Steam leakage sealing device for medium-pressure main steam valve

Abstract

The utility model relates to the technical field of main steam valve sealing, in particular to a medium-pressure main steam valve steam leakage sealing device which comprises a valve seat and a valve clack which are arranged in a valve body, an annular sealing groove matched with the valve clack is formed in the valve seat, a sealing structure is arranged in the annular sealing groove, the sealing structure is formed by splicing a plurality of sealing units, and the sealing units are arranged on the valve seat. The sealing unit comprises an arc section sealing layer and an inner layer seal, and an air cavity is formed in the inner layer seal; and an adjusting assembly. According to the utility model, during installation, when the sealing unit which does not expand is embedded and installed, due to small friction force, the embedded installation is simple, if steam in the valve body is increased, the steam can increase the gas in the gas cavity through the adjusting assembly, so that the sealing unit is further expanded and is more tightly attached to the annular sealing groove, and the sealing effect is better. The actual sealing effect is further improved; and disassembly is easy, on-site replacement and maintenance are facilitated, and the downtime is shortened.

Description

Technical Field

[0001] This utility model relates to the field of main steam valve sealing technology, specifically to a steam leakage sealing device for medium-pressure main steam valve. Background Technology

[0002] Currently, in the field of steam turbines, the most critical sealing area of ​​the medium-pressure main steam valve is located between the valve seat (i.e., the sealing surface inside the valve body) and the valve disc (the closed part of the valve). This sealing surface ensures that there is no steam leakage when the valve is closed.

[0003] However, traditional sealing designs mainly rely on static structures such as sealing rings and gaskets to achieve a sealing effect. During installation, they often rely on large installation pressure or friction, which makes the installation process complex and requires higher precision. If the seal is not installed properly, the sealing effect will be poor, or the sealing components will be displaced during use, causing leakage.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is the closest prior art. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned shortcomings and provide a steam leakage sealing device for the medium-pressure main steam valve.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a steam leakage sealing device for a medium-pressure main steam valve, comprising a valve seat and a valve disc disposed within the valve body, wherein the valve seat is provided with an annular sealing groove adapted to the valve disc, and a sealing structure is provided within the annular sealing groove, wherein the sealing structure is composed of several sealing units spliced ​​together, wherein the sealing unit includes an arc-shaped sealing layer and an inner sealing layer disposed within the arc-shaped sealing layer, and an air cavity is provided inside the inner sealing layer;

[0007] There are two or more adjustment components, which are evenly arranged on the inner sealing end face and communicate with the air cavity. They are used to pressurize gas into the air cavity to adjust the tightness of the connection of the sealing unit in the annular sealing groove.

[0008] Furthermore, the adjustment assembly includes a sleeve correspondingly disposed on the inner sealing end face and communicating with the air cavity, a vent pipe disposed inside the sleeve and close to the air cavity, a spring disposed at the upper end of the vent pipe, a piston block movably disposed at the top of the sleeve and connected to the spring, and a side airbag distributed within the inner sealing layer disposed at one location on the inner wall of the vent pipe.

[0009] Furthermore, the inner sealing layer has several equally spaced splicing circular blocks at one end that is longer than the arc-shaped sealing layer, and an extension plate is provided on the arc-shaped sealing layer at the other end that is longer than the inner sealing layer relative to the splicing circular blocks. The extension plate has several equally spaced splicing circular openings.

[0010] When two adjacent sealing units are spliced ​​together, the splicing circular block and the splicing circular opening on the corresponding side are fixed by a snap fastener.

[0011] Furthermore, the air cavity is grooved along its path within the inner seal.

[0012] Furthermore, the air cavity is connected to several air passages, the same number as the adjustment component, which are vertically distributed and connected to the interior of the ventilation pipe.

[0013] Furthermore, the arc-shaped sealing layer adopts a mechanical seal structure, and the inner layer seal adopts a rubber ring seal structure.

[0014] Compared with the prior art, this utility model has the following beneficial effects: The adjustable component allows for easy installation of the non-expanding sealing unit during insertion due to low friction. If the steam inside the valve body increases, the adjustable component increases the gas volume inside the gas chamber, causing the sealing unit to expand further and fit more tightly with the annular sealing groove, thus further improving the actual sealing effect. Furthermore, the sealing structure, composed of several sealing units, is easy to disassemble, facilitating on-site replacement and maintenance, and reducing downtime. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0016] Figure 1 This is a perspective view of the cross-section of the valve body according to an embodiment of the present invention.

[0017] Figure 2 This is a perspective view of the sealing unit according to an embodiment of the present invention.

[0018] Figure 3 This is an enlarged structural schematic diagram of the adjustment component according to an embodiment of the present invention;

[0019] Figure 4 This is a three-dimensional structural view of an embodiment of the present invention, showing the overall structure of a plurality of sealing units.

[0020] In the diagram: 100, valve body; 101, valve seat; 102, valve disc; 103, annular sealing groove; 200, sealing unit; 1, arc-shaped sealing layer; 2, inner sealing layer; 21, air chamber; 3, adjusting assembly; 31, sleeve; 32, vent pipe; 33, spring; 34, piston block; 35, side airbag; 4, splicing round block; 5, splicing round opening. Detailed Implementation

[0021] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0022] like Figure 1-4 As shown, the steam leakage sealing device for the medium-pressure main steam valve of this utility model includes a valve seat 101 and a valve disc 102 disposed in the valve body 100. The valve seat 101 is provided with an annular sealing groove 103 adapted to the valve disc 102. A sealing structure is provided in the annular sealing groove 103. The sealing structure is composed of several sealing units 200 spliced ​​together. The sealing unit 200 includes an arc-shaped sealing layer 1 and an inner sealing layer 2 disposed inside the arc-shaped sealing layer 1. An air chamber 21 is provided inside the inner sealing layer 2.

[0023] Adjustment components 3, in two or more, are evenly arranged on the end face of the inner sealing layer 2 and communicate with the air cavity 21. They are used to pressurize gas into the air cavity 21 to adjust the tightness of the connection of the sealing unit 200 in the annular sealing groove 103.

[0024] In specific implementation, an annular sealing groove 103 is machined around the end face of the corresponding valve disc 102 on the valve seat 101, and a sealing structure composed of several sealing units 200 is embedded in the annular sealing groove 103. In the initial stage of installation, since the sealing unit 200 has not expanded and the fitting pressure is not large, the friction with the inner wall of the annular sealing groove 103 is small when embedding and installing, and the overall embedding and installation operation is simple.

[0025] Furthermore, the dual sealing design of the arc-shaped sealing layer 1 and the inner sealing layer 2 can improve redundancy, adding an extra layer of sealing to improve the sealing effect;

[0026] Several adjusting components 3 are installed on the end face of the inner sealing layer 2. When the steam inside the valve body 100 increases, the steam will increase the gas inside the gas chamber 21 through the adjusting components 3, causing the sealing unit 200 to expand further and fit more tightly with the annular sealing groove 103, thereby further improving the actual sealing effect.

[0027] It should be noted that the sealing structure, which is composed of several sealing units 200 spliced ​​together, can be easily disassembled, reducing downtime.

[0028] In one embodiment, the adjustment assembly 3 includes a sleeve 31 correspondingly disposed on the end face of the inner seal 2 and communicating with the air chamber 21, and a vent pipe 32 disposed inside the sleeve 31 and close to the air chamber 21. A spring 33 is disposed at the upper end of the vent pipe 32. A piston block 34 connected to the spring 33 is movably disposed at the top of the sleeve 31. A side airbag 35 distributed inside the inner seal 2 is disposed at one location on the inner wall of the vent pipe 32. This design incorporates a hollow sleeve 31 welded to the inner sealing 2 end face, and a vent pipe 32 welded to the lower side of the sleeve 31. The upper end of the vent pipe 32 is fixed to a piston block 34 by a spring 33. When the steam inside the valve body 100 increases, the steam will increase the pressure on the piston block 34, pushing the piston block 34 to move within the sleeve 31. This forces the gas inside the sleeve 31 into the air chamber through the vent pipe 32, and simultaneously, the forced gas enters the side airbag 35, causing the sealing unit 200 to expand further and fit more tightly with the annular sealing groove 103, thus further improving the actual sealing effect.

[0029] Among them, the spring 33 can compress the gas in the sleeve 31 through the vent pipe 32 under the pressure of external force via the piston block 34.

[0030] In one embodiment, the inner sealing layer 2 is provided with a plurality of equally spaced splicing circular blocks 4 at one end longer than the arc segment sealing layer 1, and an extension plate is provided on the arc segment sealing layer 1 at the other end longer than the inner sealing layer 2 relative to the splicing circular blocks 4, and a plurality of equally spaced splicing circular openings 5 ​​are provided on the extension plate;

[0031] When two adjacent sealing units 200 are spliced, the splicing circular blocks 4 and splicing circular openings 5 ​​on the corresponding sides are snapped together. This design, through several equally spaced splicing circular blocks 4 welded to the top surface of one end of the inner sealing layer 2 that is longer than the arc-shaped sealing layer 1, and several equally spaced splicing circular openings 5 ​​machined on the other end of the arc-shaped sealing layer 1 opposite to the splicing circular blocks 4, allows for convenient installation and disassembly of adjacent sealing units 200 after the splicing circular blocks 4 and splicing circular openings 5 ​​on the corresponding sides are snapped together. The entire unit is easy to disassemble, facilitating on-site replacement and maintenance, and reducing downtime.

[0032] In one embodiment, the air cavity 21 is grooved along its path within the inner seal 2. This design, by machining the air cavity 21 within the inner seal 2 and distributing it along the path, ensures uniform gas filling throughout the air cavity 21.

[0033] In one embodiment, the air cavity 21 is connected to several air passages, the same number as the adjusting component 3. These air passages are vertically distributed and communicate with the interior of the vent pipe 32. This design, by machining several air passages connected to the air cavity 21 and machined at the same positions as the adjusting component 3 within the inner seal 2, creates a channel for gas injection between the vent pipe 32 and the air cavity 21.

[0034] In one embodiment, the arc-shaped sealing layer 1 adopts a mechanical seal structure, and the inner seal 2 adopts a rubber ring seal structure. This design allows the mechanical seal structure of the arc-shaped sealing layer 1 to achieve a sealing effect through mechanical compression of the contact surfaces, making it suitable for high-pressure and high-temperature environments. The rubber ring seal structure of the inner seal 2 utilizes elasticity to ensure a seal.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

[0036] It should be noted that if the embodiments of this utility model involve directional indicators, such as up, down, left, right, front, back, etc., the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

Claims

1. A steam leakage sealing device for a medium-pressure main steam valve, comprising a valve seat (101) and a valve disc (102) disposed within a valve body (100), wherein the valve seat (101) is provided with an annular sealing groove (103) adapted to the valve disc (102), and a sealing structure is provided within the annular sealing groove (103), characterized in that: The sealing structure is composed of several sealing units (200) spliced ​​together. The sealing unit (200) includes an arc-shaped sealing layer (1) and an inner sealing layer (2) disposed inside the arc-shaped sealing layer (1). An air cavity (21) is provided inside the inner sealing layer (2). Adjustment components (3), in two or more, are evenly arranged on the end face of the inner seal (2) and communicate with the air cavity (21), for pressurizing gas into the air cavity (21) to adjust the tightness of the connection of the sealing unit (200) in the annular sealing groove (103).

2. The steam leakage sealing device for the medium-pressure main steam valve according to claim 1, characterized in that: The adjustment assembly (3) includes a sleeve (31) correspondingly disposed on the end face of the inner seal (2) and communicating with the air chamber (21), and a vent pipe (32) disposed inside the sleeve (31) and close to the air chamber (21). A spring (33) is disposed at the upper end of the vent pipe (32). A piston block (34) connected to the spring (33) is movably disposed at the top of the sleeve (31). A side airbag (35) distributed inside the inner seal (2) is disposed at one location on the inner wall of the vent pipe (32).

3. The steam leakage sealing device for the medium-pressure main steam valve according to claim 1, characterized in that: The inner sealing layer (2) is provided with several splicing circular blocks (4) at one end longer than the arc segment sealing layer (1), and an extension plate is provided on the arc segment sealing layer (1) at the other end longer than the inner sealing layer (2) relative to the splicing circular blocks (4), and several splicing circular openings (5) at the same interval are provided on the extension plate. When two adjacent sealing units (200) are spliced ​​together, the splicing round block (4) and the splicing round opening (5) on the corresponding side are snapped together.

4. The steam leakage sealing device for the medium-pressure main steam valve according to claim 1, characterized in that: The air cavity (21) is grooved along its path within the inner seal (2).

5. The steam leakage sealing device for the medium-pressure main steam valve according to claim 2, characterized in that: The air chamber (21) is connected to several air passages, the same number as the adjustment component (3), which are vertically distributed and connected to the interior of the vent pipe (32).

6. The steam leakage sealing device for the medium-pressure main steam valve according to claim 1, characterized in that: The arc-shaped sealing layer (1) adopts a mechanical seal structure, and the inner seal (2) adopts a rubber ring seal structure.

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