Turbine shaft seal device

Abstract

To suppress an axial vibration of a rotational part by reducing a reactive force when the rotation part comes into contact with a packing ring segment.SOLUTION: A turbine shaft seal device 100 suppresses a leakage of work fluid from a gap between a lower-half stationary part 20u and an upper-half stationary part 20v annually surrounding a rotational part 10 of the turbine and the rotational part 10. Six packing ring segments of the turbine shaft seal device 100 includes a lower-half enter segment 31 and two lower-half lateral segments 32, and an upper-half center segment 33 and two lower-half lateral segments 34. The packing ring segments configures an annular packing ring having a hook that fits with a hook fitting annular grooves of the lower-half stationary part 20u and the upper-half stationary part 20v, and an inner peripheral ring part in which a seal fin projecting on a rotation part-side is provided. Urging means includes: lower-half center urging means 31s, lower-half lateral urging means 32s, upper-half lateral urging means 34s, and upper-half center urging means 34j.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to a turbine shaft seal device.

Background Art

[0002] During the transient operation of starting and stopping a turbine, a temperature difference may occur between the upper and lower parts of the turbine casing, which is a stationary part, due to the non-uniformity of the steam flow. Due to this temperature difference, the entire casing may be thermally deformed in an arcuate shape vertically upward or downward, increasing the contact risk between the rotating part and the stationary part in the upper and lower parts. Also, although the rotational speed changes during the start-up and stop of the turbine, resonance occurs when passing through the natural vibration frequency of the turbine rotor, increasing the vibration of the turbine rotor. Due to such events, the rotating part and the stationary part may come into contact in the upper and lower parts between the rotating part and the stationary part.

[0003] When the turbine shaft seal comes into contact in the vertical direction, heat generation due to friction occurs, locally increasing the temperature of the rotor and causing thermal bending, with a risk of generating shaft vibration. To reduce heat generation due to friction, it is important to reduce the reaction force from the stationary part to the rotating part, i.e., the force that pushes back the rotating part, when the rotating part and the stationary part come into contact.

[0004] FIG. 14 is a partial longitudinal sectional view showing a conventional configuration example of a turbine shaft seal device.

[0005] The turbine shaft seal device is disposed between a rotating part 10 and a stationary part 20. In a conventional configuration, the turbine shaft seal device is composed of an annular packing ring 30 held by the stationary part 20 and surrounding the rotating part 10, and support keys and respective springs shown in FIG. 15 later. Here, the spring is a coil spring, a leaf spring, or other biasing means having an elastic force.

[0006] The packing ring 30 has an annular inner peripheral ring portion 35 as an inner portion in the radial direction and an outer peripheral ring portion 39 as an outer portion in the radial direction.

[0007] On the inner peripheral surface of the inner peripheral ring portion 35, seal fins 38 are provided to reduce the flow rate of the working fluid passing through the gap between the rotating portion 10 and the packing ring 30. In FIG. 14, a case is illustrated where a plurality of convex portions are formed in the axial direction on the outer peripheral surface 10a of the rotating portion 10 facing the inner peripheral surface of the inner peripheral ring portion 35, but there may also be a case where they are not formed.

[0008] The outer peripheral ring portion 39 is engaged with a hook fitting annular groove 23 formed in the stationary portion 20, whereby the packing ring 30 is statically supported by the stationary portion 20. The upstream side portion of the outer peripheral ring portion 39 forms a front hook 36. Also, the downstream side portion of the outer peripheral ring portion 39 forms a rear hook 37. On the other hand, the stationary portion 20 has an annular groove front side convex portion 24 and an annular groove rear side convex portion 25 before and after the entrance of the hook fitting annular groove 23 on its inner peripheral surface 20a. The movement of the packing ring 30 radially inward is such that the inner peripheral surface 36a of the front hook of the front hook 36 contacts the outer peripheral surface 24a of the front side convex portion of the annular groove front side convex portion 24, and the inner peripheral surface 37a of the rear hook of the rear hook 37 contacts the outer peripheral surface 25a of the rear side convex portion of the annular groove rear side convex portion 25, respectively, so as to maintain a minimum gap without the seal fins 38 contacting the rotating portion 10. Note that the sealing function by the inner peripheral surface 37a of the rear hook 37 and the outer peripheral surface 25a of the annular groove rear side convex portion 25 is essential.

[0009] The packing ring 30 generally has a structure divided in the circumferential direction from the viewpoint of assemblability. FIG. 14 is a partial longitudinal cross - section of each packing ring segment 50a as a dividing element of the packing ring 30.

[0010] Next, the circumferential configuration of the divided structure will be described. Note that the stationary portion 20 also has a structure divided in the circumferential direction from the viewpoint of assemblability, and generally, it is divided vertically.

[0011] FIG. 15 is a cross - sectional view showing a conventional configuration example of the turbine shaft seal device. In FIG. 15, for the purpose of subsequent explanation, a state is shown where the rotating portion 10 has moved downward more than usual.

[0012] As shown in FIG. 15, the packing ring 30 is composed of four packing ring segments 50a divided in the circumferential direction. Specifically, it consists of two lower half segments 51 arranged below the horizontal dividing surface 20h of the stationary part 20 and two upper half segments 52 arranged above the horizontal dividing surface 20h of the stationary part 20. These four segments each have a circumferential angle of 90 degrees in the circumferential direction.

[0013] Note that the stationary part 20 is divided into a lower half stationary part 20u and an upper half stationary part 20v. The lower ends of the two upper half segments 52 are respectively supported by support keys 40 attached to the upper half horizontal coupling surface 22 of the upper half stationary part 20v of the stationary part 20. Also, the interval between the circumferential end faces of the two upper half segments 52 is adjusted by the support keys 40.

[0014] On the side close to the bottom of each of the two lower half segments 51, two spring storage holes 51h formed toward the rotation center axis CL are formed, and lower half springs 51s for biasing the lower half segments 51 toward the rotation center axis CL are stored in the respective spring storage holes 51h.

[0015] The biasing force of the lower half springs 51s is set to be slightly larger than the weight of the lower half segments 51 by a small amount Δf1. As a result, in a state where there is no contact with the rotating part 10, a minimum gap is ensured between each lower half segment 51 and the rotating part 10. On the other hand, when the rotating part 10 comes into contact with the two lower half segments 51, the two segments 51 can easily escape (move) radially outward, and no excessive friction occurs. That is, the difference between the total value of the biasing forces of the two lower half springs 51s and the total value of the weights of the two lower half segments 51 is set to be smaller than the force received when the rotating part 10 comes into contact.

[0016] In each of the two upper half segments 52, one spring storage hole 52h formed toward the rotation center axis CL is formed, and an upper half spring 52s that biases the upper half segment 52 toward the rotation center axis CL is stored in each spring storage hole 52h. Further, a spring storage hole 52a is formed in the end face at the boundary between one upper half segment 52 and the other upper half segment 52 in a direction perpendicular to the end face, and an upper half auxiliary spring 52j that acts in the direction of connecting the two upper half segments 52 is stored therein.

[0017] When the rotating part 10 comes into contact with the two upper half segments 52 at the top and the contact part further spreads in the circumferential direction, the upper half auxiliary spring 52j easily extends, and the two upper half segments 52 can move apart in the circumferential direction, so that excessive friction does not occur. That is, the biasing force of the upper half auxiliary spring 52j is set to be smaller than the force received when the rotating part 10 comes into contact by Δf2.

Prior Art Documents

Patent Documents

[0018]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0019] As described above, the biasing force F1 of the lower half spring 51s provided on the side closer to the bottom is set to be slightly larger than the weight W1 of the lower half segment 51 by Δf1. Although it is slight, setting it to be larger than the weight of the lower half segment 51 is for finally returning the lower half segment 51 to its original position when the contact of the rotating part 10 is lost.

[0020] As a result, when the rotating part 10 contacts the two lower half segments 51 in the bottom direction, the rotating part 10 will receive a force of Δf1 from each of the two lower half segments 51. When the rotating part 10 contacts the two lower half segments 51, heat generation due to friction occurs, the temperature of the rotating part 10 locally rises, causing thermal bending and resulting in shaft vibration in some cases.

[0021] Also, when the contact state is released, the lower half segment 51 tries to return to its original position due to the spring force of the lower half spring 51s. However, the lower half segment 51 that has slipped vertically downward under the influence of its own weight may have its movement restricted or stack with adjacent lower half segments 51 due to friction between them, and may not be able to completely return to its original position.

[0022] Also, for the two upper half segments 52 above, the biasing force of the upper half auxiliary spring 52j is set to be smaller by Δf2 than the force received when the rotating part 10 contacts. This is to finally return the upper half segment 52 to its original position when the contact with the rotating part 10 is lost.

[0023] Also, for the two upper half segments 52 above, when they contact the rotating part 10, the rotating part 10 receives a reaction force by separating the two upper half segments 52 in the circumferential direction, heat generation due to friction occurs, the temperature of the rotating part 10 locally rises, causing thermal bending and resulting in shaft vibration in some cases.

[0024] Also, when the top of the rotating part 10 contacts the two upper half segments 52, the two upper half segments 52 perform a pivoting operation with the support keys 40 as fulcrums respectively. After that, when the contact state is released, there is a risk that the seat surface of the upper half auxiliary spring 52j and the circumferential end face of one of the other upper half segments 52 will abut, inhibiting the movement of the upper half segment 52. Or, there was a risk that the circumferential end faces of the two upper half segments 52 would abut against each other, inhibiting the movement of the upper half segment 52 and not returning to its original position.

[0025] As described above, in the conventional structure, there is a problem that frictional heat due to the force received from the two lower half segments 51 or the two upper half segments 52 when the rotating part 10 comes into contact with them causes vibration of the rotating part 10. Further, there is a problem that the sealing performance deteriorates because the two lower half segments 51 or the two upper half segments 52 do not return to their original positions after coming into contact with the rotating part 10.

[0026] The problem to be solved by the present invention is to provide a turbine shaft seal device capable of reducing the force received by the rotating part when the rotating part of the turbine comes into contact with the packing ring segment and suppressing the axial vibration of the rotating part.

Means for Solving the Problem

[0027] To achieve the above object, the turbine shaft seal device in the present embodiment is a turbine shaft seal device arranged to annularly surround the rotating part of a turbine that rotates around the rotation center axis by a working fluid, and suppress leakage of the working fluid from between the lower stationary part and the upper stationary part that are arranged to be in close contact with each other vertically on their respective horizontal joint surfaces and the rotating part. The turbine shaft seal device includes a packing ring lower half and a packing ring upper half that constitute an annular packing ring having an inner peripheral ring part with a hook that fits into a hook fitting annular groove formed in the circumferential direction in the lower stationary part and the upper stationary part, and at least one seal fin that protrudes toward the surface of the rotating part and is formed in the circumferential direction. The packing ring lower half is statically supported by the lower stationary part and has a lower central segment arranged at the center in the circumferential direction of the lower half, and two lower side segments on both sides in the circumferential direction of the lower central segment, with one circumferential end of each facing the circumferential end of the lower central segment. The packing ring upper half is statically supported by the upper stationary part and has an upper central segment arranged at the center in the circumferential direction of the upper half, and two upper side segments on both sides in the circumferential direction of the upper central segment, with one circumferential end of each facing the circumferential end of the upper central segment and the other end being supported by a support plate provided on the horizontal joint surface of the upper stationary part. The turbine shaft seal device further includes lower central biasing means for biasing the lower central segment radially inward, lower side biasing means for biasing each of the two lower side segments radially inward, upper side biasing means for biasing each of the two upper side segments radially inward, the upper central segment, and two upper central biasing means provided between the upper central segment and each of the two upper side segments for biasing the upper central segment in a direction to bring it into close contact with each of the two upper side segments. This is the feature of the present invention.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Embodiments for Carrying Out the Invention

[0029] Hereinafter, with reference to the drawings, a turbine shaft sealing device according to an embodiment of the present invention will be described. Here, the same or similar parts are denoted by common reference numerals, and overlapping descriptions are omitted.

[0030] [First Embodiment] FIG. 1 is a conceptual partial longitudinal sectional view including the rotation center axis CL of the turbine 1 for explaining the rotating part 10 and the stationary part 20 of the turbine.

[0031] The turbine 1 has a rotating part 10 rotatably supported by a bearing (not shown) and a stationary part 20 arranged so as to surround the radially outer side of the rotating part 10. The rotating part 10 has a rotor 11 extending in the axial direction and a plurality of moving blade rows 12 attached to the rotor 11 and provided circumferentially with an axial interval therebetween. Further, on the inner peripheral surface of the stationary part 20, a stationary blade row 28 is provided as a part of the stationary part 20 on the upstream side of each moving blade row 12. The working fluid such as steam or gas introduced into the turbine 1 performs work while passing through the annular main flow path 2 formed by the stationary blade row 28 and the moving blade row 12, and then flows out of the turbine 1. Hereinafter, the upstream side of the flow of the working fluid may be referred to as the front side and the downstream side as the rear side.

[0032] On the other hand, a gap is provided between the inner peripheral surface of the stationary blade row 28 and the rotor 11, and thereby an annular first leakage flow path 3a, which is a bypass flow path of the main flow path 2, is formed. Also, a radial gap is provided between the moving blade row 12 and the inner peripheral surface of the stationary part 20, and thereby an annular second leakage flow path 3b, which is a bypass flow path of the main flow path 2, is formed. Thus, by providing a gap for preventing contact between the rotating part 10 and the stationary part 20, leakage flow paths 3 having an annular shape and an axial width such as the first leakage flow path 3a and the second leakage flow path 3b are formed.

[0033] Such a leakage flow path 3 is provided with a shaft seal device 100 for reducing the leakage flow rate. This suppresses the leakage flow of the working fluid and suppresses the efficiency reduction of the axial flow turbine. In an axial flow turbine installed in a power plant or the like, it is common to use a labyrinth seal device as the seal device.

[0034] On the other hand, during start-up and stop transient operations, another function is required for the shaft seal device. During the start-up and stop processes, the internal pressure of the turbine is not so high compared to the rated operation or partial load operation, and the differential pressure across the shaft seal device is also small. In such a state, the force pressing the inner diameter side by pressure is weak, and the shaft seal device can move in the radial direction. The turbine rotor has a natural frequency in the range below the rated rotational speed, and the shaft vibration increases when passing through the natural frequency during the start-up and stop processes. Here, the start-up process refers to the process of rising from a stopped state of 0 rpm or a turning rotational speed of about several rpm toward the rated rotational speed, and the stop process refers to the process of decreasing from the rated rotational speed toward the stopped state or the turning rotational speed, conversely.

[0035] During resonance, the contact risk increases between the turbine rotor with a narrow gap and the shaft seal device. When they come into contact, the turbine rotor generates heat due to friction, causing a local temperature rise and thermal bending, and generating shaft vibration. Furthermore, during the start-up and stop processes, the flow rate of the working fluid flowing into the turbine is also small, and a temperature difference may occur between the upper and lower parts due to the non-uniformity of the flow, compared to the rated operation. Along with this, a temperature difference occurs between the upper half and the lower half of the turbine casing, and the entire casing may deform bow-shaped vertically upward or downward, further increasing the contact risk. Therefore, as a means of reducing shaft vibration, during the start-up and stop processes, the shaft seal is required to have a function of reducing heat generation due to friction.

[0036] Note that hereinafter, as the leakage flow path 3, the case where the shaft seal device 100 is applied to the first leakage flow path 3a will be taken as an example for explanation, but the shaft seal device 100 can be similarly applied to the second leakage flow path 3b.

[0037] Also, since the shaft seal device 100 is statically supported by the stationary part 20, the shaft seal device 100 is a stationary part. For convenience of explanation, hereinafter, the shaft seal device 100 shall be treated as not being included in the stationary part 20.

[0038] FIG. 2 is a cross-sectional view perpendicular to the rotation center axis CL of the turbine 1 showing the configuration of the turbine shaft seal device 100 according to the first embodiment.

[0039] The turbine shaft seal device 100 includes a packing ring 30 and a target segment support structure 120 that supports a target segment 30x described later.

[0040] Here, the packing ring 30 has the same cross-sectional shape as the conventional packing ring 30 shown in FIG. 14 in terms of the cross-sectional shape. That is, the packing ring 30 has an annular inner peripheral ring portion 35 as the radially inner portion and an outer peripheral ring portion 39 as the radially outer portion.

[0041] Seal fins 38 are provided on the inner peripheral surface of the inner peripheral ring portion 35 to reduce the flow rate of the working fluid passing through the gap between the rotating part 10 and the packing ring 30.

[0042] The outer peripheral ring portion 39 is engaged with a hook fitting annular groove 23 formed in the stationary portion 20, whereby the packing ring 30 is statically supported by the stationary portion 20. The upstream side portion of the outer peripheral ring portion 39 forms a front hook 36. Also, the downstream side portion of the outer peripheral ring portion 39 forms a rear hook 37. On the other hand, the stationary portion 20 has an annular groove front side convex portion 24 and an annular groove rear side convex portion 25 before and after the inlet of the hook fitting annular groove 23 on its inner peripheral surface 20a. The movement of the packing ring 30 radially inward is such that the front hook inner peripheral surface 36a of the front hook 36 contacts the front convex portion outer peripheral surface 24a of the annular groove front side convex portion 24, and the rear hook inner peripheral surface 37a of the rear hook 37 contacts the rear convex portion outer peripheral surface 25a of the annular groove rear side convex portion 25, respectively, so as to maintain a minimum gap without the seal fin 38 contacting the rotating portion 10. Note that the sealing function by the rear hook inner peripheral surface 37a of the rear hook 37 and the rear convex portion outer peripheral surface 25a of the annular groove rear side convex portion 25 is essential. <Explanation of the first characteristic point>

[0043] The number of divisions of the packing ring 30 into packing ring segments 30a in the circumferential direction is six in this embodiment, as opposed to four in the prior art. That is, the packing ring 30 has a packing ring lower half 30u that engages with the lower stationary portion 20u and is statically supported by the lower stationary portion 20u, and a packing ring upper half 30v that engages with the upper stationary portion 20v and is statically supported by the upper stationary portion 20v.

[0044] The packing ring lower half 30u has a lower central segment 31 arranged at the center in the lower circumferential direction, and two lower side segments 32 arranged on both circumferential sides of the lower central segment 31. Also, the packing ring upper half 30v has an upper central segment 33 arranged at the center in the upper circumferential direction, and two upper side segments 34 arranged on both circumferential sides of the upper central segment 33.

[0045] The above six packing ring segments 30a of the lower half central segment 31, two lower half side segments 32, the upper half central segment 33, and two upper half side segments 34 constitute the packing ring 30 extending in the circumferential direction.

[0046] The sum of the circumferential angles of the lower half central segment 31 and the two lower half side segments 32, and the sum of the circumferential angles of the upper half central segment 33 and the two upper half side segments 34 are each 180 degrees. FIG. 2 shows a case where the six packing ring segments 30a are equally angularly divided.

[0047] Next, the springs related to each packing ring segment 30a will be described. Here, the spring is a coil spring, a leaf spring, or other biasing means having an elastic force. Also, each spring is housed in a spring housing hole formed in each packing ring segment 30a, and the end of the spring may be fixed to each spring housing hole, or may simply contact the deepest part of the spring housing hole. Also, in the case of simply contacting, the deepest part of the spring housing hole may be formed in a conical shape, for example, so that no displacement of the contact position occurs.

[0048] Two spring housing holes 31h are formed in the lower half central segment 31 so as to face the rotation center axis CL, and a lower half central spring 31s that biases the lower half central segment 31 toward the rotation center axis CL is housed in each spring housing hole 31h. The biasing force of the lower half central spring 31s is set to be slightly larger than the weight of the lower half central segment 31 by an amount ΔF1. Here, the smaller ΔF1 is, the smaller the reaction force on the rotating part 10 becomes, but it is necessary to ensure the minimum value in consideration of variations in spring rigidity and temporal degradation. The specific value of ΔF1 may be set based on actual results or may be an analytical value.

[0049] In each of the two lower side segments 32, two spring storage holes 32h are formed facing the rotation center axis CL, and a lower side spring 32s that biases the lower side segment 32 toward the rotation center axis CL is stored in each spring storage hole 32h.

[0050] Two types of springs are provided in each upper side segment 34. First, in a portion of the upper side segment 34 close to the horizontal division plane 20h, a spring storage hole 34h is formed facing the rotation center axis CL, and an upper side spring 34s that biases the upper side segment 34 toward the rotation center axis CL is stored in this spring storage hole 34h. Also, on the end face at the boundary between the upper side segment 34 and the upper center segment 33 of each upper side segment 34, a spring storage hole 34k is formed in a direction perpendicular to the end face, and an upper half auxiliary spring 34j that connects the upper side segment 34 and the upper center segment 33 is stored.

[0051] The coupling force between the upper side segment 34 and the upper center segment 33 by the upper half auxiliary spring 34j is set such that when the rotating portion 10 contacts the upper center segment 33 at the top, the upper half auxiliary spring 34j easily extends, and the upper center segment 33 and the two upper side segments 34 can easily separate in the circumferential direction. That is, the coupling force of the upper half auxiliary spring 34j is set to be smaller than the force received when the rotating portion 10 contacts by ΔF2. Here, the smaller ΔF2 is, the smaller the reaction force on the rotating portion 10 becomes, but it is necessary to ensure the minimum value in consideration of variations in spring stiffness and temporal degradation. The specific value of ΔF2 may be set based on actual results or analytical values.

[0052] Each of the two upper side segments 34 is supported at the end portion closer to the horizontal division plane 20h by a support key 40 provided on the horizontal division plane 20h of the upper half stationary portion 20v of the stationary portion 20. The interval between the circumferential end faces of each upper side segment 34 and the upper center segment 33 is adjusted by this support key 40.

[0053] The two lower side segments 32 are each supported by a turbine shaft seal device 100 provided on a horizontal dividing surface 20h of a lower stationary part 20u of a stationary part 20.

[0054] FIG. 3 is a cross-sectional view perpendicular to the rotation center axis CL of a turbine 1 showing a configuration of a modified example of a turbine shaft seal device 100 according to the first embodiment.

[0055] In the modified example, each of the six divided packing ring segments 30a is not equally divided. That is, they do not have equal circumferential angles. Here, the circumferential angle refers to the angle formed by a plane including one end in the circumferential direction of the packing ring segment 30a and the rotation center axis CL, and a plane including the other end in the circumferential direction and the rotation center axis CL. Alternatively, in a cross-section perpendicular to the axial direction, it is also the circumferential angle between both ends in the circumferential direction of the packing ring segment 30a, so it may also be called the circumferential angle between both ends in the circumferential direction.

[0056] If the circumferential angle of the lower central segment 31 is Θ1, the circumferential angle of the lower side segment 32 is Φ1, the circumferential angle of the upper central segment 33 is Θ2, and the circumferential angle of the upper side segment 34 is Φ2, then (Θ1 + 2·Φ1) and (Θ2 + 2·Φ2) are each 180 degrees.

[0057] The circumferential angles Θ1 of the lower central segment 31 and Θ2 of the upper central segment 33 are angles that satisfy predetermined conditions, respectively.

[0058] FIG. 4 is a conceptual cross-sectional view perpendicular to the rotation center axis CL of a turbine for explaining the circumferential angles of the packing ring segments 30a in a modified example of a turbine shaft seal device 100 according to the first embodiment. Specifically, it explains the conditions of the circumferential angle Θ1 of the lower central segment 31 and the circumferential angle Θ2 of the upper central segment 33. In FIG. 4, the case of the circumferential angle Θ1 of the lower central segment 31 is illustrated and explained, but the same applies to the circumferential angle Θ2 of the upper central segment 33.

[0059] In FIG. 4, it shows a state where the rotating part 10 contacts the lower half central segment 31 and the lower half central segment 31 is pressed downward. The outer circumference of the rotating part 10 in this state is C R and, also, the inner circumference of the lower half central segment 31 at the original position (the position before being pressed downward) is represented by a dashed line C S . Since the radius of curvature of the outer circumference of the rotating part 10 is smaller than the radius of curvature of the inner circumference of the lower half central segment 31, as shown in FIG. 4, the outer circumference C R of the rotating part 10 and the inner circumference C S of the lower half central segment 31 produce intersection points P1 and P2.

[0060] Here, if the angle formed by P1 - CL - P2, that is, the circumferential angle between the intersection points, is represented by Ψ, and if the circumferential angle Ψ between the intersection points is smaller than the circumferential angle Θ1 between the ends of the lower half central segment 31, the rotating part 10 will contact only the lower half central segment 31 without contacting the lower half side segment 32. That is, it will not receive the reaction force from the lower half side segment 32. Therefore, conversely, the condition is that the circumferential angle Θ1 between the ends of the lower half central segment 31 is larger than the circumferential angle Ψ between the intersection points.

[0061] On the other hand, if the circumferential angle Θ1 between the ends of the lower half central segment 31 is too large, the weight of the lower half central segment 31 will increase, and it is necessary to increase the rigidity of the lower half central spring 31s. As a result, when the rotating part 10 contacts the lower half central segment 31 and the lower half central segment 31 moves downward, the reaction force received by the rotating part 10 from the lower half central segment 31 will increase. Therefore, it is preferable that the circumferential angle Θ1 between the ends of the lower half central segment 31 is within a predetermined width ΔΘ larger than the circumferential angle Ψ between the intersection points. That is, it is preferable that Ψ < Θ1 < Ψ + ΔΘ. Here, ΔΘ can be appropriately selected, for example, 10 degrees or 20 degrees.

[0062] <Explanation of the action and effect of the first characteristic point> By dividing the packing ring 30 into six packing ring segments 30a (three each on the upper and lower sides) as described above, when the rotating part 10 moves up and down during operation and particularly comes into contact with the packing ring segment 30a below or above, it contacts only one packing ring segment 30a. As a result, the reaction force from the packing ring segment 30a can be kept low, and local temperature rise of the rotating part 10 and the resulting vibration can be suppressed.

[0063] <Description of the second characteristic point> Next, the target segment support structure 120, which is the second characteristic point of the present embodiment different from the conventional one, will be described.

[0064] FIG. 5 is a partial horizontal cross-sectional view showing the configuration of the target segment support structure 120 of the turbine shaft seal device 100 according to the first embodiment. FIG. 6 is a partial vertical cross-sectional view taken along the line A-A of FIG. 5 showing the configuration of the target segment support structure 120 of the turbine shaft seal device 100 according to the first embodiment. The dashed arrow in FIG. 5 indicates the direction from the upstream side to the downstream side of the working fluid. The same applies to FIGS. 8, 10, and 12 described later.

[0065] The target segment support structure 120 includes a stationary part notch 121, a support plate 122, a stationary part fixing screw 123, a height adjustment screw 124, and a support plate storage space 125.

[0066] The stationary part notch 121 is formed on the lower half horizontal joint surface 21, which is the upper surface of the lower half stationary part 20u of the stationary part 20. The stationary part notch 121 has an axial width that is arranged at a predetermined depth from the lower half horizontal joint surface 21 in the circumferential direction and outside the radial direction of the hook fitting annular groove 23 so that the support plate 122 can be accommodated.

[0067] The support plate 122 is a load transmission element that transmits the self-weight of the support target segment 30x to the lower half stationary part 20u. The support plate 122 is horizontally arranged in the stationary part notch 121 and fixed to the lower half stationary part 20u by the stationary part fixing screw 123.

[0068] On the other hand, a support plate storage space 125 capable of horizontally storing the support plate 122 is formed in the support target segment 30x among the packing ring segments 30a. The depth of the bottom surface of the support plate storage space 125 is formed to be the same as the height of the bottom surface of the stationary portion notch 121 formed in the stationary portion 20. Further, the height, that is, the circumferential width of the support plate storage space 125 is a dimension obtained by adding the thickness of the support plate 122 and the adjustment width in the height direction of the support target segment 30x, or a dimension with a further margin added thereto.

[0069] In the support target segment 30x, a female screw 124a that penetrates from the upper surface to the support plate storage space 125 and engages with the height adjustment screw 124 is further formed.

[0070] With the above configuration, the support target segment 30x and the height adjustment screw 124 are integrated, but the protruding length of the tip of the height adjustment screw 124 into the support plate storage space 125 changes due to the rotation of the height adjustment screw 124. Further, the support plate 122 is fixed to the lower half stationary portion 20u and is integrated with the lower half stationary portion 20u.

[0071] Next, as the operation of the present embodiment, the support function of the support target segment 30x by the target segment support structure 120, the adjustment function of the height position of the support target segment 30x, and these effects will be described.

[0072] <Support function of the support target segment 30x> With the above configuration, the tip (lower end) of the height adjustment screw 124 that is screwed into the support target segment 30x is in contact with the upper surface of the support plate 122 stored in the support plate storage space 125. Therefore, the support target segment 30x is prevented from moving vertically downward by the support plate 122. Also, the self-weight of the support target segment 30x, which is a vertically downward load, is transmitted to the upper surface of the support plate 122 via the height adjustment screw 124. Since the support plate 122 is fixed to the lower half stationary part 20u by the stationary part fixing screw 123, the downward load applied to the upper surface of the support plate 122 is transmitted to the lower half stationary part 20u. That is, the vertical load of the support target segment 30x is supported by the lower half stationary part 20u, and the support target segment 30x is constrained from being displaced in the vertical direction.

[0073] On the other hand, since only the tip (lower end) of the height adjustment screw 124 that is screwed into the support target segment 30x is in contact with the upper surface of the support plate 122 stored in the support plate storage space 125, the displacement in the horizontal direction is not constrained. As a result, the support target segment 30x is pressed radially inward by the spring force of the spring member 34s arranged between the support target segment 30x and the lower half stationary part 20u.

[0074] <Adjustment function of the height position of the support target segment 30x by the target segment support structure 120> As described above, the support target segment 30x is supported in the vertical direction by the height adjustment screw 124. As a result, the height position of the support target segment 30x is determined by the relative position with the height adjustment screw 124. Here, by turning the height adjustment screw 124, the screwing position between the support target segment 30x and the height adjustment screw 124 changes. That is, the protruding length of the height adjustment screw 124 into the support plate storage space 125 changes. Since the height position of the tip (lower end) of the height adjustment screw 124 is the height position in contact with the upper surface of the support plate 122, it does not change. Therefore, by changing the protruding length into the support plate storage space 125, the height position of the support target segment 30x changes.

[0075] <Effect of the second feature point> A description will be given with reference to FIG. 3. Now, assume a case where the target segment support structure 120 is not provided. In this case, consider a situation where after the rotating part 10 comes into contact and the lower half central segment 31 moves downward, the contact state is released. When the target segment support structure 120 is not provided, since the vertical movement of the lower half side segments 32 is not restricted, there is a possibility that the lower half side segments 32 on both sides, which are relatively higher in height position, will lean on the lower half central segment 31 from both sides of the lower half central segment 31.

[0076] In such a state, the ends of the lower half side segments 32 and the ends of the lower half central segment 31 may hit against each other, preventing smooth movement of each other, and there is a possibility that the lower half central segment 31 cannot return to its original position. As a result, the seal performance deteriorates, leading to a decrease in efficiency.

[0077] As a second feature point, when the target segment support structure 120 is provided, even when the contact state is released after the rotating part 10 comes into contact and the lower half central segment 31 moves downward, since the vertical movement of the lower half side segments 32 on both sides is restricted by the target segment support structure 120, the lower half central segment 31 can smoothly return to its original position.

[0078] FIG. 7 is a cross-sectional view showing the configuration of a modified example of the turbine shaft seal device 100 according to the first embodiment.

[0079] This modified example is an application example when the target segment support structure 120 is applied in a case where the packing ring 30 is divided into four packing ring segments 30a in the same manner as in the prior art.

[0080] As shown in Fig. 7, the packing ring 30 is composed of four circumferentially divided packing ring segments 30a. Specifically, it consists of two lower half segments 41 arranged below the horizontal dividing surface 20h of the stationary part 20 and two upper half segments 42 arranged above the horizontal dividing surface 20h of the stationary part 20. These four segments each have a circumferential angle of 90 degrees in the circumferential direction.

[0081] In each of the two lower half segments 41, a lower half spring 41s that biases the lower half segment 41 toward the rotation center axis CL is accommodated.

[0082] In each of the two upper half segments 42, an upper half spring 42s that biases the upper half segment 42 toward the rotation center axis CL is accommodated. Also, on the end face at the boundary between one upper half segment 42 and the other upper half segment 42, an upper half auxiliary spring 42j that acts in the direction of connecting the two upper half segments 42 is accommodated.

[0083] The biasing forces of the lower half spring 41s, the upper half spring 42s, and the upper half auxiliary spring 42j are set in the same manner as in the conventional example shown in Fig. 15, respectively.

[0084] In this way, even when the packing ring 30 is divided into four packing ring segments 30a as in the conventional case, the target segment support structure 120 can obtain the same effect as in the case of six - division, with the two lower half segments 41 as the target segments to be supported 30x. That is, when the rotating part 10 comes into contact with one or both of the two lower half segments 41 and then the contact state is released, since the upper end of the lower half segment 41 is supported by the target segment support structure 120, it does not move downward. Therefore, it does not move in the direction of the other lower half segment 41 and does not prevent its return to the original position.

[0085] In Fig. 7, the case where there are two lower half segments 41 is shown as an example, but the present invention is not limited to this. That is, if there are two or more lower half segments connected in the circumferential direction, two lower half segments adjacent to the lower half horizontal joint surface 21 among them can be similarly applied as the target lower half segments.

[0086] As described above, in the turbine shaft seal device 100 according to the present embodiment, as a first characteristic point, by dividing the packing ring 30 into six (three each in the upper and lower directions) packing ring segments 30a, when the rotating part 10 contacts the packing ring segment 30a below or above during operation, as a result of contacting only one packing ring segment 30a, the reaction force from the packing ring segment 30a can be suppressed to a low level, and local temperature rise of the rotating part 10 and vibration caused thereby can be suppressed.

[0087] Furthermore, as a second characteristic point, by providing the target segment support structure 120, even when the contact state is released after the rotating part 10 contacts and the lower half central segment 31 moves downward, since the vertical movement of the lower half side segments 32 on both sides is restricted by the target segment support structure 120, the lower half central segment 31 can smoothly return to its original position.

[0088] As described above, according to the present embodiment, it is possible to reduce the force received by the rotating part 10 when the rotating part 10 of the turbine contacts the packing ring segment 30a and suppress the shaft vibration of the rotating part 10. In particular, it can exhibit a great effect during the startup process and the stop process of the turbine.

[0089] [Second Embodiment] Fig. 8 is a partial horizontal cross-sectional view showing the configuration of the turbine shaft seal device 100a according to the second embodiment. Also, Fig. 9 is a partial vertical cross-sectional view taken along the line B-B of Fig. 8 showing the configuration of the turbine shaft seal device 100a according to the second embodiment.

[0090] This embodiment is a modification of the second feature point of the first embodiment. The turbine shaft seal device 100a has a target segment support structure 130 instead of the target segment support structure 120 in the embodiment. Hereinafter, the description of the common parts with the embodiment will be omitted, and the target segment support structure 130 will be described.

[0091] The target segment support structure 130 has a stationary part notch 131, a support plate 132, a segment fixing screw 133, and a height adjustment screw 134.

[0092] The stationary part notch 131 is formed on the lower half horizontal coupling surface 21 which is the upper surface of the lower half stationary part 20u of the stationary part 20. The stationary part notch 131 has an axial width that is arranged at a predetermined depth from the lower half horizontal coupling surface 21 in the circumferential direction and outside the radial direction of the hook fitting annular groove 23 and can accommodate the support plate 132.

[0093] The support plate 132 is the same as in the embodiment in that it is a load transmission element that transmits the self-weight of the support target segment 30x to the lower half stationary part 20u. The support plate 132 is horizontally arranged in the stationary part notch 131 and is coupled to the support target segment 30x by the segment fixing screw 133.

[0094] On the part of the support plate 132 mounted on the stationary part notch 131, a female thread 134a that engages with the height adjustment screw 134 is formed.

[0095] With the above configuration, the support target segment 30x and the segment fixing screw 133 are integrated. By rotating the height adjustment screw 134, the protruding length of the tip of the height adjustment screw 134 to the bottom surface of the stationary part notch 131 changes.

[0096] Next, as the operation of this embodiment, the support function of the support target segment 30x by the target segment support structure 130, the adjustment function of the height position of the support target segment 30x, and these effects will be described.

[0097] <Support function for the supported segment 30x> With the above configuration, the tip (lower end) of the height adjustment screw 134 that is screwed into the support plate 132, which is integral with the supported segment 30x, is in contact with the bottom surface of the stationary part notch 131. Therefore, the downward movement of the supported segment 30x in the vertical direction is blocked by the height adjustment screw 134. Also, the self-weight of the supported segment 30x, which is a vertically downward load, is transmitted to the height adjustment screw 134 via the segment fixing screw 133 and the support plate 132. The downward load transmitted to the height adjustment screw 134 is transmitted to the bottom surface of the stationary part notch 131, that is, the lower half stationary part 20u. That is, the vertical load of the supported segment 30x is supported by the lower half stationary part 20u, and the displacement of the supported segment 30x in the vertical direction is restricted.

[0098] On the other hand, since only the tip (lower end) of the height adjustment screw 134 that is screwed into the support plate 132 is in contact with the bottom surface of the stationary part notch 131, the displacement in the horizontal direction is not restricted. As a result, the supported segment 30x is pressed radially inward by the spring force of the spring member 34s disposed between the supported segment 30x and the lower half stationary part 20u as in the embodiment.

[0099] <Function for adjusting the height position of the supported segment 30x by the target segment support structure 130> As described above, the supported segment 30x is supported in the vertical direction by the height adjustment screw 134. As a result, the height position of the supported segment 30x is determined by the relative position with the height adjustment screw 134. Here, by turning the height adjustment screw 134, the screwed position of the support plate 132 and the height adjustment screw 134 changes. That is, the protruding length of the height adjustment screw 134 to the bottom surface of the stationary part notch 131 changes. Since the height position of the tip (lower end) of the height adjustment screw 134 is the depth position of the bottom surface of the stationary part notch 131, it does not change. Therefore, by changing the protruding length to the bottom surface of the stationary part notch 131, the height position of the supported segment 30x changes.

[0100] <Effect> As described above, the target segment support structure 130 in the present embodiment can constrain the support target segment 30x in the vertical direction and adjust the vertical direction of the constraint position, and has the same effect as the target segment support structure 120 in the first embodiment.

[0101] [Third Embodiment] FIG. 10 is a partial horizontal cross-sectional view showing the configuration of the turbine shaft seal device 100b according to the third embodiment. FIG. 11 is a partial vertical cross-sectional view taken along the C-C arrow in FIG. 10 showing the configuration of the turbine shaft seal device 100b according to the third embodiment.

[0102] This embodiment is a modification of the second feature point of the first embodiment. The turbine shaft seal device 100b has a target segment support structure 140 instead of the target segment support structure 120 in the embodiment. Hereinafter, the description of the common part with the embodiment is omitted, and the target segment support structure 140 will be described.

[0103] The target segment support structure 140 has a stationary part notch 141, a segment extension plate part 142, and a height adjustment screw 144.

[0104] The stationary part notch 141 is formed on the lower half horizontal joint surface 21 which is the upper surface of the lower half stationary part 20u of the stationary part 20. The stationary part notch 141 is arranged at a predetermined depth from the lower half horizontal joint surface 21 in the circumferential direction and on the radially outer side of the hook fitting annular groove 23 in the radial direction, and has the same axial width as the axial width of the hook fitting annular groove 23.

[0105] The support target segment 30x of the present embodiment has a segment extension plate part 142 whose uppermost part extends radially outward. The segment extension plate part 142 may be attached to the support target segment 30x by, for example, welding, or may be integrally manufactured and processed as a part of the support target segment 30x. The segment extension plate part 142 is mounted on the bottom surface of the stationary part notch 141. A female screw 144a that engages with the height adjustment screw 144 is formed on the segment extension plate part 142.

[0106] With the above configuration, as the height adjustment screw 144 rotates, the protruding length of the tip of the height adjustment screw 144 to the bottom surface of the stationary part notch 141 changes.

[0107] Next, as the operation of this embodiment, the support function of the support target segment 30x by the target segment support structure 140, the adjustment function of the height position of the support target segment 30x, and these effects will be described.

[0108] With the above configuration, the tip (lower end) of the height adjustment screw 144 that is screwed with the segment extension plate portion 142, which is a part of the support target segment 30x, is in contact with the bottom surface of the stationary part notch 141. Therefore, also in this embodiment, the support target segment 30x is prevented from moving vertically downward by the height adjustment screw 144 and is constrained from displacing in the vertical direction, and the vertical load of the support target segment 30x is supported by the lower half stationary part 20u. Also, similar to the first embodiment, the spring force of the spring member 34s disposed between the support target segment 30x and the lower half stationary part 20u presses it inward in the radial direction. Further, similar to the embodiment, as the protruding length to the bottom surface of the stationary part notch 141 changes, the height position of the support target segment 30x will change.

[0109] <Effect> As described above, the target segment support structure 140 in this embodiment can constrain the support target segment 30x in the vertical direction and adjust the vertical direction of the constraint position, and has the same effect as the target segment support structure 120 in the first embodiment.

[0110] Furthermore, in this embodiment, since the segment extension plate portion 142 is integral with the support target segment 30x, members for connection such as the stationary part fixing screw 123 of the embodiment or the segment fixing screw 133 of the second embodiment are not required.

[0111] [Fourth Embodiment] FIG. 12 is a partial horizontal cross-sectional view showing the configuration of the turbine shaft seal device 100c according to the fourth embodiment. FIG. 13 is a partial vertical cross-sectional view taken along the line D-D of FIG. 12 showing the configuration of the turbine shaft seal device 100c according to the fourth embodiment.

[0112] This embodiment is a modification of the second feature point of the first embodiment. The turbine shaft seal device 100c has a target segment support structure 150 instead of the target segment support structure 120 in the embodiment. Hereinafter, the description of the common parts with the embodiment will be omitted, and the target segment support structure 150 will be described.

[0113] The target segment support structure 150 has a support rod storage groove 151, a support rod 152, and a height adjustment screw 154. In this embodiment, the stationary part inner support rod storage hole 153 is formed in the lower half stationary part 20u instead of the stationary part notch 121 in the embodiment in order to support the support rod 152 that is horizontal in the circumferential direction. The support rod storage groove 151 is formed such that the support rod 152 penetrates through the support target segment 30x horizontally without contacting it. Specifically, the support rod storage groove 151 extends in the circumferential direction and expands radially outward within the support target segment 30x.

[0114] On the upper part of the support rod storage groove 151 of the support target segment 30x, in the portion radially above the support rod 152, a female thread 154a that engages with the height adjustment screw 154 in the vertical direction is formed.

[0115] With the above configuration, the height adjustment screw 154 is integrated with the support target segment 30x. The tip of the height adjustment screw 154 integrated with the support target segment 30x contacts the upper side surface of the support rod 152, and the self-weight of the support target segment 30x is transmitted to the support rod 152 and supported by the lower half stationary part 20u.

[0116] Similar to the first embodiment, when the protruding length of the adjustment screw 154 toward the support rod 152 changes, the height position of the support target segment 30x changes.

[0117] <Effect> As described above, the target segment support structure 150 in the present embodiment can constrain the support target segment 30x in the vertical direction and adjust the vertical position of the constraint position, and has the same effect as the target segment support structure 120 in the first embodiment.

[0118] According to the embodiment described above, it is possible to provide a turbine shaft seal device that can reduce the force received by the rotating part when the rotating part of the turbine contacts the packing ring segment and suppress the shaft vibration of the rotating part.

[0119] [Other Embodiments] The embodiments of the present invention have been described above. However, the embodiments are presented as examples and are not intended to limit the scope of the invention. Also, the features of each embodiment may be combined. Furthermore, the embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. The embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0120] 1... Turbine, 2... Main flow path, 3... Leakage flow path, 3a... First leakage flow path, 3b... Second leakage flow path, 10... Rotating part, 10a... Outer peripheral surface, 11... Rotor, 12... Moving blade row, 20... Stationary part, 20a... Inner peripheral surface, 20h... Horizontal dividing surface, 20u... Lower half stationary part, 20v... Upper half stationary part, 21... Lower half horizontal joint surface, 22... Upper half horizontal joint surface, 23... Hook fitting annular groove, 24... Protrusion on the front side of the annular groove, 24a... Outer peripheral surface of the front side protrusion, 25... Protrusion on the rear side of the annular groove, 25a... Outer peripheral surface of the rear side protrusion, 28... Static blade row, 30... Packing ring, 30a... Packing ring segment, 30u... Lower half of the packing ring, 30v... Upper half of the packing ring, 30x... Supported segment, 31... Lower half central segment, 31s... Lower half central spring, 32... Lower half side segment (target lower half segment), 32s... Lower half side spring, 33... Upper half central segment, 34... Upper half side segment, 34s... Upper half side spring, 34j... Upper half side auxiliary spring, 35... Inner peripheral ring part, 36... Front hook, 36a... Inner peripheral surface of the front hook, 37... Rear hook, 37a... Inner peripheral surface of the rear hook, 38... Seal fin, 39... Outer peripheral ring part, 40... Support key, 41... Lower half segment, 41s... Lower half spring, 42... Upper half segment, 42j... Upper half auxiliary spring, 42s... Upper half spring, 50a... Packing ring segment, 51... Lower half segment, 51s... Lower half spring, 52... Upper half segment, 52a... Spring hole, 52s... Upper half spring, 52j... Upper half auxiliary spring, 100, 100a, 100b, 100c... Turbine shaft seal device, 120... Supported segment support structure, 121... Notch in the stationary part, 122... Support plate, 123... Screw for fixing the stationary part, 124... Height adjustment screw, 124a... Female screw, 125... Storage space for the support plate, 130... Supported segment support structure, 131... Notch in the stationary part, 132... Support plate, 133... Screw for fixing the segment, 134... Height adjustment screw, 134a... Female screw, 140... Supported segment support structure, 141... Notch in the stationary part, 142... Segment extension plate part, 144... Height adjustment screw, 144a... Female screw, 150... Supported segment support structure, 151... Support rod storage groove, 152... Support rod, 153... Inner support rod storage hole in the stationary part, 154... Height adjustment screw, 154a... Female screw, CL... Rotation center axis

Claims

1. A turbine shaft seal device for suppressing leakage of the working fluid from between a lower stationary portion and an upper stationary portion that are arranged to annularly surround a rotating portion of a turbine that rotates around a rotation center axis by the working fluid and are in close contact with each other vertically on respective horizontal joint surfaces, and the rotating portion, comprising: a packing ring lower half portion and a packing ring upper half portion that constitute an annular packing ring having an inner peripheral ring portion to which a hook that fits into a hook fitting annular groove formed in the circumferential direction in the lower stationary portion and the upper stationary portion and at least one seal fin protruding toward the surface of the rotating portion and formed in the circumferential direction are attached; the packing ring lower half portion is statically supported by the lower stationary portion; a lower central segment arranged at the center in the circumferential direction of the lower half; two lower side segments on both sides in the circumferential direction of the lower central segment, one circumferential end of each of which faces the circumferential end of the lower central segment; and having; the packing ring upper half portion is statically supported by the upper stationary portion; an upper central segment arranged at the center in the circumferential direction of the upper half; two upper side segments on both sides in the circumferential direction of the upper central segment, one circumferential end of each of which faces the circumferential end of the upper central segment and the other end of which is supported by a support plate provided on the horizontal joint surface of the upper stationary portion; and having; the turbine shaft seal device further comprises: lower central biasing means for biasing the lower central segment inward in the radial direction; lower side biasing means for biasing each of the two lower side segments inward in the radial direction; upper side biasing means for biasing each of the two upper side segments inward in the radial direction; two upper central biasing means provided between the upper central segment and each of the two upper side segments and biasing the upper central segment in a direction to bring the upper central segment into close contact with each of the two upper side segments; and comprising; A turbine shaft seal device characterized by the above.

2. The biasing force for the lower central segment is greater than the weight of the lower central segment by a predetermined first minute value; The biasing forces of the two upper central biasing means for the upper central segment are smaller than the force for separating the upper central segment and the two upper side segments by a predetermined second minute value. The turbine shaft seal device according to claim 1, characterized in that...

3. In a cross section perpendicular to the rotation center axis, the circumferential angle between both ends in the circumferential direction of the lower half central segment is such that even when the rotating part contacts the central part in the circumferential direction of the lower half central segment and the lower half central segment moves radially outward, the rotating part does not contact the lower half side segment. The turbine shaft seal device according to claim 1, characterized in that...

4. In a cross section perpendicular to the rotation center axis, the circumferential angle between both ends in the circumferential direction of the upper half central segment is such that even when the rotating part contacts the central part in the circumferential direction of the upper half central segment and the upper half central segment moves radially outward, the rotating part does not contact the upper half side segment. The turbine shaft seal device according to claim 1, characterized in that...

5. A turbine shaft seal device for suppressing leakage of working fluid between a rotating part that rotates around a rotation center axis in a turbine and an upper half stationary part and a lower half stationary part that are arranged so as to annularly surround the rotating part and are in close contact with each other on their respective horizontal joint surfaces, Each has a hook that fits into a hook fitting annular groove formed in the circumferential direction in the lower half stationary part and an inner circumferential ring part to which at least one seal fin protruding toward the outer surface of the rotating part and formed in the circumferential direction is attached. Among a plurality of lower half segments connected in the circumferential direction, it has a target segment support structure that supports each of the two target lower half segments adjacent to the horizontal joint surface. The target segment support structure has a height adjustment part capable of adjusting the vertical relative position between the lower half stationary part and the target lower half segment. The turbine shaft seal device, characterized in that...

6. The turbine shaft seal device according to any one of claims 1 to 4, wherein each of the two lower half side segments is provided between the lower half stationary part and the lower half side segment as a target lower half segment and supports the lower half side segment, and has a target segment support structure having a height adjustment part capable of adjusting the vertical relative position between the lower half stationary part and the lower half side segment. Or, the turbine shaft seal device according to claim 5, whichever is the case, The lower half stationary part has a stationary part notch formed on its upper end surface. The target lower segment has a flange formed on its upper end surface, The target segment support structure, has a support plate housed within the stationary portion notch and horizontally fixed to the lower stationary portion, The height adjustment portion has an adjustment screw that engages with the flange formed on the target lower segment and can bear the self-weight of the target lower segment, The target lower segment has a receiving hole formed horizontally from the side surface for housing the support plate, The support plate is housed in the receiving hole, The tip of the flange can press the upper surface of the support plate, A turbine shaft sealing device characterized by this.

7. A turbine shaft sealing device according to any one of Claims 1 to 4, wherein each of the two lower side segments, as a target lower segment, is provided between the lower stationary portion to support the lower side segment and has a target segment support structure with a height adjustment portion capable of adjusting the vertical relative position between the lower stationary portion and the lower side segment. Or, the turbine shaft sealing device according to Claim 5, whichever is applicable, The lower stationary portion has a stationary portion notch formed on its upper end surface, The target lower segment has a flange formed on its upper end surface, The target segment support structure, has a support plate housed within the stationary portion notch, horizontally fixed to the lower stationary portion, and having a flange formed thereon, The height adjustment portion has an adjustment screw that engages with the flange formed on the support plate and can bear the self-weight of the target lower segment, The tip of the flange can press the upper surface of the stationary portion notch, A turbine shaft sealing device characterized by this.

8. A turbine shaft sealing device according to any one of Claims 1 to 4, wherein each of the two lower side segments, as a target lower segment, is provided between the lower stationary portion to support the lower side segment and has a target segment support structure with a height adjustment portion capable of adjusting the vertical relative position between the lower stationary portion and the lower side segment. Or, the turbine shaft sealing device according to Claim 5, whichever is applicable, The lower stationary portion has a stationary portion notch formed on its upper end surface, The target lower segment has a protruding portion housed within the stationary portion notch and having a flange formed thereon, The target segment support structure is, The height adjustment part is screwed with the male thread formed on the protruding part, and has an adjustment screw capable of bearing the self-weight of the target lower half segment, The tip of the male thread can press the upper surface of the stationary part notch, A turbine shaft seal device characterized by this.

9. A turbine shaft seal device according to any one of Claims 1 to 4, wherein each of the two lower half side segments is provided as a target lower half segment between the lower stationary part and supports the lower half side segment, and has a target segment support structure having a height adjustment part capable of adjusting the vertical relative position between the lower stationary part and the lower half side segment. A turbine shaft seal device, Or, the turbine shaft seal device according to Claim 5, Whichever is, Further having a support rod horizontally supported by the lower stationary part, The target lower half segment has a support rod storage groove formed horizontally from the side surface and a male thread formed so as to penetrate vertically from the upper end surface to the support rod storage groove, The height adjustment part is screwed with the male thread formed on the target lower half segment, and has an adjustment screw capable of bearing the self-weight of the target lower half segment, The tip of the male thread can press the upper surface of the support rod, A turbine shaft seal device characterized by this.

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