阅读说明：本技术 汽轮机进汽结构 (Steam inlet structure of steam turbine ) 是由 肖蕾 徐嗣华 何劲 胡志强 李月月 于 2020-06-28 设计创作，主要内容包括：本发明提供一种汽轮机进汽结构,包括若干个调节阀及与调节阀相连接的执行机构,调节阀包括具有进汽腔的阀体和安装在阀体中的阀芯,阀体上设有与进汽腔相连通的进汽孔,阀芯包括安装在进汽孔中且具有内孔的阀座、与阀座相配合的阀碟、及与阀碟相连接的阀杆,阀杆与执行机构相连接,至少一个调节阀的阀碟上设有锥形配合部,所述锥形配合部嵌在阀座的内孔中。由于至少一个调节阀的阀碟上设有锥形配合部,锥形配合部嵌在阀座的内孔中,这样,当阀碟向远离阀座移动相同较小的距离时,部分锥形配合部还位于内孔中,使得内孔及进汽孔未完全打开,通过内孔及进汽孔流过的蒸汽流量较小,提高了该调节阀及本进汽结构对蒸汽流量的调节灵敏度。(The invention provides a steam turbine steam inlet structure, which comprises a plurality of regulating valves and an actuating mechanism connected with the regulating valves, wherein each regulating valve comprises a valve body with a steam inlet cavity and a valve core arranged in the valve body, the valve body is provided with a steam inlet communicated with the steam inlet cavity, the valve core comprises a valve seat arranged in the steam inlet and provided with an inner hole, a valve disc matched with the valve seat and a valve rod connected with the valve disc, the valve rod is connected with the actuating mechanism, the valve disc of at least one regulating valve is provided with a conical matching part, and the conical matching part is embedded in the inner hole of the valve seat. Because be equipped with toper cooperation portion on the valve disc of at least one governing valve, toper cooperation portion inlays in the hole of disk seat, like this, when the valve disc when keeping away from the same less distance of disk seat removal, partial toper cooperation portion still is located the hole for hole and steam inlet are not opened completely, and the steam flow that flows through hole and steam inlet is less, has improved this governing valve and this admission structure to steam flow's regulation sensitivity.)

1. The utility model provides a steam turbine admission structure, its characterized in that includes a plurality of governing valve (1) and actuating mechanism (2) that are connected with governing valve (1), governing valve (1) is including valve body (11) that have steam inlet chamber (111) and install case (12) in valve body (11), be equipped with steam inlet hole (112) that are linked together with steam inlet chamber (111) on valve body (11), case (12) are including installing disk seat (121) that just has the hole in steam inlet hole (112), valve disc (122) with disk seat (121) matched with and valve rod (123) that are connected with valve disc (122), valve rod (123) are connected with actuating mechanism (2), are equipped with toper cooperation portion on valve disc (122) of at least one governing valve (1), toper cooperation portion inlays in the hole of disk seat (121).

2. Steam turbine admission structure according to claim 1, characterized in that the valve disc (122) of at least one regulating valve (1) is provided with balancing holes communicating with the admission holes (112) and the admission chamber (111).

3. The steam turbine steam inlet structure according to claim 1, characterized in that the valve rod (123) is connected with the actuator (2) through a lever mechanism (3), the lever mechanism (3) comprises a supporting seat (31) and a lever (32) which are fixed relative to the valve body (11), one end of the lever (32) is hinged with the supporting seat (31), the other end of the lever (32) is hinged with the actuator (2), the valve rod (123) is connected with the lever (32), and the connection point of the valve rod (123) and the lever (32) is located between the hinge point of the supporting seat (31) and the lever (32) and the hinge point of the actuator (2) and the lever (32).

4. The steam turbine inlet structure according to claim 3, wherein one end of the lever (32) is hinged to the support base (31) through a roller (33).

5. The steam turbine inlet structure according to claim 1, wherein the valve body (11) is provided with a mounting hole, the valve body (11) is provided with a valve cover (13) with a through hole, and an extending end (131) of the valve cover (13) is inserted into the mounting hole and extends into the steam inlet cavity (111); the valve rod (123) penetrates through a through hole of the valve cover (13), a bushing (132) sleeved on the valve rod (123) is installed in the through hole of the valve cover (13), and a sleeve (133) is installed at an extending end (131) of the valve cover (13).

6. The steam turbine inlet structure according to claim 5, wherein the sleeve (133) is threadedly coupled to the extension (131).

7. The steam turbine inlet structure of claim 5, wherein the sleeve (133) is provided with an upper locating seal surface and the valve disc (122) is provided with a lower locating seal surface, the upper locating seal surface being adapted to mate with the lower locating seal surface.

8. The steam turbine inlet structure according to claim 5, wherein a guide bush (134) is installed on an inner wall of the sleeve (133), and the guide bush (134) is fitted to an outer portion of the valve disc (122).

9. The steam turbine inlet structure according to claim 1, further comprising a spring box (4) mounted on the valve body (11), and the spring box (4) is capable of applying a force to the valve stem (123) toward the inlet opening (112).

10. The steam turbine inlet structure according to claim 1, further comprising a main steam valve (5) communicated with the valve body (11), and the main steam valve (5) is fixedly connected with the valve body (11) by welding or bolts.

11. The steam turbine inlet structure according to claim 1, wherein the taper angle of the tapered fitting portion is 60 to 80 degrees.

12. The steam turbine inlet structure according to claim 1, wherein the head of the valve disc (122) is a spherical portion having a flat surface or a concave surface.

13. The steam turbine inlet structure of claim 1, wherein the valve disc (122) and the valve stem (123) are of unitary construction.

Technical Field

The invention relates to the technical field of steam turbines, in particular to a steam inlet structure of a steam turbine.

Background

The industrial steam turbine of low parameter, low power adopts the nozzle to distribute vapour usually, and admission governing valve is more in quantity, adopts the lifter plate formula structure at present more: the valve heads are mounted on a beam and are controlled by a common set of lift pins. The regulating valve has the advantages of simple structure, compact arrangement and higher economic performance. Along with the continuous improvement of market to unit performance requirement, industrial steam turbine presents the development trend of high parameterization, and the improvement of admission parameter leads to current poppet formula governing valve to have following problem:

1. a plurality of valve heads of the lifting plate valve are controlled by a pair of common levers and the servomotor, the pressure of the valve heads cannot be relieved, and along with the improvement of steam parameters, the lifting force and the energy consumption required by the opening of the valve are obviously increased, so that the selection of the servomotor is difficult.

2. The valve disc, the cross beam and the lifting rod of the lifting plate valve are all arranged in the main flow, so that great interference is generated on the flow, and unstable flow such as turbulent flow, vortex and the like is easy to occur. Meanwhile, certain gaps are reserved among matching surfaces among the valve disc, the cross beam and the lifting rod so as to prevent the valve from being jammed due to thermal deformation in the opening and closing process. The presence of these assembly gaps results in valves that are susceptible to vibration and noise under the excitation of unstable vapors. As the steam parameters increase, the flow instability increases and the vibration and noise levels increase significantly, directly affecting the safe operation of the valve.

3. Poppet valves typically share a flat valve head with multiple valve heads, which are bolted to the cylinder. Along with the improvement of steam inlet parameters, the stress level and the deformation of the connecting flange of the cylinder and the valve cover are large, so that the design is difficult, and the safety and the economy are difficult to take into consideration.

4. The regulating sensitivity of the lifting plate valve to the steam flow is low, and the use requirement of starting the steam turbine under high parameters cannot be met.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention provides a steam turbine inlet structure with higher sensitivity for steam flow adjustment.

In order to achieve the purpose, the invention provides a steam turbine steam inlet structure, which comprises a plurality of regulating valves and an actuating mechanism connected with the regulating valves, wherein each regulating valve comprises a valve body with a steam inlet cavity and a valve core arranged in the valve body, the valve body is provided with a steam inlet communicated with the steam inlet cavity, the valve core comprises a valve seat arranged in the steam inlet cavity and provided with an inner hole, a valve disc matched with the valve seat and a valve rod connected with the valve disc, the valve rod is connected with the actuating mechanism, the valve disc of at least one regulating valve is provided with a conical matching part, and the conical matching part is embedded in the inner hole of the valve seat.

Furthermore, a valve disc of at least one regulating valve is provided with a balance hole communicated with the steam inlet hole and the steam inlet cavity.

Further, the valve rod is connected with the actuating mechanism through a lever mechanism, the lever mechanism comprises a supporting seat and a lever which are relatively fixed with the valve body, one end of the lever is hinged with the supporting seat, the other end of the lever is hinged with the actuating mechanism, the valve rod is connected with the lever, and the connecting point of the valve rod and the lever is located between the hinge point of the supporting seat and the lever and the hinge point of the actuating mechanism and the lever.

Further, one end of the lever is hinged with the supporting seat through a roller.

Furthermore, a mounting hole is formed in the valve body, a valve cover with a through hole is mounted on the valve body, and the extending end of the valve cover is inserted into the mounting hole and extends into the steam inlet cavity; the valve rod is arranged in the through hole of the valve cover in a penetrating mode, a bushing sleeved on the valve rod is arranged in the through hole of the valve cover, and a sleeve is arranged at the extending end of the valve cover.

Further, the sleeve is threadedly connected to the extension end.

Furthermore, an upper positioning sealing surface is arranged on the sleeve, a lower positioning sealing surface is arranged on the valve disc, and the upper positioning sealing surface is used for being matched with the lower positioning sealing surface.

Further, install the direction bush on the telescopic inner wall, just the outside at the valve dish is established to the direction bush cover.

Further, the steam turbine steam inlet structure further comprises a spring box installed on the valve body, and the spring box can apply force towards the steam inlet hole to the valve rod.

Furthermore, the steam turbine steam inlet structure further comprises a main steam valve communicated with the valve body, and the main steam valve is fixedly connected with the valve body through welding or bolts.

Further, the taper angle of the taper fitting portion is 60 degrees to 80 degrees.

Further, the head of the valve disc is a spherical portion having a flat or concave surface.

Further, the valve disc and the valve rod are of an integrated structure.

As described above, the steam turbine steam inlet structure according to the present invention has the following advantageous effects:

when the valve disc needs to be opened and the steam inlet amount is increased, the actuating mechanism acts and drives the valve disc to move in the direction away from the valve seat through the valve rod, the valve disc is separated from contact fit with the valve seat, and steam in the steam inlet cavity flows into the turbine through a gap between the valve disc and the valve seat, an inner hole and a steam inlet hole; because be equipped with toper cooperation portion on the valve disc of at least one governing valve, toper cooperation portion inlays in the hole of disk seat, like this, when the valve disc when keeping away from the same less distance of disk seat removal, partial toper cooperation portion still is located the hole for hole and steam inlet are not opened completely, and the steam flow that flows through hole and steam inlet is less, has improved this governing valve and this admission structure to steam flow's regulation sensitivity, the start-up of specially adapted steam turbine under the high parameter.

Drawings

Fig. 1 is a left side view of an intake structure of a steam turbine according to the present invention.

FIG. 2 is a schematic view of the steam turbine inlet structure of the present invention.

Description of the element reference numerals

1 regulating valve 13 valve cover

101 first regulating valve 131 extension end

102 second regulator valve 132 liner

103 third regulator valve 133 sleeve

104 fourth regulator valve 134 guide bushing

11 valve body 2 actuating mechanism

111 steam inlet cavity 3 lever mechanism

112 steam inlet hole 31 support base

12 spool 32 lever

121 valve seat 33 roller

122 valve disc 4 spring box

123 valve rod 5 main steam valve

124 connecting rod

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

It should be understood that the structures, ratios, sizes, and the like shown in the drawings are only used for matching the disclosure of the present disclosure, and are not used for limiting the conditions of the present disclosure, so that the present disclosure is not limited to the technical essence, and any modifications of the structures, changes of the ratios, or adjustments of the sizes, can still fall within the scope of the present disclosure without affecting the function and the achievable purpose of the present disclosure. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for convenience of description only, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention unless otherwise specified.

As shown in fig. 1 and fig. 2, the present embodiment provides a steam turbine steam inlet structure, which includes a plurality of regulating valves 1 and an actuating mechanism 2 connected to the regulating valves 1, where the regulating valves 1 include a valve body 11 having a steam inlet cavity 111 and a valve core 12 installed in the valve body 11, the valve body 11 is provided with a steam inlet 112 communicated with the steam inlet cavity 111, the valve core 12 includes a valve seat 121 installed in the steam inlet 112 and having an inner hole, a valve disc 122 matched with the valve seat 121, and a valve rod 123 connected to the valve disc 122, the valve rod 123 is connected to the actuating mechanism 2, the valve disc 122 of at least one regulating valve 1 is provided with a conical matching portion, and the conical matching portion is embedded in the inner hole of the valve seat 121. When the valve disc 122 needs to be opened and the steam inlet amount is increased, the actuating mechanism 2 acts and drives the valve disc 122 to move in the direction away from the valve seat 121 through the valve rod 123, the valve disc 122 is separated from the contact fit with the valve seat 121, and steam in the steam inlet cavity 111 flows into the turbine through the gap between the valve disc 122 and the valve seat 121, the inner hole and the steam inlet hole 112; because the conical matching part is arranged on the valve disc 122 of the at least one regulating valve 1 and embedded in the inner hole of the valve seat 121, when the valve disc 122 moves away from the valve seat 121 for the same small distance, part of the conical matching part is also positioned in the inner hole, so that the inner hole and the steam inlet hole 112 are not completely opened, the steam flow flowing through the inner hole and the steam inlet hole 112 is small, the regulating sensitivity of the regulating valve 1 and the steam inlet structure to the steam flow is improved, and the steam turbine is particularly suitable for starting a steam turbine under high parameters.

As shown in fig. 2, in the present embodiment, a balance hole communicating with the steam inlet hole 112 and the steam inlet chamber 111 is provided on the valve disc 122 of at least one regulating valve 1. Because the valve disc 122 of at least one regulating valve 1 is provided with the balance hole communicated with the steam inlet hole 112 and the steam inlet cavity 111, the pressure difference between the steam inlet hole 112 and the steam inlet cavity 111 is smaller under the state that the valve disc 122 is matched with the valve seat 121, so that when the actuating mechanism 2 is required to drive the valve disc 122 to move away from the valve seat 121, the pressure difference resistance required to be overcome is smaller, the lifting force required when the valve is opened is smaller, and the energy consumption is saved.

As shown in fig. 1, the steam inlet structure of the steam turbine in this embodiment includes one or two main steam valves 5 and a plurality of regulating valves 1, the main steam valves 5 are communicated with the valve body 11, and the main steam valves 5 are fixedly connected with the valve body 11 by welding or bolts. In the present embodiment, all the control valves 1 share one valve body 11. The main steam valve 5 is positioned on one side or both sides of the valve body 11. Steam enters the steam inlet cavity 111 of the regulating valve 1 through the main steam valve 5, and when the valve disc 122 is opened, the steam in the steam inlet cavity 111 enters the turbine through the steam inlet hole 112.

As shown in fig. 2, the steam inlet structure of the steam turbine in this embodiment specifically includes 4 regulating valves 1, wherein conical matching portions are provided on valve discs 122 of two regulating valves 1, and the two regulating valves 1 are a first regulating valve 101 and a third regulating valve 103, respectively; in addition, the valve discs 122 of the two regulating valves 1 are provided with balance holes communicated with the steam inlet hole 112 and the steam inlet cavity 111, and the two regulating valves 1 are the second regulating valve 102 and the fourth regulating valve 104 respectively. In the present embodiment, there is one main steam valve 5.

As shown in fig. 1, in the present embodiment, the valve rod 123 is connected to the actuator 2 through the lever mechanism 3, the lever mechanism 3 includes a support seat 31 and a lever 32 fixed opposite to the valve body 11, one end of the lever 32 is hinged to the support seat 31, the other end of the lever 32 is hinged to the actuator 2, the valve rod 123 is connected to the lever 32, and a connection point of the valve rod 123 and the lever 32 is located between a hinge point of the support seat 31 and the lever 32 and a hinge point of the actuator 2 and the lever 32. When the valve disc 122 needs to be opened, the actuator 2 drives the other end of the lever 32 to rotate upward around the hinge point between the lever 32 and the support seat 31, and drives the valve rod 123 to move upward, the valve rod 123 drives the valve disc 122 to move upward, i.e., to move in a direction away from the valve seat 121, the valve disc 122 is separated from the matching relationship with the valve seat 121, so that the valve disc 122 is opened, and at this time, steam in the steam inlet cavity 111 can enter the turbine through the gap between the valve disc 122 and the valve seat 121, the inner hole and the steam inlet hole 112. Meanwhile, the actuator 2 of the embodiment drives the valve rod 123 through the lever mechanism 3, and the mode of opening the valve disc 122 is realized, so that the output force of the required actuator 2 is small, the actuator 2 with small specification and type can meet the requirement, and the selection of the actuator 2 is facilitated. Meanwhile, in the embodiment, one end of the lever 32 is hinged to the supporting seat 31 through the roller 33, that is, the lever mechanism 3 is a roller type, so that the load of the actuating mechanism 2 is effectively reduced, and the operation stability of the steam inlet structure of the steam turbine is enhanced. The lever ratio of the lever mechanism 3 in this embodiment is usually not more than 3, and has good stability.

As shown in fig. 2, in the present embodiment, a mounting hole is formed in the valve body 11, a valve cover 13 having a through hole is mounted on the valve body 11, and an extending end 131 of the valve cover 13 is inserted into the mounting hole and extends into the steam inlet cavity 111; the valve rod 123 is arranged in the through hole of the valve cover 13 in a penetrating way, a bushing 132 sleeved on the valve rod 123 is arranged in the through hole of the valve cover 13, and a sleeve 133 is arranged at the extending end 131 of the valve cover 13. The bushing 132 installed in the through hole of the valve cap 13 not only plays a role of sealing and protecting, but also prevents a large gap from being formed between the valve cap 13 and the valve stem 123, thereby causing the valve stem 123 and the valve disc 122 to be easily vibrated and noisy under the excitation of unstable steam in the steam inlet cavity 111. Meanwhile, the sleeve 133 installed at the extension end 131 can effectively prevent the bushing 132 from falling out of the through hole, and plays a role in limiting and fixing the bushing 132. In addition, in this embodiment, the sleeve 133 is screwed to the extension end 131, so that the assembly between the sleeve 133 and the extension end 131 is facilitated, and the sleeve 133 is detachably connected to the extension end 131, so that the sleeve 133 can be conveniently detached when needed.

In this embodiment, sleeve 133 is provided with an upper positioning seal surface, and valve disc 122 is provided with a lower positioning seal surface, the upper positioning seal surface being adapted to mate with the lower positioning seal surface. In the process that the valve rod 123 drives the valve disc 122 to move away from the valve seat 121, the lower positioning sealing surface is matched with the upper positioning sealing surface to position the valve disc 122, the moving stroke of the valve disc 122 is limited, and the valve disc 122 is matched with the sleeve 133 in a sealing manner by utilizing the matching relationship between the lower positioning sealing surface and the upper positioning sealing surface, so that steam is prevented from flowing out from the position between the valve disc 122 and the valve cover 13.

As shown in fig. 2, in this embodiment, the inner walls of the sleeves 133 of the first regulating valve 101 and the third regulating valve 103 are provided with guide bushings 134, and the guide bushings 134 are sleeved outside the valve disc 122; guide bushing 134 guides valve disc 122 during movement of valve disc 122 in a direction away from and toward valve seat 121. And the sleeve 133 of the first regulating valve 101 and the third regulating valve 103 is provided with a groove, the inner wall surface of the groove forms an upper positioning sealing surface, the convex wall surface of the valve disc 122 of the first regulating valve 101 and the third regulating valve 103 forms a lower positioning sealing surface, and in the process that the valve disc 122 moves away from the valve seat 121, the convex of the valve disc 122 is embedded in the groove of the sleeve 133, so that the matching of the upper positioning sealing surface and the lower positioning sealing surface is realized, and the sealing matching between the sleeve 133 and the valve disc 122 and the limit of the valve disc 122 are realized. In this embodiment, the extension 131 of the valve cover 13 of the second and fourth regulators 102, 104 is fixedly installed with a guide bushing 134, and the guide bushing 134 is sleeved outside the valve disc 122.

As shown in fig. 2, the steam inlet structure of the steam turbine in this embodiment further includes a spring box 4 installed on the valve body 11, and the spring box 4 can apply a force to the valve rod 123 toward the steam inlet 112, so that the valve disc 122 is in a state of normally contacting with the valve seat 121, and when necessary, the actuator 2 drives the valve disc 122 to move away from the valve seat 121 through the valve rod 123. In the present exemplary embodiment, one spring box 4 is associated with each control valve 1, the spring box 4 being located above the valve cover 13.

The steam turbine steam inlet structure in the embodiment is suitable for a steam turbine adopting nozzle steam distribution, in particular to a steam inlet structure of a high-parameter and low-power steam turbine, and solves the problems that the selection of a servomotor is difficult, the stability is poor, the design difficulty of a cylinder is large and the like caused by the continuous improvement of steam parameters of a plate type structure on the premise. Meanwhile, the steam turbine steam inlet structure is particularly suitable for steam turbines started by adopting full parameters, and is particularly suitable for industrial steam turbines with steam inlet parameters not exceeding 13.24MPa and 566 ℃.

In this embodiment, the regulating valve 1 is disposed on the upper portion of the cylinder in a seat cylinder manner, and the valve body 11 and the steam turbine cylinder are integrated or fixed to the cylinder in a bolt connection manner. In the embodiment, all the regulating valves 1 are controlled by one or two actuators 2, and the valve cores 12 of all the regulating valves 1 are not completely identical in structure. The valve core 12 structure of the first regulating valve 101 and the third regulating valve 103 is suitable for high-parameter starting, the caliber of the valve disc 122 of the valve core 12 is small, the matching surface of the valve disc 122 and the valve seat 121 is a large-angle conical surface, namely the surface of a conical matching part, the conical angle of the conical matching part is 60-80 degrees, and the end part, namely the head part, of the valve disc 122 is a spherical part with a plane or a concave surface. The conical mating portion in this embodiment is located above the spherical portion. The valve cores 12 of the first regulating valve 101 and the third regulating valve 103 have smaller steam flow passing through under the same opening degree, the sensitivity of the valves to steam flow control under the small opening degree is improved, and the steam turbine control valve is particularly suitable for starting a steam turbine under high parameters. The bore sizes of the valve discs 122 of the second and fourth regulator valves 102, 104 are larger and the valve discs 122 are self-balancing valve discs with balancing holes.

As shown in fig. 2, in the present embodiment, each regulating valve 1 is provided with a separate valve cover 13, so that the stress level and the deformation of the cylinder port connected with the valve cover 13 are effectively reduced. Each sleeve 133 is fixed to the valve cap 13 independently provided to each control valve 1 by means of screw connection, and the valve cap 13 is mounted to the cylinder flange surface by means of bolts, and the extension 131 of the valve cap 13 is inserted into the cylinder opening and placed in the steam flow passage. In this embodiment, valve disc 122 and valve rod 123 are integrated, so that the connection rigidity and stability of valve rod 123 and valve disc 122 are improved, and the structure of valve element 12 is simpler. The middle of the valve cover 13 is provided with a through hole, the valve rod 123 penetrates through the through hole and is connected with a connecting rod 124 in the spring box 4, and the connecting rod 124 is connected with the lever 32.

As shown in fig. 2, in the present embodiment, the multiple regulating valves 1 adopt different valve cores 12, and the multiple regulating valves 1 can be flexibly grouped and controlled by one or two actuators 2, which facilitates the model selection of the actuators 2 with high parameters, and the valve cores 12 can be configured with self-balancing valve discs, thereby effectively reducing the valve lifting force. Only the valve core 12 part of the regulating valve 1 is positioned in a main flow area, the valve core 12 is compact in structure, fit gaps among all parts of the valve core 12 are small, and the stability of the valve is obviously improved. Each regulating valve 1 is provided with an independent valve cover 13, so that the stress level and the deformation of the opening of the cylinder are effectively reduced, and the design difficulty of the cylinder is effectively reduced. The steam inlet structure disclosed by the valve in the embodiment is specially provided with the small-caliber large-taper flushing and rotating valve, so that the control sensitivity of the valve to the steam flow under the small opening degree is effectively improved, and the steam inlet structure is particularly suitable for a steam turbine set which needs to be started under the high parameter.

As shown in fig. 2, in the present embodiment, a first regulating valve 101 and a third regulating valve 103 are in a group, a second regulating valve 102 and a fourth regulating valve 104 are in a group, each group of regulating valves 1 is connected with the same actuator 2 and controlled by the actuator 2, and the regulating valves 1 and the actuators 2 are connected through a lever mechanism 3. The main steam valve 5 is positioned at one side of the valve body 11, and the main steam valve 5 is connected with the valve body 11 in a welding mode. In this embodiment, the first regulating valve 101, the second regulating valve 102, the third regulating valve 103, and the fourth regulating valve 104 are distributed in sequence from left to right. The valve cores 12 of the first regulating valve 101 and the third regulating valve 103 are small-diameter and large-taper flushing and rotating valve cores, the matching surfaces of the valve disc 122 and the valve seat 121 are large-angle conical surfaces, the head of the valve disc 122 is a spherical part with a platform, and the guide bushing 134 is arranged outside the valve disc 122 to ensure the centering of the valve disc 122 in the moving process. The sleeve 133 of the first 101 and third 103 regulating valves has three functions: one is used as a fixing device of the guide bush 134, the other is used as a guide bush of the valve rod 123, and the third is used for forming a positioning sealing structure of the full-open position of the valve by matching a groove of the guide bush with a boss at the back of the valve disc 122. The valve cores 12 of the second regulating valve 102 and the fourth regulating valve 104 are large-diameter pressure self-balancing valve cores, balancing holes are formed in the valve disc 122, so that the front and back pressures of the valve disc 122 are self-balanced, a guide bushing 134 is arranged outside the valve disc 122, and the guide bushing 134 is fixed to the extension end 131 of the valve cover 13. The sleeve 133 of the second and fourth regulators 102, 104 serves two functions: one is a fixture that acts as a bushing 132 on valve stem 123 and the other is a locating seal that mates with a boss on the back of valve disc 122 on its underside to form the fully open position of the valve.

In conclusion, the present invention effectively overcomes various disadvantages of the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.