JP6692285B2 - Steam valve - Google Patents

Description

  Embodiments of the present invention relate to steam valves.

  The steam valve installed at the turbine inlet of the steam turbine includes a steam stop valve that prevents the inflow of steam when an abnormality occurs, and a steam control valve that adjusts the flow rate and the inflow speed of steam flowing into the turbine. Each steam valve has a mechanism for adjusting the opening. The mechanism includes a valve element, a valve rod, a spring receiver that is connected to the valve rod and moves together with the valve element, a drive device for moving the valve element in a direction to increase the opening degree of the valve element, and an opening degree of the valve element. It is composed of a rotating spring or the like for moving the valve body in the direction of decreasing the size. The rotary spring, one end of which is attached to the spring bearing, has one end fixed to a spring box that covers the spring bearing and the rotary spring. When the opening degree of the valve body is increased, the valve body is pushed up by the drive device, and the valve body moves in the same direction together with the connected spring bearing. At this time, the rotary spring contracts as the spring bearing moves. On the other hand, when the opening degree of the valve element is reduced, the spring bearing is pushed down by the elastic force of the rotary spring in the direction of reducing the opening degree, and the valve element moves together with the spring bearing.

  Further, an opening degree detection device that detects the opening degree of the valve body is provided on the surface of the spring receiver that faces the surface on which the rotary spring is installed. The opening degree detection device is fixed to a spring receiver and is a connection piece that extends in a direction that reduces the opening degree of the valve body, an iron core that is connected to the connection piece and extends in the same direction as the connection piece, and a detection that covers the outer peripheral surface of the iron core. Composed of parts. A coil is provided inside the detection unit, and when the spring bearing moves together with the valve body, the iron core moves following the movement of the spring bearing, and the magnetic flux penetrating the detection unit changes. An induced electromotive force is generated in the coil inside the detector due to the change in magnetic flux. The detection unit converts the induced electromotive force into a displacement amount and detects the opening degree of the valve body.

  However, when the spring receiver rotates due to the twisting of the rotary spring in the rotation direction, an unreasonable force is applied to the connecting piece fixed to the spring receiving, and the connecting piece may be broken. If the connecting piece breaks, it becomes impossible to detect the opening degree of the valve body thereafter.

  With respect to the above concerns, in the conventional opening degree detection device, the guide roller is provided at the side end portion of the spring receiver. Further, a groove portion is provided at a side end portion of a spring box that houses the rotary spring, and the guide roller is arranged so as to be inserted into the groove portion. With the above structure, the rotational force of the rotary spring contributes only to the rotation of the guide roller, and the spring bearing does not rotate. However, when the guide roller stops rotating due to damage to the guide roller, the rotational force of the rotary spring is applied to the spring receiver, and the connection piece is again subjected to an excessive force. Therefore, there is a demand for a steam valve that can detect the opening even when the spring bearing rotates.

Japanese Utility Model Publication 62-173505 JP 2012-97592 A JP-A-3-81504

  The problem to be solved by the present invention is to provide a steam valve capable of detecting the degree of opening even when the spring receiver rotates.

  In order to solve the above-mentioned problems, according to the embodiment of the present invention, a valve body that is movable by vertical movement of a rod to adjust the amount of steam introduced into a steam turbine, and an axis around the rod. A spring that is arranged so as to spirally cover and that moves the valve body in a closing direction; an end of the spring that is fixed; a spring bearing that is connected to the rod and is movable in the axial direction of the rod; In a steam valve comprising an opening detection device connected to a spring receiver to detect the amount of movement of the valve element, the opening detection device is connected to the spring receiver via a connection part, and the spring receiver is , A mechanism movable horizontally with respect to the connecting portion.

It is an overall schematic diagram of a steam valve concerning a first embodiment. It is the figure of the opening degree detection device of the main steam valve concerning a first embodiment, and the enlarged view of the detection part neighborhood is seen in (a) from the AA direction of Drawing 2 (a). An enlarged cross-sectional view of the vicinity of the detector is shown. It is an enlarged view of the detection part vicinity of the opening degree detection device of the main steam valve concerning a second embodiment. It is an enlarged view of the detection part vicinity of the opening degree detection device of the main steam valve concerning a third embodiment. It is the figure of the opening degree detection device of the main steam valve concerning a 4th embodiment, and the enlarged view of the detection part neighborhood is seen in (a) from the AA direction of Drawing 5 (a). An enlarged cross-sectional view of the vicinity of the detection part is shown in FIG. 5C, which is a side view of the spring box seen from the direction BB in FIG. It is a figure of the opening degree detecting device when a detection part is made into a sensor, Comprising: The enlarged view of the detection part vicinity is shown in (a), and the detection part vicinity seen from the BB direction of Fig.6 (a). FIG.

  Hereinafter, the steam valve according to the embodiment will be described.

(First embodiment)
The first embodiment will be described. FIG. 1 is an overall schematic diagram of a steam valve according to the first embodiment. The steam valve 1 according to the first embodiment includes a valve body 20, a valve rod 21, a rod 22, a rotary spring 30, a spring box 40, a drive device 50, a spring receiver 100, and an opening degree detection device. It is composed of 110.

  The steam flowing into the steam inlet 10 passes through the strainer 11, and impurities having a specific particle size or more are removed. The flow rate of the steam from which impurities have been removed is controlled by the valve body 20, and the steam is introduced into the steam turbine (not shown) from the steam outlet 12. The flow rate of steam is controlled by moving the valve body 20 in the axial direction of the valve rod 21 and adjusting the interval (opening) between the valve seat 13 and the valve body 20. Further, the valve body 20 is fully closed when an abnormality occurs, thereby blocking the inflow of steam into the steam turbine (not shown).

  A valve rod 21 is coupled to one end of the valve body 20. The rod 22 is connected to the other end of the valve rod 21. At this time, the valve rod 21 and the rod 22 are connected so that their axial directions coincide with each other, and move in the axial direction of the valve rod 21.

  The rotary spring 30 applies a force in the valve closing direction to the spring receiver 100 when reducing the opening degree (closing the valve). The rotary spring 30 has a spiral structure centered on the axial direction of the rod 22. One end thereof is connected to the spring bearing 100. The rotary spring 30 is housed in the spring box 40, and the other end of the rotary spring 30 is connected to the upper end surface 41 of the spring box 40.

  The drive device 50 is composed of a hydraulic piston and a hot water tank for storing oil, and moves the valve body 20 in a direction in which the opening degree is increased (valve opening) against the force that the rotary spring 30 is contracted by hydraulic pressure. Let The drive device 50 is installed at the end of the rod 22, and moves the valve body 20, the valve rod 21, and the spring receiver 100 in the valve opening direction via the rod 22.

  The spring receiver 100 is connected to the valve rod 21 and the rotary spring 30, and propagates the force received from the rotary spring 30 to the valve body 20, the valve rod 21, and the rod 22. The spring receiver 100 has a protrusion 101 through which the valve rod 21 penetrates and a connecting portion 102 on which the rotary spring 30 is installed. That is, the valve body 20, the valve rod 21, the rod 22, the rotary spring 30, and the spring receiver 100 are connected. The projection 101 of the spring receiver 100 projects from the upper end surface 41 of the spring box 40 with the axial direction of the rod 22 as the longitudinal direction. On the other hand, the connecting portion 102 of the spring receiver 100 has a fan-shaped structure centered on the axial direction of the rod 22, and its radial direction coincides with the radial direction of the rotary spring 30.

  The opening degree detection device 110 is fitted into the spring receiver 100, and one end thereof projects from the lower end surface of the spring box 40. The opening detection device 110 detects the amount of movement of the valve body 20 integrated with the spring receiver 100. Details will be described later.

  Next, the opening / closing operation of the valve body 20 will be described with reference to FIG. When the valve body 20 is opened, the drive device 50 moves the valve body 20 via the rod 22. At this time, the valve rod 21 and the connecting portion 102 of the spring bearing 100 are also moved, and the distance between the upper end surface 41 and the connecting portion of the spring bearing 100 is shortened. When the valve body 20 opens, the flow rate of steam flowing into the steam turbine increases.

  When the valve body 20 is closed, the oil of the drive device 50 is discharged and the drive force applied from the drive device 50 to the rod 22 is reduced. Then, the spring bearing 100 is moved in the valve closing direction by the elastic force applied from the rotary spring 30 to the connecting portion 102 of the spring bearing 100. At this time, the valve body 20 also moves via the spring bearing 100, the valve rod 21, and the rod 22. By closing the valve body 20, the steam flowing into the steam turbine is shut off.

  Next, the configuration of the opening degree detection device 110 and the operation of the opening degree detection device according to the first embodiment will be described with reference to FIG. 2A and 2B are diagrams of the opening degree detection device for the steam valve according to the first embodiment, in which FIG. 2A is an enlarged view of the vicinity of the detection portion, and FIG. 2B is a direction AA of FIG. 2A. The cross-sectional enlarged view of the detection part vicinity seen from is shown. The opening detection device 110 includes a connection piece 111, an iron core 112, and a detection unit 113.

  The spring bearing 100 and the iron core 112 are connected via a connecting piece 111. The connection piece 111 has a shape in which the valve closing direction is the longitudinal direction. The upper end 111a of the connection piece 111 is designed so that the cross-sectional area seen from the AA cross section is larger than that of the other portion of the connection piece 111. The spring receiver 100 has a groove portion 103 that is opened and cut in the horizontal direction, and the upper end surface 111a of the connection piece 111 is fitted in the groove portion 103 from the horizontal direction. An iron core 112 is connected to a side of the end of the connecting piece 111 facing the upper end 111a by using a coupling member. The iron core 112 extends from the end of the connection piece 111 in the valve closing direction in a longitudinal shape.

  The detection unit 113 detects an axial displacement amount of the iron core 112, that is, an axial displacement amount of the spring bearing 100 and the valve body 20 to which the iron core 112 is connected. The detection unit 113 has a hollow structure, and the iron core 112 penetrates through this hollow region. A coil is mounted inside the detection unit 113, and when the iron core 112 moves following the valve body 20 and the spring bearing 100, an induced electromotive force is generated in the coil inside the detection unit 113. The detection unit 113 converts the induced electromotive force into a displacement amount and detects the displacement amount of the valve body 20 and the spring bearing 100. The detector 113 is preferably fixed to the oil cylinder of the drive device 50.

  Here, when the valve body 20 opens, the elastic force that the spring receiver 100 receives from the rotary spring 30 has a component not only in the axial direction of the valve rod 21 but also in the rotational direction of the rotary spring. Therefore, as shown in FIG. 1A, in order to detect the opening degree even when a force is applied in the rotation direction, the lower end surface of the spring box 40 has a degree of relaxing the force applied in the rotation direction. A space 42 is provided. Further, as shown in FIG. 2B, the groove portion 103 of the spring receiver 100 has a horizontal cutting structure. The groove portion 103 has a gap to alleviate the force in the rotational direction applied to the connection piece 111 even when the upper end portion 111a of the connection piece 111 is fitted. By providing these structures, even when the spring receiver 100 rotates, the force applied to the connection piece 111 can be relaxed.

  According to the first embodiment described above, by providing a space in the circumferential direction of the spring receiver 100 and the spring box 40, the rotational force applied to the opening degree detection device 110 is mitigated even if the spring receiver 100 rotates. To do. By relaxing the force applied to the opening degree detection device 110, damage to the opening degree detection device 110 can be suppressed and the opening degree of the valve body 20 can be continuously detected. Further, by adopting a structure that relieves the force, the load applied to the rotary spring 30 and the spring receiver 100 can be suppressed.

  In addition, in order to further reduce the force applied to the opening degree detection device 110, a bearing or a roller may be installed in the groove 103 of the spring receiver 100. When the groove 103 is mounted on the spring receiver 100, the spring box 40 does not need to have the space 42.

(Second embodiment)
Next, a second embodiment will be described with reference to FIG. FIG. 3 is an enlarged view of the vicinity of the detection unit of the steam valve opening degree detection device according to the second embodiment. Note that description of portions similar to those of the first embodiment will be omitted. The opening detection device for a steam valve according to the second embodiment includes a valve body 20, a rotary spring 30, a spring box 40, a drive device 50, a spring receiver 200, and an opening detection device 210. . The second embodiment differs from the first embodiment in the structure of the spring bearing.

  The opening degree detection device 210 includes a connection piece 211, an iron core 212, and a detection unit 213. The connection piece 211 is fixed to the spring receiving lower end 202 and the lower end of the spring box 40. The upper end of the connection piece 211 has a screw thread and is fixed to the screw hole provided in the spring receiving lower end 202, but the fixing method is not limited. The iron core 211 and the detection unit 213 are the same as in the first embodiment.

  The spring receiver 200 is composed of a spring receiver upper end 201, a spring receiver lower end 202, and a roller 204. The spring bearing upper end portion 201 and the spring bearing lower end portion 202 are in contact with each other via a roller 204 in a recess 203 provided in the spring bearing lower end portion 202, and the spring bearing upper end portion 201 is in the recess portion 203 of the spring bearing lower end portion 202. Can be rotated on the circumference of. When the valve body 20 and the spring receiver 100 move in the valve closing direction, when a force is applied from the rotary spring 30 in the rotation direction, the spring receiver upper end portion 201 is rotated to relax the force in the rotation direction. Further, the connection piece 211 is connected to the surface of the lower end portion 202 of the spring receiver that faces the recess 203.

  According to the second embodiment described above, the spring bearing 200 is divided, and the spring bearing upper end portion 201 is rotatable with respect to the spring bearing lower end portion and the opening degree detection device 210. It has the same effect as the embodiment. Further, by fixing the opening degree detection device 210 to the spring bearing lower end portion 202, the opening degree detection device 210 can be welded and fixed to the spring bearing lower end portion 202. Therefore, the detection unit can be installed more stably than in the first embodiment.

(Third embodiment)
Next, a third embodiment will be described with reference to FIG. FIG. 4 is an enlarged view of the vicinity of the detection unit of the steam valve opening degree detection device according to the third embodiment. Note that description of portions similar to those of the first and second embodiments will be omitted. A steam valve opening detection device according to the third embodiment includes a valve body 20, a rotary spring 30, a spring box 40, a drive device 50, a spring receiver 300, and an opening detection device 310. . In the third embodiment, the spring bearing 300 does not include a groove portion, and a rotary spring 314 and an upper end portion 315 are further provided in a connecting portion between the detection unit and the spring bearing 310.

  The opening detection device 310 includes a detection unit (not shown), a connection piece 311, an iron core 312, a rotating spring 314, and an upper end 315.

  The iron core 312 penetrates the connection piece 311 and extends in a longitudinal direction in the axial direction of the rod 22. Further, the iron core 312 can move in the axial direction of the rod 22. A rotary spring 314 is provided in a spiral shape around the open core 312, and one end of the rotary spring 314 is connected to the connection piece 311. The other end of the rotary spring 314 and the iron core 312 are connected to the upper end portion 315. At this time, the rotary spring 314 is connected in a contracted state with respect to the axial direction of the rod 22. The upper end 315 contacts the spring receiver 300 via the upper end surface 315a. The shape of the upper end surface 315a is not limited and may be a flat surface as shown in FIG. 4 or may be a hemispherical surface, for example.

  Next, the operation of the steam valve opening degree detection device according to the third embodiment will be described. The drive device moves the valve body 20 in the valve opening direction via the valve rod 21, the rod 22, and the spring receiver 300. When the spring bearing 300 moves, the upper end portion 315 follows the spring bearing 300 by the elastic force received from the rotary spring 314. When the upper end 315 moves, the iron core 312 connected to the upper end 315 also follows and moves. On the other hand, when the spring receiver 300 moves in the valve closing direction by the rotating spring 30, the upper end portion 315 receives the force in the valve closing direction from the spring receiver 300 and moves following the valve body 20 and the spring receiver 300.

  Further, when the valve body 20 and the spring bearing 300 move in the valve closing direction, the opening degree detection device 310 and the spring bearing 300 contact each other via the upper end surface 315a. Therefore, even when the spring receiver 300 receives a force in the rotation direction from the rotary spring 30, the force is absorbed by the upper end surface 315a, and the force in the rotation direction propagating to the connection piece 311 and the iron core 312 is relaxed.

  According to the above-described third embodiment, the spring bearing 300 and the opening degree detection device 310 are brought into contact with each other via the upper end surface 315a, thereby suppressing the propagation of the force applied in the rotation direction. Has the same effect as. Further, since the spring receiver 300 and the opening degree detection device 310 are not fixed, replacement and attachment of the detection unit are easier than in the first embodiment.

  In addition, in the third embodiment, it is preferable that the connection piece 311 is connected to a side end portion of the valve body 20 as shown in FIG.

(Fourth embodiment)
Next, a fourth embodiment will be described with reference to FIG. FIG. 5: is a figure of the opening degree detection apparatus of the steam valve which concerns on 4th Embodiment, Comprising: (a) The enlarged view of the detection part vicinity is seen from the AA direction of (b) FIG. 5 (a). 5C is a side view of the spring box seen from the BB direction in FIG. 5B, and FIG. Note that description of portions similar to the first to third embodiments will be omitted. The steam valve opening detection device according to the fourth embodiment includes a valve body 20, a rotary spring 30, a spring box 40, a spring receiver 400, and an opening detection device 410. The fourth embodiment includes a plurality of connecting pieces, and has a structure in which the connecting piece 411b projects from the slit 43 of the spring box 40.

  The opening detection device 410 includes a connection piece 411a, a connection piece 411b, an iron core 412, and a detection unit 413. The connection piece 411a has a structure in which the axial direction of the valve body 20 is the longitudinal direction. On the other hand, the connection piece 411b has a structure in which the horizontal direction from the rotation center is the longitudinal direction, and one end of the connection piece 411b is fitted in the groove portion 401 of the spring receiver 400. The groove 401 is formed in the horizontal direction. The other end of the connection piece 411b projects from the slit 43 of the spring box 40 and is joined to the end of the connection piece 411a. The slit 43 of the spring box 40 extends in the axial direction of the valve body 20, and when the valve body 20 and the spring bearing 400 move in the axial direction, the connecting piece 411b follows the spring bearing 400 and the rod 22 of the rod 22 moves. It is movable along the axial direction. When the connecting piece 411b moves in the axial direction of the rod 22, the connecting piece 411a and the iron core 412 connected to the connecting piece 411b also follow. On the other hand, in the case where the valve body 20 and the spring receiver 400 move in the valve closing direction, when a force is applied from the rotary spring 30 in the rotation direction, the spring receiver 400 rotates and the rotation direction applied to the connection piece 411b changes. Relax the power.

  According to the above-described fourth embodiment, the connecting piece 411b is projected from the slit 43 of the spring box, and the detection unit 413 is arranged outside the spring box, so that the same effect as the fourth embodiment is obtained. Further, by utilizing the slit provided in the spring box 40, the spring box 40 can be attached to the existing steam valve without processing.

  In addition, in order to further reduce the force applied to the opening degree detection device 410, a bearing or roller may be installed in the groove portion 401 of the spring receiver 400. When the roller is installed in the groove 401, it is preferable to install the connecting piece 411b from the tip of the roller toward the outer side in the radial direction of rotation. In that case, even if the spring receiver 400 rotates, the roller itself does not rotate around the axis of the valve body 20, so that the force in the rotational direction applied to the connection piece 411b can be further alleviated.

  Furthermore, in the above-described fourth embodiment, when a roller is installed in the groove 401, for example, the detection unit may be a non-contact detection unit such as a sensor. This case will be described with reference to FIG. FIG. 6 is a diagram of an opening degree detection device in which the detection unit is used as a sensor. (A) An enlarged view of the vicinity of the detection unit is detected from the direction BB of FIG. 6 (a). An enlarged cross-sectional view of the vicinity of the portion is shown. When a sensor is used, a guide roller 420, a sensor 430, and a toothed plate 431 are provided instead of the opening degree detection device 410. The toothed plate 431 has an uneven portion along the longitudinal direction of the slit 43 of the spring box and is fixed to the spring box 40. The guide roller 420, the sensor 430, and the concavo-convex portion of the toothed plate 431 are arranged in a straight line in the horizontal direction.

  The sensor 430 irradiates the tooth-shaped plate 431 with light, and measures, for example, conditions for interference with reflected light and the time until detecting reflected light from the tooth-shaped plate 431. The radial distance from the sensor 430 to the concavo-convex portion of the tooth-shaped plate 431 changes depending on the axial position of the valve body 20, and thus the interference condition and the difference in the detection time of reflected light correspond to the displacement. Therefore, the displacement amount is detected by converting those values into displacement information. The sensor 430 is preferably mounted on the tip of the guide roller 420.

  With the structure using the sensor 430 described above, the guide roller 420 does not rotate around the axis of the valve body 20 even if the spring bearing 400 rotates, so that even if the spring bearing 400 rotates, it continues. The opening can be detected. Furthermore, since the structure is simpler and smaller than the conventional detection unit, it can be easily installed and removed.

  Further, the steam valves according to the above-described first to fourth embodiments have been described by taking the steam stop valve as an example, but the opening degree detection device may be mounted on the steam control valve.

  Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are also included in the invention described in the claims and the scope equivalent thereto.

1. Steam valve, 10. Steam inlet, 11. Strainer, 12. Steam outlet, 13. Valve seat, 20. Valve body, 21. Valve stem, 22. Rod, 30. Rotary spring, 40. Spring box, 41. Upper end surface, 42. Space part, 43. Slit, 50. Drive device, 100. Spring bearing, 101. Protrusion, 102. Connection part, 103. Groove, 110. Opening degree detection device, 111. Connection piece, 111a. Upper end surface, 112. Iron core, 113. Detector, 200. 201. Upper end of spring bearing 202. Spring receiving lower end portion, 203. Recess, 204. Laura, 210. Opening degree detection device, 211. Connection piece, 212. Iron core, 213. Detection unit, 300. Spring bearing, 310. Opening degree detection device 312. Iron core, 314. Rotary spring, 315. Upper end 315a. Upper end surface, 400. Spring bearing, 401. Groove, 410. Opening degree detection device, 411a. Connection piece 411b. Connection piece 412. Iron core, 413. Detection unit, 420. Guide roller, 430. Sensor, 431. Toothed plate

Claims (5)

A valve body that is movable by the vertical movement of the rod to adjust the amount of steam introduced into the steam turbine,
A spring that is arranged so as to spirally cover the axis of the rod and that moves the valve body in a closing direction,
An end portion of the spring is fixed, a spring bearing that is connected to the rod and is movable in the axial direction of the rod,
An opening degree detection device that is connected to the spring receiver and detects the amount of movement of the valve body,
In a steam valve equipped with
The opening degree detection device is connected to the spring receiver via a connection part,
The spring receiver is a steam valve including a mechanism that is movable in a horizontal direction with respect to the connection portion.   The steam valve according to claim 1, wherein the spring receiver is provided with a groove portion in a horizontal direction, and the connection portion is fitted in the groove portion such that the spring receiver is horizontally movable. The spring bearing has a spring bearing portion to which an end portion of the spring is fixed,
A recess that is fitted to the spring bearing so as to be movable in the horizontal direction and that is connected to the rod and is movable in the axial direction of the rod;
Further equipped with,
The steam valve according to claim 1, wherein the connecting portion is fixed to a surface of the recess facing the spring receiving portion. The steam valve covers the outer circumference of the spring and the spring receiver, and further comprises a spring box having a slit extending on the outer peripheral surface in the axial direction of the rod.
The spring bearing is provided with a groove in the horizontal direction,
The steam valve according to claim 1, wherein the connecting portion extends horizontally through the slit, and the connecting portion is fitted in the groove portion. The connection is
An abutting portion that comes into contact with a surface of the spring bearing that faces the spring, and that moves when the spring bearing moves in the axial direction of the rod, following the spring bearing;
An iron core connected to the contact portion, penetrating through the opening degree detecting device, extending longitudinally in the axial direction of the rod, and movable in the axial direction of the rod,
A rotating spring that covers the periphery of the iron core and is connected to the contact portion and the opening degree detection device,
The steam valve according to claim 1 , further comprising:

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