Steam admission regulating valve of turboset

Abstract

The invention discloses a steam admission regulating valve of a turboset. The steam admission regulating valve comprises a regulating valve assembly, a lever transmission mechanism and a hydraulic servo-motor, the adjusting valve assembly is provided with two valve rods, a valve beam, a plurality of valve disc assemblies, a plurality of valve seats and a valve deck, the valve rods and the valve disc assemblies connected with the valve beam are located in the steam inlet chamber, and two supporting rods are arranged on the valve deck. The lever transmission mechanism is provided with a lever main body section, a lever chaining section, two groups of lifting rods and a side pull rod, the lever main body section is hinged to one group of supporting rods, the lever chaining section is hinged to the other group of supporting rods, the lever chaining section and the lever main body section are hinged between the two groups of supporting rods, and the side pull rod is hinged between the lever main body section and the hydraulic servo-motor. One group of lifting rods is hinged between the lever main body section and one group of valve rods, and the other group of lifting rods is hinged between the lever chaining section and the other group of valve rods; the hydraulic servo-motor drives the adjusting valve assembly through the lever transmission mechanism. According to the invention, a power plant user can flexibly adjust the mounting position according to the actual arrangement direction of the steam pipeline.

Description

Technical Field

[0001] The invention relates to a steam turbine unit, in particular to a group type regulating valve structure for steam inlet control of the steam turbine unit. Background Art

[0002] In the structure of the steam turbine unit, the regulating valve is one of the key components for controlling the operation of the steam turbine unit. It is used to adjust and control the steam flow entering the flow part of the steam turbine unit so that the steam turbine unit can operate stably according to the technical requirements of the controlled parameters (power or speed, steam inlet pressure, back pressure, etc.).

[0003] Due to the control characteristics of the regulating valve on the operation of the steam turbine unit, it is necessary to design a larger structure of the regulating valve disc to adapt to the high-parameter, large-capacity steam turbine unit. However, as the valve disc structure increases, under the action of the main steam pressure, the valve disc will exert a large force on the valve stem of the regulating valve, which will directly increase the technical difficulty of the design of the regulating valve. For this reason, the industry has formed the regulating valves on high-parameter, large-capacity steam turbine units with a group structure, that is, based on the conventional small-structure regulating valve, multiple groups of mutually coordinated control are formed, thereby forming multiple groups of relatively independent regulating valves on a high-parameter, large-capacity steam turbine unit. In this way, since each group of regulating valves still adopts a conventional small structure, the force of the valve disc on the valve stem is controllable and easy to implement.

[0004] Since each group of regulating valves is composed of a regulating valve assembly (including a valve disc, a valve seat, a valve stem, etc.), a transmission mechanism and an oil motor, that is, the oil motor performs a one-to-one individual control of the regulating valve assembly through the transmission mechanism. According to the above-mentioned group-type regulating valve structure design logic, assuming that a high-parameter, large-capacity steam turbine unit has four relatively independent regulating valves, then in addition to installing four sets of regulating valve assemblies, the steam turbine unit also needs to install four oil motors and be equipped with four sets of transmission mechanisms. Obviously, this group-type regulating valve structure is not conducive to the compact structure of the steam turbine unit. On the one hand, it increases the floor area and space occupied by the whole machine; on the other hand, due to the large number of valve stems, the total steam leakage at each valve stem is large, and the number of steam leakage pipes that need to be formed is large; on the third hand, the hydraulic configuration structure of the oil motor is complicated. It can be seen that according to the design logic of the above-mentioned group-type regulating valve structure, it is not conducive to the compact structure of the steam turbine unit, which increases the manufacturing and construction costs, and is not conducive to gaining market favor.

[0005] In view of this, the industry has designed a group-type regulating valve in which a plurality of regulating valve assemblies are driven by a hydraulic motor through a transmission mechanism, such as the technology disclosed in the Chinese patent document entitled "A steam turbine regulating steam valve", with a publication number of CN 214617856 U and a publication date of November 5, 2021. In this technology, the valve disc assemblies of the plurality of regulating valve assemblies are assembled on the same valve beam, and the valve beam is connected to the two valve stems passing through the valve cover, and the hydraulic motor is connected to the two valve stems via a Y-shaped lever, so that the hydraulic motor drives the plurality of regulating valve assemblies via a transmission mechanism, which not only achieves the regulating and controlling effect of the group-type regulating valve on the steam turbine unit, but also greatly simplifies the forming structure of the group-type regulating valve, and the effect is remarkable. However, in this technology, the Y-shaped lever used directly determines that the arrangement position of the hydraulic motor relative to the steam inlet chamber is unique, that is, the hydraulic motor can only be fixedly installed on the cylinder on the lateral outer side of the steam inlet chamber, which is not conducive to the adaptive adjustment of the power plant users according to the actual arrangement direction of the steam pipeline, and the flexibility is poor. Summary of the invention

[0006] The technical purpose of the present invention is to provide a steam inlet regulating valve for a steam turbine unit which can achieve the regulating and controlling effect of a group-type regulating valve on the steam turbine unit and greatly simplify the molding structure of the group-type regulating valve in view of the particularity of the above-mentioned high-parameter, large-capacity steam turbine unit and the shortcomings of the prior art, and can relatively flexibly adjust the installation position according to the actual steam pipeline arrangement direction of the power plant user.

[0007] The technical purpose of the present invention is achieved through the following technical solution: a steam inlet regulating valve for a steam turbine unit, comprising a regulating valve assembly, a lever transmission mechanism and an oil motor; The regulating valve assembly comprises two sets of valve stems, a valve beam, multiple sets of valve disc assemblies, multiple sets of valve seats and a valve cover. The two sets of valve stems and the multiple sets of valve disc assemblies are assembled in parallel on the valve beam and are located in the steam inlet chamber of the cylinder. The multiple sets of valve seats are assembled in the steam inlet chamber. The multiple sets of valve disc assemblies on the valve beam and the multiple sets of valve seats are in a one-to-one matching relationship in the steam inlet chamber. The two sets of valve stems on the valve beam are respectively passed through the valve cover connected to the cylinder at the steam inlet chamber with a dynamic sealing structure. The lever transmission mechanism is hinged between the two groups of valve stems of the regulating valve assembly and the piston rod of the oil motor; The oil motor drives the regulating valve assembly through the lever transmission mechanism; On the valve cover of the regulating valve assembly, two groups of convex support rods are arranged at intervals along the length direction of the valve beam, and the convex positions of the two groups of support rods are located outside the two groups of valve stems installed on the valve cover; The lever transmission mechanism comprises a lever main section, a lever link section, two groups of lifting rods and a side pull rod, the middle part of the lever main section is hinged to a group of support rods on the valve cover, the outer end of the lever link section is hinged to another group of support rods on the valve cover, and the inner end of the lever link section and the inner end of the lever main section are hinged in the area between the two groups of support rods; One end of the side tie rod is hinged to the outer end of the lever main body section, and the other end of the side tie rod is hinged to the piston rod of the oil motor; One end of a group of lifting rods is hinged to the lever main body section, and the other end is connected to a group of valve stems of the regulating valve assembly; One end of another group of lifting rods is hinged to the lever linking section, and the other end is connected to another group of valve stems of the regulating valve assembly.

[0008] The above technical measures aim at the particularity of the above high-parameter and large-capacity steam turbine units, and the valve disc assemblies of multiple groups of regulating valve assemblies are assembled on the same valve beam, and the valve beam is used to connect the two groups of valve stems that pass through the valve cover. The oil motor is connected to the two groups of valve stems through the lever main section and the lever link section that are hinged in a straight line, so that one oil motor drives multiple groups of regulating valve assemblies through a group of transmission mechanisms. The above technical measures not only achieve the regulating and controlling effect of the group-type regulating valve on the steam turbine unit, but also greatly simplify the forming structure of the group-type regulating valve. At the same time, the lever main section and the lever link section that are hinged in a straight line can be replaced by the hinge position on the valve cover support rod, so that the oil motor can be installed on the cylinder on the left or right side of the steam inlet chamber. On the one hand, it is beneficial for the power plant user to relatively flexibly adjust the installation position according to the actual arrangement direction of the steam pipeline, and on the other hand, it is beneficial for the oil motor to be relatively safely arranged away from the high-temperature cylinder, and it can be applied to various control oil sources.

[0009] As one of the preferred technical solutions, the multiple valve disc assemblies of the regulating valve assembly have at least two installation structures with different lifting strokes on the valve beam; The lifting stroke of the valve disc assembly on the valve beam is adjusted by the limiting protrusion of the valve disc in the valve beam and the valve disc nut connected to the upper end of the valve disc passing through the valve beam.

[0010] The above technical measures are aimed at the assembly structure of multiple sets of valve disc assemblies on the same valve beam, forming a multi-level sequential pre-start control. While meeting the steam flow regulation, it is beneficial to reduce the force on the valve stem, thereby reducing the design technical difficulty of the lever transmission mechanism and the oil motor.

[0011] As one of the preferred technical solutions, the valve disc assembly comprises a pre-start valve disc and a large valve disc; The pre-start valve disc is installed in the corresponding through hole of the valve beam with a limit stop structure and extends upward. The upper end of the pre-start valve disc extending from the valve beam is connected with a valve disc nut. The lower part of the pre-start valve disc used for connecting the large valve disc is a key tooth structure arranged at a circumferential spacing. The large valve disc is used to seal with the corresponding valve seat in the steam inlet chamber; The large valve disc has an inner hole for installing the pre-start valve disc, the upper part of the inner hole of the large valve disc is a key tooth structure arranged at a circumferential interval, and the lower part of the inner hole of the large valve disc is provided with at least one pin hole facing the key tooth gap; The pre-start valve disc is axially installed in the inner hole of the large valve disc with a key tooth installation structure, and the key teeth of the pre-start valve disc are located below the corresponding key teeth of the large valve disc. The pin hole of the large valve disc is connected with an anti-rotation pin that radially extends into and is inserted between adjacent key teeth of the pre-start valve disc.

[0012] Furthermore, the bottom of the key teeth in the inner hole of the large valve disc is an inclined surface structure; The top of the key teeth of the pre-start valve disc is an inclined surface structure; When the large valve disc is seated and sealed on the corresponding valve seat in the steam inlet chamber, the valve beam is located at the upper end of the large valve disc, and there is a matching gap between the top of the key tooth of the pre-start valve disc and the bottom of the corresponding key tooth of the large valve disc.

[0013] Furthermore, the installation position of the pre-start valve disc in the valve beam is a non-circular structure that prevents rotation.

[0014] Furthermore, the pre-start valve disc and the large valve disc are respectively of full forging structures.

[0015] The valve disc assembly of the above technical measures forms a pre-start structure. When opening, the large valve disc can only be opened after the pre-start valve disc is pre-opened, which can effectively adjust the steam flow and effectively reduce the force on the valve stem. In order to avoid the influence of the steam flow excitation force of the flowing steam on the valve disc assembly, the valve disc assembly of the above technical measures uses a full forging structure to strengthen the forming of the pre-start valve disc and the large valve disc, and forms an anti-rotation design by installing the pre-start valve disc in the non-circular structure of the valve beam, which has excellent anti-steam flow interference performance and good durability.

[0016] As one of the preferred technical solutions, each group of valve seats of the regulating valve assembly is respectively installed between the steam inlet chamber and the nozzle chamber through a valve seat sealing ring of a laminated structure. The valve seat of this technical measure is stably assembled between the steam inlet chamber and the nozzle chamber and has good sealing performance.

[0017] As one of the preferred technical solutions, the regulating valve further includes a pre-tightening mechanism; The pre-tightening mechanism comprises a guide rod protruding from the top center of the valve cover, and a spring support plate, a coil spring, a spring pressure plate and a clamping nut are sequentially installed on the guide rod from bottom to top; The two ends of the spring support plate are correspondingly connected with the upper ends of the two groups of valve stems of the regulating valve assembly.

[0018] Furthermore, the connection between the spring support plate and the two groups of valve stems of the regulating valve assembly is hinged correspondingly to the two groups of lifting rods of the lever transmission mechanism.

[0019] Furthermore, a limiting ring groove is provided on the top of the spring support plate for the lower end of the coil spring to sit on; The coil spring sleeved on the guide rod is located in the limiting ring groove of the spring support plate.

[0020] The above technical measures are aimed at the phenomenon that the steam pressure in the steam inlet chamber generates buoyancy on the valve stem. The spring preload mechanism installed at the center of the valve cover generates force on the valve stem to overcome the buoyancy generated by the steam pressure in the steam inlet chamber on the valve stem, effectively preventing the regulating valve from opening automatically under the action of steam pressure. Compared with the technology of publication number CN 214617856 U, the spring preload mechanism is located in the center of the valve cover. On the one hand, the connection structure with the valve stem is simple and stable, and on the other hand, the force on the valve stem is clear and stable, which reduces the design technical difficulty of the entire regulating valve.

[0021] In addition, the matching structure of the valve cover and the coil spring of the above technical measures can enable the coil spring to form a stable and anti-slip arrangement around the guide rod connected to the valve cover, reliably avoiding changes in its preload force due to slippage of the coil spring.

[0022] The beneficial technical effect of the present invention is that the above technical measures not only achieve the regulating and controlling effect of the group-type regulating valve on the steam turbine unit, but also greatly simplify the molding structure of the group-type regulating valve. At the same time, it is beneficial for power plant users to relatively flexibly adjust the installation position according to the actual layout direction of the steam pipeline, and it is also beneficial for the oil motor to be relatively safely arranged away from the high-temperature cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention (the lever transmission mechanism and the oil motor are not shown).

[0024] Figure 2 It is a schematic diagram of the matching structure of the valve disc assembly, the lever transmission mechanism and the oil motor of the present invention.

[0025] Figure 3 for Figure 2 Top view of the .

[0026] Figure 4 for Figure 1 A partial enlarged view of the valve beam and valve disc assembly at AA.

[0027] Figure 5 for Figure 4 A partial enlarged view of the BB.

[0028] Figure 6 for Figure 4 A partial enlarged view of the CC.

[0029] The meaning of the codes in the figure are as follows: 1—regulating valve assembly; 11—valve stem; 12—valve beam; 13—valve seat; 14—valve cover; 15—support rod; 16—pre-start valve disc; 17—large valve disc; 18—anti-rotation pin; 19—valve disc nut; 110—ring; 2—lever transmission mechanism; 21—lever main section; 22—lever connecting section; 23—lifting rod; 24—side pull rod; 3—pre-tightening mechanism; 31—guide rod; 32—spring support plate; 33—helical spring; 34—spring pressure plate; 35—pressure nut; 4—oil motor; 41—mounting bracket; 42—piston rod; 5—cylinder; 51—steam inlet chamber; 52—nozzle chamber; 53—valve stem steam leakage pipe. DETAILED DESCRIPTION

[0030] The present invention relates to a steam turbine unit, and more particularly to a group type regulating valve structure for steam inlet control of a steam turbine unit. Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 The technical solution of the present invention is explained clearly and in detail.

[0031] It should be noted that the drawings of the present invention are schematic, and unnecessary details have been simplified to clarify the technical purpose of the present invention, so as to avoid blurring the technical solution of the present invention that contributes to the prior art. In addition, the expressions "approximately", "substantially" and the like regarding quantity or matching relationship in the following text mean that reasonable assembly errors and processing errors in the industry are allowed to exist, and do not literally express absolute quantities or matching relationships.

[0032] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the steam inlet regulating valve of the present invention comprises a regulating valve assembly 1, a lever transmission mechanism 2, a pre-tightening mechanism 3 and an oil motor 4.

[0033] The regulating valve assembly 1 comprises two groups of valve stems 11 , a valve beam 12 , four groups of valve disc assemblies, four groups of valve seats 13 and a valve cover 14 .

[0034] Specifically, the valve beam 12 is used to install four groups of valve disc assemblies and two groups of valve stems 11, so the installation channels of four groups of valve disc assemblies and two groups of valve stems 11 are arranged in the length direction of the valve beam 12. The installation channels of the four groups of valve disc assemblies basically form an evenly spaced arrangement, and the installation channels of the two groups of valve stems 11 basically form a left-right symmetrical arrangement.

[0035] Four sets of valve disc assemblies are installed side by side on the valve beam 12 at intervals along the length direction of the valve beam 12, two sets of valve stems 11 are installed side by side on the valve beam 12 at intervals along the length direction of the valve beam 12, and the four sets of valve disc assemblies and the two sets of valve stems 11 are arranged in parallel along the length direction of the valve beam 12. The valve beam 12 connected with the two sets of valve stems 11 and the four sets of valve disc assemblies is installed in the steam inlet chamber 51 of the cylinder 5, the sealing ends of the four sets of valve disc assemblies face the bottom of the steam inlet chamber 51, and the operating ends of the two sets of valve stems 11, i.e., the upper ends, extend out of the steam inlet chamber 51.

[0036] In order to reduce the stress on the valve stem 11 and reduce the design technical difficulty of the lever transmission mechanism 2 and the oil motor 4, the valve disc assembly connected to the valve beam 12 is a pre-start structure, having a pre-start valve disc 16 and a large valve disc 17. The pre-start valve disc 16 and the large valve disc 17 respectively adopt a full forging structure with excellent stress performance.

[0037] The installation part of the pre-start valve disc 16 is installed in the corresponding perforation of the valve beam 12 with a limit convex stop structure and extends upward. The upper end of the pre-start valve disc 16 extending through the valve beam 12 is connected with a valve disc nut 19. The lifting stroke of the pre-start valve disc 16 is adjusted by the limit convex stop of the pre-start valve disc 16 in the valve beam 12 and the valve disc nut 19 connected to the upper end of the pre-start valve disc 16 passing through the valve beam 12. A collar 110 is connected at the upper end of the valve disc installation channel on the valve beam 12. In order to prevent the pre-start valve disc 16 from rotating in the perforation of the valve beam 12 under the action of the steam pressure in the steam inlet chamber 51, the installation part of the pre-start valve disc 16 in the valve beam 12, that is, the part between the limit convex stop and the upper end thread, has a non-circular structure for preventing rotation in cross section. In this embodiment, it is a waist-shaped contour structure. Of course, other non-circular structures can also be used for forming, such as rectangle, hexagon, ellipse, etc. The lower end of the pre-start valve disc 16 is used to connect to the large valve disc 17, and the lower side of the pre-start valve disc 16 used to connect to the large valve disc 17 is a key tooth structure arranged at a circumferential spacing.

[0038] The large valve disc 17 is used to seal with the corresponding valve seat 13 in the steam inlet chamber 51, so the large valve disc 17 and the corresponding valve seat 13 are grinded and sealed. The large valve disc 17 has an inner hole for the pre-start valve disc 16. The upper part of the inner hole of the large valve disc 17 is a key tooth structure arranged at a circumferential spacing, and the key tooth structure at the upper part of the inner hole of the large valve disc 17 and the key tooth structure at the lower part of the pre-start valve disc 16 form a staggered matching relationship. In order to prevent the combined large valve disc 17 from falling off from the pre-start valve disc 16, two pin holes facing the key tooth gap of the large valve disc 17 are provided at the lower part of the inner hole of the large valve disc 17.

[0039] The pre-start valve disc 16 is axially installed in the inner hole of the large valve disc 17 with a key-tooth staggered installation structure, and a key-tooth position circumferential rotation is generated between the pre-start valve disc 16 and the large valve disc 17 that are installed in place, so that the key teeth of the pre-start valve disc 16 are located below the corresponding key teeth of the large valve disc 17. At this time, two anti-rotation pins 18 that radially extend into and are inserted between each adjacent key tooth of the pre-start valve disc 16 are respectively connected to the two pin holes of the large valve disc 17 with a threaded connection relationship, so that the large valve disc 17 and the pre-start valve disc 16 are combined and connected together.

[0040] In order to control the pre-start matching relationship between the pre-start valve disc 16 and the large valve disc 17 combined together, the key teeth bottom in the inner hole of the large valve disc 17 is an inclined surface structure, and the key teeth top of the pre-start valve disc 16 is an inclined surface structure. When the large valve disc 17 is seated and sealed on the corresponding valve seat 13 in the steam inlet chamber 51, the bottom of the valve beam 12 is located at the upper end of the large valve disc 17. At this time, there is a matching gap e between the key teeth top of the pre-start valve disc 16 and the corresponding key teeth bottom of the large valve disc 17, and e is not equal to 0.

[0041] Since the four sets of valve disc assemblies are assembled on the same valve beam 12, in order to control the differential opening of the four sets of valve disc assemblies and reduce the force of the steam in the steam inlet chamber 51 on the valve stem 11, the above-mentioned valve disc assemblies form two different lifting strokes on the valve beam 12, and the two sets of valve disc assemblies arranged alternately have the same lifting stroke. As described above, the lifting stroke of the valve disc assembly on the valve beam 12 is adjusted by the limiting protrusion of the pre-start valve disc 16 in the valve beam 12 and the valve disc nut 19 connected to the upper end of the pre-start valve disc 16 passing through the valve beam 12, thereby forming the following two lifting strokes: For the valve disc assembly with a larger lifting stroke, when the large valve disc 17 is seated and sealed on the corresponding valve seat 13 in the steam inlet chamber 51, the bottom of the valve beam 12 is seated on the upper end of the large valve disc 17. At this time, a matching gap d is formed between the valve disc nut 19 connected to the upper end of the pre-start valve disc 16 and the sleeve 110 at the installation channel of the valve beam 12, and d is not equal to 0; For the valve disc assembly with a smaller lifting stroke, when the large valve disc 17 is seated and sealed on the corresponding valve seat 13 in the steam inlet chamber 51, the bottom of the valve beam 12 is seated on the upper end of the large valve disc 17. At this time, there is no matching gap between the valve disc nut 19 connected to the upper end of the pre-start valve disc 16 and the ring 110 at the valve beam 12 for the installation channel.

[0042] Four sets of valve seats 13 are assembled in the steam inlet chamber 51, and each set of valve seats 13 is respectively installed between the bottom of the steam inlet chamber 51 and the top of the nozzle chamber 52 through a valve seat sealing ring of a laminated structure. The assembly positions of the four sets of valve seats 13 in the steam inlet chamber 51 form a one-to-one matching relationship with the four sets of valve disc assemblies connected to the valve beam 12 in the steam inlet chamber 51.

[0043] The valve cover 14 is sealed and connected to the cylinder 5 at the steam inlet chamber 51 through a plurality of screws with cover nuts. The valve cover 14 is provided with passages for two groups of valve stems 11 to pass through. Each group of valve stems 11 connected to the valve beam 12 passes through the valve cover 14 connected to the cylinder 5 at the steam inlet chamber 51 in a dynamic sealing structure. In order to reduce the amount of steam in the steam inlet chamber 51 that leaks from the valve stem 11 passing through, the valve stem passing passage on the valve cover 14 is filled with a sealing component. On the inner wall of the sealing component, a plurality of annular grooves arranged at intervals are provided along the height direction. The flying chips generated during the dynamic sealing process of the valve stem 11 can be collected by the annular ring, that is, the inner wall of the sealing component forms a plurality of chip removal annular grooves, which is conducive to eliminating the risk of the valve stem 11 being stuck while ensuring the sealing effect. In addition, due to the dynamic sealing fit between the valve stem 11 and the corresponding valve stem insertion channel of the valve cover 14, a gap channel for leaking steam will be formed to a greater or lesser extent, resulting in steam leakage. To improve this phenomenon, a valve stem steam leakage pipe 53 is connected to the valve stem insertion channel at the valve cover 14, and the steam collected through the valve stem steam leakage pipe 53 is connected to the steam-water pipeline of the steam turbine unit.

[0044] The above is the main body structure of the regulating valve assembly and its assembly structure with the steam inlet chamber 51 of the cylinder 5 .

[0045] The lever transmission mechanism 2 is hinged between the two groups of valve stems 11 of the above-mentioned regulating valve assembly 1 and the piston rod 42 of the oil motor 4. The lever transmission mechanism 2 has a group of lever main sections 21, a group of lever connecting sections 22, two groups of lifting rods 23, and a group of side pull rods 24.

[0046] Specifically, in order to adapt to the fulcrum support arrangement of the lever main section 21 and the lever link section 22 of the lever transmission mechanism 2, on the valve cover 14 of the above-mentioned regulating valve assembly 1, two groups of protruding support rods 15 are arranged at intervals along the length direction of the valve beam 12, and the protruding positions of the two groups of support rods are located on the outside of the two groups of valve stems 11 installed on the valve cover 14, basically forming a left-right symmetrical matching relationship on the valve cover 14.

[0047] The middle part of the lever main section 21 is hinged to the upper end of a group of support rods 15 on the valve cover 14 through a pin with a bearing or a sleeve. The outer end of the lever link section 22 is hinged to the upper end of another group of support rods 15 on the valve cover 14 through a pin with a bearing or a sleeve, and the inner end of the lever link section 22 and the inner end of the lever main section 21 are hinged at the center area between the two groups of support rods 15 through a pin with a bearing or a sleeve.

[0048] The upper end of the side tie rod 24 is hinged to the outer end of the lever main section 21 through a pin with a bearing or a sleeve. The lower end of the side tie rod 24 is hinged to the piston rod 42 of the oil motor 4 through a pin with a bearing or a sleeve. The oil motor 4 is installed on the cylinder 5 at the end of the steam inlet chamber 51 through a mounting bracket 41. Based on the hinge structure of the lever of the above-mentioned I-shaped hinge structure on the two groups of support rods 15 on the valve cover 14, the position of the lever and the side tie rod 24 can be exchanged to realize the installation of the oil motor 4 on the cylinder 5 at the left or right end of the steam inlet chamber 51, which greatly facilitates the flexibility of the power plant user to adjust according to the actual direction of the steam pipeline.

[0049] The upper end of a group of lifting rods 23 is hinged to the above-mentioned lever main section 21 through a pin shaft with a bearing or a sleeve, and is basically located in the central area between the support rod 15 connected to the lever main section 21 and the inner end of the lever main section 21; the lower end of this group of lifting rods 23 is connected to a group of valve stem 11 operating ends of the above-mentioned regulating valve assembly 1, that is, the end that passes through the valve cover 14, through a pin shaft with a bearing or a sleeve. The specific connection structure is shown in the matching structure of the spring support plate 32, the valve stem 11 and the lifting rod 23 described below. The upper end of another set of lifting rods 23 is hinged to the lever connecting section 22 through a pin with a bearing or a sleeve, and is basically located in the central area of ​​both ends of the lever connecting section 22; the lower end of this set of lifting rods 23 is connected to the operating end of another set of valve stems 11 of the above-mentioned regulating valve assembly 1, that is, the end that passes through the valve cover 14, through a pin with a bearing or a sleeve. The specific connection structure is shown in the matching structure of the spring support plate 32, the valve stem 11 and the lifting rod 23 described below.

[0050] According to the connection between the regulating valve assembly 1 and the oil motor 4 by the lever transmission mechanism 2, the oil motor 4 is arranged at the end of the steam inlet chamber 51 in a compact side position. Under the signal command, the oil motor 4 drives the regulating valve assembly 1 to lift and open through the lever transmission mechanism 2 of the straight hinge structure.

[0051] The pretensioning mechanism 3 comprises a guide rod 31 , a spring support plate 32 , a coil spring 33 , a spring pressure plate 34 and a pressure nut 35 .

[0052] Specifically, the lower end of the guide rod 31 of the preload mechanism 3 is fixedly connected to the center of the top of the valve cover 14 of the regulating valve assembly 1 and is formed to bulge upward at the center of the top of the valve cover 14 .

[0053] The spring support plate 32, the coil spring 33, the spring pressure plate 34 and the clamping nut 35 are sequentially installed on the guide rod 31 from bottom to top. In order to ensure the stability of the installation of the coil spring 33, a limiting ring groove for the lower end of the coil spring 33 to sit is provided on the top side of the spring support plate 32. The coil spring 33 sleeved on the guide rod 31 is seated in the limiting ring groove of the spring support plate 32, and basically forms a coaxial sleeve fit with the guide rod 31.

[0054] The two ends of the spring support plate 32 are respectively provided with through holes for the two groups of valve stems 11 of the regulating valve assembly 1 to pass through, that is, the two ends of the spring support plate 32 are correspondingly connected with the operating ends of the two groups of valve stems 11 of the regulating valve assembly 1, and the end of each group of valve stems 11 passing through the spring support plate 32 is locked by a nut. In order to ensure that the nut locks the spring support plate 32 on the valve stem 11, the valve stem 11 is passed through the corresponding end of the spring support plate 32 with a limiting convex stop structure. The connection between the spring support plate 32 and the two groups of valve stems 11 of the regulating valve assembly 1 is respectively hinged with the two groups of lifting rods 23 of the lever transmission mechanism 2 through pins with bearings or bushings, that is, the end of the spring support plate 32 is provided with a pin hole for passing the pin. In order to ensure the stability of the force, there are two groups of pin holes at each end of the spring support plate 32, which are basically formed on the inner and outer sides of the valve stem through-hole at this end in a left-right symmetrical structure.

[0055] The above specific technical solutions are only used to illustrate the present invention rather than to limit it.

[0056] Although the present invention is described in detail with reference to the above specific technical solutions, those skilled in the art should understand that they can still modify the above specific technical solutions, or replace some of the technical features therein, such as adjusting the arrangement number of valve disc assemblies on the valve beam, or adjusting the structure of the valve disc assemblies, etc. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the present invention.

Claims

1. A steam inlet regulating valve for a steam turbine unit, comprising a regulating valve assembly (1), a lever transmission mechanism (2) and an oil motor (4); The regulating valve assembly (1) comprises two sets of valve stems (11), a valve beam (12), multiple sets of valve disc assemblies, multiple sets of valve seats (13) and a valve cover (14); the two sets of valve stems (11) and the multiple sets of valve disc assemblies are assembled in parallel on the valve beam (12) and are located in a steam inlet chamber (51) of the cylinder (5); the multiple sets of valve seats (13) are assembled in the steam inlet chamber (51); the multiple sets of valve disc assemblies on the valve beam (12) and the multiple sets of valve seats (13) are in a one-to-one matching relationship in the steam inlet chamber (51); the two sets of valve stems (11) on the valve beam (12) are respectively passed through the valve cover (14) connected to the cylinder (5) at the steam inlet chamber (51) by means of a dynamic sealing structure; The lever transmission mechanism (2) is hinged between two groups of valve stems (11) of the regulating valve assembly (1) and the piston rod (42) of the oil motor (4); The oil motor (4) drives the regulating valve assembly (1) via the lever transmission mechanism (2); Features: On the valve cover (14) of the regulating valve assembly (1), two groups of protruding support rods (15) are arranged at intervals along the length direction of the valve beam (12), and the protruding positions of the two groups of support rods are located outside the two groups of valve stems (11) installed on the valve cover (14); The lever transmission mechanism (2) comprises a lever main section (21), a lever link section (22), two groups of lifting rods (23), and a side pull rod (24); the middle portion of the lever main section (21) is hinged to a group of support rods (15) on the valve cover (14); the outer end of the lever link section (22) is hinged to another group of support rods (15) on the valve cover (14); the inner end of the lever link section (22) and the inner end of the lever main section (21) are hinged in the area between the two groups of support rods (15); One end of the side tie rod (24) is hinged to the outer end of the lever main body section (21), and the other end of the side tie rod (24) is hinged to the piston rod (42) of the oil motor (4); One end of a group of lifting rods (23) is hinged to the lever main body section (21), and the other end is connected to a group of valve stems (11) of the regulating valve assembly (1); One end of another set of lifting rods (23) is hinged to the lever link section (22), and the other end is connected to another set of valve stems (11) of the regulating valve assembly (1).

2. The steam inlet regulating valve for a steam turbine unit according to claim 1, characterized in that: The multiple sets of valve disc assemblies of the regulating valve assembly (1) have at least two installation structures with different lifting strokes on the valve beam (12); The lifting stroke of the valve disc assembly on the valve beam (12) is adjusted by a limiting protrusion of the valve disc in the valve beam (12) and a valve disc nut (19) connected to the upper end of the valve disc passing through the valve beam (12).

3. The steam inlet regulating valve for a steam turbine unit according to claim 1 or 2, characterized in that: The valve disc assembly comprises a pre-start valve disc (16) and a large valve disc (17); The pre-start valve disc (16) is installed in the corresponding through hole of the valve beam (12) with a limiting convex stop structure and extends upwards; the upper end of the pre-start valve disc (16) that is installed and extends out of the valve beam (12) is connected to a valve disc nut (19); the lower part of the pre-start valve disc (16) used for connecting to the large valve disc (17) is a key tooth structure arranged at a circumferential interval; The large valve disc (17) is used to seal with a corresponding valve seat (13) in the steam inlet chamber (51); The large valve disc (17) has an inner hole for inserting the pre-start valve disc (16), the upper side of the inner hole of the large valve disc (17) is a key tooth structure arranged at a circumferential spacing, and the lower side of the inner hole of the large valve disc (17) is provided with at least one pin hole facing the key tooth gap; The pre-start valve disc (16) is axially installed in the inner hole of the large valve disc (17) by means of a key tooth installation structure, and the key teeth of the pre-start valve disc (16) are located below the corresponding key teeth of the large valve disc (17), and the pin hole of the large valve disc (17) is connected with an anti-rotation pin (18) which radially extends into and is inserted between adjacent key teeth of the pre-start valve disc (16).

4. The steam inlet regulating valve for a steam turbine unit according to claim 3, characterized in that: The bottom of the key teeth in the inner hole of the large valve disc (17) is an inclined surface structure; The top of the key tooth of the pre-start valve disc (16) is an inclined surface structure; When the large valve disc (17) is seated and sealed on the corresponding valve seat (13) in the steam inlet chamber (51), the valve beam (12) is located on the upper end of the large valve disc (17), and a matching gap exists between the top of the key tooth of the pre-start valve disc (16) and the bottom of the corresponding key tooth of the large valve disc (17).

5. The steam inlet regulating valve for a steam turbine unit according to claim 3, characterized in that: The pre-start valve disc (16) is installed in the valve beam (12) at a position that is non-circular and has an anti-rotation structure.

6. The steam inlet regulating valve for a steam turbine unit according to claim 3, characterized in that: The pre-start valve disc (16) and the large valve disc (17) are both fully forged structures.

7. The steam inlet regulating valve for a steam turbine unit according to claim 1, characterized in that: Each group of valve seats (13) of the regulating valve assembly (1) is respectively installed between the steam inlet chamber (51) and the nozzle chamber (52) via a valve seat sealing ring of a laminated structure.

8. The steam inlet regulating valve for a steam turbine unit according to claim 1, characterized in that: The regulating valve also includes a pre-tightening mechanism (3); The preload mechanism (3) comprises a guide rod (31) protruding from the top center of the valve cover (14), and a spring support plate (32), a coil spring (33), a spring pressure plate (34) and a clamping nut (35) which are sequentially mounted on the guide rod (31) from bottom to top; The two ends of the spring support plate (32) are correspondingly connected to the upper ends of the two groups of valve stems (11) of the regulating valve assembly (1).

9. The steam inlet regulating valve for a steam turbine unit according to claim 8, characterized in that: The connection between the spring support plate (32) and the two groups of valve stems (11) of the regulating valve assembly (1) is correspondingly hinged to the two groups of lifting rods (23) of the lever transmission mechanism (2).

10. The steam inlet regulating valve for a steam turbine unit according to claim 8 or 9, characterized in that: The top of the spring support plate (32) is provided with a limiting ring groove for the lower end of the coil spring (33) to sit on; The coil spring (33) sleeved on the guide rod (31) is located in the limiting ring groove of the spring support plate (32).

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