JP2008175267A - Steam valve apparatus and power generation plant having it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the generation of noise or vibration from the minute opening to the vicinity of the middle opening, and enable the improvement in the efficiency of a steam turbine by reducing the pressure drop at the full opening or its vicinity. <P>SOLUTION: The steam governing valve 42 includes a valve chest 57 formed with a valve body 56, a valve seat 58 which has a spherically curved surface and which is provided for the valve main body at the position facing the valve chest, and a valve body 60 which is driven by a valve rod 59 and which has a spherically curved surface, and which is held in the valve chest. The opening of the steam governing valve is defined by the contact and separation of the spherically curved surfaces of the valve seat and the valve body. A recessed part 62 having an edge 61 at the rim is provided on the bottom side of the valve body. A chamber member 63 located on the outside of the valve body and a flow guide 64 arranged in the recessed part of the valve body is provided for the valve body 56. The steam passage 65 at the full opening or its vicinity is formed by the chamber member, the valve body, the flow guide, the inner peripheral surface 56A of the valve main body, and the valve seat. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a steam valve device for a steam turbine applied to a power generation facility such as a thermal power plant or a nuclear power plant, and a power generation facility including the steam valve device.

  In general, a steam turbine applied to a power generation facility such as a thermal power plant or a nuclear power plant has a large number of steams in order to control the flow rate of steam according to a load change or shut off the supply of steam in the event of a sudden accident. A valve device is provided.

  FIG. 13 is an explanatory diagram of a conventional steam valve device used in a steam turbine. FIG. 13 shows a main steam stop valve 10 that instantaneously stops steam flowing into the steam turbine in an emergency of the steam turbine, and a steam control valve 20 for controlling the steam flow rate.

  The valve body 21 of the steam control valve 20 has a side portion connected to the main steam stop valve 10 and is connected to the valve body 21, and has an upper lid 22 at the upper end portion of the valve body 21. A valve seat 23 having a raised shape is provided, and a valve rod 25 coupled to a valve body 24 that contacts the valve seat 23 passes through the upper lid 22 and is connected to an oil cylinder 27.

  A steam flow from a boiler or the like (not shown) flows into the main steam stop valve 10 as indicated by arrow I and flows out of the steam control valve 20 as indicated by arrow O. When oil pressure is applied to the oil cylinder 27 of the steam control valve 20, the valve body 24 moves up and down via the valve rod 25, and the steam control valve 20 opens and closes. The steam flow is controlled by this opening and closing operation, not shown. Steam flows to the steam turbine.

  A piston 26 and a closing spring 29 are assembled to the oil cylinder 27 of the steam control valve 20, and a supply / discharge oil port 28 is installed at the lower part of the piston 26. Although hydraulic equipment such as a servo valve and a dump valve is connected to the supply / discharge oil port 28, the illustration thereof is omitted in FIG.

  On the other hand, the main steam stop valve 10 is also configured in the same manner as the steam control valve 20, and has an upper lid 12 at the upper end portion of the valve main body 21, and a valve seat 14 having a raised shape at the inner portion of the valve main body 11. A valve body 15 that contacts the valve seat 14 is connected to an oil cylinder 17 via a valve rod 16. When oil pressure is applied to the oil cylinder 17, the valve body 15 moves up and down via the valve rod 16, and the main steam stop valve 10 opens and closes. Steam is supplied and shut off by this opening and closing operation. In addition, the code | symbol 13 in FIG. 13 shows a strainer.

  In general, in the steam valve device used in the steam turbine for power generation equipment, particularly the steam control valve 20, incompatible cases such as noise, vibration, erosion or material deterioration are known.

  Such a steam control valve 20 controls the steam flow rate by the throttle function between the valve body 24 and the valve seat 23 by moving the valve body 24 in the valve chamber provided with the valve body 24 and the valve seat 23. It is configured as follows. The above-described noise and vibration are considered to be induced by a turbulent flow or an unstable flow around the valve body 24 (see, for example, Patent Document 1).

  Recently, an improved technique has been proposed in which further improvements have been made in accordance with an increase in steam conditions (supercritical pressure plant) of a power generation facility and an increase in the unit capacity of a steam turbine (see, for example, Patent Document 2).

  As shown in FIGS. 14 and 15, the steam control valve 20 in Patent Documents 1 and 2 described above is formed in a spherical curved surface, and has a valve body 24 having a recessed portion 30 having an edge 31 on an edge, and the valve body. The valve seat 23 has a spherical curved surface so as to gradually widen toward the downstream side from the position where the valve 24 abuts. The valve body 24 and the spherical curved surface of the valve seat 23 are configured to abut each other. ing.

Therefore, in this steam control valve 20, since the recessed part 30 provided with the edge 31 is provided on the bottom side of the valve body 24, the steam along the valve body 24 in the vicinity of the intermediate opening from the minute opening. Is peeled off at the edge 31 of the valve body 24 and becomes a stable flow along the valve seat 23, thereby preventing the generation of noise and vibration.
JP-A-56-109955 Japanese Unexamined Patent Publication No. 2006-63957

  However, the valve body 24 of the conventional steam control valve 20 has a concave portion 30 with an edge 31 on the edge, and is an original function in the region near the intermediate opening from the beginning of opening of the valve body 24. Although effective in preventing noise and vibration, in a high valve opening state such as when the valve is fully opened, a dead space is directly under the valve body 24, and a vortex is formed in this dead space as shown by an arrow in FIG. Will occur and pressure loss will occur.

  By the way, in recent steam turbines, performance improvement (efficiency improvement) is strongly demanded as a market demand by power generation business owners. As a breakdown of the efficiency of the steam turbine, the internal efficiency of the steam turbine itself is important, but the above-described pressure loss in the steam control valve 20 installed at the inlet of the steam turbine is also extremely important. In other words, the pressure loss that occurs in the steam control valve 20 or the like means that the steam pressure at the inlet of the steam turbine before the thermodynamically effective work is reduced, resulting in a large influence on the efficiency of the steam turbine ( Efficiency reduction). For this reason, in the steam valve device such as the steam control valve 20, it has been a long-standing concern how to reduce the pressure loss in the fully opened state.

  The object of the present invention has been made in consideration of the above-mentioned circumstances, and can prevent noise and vibration from the minute opening to the intermediate opening, and reduce the pressure loss at or near the fully opened opening. An object of the present invention is to provide a steam valve device capable of improving the efficiency of a steam turbine and a power generation facility including the same.

  In the present invention, a valve chamber is formed by a valve body, and the valve body is provided with a valve seat having a spherical curved surface at a position facing the valve chamber, and the valve chamber is driven by a valve rod and has a spherical curved surface. In the steam valve device in which the valve opening is set by contacting and separating the valve seat and the spherical curved surface of the valve body, an edge is provided on the edge side on the bottom side of the valve body. A recessed portion is provided, and on the valve body side, a chamber member positioned outside the valve body and a flow guide disposed in the recessed portion of the valve body are provided. The body, the flow guide, the inner surface of the valve main body, and the valve seat form a steam passage portion at or near the fully open position.

  According to the present invention, since the concave portion provided with the edge on the edge side is provided on the bottom side of the valve body, the flow of steam along the valve body near the intermediate opening from the minute opening degree Since it is peeled off at the edge and becomes a stable flow along the valve seat, generation of noise and vibration can be prevented. In addition, since the chamber member is provided outside the valve body, and the flow guide is provided in the recessed portion of the valve body, the change in the flow passage area near the valve body is small in the full opening degree or in the steam passage portion in the vicinity thereof. Become. For this reason, the flow of the steam flowing through the steam passage portion does not cause a vortex in the vicinity of the recessed portion of the valve body, and hence pressure loss is suppressed, so that the efficiency of the steam turbine can be improved.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[A] First Embodiment FIG. 1 is a cross-sectional view showing a fully closed state of a steam control valve, which is a first embodiment of a steam valve device according to the present invention. FIG. 2 is a cross-sectional view showing a minute opening state of the steam control valve of FIG. FIG. 3 is a longitudinal sectional view showing an intermediate opening state of the steam control valve 2 of FIG. FIG. 4 is a longitudinal sectional view showing a fully opened state of the steam control valve of FIG. FIG. 9 is a system diagram showing a power generation facility equipped with the steam control valve shown in FIGS.

  In the power generation equipment 55 shown in FIG. 9, the steam from the boiler 40 passes through the main steam stop valve 41 and the steam control valve 42, expands in the high-pressure turbine 50 and works, and then again passes through the check valve 47. Heated by the reheater of the boiler 40, sequentially flows into the intermediate pressure turbine 51 and the low pressure turbine 52 via the reheat steam stop valve 43 and the intercept valve 44, and expands to work. The steam is worked by the low-pressure turbine 52 and then returned to water by the condenser 53, boosted by the feed water pump 54, supplied to the boiler 40 and circulated again.

  In addition, in order to increase the operation efficiency of the power generation equipment 55, depending on the power generation equipment 55, a high pressure turbine bypass pipe 48 and a low pressure turbine bypass pipe 49 are installed, and the boiler 40 is installed regardless of the operating state of the turbines 50, 51, 52. It is possible to drive alone. The high-pressure turbine bypass pipe 48 branches from the outlet side of the boiler 40 and is connected to the inlet side of the reheater of the boiler 40 and includes a high-pressure turbine bypass valve 45. The low-pressure turbine bypass pipe 49 is branched from the outlet side of the reheater of the boiler 40 and connected to the inlet side of the condenser 53, and includes a low-pressure turbine bypass valve 46.

  As shown in FIGS. 1 and 5, the steam control valve 42 as a steam valve device provided in the above-described power generation facility 55 has a valve chamber 57 formed by a valve body 56, and the valve body 56 includes a valve chamber 57. A valve seat 58 having a spherical curved surface is provided at a position facing 57, and a valve body 60 driven by a valve rod 59 and having a spherical curved surface is accommodated in the valve chamber 57, and the valve seat 58 and the valve body 60 are The valve opening is set by the contact and separation of the spherical curved surface. A concave portion 62 having an edge 61 on the edge is provided on the bottom side of the valve body 60, and a valve member 56 is provided with a chamber member 63 positioned outside the valve body 60 via an upper lid 66, and a valve A flow guide 64 disposed in the recessed portion 62 of the body 60 is provided. The chamber member 63, the valve body 60, the flow guide 64, the inner peripheral surface 56 </ b> A of the valve body 56 and the valve seat 58 form a steam passage portion 65 at or near the fully open position.

  That is, the upper lid 66 is provided at the upper end of the valve body 56, and the valve seat 58 is provided inside the valve body 56. A valve rod 59 is coupled to the valve body 60 in contact with the valve seat 58, and the valve rod 59 passes through the upper lid 66 and is connected to an oil cylinder (not shown). When hydraulic pressure is applied to the oil cylinder, the valve body 60 moves up and down in FIGS. Since the penetrating portion of the valve stem 59 in the upper lid 66 is a sliding surface of the valve stem 59, a bush is assembled, but the illustration is omitted in the present embodiment.

  The valve body 60 is formed in a cylindrical shape having a top portion 67 and is provided with a recessed portion 62 on the inner side. The diameter of the edge 61 of the recessed portion 62 matches the inner diameter of the valve body 60. By providing a recessed portion 62 having an edge 61 on the edge on the bottom side of the valve body 60, as shown in FIGS. 2 and 3, in the vicinity of the intermediate opening from the minute opening of the steam control valve 42, Since the steam flow along the valve body 60 is separated by the edge 61 of the valve body 60 and becomes a stable flow along the valve seat 58, generation of noise and vibration is prevented. Since the steam flow at this time is a valve seat adhering flow along the valve seat 58 as described above, there is no flow along the outer surface 70 of the flow guide 64.

  A part of the upper lid 66 extends to the inside of the valve body 56 and is configured as a chamber member 63, and the valve body 60 is accommodated in the chamber member 63. Inside the valve body 60, a flow guide 64 having a central portion 85 protruding in a convex shape toward the valve seat 58 and having a tapered tip is disposed. The central portion 85 of the flow guide 64 protrudes in a convex shape and the tip is formed in a tapered shape, so that the flow passage area of the steam passage portion 65 at the fully open position or in the vicinity thereof is upstream of the valve seat 58. Smooth transition from the annular portion 65A to the circular portion 65B on the downstream side of the valve seat 58 facilitates the flow of steam at or near the fully open position shown in FIGS.

  The flow guide 64 is fixed to the chamber member 63 using a plurality of stepped screw pins 68, and is integrated with the chamber member 63. The valve body 60 is processed with a long hole 69 extending in the axial direction that is the moving direction of the valve body 60. By disposing the stepped screw pin 68 in the long hole 69, contact between the stepped screw pin 68 and the valve body 60 is avoided. Further, the valve body 60 is formed with a balance hole 60A for releasing the pressure inside the chamber member 63, and the vertical movement of the valve body 60 is ensured.

  As described above, the steam passage portion 65 at or near the fully open opening is formed by the chamber member 63, the valve body 60, the flow guide 64, the inner peripheral surface 56A of the valve body 56, and the valve seat 58. The flow passage area of the steam passage portion 65 is defined by the valve seat 58 from the upstream annular portion 65A defined by the inner peripheral surface 56A of the valve body 56 and the chamber member 63. It gradually decreases toward the circular portion 65B on the downstream side, and there is no extreme change until it finally reaches the opening area of the valve seat 58 (the area defined by the inner diameter of the valve seat 58). Configured to change. As a result, the steam flowing through the steam passage 65 at or near the full opening degree flows smoothly without generating a vortex in the vicinity of the lower part of the valve body 60 as shown by the arrow in FIG. It is suppressed.

  A typical change characteristic of the flow passage area of the steam passage portion 65 in the fully opened state is shown by a curve A in FIG. The flow passage area of the steam passage portion 65 gradually decreases from the inner peripheral surface 56A of the upstream valve body 56 toward the downstream valve seat 58, and the portion formed by the valve body 60 and the valve seat 58 is minimized. It is set so that it will become, and after that, it will increase slightly and will finally reach the area prescribed | regulated by the internal diameter of the valve seat 58. FIG. The reason why the portion formed by the valve body 60 and the valve seat 58 is minimized is that the steam control valve 42 controls the flow rate of steam at this portion.

  The change characteristic of the flow path area from the inlet (upstream end) to the outlet (downstream end) of the steam passage 65 is optimally designed so that the pressure loss is minimized, and the characteristic is the curve A described above. Or a straight line B connecting the entrance and exit, or a curved curve C or curve D. Further, the position where the minimum flow passage area is set is also optimally set so that the pressure loss is minimized.

  Here, using FIG. 8A and FIG. 8B, a method for obtaining the flow path area of the steam passage portion 65 in the fully opened state will be described.

  First, the flow path area of the inlet portion (upstream side) of the steam passage portion 65 is an area of an annular portion 65 </ b> A configured by the inner peripheral surface 56 </ b> A of the valve body 56 and the outer peripheral surface of the chamber member 63. Further, the flow path area of the outlet portion (downstream side) of the steam passage portion 65 is the area of the circular portion 65 </ b> B defined by the inner diameter of the valve seat 58.

Next, the flow path area on the way from the inlet part to the outlet part of the steam passage part 65 is obtained geometrically. When in the fully opened position, the chamber member 63, the valve body 60, the flow guide 64, the valve seat 58, and the inner peripheral surface 56A of the valve body 56 constitute the steam passage portion 65 in the fully opened position. In the steam passage portion 65, innumerable truncated cones 71A, 71B, 71C,... Are continuously imagined along the flow direction. The area (side area) of the side surface 74 excluding the areas of the upper bottom surface 73 and the lower bottom surface 72 of these truncated cones 71A, 71B, 71C... Is the flow path area at each truncated cone position of the steam passage portion 65. When the radius of the lower bottom surface 72 is R ₁ , the radius of the upper bottom surface 73 is R ₂ , and the height is h, the side areas of the truncated cones 71A, 71B, 71C.
[Equation 1]
Side area of the truncated cone = π x ((h ² + (R ₁ −R ₂ ) ² ) ^1/2 x (R ₁ + R ₂ )
It becomes.

Further, at the tip end portion of the flow guide 64 in the steam passage portion 65 in the fully opened opening state, a cone 75 is virtually assumed instead of the truncated cone. The area (side area) of the side surface of the cone 75 is the flow area at the position of the cone 75 of the steam passage portion 65. When the radius of the bottom surface of the cone 75 is R ₀ and the height is h ₀ , the side area of the cone 75 is obtained by the following equation.

[Equation 2]
Side area of cone = π x R ₀ x (h ₀ ² + R ₀ ² ) ^1/2
As described above, the flow passage area at each position of the steam passage portion 65 in the fully opened state is obtained, and the valve body is set so that the change characteristic of the flow passage area becomes the optimum characteristic as shown in FIG. While changing the dimensions and shapes of the inner peripheral surface 56A of 56, the chamber member 63, the valve body 60, the flow guide 64, and the valve seat 58, the shape of the steam passage portion 65 is determined. However, since the shape of the steam passage portion 65 cannot be determined if all of these dimensions are variables, the minimum standard dimensions and shapes are as follows from the viewpoint of reducing pressure loss and preventing noise and vibration. Are specifically defined.

  First, as shown in FIG. 5, the longitudinal cross-sectional shape of the outer surface 70 that forms the steam passage portion 65 of the flow guide 64 has an inverse curvature portion formed by a curve of a radius Rr having a center Or outside the flow guide 64. It has become. As a result, the flow of the steam along the outer surface 70 of the flow guide 64 at the full opening degree or in the vicinity thereof, and the flow of the steam along the outer surface 70 of the flow guide 64 easily becomes a flow parallel to the axis P direction of the valve seat 58. It flows to the downstream side of the valve seat 58 without colliding. Thereby, generation | occurrence | production of a vortex is suppressed under the flow guide 64, and pressure loss is reduced.

Further, the diameter Di of the edge 61 in the recessed portion 62 of the valve body 60 is set such that the seat diameter of the valve seat 58 that contacts the valve body 60 is Do,
[Equation 3]
Do> Di ≧ 0.9 Do
And the inner diameter Dth of the valve seat 58 is
[Equation 4]
Di> Dth ≧ 0.8 Do
Is set in the range. As a result, the steam flowing in the steam passage section 65 in the vicinity of the minute opening to the intermediate opening becomes a stable flow along the valve seat 58 (see arrows in FIGS. 2 and 3), and noise and vibration are generated. Is prevented.

Further, the radius of curvature R of the valve body 60 is set so that the seat diameter of the valve seat 58 contacting the valve body 60 is Do.
[Equation 5]
R = (0.52-0.6) Do
And the radius of curvature r of the valve seat 58 is
[Equation 6]
r ≧ 0.6 Do
Is set in the range. Also by this, the steam flowing in the steam passage portion 65 in the vicinity of the minute opening to the intermediate opening becomes a stable flow along the valve seat 58, and noise and vibration are prevented from being generated.

  5 and 6, the longitudinal cross-sectional shape of the inner surface 56A of the valve body 56 in the vicinity of the upstream side of the valve seat 58 is a curve 76 circumscribing the curvature radius r of the valve seat 58. (Fig. 6 (A)) or a straight line circumscribing the radius of curvature r of the valve seat 58 and having an arbitrary angle (preferably, an inverted triangular side 77 having an apex angle of approximately 90 degrees). A shape connected to the valve seat 58 is formed (FIG. 6B). As a result, no unnecessary space is formed on the inner surface 56A of the valve body 56, so that the generation of vortices in the vicinity of the upstream side of the valve seat 58 is suppressed.

  With the configuration as described above, the following effects (1) to (3) are achieved according to the present embodiment.

  (1) Since the recessed portion 62 having the edge 61 on the edge side is provided on the bottom side of the valve body 60, the steam along the valve body 60 is near the intermediate opening from the minute opening of the steam control valve 42. Since the flow is separated at the edge 61 of the valve body 60 and becomes a stable flow along the valve seat 58, generation of noise and vibration can be prevented.

  (2) Since the chamber member 63 is provided outside the valve body 60 and the flow guide 64 is provided in the recessed portion 62 of the valve body 60, the valve body 60 in the steam passage portion 56 at or near the full opening degree. The change in the channel area in the vicinity is reduced. For this reason, the flow of the steam flowing through the steam passage portion 56 at or near the full opening degree does not cause a vortex below the valve body 60, and therefore pressure loss is suppressed, thereby improving the efficiency of the steam turbine. Can be made.

  (3) For example, in a steam turbine in a combined cycle power generation facility, there are many cases where the steam control valve 42 is always operated in a fully open state. On the other hand, in the steam control valve 42 of the present embodiment, the efficiency of the steam turbine can be improved at or near the fully open position as described in (2) above. Therefore, the efficiency of the entire power generation facility can be improved by using the steam control valve 42 of the present embodiment in a highly efficient power generation facility such as a combined cycle.

[B] Second Embodiment In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description will be simplified or omitted.

The steam control valve of the second embodiment differs from the steam control valve 42 of the first embodiment in the value of the radius of curvature r of the valve seat 58 and the shape of the inlet structure of the valve seat 58. . That is, in the present embodiment, the curvature radius R of the valve body 60 is the same as in the first embodiment when the seat diameter of the valve seat 58 that contacts the valve body 60 is Do.
[Equation 7]
R = (0.52-0.6) Do
The radius of curvature r of the valve seat 58 is
[Equation 8]
r = (0.45-0.85) Do
Is set in the range. Furthermore, the shape of the inlet structure of the valve seat 58 which consists of the inlet_port | entrance of this valve seat 58 and the internal peripheral surface 56A in the surrounding valve main body 56 is formed in the bellmouth shape.

  Therefore, also in the present embodiment, the shape of the inlet structure of the valve seat 58 is formed in the bell mouth shape, so that the steam flowing from the periphery of the valve seat 58 into the valve seat 58 becomes a smooth flow and pressure. Since the loss is suppressed, the same effects as the effects (1) to (3) of the first embodiment are obtained.

[C] Third embodiment (FIG. 10)
FIG. 10 is a longitudinal sectional view showing a fully opened state of the steam control valve which is the third embodiment of the steam valve device according to the present invention. In the third embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description will be simplified or omitted.

  This embodiment is different from the first embodiment in the shape of the outer surface 78 that forms the steam passage portion 65 of the flow guide 64. That is, the longitudinal cross-sectional shape of the outer surface 78 that forms the steam passage portion 65 of the flow guide 64 in the present embodiment is formed as a straight line 79 that circumscribes the spherical curved surface at the end of the edge 61 of the valve body 60 at the fully opened position. ing.

  As a result, the flow of the steam along the outer surface 78 of the flow guide 64 at the full opening degree or in the vicinity thereof tends to be a flow parallel to the direction of the axis P of the valve seat 58. It flows to the downstream side of the valve seat 58 without colliding. Thereby, generation | occurrence | production of a vortex is suppressed under the flow guide 64, and pressure loss is reduced. Therefore, the present embodiment also provides the same effects as the effects (1) to (3) of the first embodiment.

[D] Fourth embodiment (FIG. 11)
FIG. 11: is a longitudinal cross-sectional view which shows the fully open opening state in the steam control valve which is 4th Embodiment of the steam valve apparatus which concerns on this invention. In the fourth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description will be simplified or omitted.

  The present embodiment is different from the first embodiment in that a flat portion 80 is provided at the forefront of the central portion 85 of the flow guide 64. That is, in the flow guide 64 in the present embodiment, the central portion 85 protrudes in a convex shape toward the downstream valve seat 58, the tip thereof is tapered, and the flat portion 80 is formed at the forefront. . The flat portion 80 is formed as a plane orthogonal to the axis of the flow guide 64, for example. In this case, the longitudinal cross-sectional shape of the outer surface forming the steam passage portion 65 of the flow guide 64 may be the outer surface 70 provided with the reverse curvature portion of the first embodiment, or the third It may be the outer surface 79 of the embodiment.

  Thus, even if the flat portion 80 is formed at the forefront of the convex central portion 85 of the flow guide 64, the flow guide 64 flows in the steam passage portion 65 at or near the full opening degree, and the outer surface 70 of the flow guide 64. Alternatively, the steam flow along 78 is likely to be parallel to the direction of the axis P of the valve seat 58, so that no vortex is generated below the flow guide 64 and pressure loss is reduced. Therefore, the present embodiment also provides the same effects as the effects (1) to (3) of the first embodiment.

[E] Fifth embodiment (FIG. 12)
FIG. 12 is a longitudinal sectional view showing a fully opened state of the steam control valve which is the fifth embodiment of the steam valve device according to the present invention. In the fifth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description will be simplified or omitted.

  This embodiment is different from the first embodiment in that a seat surface 81 is provided at an end of the valve stem 59 on the valve body 60 side, and a portion on the valve main body 56 side through which the valve stem 59 penetrates (that is, A seat surface 82 is provided on a bush 83) provided in a valve rod 59 penetrating portion of the upper lid 66 mounted on the valve body 56, and these seat surfaces 81 and 82 are configured to abut in an airtight state when fully opened. It is a point.

  That is, the seat surface 81 is formed at the end portion on the valve body 60 side in the sliding portion of the valve stem 59. Further, a bush 83 is assembled to a portion of the upper lid 66 where the valve rod 59 penetrates, and a seat surface 82 is provided on the bush 83. These seat surfaces 81 and 82 are sealed in contact with each other in an airtight state so that steam does not leak from the seat surfaces 81 and 82 when the steam control valve 42 is fully opened. These sheet surfaces 81 and 82 are preferably formed to have a tapered surface of 45 degrees, for example.

  Therefore, according to the present embodiment, in addition to the same effects (1) to (3) as in the first embodiment, the following effect (4) is achieved.

  (4) Seat surfaces 81 and 82 are respectively formed on the valve stem 59 that drives the valve body 60 and the bush 83 of the upper lid 66 that passes through the valve stem 59. When the seat surfaces 81 and 82 are fully opened, It is comprised so that it may contact | abut in an airtight state. This prevents the steam from flowing out from the leak-off hole 84 formed in the upper lid 66 when the steam control valve 42 is fully opened. As a result, for example, in a steam turbine power generation facility of a combined cycle, even when the steam control valve 42 is continuously operated at the fully opened position, the steam that flows into the steam turbine and should work effectively is wasted outside the system. Since the discharge is prevented, the efficiency of the steam turbine can be further improved.

  As mentioned above, although this invention was demonstrated based on said each embodiment, this invention is not limited to this. For example, in the present embodiment, the case where the steam valve device is the steam control valve 42 has been described. However, the steam valve device may be applied to other steam valve devices such as the main steam stop valve 41.

Sectional drawing which shows the fully closed state in the steam control valve which is 1st Embodiment of the steam valve apparatus which concerns on this invention. Sectional drawing which shows the micro opening degree state of the steam control valve of FIG. The longitudinal cross-sectional view which shows the intermediate opening state of the steam control valve 2 of FIG. The longitudinal cross-sectional view which shows the fully open opening state of the steam control valve of FIG. Sectional drawing which shows the dimension of each member in the steam control valve of the fully open state of FIG. The longitudinal cross-sectional view which shows the dimension of the valve-seat inlet part of FIG. The graph which shows the change characteristic of the flow-path area of the steam channel part shown in FIG.4 and FIG.5. Explanatory drawing for calculating | requiring the flow-path area of the steam channel part shown in FIG.4 and FIG.5. The system diagram which shows the electric power generation equipment equipped with the steam control valve shown in FIGS. The longitudinal cross-sectional view which shows the fully open opening state in the steam control valve which is 3rd Embodiment of the steam valve apparatus which concerns on this invention. The longitudinal cross-sectional view which shows the fully open opening state in the steam control valve which is 4th Embodiment of the steam valve apparatus which concerns on this invention. The longitudinal cross-sectional view which shows the fully open opening state in the steam control valve which is 5th Embodiment of the steam valve apparatus which concerns on this invention. The longitudinal cross-sectional view which shows the conventional steam valve apparatus (steam stop valve, steam control valve). The longitudinal cross-sectional view which shows the fully closed state of the steam control valve of FIG. The longitudinal cross-sectional view which shows the flow of the steam in the fully open opening state of the steam control valve of FIG.

Explanation of symbols

42 Steam control valve (steam valve device)
55 Power generation equipment 56 Valve body 56A Inner peripheral surface 57 Valve chamber 58 Valve seat 59 Valve rod 60 Valve body 61 Edge 62 Recessed portion 63 Chamber member 64 Flow guide 65 Steam passage portion 67 Top portion 70, 78 Outer surface 79 Straight line 80 Flat portion 81, 82 Sheet surface O1 center

Claims (15)

A valve chamber is formed by the valve body, the valve body is provided with a valve seat having a spherical curved surface at a position facing the valve chamber, and the valve chamber is driven by a valve rod and has a spherical curved surface. In the steam valve device in which the valve opening is set by contacting and separating the spherical curved surfaces of these valve seats and valve bodies,
On the bottom side of the valve body, a concave portion having an edge on the edge is provided,
The valve body side is provided with a chamber member located outside the valve body, and a flow guide disposed in the recessed portion of the valve body,
A steam valve device configured to form a steam passage portion at or near the full opening degree by the chamber member, the valve body, the flow guide, the inner surface of the valve body, and the valve seat. The steam valve device according to claim 1, wherein the flow guide is integrally fixed to the chamber member. The said valve body is formed in the cylindrical shape which has a top part, and a recessed part is provided inside, The diameter Di of the edge of this recessed part is the internal diameter of the said valve body, The Claim 1 or 2 characterized by the above-mentioned. The steam valve device described in 1. The flow passage area of the steam passage portion is configured to gradually and smoothly change from the upstream side toward the downstream valve seat side until finally reaching the opening area of the valve seat. The steam valve device according to any one of claims 1 to 3, wherein: The steam valve device according to any one of claims 1 to 4, wherein the steam passage portion is configured such that a flow passage area of a portion constituted by a valve body and a valve seat is minimized. The steam valve device according to any one of claims 1 to 5, wherein the flow guide has a central portion protruding in a convex shape toward the downstream valve seat side, and a tip of the flow guide is tapered. The longitudinal cross-sectional shape of the surface which forms the vapor | steam channel | path part of the said flow guide is provided with the reverse curvature part which consists of a curve of the curvature which has a center in the exterior of the said flow guide. The steam valve device described in 1. The vertical cross-sectional shape of the surface forming the steam passage portion of the flow guide is formed as a straight line circumscribing the spherical curved surface at the edge end of the valve body when the opening degree is fully open. A steam valve device according to claim 1. 9. The flow guide according to claim 1, wherein a central portion protrudes in a convex shape toward the downstream valve seat side, a tip end thereof is tapered, and a flat portion is provided at the forefront. The steam valve device according to any one of the above. When the edge diameter Di of the recessed portion of the valve body is set to Do, the seat diameter of the valve seat contacting the valve body,
[Equation 1]
Do> Di ≧ 0.9 Do
And the inner diameter Dth of the valve seat is
[Equation 2]
Di> Dth ≧ 0.8 Do
The steam valve device according to any one of claims 1 to 9, wherein the steam valve device is set in a range of. When the radius of curvature R of the valve body is Do, the seat diameter of the valve seat in contact with the valve body is
[Equation 3]
R = (0.52-0.6) Do
And the radius of curvature r of the valve seat is
[Equation 4]
r ≧ 0.6 Do
The steam valve device according to any one of claims 1 to 10, wherein the steam valve device is set in a range of. When the radius of curvature R of the valve body is Do, the seat diameter of the valve seat in contact with the valve body is
[Equation 5]
R = (0.52-0.6) Do
And the radius of curvature r of the valve seat is
[Equation 6]
r = (0.45-0.85) Do
The steam valve device according to any one of claims 1 to 10, wherein an inlet of the valve seat and an inner surface of the surrounding valve body are formed in a bell mouth shape. . The longitudinal cross-sectional shape of the inner surface of the valve body in the vicinity of the valve seat is connected to the valve seat with a curve circumscribing the curvature radius r of the valve seat, or circumscribes the curvature radius r of the valve seat and has an arbitrary angle. The steam valve device according to any one of claims 1 to 11, wherein the steam valve device is formed in a shape connected to the valve seat by a straight line having a straight line. A seat surface is provided at an end of the valve stem on the valve body side, a seat surface is provided at a portion on the valve body side through which the valve stem penetrates, and these seat surfaces are configured to abut in an airtight state when fully opened. The steam valve device according to any one of claims 1 to 13, wherein the steam valve device is provided. A power generation facility comprising the steam valve device according to any one of claims 1 to 14.

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