Globe valve

Abstract

To reduce both of deviation of a main flow of a fluid and a decrease in a capacity coefficient.SOLUTION: A globe valve 10 is equipped with a valve body 11, a seat ring 15 that is installed in the middle of an S-shaped channel R inside the valve body 11, and a valve element 12 that abuts on the seat ring 15 to open / close the S-shaped channel R. The channel R is equipped with an intermediate channel R10, a primary channel R20 that reaches from an inflow port E1 to a lower end portion R11 of the intermediate channel R10, and a secondary channel R30 that reaches from an upper end portion R12 of the intermediate channel R10 to an outflow port E2 and stores the valve element 12. A straightening partition wall 29 projecting out from a valve bottom 21F of the valve body 21 to the inside of a spherical channel R23 directs at least a part of a fluid flowing into the spherical channel R23 and striking on the straightening partition wall 29 to the intermediate channel R10 side and to the inflow port E1 side, thereby increase a flow rate of the fluid flowing on the inflow port E2 side of the intermediate channel R10.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a globe valve having a secondary flow path on the side where a valve body is disposed.

Background Art

[0002] A globe valve has a seat ring installed in the middle of a flow path and a valve body that moves relative to this seat ring, and the valve body abuts against the seat ring to close the flow path. The capacity coefficient of the globe valve is adjusted by changing the relative position of the valve body with respect to the seat ring at full open to adjust the area of the throttle. The specific throttle area is the lateral area of a frustum of a cone obtained by integrating a line segment of the minimum distance drawn from a certain point on the seat ring toward the plug over the entire circumference of the seat ring. This lateral area is called the apparent flow path area. When the apparent flow path area becomes relatively large with respect to the area of the inlet of the globe valve, there arises a problem that the main flow is biased toward the outlet side. To prevent this bias of the main flow, Patent Document 1 discloses a technique of disposing a flow separator that separates the flow of fluid into a plurality of separate flow paths in the flow path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique described in Patent Document 1 above, since a member in which, for example, plate materials are assembled in a lattice pattern to partition a plurality of separate flow paths is required, the capacity coefficient decreases.

[0005] The present invention has been made in view of the above points, and an object thereof is to reduce both the bias of the main flow of fluid and the decrease in the capacity coefficient.

Means for Solving the Problems

[0006] To solve the above problems, the globe valve according to the present invention comprises a valve body having an S-shaped flow path formed inside through which fluid flows, a seat ring installed in the middle of the S-shaped flow path inside the valve body, and a valve element that closes the S-shaped flow path by contacting the seat ring, wherein the S-shaped flow path is composed of at least the internal space of the seat ring, which is formed in the middle of the S-shaped flow path of the valve body and extends along the axial direction of the valve element, and the internal space of the seat ring installed in the through passage, and the valve element is in a closed state when it contacts the seat ring and is in an open state when it moves away from the seat ring, and the S-shaped flow path The valve comprises a primary flow path from the inlet to the first end of the intermediate flow path on the valve bottom side of the valve body, and a secondary flow path from the second end of the intermediate flow path opposite to the first end to the outlet of the S-shaped flow path, and housing the valve body. The primary flow path includes a spherical flow path connected to the first end of the intermediate flow path, and a flow straightening partition is provided that protrudes into the spherical flow path from the valve bottom that partitions the spherical flow path of the valve body, and the flow straightening partition is shaped to direct at least a portion of the fluid that flows into the spherical flow path and hits the flow straightening partition toward the intermediate flow path and the inlet side, thereby increasing the flow rate of the fluid flowing on the inlet side of the intermediate flow path compared to when the flow straightening partition is not provided.

[0007] As an example, the flow straightening partition extends from the center of the valve base to the inner surface of the valve body that demarcates the portion of the spherical flow path on the outlet side.

[0008] As an example, the ridge of the rectifying partition wall gradually rises from the central part of the valve base toward the inner surface. [Effects of the Invention]

[0009] According to the present invention, both the bias in the main flow of the fluid and the decrease in the volume coefficient are reduced. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a cross-sectional view of a globe valve according to a first embodiment of the present invention. [Figure 2] Figure 2 is a perspective cross-sectional view of a globe valve according to the first embodiment of the present invention. [Figure 3] Figure 3 shows the fluid velocity vectors in the cross-section of Figure 1 (a cross-section with the central axis and the plane passing through the left and right directions as the cutting plane), as analyzed by CFD (Computational Fluid Dynamics). [Figure 4] Figure 4 shows the fluid velocity vectors for the comparative example. [Figure 5] Figure 5 is a cross-sectional view of a globe valve according to a second embodiment of the present invention. [Figure 6] Figure 6 is a perspective cross-sectional view of a globe valve according to a second embodiment of the present invention. [Figure 7] Figure 7 shows the fluid velocity vectors in the AA section of Figure 6, as analyzed by CFD. [Figure 8] Figure 8 shows the fluid velocity vectors in section AA of Figure 6, analyzed using CFD, superimposed onto a perspective cross-sectional view of the globe valve. [Figure 9] Figure 9 shows the fluid velocity vectors in the cross-section of Figure 6 (a cross-section with the central axis and the plane passing through the left and right directions as the cutting plane), as analyzed by CFD. [Figure 10] Figure 10 shows the fluid velocity vectors for the comparative example. [Figure 11] Figure 11 is a cross-sectional view of a globe valve according to a modified example of the first embodiment. [Figure 12] Figure 12 is a cross-sectional view of a globe valve according to a modified example of the first embodiment. [Modes for carrying out the invention]

[0011] Hereinafter, a globe valve according to an embodiment of the present invention will be described with reference to the drawings.

[0012] [First Embodiment] As shown in FIG. 1, the globe valve 10 according to this embodiment includes a valve body 11, a valve element 12, a valve shaft 13, a lid 14, and a seat ring 15. These are formed of various metal materials. In particular, the seat ring 15 is formed of a metal material such as SUS316. Among the above members, the valve element 12 and the valve shaft 13 are integrally formed as a valve plug. Note that the valve element 12 and the valve shaft 13 may be formed separately. In this case, the valve shaft 13 is inserted into an insertion hole provided in the valve element 12 and connected to the valve element 12. Although not shown, the globe valve 10 further includes an actuator having an operating shaft connected to the valve shaft 13. The actuator moves the valve shaft 13 or the valve element 12 in the vertical direction by moving the operating shaft in the vertical direction.

[0013] The vertical direction, which is the moving direction of the valve element 12, is the axial direction of the central axis C of the valve element 12 and the valve shaft 13 (hereinafter also referred to as the axial direction). The vertical direction and the left - right direction orthogonal to it are directions for explanation, and may not coincide with the actual vertical and horizontal directions (directions orthogonal to the horizontal direction) depending on the installation orientation of the globe valve 10. The lower side in the vertical direction is the valve bottom 11F side of the valve body 11. The valve bottom 11F is the bottom portion of the valve body 11 facing the valve element 12.

[0014] An S - shaped flow path R through which fluid flows is formed inside the valve body 11. The seat ring 15 is installed in the middle of this flow path R. The S - shaped flow path R includes an intermediate flow path R10, a primary flow path R20 on the upstream side, and a secondary flow path R30 on the downstream side. The intermediate flow path R10 is also partitioned by the seat ring 15 installed in the middle of the flow path R. The fluid inlet E1 and the fluid outlet E2 of the flow path R face in opposite left - right directions.

[0015] The valve body 11 is a hollow member, and the opening at the upper center is closed by a lid 14. A valve shaft 13 penetrates through the lid 14 so as to be movable in the vertical direction. The valve body 11 includes a partition wall 11A that partitions a primary flow path R20 and a secondary flow path R30. At the center of the partition wall 11A, a circular cross-section through-hole H extending along the vertical direction (axial direction of the valve body) coaxially with the valve body 12 is formed. The through-hole H includes a lower through-hole H1 and an upper through-hole H2. The upper through-hole H2 is formed in a cylindrical shape. The diameter of the lower through-hole H1 is smaller than that of the upper through-hole H2 at the upper end, and gradually increases from the upper end toward the lower end.

[0016] The seat ring 15 is cylindrical and is fixed to the partition wall 11A in a state of being inserted into the upper through-hole H2 of the through-hole H. Thereby, the seat ring 15 is installed in the upper through-hole H2 of the through-hole H.

[0017] The lower through-hole H1, which is the portion of the through-hole H where the seat ring 15 is not installed, constitutes the lower end portion (first end portion) R11 of the intermediate flow path R10. The internal space defined by the inner peripheral surface of the seat ring 15 constitutes the upper end portion (second end portion) R12 of the intermediate flow path R10. The central axis of the intermediate flow path R10 is the central axis C. The lower end portion R11 may be the lower part including the lower end of the intermediate flow path R10. The upper end portion R12 may be the upper part including the upper end of the intermediate flow path R10. That is, the intermediate flow path R10 may consist only of both the lower end portion R11 and the upper end portion R12, and may not have an intermediate portion between the lower end portion R11 and the upper end portion R12.

[0018] The intermediate flow path R10, which includes the lower end R11 and the upper end R12, extends along the vertical direction. The intermediate flow path R10 is located below the valve body 12 and is opened and closed by the valve body 12, which moves in the vertical direction. When the valve body 12 moves downward, a part of it enters the interior of the seat ring 15 and contacts the seat ring 15, closing the intermediate flow path R10. Conversely, when the valve body 12 moves upward and separates from the seat ring 15, the intermediate flow path R10 is opened. By adjusting the distance between the seat ring 15 and the valve body 12, the flow rate of the fluid flowing through the S-shaped flow path R of the globe valve 10 is adjusted.

[0019] The primary flow path R20 is a curved flow path that extends from the inlet E1 of the S-shaped flow path R to the lower end (valve bottom 11F side end) R11 of the intermediate flow path R10. The primary flow path R20 comprises a flow path R21 extending to the right from the inlet E1, a flow path R22 extending downward to the right from flow path R21, and a flow path R23 extending to the right from flow path R22 and connected to the lower end R11 of the intermediate flow path R10.

[0020] The flow path R23 is located on the valve bottom 11F side of the valve body 11, directly below the intermediate flow path R10. The upper end of the flow path R23 is connected to the lower end R11 of the intermediate flow path R10. The flow path R23 is a spherical flow path formed in a spherical shape. More specifically, the flow path R23 is formed in a flattened hemispherical shape that is convex downwards. When viewed from above, the lower end R11 of the intermediate flow path R10 is located inside the flow path R23. In other words, when viewed from above, the outer edge of the flow path R23 is located outside the lower end R11 of the intermediate flow path R10, and the flow path R23 can be described as a vase shape as an example of a spherical shape.

[0021] The secondary flow path R30 is a curved flow path extending from the upper end R12 of the intermediate flow path R10 to the outlet E2. The secondary flow path R30 comprises a flow path R31 that houses the valve body 12, a flow path R32 that extends downward and to the right from flow path R31, and a flow path R33 that extends from flow path R32 to the outlet E2. The central axis of flow path R33 coincides with the central axis of flow path R21 that extends from the inlet E1, and extends along the left-right direction perpendicular to the central axis C.

[0022] The inner surface 11B of the valve body 11, which forms the lower end R11 of the intermediate flow path R10, is curved all around from top to bottom, that is, from the upper end R12 side to the valve bottom 11F side, gradually moving away from the central axis C, which is the central axis of the intermediate flow path R10. The inner surface 11B is curved diagonally downward, that is, bulging in the direction of the central axis C and the valve bottom 11F side. The cross-section of the inner surface 11B is curved in an arc shape, and its curvature is constant all around. Such an inner surface 11B is smoothly connected to the ceiling surface 11C of the primary flow path R20 which is connected to the lower end R11. The curved inner surface 11B will hereafter also be referred to as the curved surface 11B.

[0023] In this embodiment, the curved surface 11B reduces the bias of the main flow (the part with a relatively high flow velocity and high flow rate) of the fluid flowing through the globe valve 10. This point will be explained with reference to Figures 3 and 4.

[0024] In the comparative example shown in Figure 4, the inner surface of the lower end R11 of the intermediate channel R10 is cylindrical, similar to the conventional technology. In this case, the fluid flowing from the primary channel R20 into the intermediate channel R10 separates from the inlet side portion D1 of the cylindrical surface D, and a separation vortex V1 is generated near the inlet side portion D1. As a result, the main flow of fluid through the intermediate channel R10 is biased towards the side closer to the outlet E2.

[0025] On the other hand, as in this embodiment, by dividing the lower end R11 of the intermediate flow path R10 with a curved surface 11B, as shown in Figure 3, the fluid from the primary flow path R20 flows along the curved surface 11B on the inlet side, and separation vortices can be reduced or eliminated compared to the comparative example. As a result, the main flow can be moved toward the central axis C compared to the comparative example, reducing the bias of the main flow of the fluid flowing through the intermediate flow path R10 toward the outlet E2, and increasing the flow rate passing through the side farther from the outlet E2, i.e., the inlet E1 side. Furthermore, the net flow path area of ​​the fluid can be made the same as or close to the apparent flow path area, and the decrease in the capacity coefficient is also reduced. As described above, in this embodiment, both the bias of the main flow of the fluid and the decrease in the capacity coefficient are reduced. Furthermore, in this embodiment, the curved surface 11B can prevent the occurrence of cavitation caused by a local increase in fluid velocity. In addition, in this embodiment, the above effects can be obtained only by changing the shape of the valve body 11, which is superior in terms of cost and reliability.

[0026] Furthermore, in this embodiment, since the inner surface 11B of the lower end R11 of the intermediate flow path R10 is curved around its entire circumference, the formation of the valve body 11 is easier than in the case where part of it is not curved.

[0027] [Second Embodiment] The globe valve 20 according to the second embodiment will be described below. In the following description, elements having the same function as those in the first embodiment will be denoted by the same reference numerals, and detailed explanations will be omitted.

[0028] As shown in Figures 5 and 6, the globe valve 20 comprises a valve body 21, a valve element 12, a valve stem 13, a cover 14, and a seat ring 25. The globe valve 20 also includes an actuator (not shown), similar to the first embodiment.

[0029] The valve body 21, similar to the first embodiment, forms an S-shaped flow path R comprising an intermediate flow path R10, an upstream primary flow path R20, and a downstream secondary flow path R30.

[0030] The valve body 21, like the valve body 11, includes a partition wall 21A that separates the primary flow path R20 and the secondary flow path R30. A circular cross-section through-passage H is formed in the center of the partition wall 21A, extending vertically and coaxially with the valve body 12. Similar to the first embodiment, a seat ring 25 that cooperates with the valve body 12 to open and close the intermediate flow path R10 is inserted into and fixed in this through-passage H.

[0031] In this embodiment, the intermediate flow path R10 is formed solely by the inner circumferential surface of the seat ring 25. In other words, the internal space of the seat ring 25 constitutes the intermediate flow path R10. Unlike the first embodiment, the inner surface that demarcates the lower end of the seat ring 25 is a tapered surface 25A. This tapered surface 25A can reduce the separation vortex to some extent, although not to the same degree as the curved surface 11B.

[0032] In this embodiment, a flow straightening partition 29 is provided on the valve base 21F of the valve body 11 that partitions a spherical (particularly flattened hemispherical) flow path R23 located directly below the intermediate flow path R10. This flow straightening partition 29 is provided projecting from the valve base 21F into the interior of the flow path R23. The flow straightening partition 29 is flat and extends in the vertical, horizontal, and vertical directions. The flow straightening partition 29 extends from the central part of the valve base 21F (for example, a predetermined area through which the central axis C passes) to the inner surface 21G on the outlet E2 side of the valve body 11, which partitions the portion of the flow path R23 on the outlet E2 side. The ridge of the flow straightening partition 29 is configured to gradually rise from the central part of the valve base 21F toward the inner surface 21G.

[0033] Due to its shape, the flow straightening partition 29 directs at least a portion of the fluid flowing into the flow path R23 and hitting the partition 29 toward the intermediate flow path R10 and the inlet E1. As a result, the flow rate of the fluid flowing on the inlet E1 side of the intermediate flow path R10 is greater than when the flow straightening partition 29 is not provided. This point will be explained with reference to Figures 7 to 10.

[0034] As shown in Figures 7 and 8, the fluid flowing into the flow path R23 of the primary flow path R20 includes fluid flowing along the inner wall of this flow path R23. This fluid includes fluid that, upon contact with the flow straightening partition 29, changes direction towards the intermediate flow path R10 and the inlet E1 side, i.e., towards the upper left (see arrow Z in Figures 7 and 8). This changed fluid flow will be called "diverted flow". This diverted flow flows into the flow path R23 along the upper flow path wall of the primary flow path R20, directing the fluid that would otherwise flow towards the outlet E2 side of the seat ring 25 toward the vicinity of the inlet E1 side of the seat ring 25. As a result, as shown in Figures 9 and 10, compared to the comparative example without the flow straightening partition 29 (Figure 10), the flow rate of fluid flowing on the inlet E1 side of the intermediate flow path R10 can be increased, and the bias of the main fluid flowing in the intermediate flow path R10 toward the outlet E2 side is reduced. Furthermore, the net fluid flow area can be made the same as, or close to, the apparent flow area, and the decrease in the volume coefficient is also reduced. As described above, in this embodiment, both the bias of the fluid main flow and the decrease in the volume coefficient are reduced. Moreover, in this embodiment, the occurrence of cavitation caused by a local increase in fluid velocity can be prevented. In addition, in this embodiment, the above effects can be obtained by changing only the shape of the valve body 21, which is superior in terms of cost and reliability.

[0035] As described above, the flow straightening partition 29 extends from the center of the valve base 21F to the inner surface 21G on the outlet E2 side of the valve body 11. Therefore, within the flow path R23, the flow straightening partition 29 is positioned diagonally to the portion of the intermediate flow path R10 on the inlet E1 side. This makes it easier for the fluid flowing in the portion of the flow path R23 on the outlet E2 side to flow toward the intermediate flow path R10 and the inlet E1 side, i.e., toward the upper left, due to the flow straightening partition 29. This increases the flow rate of the fluid flowing toward the inlet E1 side of the intermediate flow path R10 and reduces the bias of the main fluid flowing in the intermediate flow path R10 toward the outlet E2 side.

[0036] Furthermore, as described above, the ridge of the rectifying partition wall 29 is configured to gradually rise from the center of the valve base 21F toward the inner surface 21G, thereby suppressing interference between the rectifying partition wall 29 and the valve body 12 when the valve body 12 moves downward. In examples such as Figure 5, there is no risk of interference in the first place, but if the valve body 12 is formed in a shape that has a larger portion that fits into the seat ring 25 than the shape in Figure 5, the aforementioned shape of the rectifying partition wall 29 becomes effective.

[0037] [Differentiation] The features of the first and second embodiments described above may be combined. For example, as shown in Figure 11, a flow straightening partition 29 may be provided in the globe valve 10 according to the first embodiment. This provides the effects of the flow straightening partition 29 in addition to the effects of adopting the curved surface 11B, further reducing both the bias of the main fluid flow and the decrease in the capacity coefficient. Alternatively, as shown in Figure 4, the flow straightening partition 29 may be provided in a structure where the inner surface that partitions the lower end R11 of the intermediate flow path R10 is not curved. This also reduces both the bias of the main fluid flow and the decrease in the capacity coefficient to some extent.

[0038] As shown in Figure 12, the inner surface of the lower end of the seat ring 25 of the globe valve 20 according to the second embodiment, that is, the inner surface that defines the lower end of the intermediate flow path R10, may be curved as in the first embodiment, instead of being a tapered surface 25A. In other words, the inner surface of the lower end of the seat ring 25 that defines the lower end of the intermediate flow path R10 may be a curved surface 25T that is curved from top to bottom, that is, from the upper end R12 side to the valve bottom 21F side, gradually moving away from the central axis C, and bulging diagonally downward, that is, towards the central axis C side and the valve bottom 21F side. In the second embodiment, although the tapered surface 25A does not cause large fluid separation like in the comparative example in Figure 4, some separation may occur, so it is better to provide a curved surface 25T to reduce separation.

[0039] When the inner surface that demarcates the lower end of the intermediate flow path R10 is curved, only the inner surface on the inlet E1 side may be curved, and this also reduces both the bias of the main fluid flow and the decrease in the volume coefficient. The cross-section of the curved inner surface may be, for example, an arc shape with an inner angle of 90 degrees (including approximately 90 degrees). This effectively reduces the separation described above.

[0040] The shapes of the individual elements constituting the globe valves 10 and 20 can be modified as appropriate. For example, the flow straightening partition 29 does not have to be aligned in the left-right direction. The flow straightening partition 29 may be provided with holes (e.g., bottomed holes) to reduce weight.

[0041] [Expected range] Although the present invention has been described above with reference to embodiments and modifications, the present invention is not limited to the above embodiments and modifications. For example, the present invention includes various modifications to the above embodiments and modifications that can be understood by those skilled in the art within the scope of the technical concept of the present invention. The configurations listed in the above embodiments and modifications can be combined as appropriate to the extent that they do not contradict each other. [Explanation of symbols]

[0042] 10... Globe valve, 11... Valve body, 11A... Partition, 11B... Inner surface (curved surface), 11C... Ceiling surface, 11F... Valve base, 12... Valve body, 13... Valve stem, 14... Cover, 15... Seat ring, 20... Globe valve, 21... Valve body, 21A... Partition, 21F... Valve base, 21G... Inner surface, 25... Seat ring, 25A... Tapered surface, 25T... Curved surface, 29... Flow straightening partition, C... Center Center axis, D...Cylindrical surface, D1...Inlet side portion, E1...Inlet, E2...Outlet, H...Through passage, H1...Lower through passage, H2...Upper through passage, R...Flow path, R10...Intermediate flow path, R11...Lower end, R12...Upper end, R20...Primary flow path, R21...Flow path, R22...Flow path, R23...Flow path, R30...Secondary flow path, R31...Flow path, R32...Flow path, R33...Flow path, V1...Separation vortex.

Claims

[Claim 1] A globe valve comprising: a valve body having an S-shaped flow path formed inside through which fluid flows; a seat ring installed in the middle of the S-shaped flow path inside the valve body; and a valve element that closes the S-shaped flow path by contacting the seat ring, The aforementioned S-shaped channel is An intermediate passage is formed at a position midway through the S-shaped flow path of the valve body and extends along the axial direction of the valve body, and the internal space of the seat ring installed in the through passage, and is composed of at least the internal space of the seat ring, wherein the valve body is in a closed state when it contacts the seat ring, and is in an open state when it moves away from the seat ring, A primary flow path from the inlet of the S-shaped flow path to the first end of the intermediate flow path on the valve bottom side of the valve body, The intermediate flow path extends from the second end opposite to the first end to the outlet of the S-shaped flow path and includes a secondary flow path that houses the valve body, The primary channel comprises a spherical channel connected to the first end of the intermediate channel, A flow-straightening partition is provided that protrudes from the valve bottom, which divides the spherical flow path of the valve body, into the interior of the spherical flow path. The aforementioned flow straightening partition is It extends from the central part of the valve base to the inner surface of the valve body that demarcates the portion of the spherical flow path on the outlet side, The ridge of the flow-rectifying partition wall gradually rises from the central portion to the inner surface, and extends in a straight line from the central portion to the inner surface. By directing at least a portion of the fluid that flows into the spherical channel and strikes the flow straightening partition toward the intermediate channel and the inlet side, the flow rate of the fluid flowing toward the inlet side of the intermediate channel is increased compared to the case where the flow straightening partition is not provided. Globe valve.

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