Double-layer valve cover of main steam inlet valve of steam turbine

Abstract

The utility model discloses a double-layer valve cover of a main steam inlet valve of a steam turbine, which comprises an outer valve cover and a valve body shell in sealing connection with an inner thread of the outer valve cover, a limiting inner pressing ring with an outer thread surface is arranged in the outer valve cover, and a sealing gasket for sealing the inside of the valve body shell is inserted into the bottom of the limiting inner pressing ring. After the outer valve cover and the valve body shell are locked and sealed, the limiting inner pressing ring penetrates through the valve body shell to press the sealing gasket on the sealing convex ring arranged in the inner valve cover through the sealing pressing plate, so that the sealing gasket can be sealed and pressed in the inner valve cover more firmly, and as long as the outer valve cover and the valve body shell are not loosened, the sealing gasket can not be loosened. Therefore, the density gasket is always kept in a sealed state, the phenomenon that the density gasket loosens and rubs with the inner wall of the valve body shell is avoided, and the sealing effect of the double-layer valve cover of the main steam inlet valve of the steam turbine is further improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of steam turbines, and in particular relates to a double-layer valve cover of a main steam inlet valve of a steam turbine. Background Art

[0002] A steam turbine is a type of turbine machinery used to convert gas thermal energy into mechanical work. A steam turbine is a thermal turbine that uses steam as a working fluid and converts steam thermal energy into mechanical work. As the primary thermal prime mover, steam turbines play an extremely important role in various sectors of the national economy, including energy, electricity, and power engineering, as well as in national defense. Currently, the double-layer bonnets of most existing steam turbine main steam inlet valves are fixed with bolts, which can easily tilt at the joints. The large number of bolts can also damage the bonnets. Furthermore, the internal sealing gaskets of the bonnets are mostly made of rubber, which can reduce their sealing properties after long-term use, gradually weakening the sealing effect of the seals.

[0003] When the cam is in the closed position, the cam is in the closed position, and the cam is in the closed position, so that the cam is in the closed position and the cam is in the closed position.

[0004] However, for the double-layer valve cover of the above-mentioned turbine main steam inlet valve, although the spring is slidably sleeved on the positioning rod, and the positioning rod is slidably connected to the inside of the positioning groove, the positioning rod is slidably connected to the inside of the positioning groove to limit the spring, thereby preventing the spring from bending and breaking after long-term use. However, the following more obvious defects still exist during use: However, the spring sleeve is used to fix the sealing gasket when the valve cover and the valve are connected. However, since the sealing gasket uses the spring sleeve, the gas in the valve body will surge outward, causing the sealing gasket to continuously rub against the inner wall of the valve body, thereby causing a larger gap between the edge of the sealing gasket and the inner wall of the valve body, and then the problem of weakened sealing between the sealing gasket and the inner wall of the valve body occurs. Utility Model Content

[0005] The purpose of the utility model is to provide a double-layer valve cover for a main steam inlet valve of a steam turbine, so as to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a double-layer valve cover for a main steam inlet valve of a steam turbine, comprising an outer valve cover and a valve body shell connected to the inner thread of the outer valve cover in a sealing manner, the outer valve cover is provided with a limiting inner pressure ring with an external threaded surface, the bottom of the limiting inner pressure ring is plugged and installed with a sealing gasket for sealing the inside of the valve body shell, the bottom of the valve body shell is provided with an inner valve cover, the end of the inner valve cover is provided with a support ring portion extending outward, the end side of the support ring portion is provided with an outer limiting ring member threadedly connected to the lower end of the valve body shell, the inner wall of the inner valve cover is provided with a sealing convex ring extending inward and sealingly fitting with the sealing gasket, the end of the outer valve cover is provided with a screwing handle which is convenient for screwing the outer valve cover, and the end of the sealing gasket is provided with a sealing pressure plate which keeps the sealing gasket unchanged during the pressing and sealing.

[0007] Preferably, a locking cavity for threaded installation of the valve body shell and the outer valve cover is provided between the inner wall of the outer valve cover and the limiting inner pressure ring, so that the valve body shell and the outer valve cover can be quickly connected by threads.

[0008] Preferably, an annular sealing groove is provided at the top of the inner portion of the locking cavity, and a locking sealing rubber ring is provided in the annular sealing groove to achieve the function of sealing the joint between the valve body shell and the outer valve cover after locking.

[0009] Preferably, a sealing protrusion ring is provided around the side of the end of the valve body shell, which extends upward and seals tightly with the annular sealing groove, thereby ensuring a better sealing effect of the threaded combination of the valve body shell and the outer valve cover.

[0010] Preferably, the end side of the sealing pressure plate is provided with an annular limiting groove for limiting, pressing and sealing with the limiting inner pressure ring, so as to achieve compression of the sealing gasket and enhance the sealing performance after the outer valve cover is locked.

[0011] Preferably, the bottom of the limiting inner pressure ring extends downward to be provided with a crimping protrusion ring for crimping and limiting with the annular limiting groove, thereby achieving sealing and pressing on the inner side of the valve body shell to ensure that the problem of reduced sealing performance will not occur in the later stage.

[0012] The closure of the closure is sealed by the spring which is fixed to the closure by the cam and the camming member is fixed to the closure by means of the camming member and the camming member is fixed to the closure by means of the camming member.

[0013] Through the locking cavity formed between the inner cavity of the outer valve cover and the limiting inner pressure ring, and the combination of the annular magic cube groove and the locking sealing rubber ring in the locking cavity, after the valve body shell is locked with the outer valve cover, the sealing protrusion ring is inserted into the annular sealing groove while locking, and the sealing protrusion ring is pressed tightly in the locking sealing rubber ring through the locking force, so that the connection between the valve body shell and the outer valve cover can also maintain sealing, avoiding the problem of rust and corrosion at the connection causing reduced sealing. Through the setting of two sealing structures, the valve cover of the main steam inlet valve of the turbine is better sealed, and there will be no sealing attenuation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural diagram of the utility model;

[0015] Figure 2 This is a schematic diagram of the exploded structure of the valve cover of the utility model;

[0016] Figure 3 This is a schematic diagram of the structure of the outer valve cover of the utility model when viewed from above.

[0017] In the figure: 1. Outer valve cover; 2. Valve body shell; 3. Limit inner pressure ring; 4. Sealing gasket; 5. Inner valve cover; 6. Support ring; 7. Outer limit ring; 8. Sealing convex ring; 9. Screw handle; 10. Sealing pressure plate; 11. Locking cavity; 12. Annular sealing groove; 13. Locking sealing rubber ring; 14. Sealing convex ring; 15. Annular limit groove; 16. Crimp convex ring. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] See also Figure 1-3 The bottom of the valve body shell 2 is provided with an inner valve cover 5 to realize the connection between the bottom of the valve body shell 2 and the inner valve cover 1.

[0020] The end of the inner valve cover 5 is extended outward to provide a support ring portion 6, which is used to support the bottom of the valve body shell 2 after locking. The side of the end of the support ring portion 6 is provided with an outer limit ring 7 threadedly connected to the lower end of the valve body shell 2, so that the support ring portion 6 and the outer limit ring 7 are integrated, so that the sealing performance is better. The inner wall of the inner valve cover 5 is provided with a sealing convex ring 8 extending inward and sealingly fitting with the sealing gasket 4 to achieve sealing between the valve body shell 2 and the outer valve cover 1 after locking. The end of the outer valve cover 1 is provided with a screwing handle 9 which is conducive to screwing the outer valve cover 1 to achieve installation and disassembly of the outer valve cover 1. The end of the sealing gasket 4 is provided with a sealing pressure plate 10 that keeps the sealing gasket 4 unchanged during the press-fit seal, ensuring that the sealing gasket 4 is completely fitted on the end of the sealing convex ring 8.

[0021] A locking chamber 11 is provided between the inner wall of the outer valve cover 1 and the limiting inner pressure ring 3, which allows the valve body shell 2 and the outer valve cover 1 to be threadedly installed, which is beneficial to the locking connection between the valve body shell 2 and the outer valve cover 1. An annular sealing groove 12 is provided at the top end of the locking chamber 11, which allows the valve body shell 2 to be limited after being locked. A locking sealing rubber ring 13 is provided in the annular sealing groove 12, which allows the valve body shell 2 to be locked and sealed after being locked, thereby ensuring the sealing between the two. A sealing protrusion ring 14 is provided around the side of the end of the valve body shell 2, which extends upward and is tightly sealed with the annular sealing groove 12, thereby ensuring the sealing between the main steam valve and the outer valve cover 1.

[0022] The end side of the sealing pressure plate 10 is provided with an annular limiting groove 15 for limiting, pressing and sealing with the limiting inner pressure ring 3, so that the limiting inner pressure ring 3 can press and seal the sealing pressure plate 10 combination. The bottom of the limiting inner pressure ring 3 extends downward to be provided with a crimping protrusion ring 16 for crimping and limiting with the annular limiting groove 15, so that the limiting inner pressure ring 3 can be locked inside the valve body shell 2 and then extend into the inner valve cover 5 to press the sealing pressure plate 10 to ensure its sealing.

[0023] Specifically, when in use, first screw the handle 9 to make the outer valve cover 1 and the valve body shell 2 threadedly fixed in the locking cavity 11, and the sealing protrusion ring 14 at the upper end of the valve body shell 2 is pressed tightly against the locking sealing rubber ring 13 in the annular sealing groove 12, which can ensure the sealing between the outer valve cover 1 and the valve body shell 2 without the phenomenon of sealing attenuation. After the upper end of the valve body shell 2 is fixed inside the locking cavity 11, the setting of the limiting inner pressure ring 3 plays a limiting and fixing role in the connection between the outer valve cover 1 and the valve body shell 2, avoiding the phenomenon of thread rotation deflection during connection, and continuing to screw the handle 9 to make the valve body shell 2 2 bottom is connected to the inner side of the outer limiting ring 7 by means of a threaded rotation. The limiting inner pressure ring 3 extends to the interior of the valve body shell 2 and the inner valve cover 5, which can limit and fix the connection between the inner valve cover 5 and the valve body shell 2. At the same time, the limiting inner pressure ring 3 presses the sealing pressure plate 10 against the end of the sealing convex ring 8 while the outer valve cover 1 is locked, so that the sealing pressure plate 10 presses the sealing gasket 4 against the end of the sealing convex ring 8 firmly, thereby increasing the sealing firmness of the sealing gasket 4 between the inner valve cover 5 and the valve body shell 2, and avoiding the phenomenon of reduced sealing performance caused by friction with the inner wall of the inner valve cover 5 after long-term use.

[0024] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A double-layer bonnet for a main steam inlet valve of a steam turbine, comprising an outer bonnet (1) and a valve body shell (2) connected to the outer bonnet (1) by an internal threaded seal, characterized in that: The outer valve cover (1) is provided with a limiting inner pressure ring (3) with an external threaded surface, and a sealing gasket (4) for sealing the valve body shell (2) is installed at the bottom of the limiting inner pressure ring (3), and an inner valve cover (5) is provided at the bottom of the valve body shell (2), and a support ring portion (6) is extended outward from the end of the inner valve cover (5), and an outer limiting ring (7) is provided on the side of the end of the support ring portion (6) and is threadedly connected to the lower end of the valve body shell (2), and a sealing convex ring (8) is provided around the inner wall of the inner valve cover (5) and extends inward and fits and seals with the sealing gasket (4), and a screwing handle (9) is provided at the end of the outer valve cover (1) for screwing the outer valve cover (1), and a sealing pressure plate (10) is provided at the end of the sealing gasket (4) to prevent the sealing gasket (4) from being deformed during the press-fit sealing.

2. The double-layer bonnet of a steam turbine main steam inlet valve according to claim 1, characterized in that: A locking cavity (11) for threadedly mounting the valve body shell (2) and the outer valve cover (1) is provided between the inner wall of the outer valve cover (1) and the limiting inner pressure ring (3).

3. The double-layer bonnet of a main steam inlet valve of a steam turbine according to claim 2, characterized in that: An annular sealing groove (12) is provided at the top end of the locking cavity (11), and a locking sealing rubber ring (13) is provided in the annular sealing groove (12).

4. The double-layer bonnet of a main steam inlet valve of a steam turbine according to claim 1, characterized in that: A sealing protrusion ring (14) is provided around the side of the end of the valve body shell (2) and extends upwards and is tightly sealed with the annular sealing groove (12).

5. The double-layer bonnet of a steam turbine main steam inlet valve according to claim 1, characterized in that: An annular limiting groove (15) for limiting, pressing and sealing with the limiting inner pressure ring (3) is provided on the end side of the sealing pressure plate (10).

6. The double-layer bonnet of a steam turbine main steam inlet valve according to claim 5, characterized in that: The bottom of the limiting inner pressure ring (3) is downwardly extended to be provided with a pressing protrusion ring (16) for performing pressure connection and combination limiting with the annular limiting groove (15).

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