JP6996968B2 - Steam stop valve, steam turbine - Google Patents

Description

The present invention relates to a steam stop valve and a steam turbine.

The steam flow path that supplies steam to the steam turbine is equipped with a steam stop valve. The steam stop valve instantly shuts off the inflow of steam into the steam turbine in an emergency.

For example, as disclosed in Patent Document 1, the steam stop valve may include a casing, a valve body, a swing arm, and an arm drive unit. The casing of Patent Document 1 includes a steam flow path portion and a valve accommodating portion. The steam flow path portion is formed in a cylindrical shape (barrel shape), and steam flows inside the cylinder shape. The valve accommodating portion is formed so as to be recessed in a direction intersecting the direction in which steam flows. The swing arm is rotatably supported around the axis of a rotating shaft whose first end is fixed to the casing. The second end of the swing arm is connected to the valve body. The valve body rotates together with the swing arm around the first end of the swing arm. The valve body is rotatable between a closed position that closes the steam flow path portion and an accommodation position that is accommodated in the valve accommodating portion. The arm drive unit includes a hydraulic actuator or the like, and rotates the swing arm to move the valve body from the accommodating position to the closed position.

Japanese Unexamined Patent Publication No. 2012-2249

In the steam stop valve described in Patent Document 1, in normal times, the valve body is held in the accommodation position in the valve accommodation portion by the pressure applied by the arm drive portion. When the valve body is in the accommodation position, a part of the steam flowing through the steam flow path part flows into the back surface side of the valve body opposite to the steam flow path portion, and the pressure acting on the back surface side of the valve body increases. May be done. If the pressure acting on the back surface side of the valve body exceeds the pressure applied by the hydraulic actuator of the arm drive unit or the like, the valve body may be moved from the accommodating position to the closed position.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a steam stop valve and a steam turbine capable of suppressing the movement of a valve body toward a closed position when unnecessary.

The present invention employs the following means in order to solve the above problems.
According to the first aspect of the present invention, the steam stop valve includes a flow path forming portion forming a steam flow path portion through which steam flows, a casing having a valve accommodating portion recessed from the steam flow path portion, and the valve accommodating portion. A rotation axis that intersects the steam flow direction in the steam flow path portion and a first end portion are rotatably supported around the rotation axis, and the first end portion to the second end portion are rotatably supported. By being fixed to the swing arm extending toward the portion, the driving portion for rotating the swing arm around the rotation axis, and the second end portion of the swing arm, and rotating together with the swing arm, the swing arm is fixed. A valve body that can rotate between the closed position that closes the steam flow path portion and the accommodation position that is accommodated in the valve accommodating portion, and the steam flow path portion when the valve body is in the accommodation position. On the back surface side of the valve body, which is on the opposite side of the valve body, an intrusion suppressing portion for suppressing the intrusion of the steam from the steam flow path portion is provided.

With such a configuration, when the valve body is in the accommodation position, the intrusion suppressing portion can suppress the invasion of steam to the valve back surface side of the valve body. As a result, it is possible to suppress an increase in the pressure on the valve back surface side of the valve body. Therefore, it is possible to prevent the valve body from moving toward the closed position when it is not needed.

According to the second aspect of the present invention, the steam turbine has a flow path forming portion forming a steam flow path portion through which steam flows, a casing having a valve accommodating portion recessed from the steam flow path portion, and the valve accommodating portion. A rotation shaft that intersects the steam flow direction in the steam flow path portion and a first end portion are rotatably supported around the rotation shaft, and the first end portion to the second end portion are provided. A swing arm extending toward, a drive unit that rotates the swing arm around the rotation axis, and a second end portion of the swing arm, which are fixed to the swing arm and rotate together with the swing arm to obtain the above-mentioned. A valve body that can rotate between the closed position that closes the steam flow path portion and the accommodation position that is accommodated in the valve accommodating portion, and the steam flow path portion when the valve body is in the accommodation position. Is provided with an intrusion suppressing portion for suppressing the intrusion of steam from the steam flow path portion on the back surface side of the valve body on the opposite side, and the intrusion suppressing portion is the first end portion of the swing arm. It may be provided with a first suppression unit that suppresses the intrusion of steam between the and the casing.
By arranging the first restraining portion on the downstream side in the flow direction of the valve accommodating portion where steam easily flows from the steam flow path portion in this way, the steam flowing through the steam flow path portion is transferred to the first end portion of the swing arm and the casing. It is possible to efficiently suppress the invasion into the valve back surface side of the valve body through the space between the valve body and the valve body.

According to the third aspect of the present invention, the intrusion suppressing portion according to the first or second aspect may include a fixing portion fixed to the swing arm.
With this configuration, by fixing the fixed portion to the swing arm, the intrusion suppression portion can be easily attached to the swing arm.

According to the fourth aspect of the present invention, the swing arm according to the third aspect includes a plurality of supported portions provided at intervals in the axial direction of the rotating shaft and supported by the rotating shaft. May be good. The intrusion suppressing portion extends from the first suppressing portion toward the upstream side in the flow direction of the steam flowing through the steam flow path portion, and the intrusion of steam between the supported portions adjacent to each other in the axial direction. It may be provided with the second suppression part which suppresses.
With this configuration, even when the supported portions of the swing arm are separated, the second suppressing portion can suppress the intrusion of steam between these supported portions.

According to the fifth aspect of the present invention, the fixing portion in the fourth aspect may be fixed to the swing arm between the supported portions adjacent in the axial direction.
By doing so, it is possible to prevent the fixed portion from becoming an obstacle and hindering the movement of the swing arm.

According to the sixth aspect of the present invention, the valve accommodating portion according to any one of the first to fifth aspects is the region on the back surface side of the valve body and the flow of the steam flowing through the steam flow path portion. A communication portion that communicates with the steam flow path portion that is upstream of the valve body in the direction and has a lower pressure than the region on the back surface side of the valve body may be further provided.
With this configuration, when steam invades the region on the valve back surface side of the valve body from the steam flow path portion, the invading steam is discharged to the steam flow path portion through the communication portion. As a result, it is possible to prevent the pressure in the region on the back surface side of the valve body from increasing due to the steam that has entered the back surface side of the valve body.

According to the seventh aspect of the present invention, the flow path forming portion according to any one of the first to sixth aspects is connected to the downstream side in the distribution direction of the steam pipe through which the steam supplied from the outside flows. The intrusion suppression portion may be arranged on the downstream side of the elbow portion where the steam pipe is curved and outside the bending direction of the elbow portion.
With this configuration, on the downstream side of the elbow portion where the steam pipe is curved, the intrusion suppression unit prevents steam biased to the outside in the bending direction of the elbow portion from entering the valve back side of the valve body due to centrifugal force. Can be effectively suppressed.

According to the eighth aspect of the present invention, the steam turbine includes a steam stop valve according to any one of the first to seventh aspects.

With such a configuration, it is possible to provide a steam turbine provided with a steam stop valve that can suppress the valve body from moving toward the closed position when it is not needed.

According to the steam stop valve and the steam turbine, it is possible to prevent the valve body from moving toward the closed position when it is not needed.

It is sectional drawing which shows an example of the steam supply path formed by using the steam stop valve and the steam turbine of the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the said steam stop valve. It is a perspective view which shows the swing arm provided in the steam stop valve, the valve body, and the intrusion suppressing member. It is a perspective view which saw the swing arm, the valve body, and the intrusion suppressing member provided in the steam stop valve from the angle different from FIG. It is a schematic diagram which shows the schematic structure of the drive part of the said steam stop valve. It is sectional drawing which shows the state which arranged the valve body of the said steam stop valve in a closed position. It is a perspective view which shows the steam invasion suppressing member in the modification of the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the steam stop valve in the 2nd Embodiment of this invention.

Next, the steam stop valve and the steam turbine according to the embodiment of the present invention will be described with reference to the drawings.
(First Embodiment)
FIG. 1 is a cross-sectional view showing an example of a steam supply path formed by using the steam stop valve and the steam turbine according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view showing the configuration of the steam stop valve.
As shown in FIG. 1, the steam stop valve 10 of the first embodiment is provided in the steam supply path 1 for supplying steam (main steam) to the steam turbine 200 from an external steam supply source. The steam supply path 1 is configured by connecting a plurality of steam pipes 100. The steam stop valve 10 is arranged between the steam pipe 100A on the upstream side in the steam flow direction (hereinafter, simply referred to as the flow direction Df) in the steam supply path 1 and the steam pipe 100B on the downstream side in the flow direction Df. ing. In this embodiment, the steam pipe 100A on the upstream side is provided with an elbow portion 101 that curves the steam flow path.

As shown in FIG. 2, the steam stop valve 10 includes a casing 11, a swing arm 20, a drive unit 40 (see FIG. 5), a valve body 30, and a steam intrusion suppression member (intrusion suppression unit) 50. I have.

The casing 11 has a flow path forming portion 12 and a valve accommodating portion 13.
The flow path forming portion 12 has a cylindrical shape extending so as to connect the steam pipe 100A on the upstream side and the steam pipe 100B on the downstream side. The flow path forming portion 12 forms a steam flow path portion Sf through which steam flows, inside the flow path forming portion 12.

The valve accommodating portion 13 is formed in an intermediate portion in the extending direction of the flow path forming portion 12. The valve accommodating portion 13 is recessed from the steam flow path portion Sf to the outside of the flow path forming portion 12 in the radial direction with respect to the flow path forming portion 12. The valve accommodating portion 13 is formed in a cylindrical shape extending radially outward from the flow path forming portion 12, and the radial outer end portion 13a is closed by the lid body 14.
The flow path forming portion 12 of the steam stop valve 10 in this embodiment is connected to the downstream side of the steam pipe 100A in the flow direction Df. Further, the valve accommodating portion 13 of the steam stop valve 10 in this embodiment is arranged on the downstream side of the flow direction Df of the elbow portion 101 in the cross section shown in FIG. The elbow portion 101 is arranged on the side far from the center of the curved radius of curvature.

The rotary shaft 15 is provided in the valve accommodating portion 13. The rotation axis 15 extends in a direction intersecting the steam flow direction Df in the steam flow path portion Sf (direction orthogonal to the paper surface in FIG. 2). The end portion of the rotating shaft 15 penetrates the valve accommodating portion 13 and projects to the outside of the casing 11.

The valve accommodating portion 13 includes a shaft accommodating recess 16. The shaft accommodating recess 16 is formed on the inner wall surface 13w of the inner wall surface of the valve accommodating portion 13 on the downstream side of the steam flow path portion Sf in the steam flow direction Df. The shaft accommodating recess 16 is recessed on the downstream side of the steam flow direction Df with respect to the inner wall surface 13w. The rotating shaft 15 is arranged inside the shaft accommodating recess 16 at intervals in the radial direction of the rotating shaft 15. That is, the outer peripheral surface 15f of the rotating shaft 15 and the inner peripheral surface 16f of the shaft accommodating recess 16 are arranged at intervals in the radial direction of the rotating shaft 15.

The first end portion 20a of the swing arm 20 is supported by the rotation shaft 15. The swing arm 20 has an arm shape extending from the first end portion 20a toward the second end portion 20b. The second end portion 20b of the swing arm 20 is arranged on the upstream side of the distribution direction Df with respect to the first end portion 20a in a state where the valve body 30 is housed in the valve accommodating portion 13.

FIG. 3 is a perspective view showing a swing arm, a valve body, and an intrusion suppressing member provided in the steam stop valve. FIG. 4 is a perspective view of the swing arm, the valve body, and the intrusion suppressing member provided in the steam stop valve as viewed from an angle different from that in FIG.
As shown in FIGS. 3 and 4, the swing arm 20 has a plurality of, more specifically, a pair of supported portions, which are spaced apart from each other in the first end portion 20a in the direction of the central axis C of the rotating shaft 15. Has 21. Each supported portion 21 extends in a direction away from the second end portion 20b. Each supported portion 21 has a shaft insertion hole 21h through which the rotating shaft 15 is inserted. The swing arm 20 is formed with a recess 24 recessed between the pair of supported portions 21 from the first end portion 20a toward the second end portion 20b. The supported portion 21 is fixed by inserting the rotating shaft 15 into the shaft insertion hole 21h. That is, the supported portion 21 is supported by the rotating shaft 15. As a result, the supported portion 21 rotates around the rotation shaft 15 as the rotation shaft 15 rotates.

A boss 20c is formed on the second end 20b of the swing arm 20. The boss 20c has a columnar shape extending outward in the radial direction of the steam flow path portion Sf. In the boss 20c, a flat surface portion 20d is formed at the outer end portion of the boss 20c in the radial direction of the steam flow path portion Sf. As shown in FIG. 2, the flat surface portion 20d of the swing arm 20 abuts on the protrusion 14t provided on the lid 14 when it rotates around the rotation axis 15. As a result, the rotation angle of the swing arm 20 is regulated.

FIG. 5 is a schematic diagram showing a schematic configuration of the drive unit of the steam stop valve.
The drive unit 40 rotates the swing arm 20 around the rotation shaft 15.
As shown in FIG. 5, the drive unit 40 is provided outside the casing 11. The drive unit 40 mainly includes a lever 41, a rod 42, a hydraulic cylinder 43, an urging spring 44, and a disc spring 45.

The lever 41 is provided at the end portion 15e of the rotating shaft 15 projecting to the outside of the casing 11. The lever 41 extends radially outward from the rotating shaft 15.
The rod 42 is rotatably connected to the radial outer tip of the lever 41 via a pin 46 or the like extending in the same direction as the rotation shaft 15.

The hydraulic cylinder 43 can press the piston 43p provided on the rod 42 by the hydraulic force F1 supplied from the outside. The hydraulic cylinder 43 rotates the rotating shaft 15 via the lever 41 by infesting the rod 42. For example, by displacing the rod 42 in the protruding direction by the hydraulic cylinder 43, the valve body 30 described in detail later can be displaced in the opening direction (the direction of moving from the closed position Pc to the accommodating position Ps).

The urging spring 44 exerts an urging force F2 that presses the plate 44p provided on the rod 42 in a direction opposite to the pressing direction by the hydraulic cylinder 43. The disc spring 45 exerts an urging force F3 that urges the rotating shaft 15 in the closing direction of the valve body 30 via the lever 41. The urging spring 44 and the disc spring 45 attach the rotating shaft 15 in the closing direction of the valve body 30 (the direction of moving from the accommodating position Ps to the closing position Pc) by pressing the rod 42 with the urging forces F2 and F3. Momentum.

As shown in FIGS. 3 and 4, the valve body 30 is formed in a disk shape including a valve surface 30a curved in a concave shape and a valve back surface 30b curved in a convex shape. The valve back surface 30b of the valve body 30 faces the side opposite to the steam flow path portion Sf when it is in the accommodation position Ps. The valve back surface 30b is fixed to a boss 20c provided at the second end 20b of the swing arm 20. The valve surface 30a faces the steam flow path portion Sf side when it is in the accommodation position Ps. In other words, the spreading direction of the valve body 30 coincides with the steam flow direction Df when it is in the accommodation position Ps.

FIG. 6 is a cross-sectional view showing a state in which the valve body of the steam stop valve is arranged at the closed position.
As shown in FIGS. 2 and 6, the valve body 30 rotates together with the swing arm 20 to rotate between the closed position Pc and the accommodating position Ps. The valve body 30 closes the steam flow path portion Sf of the casing 11 at the closing position Pc. The casing 11 is provided with a seal member 18 to which the outer peripheral edge portion of the valve body 30 abuts when the valve body 30 is located at the closed position Pc. As shown in FIG. 2, at the accommodation position Ps, the valve body 30 is accommodated in the valve accommodating portion 13. At the accommodating position Ps, the valve body 30 directs the valve surface 30a on the first surface side toward the steam flow path portion Sf side in the valve accommodating portion 13.

As shown in FIGS. 2 to 4, when the valve body 30 is in the accommodation position Ps, the steam intrusion suppressing member 50 is placed on the valve back surface 30b side on the side opposite to the valve surface 30a side (second surface side). It suppresses the invasion of steam flowing through the steam flow path portion Sf. The steam intrusion suppressing member 50 is arranged in the valve accommodating portion 13 on the downstream side of the steam flow direction Df, more specifically, on the downstream side of the valve body 30.

The steam intrusion suppressing member 50 includes a first suppressing portion 53, a second suppressing portion 52, and a fixing portion 51.
The first suppressing portion 53 suppresses the intrusion of steam between the first end portion 20a of the swing arm 20 and the casing 11. The first restraining portion 53 is a shaft accommodating recess formed in the casing 11 from the outer peripheral surface 21f of the supported portion 21 located at the first end portion 20a of the swing arm 20 when viewed from the central axis C direction of the rotating shaft 15. It extends toward the inner peripheral surface 16f of 16. The first restraining portion 53 is formed so as to cross between one inner surface (not shown) and the other inner surface (not shown) of the valve accommodating portion 13 in the extending direction of the rotation shaft 15. ..

The second suppressing portion 52 is formed so as to extend from the first suppressing portion 53 toward the upstream side of the steam flow direction Df. The second suppressing portion 52 suppresses the intrusion of steam between the supported portions 21 adjacent to each other in the extending direction of the rotating shaft 15. The lower surface of the second restraining portion 52 in this embodiment illustrates the case where the lower surface of the second suppressing portion 52 is arranged flush with respect to the lower surfaces of the two supported portions 21. Further, the second restraining portion 52 exemplifies a case where the second suppressing portion 52 is formed in a plate shape so as to close between two pairs of supported portions 21.

The fixing portion 51 is fixed to the swing arm 20. The fixing portion 51 in this embodiment has a plate shape and is fixed to the inner surface of the recess 24 between the supported portions 21 of the swing arm 20 by a screw 54 or the like. When the valve body 30 is in the accommodation position Ps, the fixing portion 51 in this embodiment is located along the inner surface of the recess 24 from the end portion of the second suppressing portion 52 which is upstream in the steam flow direction Df. (Ii) It extends in a direction intersecting the restraining portion 52.

As shown in FIGS. 2 and 6, when the swing arm 20 rotates around the rotation shaft 15, the steam intrusion suppressing member 50 rotates integrally with the swing arm 20. The steam intrusion suppressing member 50 rotates integrally with the swing arm 20 so that the valve body 30 does not interfere with the inner peripheral surface 16f of the shaft accommodating recess 16 from the accommodating position Ps to the closed position Pc. ing.

As shown in FIG. 1, the steam intrusion suppressing member 50 is arranged in the valve accommodating portion 13 located on the downstream side of the elbow portion 101 and outside the bending direction of the elbow portion 101. Further, the steam intrusion suppressing member 50 is arranged in the valve accommodating portion 13 on the downstream side in the flow direction Df of the steam flowing through the steam flow path portion Sf.

As shown in FIG. 2, the steam stop valve 10 is located at the accommodation position Ps in which the valve body 30 is accommodated in the valve accommodating portion 13 in normal times. The drive unit 40 presses the rod 42 by the hydraulic force F1 of the hydraulic cylinder 43, and rotates the rotary shaft 15 in the opening direction of the valve body 30. As a result, the position of the valve body 30 is maintained at the accommodation position Ps.
When it becomes necessary to stop the steam supply to the steam turbine 200 side, the drive unit 40 stops pressing the rod 42 by the hydraulic force F1 of the hydraulic cylinder 43. The rotary shaft 15 urges the valve body 30 in the closing direction by the urging forces F2 and F3 of the urging spring 44 and the disc spring 45. Therefore, as shown in FIG. 6, the swing arm 20 rotates integrally with the rotating shaft 15, and the valve body 30 moves from the accommodating position Ps to the closed position Pc. As a result, the flow path forming portion 12 of the casing 11 is blocked by the valve body 30, and the steam supply to the steam turbine 200 side is cut off.

Here, the steam pipe 100A on the upstream side of the steam stop valve 10 has an elbow portion 101 that curves the steam flow path. As described above, the steam flow path is curved at the elbow portion 101, so that a centrifugal force acts on the steam flowing in the steam pipe 100A. Due to the action of this centrifugal force, the flow of steam flowing into the steam flow path portion Sf is biased to the outside of the elbow portion 101 in the bending direction, that is, to the valve accommodating portion 13 side on the downstream side of the elbow portion 101. Then, a part of the steam flowing through the steam flow path portion Sf toward the gap between the first end portion 20a of the swing arm 20 located on the downstream side of the steam flow direction Df and the shaft accommodating recess 16 in the valve accommodating portion 13. Attempts to enter the valve accommodating portion 13. However, since the steam intrusion suppressing member 50 is provided in the gap between the first end portion 20a of the swing arm 20 and the shaft accommodating recess 16, steam is generated in the gap between the first end portion 20a and the shaft accommodating recess 16. It is possible to suppress entry. As a result, it is possible to prevent steam from entering the region s on the valve back surface 30b side of the valve body 30 through the gap between the first end portion 20a of the swing arm 20 and the shaft accommodating recess 16. Therefore, it is possible to suppress an increase in the pressure in the region Sb on the valve back surface 30b side of the valve body 30 in the valve accommodating portion 13.

Therefore, according to the first embodiment described above, when the valve body 30 is in the accommodation position Ps, the steam intrusion suppressing member 50 suppresses the invasion of steam into the region Sb on the valve back surface 30b side of the valve body 30. can. As a result, it is possible to suppress an increase in pressure in the region Sb on the valve back surface 30b side of the valve body 30. Therefore, when the valve body 30 is in the accommodation position Ps, it is possible to prevent the valve body 30 from moving from the accommodation position Ps when it is unnecessary. Further, by moving the valve body 30 from the accommodation position Ps when it is unnecessary, it is possible to prevent the rotary shaft 15 and the bearings supporting the rotary shaft 15 from being worn.

Further, the steam intrusion suppressing member 50 is provided so as to suppress the intrusion of steam between the first end portion 20a of the swing arm 20 and the casing 11. As a result, a part of the steam flowing through the steam flow path portion Sf is prevented from entering the valve back surface 30b side of the valve body 30 through between the first end portion 20a of the swing arm 20 and the casing 11. can.

Further, the steam intrusion suppressing member 50 includes a fixing portion 51 fixed to the swing arm 20. Therefore, the steam intrusion suppressing member 50 can be easily attached to the swing arm 20 by fixing the fixing portion 51 to the swing arm 20. In particular, by attaching the swing arm 20 to the fixing portion 51 with a screw 54 or the like, it is possible to additionally attach the steam intrusion suppressing member 50 to the existing steam stop valve 10.

Further, by providing the steam intrusion suppressing member 50 on the downstream side of the flow direction Df of the valve accommodating portion 13 where steam easily flows from the steam flow path portion Sf, the invasion of steam to the valve back surface 30b side of the valve body 30 is efficiently suppressed. be able to.

Further, the flow path forming portion 12 of the steam stop valve 10 is connected to the downstream side of the flow direction Df of the steam pipe 100A through which steam supplied from an external steam supply source flows. Further, on the downstream side of the elbow portion 101 in which the steam pipe 100A is curved, the valve accommodating portion 13 is arranged outside the bending direction of the elbow portion 101. In this case, the steam is biased to the outside in the bending direction of the elbow portion 101 due to the centrifugal force, but it is possible to effectively suppress the steam from entering the valve back surface 30b side of the valve body 30 by the steam intrusion suppressing member 50.

(Modified example of the first embodiment)
FIG. 7 is a perspective view showing a steam intrusion suppressing member in a modified example of the first embodiment of the present invention.
In the first embodiment, the steam intrusion suppressing member 50 is provided with the first suppressing portion 53 and the second suppressing portion 52 on the arm surface 20f side, which is the side where the valve body 30 is arranged in the swing arm 20. It is not limited to this configuration.
For example, like the steam intrusion suppression member (intrusion suppression unit) 50B shown in FIG. 7, the second suppression unit 52B and the second suppression unit 52B and the second suppression unit 52B are on the arm back surface 20g side opposite to the side where the valve body 30 is arranged in the swing arm 20. (1) The suppression unit 53B may be provided.

Further, the steam intrusion suppressing members 50 and 50B are not limited to the configuration in which the steam intrusion suppressing members 50 and 50B are mounted on the swing arm 20 by a screw 54 or the like. For example, the steam intrusion suppressing members 50 and 50B may be fixed to the swing arm 20 by welding, adhesion, or the like. Further, the steam intrusion suppressing members 50 and 50B and the swing arm 20 may be integrally molded in advance.

(Second embodiment)
Next, a second embodiment of the steam stop valve and the steam turbine according to the present invention will be described. In the second embodiment described below, only the configuration including the communication unit 70 is different from that of the first embodiment. Therefore, the same parts as those of the first embodiment are designated by the same reference numerals, and duplicate description is omitted. ..

FIG. 8 is a cross-sectional view showing the configuration of the steam stop valve according to the second embodiment of the present invention.
As shown in FIG. 8, the steam stop valve 10C in this embodiment includes a casing 11C, a swing arm 20, a drive unit 40, a valve body 30, and a steam intrusion suppressing member 50.

The casing 11C has a flow path forming portion 12, a valve accommodating portion 13, and a communication portion 70. The communication portion 70 includes a communication pipe 71 that connects the valve accommodating portion 13 and the flow path forming portion 12. In the communication pipe 71, one end 71a communicates with the valve accommodating portion 13, more specifically, the region Sb on the valve back surface 30b side, and the other end 71b is inside the flow path forming portion 12, more specifically. Is in communication with the steam flow path portion Sf on the upstream side of the valve body 30 in the steam flow direction Df. As a result, in the communication portion 70, the region Sb on the valve back surface 30b side of the valve body 30 and the steam flow path portion Sf in the flow path forming portion 12 are communicated with each other in the valve accommodating portion 13. Although the case where the end portion 71b of the communication pipe 71 constituting the communication portion 70 communicates with the steam flow path portion Sf on the upstream side of the valve body 30 in the steam flow direction Df has been described. In Sf, the end portion 71b may be communicated at a place where the pressure is lower than the region Sb in the valve accommodating portion 13.

In the steam stop valve 10C provided with such a communication portion 70, when steam invades the region Sb on the valve back surface 30b side of the valve body 30 from the steam flow path portion Sf and the pressure in the region Sb rises, the steam invades. The steam is discharged to the steam flow path portion Sf in the flow path forming portion 12 through the communication portion 70.

Therefore, according to the second embodiment described above, when the pressure of the region Sb on the valve back surface 30b side of the valve body 30 increases due to the communication portion 70, the flow path from the region Sb through the communication portion 70. Steam is discharged to the steam flow path portion Sf in the forming portion 12. As a result, it is possible to suppress an increase in the pressure in the region Sb on the valve back surface 30b side of the valve body 30. Therefore, when the valve body 30 is in the accommodation position Ps, it is possible to prevent the valve body 30 from moving from the accommodation position Ps when it is unnecessary.

Further, similarly to the steam stop valve 10 of the first embodiment described above, the steam intrusion suppressing member 50 suppresses the intrusion of steam into the region Sb on the valve back surface 30b side of the valve body 30. Therefore, it is possible to suppress an increase in the pressure in the region Sb. Therefore, when the valve body 30 is in the accommodation position Ps, it is possible to further suppress the valve body 30 from moving from the accommodation position Ps when it is unnecessary.

(Other variants)
The present invention is not limited to the above-described embodiment, and includes various modifications to the above-mentioned embodiment without departing from the spirit of the present invention. That is, the specific shape, configuration, and the like given in the embodiment are merely examples, and can be appropriately changed.
For example, configurations other than the steam stop valves 10, 10B and 10C, for example, the layout of the steam pipe 100, the position and shape of the elbow portion 101, and the like can be appropriately changed.
Further, the steam stop valves 10, 10B and 10C are not limited to the steam supply path 1 for supplying steam (main steam) to the steam turbine 200, and may be provided in steam pipes for other purposes.

1 Steam supply path 10, 10B, 10C Steam stop valve 11, 11C Casing 12 Flow path forming part 12a Opening part 13 Valve accommodating part 13w Inner wall surface 14 Lid 14t Protrusion 15 Rotating shaft 15e End part 15f Outer peripheral surface 16 Shaft accommodating recess 16f Inner peripheral surface 18 Seal member 20 Swing arm 20a First end 20b Second end 20c Boss 20d Flat surface 20f Arm surface 20g Arm back surface 21 Supported part 21f Outer peripheral surface 21h Shaft insertion hole 24 Recess 30 Valve surface 30a Valve surface 30b Valve back surface 40 Drive unit 41 Lever 42 Rod 43 Hydraulic cylinder 43p Piston 44 Bounce spring 44p Plate 45 Countersunk spring 46 Pin 50, 50B Steam intrusion suppression member 51 Fixing part 52, 52B Second suppression part 53, 53B First suppression part 54 Screw 70 Communication part 71 Communication pipe 71a End 71b End 100, 100A, 100B Steam pipe 101 Elbow 200 Steam turbine C Central axis Df Flow direction F1 Force F2, F3 Basis force Pc Blocking position Ps Containment position Sb Area Sf Steam flow Road part

Claims (8)

A casing having a flow path forming portion forming a steam flow path portion through which steam flows, and a valve accommodating portion recessed from the steam flow path portion.
A rotation shaft provided in the valve accommodating portion and intersecting the flow direction of the steam in the steam flow path portion,
A swing arm whose first end is rotatably supported around the axis of rotation and extends from the first end toward the second end.
A drive unit that rotates the swing arm around the axis of rotation,
By being fixed to the second end of the swing arm and rotating together with the swing arm, it is placed between the closed position that closes the steam flow path portion and the accommodation position that is accommodated in the valve accommodating portion. With a rotatable valve body,
When the valve body is in the accommodation position, the valve body is arranged on the downstream side of the valve body in the flow direction of the steam in the steam flow path portion and is on the opposite side to the steam flow path portion. An intrusion suppression unit that suppresses the intrusion of the steam from the steam flow path portion on the back surface side,
A steam stop valve equipped with. A casing having a flow path forming portion forming a steam flow path portion through which steam flows, and a valve accommodating portion recessed from the steam flow path portion.
A rotation shaft provided in the valve accommodating portion and intersecting the flow direction of the steam in the steam flow path portion,
A swing arm whose first end is rotatably supported around the axis of rotation and extends from the first end toward the second end.
A drive unit that rotates the swing arm around the axis of rotation,
By being fixed to the second end of the swing arm and rotating together with the swing arm, it is placed between the closed position that closes the steam flow path portion and the accommodation position that is accommodated in the valve accommodating portion. With a rotatable valve body,
When the valve body is in the accommodation position, an intrusion suppression unit that suppresses the invasion of the steam from the steam flow path portion to the back surface side of the valve body that is opposite to the steam flow path portion.
Equipped with
The intrusion suppressing portion is a steam stop valve including a first suppressing portion that suppresses the intrusion of steam between the first end portion of the swing arm and the casing. The intrusion suppression unit is
A fixed portion fixed to the swing arm,
2. The steam stop valve according to claim 2. The swing arm
A plurality of supported portions provided at intervals in the axial direction of the rotating shaft and supported by the rotating shaft are provided.
The intrusion suppression unit is
A second suppression that extends from the first suppression portion toward the upstream side of the steam flowing through the steam flow path portion in the flow direction and suppresses the intrusion of steam between the supported portions adjacent to each other in the axial direction. The steam stop valve according to claim 3, further comprising a unit. The fixed part is
The steam stop valve according to claim 4, which is fixed to the swing arm between the supported portions adjacent to each other in the axial direction. The valve accommodating part
The steam flow path having a lower pressure than the region on the back surface side of the valve body and the region on the back surface side of the valve body in the flow direction of the steam flowing through the steam flow path portion on the upstream side of the valve body. The steam stop valve according to any one of claims 1 to 5, further comprising a communication unit that communicates with the unit. The flow path forming portion is connected to the downstream side in the distribution direction of the steam pipe through which steam supplied from the outside flows.
The steam stop valve according to any one of claims 1 to 6, wherein the intrusion suppressing portion is arranged on the downstream side of the elbow portion where the steam pipe is curved and outside the bending direction of the elbow portion. A steam turbine comprising the steam stop valve according to any one of claims 1 to 7.

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