Steam turbine shaft seal heat insulation device
By using threaded fasteners for the turbine shaft seal and threaded fasteners for the insulation plate to form a closed heat insulation space, the problem of temperature difference caused by steam ejection in the turbine shaft seal is solved, and the sealing performance of the shaft seal is improved.
Patent Information
- Application Number
- CN202520819108.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-27
- Publication Date
- 2026-02-06
- Estimated Expiration
- 2035-04-27
AI Technical Summary
Excessive temperature differences caused by steam ejection at the turbine shaft seal lead to internal deformation of the seal, reducing its airtightness. Existing measures cannot effectively solve the leakage problem.
By using threaded fasteners for the shaft seal and threaded fasteners for the heat insulation plate, a closed heat insulation space is formed, reducing heat exchange between the outside air and the shaft seal chamber and ensuring uniform shaft seal temperature.
It effectively reduces the cooling effect of steam on the shaft seal chamber, making the shaft seal temperature uniform, reducing stress caused by temperature differences, and improving the sealing performance of the shaft seal.
Smart Images
Figure CN223881246U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to steam turbine field especially relates to a steam turbine shaft seal heat insulating device. BACKGROUND
[0002] In nuclear power plant, steam turbine is needed to convert steam into kinetic energy and then into electric energy. Since the first single-shaft, three-cylinder (one high-pressure cylinder and two low-pressure cylinders), four-steam-exhaust, impulse condensing half-speed steam turbine unit was installed and debugged, the unit has occurred multiple times of steam leakage at the middle split surface of the high-pressure steam exhaust end shaft seal of the high-pressure cylinder. During the first cylinder opening overhauling, the bolt pre-tightening torque near the leakage point was increased from 6080 N.m to 9200 N.m, and sealing grease was applied on the sealing surface, but the problem could not be solved effectively. After the unit was started, steam leakage still occurred successively. The site has carried out multiple pressure leakage stoppage, but the leakage could not be avoided. Investigation found that the steam sprayed from the steam turbine had a cooling effect on the shaft seal chamber, which made the temperature of the outer circle of the shaft seal much lower than that of the inner circle. The large temperature difference caused great stress in the shaft seal, which deformed the shaft seal and reduced the air tightness. SUMMARY
[0003] The utility model wants to solve the technical problem in providing a steam turbine shaft seal heat insulating device.
[0004] The utility model adopts the technical scheme that the shaft seal threaded fastener is used for sealing the rotating shaft of the steam turbine threaded fastener, and the heat insulation plate threaded fastener is used for wrapping the shaft seal threaded fastener. The shaft seal threaded fastener includes a plurality of recessed shaft seal chamber threaded fasteners, which are arranged around the shaft seal threaded fastener. A plurality of heat insulation plate threaded fasteners are covered on a plurality of shaft seal chamber threaded fasteners and are attached to the side wall. The heat insulation plate threaded fastener and the shaft seal chamber threaded fastener jointly form a closed heat insulation space to reduce the heat exchange between the external air and the shaft seal chamber.
[0005] In some embodiments, the heat insulation plate threaded fastener includes a plurality of detachably connected sub-plates, which are connected to each other at the head and tail to wrap the shaft seal threaded fastener.
[0006] In some embodiments, the sub-plate includes at least two plate segments of different shapes, and the total circumference of all the plate segments matches the circumferential length of the shaft seal.
[0007] In some embodiments, the sub-plate includes a long plate and a short plate, and the circumference of the long plate is twice that of the short plate.
[0008] In some embodiments, the sub-plate is provided with first connecting part threaded fasteners protruding away from the shaft seal threaded fastener at both ends, the first connecting part threaded fasteners at the connection of adjacent sub-plates abut each other, and the abutting faces of the first connecting part threaded fasteners are provided with first threaded holes, and adjacent two first connecting part threaded fasteners are connected and fixed by threaded fasteners passing through the first threaded holes.
[0009] In some embodiments, the heat insulation plate is nested in the shaft seal cavity and connected with the side wall of the shaft seal cavity by interference fit or clearance fit.
[0010] In some embodiments, the abutting position of the heat insulation plate threaded fastener is provided with second connecting part threaded fasteners protruding away from the shaft seal threaded fastener, the second connecting part threaded fasteners are provided with second threaded holes, and the second connecting part threaded fasteners and the shaft seal cavity threaded fasteners are connected and fixed by threaded fasteners passing through the second threaded holes.
[0011] In some embodiments, the abutting position of the heat insulation plate and the side wall of the shaft seal cavity is provided with a plurality of welding points.
[0012] In some embodiments, a plurality of heat insulation plates are arranged in the middle part of the shaft seal and away from the steam turbine end.
[0013] In some embodiments, the heat insulation plate is provided with a heat insulation layer close to one side of the shaft seal.
[0014] The steam turbine shaft seal heat insulation device has the following beneficial effects: the steam sprayed by the steam turbine can cool the shaft seal cavity, the corresponding heat insulation plate is installed at the shaft seal cavity, direct contact of the steam with the shaft seal cavity is avoided, the cooling effect of the steam on the shaft seal cavity is effectively reduced, the overall temperature of the shaft seal is relatively uniform, the stress generated by the shaft seal due to excessive temperature difference is reduced, and the sealing performance of the shaft seal is improved. BRIEF DESCRIPTION OF DRAWINGS
[0015] In order to more clearly illustrate the technical scheme of the present application, the present application will be further described below in conjunction with the drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor. In the drawings:
[0016] Figure 1 is a whole view of a steam turbine shaft seal heat insulation device in an embodiment of the present application;
[0017] Figure 2It is a side view of a steam turbine shaft seal heat insulation device in an embodiment of the utility model;
[0018] Figure 3 It is a partial enlarged view of a steam turbine shaft seal heat insulation device in an embodiment of the utility model;
[0019] Figure 4 It is a partial sectional view of a steam turbine shaft seal heat insulation device in an embodiment of the utility model.
[0020] Reference signs
[0021] 100, steam turbine; 110, shaft seal; 120, shaft seal chamber; 200, heat insulation plate; 210, long plate; 220, short plate; 230, first connecting part; 240, second connecting part. DETAILED DESCRIPTION
[0022] In order to have a clearer understanding of the technical features, purposes and effects of the utility model, the specific embodiments of the utility model will be described in detail with reference to the drawings. In the following description, it should be understood that the orientation or position relationship indicated by "upper", "inner", "outer", etc. is based on the orientation or position relationship shown in the drawings, and is constructed and operated in a particular orientation, and is only for the convenience of describing the technical scheme, and does not indicate that the device or element indicated must have a particular orientation, so it cannot be understood as a limitation on the utility model.
[0023] It should also be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "fixing", "setting", etc. should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; It can be mechanically connected, or it can be electrically connected; It can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship of two elements. When an element is referred to as "on" or "below" another element, the element can be "directly" or "indirectly" located on the other element, or there can be one or more intervening elements. The terms "first", "second", "third", etc. are only for the convenience of describing the technical scheme, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features with "first", "second", "third", etc. can be explicitly or implicitly included one or more features. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.
[0024] Figures 1 to 4 Some preferred embodiments of the utility model are shown. The steam turbine shaft seal heat insulation device can be used to isolate the steam contact of the shaft seal chamber 120 of the steam turbine 100.
[0025] Figures 1 to 4 The steam turbine shaft seal heat insulation device shown in an embodiment of the utility model, it can include for the steam turbine 100's rotating shaft is sealed shaft seal 110 and for the shaft seal 110 is wrapped heat insulation plate 200, the shaft seal 110 includes several recessed shaft seal chamber 120, the shaft seal chamber 120 is arranged around the shaft seal 110, several heat insulation plate 200 is covered on several shaft seal chamber 120 and is attached with side wall, the heat insulation plate 200 and the shaft seal chamber 120 jointly form closed heat insulation space to reduce the heat exchange between external air and the shaft seal chamber 120.
[0026] The steam turbine 100's spouting steam can cool the shaft seal chamber 120 of shaft seal 110, installs corresponding heat insulation plate 200 at shaft seal chamber 120, can avoid steam directly with shaft seal chamber 120 contact, effectively reduces the cooling effect of steam on shaft seal chamber 120, makes the overall temperature of shaft seal 110 relatively uniform, thereby reducing the stress of shaft seal 110 due to excessive temperature difference, improves the sealing performance of shaft seal 110.
[0027] It can be understood that the shape of shaft seal 110 is generally cylindrical, the shaft seal chamber 120 is arranged around the shaft seal 110, and the number of shaft seal chamber 120 is set according to the actual design requirements of steam turbine 100.
[0028] It can be understood that the shaft seal 110 can be other shapes, such as cuboid, and the shape of the heat insulation plate 200 needs to be changed according to the shape of the shaft seal 110.
[0029] Figure 1 And Figure 3 The heat insulation plate 200 shown in an embodiment can include several detachable sub-plates, and the sub-plates are connected to each other to wrap the shaft seal 110. The shape of the sub-plate connected to the end is the same as that of the shaft seal chamber 120, and the sub-plate is sleeved in the shaft seal chamber 120, which can completely seal the shaft seal chamber 120.
[0030] It can be understood that the sub-plate can be separately arranged in the shaft seal chamber 120 without necessarily being connected to each other.
[0031] Figure 1 And Figure 3 The sub-plate shown in an embodiment can include at least two different shaped plate segments, and the total circumference of all the plate segments matches the circumferential length of the shaft seal 110. The different shaped plate segments are adapted to the shape of the shaft seal chamber 120 for easy installation.
[0032] It can be understood that the sub-plate includes a long plate 210 and a short plate 220, and the shape and length of the long plate 210 and the short plate 220 are matched with the shaft seal chamber 120 of the steam turbine 100.
[0033] In a specific embodiment, the shaft seal chamber 120 is a separate chamber, and the sub-plate can be sealed by selecting different long plates 210 or short plates 220 according to the shaft seal chamber 120.
[0034] Figure 1 And Figure 3 It is shown that in an embodiment, the sub-plate can include that the sub-plate includes a long plate 210 and a short plate 220, and the arc length of the long plate 210 is twice that of the short plate 220. The long plate 210 and the short plate 220 are combined to form a circle that communicates with the outer circle of the shaft seal chamber 120.
[0035] In a specific embodiment, the long plate 210 is connected with two short plates 220 at both ends through the first connecting part 230, and the unfolded length of the long plate 210 is twice that of the short plate 220.
[0036] Further, the two short plates 220 are away from the two ends of the long plate 210 without the first connecting part 230, because there is interference with the shaft seal 110, and the avoidance is performed.
[0037] Figure 1 And Figure 3 It is shown that in an embodiment, the sub-plate can include that the first connecting part 230 is provided at both ends of the sub-plate and protrudes away from the shaft seal 110, the first connecting parts 230 at the connecting positions of adjacent sub-plates abut each other, a plurality of first threaded holes are provided on the abutment surface of the first connecting part 230, and the adjacent two first connecting parts 230 are connected and fixed by a threaded fastener passing through the first threaded holes. The first connecting part 230 of the sub-plate connected end to end is connected and fixed by the threaded fastener, and the threaded fastener is convenient to connect, disassemble and install.
[0038] In a specific embodiment, an elastic gasket is arranged at the abutment position of the first connecting parts 230 of the adjacent two sub-plates to compensate for the gap caused by the thermal expansion deformation of the sub-plate.
[0039] Further, the first connecting part 230 extends away from the shaft seal chamber 120 to form a sheet shape, and the first connecting part 230 can be bent, and after the two first connecting parts are connected, the gap can be compensated by being folded into a triangular shape.
[0040] Further, the adjacent two first connecting parts 230 can be fixed by welding.
[0041] It can be understood that the number of first connecting portions 230 is set according to the width dimension of the heat insulation plate 200 and the bonding strength of the first connecting portions 230.
[0042] Further, the abutting positions of the plurality of adjacent first connecting portions 230 are each provided with an elastic gasket.
[0043] Figure 1 and Figure 3 It is shown that the heat insulation plate 200 and the shaft seal chamber 120 can be connected in an embodiment by nesting the heat insulation plate 200 in the shaft seal chamber 120 and connecting the side wall of the shaft seal chamber 120 through interference fit or clearance fit, so as to seal the heat insulation plate 200 and the shaft seal chamber 120.
[0044] In a specific embodiment, the gap between the heat insulation plate 200 and the shaft seal chamber 120 can be filled with a heat insulation material for sealing, such as glass fiber, asbestos, etc.
[0045] Figure 3 and Figure 4 It is shown that the heat insulation plate 200 can include a plurality of second connecting portions 240 protruding away from the shaft seal 110 at the abutting position of the heat insulation plate 200 in an embodiment, the second connecting portions 240 are provided with a plurality of second threaded holes, and the second connecting portions 240 are connected and fixed with the shaft seal chamber 120 through threaded fasteners passing through the second threaded holes. The side wall of the shaft seal chamber 120 is also processed with corresponding second threaded holes, which can effectively connect the second connecting portions 240 and the side wall of the shaft seal chamber 120 firmly.
[0046] In a specific embodiment, the second connecting portions can be welded on the shaft seal by welding, reducing the processing of the second threaded holes.
[0047] Figure 1 and Figure 3 It is shown that the heat insulation plate 200 and the shaft seal chamber 120 can include a plurality of welding points at the abutting position of the heat insulation plate 200 and the side wall of the shaft seal chamber 120 in an embodiment. The connection strength of the heat insulation plate 200 and the shaft seal chamber 120 is improved, the threaded fasteners are prevented from loosening, and the service life is effectively improved.
[0048] In a specific embodiment, each heat insulation plate has at least three welding points, which are respectively arranged at both ends and the middle of the heat insulation plate, and the three welding points make the shape of the heat insulation plate more fit the shaft seal chamber 120.
[0049] In a specific embodiment, the welding adopts argon arc welding, so that the heat insulation plate and the shaft seal are melted and adhered together.
[0050] Figure 3 and Figure 4It is shown that the shaft seal 110 can include several heat insulation plates 200 arranged in the middle of the shaft seal 110 and away from one end of the steam turbine 100 in an embodiment. Because the temperature near the steam turbine 100 is higher than that of the other end, the steam is also more difficult to be directly injected near the steam turbine 100.
[0051] It can be understood that the shaft seal is installed on one side of the steam turbine, and the shaft seal exchanges heat with the steam turbine, and the temperature near the steam turbine is higher than that of the other end.
[0052] Figure 1 And Figure 4 Figure 1 Figure 2 It is shown that the heat insulation plate 200 can include a heat insulation layer arranged on the side of the heat insulation plate 200 close to the shaft seal 110 in an embodiment. The heat insulation layer is formed by using a material with high heat insulation performance, and effectively insulates the heat exchange between the steam and the shaft seal cavity 120.
[0053] In a specific embodiment, a heat insulation coating can be added on the side of the heat insulation plate 200 close to the shaft seal, and the heat insulation coating is a reflective heat insulation coating. The reflective heat insulation coating is obtained by adding superfine porous materials, hollow glass or ceramic microbeads in the coating, and by selecting appropriate resins, metals, or metal oxide colors, fillers and production processes to obtain a high reflectivity coating, which reflects heat radiation to achieve the purpose of heat insulation.
[0054] It can be understood that the above embodiments only express the preferred embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the present application patent; It should be pointed out that for ordinary skilled in the art, the above technical features can be freely combined without departing from the concept of the present application, and some deformations and improvements can be made, which belong to the protection scope of the present application; Therefore, any equivalent transformation and modification within the scope of the claims of the present application shall belong to the scope of the claims of the present application.
Claims
1. A steam turbine shaft seal heat insulation device, characterized in that, include: A shaft seal (110) for sealing the shaft of a steam turbine (100) and a heat insulation plate (200) for wrapping the shaft seal (110); The shaft seal (110) includes a plurality of recessed shaft seal chambers (120) arranged around the shaft seal (110). A plurality of heat insulation plates (200) cover the plurality of shaft seal chambers (120) and are attached to the side walls. The heat insulation plates (200) and the shaft seal chambers (120) together form a closed heat insulation space to reduce heat exchange between the outside air and the shaft seal chambers (120).
2. The turbine shaft seal heat insulation device according to claim 1, characterized in that, The heat insulation plate (200) includes several detachably connected sub-plates, which are connected end to end to wrap around the shaft seal (110).
3. The turbine shaft seal heat insulation device according to claim 2, characterized in that, The subplate comprises at least two different shapes of plate segments, and the total perimeter of all the plate segments matches the circumferential length of the shaft seal (110).
4. A turbine shaft seal heat insulation device according to claim 3, characterized in that... The sub-plate includes a long plate (210) and a short plate (220), wherein the perimeter of the long plate (210) is twice that of the short plate (220).
5. A turbine shaft seal heat insulation device according to claim 2, characterized in that, The sub-plate has a first connecting part (230) at both ends that protrudes away from the shaft seal (110). The first connecting parts (230) at the connection of adjacent sub-plates abut against each other. The abutting surface of the first connecting part (230) is provided with a plurality of first threaded holes. Two adjacent first connecting parts (230) are connected and fixed by threaded fasteners passing through the first threaded holes.
6. A turbine shaft seal heat insulation device according to claim 2, characterized in that, The heat insulation plate (200) is nested inside the shaft sealing chamber (120) and is connected to the side wall of the shaft sealing chamber (120) by interference fit or clearance fit.
7. A turbine shaft seal heat insulation device according to claim 6, characterized in that, The heat insulation plate (200) has a plurality of second connecting portions (240) protruding away from the shaft seal (110) at the abutment. The second connecting portions (240) are provided with a plurality of second threaded holes. The second connecting portions (240) and the shaft seal chamber (120) are connected and fixed by threaded fasteners passing through the second threaded holes.
8. A turbine shaft seal heat insulation device according to claim 1, characterized in that, The heat insulation plate (200) and the side wall of the shaft sealing chamber (120) are provided with several welding points.
9. A turbine shaft seal heat insulation device according to claim 1, characterized in that, Several of the heat insulation plates (200) are disposed in the middle of the shaft seal (110) and at the end away from the turbine (100).
10. A turbine shaft seal heat insulation device according to claim 1, characterized in that, The heat insulation plate (200) has a heat insulation layer on the side near the shaft seal (110).