junction box 2 and is connected to an external secondary instrument. After the modification construction, the oil leakage channel of the temperature element lead wire is effectively blocked, and the oil leakage problem is greatly improved. At the same time, due to the tilted design of the bottom of the junction box, the lubricating oil leaked from other thermal elements at the bottom can be effectively introduced back into the turbine bearing box, thereby maintaining the cleanliness and hygiene of the inside of the junction box.

Description

Technical Field

[0001] The present invention relates to a steam turbine, in particular to a steam turbine instrument signal line sealing structure and a sealing method thereof, belonging to the technical field of mechanical equipment repair. Background Art

[0002] Steam turbines are equipped with numerous temperature measuring elements for monitoring bearing and shoe temperatures. Oil leakage from the bearing housing temperature outlets is a serious problem. This not only results in lubricant loss but also pollutes the on-site environment. Oil stains on equipment and pipelines also increase the risk of fire. In severe cases, this can affect the normal operation of the machinery and prevent safe and civilized production.

[0003] Due to the high-speed rotation of the steam turbine, a large amount of lubricating oil will be thrown onto the surrounding equipment. When the connection surface of the temperature element or other thermal equipment is damaged, the lubricating oil attached to its surface will enter the inside of the element lead wire through the gap at the damaged area. Due to the existence of capillary phenomenon, even if the component installation position is lower than the lead wire outlet hole, the lubricating oil will leak to the outside of the equipment along the lead wire, causing oil leakage.

[0004] The current common treatment for this oil leakage problem involves removing a small section of the protective and shielding layer from the middle of the component lead wire, leaving only the internal component wiring. This approach does not effectively address the capillary effect of oil leakage in the component lead wire. Furthermore, the removal of the protective and shielding layer significantly reduces the component's anti-interference ability, insulation performance, and resistance to external damage. The component lead wire is susceptible to damage and grounding, leading to component damage.

[0005] The joint at the lead-out hole of the component lead wire and the equipment cylinder body are not sealed properly, and there is a gap. When the high-speed rotating turbine throws the lubricating oil over the gap, the lubricating oil will leak through the gap to the outside of the equipment.

[0006] To address the aforementioned leakage, a commonly used method is to wrap raw tape around the threads of the connector to seal the thread gaps. However, this method cannot completely resolve the oil leakage issue, as lubricating oil will slowly leak out from the raw tape used for sealing. If the threaded joint is externally tightened with a nut to achieve a seal, an oil-repellent gasket is typically installed inside the equipment to meet the sealing requirements. This generally meets the sealing requirements, but requires applying significant force to the threaded joint to tighten it, making it more difficult to perform maintenance next time.

[0007] Multiple component lead wires pass through a wire hole at the same time. There are gaps between the lead wires. The lubricating oil thrown to the surrounding area by the turbine will also leak to the outside of the equipment along the gaps between the component lead wires, causing oil leakage.

[0008] To address the oil leakage mentioned above, sealant is usually applied between the lead wires to achieve a sealing effect. However, this treatment method does not provide a good seal deep between the lead wires, and the component wiring cannot be moved after sealing, making subsequent maintenance inconvenient. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a sealing structure and a sealing method for a steam turbine instrument signal line. According to the actual situation on site, a sealing structure and a sealing method are proposed, which effectively solve the technical problem of oil leakage in the steam turbine instrument signal line.

[0010] The technical solution of the present invention is: a sealing structure for instrument signal lines of a steam turbine, which includes a box wall of a steam turbine and an instrument signal line, a signal hole being provided on the box wall, a signal tube being provided in the signal hole, both ends of the signal tube being fixed to the box wall by nuts, the instrument signal line passing through the signal tube and being led out of the box, a junction box 1 being provided on the inner side of the box wall, the junction box 1 being provided with a side box cover 1, the bottom end being arranged at an angle and provided with an oil drain hole, the instrument signal line passing through the side box cover 1 upward at an angle and passing through the signal tube into a junction box 2 fixedly connected to the signal tube, the junction box 2 being provided with a side box cover 2, the instrument line passing through the side box cover 2 of the junction box 2 horizontally to be connected to an external secondary instrument.

[0011] The junction box 1 is fixed to the box wall by nuts, and the signal tube is located on the upper part of the junction box 1.

[0012] The bottom of the second junction box is arranged obliquely and connected to the top of the signal tube.

[0013] The side box cover is connected to the junction box through fasteners. An inclined sleeve is welded on the side box cover. The instrument signal line is located in the sleeve. A conical cavity is provided on the inner side of the bottom end of the sleeve. A sealing ring is provided in the cavity. A locking nut is connected to the outer side of the bottom end of the sleeve through a thread. The sealing ring is compressed and sealed by the locking nut.

[0014] The side box cover 2 is connected to the junction box 2 through fasteners. A horizontally arranged sleeve is welded on the side box cover 2. The instrument signal line is located in the sleeve. A conical cavity is provided on the inner side of the bottom end of the sleeve. A sealing ring is provided in the cavity. A locking nut is connected to the outer side of the bottom end of the sleeve through a thread. The sealing ring is tightened and sealed by the locking nut.

[0015] An oil-resistant rubber sleeve is provided on the instrument signal line, the oil-resistant rubber sleeve is located at the upper side end of the sleeve, and an oil inlet hole is provided on the oil-resistant rubber sleeve.

[0016] The included angle between the sleeve and the side box cover is 30-40 degrees.

[0017] The included angle between the sleeve and the second side box cover is 90 degrees.

[0018] A sealing method for a steam turbine instrument signal line sealing structure comprises the following steps: a signal tube is arranged on a box wall, a junction box 1 and a junction box 2 are respectively arranged at both ends of the signal tube, the junction box 1 is located on the inner side of the box wall, the junction box 2 is located on the outer side of the box wall, the junction box 1 is located lower than the junction box 2, the instrument signal line is obliquely penetrated upward from the junction box 1, passes through the signal tube into the junction box 2, passes horizontally out of the side box cover 2, and is connected to an external secondary instrument, the instrument signal line is effectively sealed by a sealing ring on the side box cover 1, an oil-resistant rubber sleeve is also provided on the instrument signal line, oil vapor will gather on the oil-resistant rubber sleeve and then be collected to the bottom of the junction box 1 through the oil inlet hole, and then be discharged to the inside of the box through the oil drain hole.

[0019] In order to improve the anti-oil seepage effect, under the premise of not affecting the reliability of the equipment, the protective layer and shielding layer of the instrument line can be removed within the range of the oil-resistant rubber sleeve to achieve the correct anti-oil seepage effect.

[0020] The beneficial effects of the present invention are as follows: Compared with the prior art, the technical solution of the present invention, through the use of an improved junction box and improved installation of the temperature element lead wires, solves the problem of oil leakage from the turbine bearing temperature element lead wires. After the modification, the oil leakage channel of the temperature element lead wires is effectively blocked, greatly improving the oil leakage problem. At the same time, the inclined design of the junction box bottom effectively directs lubricating oil leaking from other thermal components at the bottom back into the turbine bearing housing, maintaining the cleanliness and sanitation of the junction box interior and achieving excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 A is a partial enlarged view of the present invention;

[0023] Figure 3 It is a partial enlarged view of B of the present invention. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings.

[0025] Example 1: A sealing structure for a steam turbine instrument signal line, which includes a box wall 8 of a steam turbine and an instrument signal line 6. A signal hole is provided on the box wall 8, and a signal tube 4 is provided in the signal hole. Both ends of the signal tube 4 are fixed to the box wall by nuts 3 (an oil-retaining sealing gasket is installed between the nut 3 and the box wall 8). The instrument signal line 6 passes through the signal tube 4 and is led out of the box. A junction box 2 is provided on the inner side of the box wall 8. The junction box 2 is provided with a side box cover 1, the bottom end of which is arranged at an angle and provided with an oil drain hole 9. The instrument signal line 6 passes through the side box cover 1 upward and passes through the signal tube 4 to enter the junction box 2 7 fixedly connected to the signal tube 4. The junction box 2 7 is provided with a side box cover 2 5. The instrument line passes horizontally through the side box cover 2 5 of the junction box 2 7 to be connected to the external secondary instrument.

[0026] Furthermore, the junction box 2 is fixed to the box wall 8 by nuts 3, and the signal tube 4 is located on the upper part of the junction box 2.

[0027] Furthermore, the bottom of the second junction box 7 is arranged at an angle and connected to the top of the signal tube 4 .

[0028] Furthermore, the side box cover 1 is connected to the junction box 2 through fasteners. An inclined sleeve 13 is welded on the side box cover 1. The instrument signal line 6 is located in the sleeve 13. A conical cavity 16 is provided on the inner side of the bottom end of the sleeve 13. A sealing ring 12 is provided in the cavity 16. A locking nut 11 is connected to the outer side of the bottom end of the sleeve 13 through a thread. The sealing ring 12 is compressed and sealed by the locking nut 11.

[0029] Furthermore, the side box cover 2 5 is connected to the junction box 2 7 through fasteners. A horizontally arranged sleeve 13 is welded on the side box cover 2 5. The instrument signal line 6 is located in the sleeve 13. A conical cavity 16 is provided on the inner side of the bottom end of the sleeve 13. A sealing ring 12 is provided in the cavity 16. A locking nut 11 is threadedly connected to the outer side of the bottom end of the sleeve 13. The sealing ring 12 is tightened and sealed by the locking nut 11.

[0030] Furthermore, an oil-resistant rubber sleeve 15 is provided on the instrument signal line 6 . The oil-resistant rubber sleeve 15 is located at the upper side end of the sleeve 13 . An oil inlet hole 14 is provided on the oil-resistant rubber sleeve 15 .

[0031] Furthermore, the included angle between the sleeve 13 and the side box cover 1 is 30-40 degrees.

[0032] Furthermore, the included angle between the sleeve 13 and the side box cover 2 5 is 90 degrees.

[0033] A sealing method for a steam turbine instrument signal line sealing structure, the method comprising: arranging a signal tube 4 on a box wall 8, with junction box 1 2 and junction box 2 7 respectively arranged at both ends of the signal tube 4, the junction box 1 2 being located on the inner side of the box wall 8, the junction box 2 7 being located on the outer side of the box wall 8, the junction box 1 2 being located lower than the junction box 2 7, the instrument signal line 6 being obliquely penetrated upward from the junction box 1 2, respectively passing through the signal tube 4 into the junction box 2 7, horizontally passing through the side box cover 2 5, and being connected to an external secondary instrument, the instrument signal line 6 being effectively sealed by a sealing ring 12 on the side box cover 1, and an oil-resistant rubber sleeve 15 being further provided on the instrument signal line 6, the oil vapor being gathered on the oil-resistant rubber sleeve 15 and then collected to the bottom of the junction box 1 2 through the oil inlet hole 14, and finally being discharged to the interior of the box through the oil drain hole 9.

[0034] In order to improve the anti-oil seepage effect, under the premise of not affecting the reliability of the equipment, the protective layer and shielding layer of the instrument line can be removed within the range of the oil-resistant rubber sleeve to achieve the correct anti-oil seepage effect.

[0035] By using an improved junction box and revising the installation method for the temperature element lead wires, the problem of oil leakage from the turbine bearing temperature element lead wires has been resolved. After the renovation, the oil leakage channel for the temperature element lead wires has been effectively blocked, significantly improving the oil leakage problem. Furthermore, the inclined design of the junction box bottom effectively directs lubricating oil leaking from other thermal components at the bottom back into the turbine bearing housing, maintaining a clean and hygienic interior of the junction box and achieving excellent performance.

[0036] Furthermore, the sealing method also includes: Method 1, processing one or more places on the temperature lead-out line, selecting a small section of the lead-out line to remove the mesh metal wire and the insulation layer of the shielding layer, and using oil-resistant sealant to seal the lead-out wire inside it, isolating the lubricating oil leakage channel, and achieving the purpose of preventing oil leakage. Finally, a heat shrink tubing is used on the outside for the final packaging to protect the internal sealant and wiring; Method 2, adding an aviation plug at the middle position of the lead-out line, further enhancing the effect of the lead-out line in blocking the oil leakage channel, and facilitating later maintenance (when the thermal engine personnel need to turn over the tiles for maintenance, they do not need to go through the trouble of withdrawing and threading the cables, they only need to disconnect the aviation plug, which greatly improves the maintenance work efficiency).

[0037] Furthermore, the method also includes: processing the seal between the joint and the equipment cylinder body at the wire threading hole of the component lead-out wire. If it is sealed by thread, oil-resistant sealant can be directly applied to the joint thread, and the gap between the threads can be sealed by the sealant to achieve the sealing effect; if the sealing effect is achieved by locking the wire hole joint with a nut on the outside, an oil-resistant sealing gasket can be installed inside the equipment, and the oil stains around it can be cleaned and then a layer of oil-resistant sealant can be applied to meet the sealing requirements.

[0038] Furthermore, the method also includes: if multiple component wires are uniformly passed through a wire hole, a dedicated base is used for installation to achieve physical isolation between the lead wires and eliminate the lubricating oil leakage channel.

[0039] Furthermore, the method also includes: when the internal centralized output lines are isolated externally, when isolating the lead-out lines, it is necessary to use oil-resistant sealing rings to seal and isolate each individual channel, and at the same time, it is also necessary to use sealant at the incoming line end to fully isolate and seal each lead-out line.

[0040] Furthermore, the method also includes: at the head of the turbine, all the lead wires can be concentrated and uniformly led out into a wire threading hole. After being led out, they are bent with large-size galvanized pipes or stainless steel pipes and processed into an "L" shape, and then threaded to ensure that the highest point of the lead wire is much higher than the installation point of the component, so that the height of the oil leakage of the component lead wire will not exceed the highest point of the lead wire, thereby achieving the purpose of blocking oil leakage. In this way, only one leakage point needs to be processed, and all gaps can be blocked by full welding to ensure that there is no oil leakage.

[0041] When bundling the lead wires of thermal components in the bearing box, be careful not to bundle the component wires in places where there may be a lot of oil accumulation; avoid places that may be sprayed with lubricating oil to prevent the wiring from being worn and damaged due to shaking caused by the flushing.

[0042] The wiring bundle fixing point is away from the possible spraying of lubricating oil, and is also higher from the bottom to prevent the lead wires from lying in the oil and reduce the chance of oil leakage.

[0043] Any details not described in detail herein are well known to those skilled in the art. Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention may be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention, and such modifications or equivalents should be encompassed by the claims of the present invention.

Claims

1. A steam turbine instrument signal line sealing structure, comprising a steam turbine casing wall (8) and an instrument signal line (6), characterized in that: The box wall (8) is provided with a signal hole, and a signal tube (4) is provided in the signal hole. Both ends of the signal tube (4) are fixed to the box wall by nuts (3). The instrument signal line (6) passes through the signal tube (4) and is led out of the box. A junction box (2) is provided on the inner side of the box wall (8). The junction box (2) is provided with a side box cover (1). The bottom end is arranged obliquely and provided with an oil drain hole (9). The instrument signal line (6) passes through the side box cover (1) upward and passes through the signal tube (4) to enter the junction box (7) fixedly connected to the signal tube (4). The junction box (7) is provided with a side box cover (5). The instrument line passes horizontally through the side box cover (5) of the junction box (7) and is connected to the external secondary instrument. (7) The bottom is arranged at an angle and connected to the top of the signal tube (4). The side box cover (1) is connected to the junction box (2) through fasteners. A sleeve (13) arranged at an angle is welded on the side box cover (1). The instrument signal line (6) is located in the sleeve (13). A conical cavity (16) is provided on the inner side of the bottom end of the sleeve (13). A sealing ring (12) is provided in the cavity (16). A locking nut (11) is connected to the outer side of the bottom end of the sleeve (13) through a thread. The sealing ring (12) is compressed and sealed by the locking nut (11). An oil-resistant rubber sleeve (15) is provided on the instrument signal line (6). The oil-resistant rubber sleeve (15) is located on the upper side end of the sleeve (13). An oil-introduction hole (14) is provided on the oil-resistant rubber sleeve (15).

2. The steam turbine instrument signal line sealing structure according to claim 1, characterized in that: The junction box 1 (2) is fixed to the box wall (8) by nuts (3), and the signal tube (4) is located on the upper part of the junction box 1 (2).

3. The steam turbine instrument signal line sealing structure according to claim 1, characterized in that The side box cover 2 (5) is connected to the junction box 2 (7) through fasteners. A horizontally arranged sleeve (13) is welded on the side box cover 2 (5). The instrument signal line (6) is located in the sleeve (13). A conical cavity (16) is provided on the inner side of the bottom end of the sleeve (13). A sealing ring (12) is provided in the cavity (16). A locking nut (11) is connected to the outer side of the bottom end of the sleeve (13) through a thread. The sealing ring (12) is pressed and sealed by the locking nut (11).

4. The steam turbine instrument signal line sealing structure according to claim 1, characterized in that: The included angle between the sleeve (13) and the side box cover (1) is 30-40 degrees.

5. The steam turbine instrument signal line sealing structure according to claim 3, characterized in that: The included angle between the sleeve (13) and the second side box cover (5) is 90 degrees.

6. The sealing method for a steam turbine instrument signal line sealing structure according to any one of claims 1 to 5, characterized in that: The method is as follows: a signal tube (4) is arranged on a box wall (8); a junction box 1 (2) and a junction box 2 (7) are respectively arranged at both ends of the signal tube (4); the junction box 1 (2) is located on the inner side of the box wall (8); the junction box 2 (7) is located on the outer side of the box wall (8); the junction box 1 (2) is located lower than the junction box 2 (7); the instrument signal line (6) is obliquely penetrated upward from the junction box 1 (2), penetrates the signal tube (4) and enters the junction box 2 (7), and horizontally penetrates the side box cover 2 (5) to be connected to the external secondary instrument; the instrument signal line (6) is effectively sealed by a sealing ring (12) on the side box cover 1 (1); an oil-resistant rubber sleeve (15) is also provided on the instrument signal line (6); oil vapor will gather on the oil-resistant rubber sleeve (15) and then be collected to the bottom of the junction box 1 (2) through the oil inlet hole (14), and then be discharged to the inside of the box through the oil drain hole (9).

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