A steam turbine control valve and a steam turbine

Abstract

The present application relates to the technical field of thermal power steam turbines, and in particular to a steam turbine regulating valve and a steam turbine, which includes a valve stem inserted between a valve body and a valve cover, the upper part of the valve stem is rotatably connected to the valve cover and a guide sleeve, the lower part of the valve stem extends into the inner cavity of the guide sleeve and a clamp is installed on its lower end surface; the lower part of the valve stem is sleeved with a valve sleeve, the outer peripheral wall of the valve sleeve is tightly abutted against the inner peripheral wall of the guide sleeve, and a gap is left between the inner peripheral wall of the valve sleeve and the outer peripheral wall of the valve stem; the bottom end of the valve sleeve is provided with an annular clamping platform overlapped with the clamping head, and multiple groups of balancing holes are evenly distributed on the upper circumference of the annular clamping platform, and the tangent direction of each group of balancing holes at any interval has an angle with the horizontal direction; the outer cover of the annular clamping platform is provided with a valve shell with a connecting hole at the bottom, the clamping head is located between the valve shell and the annular clamping platform, and there is a movable margin along the axis direction of the valve stem. The present application can make the regulating valve more tightly closed when it is closed, reducing the possibility of gas leakage.

Description

Technical Field

[0001] This application relates to the technical field of thermal power steam turbines, and particularly relates to a steam turbine control valve and a steam turbine. Background Art

[0002] A steam turbine is a rotary steam power device and is the most widely used prime mover in modern thermal power plants. Its principle is to control the steam inlet volume by adjusting the opening degree of the control valves distributed on both sides of the steam turbine. The steam throttled by the control valves blows the blades on the steam turbine rotor to make the rotor rotate, so as to drive the generator rotor to rotate and generate electric energy.

[0003] In a thermal power steam turbine control valve, the valve stem of the control valve is connected to the piston rod of the oil actuator, so that the oil actuator transmits through the valve stem to the valve disc to adjust the opening degree of the control valve, and further adjust the steam turbine load; a main balance hole is axially opened along the axis of the valve core at the bottom surface of the valve core of the control valve, and a secondary balance hole is vertically penetrated along the axis direction of the valve core at one end of the valve core close to the valve stem. A valve sleeve is sleeved outside the valve core of the control valve, and a gap is left between the inner peripheral wall of the valve sleeve and the outer peripheral wall of the valve core. The main balance hole, the secondary balance hole, and the gap between the valve sleeve and the valve core are kept in communication, and the valve core realizes the pressure difference balance between the valve stem cavity and the intake passage and the exhaust passage through the main balance hole, the secondary balance hole, and the gap between the valve sleeve and the valve core.

[0004] In the related art, when the control valve is in the closed state, due to the existence of a relatively large gap between the valve sleeve and the valve core, at this time, the high-temperature and high-pressure steam will leak to the secondary balance hole through the gap between the valve sleeve and the valve core, and then leak to the main balance hole through the secondary balance hole, and finally enter the cylinder. That is, in this state, the control valve is not tightly closed and the gas leakage amount is relatively large. Summary of the Invention

[0005] In order to solve some or all of the above technical problems, this application provides a steam turbine control valve and a steam turbine, which can make the control valve more tightly closed in the closed state and reduce the possibility of gas leakage.

[0006] According to a first aspect of the present invention, a steam turbine regulating valve is provided, which includes a valve body with an open top and a valve cover installed at the opening of the valve body. A valve cavity is provided in the valve body, and the valve cavity includes an intake passage, an exhaust passage that are connected to each other, and a valve seat disposed in the middle of the valve cavity. A guide sleeve coaxial with the valve seat is also installed on the inner peripheral wall at the open top of the valve body; a valve rod passes through between the valve body and the valve cover. The upper part of the valve rod is rotatably connected to both the valve cover and the guide sleeve. The lower part of the valve rod extends into the inner cavity of the guide sleeve, and a chuck is installed on the lower end surface thereof; a valve sleeve is also sleeved on the lower part of the valve rod. The outer peripheral wall of the valve sleeve is in close contact with the inner peripheral wall of the guide sleeve, and a gap is left between the inner peripheral wall of the valve sleeve and the outer peripheral wall of the valve rod; a ring-shaped clamping platform that is lapped and cooperated with the chuck is also provided at the bottom end of the valve sleeve. A plurality of groups of balance holes are evenly distributed along the circumferential direction of the ring-shaped clamping platform. The tangential direction at any interval of each group of balance holes forms an angle with the horizontal direction; a valve housing with a communication hole opened at the bottom is also covered outside the ring-shaped clamping platform. The chuck is located between the valve housing and the ring-shaped clamping platform and has a movement margin along the axial direction of the valve rod. When the bottom of the chuck disengages from the valve housing, the inner cavity of the guide sleeve, the balance holes, and the communication hole are kept in communication with each other.

[0007] By adopting the above technical solution, when it is necessary to close the regulating valve, the piston rod of the oil motor drives the valve rod to rotate in the valve cover and the guide sleeve, so that the valve rod moves towards the direction close to the valve seat. At the same time, the valve rod drives the valve sleeve and the valve housing to move towards the direction close to the valve seat synchronously through the lapping cooperation between the chuck and the ring-shaped clamping platform. During the whole process, the chuck is always in contact with the bottom end of the ring-shaped clamping platform. That is, in this state, the inner cavity of the guide sleeve, the balance holes, the communication hole, the intake passage, and the exhaust passage are in a communicating state until the valve housing abuts against the valve seat for sealing. At this time, the upper part of the chuck disengages from the ring-shaped clamping platform, and the lower part of the chuck abuts against the inner bottom wall of the valve housing for sealing, and the intake passage and the exhaust passage are in a non-communicating state, and the regulating valve is closed;

[0008] When it is necessary to open the regulating valve, the piston rod of the oil motor drives the valve rod to rotate in the valve cover and the guide sleeve, so that the valve rod moves towards the direction away from the valve seat. At the same time, the valve rod drives the valve sleeve and the valve housing to move towards the direction away from the valve seat synchronously through the lapping cooperation between the chuck and the ring-shaped clamping platform. During this process, when the bottom of the chuck disengages from the valve housing until the upper part of the chuck abuts against the bottom end of the ring-shaped clamping platform and the valve housing disengages from the valve seat, the intake passage and the exhaust passage are in communication, and the regulating valve is opened;

[0009] That is, when the regulating valve is in the closed state, since the lower part of the chuck abuts against the inner bottom wall of the valve housing for sealing, in this state, the intake passage and the exhaust passage are in a non-communicating state (closed state), that is, the inner cavity of the guide sleeve, the balance holes, and the communication hole are in a non-communicating state (closed state). Therefore, it is basically impossible for high-temperature and high-pressure steam to leak into the cylinder, making the regulating valve more tightly sealed in the closed state.

[0010] Further, the chuck includes a first clamping portion directly connected to the valve stem and a second clamping portion connected to the first clamping portion. Among them, the end of the first clamping portion away from the valve stem is flared, and the outer peripheral wall of the first clamping portion is a smooth inclined plane; the end of the second clamping portion away from the first clamping portion is constricted, and the outer peripheral wall of the second clamping portion is a smooth arc surface; it should be noted that when the balance hole and the communication hole at the bottom of the valve housing are not in a communicating state, the outer peripheral wall of the second clamping portion abuts against the inner bottom wall of the valve housing for sealing.

[0011] By adopting the above technical solution, during use, the valve stem drives the valve sleeve and the valve housing to reciprocate through the chuck. When the balance hole and the communication hole at the bottom of the valve housing are in a communicating state, the outer peripheral wall of the first clamping portion abuts against the bottom of the annular clamping platform for sealing; when the balance hole and the communication hole at the bottom of the valve housing are not in a communicating state, the outer peripheral wall of the second clamping portion abuts against the inner bottom wall of the valve housing for sealing.

[0012] Further, the end of the annular clamping platform close to the chuck has a lapping portion that lappingly cooperates with the chuck. Specifically, the lapping portion includes an inclined annular abutting surface and a horizontally arranged annular transition surface directly connected to the annular abutting surface; it should be noted that when the balance hole and the communication hole at the bottom of the valve housing are in a communicating state, the annular abutting surface closely abuts against the inclined plane of the outer peripheral wall of the first clamping portion.

[0013] By adopting the above technical solution, the inclined annular abutting surface cooperates with the inclined plane of the outer peripheral wall of the first clamping portion. Specifically, when the balance hole and the communication hole at the bottom of the valve housing are in a communicating state, that is, this state is a critical state (the regulating valve is in an open state or the regulating valve is in a closed state but the bottom of the chuck has not yet abutted against the inner bottom wall of the valve housing for sealing). In this critical state, the inclined annular abutting surface closely abuts against the inclined plane of the outer peripheral wall of the first clamping portion.

[0014] Further, there is a gap between the inner peripheral wall of the annular clamping platform and the outer peripheral wall of the valve stem. One end of the balance hole extends to the gap between the annular clamping platform and the valve stem, and the other end extends to the annular transition surface of the lapping portion.

[0015] By adopting the above technical solution, one end of the balance hole extends to the gap between the annular clamping platform and the valve stem, and the other end extends to the annular transition surface of the lapping portion, which also defines the setting direction of the balance hole in the annular clamping platform (inclined setting state). That is, in this state, the balance hole is connected to the inner cavity of the guide sleeve through the gap between the annular clamping platform and the valve stem. This way of arranging the through hole is also easier during actual hole opening.

[0016] Further, a lapping groove is circumferentially formed on the inner peripheral wall of the valve seat near the end close to the guide sleeve. When the intake passage and the exhaust passage are not in a communicating state, the outer peripheral wall of the valve housing abuts against the lapping groove for sealing.

[0017] By adopting the above technical solution, when the intake passage and the exhaust passage are in a non-connected state, that is, in this state, the regulating valve is in a closed state. In this state, the outer peripheral wall of the valve housing abuts and seals against the lapping groove.

[0018] Furthermore, the first clamping portion and the second clamping portion are of an integrally formed structure, and the connection between the first clamping portion and the second clamping portion has a smooth transition.

[0019] By adopting the above technical solution, the first clamping portion and the second clamping portion are of an integrally formed structure, making the connection strength between the first clamping portion and the second clamping portion higher, the integrity stronger, and the firmness higher.

[0020] Furthermore, the connection manner between the valve housing and the annular clamping platform is bolt connection, threaded connection or snap connection.

[0021] By adopting the above technical solution, the connection manner between the valve housing and the annular clamping platform is bolt connection, threaded connection or snap connection, enabling the valve housing to be conveniently disassembled and assembled with the annular clamping platform, which is convenient for actual use.

[0022] Furthermore, the annular clamping platform and the valve sleeve are of an integrally formed structure.

[0023] By adopting the above technical solution, the annular clamping platform and the valve sleeve are of an integrally formed structure, making the connection strength between the two higher, the integrity stronger, and the firmness higher.

[0024] According to the second aspect of the present invention, a steam turbine is provided, which includes the steam turbine regulating valve as described in the first aspect of the present invention.

[0025] As can be seen from the above technical solution, in the steam turbine regulating valve described in the first aspect of the present invention and the steam turbine described in the second aspect of the present invention, when the regulating valve is in the closed state, since the lower part of the chuck abuts and seals against the inner bottom wall of the valve housing, in this state, the intake passage and the exhaust passage are in a non-connected state (closed state), that is, the inner cavity of the guide sleeve, the balance hole and the communication hole are in a non-connected state (closed state). Therefore, there is basically no possibility of high-temperature and high-pressure steam leaking into the cylinder, making the regulating valve more tightly closed in the closed state.

[0026] In addition, the steam turbine regulating valve of the present invention also has the advantages of simple structure, easy assembly, safe and reliable use, and is convenient for implementation, popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0028] Figure 1 is a schematic structural diagram of a steam turbine regulating valve according to an embodiment of the present invention;

[0029] Figure 2 is Figure 1 a partial enlarged schematic view of part A in

[0030] Figure 3 is a schematic structural diagram showing the bottom of the first clamping part abutted and sealed against the inner bottom wall of the valve housing;

[0031] Figure 4 is Figure 3 a partial enlarged schematic view of part B in

[0032] Figure 5 is a partial schematic structural diagram showing the balance hole.

[0033] Explanation of reference numerals: 1, valve body; 11, valve cavity; 111, intake passage; 112, exhaust passage; 113, valve seat; 1131, lapping groove; 2, valve cover; 3, guide sleeve; 4, valve stem; 5, chuck; 51, first clamping part; 52, second clamping part; 6, valve sleeve; 7, annular clamping platform; 71, balance hole; 72, lapping part; 721, annular abutting surface; 722, annular transition surface; 8, valve housing; 81, communication hole. Specific embodiments

[0034] The following will Figures 1-5 further elaborate on the present application in detail.

[0035] As Figures 1-3 shown, an embodiment of the present invention provides a steam turbine regulating valve. The regulating valve includes a valve body 1 with an open top and a valve cover 2 installed at the opening of the valve body 1. The connection method between the valve cover 2 and the valve body 1 is bolt connection; a valve cavity 11 is provided in the valve body 1. The valve cavity 11 includes an intake passage 111, an exhaust passage 112 that are connected to each other, and a valve seat 113 installed in the middle of the valve cavity 11. A guide sleeve 3 coaxial with the valve seat 113 is also installed on the inner peripheral wall at the top opening of the valve body 1, and there is a distance between the end of the guide sleeve 3 and the valve seat 113.

[0036] As Figures 1-3As shown, in this embodiment, a valve stem 4 is passed through between a valve body 1 and a valve cover 2. The upper part of the valve stem 4 is rotatably connected to both the valve cover 2 and a guide sleeve 3. The lower part of the valve stem 4 extends into the inner cavity of the guide sleeve 3 and a chuck 5 is installed on the lower end face thereof; the chuck 5 includes a first chuck portion 51 directly connected to the valve stem 4 and a second chuck portion 52 connected to the first chuck portion 51; wherein, the first chuck portion 51 and the second chuck portion 52 are of an integrally formed structure, and the connection part between the first chuck portion 51 and the second chuck portion 52 has a smooth transition; the end of the first chuck portion 51 away from the valve stem 4 is in a flared shape, and the outer peripheral wall of the first chuck portion 51 is a smooth inclined plane; the end of the second chuck portion 52 away from the first chuck portion 51 is in a constricted shape, and the outer peripheral wall of the second chuck portion 52 is a smooth arc surface.

[0037] As Figure 3 and Figure 4 shown, in this embodiment, a valve sleeve 6 is further sleeved on the lower part of the valve stem 4. The outer peripheral wall of the valve sleeve 6 is in close contact with the inner peripheral wall of the guide sleeve 3, and there is a gap between the inner peripheral wall of the valve sleeve 6 and the outer peripheral wall of the valve stem 4; an annular clamping platform 7 that is integrally formed with the valve sleeve 6 and is in lap joint with the chuck 5 is further provided at the bottom end of the valve sleeve 6, and a valve housing 8 with a communication hole 81 opened at the bottom is further sleeved outside the annular clamping platform 7; wherein, the connection mode between the valve housing 8 and the annular clamping platform 7 is bolt connection, screw connection or snap connection, but it is preferably bolt connection; there is a gap between the inner peripheral wall of the annular clamping platform 7 and the outer peripheral wall of the valve stem 4, and a plurality of groups of balance holes 71 as Figure 5 shown are evenly distributed along the circumferential direction of the annular clamping platform 7. The tangential direction at any interval of each group of balance holes 71 has an included angle with the horizontal direction.

[0038] As Figure 3 and Figure 4 shown, in this embodiment, the end of the annular clamping platform 7 close to the chuck 5 has a lapping portion 72. The lapping portion 72 includes an inclined annular abutting surface 721 and a horizontally arranged annular transition surface 722 directly connected to the annular abutting surface 721; it should be noted that in this embodiment, one end of the balance hole 71 extends to the gap between the annular clamping platform 7 and the valve stem 4, and the other end extends to the annular transition surface 722 of the lapping portion 72; it should also be noted that when the balance hole 71 is in a communication state with the communication hole 81 at the bottom of the valve housing 8, the annular abutting surface 721 is in close contact with the inclined plane of the outer peripheral wall of the first chuck portion 51 of the chuck 5.

[0039] As Figure 3 and Figure 4As shown, in this embodiment, the chuck 5 is located between the valve housing 8 and the annular clamping platform 7, and there is a margin for movement of the chuck 5 along the axis direction of the valve stem 4. When the second clamping portion 52 at the bottom of the chuck 5 disengages from the inner bottom wall of the valve housing 8, the inner cavity of the guide sleeve 3, the balance hole 71, and the communication hole 81 remain in communication. The inclined plane on the outer peripheral wall of the first clamping portion 51 of the chuck 5 is in close contact with the annular contact surface 721 of the annular clamping platform 7. When the second clamping portion 52 at the bottom of the chuck 5 is in contact and sealed with the inner bottom wall of the valve housing 8, the balance hole 71 and the communication hole 81 are in a non-connected state, and the inclined plane on the outer peripheral wall of the first clamping portion 51 of the chuck 5 disengages from the annular contact surface 721 of the annular clamping platform 7.

[0040] As Figure 3 and Figure 4 shown, in this embodiment, a lapping groove 1131 is provided along the circumferential direction of the valve seat 113 on the inner peripheral wall of the end of the valve seat 113 close to the guide sleeve 3. When the intake passage 111 and the exhaust passage 112 are in a non-connected state, the outer peripheral wall of the valve housing 8 is in contact and sealed with the lapping groove 1131. When the intake passage 111 and the exhaust passage 112 are in a connected state, the outer peripheral wall of the valve housing 8 and the lapping groove 1131 are separated from each other.

[0041] In summary, for the regulating valve according to the embodiment of the present invention, during use, when it is necessary to close the regulating valve, the piston rod of the oil motor drives the valve stem 4 to rotate within the valve cover 2 and the guide sleeve 3, causing the valve stem 4 to move in the direction close to the valve seat 113. At the same time, the valve stem 4 drives the valve sleeve 6 and the valve housing 8 to move synchronously in the direction close to the valve seat 113 through the lapping fit between the chuck 5 and the annular clamping platform 7. During the whole process, the chuck 5 is always in contact with the bottom end of the annular clamping platform 7. That is, in this state, the inner cavity of the guide sleeve 3, the balance hole 71, the communication hole 81, the intake passage 111, and the exhaust passage 112 are in a connected state until the valve housing 8 is in contact and sealed with the valve seat 113. At this time, the upper part of the chuck 5 disengages from the annular clamping platform 7, the lower part of the chuck 5 is in contact and sealed with the inner bottom wall of the valve housing 8, and the intake passage 111 and the exhaust passage 112 are in a non-connected state, and the regulating valve is closed;

[0042] When it is necessary to open the regulating valve, the piston rod of the oil motor drives the valve stem 4 to rotate within the valve cover 2 and the guide sleeve 3, causing the valve stem 4 to move in the direction away from the valve seat 113. At the same time, the valve stem 4 drives the valve sleeve 6 and the valve housing 8 to move synchronously in the direction away from the valve seat 113 through the lapping fit between the chuck 5 and the annular clamping platform 7. During this process, the bottom of the chuck 5 disengages from the valve housing 8 until the upper part of the chuck 5 is in contact with the bottom end of the annular clamping platform 7. When the valve housing 8 disengages from the valve seat 113, the intake passage 111 and the exhaust passage 112 are connected, and the regulating valve is opened;

[0043] When the regulating valve is in the closed state, since the lower part of the chuck 5 abuts against and seals the inner bottom wall of the valve housing 8, in this state, the intake passage 111 and the exhaust passage 112 are in a non-connected state (closed state), that is, the inner cavity of the guide sleeve 3, the balance hole 71 and the communication hole 81 are in a non-connected state (closed state). Therefore, there is basically no possibility of high-temperature and high-pressure steam leaking into the cylinder, making the regulating valve more tightly sealed in the closed state.

[0044] In an unimplemented embodiment, a steam turbine is provided, which includes the steam turbine regulating valve described in any of the above embodiments.

[0045] In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "vertical" and "horizontal" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0046] In addition, terms such as "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. In the description of the present invention, the meaning of "a plurality" is more than two, unless otherwise specifically defined.

[0047] In the present application, unless otherwise clearly specified and limited, terms such as "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0048] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A steam turbine regulating valve, comprising a valve body (1) with an open top and a valve cover (2) installed at the opening of the valve body (1). A valve chamber (11) is arranged in the valve body (1), and the valve chamber (11) includes an intake passage (111), an exhaust passage (112) that communicate with each other, and a valve seat (113) disposed in the middle of the valve chamber (11). A guide sleeve (3) coaxial with the valve seat (113) is also installed on the inner peripheral wall at the top opening of the valve body (1). Characterized in that: A valve rod (4) passes through between the valve body (1) and the valve cover (2). The upper part of the valve rod (4) is rotatably connected to both the valve cover (2) and the guide sleeve (3). The lower part of the valve rod (4) extends into the inner cavity of the guide sleeve (3), and a chuck (5) is installed on the lower end face thereof. A valve sleeve (6) is also sleeved on the lower part of the valve rod (4). The outer peripheral wall of the valve sleeve (6) is in close contact with the inner peripheral wall of the guide sleeve (3), and there is a gap between the inner peripheral wall of the valve sleeve (6) and the outer peripheral wall of the valve rod (4). An annular clamping platform (7) that is lapped and matched with the chuck (5) is also arranged at the bottom end of the valve sleeve (6). Multiple groups of balance holes (71) are evenly distributed along the circumferential direction of the annular clamping platform (7). The tangential direction at any interval of each group of balance holes (71) has an included angle with the horizontal direction. A valve housing (8) with a communication hole (81) opened at the bottom is also sleeved outside the annular clamping platform (7). The chuck (5) is located between the valve housing (8) and the annular clamping platform (7), and there is a movement margin along the axial direction of the valve rod (4). When the bottom of the chuck (5) disengages from the valve housing (8), the inner cavity of the guide sleeve (3), the balance holes (71), and the communication hole (81) are kept in communication with each other.

2. A steam turbine regulating valve according to claim 1, Characterized in that: The chuck (5) includes a first clamping part (51) directly connected to the valve rod (4) and a second clamping part (52) connected to the first clamping part (51). Among them, the end of the first clamping part (51) far from the valve rod (4) is flared, and the outer peripheral wall of the first clamping part (51) is a smooth inclined plane; the end of the second clamping part (52) far from the first clamping part (51) is constricted, and the outer peripheral wall of the second clamping part (52) is a smooth arc surface; when the balance holes (71) and the communication hole (81) at the bottom of the valve housing (8) are not in a communicating state, the outer peripheral wall of the second clamping part (52) is in sealing contact with the inner bottom wall of the valve housing (8).

3. A steam turbine regulating valve according to claim 2, Characterized in that: The end of the annular clamping platform (7) close to the chuck (5) has a lapping part (72) lapped and matched with the chuck (5). The lapping part (72) includes an inclined annular contact surface (721) and a horizontally arranged annular transition surface (722) directly connected to the annular contact surface (721); when the balance holes (71) and the communication hole (81) at the bottom of the valve housing (8) are in a communicating state, the annular contact surface (721) is in close contact with the inclined plane of the outer peripheral wall of the first clamping part (51).

4. A steam turbine regulating valve according to claim 3, Characterized in that: A gap is left between the inner peripheral wall of the annular clamping table (7) and the outer peripheral wall of the valve stem (4), and one end of the balance hole (71) extends to the gap between the annular clamping table (7) and the valve stem (4), and the other end extends to the annular transition surface (722) of the overlapping portion (72).

5. A steam turbine regulating valve according to claim 1, characterized in that: A lapping groove (1131) is formed in the inner peripheral wall of the valve seat (113) near one end of the guide sleeve (3) along the circumferential direction of the valve seat (113). When the intake passage (111) and the exhaust passage (112) are in a non-connected state, the outer peripheral wall of the valve housing (8) abuts against and seals the lapping groove (1131).

6. A steam turbine regulating valve according to claim 2, characterized in that: The first clamping portion (51) and the second clamping portion (52) are of an integrally formed structure, and the connection between the first clamping portion (51) and the second clamping portion (52) has a smooth transition.

7. A steam turbine regulating valve according to claim 1, characterized in that: The connection mode between the valve housing (8) and the annular clamping table (7) is bolt connection, threaded connection or clamping connection.

8. A steam turbine regulating valve according to claim 1, characterized in that: The annular clamping table (7) and the valve sleeve (6) are of an integrally formed structure.

9. A steam turbine, characterized in that, It includes the steam turbine regulating valve according to any one of claims 1-8.

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