A sealing structure for the end face of a movable guide vane of a water turbine

Abstract

The present invention discloses a turbine movable guide vane end face sealing structure, the end face sealing structure comprises an upper end face seal arranged on the upper end top cover of the movable guide vane and a lower end face seal arranged on the lower end bottom ring of the movable guide vane, wherein the upper end face seal and / or the lower end face seal are respectively provided with an end face sealing portion; through the structural design of the end face sealing portion in the movable guide vane end face sealing structure, the degree of compression between the action surface of the end face sealing block and the upper and lower end faces of the movable guide vane in the end face sealing structure can be adjusted based on the pressure adjustable medium input through the pipeline. Thus, even after the unit has been in operation for several years, the problem that the amount of water leakage at the guide vane end face seal increases year by year during the unit maintenance due to the wear of mud and sand at the end face sealing block and the aging of the rubber of the end face sealing strip is avoided, as in the traditional sealing structure.

Description

Technical Field

[0001] The invention belongs to the technical field of water turbine component sealing, and in particular relates to a water turbine movable guide vane end face sealing structure. Background Art

[0002] The movable guide vanes of the hydro-turbine generator set are fully closed. When the unit is shut down, the outside of the movable guide vanes is filled with pressurized water. The higher the operating head of the unit, the greater the water pressure on the outside. After the unit is shut down, in order to facilitate maintenance, there are strict quantitative requirements for the leakage of the end and vertical surfaces of the movable guide vanes. In order to reduce the leakage of the movable guide vanes, the hydro-turbine generator set generally has end face seals on the upper and lower end faces of the movable guide vanes. The upper and lower end face seals are respectively closed on the top cover and the bottom ring. Due to the installation position of the end face seal, it can only be replaced when the unit is overhauled (in the industry, the general unit needs to be overhauled for a period of 10 years or more, that is, a major overhaul every 10 years). Therefore, the movable guide vane end face seal must have reliable sealing performance, especially for high head and ultra-large mixed flow units. It is necessary to design a new sealing structure to enhance the sealing performance of the guide vane end face.

[0003] In the prior art: the traditional structural scheme of the movable guide vane end face seal of the hydro-generator set, see Figure 1 The conventional end face sealing structure 100 of the movable guide vane mainly includes three parts: end face sealing strip 108, end face sealing block 109, and sealing pressure plate 107. The end face sealing strip 108 is a solid structure made of rubber. When the end face sealing 109 is in a free state, the extrusion plane 110 (action surface) of the end face sealing block 109 is higher than the flow plane of the top cover and the bottom ring by h (see Figure 1 ), during the closing process of the movable guide vane, when the upper and lower end faces of the guide vane sweep the end face sealing block 109, the upper and lower end faces of the guide vane squeeze the sealing block action surface upward and downward respectively, and the end face sealing block 109 compresses the end face sealing strip 108. The end face sealing strip 108 relies on its own elasticity to press the end face sealing block 109 action surface and the upper and lower end faces of the guide vane to achieve the purpose of sealing the pressure water of the guide vane end face. After the unit has been running for several years, due to the wear of mud and sand at the end face sealing block 109 and the aging of the rubber of the end face sealing strip 108, the water leakage at the end face seal will increase year by year, affecting the maintenance work of the unit. Summary of the invention

[0004] In order to overcome the problems of the prior art, a turbine movable guide vane end face sealing structure is provided, in which the degree of compression between the end face sealing action surface and the upper and lower end faces of the movable guide vane is adjustable, so as to ensure the sealing performance and service life of the end face seal within an overhaul period of the unit (i.e. ≥10 years).

[0005] The object of the present invention is achieved through the following technical solutions:

[0006] A turbine movable guide vane end face sealing structure, the end face sealing structure comprises an upper end face seal arranged on a top cover at an upper end of the movable guide vane and a lower end face seal on a bottom ring at a lower end of the movable guide vane, wherein the upper end face seal and / or the lower end face seal are respectively provided with an end face sealing portion; the end face sealing portion comprises: two sealing pressure plates, the sealing pressure plates are fixed on the top cover or the bottom ring, and a clamping groove structure is formed between the two sealing pressure plates; an end face sealing block, the end face sealing block is clamped in the clamping groove, and one end of the end face sealing block extends out of the clamping groove structure and can move toward the movable guide vane; an end face sealing strip, the end face sealing strip is made of a flexible material and is arranged against the end face sealing block; a pipeline, one end of the pipeline is connected to a pressure-adjustable medium input end, and the other end is connected to the top cover or the bottom ring and is in conduction with the end face sealing strip, and the position adjustment of the end face sealing block, that is, the adjustment of the sealing compression degree, is completed through the input of the medium.

[0007] Through the structural design of the end face sealing part in the movable guide vane end face sealing structure, the degree of compression between the action surface of the end face sealing block and the upper and lower end faces of the movable guide vane in the end face sealing structure can be adjusted based on the pressure-adjustable medium input through the pipeline. Therefore, even after the unit has been in operation for several years, the problem of increasing water leakage at the end face seal year by year due to sand wear at the end face sealing block and aging of the rubber of the end face sealing strip in the traditional sealing structure is avoided.

[0008] According to a preferred embodiment, the surface of the end face sealing block on the side of the end face sealing strip is a planar structure or is provided with a groove structure. Through the structural design of the surface of the end face sealing block on the side of the end face sealing strip, the end face sealing block can be applied to a variety of end face sealing strips that match it.

[0009] According to a preferred embodiment, the end face sealing strip is a hollow end face sealing strip or a solid end face sealing strip.

[0010] According to a preferred embodiment, the bottom end of the hollow end face sealing strip abuts against the end face sealing block, a hollow cavity structure is provided therein, and the cavity is in communication with the pipeline.

[0011] According to a preferred embodiment, the top of the solid end face sealing strip is provided with a protrusion matching the groove on the end face sealing block, the bottom of the solid end face sealing strip is provided with a groove-like structure, and the groove of the groove-like structure is in conduction with the pipeline.

[0012] According to a preferred embodiment, the surface of the sealing pressure plate is in the same plane as the flow plane of the top cover or the bottom ring.

[0013] According to a preferred embodiment, the sealing pressure plate is pre-tightened and fastened to the top cover or the bottom ring by bolts.

[0014] According to a preferred embodiment, the end face sealing strip is made of rubber material.

[0015] According to a preferred embodiment, sealing grooves are provided on both sides of the solid end face sealing strip, and the solid end face sealing strip is pressed by a sealing pressing plate.

[0016] The aforementioned main scheme of the present invention and its further options can be freely combined to form multiple schemes, all of which are schemes that can be adopted and claimed for protection by the present invention; and in the present invention, (non-conflicting options) options and other options can also be freely combined. After understanding the scheme of the present invention, those skilled in the art can understand that there are many combinations based on the prior art and common knowledge, all of which are technical schemes to be protected by the present invention, and they are not exhaustively listed here.

[0017] Beneficial effects of the present invention: Through the structural design of the end face sealing part in the movable guide vane end face sealing structure, the degree of compression between the working surface of the end face sealing block and the upper and lower end faces of the movable guide vane in the end face sealing structure can be adjusted based on the pressure-adjustable medium input through the pipeline. Therefore, even after the unit has been in operation for several years, the problem of increasing water leakage at the end face seal year by year due to the wear of mud and sand at the end face sealing block and the aging of the rubber of the end face sealing strip in the traditional sealing structure is avoided. The design concept of adjustable compression of the movable guide vane end face seal presented in the present invention broadens the structural design type of the end face seal, which not only enhances the sealing performance and applicability of the end face seal, but also prolongs the service life of the end face seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a traditional end face sealing structure;

[0019] Figure 2 is a schematic diagram of the end face sealing structure corresponding to embodiment 1 of the present invention;

[0020] Figure 3 is an enlarged schematic diagram of the end face sealing portion A in the end face sealing structure corresponding to Example 1 of the present invention;

[0021] Figure 4 is a schematic diagram of the end face sealing structure corresponding to embodiment 2 of the present invention;

[0022] Figure 5 is an enlarged schematic diagram of the end face sealing portion B in the end face sealing structure corresponding to Example 2 of the present invention;

[0023] Among them, 100-traditional end face sealing structure, 101-movable guide vane, 102-top cover, 103-upper end face seal, 104-bottom ring, 105-lower section seal, 106-flow plane of top cover or bottom ring, 107-sealing pressure plate, 108-end face sealing strip, 109-end face sealing block, 110-extrusion plane, 201-movable guide vane, 202-top cover, 203-upper end face seal, 204-pipeline, 205-bottom ring, 2 ...111-movable guide vane, 112-top cover, 113-top end face seal, 114-pipeline, 115-bottom ring, 116-bottom section seal, 117-bottom section seal, 118-bottom section seal, 119-bottom section seal, 120-bottom section seal, 121-bottom section seal, 122-bottom section seal, 123-bottom section seal, 124-bottom section seal, 125-bottom section seal, 126-bottom section seal, 127-bottom section seal, 128-bottom section seal, 129-bottom section seal, 6-lower end face seal, A-end face sealing part, 207-flow plane, 208-sealing pressure plate, 209-hollow end face sealing strip, 210-end face sealing block, 301-movable guide vane, 302-top cover, 303-upper end face seal, 304-pipeline, 305-bottom ring, 306-lower end face seal, B-end face sealing part, 307-flow plane, 308-sealing pressure plate, 309-solid end face sealing strip, 310-end face sealing block. DETAILED DESCRIPTION

[0024] The following non-limiting examples serve to illustrate the invention.

[0025] Embodiment 1:

[0026] refer to Figure 2 and Figure 3 As shown, the figure shows a turbine movable guide vane end face sealing structure.

[0027] The end face sealing structure includes an upper end face seal 203 provided on the top cover 202 at the upper end of the movable guide vane 201 and a lower end face seal 206 provided on the bottom ring 205 at the lower end of the movable guide vane 201. The upper end face seal 203 and / or the lower end face seal 206 are respectively provided with an end face sealing portion A. The end face sealing portion A completes the sealing of the movable guide vane 201.

[0028] Preferably, the end face sealing part A comprises: two sealing pressure plates 208, an end face sealing block 210, an end face sealing strip and a pipeline 204. The pressure plate 208 is used to complete the fixed position limitation of the end face sealing block 210 to prevent the end face from being separated from the end face sealing part A. The end face sealing block 210 completes the sealing of the movable guide vane through the plane in contact with the movable guide vane 201. The end face sealing strip is used to complete the position adjustment of the end face sealing block 210 to ensure the sealing effect of the end face sealing block 210. The pipeline 204 is used to pass a pressure-adjustable medium into the end face sealing part A to deform the end face sealing strip, thereby pushing the end face sealing block 210 to have a tendency to move toward the movable guide vane to complete the sealing of the movable guide vane.

[0029] Preferably, the sealing pressure plate 208 is fixed on the top cover 202 or the bottom ring 205 , and a slot structure is formed between the two sealing pressure plates 208 to complete the engagement with the end face sealing block 210 .

[0030] Furthermore, the surface of the sealing plate 208 is located in the same plane as the flow plane 207 of the top cover 202 or the bottom ring 205. The sealing plate 208 is pre-tightened and fastened to the top cover 202 or the bottom ring 205 by bolts.

[0031] Preferably, the end face sealing block 210 is clamped in the clamping groove, and one end thereof protrudes out of the clamping groove structure, so as to seal the movable guide vane 201 via the protruding end.

[0032] Furthermore, the surface of the end face sealing block 210 on the side of the end face sealing strip is a planar structure. Through the structural design of the surface of the end face sealing block 210 on the side of the end face sealing strip, the end face sealing block 210 can be applied to the end face sealing strip matched therewith.

[0033] Preferably, the end face sealing strip is made of a flexible material and is arranged against the end face sealing block 210 , so as to realize the pushing movement of the end face sealing block 210 through the deformation of the end face sealing strip, so that the end face sealing block 210 has a tendency to move toward the movable guide vane 201 .

[0034] Further, the end face sealing strip is a hollow end face sealing strip 209. The bottom end of the hollow end face sealing strip 209 abuts against the end face sealing block 210. The hollow end face sealing strip 209 is provided with a hollow cavity structure therein, and the cavity is in communication with the pipeline 204, so that the pressure adjustable medium introduced into the pipeline 204 can be input into the cavity, so that the end face sealing body 209 expands and deforms.

[0035] Preferably, one end of the pipeline 204 is connected to a pressure-adjustable medium input end, and the other end is connected to the top cover 202 or the bottom ring 205 and communicates with the end face sealing strip. The position of the end face sealing block 210 is adjusted by the input of the medium.

[0036] Furthermore, the end face sealing block 210 and / or the end face sealing strip are made of rubber material.

[0037] Thus, through the structural design of the end face sealing portion A in the movable guide vane end face sealing structure, the degree of compression between the action surface of the end face sealing block 210 and the upper and lower end faces of the movable guide vane 201 in the end face sealing structure can be adjusted based on the pressure adjustable medium input through the pipeline 204. Therefore, even after the unit has been in operation for several years, the problem of increasing water leakage at the end face seal year by year due to sand wear at the end face sealing block 210 and aging of the rubber of the end face sealing strip in the traditional sealing structure is avoided.

[0038] Example 2

[0039] On the basis of Example 1, Figure 4 and Figure 5 As shown, the end face sealing structure may also be an end face sealing portion B provided on the upper end face sealing 303 and / or the lower end face sealing 306. The end face sealing portion B is used to seal the guide vane 301.

[0040] Preferably, the end face sealing portion B includes: two sealing pressure plates 308 , an end face sealing block 310 , an end face sealing strip and a pipeline 304 .

[0041] Preferably, the end face sealing block 310 is snap-fitted into the slot, and one end of the end face sealing block 310 extends out of the slot structure.

[0042] Furthermore, the end face sealing block 310 is provided with a groove structure on the surface of the end face sealing strip side. Through the structural design of the end face sealing block 310 on the surface of the end face sealing strip side, the end face sealing block 310 can be better matched and connected with the end face sealing strip.

[0043] Preferably, the end face sealing strip is made of a flexible material and is disposed against the end face sealing block 310 , and the end face sealing strip is a solid end face sealing strip 309 .

[0044] Furthermore, the top of the solid end face sealing strip 309 is provided with a protrusion matching the groove on the end face sealing block 310 to complete the matching connection with the end face sealing block 310. At the same time, the bottom of the solid end face sealing strip 309 is provided with a slot-shaped structure, and the slot of the slot-shaped structure is connected with the pipeline 304. So that the pressure adjustable medium introduced into the pipeline 304 is input into the slot, so that the end face sealing strip 309 expands and deforms. Thus, the end face sealing block 310 is pushed up to complete the sealing of the movable guide vane 301.

[0045] The above basic examples of the present invention and their further selected examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed by the present invention. In the scheme of the present invention, each selected example can be arbitrarily combined with any other basic example and selected example. Those skilled in the art will know that there are many combinations.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A turbine movable guide vane end face sealing structure, characterized in that: The end face sealing structure comprises an upper end face seal arranged on the top cover of the upper end of the movable guide vane and a lower end face seal arranged on the bottom ring of the lower end of the movable guide vane, wherein the upper end face seal and / or the lower end face seal are respectively provided with an end face sealing portion; The end face sealing portion comprises: Two sealing pressure plates, the sealing pressure plates are fixed on the top cover or the bottom ring, and a slot structure is formed between the two sealing pressure plates; An end face sealing block, wherein the end face sealing block is clamped in the clamping groove, and one end of the end face sealing block extends out of the clamping groove structure and can move toward the direction of the movable guide vane; An end face sealing strip, which is made of a flexible material and is arranged against the end face sealing block; A pipeline, one end of which is connected to a pressure-adjustable medium input end, and the other end is connected to the top cover or the bottom ring and is connected to the end face sealing strip, so that the position of the end face sealing block, i.e., the degree of sealing compression, is adjusted by the input of the medium; The surface of the end face sealing block on the side of the end face sealing strip is a planar structure or is provided with a groove structure; The end face sealing strip is a hollow end face sealing strip or a solid end face sealing strip; The top end of the hollow end face sealing strip abuts against the end face sealing block, and a hollow cavity structure is provided inside the hollow end face sealing strip, and the cavity is in communication with the pipeline; The top of the solid end face sealing strip is provided with a protrusion matching the groove on the end face sealing block, and the bottom of the solid end face sealing strip is provided with a groove-shaped structure, and the groove of the groove-shaped structure is in conduction with the pipeline; The surface of the sealing pressure plate is located in the same plane as the flow plane of the top cover or the bottom ring.

2. A turbine movable guide vane end face sealing structure as claimed in claim 1, characterized in that: The sealing pressure plate is pre-tightened by bolts and is fastened to the top cover or the bottom ring.

3. A turbine movable guide vane end face sealing structure as claimed in claim 1, characterized in that: The end face sealing strip is made of rubber material.

4. A turbine movable guide vane end face sealing structure as claimed in claim 1, characterized in that: Sealing grooves are arranged on both sides of the solid end face sealing strip, and the sealing strips in the sealing grooves are pressed tightly by sealing pressing plates.

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