Special-shaped valve sleeve structure of main throttle valve of steam turbine

Abstract

The utility model discloses a special-shaped valve sleeve structure of a main steam valve of a steam turbine, belongs to the technical field of combined valves of steam turbines, and aims to solve the problem that the maintenance or replacement cost of a left high-pressure main steam adjusting combined valve is extremely high after a valve shoulder is broken. The valve seat body is in a sleeve shape, the periphery of the valve seat body is of a stepped shaft structure, the stepped shaft structure is in sealing fit with a stepped hole spigot of the first steam channel, a vacancy filling flange is arranged at the left end of the valve seat body, the right end face of the vacancy filling flange is matched with the right side wall of the first valve cavity in an abutting mode, and the left end of the vacancy filling flange is in sealing fit with a right end spigot of the rectifying sleeve. When the valve rod slides left and right, the valve clack opens and closes the valve seat body. According to the left high-pressure main steam adjusting combination valve, the vacancy filling flange is matched with the rectifying sleeve, loss caused by breakage of the valve shoulder can be prevented, after the valve shoulder of the left high-pressure main steam adjusting combination valve of the C270 / N300-16.7 / 537 / 537 type turboset is broken, the valve shoulder can be ground to be flat, an adaptive valve seat body is newly machined to maintain the left high-pressure main steam adjusting combination valve, and cost is greatly saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of steam turbine combined valves, and particularly relates to a special-shaped valve sleeve structure of a main steam valve of a steam turbine. Background Art

[0002] The C270 / N300-16.7 / 537 / 537 steam turbine unit is provided with two left and right high-pressure main steam regulating combined valves, wherein the left high-pressure main steam regulating combined valve is composed of a high-pressure main steam valve assembly, a first high-pressure regulating valve assembly and a second high-pressure regulating valve assembly integrated in a combined valve housing. The combined valve housing is provided with a high-pressure main steam valve cavity, the high-pressure main steam valve assembly is installed in the high-pressure main steam valve cavity, the high-pressure main steam valve cavity and the first high-pressure regulating valve cavity are connected through a steam channel, a valve cover is provided at the left end of the combined valve housing, a rectifying sleeve is provided at the right end of the valve cover, the rectifying sleeve extends into the first high-pressure regulating valve cavity, a valve shoulder is provided on the right side wall of the high-pressure main steam valve cavity, the valve shoulder is in the shape of a circular sleeve, the valve shoulder is coaxially arranged with the steam channel, the valve shoulder and the steam channel form a stepped hole, the outer periphery of the cylindrical valve seat is matched with the stop of the stepped hole, and the right end of the rectifying sleeve is matched with the stop of the valve shoulder.

[0003] The valve shoulder is the weak point of the combined valve housing. The force transmission direction between the combined valve housing and the valve seat is uneven. The switching and testing of the valve can easily cause the valve shoulder to break. After the valve shoulder breaks, the cost of repairing or replacing the left high-pressure main steam regulating combined valve is extremely high. Utility Model Content

[0004] The purpose of the utility model is to provide a special-shaped valve sleeve structure of a main steam valve of a steam turbine to solve the problem of extremely high maintenance or replacement costs of the left high-pressure main steam regulating combined valve after the valve shoulder is broken. The technical solution adopted by the utility model is as follows:

[0005] A special-shaped valve sleeve structure of a main steam valve of a steam turbine comprises a valve body, wherein the valve body is provided with a first valve cavity, a second valve cavity and a third valve cavity in sequence from left to right, the right side of the first valve cavity is communicated with the left side of the second valve cavity through a first steam passage, the right side of the second valve cavity is communicated with the left side of the third valve cavity through a second steam passage, a first regulating valve assembly is arranged in the second valve cavity, a second regulating valve assembly is arranged in the third valve cavity, a steam inlet is arranged on the lower side of the first valve cavity, a valve cover is arranged at the left end of the valve body, a guide sleeve and a rectifying sleeve which are connected inside and outside are arranged on the right end surface of the valve cover, a plurality of flow holes are arranged on the rectifying sleeve, a valve stem and an inner hole of the guide sleeve are matched by a packing sliding seal, a valve disc is arranged at the right end of the valve stem, a stepped hole is arranged at the left end of the first steam passage, and the guide sleeve and the rectifying sleeve both extend into the first valve cavity;

[0006] The valve seat body is in the shape of a sleeve, and the outer periphery of the valve seat body is a stepped shaft structure, which is sealed with the stepped hole stop seal of the first steam channel. A gap-filling flange is provided at the left end of the valve seat body, and the right end face of the gap-filling flange abuts against the right side wall of the first valve cavity. The left end of the gap-filling flange is sealed with the right end stop seal of the fairing sleeve. When the valve stem slides left and right, the valve disc opens and closes the valve seat body.

[0007] Furthermore, the inner hole of the valve seat body is a tapered hole that gradually expands from left to right.

[0008] Furthermore, the left end of the inner hole of the valve seat body is a rounded structure, and the rounded structure is sealed with or separated from the valve disc.

[0009] Compared with the prior art, the beneficial effects of the utility model are:

[0010] By matching the gap-filling flange with the fairing sleeve, the loss caused by the breakage of the valve shoulder can be prevented. After the valve shoulder of the existing C270 / N300-16.7 / 537 / 537 steam turbine unit left high-pressure main steam regulating combined valve is broken, the valve shoulder can be smoothed and a new matching valve seat body can be processed to repair the left high-pressure main steam regulating combined valve. The cost of replacing the left high-pressure main steam regulating combined valve of the C270 / N300-16.7 / 537 / 537 steam turbine unit is about 8 million yuan, and the cost of processing the valve seat body is about 300,000 yuan. The utility model greatly saves the cost for the maintenance and overhaul of the left high-pressure main steam regulating combined valve of the C270 / N300-16.7 / 537 / 537 steam turbine unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the utility model;

[0012] Figure 2 yes Figure 1 A partial schematic diagram of the first valve chamber portion;

[0013] Figure 3 It is a structural schematic diagram of the existing left high-pressure main steam regulating combined valve;

[0014] Figure 4 yes Figure 3 A partial schematic diagram of the first valve chamber portion;

[0015] Figure 5 It is a structural diagram of the valve seat body.

[0016] In the figure, 1. valve body, 11. first valve cavity, 12. steam inlet, 13. first steam channel, 2. valve cover, 21. guide sleeve, 22. fairing sleeve, 3. valve stem, 4. valve disc, 5. valve seat body, 51. gap-filling flange, 52. fillet structure, 6. existing valve shell, 63. valve shoulder, 7. existing valve seat. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is described below by specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the utility model. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the utility model.

[0018] The connection mentioned in the present utility model is divided into fixed connection and detachable connection. The fixed connection is a non-detachable connection, including but not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection and welding connection. The detachable connection includes but is not limited to conventional detachable methods such as bolt connection, snap connection, pin connection and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can be found in the existing connection methods to achieve the function, and those skilled in the art can choose according to their needs. For example: choose welding connection for fixed connection and bolt connection for detachable connection.

[0019] The present invention will be further described in detail below in conjunction with the accompanying drawings. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0020] Example: Figure 1-5 As shown, a special-shaped valve sleeve structure of a main steam valve of a steam turbine comprises a valve body 1, wherein the valve body 1 is provided with a first valve chamber 11, a second valve chamber and a third valve chamber in sequence from left to right, the right side of the first valve chamber 11 is communicated with the left side of the second valve chamber through a first steam passage 13, the right side of the second valve chamber is communicated with the left side of the third valve chamber through a second steam passage, the first regulating valve assembly is arranged in the second valve chamber, the second regulating valve assembly is arranged in the third valve chamber, a steam inlet 12 is arranged on the lower side of the first valve chamber 11, a valve cover 2 is arranged at the left end of the valve body 1, a guide sleeve 21 and a flow straightening sleeve 22 which are connected inside and outside are arranged on the right end surface of the valve cover 2, a plurality of flow holes are arranged on the flow straightening sleeve 22, a valve stem 3 and the inner hole of the guide sleeve 21 are matched by a packing sliding seal, a valve disc 4 is arranged at the right end of the valve stem 3, a stepped hole is arranged at the left end of the first steam passage 13, and the guide sleeve 21 and the flow straightening sleeve 22 both extend into the first valve chamber 11;

[0021] The valve seat body 5 is in a sleeve shape, and the outer periphery of the valve seat body 5 is a stepped shaft structure, which is sealed with the stepped hole stopper of the first steam channel 13. A gap-filling flange 51 is provided at the left end of the outer periphery of the valve seat body 5, and the right end face of the gap-filling flange 51 abuts against the right side wall of the first valve cavity 11. The left end of the gap-filling flange 51 is sealed with the right end stopper of the fairing sleeve 22. When the valve stem 3 slides left and right, the valve disc 4 opens and closes the valve seat body 5.

[0022] The inner hole of the valve seat body 5 is a tapered hole that gradually expands from left to right.

[0023] The left end of the inner hole of the valve seat body 5 is a rounded structure 52 , and the rounded structure 52 is sealed with or separated from the valve flap 4 .

[0024] Figure 3 , Figure 4 The structure of the left high-pressure main steam regulating combined valve of the existing C270 / N300-16.7 / 537 / 537 steam turbine unit is provided. The left high-pressure main steam regulating combined valve comprises an existing valve shell 6. The existing valve shell 6 is provided with a fourth valve chamber 61, a second valve chamber and a third valve chamber from left to right in sequence. The right side of the fourth valve chamber 61 is communicated with the left side of the second valve chamber through a first steam passage 13. The right side of the second valve chamber is communicated with the left side of the third valve chamber through a second steam passage. The first regulating valve assembly is arranged in the second valve chamber, the second regulating valve assembly is arranged in the third valve chamber, a steam inlet 12 is arranged on the lower side of the fourth valve chamber 61, a valve cover 2 is arranged at the left end of the existing valve shell 6, and an inner and outer sleeve joint is arranged on the right end surface of the valve cover 2. The guide sleeve 21 and the rectifying sleeve 22 are provided with a plurality of flow holes, the valve stem 3 and the inner hole of the guide sleeve 21 are slidably sealed by the packing, the right end of the valve stem 3 is provided with a valve disc 4, the left end of the first steam channel 13 is provided with a stepped hole, the guide sleeve 21 and the rectifying sleeve 22 both extend into the fourth valve cavity 61; the existing valve seat 7 is in a sleeve shape, the outer periphery of the existing valve seat 7 is a stepped shaft structure, the outer periphery of the existing valve seat 7 is sealed with the stepped hole stop of the first steam channel 13, a valve shoulder 63 is provided on the right side wall of the fourth valve cavity 61, the valve shoulder 63 is a sleeve-shaped structure, the valve shoulder 63 is coaxial with the fourth valve cavity 61, the left end of the valve shoulder 63 is sealed with the right end stop of the rectifying sleeve 22, and when the valve stem 3 slides left and right, the valve disc 4 opens and closes the existing valve seat 7.

[0025] The fourth valve chamber 61 is used as the valve chamber of the high-pressure main steam valve. The high-pressure main steam valve can be formed by installing the valve stem 3, the existing valve seat 7 and other components in the fourth valve chamber 61.

[0026] Figure 5 The structure of the valve seat body 5 is given. Figure 1 and Figure 2The structure of the utility model is shown in FIG. 1 . The utility model grinds and removes the valve shoulder 63 of the existing left high-pressure main steam regulating combined valve of the C270 / N300-16.7 / 537 / 537 steam turbine unit, and adds a gap-filling flange 51 at the left end of the outer periphery of the existing valve seat 7. The remaining technical features are consistent with the existing left high-pressure main steam regulating combined valve of the C270 / N300-16.7 / 537 / 537 steam turbine unit, and are not described in detail here. The gap-filling flange 51 cooperates with the fairing sleeve 22 to prevent the loss caused by the breakage of the valve shoulder 63, and can also be used in the existing C270 / N300-16.7 / 537 / 537 steam turbine unit. After the valve shoulder 63 of the left high-pressure main steam regulating combined valve of the 16.7 / 537 / 537 steam turbine unit is broken, the valve shoulder 63 is ground flat, and a new matching valve seat body 5 is processed to repair the left high-pressure main steam regulating combined valve. The cost of replacing the left high-pressure main steam regulating combined valve of the C270 / N300-16.7 / 537 / 537 steam turbine unit is about 8 million yuan, and the cost of processing the valve seat body 5 is about 300,000 yuan. The utility model greatly saves costs for the maintenance and overhaul of the left high-pressure main steam regulating combined valve of the C270 / N300-16.7 / 537 / 537 steam turbine unit.

[0027] The above embodiments are merely illustrative of the present invention and do not limit its protection scope. Those skilled in the art may also make partial changes thereto, which are within the protection scope of the present invention as long as they do not exceed the spirit of the present invention.

Claims

1. A special-shaped valve sleeve structure for a main steam valve of a steam turbine, comprising a valve body (1), wherein the valve body (1) is provided with a first valve chamber (11), a second valve chamber and a third valve chamber in sequence from left to right, the right side of the first valve chamber (11) is connected to the left side of the second valve chamber through a first steam passage (13), the right side of the second valve chamber is connected to the left side of the third valve chamber through a second steam passage, a first regulating valve assembly is arranged in the second valve chamber, a second regulating valve assembly is arranged in the third valve chamber, and the first valve chamber (11) is connected to the left side of the second valve chamber through a second steam passage. A steam inlet (12) is provided at the lower side, a valve cover (2) is provided at the left end of the valve body (1), a guide sleeve (21) and a flow-rectifying sleeve (22) are provided on the right end surface of the valve cover (2) and are connected inside and outside, a plurality of flow holes are provided on the flow-rectifying sleeve (22), a valve stem (3) and an inner hole of the guide sleeve (21) are slidably sealed by a packing, a valve flap (4) is provided at the right end of the valve stem (3), a stepped hole is provided at the left end of the first steam passage (13), and the guide sleeve (21) and the flow-rectifying sleeve (22) both extend into the first valve chamber (11); Features: The valve seat body (5) is in the shape of a sleeve, and the outer periphery of the valve seat body (5) is a stepped shaft structure, and the stepped shaft structure is sealed with the stepped hole stop of the first steam channel (13). The left end of the valve seat body (5) is provided with a gap-filling flange (51), and the right end surface of the gap-filling flange (51) is abutted against the right side wall of the first valve cavity (11). The left end of the gap-filling flange (51) is sealed with the right end stop of the fairing sleeve (22). When the valve stem (3) slides left and right, the valve disc (4) opens and closes the valve seat body (5).

2. The special-shaped valve sleeve structure of the main steam valve of a steam turbine according to claim 1, characterized in that: The inner hole of the valve seat body (5) is a tapered hole that gradually expands from left to right.

3. A turbine main steam valve special-shaped valve sleeve structure according to claim 2, characterized in that: The left end of the inner hole of the valve seat body (5) is a rounded structure (52), and the rounded structure (52) is sealed with or separated from the valve flap (4).

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