A steam turbine independently controlled high pressure main steam regulating valve

Abstract

The present invention relates to a steam turbine independently controlled high-pressure main steam regulating valve, comprising a valve body, on which a first valve, a second valve and a third valve which are arranged transversely and parallel to each other are installed, and the three valves have the same structure; the valve body is provided with a steam inlet, and three guide holes for installing the valves are provided on the upper side of the valve body corresponding to the steam inlet, and three steam outlet holes which are coaxially opposite to the guide holes are provided on the lower side of the valve body corresponding to the steam inlet; each valve comprises a guide valve sleeve, a valve stem and a valve seat, the guide valve sleeve is installed in the guide hole, the valve stem is inserted in the central through hole of the guide valve sleeve, the valve tail of the valve stem extends upwardly out of the guide valve sleeve and is connected to the oil motor through a coupling, the valve head of the valve stem is mounted on the lower part of the guide valve sleeve and cooperates with the oil motor to enter and exit the guide valve sleeve, and the valve seat corresponds to the lower part of the valve head and is fixed at the steam outlet hole; the present invention provides a steam turbine independently controlled high-pressure main steam regulating valve, which realizes the function of coordinating steam flow through the design of combined steam valves which are independent of each other but can work together.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbine valve equipment, and in particular to an independently controlled high-pressure main steam regulating valve for a steam turbine. Background Art

[0002] Steam turbine is the main equipment of thermal power plant. The steam intake and exhaust of steam turbine are realized through the coordinated action of various valves. Among them, the high-pressure main steam regulating valve is the valve for regulating the main steam flow. It is generally set at the rear end of the main steam valve. There are 4 valves, which are symmetrically installed on both sides of the steam turbine to regulate the speed of steam entering the high-pressure cylinder to do work. Each high-pressure main steam regulating valve is equipped with its own oil motor, valve body, valve stem and valve seat. The existing conventional high-pressure main steam regulating valve has the following problems during operation:

[0003] 1. The valve seat of the high-pressure main steam regulating valve is assembled to the valve body by interference fit and fixed by surfacing welding. It is generally impossible to disassemble it. After long-term operation, the valve seat is damaged and can only be dismantled and replaced with a new one. The maintenance and installation cost is high and it is not easy to operate on site.

[0004] 2. The high-pressure main steam regulating valve uses a valve sleeve to achieve sliding and sealing between the valve stem and the valve body. The valve sleeve structure is a full-length structure, and the inner hole is sprayed with Stellite alloy or nitrided to slide with the valve stem. Due to the long valve stem, the spray layer falls off after long-term operation, the straightness is out of tolerance, the oxide scale is serious, and the jamming phenomenon is frequent.

[0005] 3. During the operation of the steam turbine unit, the valve stem and valve head are required not to rotate relative to the valve seat. Usually, in the design structure of the high-pressure main steam regulating valve, the valve stem and valve head are two parts, and an anti-rotation key and a positioning pin are set between the valve stem and the valve head to achieve anti-rotation and connection fixing functions respectively. However, the structural design is complex, and the connection position is severely oxidized after long-term operation, making disassembly and maintenance difficult. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a steam turbine independently controlled high-pressure main steam regulating valve, which realizes the function of coordinating steam flow through the design of combined steam valves that are independent of each other but can work together.

[0007] The technical solution adopted by the invention is: a steam turbine independently controlled high-pressure main steam regulating valve, comprising a valve body, on which a first valve, a second valve and a third valve are installed which are arranged transversely and parallel to each other, and the three valves have the same structure;

[0008] The valve body is provided with a steam inlet, and three guide holes for installing the valve are provided on the upper side of the valve body corresponding to the steam inlet, and three steam outlet holes coaxially opposite to the guide holes are provided on the lower side of the valve body corresponding to the steam inlet;

[0009] Each valve includes a guide valve sleeve, a valve stem and a valve seat. The guide valve sleeve is installed in the guide hole, the valve stem is inserted into the central through hole of the guide valve sleeve, the valve tail of the valve stem extends upward from the guide valve sleeve and is connected to the oil motor through a coupling, the valve head of the valve stem is mounted on the lower part of the guide valve sleeve and cooperates with the oil motor to enter and exit the guide valve sleeve, and the valve seat corresponds to the lower part of the valve head and is fixed at the steam outlet;

[0010] The guide valve sleeve comprises a positioning part located in the middle with a central through hole integrally passing through, a sliding part integrally connected above the positioning part and having a smaller diameter than the positioning part, and also comprises an action part integrally connected below the positioning part and having a smaller diameter than the positioning part; the outer side surface of the middle part of the positioning part is tightly clamped in the stepped hole preset in the guide hole, a circle of clamping ring groove is processed on the outer edge of the top of the positioning part, a sealing ring and an intermediate ring are installed on the lower groove surface of the clamping ring groove, a circular ring groove is provided in the guide hole outside the upper end surface of the intermediate ring, and a pressure ring of a split structure is installed in the ring groove, the outer side surface is clamped in the ring groove, and the inner side surface is clamped and connected to the upper groove surface of the clamping ring groove;

[0011] The upper part of the sliding part extends out of the guide hole, and an intermediate disk tightly fitted on the outer side of the sliding part is fixedly installed on the upper end surface of the guide hole, and a fastening nut threadedly connected to the outer side of the sliding part is pressed on the upper end surface of the intermediate disk; a sealing component is installed between the central through hole inside the sliding part and the valve stem, and the upper end of the sealing component is pressed and fixed by a locking nut which is hollow and mounted on the outside of the valve stem and whose outer side is threaded and screwed into a preset threaded hole at the center of the top of the sliding part;

[0012] The valve head of the valve stem is a cup-shaped structure with an opening at the lower part, the diameter of which is larger than the diameter of the middle section of the valve stem. The actuating part is provided with a stepped inner hole that is connected to the central through hole and matches the valve head. A piston ring is installed between the outer side surface of the valve head and the side wall of the stepped inner hole of the actuating part. A first balancing hole that passes through the upper and lower parts is provided at the bottom of the top cup of the valve head.

[0013] As a further limitation of the above technical solution, the diameters of the second valve and the third valve are equal and the largest, and the diameter of the first valve is the smallest.

[0014] As a further limitation of the above technical solution, the valve head is provided with a plurality of cyclone grooves on the outer side surface corresponding to the lower part of the piston ring, the outer side surface of the lower end of the valve head is processed with a circular chamfer, and the inner side surface of the central through hole provided on the valve seat corresponding to the contact with the circular chamfer of the valve head is processed into a circular surface.

[0015] As a further limitation of the above technical solution, the valve seat is interference fit in the preset step hole of the steam outlet through a cold installation process, and an anti-rotation pin that is interference fit with the valve body is installed on the side of the valve seat. A second balancing hole for balancing the internal and external air pressure of the anti-rotation pin body is opened along the axis of the anti-rotation pin. A pin removal thread is processed on the outer end of the second balancing hole, and a screw plug is installed on the valve body outside the anti-rotation pin.

[0016] As a further limitation of the above technical solution, turbulent peaks are arranged on both sides of the valve seat in the valve body.

[0017] As a further limitation of the above technical solution, the oil motor is connected to the valve body through a hollow oil motor valve column, the upper end of the oil motor valve column is fixedly connected to the oil motor through a flange with a stop structure and bolts, the lower end of the oil motor valve column is clamped on the middle disk on the upper end face of the valve body through a flange with a stop, a stud is passed through the flange hole of the lower end flange, the stud passes downward through the middle disk and is threadedly connected to the preset thread on the side wall of the guide hole of the valve body, and the upper end of the stud is tightened and fixed by a nut.

[0018] As a further limitation of the above technical solution, the coupling includes an intermediate shaft, a main body, a safety plate and a vertical bracket. The output shaft of the oil motor is connected to the upper part of the intermediate shaft by threads and an anti-loosening gasket is installed. The lower part of the intermediate shaft is installed in a threaded hole pre-opened in the center of the upper part of the main body by threaded matching. The lower part of the main body is provided with a notch groove that passes through the threaded hole from top to bottom and is transparent from front to back. The top of the notch groove is clamped and fixed with a safety plate that is matched with a preset directional flat at the bottom of the intermediate shaft. The notch groove below the safety plate is provided with a ring groove with a square cross section. Two half nuts with four outer sides corresponding to the ring groove are installed in the ring groove. One side of the two half nuts is fixedly connected by screws, and the other side of the two half nuts is fixedly connected to the vertical bracket. The upper end of the valve stem extends into the lower part of the main body and is installed in the threaded through holes of the two half nuts by threads. The valve stem extends out of the lower part of the main body and is processed with a circle of square flat with a square cross section. The lower part of the vertical bracket is provided with forks on the left and right sides of the horizontally clamped square flat, and the ends of the forks are fixedly connected by screws.

[0019] As a further limitation of the above technical solution, the directional flat is a cuboid with a rectangular cross-section, and a positioning groove matching the directional flat is opened in the center of the safety plate. The groove edge of the positioning groove fits tightly with the short side of the directional flat and has a gap with the long side of the directional flat.

[0020] As a further limitation of the above technical solution, the middle upper section of the guide valve sleeve positioning part is tightly matched with the stepped hole of the guide hole, the middle lower section of the positioning part and the lower part of the positioning part are arranged as stepped shafts with gradually smaller diameters, and a gap is reserved between the middle lower section of the positioning part and the stepped hole.

[0021] As a further limitation of the above technical solution, the sealing assembly includes a group of graphite sealing rings and carbon pressure ring bushings pressed on the upper and lower ends of the graphite sealing rings, the carbon pressure ring bushing at the lower end is clamped on a preset step of the center through hole, and a locking nut is pressed on the carbon pressure ring bushing at the upper end, and the outer end of the locking nut extending out of the sliding part is fixedly connected to an adjusting wrench for providing tightening force.

[0022] By adopting the above technology, the advantages of the present invention are:

[0023] The present invention proposes a novel integrated independently controlled high-pressure main steam regulating valve, which abandons the traditional dispersed arrangement of high-pressure main steam regulating valves, and is respectively assembled into valve A, valve B, and valve C by three independent sets of oil motors, valve stems, valve seats, valve sleeves and other components. Each valve can independently operate to adjust its own steam flow, and can also be combined into a joint steam valve to achieve the three valves to coordinate the steam flow together, and can achieve independent regulation and control of the steam flow for different load conditions, meet the operation requirements of the steam turbine under different working conditions, greatly save installation space, and reduce production costs.

[0024] The valve stem of the main steam regulating valve in the present invention has two functions. It can not only move back and forth in the regulating valve body to realize the stroke action, but the lower end of the valve stem can also be regarded as a valve head, which cooperates with the valve seat sealing surface to realize the opening and closing action of the valve. The structural design is simple and the disassembly and assembly are quick and easy to maintain.

[0025] The valve stem anti-rotation structure of the main steam regulating valve in the present invention is arranged outside the regulating valve body, and the oil motor output shaft and the intermediate shaft are fixedly connected through the coupling and the vertical bracket. The anti-rotation function of the intermediate shaft and the coupling is realized through the installation cooperation of the positioning groove and the directional flat. The anti-rotation function of the coupling, the intermediate shaft and the valve stem is realized through the cooperation and clamping of the fork of the square flat and the vertical bracket. Compared with the traditional structure in which the anti-rotation pin is arranged inside the valve body, the valve stem in the present invention solves the problem of jamming caused by high temperature after long-term use, and the anti-rotation structure is arranged outside, which is easy to disassemble and repair, thereby improving the efficiency of on-site maintenance.

[0026] In the present invention, the valve seat and the valve body are arranged as a detachable structure, the valve seat is installed in the exhaust hole of the valve body by interference fit, and an anti-rotation pin is arranged on one side to realize the dual functions of positioning and anti-rotation. During maintenance, the valve seat and the anti-rotation pin can be pulled out and replaced with a new valve seat or repaired offline. The problem that the traditional valve seat cannot be disassembled after surfacing welding is solved, and it has the advantages of convenient disassembly and assembly and high maintenance efficiency.

[0027] In the present invention, the turbulence peak is provided to prevent the steam from blowing the valve stem and the valve head, and to shear and divert the steam inside the valve body.

[0028] The carbon compression ring bushing and the graphite sealing ring arranged between the valve stem and the guide valve sleeve in the present invention have the characteristics of low hardness, high temperature resistance, corrosion resistance and wear resistance, effectively protect the contact surface with the valve stem and increase the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the connection between the high-pressure main steam regulating valve and the high-pressure cylinder of the present invention;

[0030] Figure 2 The high pressure main steam regulating valve of the present invention Figure 1AA section view;

[0031] Figure 3 for Figure 2 A magnified image of point A;

[0032] Figure 4 for Figure 2 A magnified view of point B;

[0033] Figure 5 The high pressure main steam regulating valve of the present invention Figure 2 DD cross-sectional view;

[0034] Figure 6 The high pressure main steam regulating valve of the present invention Figure 2 EE cross-sectional view.

[0035] In the figure: 1-valve body; 101-steam inlet; 102-steam outlet; 103-flange hole; 104-sealing groove; 2-first valve; 3-second valve; 4-third valve;

[0036] 5-guide valve sleeve; 501-positioning part; 502-sliding part; 503-acting part; 504-sealing ring; 505-middle ring; 506-pressure ring; 507-steam outlet; 508-middle plate; 509-exhaust hole; 510-graphite sealing ring; 511-carbon pressure ring bushing; 512-locking nut; 513-adjusting wrench; 514-fastening nut;

[0037] 6-valve stem; 601-piston ring; 602-cyclone groove; 603-first balance hole;

[0038] 7-valve seat; 701-anti-rotation pin; 702-second balance hole; 703-screw plug; 704-turbine peak;

[0039] 801-intermediate shaft; 802-main body; 804-vertical bracket; 805-anti-loosening gasket; 806-directional flat; 807-safety plate; 808-half nut; 809-square flat; 810-second heat insulation board;

[0040] 9- oil motor; 901- oil motor valve column; 902- gasket; 903- stud; 904- support sleeve; 905- support plate; 906- first heat insulation plate; 10- high pressure cylinder. DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0042] Example 1

[0043] like Figure 1-6As shown, a steam turbine independently controlled high-pressure main steam regulating valve comprises a valve body 1, a cavity is provided inside the valve body 1, a steam inlet 101 is provided on the left end face of the valve body 1, three guide holes are provided in the same row at intervals on the upper side face of the valve body 1, a first valve 2, a second valve 3, and a third valve 4 are respectively installed in the three guide holes, and three steam outlet holes 102 are provided on the lower side face of the valve body 1, and the three steam outlet holes 102 are coaxially opposite to the three guide holes.

[0044] The end face of the steam inlet 101 of the valve body 1 is provided with a flange integrally connected to the valve body 1, and the main steam valve is connected by bolts installed in the flange hole. The flange is provided with a sealing groove 104, and a toothed sealing gasket is installed in the sealing groove 104 to achieve the end face sealing of the two valves. The main steam regulating valve regulates and controls the steam input by the main steam valve through the steam inlet 101, and transmits it to the high-pressure cylinder, which then performs subsequent work.

[0045] The first valve 2, the second valve 3 and the third valve 4 are installed in the three guide holes on the valve body 1 from left to right. The three valves have the same internal structure, including a guide valve sleeve 5, a valve stem 6 and a valve seat 7. The guide valve sleeve 5 is installed in the guide hole, and the middle section of the valve stem 6 is inserted into the central through hole of the guide valve sleeve 5; the valve tail of the valve stem 6 extends upward from the guide valve sleeve 5 and is connected to the oil motor 9 through a coupling; the valve head of the valve stem 6 is mounted on the lower part of the guide valve sleeve 5 and cooperates with the oil motor 9 to enter and exit the guide valve sleeve 5; the valve seat 7 corresponds to the lower part of the valve head and is fixed at the steam outlet 102.

[0046] The connection between the valve stem 6 and the valve body 1 is as follows Figure 3-Figure 4 As shown, the guide valve sleeve 5 includes a positioning portion 501 located in the middle, a sliding portion 502 integrally connected above the positioning portion 501, and an action portion 503 integrally connected below the positioning portion 501. The diameter of the sliding portion 502 is smaller than the diameter of the action portion 503, and the diameter of the action portion 503 is smaller than the diameter of the positioning portion 501.

[0047] The positioning portion 501 is provided with an integral central through hole, the middle upper section of the positioning portion 501 is tightly matched with the preset stepped hole of the guide hole, the middle lower section of the positioning portion 501 and the lower part of the positioning portion 501 are stepped shafts with gradually smaller diameters, and a gap is reserved between the middle lower section of the positioning portion 501 and the stepped hole.

[0048] A circle of clamping ring groove is processed on the outer edge of the top of the positioning part 501. The lower groove surface of the clamping ring groove is installed with a sealing ring 504 and an intermediate ring 505 from bottom to top. The sealing ring 504 is pressed and processed by high temperature resistant and wear resistant graphite material. A circular ring groove is opened on the guide hole outside the upper end surface of the intermediate ring 505. A pressure ring 506 is installed in the ring groove. The pressure ring 506 is set as a split four-half structure. The outer side of the pressure ring 506 is clamped in the ring groove, and the inner side of the pressure ring 506 is clamped with the upper groove surface of the clamping ring groove to achieve the axial positioning of the guide valve sleeve 5. The ring groove surface matched with the pressure ring 506 is opened with a steam outlet 507 connected to the outside. The right side of the steam outlet 507 is connected to the exhaust steel pipe through a thread to guide the steam to the steam expansion tank.

[0049] The upper part of the sliding part 502 extends out of the guide hole, and the middle plate 508 is fixedly installed on the upper end surface of the guide hole. The center of the middle plate 508 is tightly fitted on the outer side surface of the sliding part 502. The upper end surface of the middle plate 508 is press-fitted with a fastening nut 514 threadedly connected to the outer side surface of the sliding part 502. The center of the upper end surface of the middle plate 508 is provided with a stop groove for matching the installation nut, so as to realize the axial positioning of the guide valve sleeve 5. The middle plate 508 is provided with an exhaust hole 509 connecting the inside and outside of the valve body 1. The exhaust hole 509 is threadedly connected to the exhaust steel pipe to timely guide the steam entering the sliding part 502 out of the valve body 1.

[0050] The sliding part 502 is provided with a central through hole which is integrally connected with the positioning part 501. A sealing assembly is installed between the central through hole and the valve stem 6. The sealing assembly includes a group of graphite sealing rings 510 and carbon pressure ring bushings 511 which are pressed on the upper and lower ends of the graphite sealing rings 510. The graphite sealing rings 510 are installed in a series, which have the characteristics of low hardness, high temperature resistance, corrosion resistance and wear resistance, effectively protecting the contact surface with the valve stem 6 and improving the service life. The carbon pressure ring bushing 511 is composed of a bushing matrix and a graphite ring installed in the matrix. The carbon pressure ring bushing 511 at the lower end is clamped on the preset step of the central through hole inside the sliding part 502; the carbon pressure ring bushing 511 at the upper end is clamped and fixed by a locking nut 512. The locking nut 512 is hollow inside and is mounted outside the valve stem 6. The outer side surface of the locking nut 512 is screwed and embedded in the threaded hole on the upper part of the sliding part 502 which is connected with the central through hole. The upper end of the locking nut 512 extends out of the top of the sliding portion 502 , and the extended portion is fixedly connected to the adjusting wrench 513 for providing a tightening force, applying a suitable torque and pre-tightening force to the sealing assembly and ensuring the adjustment of the installation clearance with the valve stem 6 .

[0051] The valve head of the valve stem 6 is a cup-shaped structure with an increased diameter and an opening at the bottom. The lower end surface of the action part 503 extends between the axis of the steam inlet and the upper end surface of the valve seat. The action part 503 is provided with a stepped inner hole connected to the central through hole inside the sliding part 502, and the stepped inner hole cooperates with the valve head.

[0052] A piston ring 601 is installed between the outer side of the valve head and the side wall of the stepped inner hole of the action part 503 to prevent steam leakage. A plurality of cyclone grooves 602 are provided on the outer side of the valve head corresponding to the lower part of the piston ring 601. The number of cyclone grooves 602 is 4-6 and they are always fitted in the stepped inner hole of the action part 503, thereby generating steam resistance for the steam entering the gap, changing the airflow direction and forming a cyclone, thereby reducing and eliminating the penetration of steam into the piston ring 601.

[0053] In order to correspond to the three independent steam outlet grooves of the subsequent guide controller and the amount of work done by the counterclockwise blade, the diameter of the valve seat 7 of the first valve 2 is the smallest, and the diameters of the valve seats 7 of the second valve 3 and the third valve 4 are equal and the largest. That is, the inner diameter of the valve seat 7 of the first valve 2 is the smallest, and the inner diameters of the valve seats 7 of the second valve 3 and the third valve 4 are equal and the largest. Different diameters indicate different maximum steam intake. In order to realize the direction and speed of rotor rotation, the first valve 2 is located at the steam inlet 101. According to the difference in diameters set for the first valve 2, the second valve 3, and the third valve 4, and the separate control of the opening and closing strokes, the function of independently adjusting the flow of steam is realized.

[0054] A first balancing hole 603 is provided at the bottom of the top cup of the valve head, which is symmetrically distributed along the axis of the valve stem 6. The first balancing hole 603 can be a straight hole parallel to the axis of the valve stem 6, or an inclined hole at an angle to the axis of the valve stem 6. When the valve stem 6 moves upward, the steam enters the valve seat 7 in one way and flows downward to the guide controller, and enters the upper part of the valve head through the first balancing hole 603 in the other way, and is blocked by the sealing function of the sealing component and then flows downward into the valve seat 7, thus achieving air pressure balance and follow-up performance between the upper part and the lower part of the valve head under working conditions.

[0055] The outer side surface of the lower end of the valve head is processed with an arc chamfer, and the valve seat 7 is provided with a central through hole. The inner side surface of the central through hole of the valve seat 7 corresponding to the contact with the arc chamfer of the valve head is processed into an arc surface. The valve head of the valve stem 6 slides downward in the stepped inner hole of the action part 503 and contacts and cooperates with the arc surface of the valve seat 7 to realize the opening and closing of the valve.

[0056] The cross-sectional view of the valve seat 7 is as follows Figure 5As shown, the valve seat 7 is interference-fitted in the preset step hole of the steam outlet 102 through a cold assembly process, and the side of the valve seat 7 is grooved and an anti-rotation pin 701 that is interference-fitted with the valve body 1 is installed, thereby realizing the anti-rotation function and positioning function of the valve seat 7. The anti-rotation pin 701 has a second balancing hole 702 for balancing the air pressure inside and outside the anti-rotation pin 701 body along the anti-rotation pin axis, so as to ensure that the air pressure inside and outside the anti-rotation pin 701 is balanced and smoothly installed during the interference assembly process. The outer end of the second balancing hole 702 is processed with a pin removal thread so that it can be pulled and disassembled by screwing in a tool, and a screw plug 703 for sealing is installed on the valve body 1 outside the anti-rotation pin 701. After the main steam regulating valve has been in operation for a long time, the valve seat 7 that is damaged during operation can be repaired or replaced by disassembling the anti-rotation pin 701 and the screw plug 703, thereby reducing the maintenance cost and time.

[0057] The spoiler peaks 704 are arranged inside the valve body 1 and on the left and right sides of the valve seat 7. The spoiler peaks 704 are designed in a peak shape, so as to prevent the steam from blowing the valve stem 6 and the valve head of the valve stem 6, and shear and divert the steam entering the valve body 1. The height of the spoiler peak 704 is higher than the height of the valve head of the valve stem 6 exposed outward at the action part 503 of the guide valve sleeve 5, and is flush with the axis of the valve body 1. The length of the spoiler peak 704 facing the side of the steam inlet 101 of the valve body 1 is 1 / 2 of the diameter of the valve head. The distance of the spoiler peak 704 at the position of the second valve 3 is twice the distance of the spoiler peak 704 at the position of the first valve 2 and the third valve 4, thereby realizing that the second valve 3 is the main regulating valve, and the first valve 2 and the third valve 4 are the auxiliary regulating valves. The steam flow outputted by each of the first valve 2, the second valve 3 and the third valve 4 is controlled by controlling the action of the oil motor 9 of the first valve 2, the second valve 3 and the third valve 4.

[0058] The cross-sectional view of the valve stem 6 and the coupling is as follows: Figure 3 , Figure 6 As shown, the oil motor 9 is connected to the valve body 1 through a hollow oil motor valve column 901, the upper end of the oil motor valve column 901 is fixedly connected to the oil motor 9 through a flange with a stopper structure and bolts, and the lower end of the oil motor valve column 901 is clamped on the middle disk 508 on the upper end surface of the valve body 1 through a flange with a stopper, and gaskets 902 are installed on both sides of the middle disk 508. The lower end surface of the middle disk 508 is provided with a protruding stopper that matches the valve body 1, and the upper end surface of the middle disk 508 is provided with a protruding stopper that matches the oil motor valve column 901.

[0059] The stud 903 passes through the flange hole at the lower end of the oil motor valve column 901, and passes downward through the intermediate disk 508 and is threadedly connected to the preset thread on the side wall of the guide hole of the valve body 1. The upper end of the stud 903 passes through the support sleeve 904 and is tightened and fixed by a nut. The support sleeve 904 facilitates the disassembly and assembly of the stud 903.

[0060] A support plate 905 is fixed to the valve body 1 or the oil motor valve column 901 or the intermediate disk 508 by screws. The cross-section of the support plate 905 is an inverted L-shape. The vertical section of the support plate 905 is fixed to the valve body 1 or the oil motor valve column 901 or the intermediate disk 508. The horizontal section of the support plate 905 is fixedly connected to the first heat insulation plate 906 arranged around the lower part of the oil motor valve column 901, so as to prevent the heat influence on the oil motor valve column 901 and the oil motor 9 when the valve body 1 as a whole is heated.

[0061] The coupling includes an intermediate shaft 801 , a main body 802 , a safety plate 807 and a vertical bracket 804 .

[0062] The upper part of the intermediate shaft 801 is a column with a regular hexagonal cross-section. The upper part of the intermediate shaft 801 is connected to the output shaft of the oil motor 9 through a central threaded blind hole. An anti-loosening gasket 805 is installed between the output shaft of the oil motor 9 and the intermediate shaft 801. The anti-loosening gasket 805 is provided with two foldable long sides, and the two long sides are respectively attached to the outer side surface of the intermediate shaft 801 and the outer side surface of the output shaft of the oil motor 9, so as to realize the anti-loosening function of the output shaft of the oil motor 9 and the intermediate shaft 801. The lower part of the intermediate shaft 801 is installed in the threaded hole pre-opened in the center of the upper part of the main body 802 through threaded matching. The threaded end surface at the bottom of the intermediate shaft 801 is provided with a directional flat 806. The directional flat 806 is a cuboid with a rectangular cross section.

[0063] A notch groove is provided at the bottom of the main body 802, which passes through the threaded hole from top to bottom and is transparent on the front and back sides. A safety plate 807 matched with the directional flat is fixed to the top of the notch groove by screws. A positioning groove matching the directional flat 806 is provided in the center of the safety plate 807. The groove edge of the positioning groove fits tightly with the short side of the directional flat 806 and has a gap with the long side of the directional flat 806, thereby realizing the anti-rotation function of the intermediate shaft 801 and the main body 802.

[0064] The notch groove below the safety plate 807 is provided with a ring groove with a square cross section, and two half nuts 808 are installed in the ring groove, and the two half nuts 808 have four outer sides corresponding to the ring groove. One side of the two half nuts 808 is fixedly connected by screws to achieve the tightening and positioning of the two half nuts 808, and the other side of the two half nuts 808 is fixedly connected to a vertical bracket 804 by screws. The vertical bracket is L-shaped, including a vertical plate and two forks placed at the bottom of the vertical plate. The vertical plate is connected to the other side of the two half nuts 808, and the forks are horizontal plates, and the forks are arranged toward the valve stem 6.

[0065] The upper end of the valve stem 6 extends into the lower part of the main body 802 and is installed in the threaded through holes of the two half nuts 808 through threads. The valve stem 6 extends out from the bottom of the main body 802 and is processed with a circle of square flat 809 with a square cross-section. The fork is clamped in the square flat 809, and the end of the fork is fixedly connected to the square flat 809 by screws. The intermediate shaft 801 and the valve stem 6 are fixed and connected together through the main body 802, and it also has an anti-rotation positioning function.

[0066] A second heat insulation plate 810 with a two-half structure is fixedly installed on the top of the main body 802. The second heat insulation plate 810 has a center hole. The center hole of the second heat insulation plate 810 passes through the threaded root of the intermediate shaft 801 and is fixed to the main body 802 by screws, thereby blocking and dispersing the steam heat conducted by the valve stem 6, ensuring the normal operating temperature of the oil motor and ensuring the normal and stable operation of the valve under high temperature conditions.

[0067] The steam turbine independently controlled high-pressure main steam regulating valve described in the present invention has a working process in which steam enters the valve body 1 from the steam inlet 101, and then is divided through the turbulence peak 704 and flows around the valve seat 7. The oil motor 9 drives the valve stem 6 to slide up and down in the central through hole of the guide valve sleeve 5. When the valve head of the valve stem 6 contacts the valve seat 7, the valve is closed. When the valve head moves upward and leaves the valve seat 7, the valve opens, and steam comes out from the steam outlet 102. By adjusting the distance between the valve head and the valve seat 7, the flow rate of steam is adjusted. The first valve 2, the second valve 3, and the third valve 4 can not only control the steam flow rate outputted by each of them, but also coordinate the steam flow rate together to meet the operation requirements of the steam turbine under different working conditions.

[0068] The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technical solution obtained by any technician familiar with the field within the technical scope disclosed by the present invention by equivalent replacement or change based on the technical concept of the present invention should be included in the protection scope of the present invention.

Claims

1. A steam turbine independently controlled high-pressure main steam regulating valve, characterized in that: The valve body (1) comprises a first valve (2), a second valve (3) and a third valve (4) which are arranged in parallel with each other in a transverse direction and are installed on the valve body (1), and the three valves have the same structure; The valve body (1) is provided with a steam inlet (101), and three guide holes for installing the valve are provided on the upper side of the valve body (1) corresponding to the steam inlet (101), and three steam outlet holes (102) coaxially opposite to the guide holes are provided on the lower side of the valve body (1) corresponding to the steam inlet (101); Each valve comprises a guide valve sleeve (5), a valve stem (6) and a valve seat (7). The guide valve sleeve (5) is installed in the guide hole. The valve stem (6) is inserted into the central through hole of the guide valve sleeve (5). The valve tail of the valve stem (6) extends upward from the guide valve sleeve (5) and is connected to the oil motor (9) through a coupling. The valve head of the valve stem (6) is mounted on the lower part of the guide valve sleeve (5) and cooperates with the oil motor (9) to enter and exit the guide valve sleeve (5). The valve seat (7) corresponds to the lower part of the valve head and is fixed at the steam outlet hole (102). The guide valve sleeve (5) comprises a positioning portion (501) in the middle with a central through hole integrally passing therethrough, and a sliding portion (502) integrally connected to the upper part of the positioning portion (501) and having a smaller diameter than the positioning portion (501), and also comprises an actuating portion (503) integrally connected to the lower part of the positioning portion (501) and having a smaller diameter than the positioning portion (501); the outer side surface of the middle part of the positioning portion (501) is tightly clamped in a stepped hole preset in the guide hole, a circle of clamping ring groove is processed on the outer edge of the top of the positioning portion (501), a sealing ring (504) and an intermediate ring (505) are installed on the lower groove surface of the clamping ring groove, a circular ring groove is provided on the outer side of the upper end surface of the intermediate ring (505), and a pressure ring (506) of a split structure is installed in the ring groove, the outer side surface is clamped in the ring groove, and the inner side surface is clamped and connected to the upper groove surface of the clamping ring groove; The upper part of the sliding part (502) extends out of the guide hole, and an intermediate disk (508) is fixedly installed on the upper end surface of the guide hole, and the intermediate disk (508) is tightly fitted on the outer side surface of the sliding part (502). The upper end surface of the intermediate disk (508) is pressed with a fastening nut (514) threadedly connected to the outer side surface of the sliding part (502); a sealing component is installed between the central through hole inside the sliding part (502) and the valve stem (6), and the upper end of the sealing component is pressed and fixed by a locking nut (512) which is hollow and mounted on the outside of the valve stem (6) and is screwed on the outer side surface to be embedded in the central preset threaded hole at the top of the sliding part (502); The valve head of the valve stem (6) is a cup-shaped structure with an opening at the lower part, the diameter of which is larger than the diameter of the middle section of the valve stem (6); the actuating portion (503) is provided with a stepped inner hole communicating with the central through hole and matching with the valve head; a piston ring (601) is installed between the outer side surface of the valve head and the side wall of the stepped inner hole of the actuating portion (503); and a first balancing hole (603) is provided at the bottom of the top cup of the valve head, which is through-and-through from top to bottom; The diameters of the second valve (3) and the third valve (4) are equal and the largest, and the diameter of the first valve (2) is the smallest; The outer side surface of the valve head corresponding to the lower part of the piston ring (601) is provided with a plurality of cyclone grooves (602), the outer side surface of the lower end of the valve head is processed with a circular chamfer, and the inner side surface of the central through hole provided in the valve seat (7) corresponding to the contact with the circular chamfer of the valve head is processed into a circular arc surface.

2. The turbine independently controlled high-pressure main steam regulating valve according to claim 1, characterized in that: The valve seat (7) is interference-fitted in a preset stepped hole of the steam outlet (102) through a cold-installation process; an anti-rotation pin (701) interference-fitted with the valve body (1) is installed on the side of the valve seat (7); a second balancing hole (702) for balancing the air pressure inside and outside the anti-rotation pin (701) body is provided along the anti-rotation pin axis; a pin removal thread is processed on the outer end of the second balancing hole (702); and a screw plug (703) is installed on the valve body (1) outside the anti-rotation pin (701).

3. The turbine independently controlled high-pressure main steam regulating valve according to claim 1, characterized in that: Flow disturbance peaks (704) are arranged on both sides of the valve seat (7) in the valve body (1).

4. The independently controlled high-pressure main steam regulating valve for a steam turbine according to claim 1, characterized in that: The oil motor (9) is connected to the valve body (1) via a hollow oil motor valve column (901); the upper end of the oil motor valve column (901) is fixedly connected to the oil motor (9) via a flange with a stop structure and bolts; the lower end of the oil motor valve column (901) is clamped on the middle plate (508) on the upper end surface of the valve body (1) via a flange with a stop; a stud (903) is inserted into the flange hole of the lower end flange; the stud (903) passes downward through the middle plate (508) and is threadedly connected to a preset thread on the side wall of the guide hole of the valve body (1); the upper end of the stud (903) is tightened and fixed by a nut.

5. The independently controlled high-pressure main steam regulating valve for a steam turbine according to claim 1, characterized in that: The coupling comprises an intermediate shaft (801), a main body (802), a safety plate (807) and a vertical bracket (804); the output shaft of the oil motor (9) is connected to the upper part of the intermediate shaft (801) by threads and a loose-proof gasket (805) is installed; the lower part of the intermediate shaft (801) is installed in a threaded hole pre-opened in the center of the upper part of the main body (802) by threaded matching; the lower part of the main body (802) is provided with a notch groove which passes through the threaded hole from top to bottom and is transparent from front to back; the top of the notch groove is clamped and fixed with a safety plate (807) which is matched with a directional flat (806) pre-set at the bottom of the intermediate shaft (801); the notch groove below the safety plate (807) is provided with a ring with a square cross section The annular groove is provided with two half nuts (808) which are split to the left and right and have four outer sides corresponding to the annular groove. One side of the two half nuts (808) is fixedly connected by screws, and the other side of the two half nuts (808) is fixedly connected to the vertical bracket (804). The upper end of the valve stem (6) extends into the lower part of the main body (802) and is installed in the threaded through holes of the two half nuts (808) by threads. The valve stem (6) extends out from the lower part of the main body (802) and is processed with a circle of square flat (809) with a square cross section. The lower part of the vertical bracket (804) is provided with forks on the left and right sides of the horizontally clamped square flat (809), and the ends of the forks are fixedly connected by screws.

6. The turbine independently controlled high-pressure main steam regulating valve according to claim 5, characterized in that: The directional flat (806) is a cuboid with a rectangular cross section. A positioning groove matching the directional flat (806) is provided at the center of the safety plate (807). The groove edge of the positioning groove is tightly matched with the short side of the directional flat (806) and has a gap with the long side of the directional flat (806).

7. The turbine independently controlled high-pressure main steam regulating valve according to claim 1, characterized in that: The middle upper section of the positioning portion (501) of the guide valve sleeve (5) is tightly matched with the stepped hole of the guide hole, the middle lower section of the positioning portion (501) and the lower part of the positioning portion (501) are arranged as stepped shafts with gradually decreasing diameters, and a gap is reserved between the middle lower section of the positioning portion (501) and the stepped hole.

8. The turbine independently controlled high-pressure main steam regulating valve according to claim 1, characterized in that: The sealing assembly comprises a group of graphite sealing rings (510) and carbon pressure ring bushings (511) pressed onto the upper and lower ends of the graphite sealing rings (510); the carbon pressure ring bushing (511) at the lower end is clamped onto a preset step of a central through hole; a locking nut (512) is pressed onto the carbon pressure ring bushing (511) at the upper end; the outer end of the locking nut (512) extending out of the sliding portion (502) is fixedly connected to an adjusting wrench (513) for providing a tightening force.

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