JP6877962B2 - Manufacturing method of steam turbine partition plate, steam turbine and steam turbine partition plate - Google Patents

Description

The present invention relates to a steam turbine partition plate, a steam turbine, and a method for manufacturing a steam turbine partition plate.

In the steam turbine, stationary blades and moving blades are alternately installed in a plurality of stages in an internal passage through which steam passes. The rotor blades are integral with the rotor shaft and receive steam pressure to rotate the rotor shaft. A partition plate with a stationary blade that acts as a nozzle is installed between the moving blades. The partition plate is a partition plate except for the part where the stationary blades are installed, and the airtightness between the moving blades is maintained. As shown in FIGS. 4 and 5, the partition plate 51 includes an outer ring 52 which is a ring-shaped plate-shaped member fixed to the passenger compartment and an inner ring 54 which is a ring-shaped plate-shaped member installed on the rotor shaft side. A stationary blade 53 or the like installed between the inner peripheral end of the outer ring 52 and the outer peripheral end of the inner ring 54 is provided.

Patent Document 1 below discloses a technique in which an inner ring and a stationary blade, and an outer ring and a stationary blade are fitted to each other to form a partition plate, and a welding step and an annealing step are omitted. According to Patent Document 2 below, when the stationary blades are fitted and assembled without welding, the load applied to the stationary blades becomes larger in the vicinity of the joint surface of the inner ring or the outer ring divided into upper and lower parts as compared with other parts. A technique for suppressing the edge effect is disclosed. Patent Document 3 below discloses a technique for preventing the inner ring from collapsing by connecting the upper and lower divided inner rings constituting the 360 ° inner ring.

Japanese Patent No. 4131739 Japanese Patent No. 4072177 Japanese Unexamined Patent Publication No. 2004-176548

As shown in FIG. 4, conventionally, welding is performed between the inner ring 54 and the stationary blade 53 and between the outer ring 52 and the stationary blade 53 in a ring shape over the entire circumference, so that it is often used in the welding process and the annealing process. It took a lot of work time. The welded portion is, for example, a portion indicated by reference numeral M in FIG. Further, in some steam turbines used for thermal power generation, welding work is reduced or omitted by fitting. For example, as shown in FIG. 5, a holding plate 61 may be used to fit the stationary blade 53 between the outer ring 52 and the inner ring 54 and fix it so as not to move. The pressing plate 61 is fixed to the inner ring 54 side by a bolt 65, and has a shape protruding in the radial direction from the inner ring 54 side to the stationary blade 53 side. The protruding portion 62 of the pressing plate 61 is locked with the recess 64 formed in the stationary blade 53, and the movement of the stationary blade 53 in the circumferential direction is restricted.

As shown in FIG. 5, in the partition plate 51, the thickness of the inner ring 54, that is, the length L _{6 in} the steam flow direction is longer than _{the length L 5} in the steam flow direction of the blade 53b of the stationary blade 53. As a result, the rigidity of the inner ring 54 of the partition plate 51 can be increased, and deformation due to steam pressure can be suppressed. For example, to the steam flow direction of the length L ₅ of the wing 53b of the stationary blade 53, the steam flow direction length L ₆ of the inner ring 54 is longer. Stationary blade 53, in order to effectively inject steam against blades 5 of the downstream side, the wing 53b of the stationary blade 53, of the upstream portion of the vapor stream direction of the length L ₄ of the stationary blade 53 It is provided from approximately the center to the downstream end.

On the other hand, as shown in FIG. 5, in the inner shroud 53a which is a joint portion of the stationary blade 53 to be joined to the inner ring 54, when the holding plate 61 is installed on the upstream side of the partition plate 51, the stationary blade is installed. On the upstream side of the 53 in the steam flow direction, it is necessary to form a recess 64 that can be locked with the protruding portion 62 of the holding plate 61. Therefore, the stationary blade 53 is provided with a stepped portion between the blade 53b and the inner shroud 53a that recedes to the downstream side in the steam flow direction, and the blade 53b is an inner on the outer peripheral side (lower side of the paper surface in FIG. 5). The shroud 53a has a shape protruding to the upstream side of the steam flow.

Thus, the stationary blade 53, blade 53b has with respect to the vicinity of the center of the steam flow direction being formed in a length L ₅ only on the downstream side, the inner shroud 53a of the stationary blade 53, an inner ring 54 bonding lengths of when bonding is the same as the vapor flow direction length L ₆ of the inner ring 54. That is, the inner shroud 53a is formed with a _{length L 6} from the upstream end side to the downstream end side in the steam flow direction. Therefore, when such a stationary blade 53 is manufactured by machining, it is more than the blade 53b as shown _{by the hatched portion (the portion corresponding to the difference between the length L 6} and the length L _{5) by the broken line in FIG.} Since it is necessary to perform processing to remove the portion on the upstream side in the steam flow direction, an extra cutting allowance is provided. Therefore, there is a problem that wasteful material costs and work man-hours are generated.

Further, in a steam turbine used for geothermal power generation, geothermal steam is supplied to the steam turbine, and the steam turbine is driven by geothermal steam. At this time, the scale S contained in the geothermal steam may be accumulated around a small step groove formed by the holding plate 61 and the bolt 65 installed on the upstream side, and the stationary blade 53 is blocked. It may be one of the factors that cause or corrode.

The present invention has been made in view of such circumstances, and reduces an extra cutting allowance when the inner ring and the stationary blade are joined without welding and the stationary blade is manufactured by cutting. It is an object of the present invention to provide a steam turbine partition plate, a steam turbine, and a method for manufacturing a steam turbine partition plate, which are possible.

In order to solve the above problems, the following means are adopted in the method for manufacturing the steam turbine partition plate, the steam turbine and the steam turbine partition plate of the present invention.
That is, the steam turbine partition plate according to the present invention is a plate-shaped member fixed to the passenger compartment, and is installed on the rotor shaft side with a plurality of outer ring members arranged in the circumferential direction to form a ring-shaped outer ring. A wing is formed by being supported between a plurality of inner ring members which are plate-shaped members and are arranged in the circumferential direction to form a ring-shaped inner ring, an inner peripheral end portion of the outer ring, and an outer peripheral end portion of the inner ring. A plurality of holding plates installed on a surface of the inner ring member on the downstream side in the steam flow direction and having protrusions protruding from the inner ring member toward the stationary wing member, and the stationary wing member. The joint portion formed in a concave shape on the surface on the downstream side in the steam flow direction, provided with the protrusion and the recess for locking, and joined with the inner ring member formed on the stationary blade member is the length in the steam flow direction. The inner ring member is shorter than the length in the steam flow direction.

According to this configuration, a protrusion protruding from the inner ring member to the stationary blade member is installed on the surface of the inner ring member on the downstream side in the steam flow direction, and the protruding portion of the holding plate is the steam flow in the stationary blade member. It locks with a concave recess formed on the surface on the downstream side in the direction. As a result, the protruding portion is locked with the concave portion, and the movement of the stationary blade member in the circumferential direction is restricted. Further, the stationary blade member is formed with a joint portion to be joined to the inner ring member, and the length of the joint portion in the stationary blade member in the steam flow direction is shorter than the length of the inner ring member in the steam flow direction. Since the inner ring member and the stationary blade member are locked to each other by the protruding portion and the concave portion on the radial surface intersecting the steam flow direction on the downstream side in the steam flow direction, the steam at the joint portion in the stationary blade member. The upstream end in the flow direction is located downstream of the upstream end in the steam flow direction of the inner ring member. Therefore, the length of the joint portion in the stationary blade member can be shortened as compared with the case where the inner ring member and the stationary blade member are locked to each other on the surface on the upstream side in the steam flow direction. As a result, when forming the stationary blade member including the blade, it is possible to reduce the extra cutting allowance caused by the difference between the length of the joint portion in the steam flow direction and the length of the stationary blade member. In addition, since the protrusions and recesses are located on the downstream side in the steam flow direction, the scale starts from a small step groove formed by a holding plate or a bolt as compared with the case where the protrusion and the recess are located on the upstream side in the steam flow direction. Is hard to adhere.

In the above invention, the length of the inner ring member in the steam flow direction may be 1.5 to 2.5 times the length of the joint portion in the steam flow direction.

In the above invention, a plurality of the projecting portions are installed on the inner ring member along the circumferential direction of the inner ring, and a plurality of groove portions correspond to the positions where the plurality of pressing plates are installed. The plurality of recesses may be formed in the stationary wing member corresponding to the positions where the plurality of protrusions are installed.

According to this configuration, since a plurality of recesses of the protrusion and the joint of the presser plate are installed along the circumferential direction of the inner ring, the inner ring member and the stationary blade member are securely fixed, and the circumference of the stationary blade member is peripherally fixed. Directional movement is further constrained.

In the above invention, the stationary blade member is provided with a step portion between the end surface of the joint portion and the inner peripheral end surface of the inner ring with respect to the upstream side in the steam flow direction on the inner peripheral side of the blade, and the inner ring is provided. The inner peripheral end surface of the above may have a shape protruding toward the upstream side in the steam flow direction.

The steam turbine partition according to any one of claims 1 to 4, wherein the steam turbine according to the present invention includes a rotor shaft, a moving blade installed on the rotor shaft, and a steam turbine partition installed adjacent to the moving blade. It is equipped with a board.

In the above invention, it is desirable that the steam turbine partition plate is installed in the impulse stage.

In the above invention, the steam turbine may be supplied with geothermal steam and may be driven by steam containing at least a part of the geothermal steam.

The method for manufacturing a steam turbine partition plate according to the present invention is a plate-shaped member fixed to the passenger compartment, and is installed on a rotor shaft side with a plurality of outer ring members arranged in the circumferential direction to form a ring-shaped outer ring. A wing is formed by being supported between a plurality of inner ring members which are plate-shaped members and are arranged in the circumferential direction to form a ring-shaped inner ring, an inner peripheral end portion of the outer ring, and an outer peripheral end portion of the inner ring. The joint portion provided with the stationary blade member and joined with the inner ring member formed on the stationary blade member has a length in the steam flow direction shorter than the length in the steam flow direction of the inner ring member. A method for manufacturing a steam turbine partition plate, which is characterized in that a plurality of holding plates having protrusions protruding from the inner ring member toward the stationary blade member are provided on a surface of the inner ring member on the downstream side in the steam flow direction. It includes a step of installing in the formed groove and a step of locking the protruding portion with respect to the concave portion formed in a concave shape on the surface of the stationary blade member on the downstream side in the steam flow direction.

According to the present invention, when the inner ring and the stationary blade are joined without being welded, an extra cutting allowance can be reduced when the stationary blade is manufactured by cutting.

It is a vertical sectional view which shows the partition plate, the moving blade and the rotor shaft of the steam turbine which concerns on one Embodiment of this invention. It is a perspective view which shows the partition plate part of the steam turbine which concerns on one Embodiment of this invention. It is a perspective view which shows the holding plate of the steam turbine which concerns on one Embodiment of this invention. It is a vertical cross-sectional view which shows an example of the partition plate of the conventional steam turbine. It is a vertical sectional view which shows another example of the partition plate of the conventional steam turbine.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
In the steam turbine according to the embodiment of the present invention, as shown in FIG. 1, the stationary blades (static blade members) 3 and the moving blades 5 alternate in the axial direction of the rotor shaft 6 in the internal passage 10 through which steam passes. It is installed in multiple stages. Each rotor blade 5 is integrated with the rotor shaft 6 and receives the flow and pressure of steam to rotate the rotor shaft 6. A steam turbine partition plate 1 on which a stationary blade 3 on which a plurality of blades 3b are arranged is installed is installed between the moving blades 5 and the moving blades 5. Each of the plurality of steam turbine partition plates 1 is a partition wall except for a portion where a plurality of stationary blades 3 are installed, and airtightness between the moving blades 5 is maintained.
The steam applied to this embodiment is steam containing at least a part of steam and geothermal steam, but may be medium steam of a low boiling medium in an organic Rankine cycle (ORC) power generation system.

The steam turbine partition plate 1 includes an outer ring 2 which is a ring-shaped plate-shaped member fixed to the passenger compartment 7, an inner ring 4 which is a ring-shaped plate-shaped member installed on the rotor shaft 6 side, and an inner ring 2. A stationary blade 3 or the like installed between the peripheral end portion and the outer peripheral end portion of the inner ring 4 is provided. The steam turbine partition plate 1 according to the present embodiment is installed, for example, in the impulse stage of the steam turbine.

In the steam turbine partition plate 1, the rotor shaft 6 is incorporated on the inner peripheral side of the inner ring 4. Therefore, in consideration of workability during assembly and overhaul, the steam turbine partition plate 1 has a half ring (180 degree ring) shape divided into upper and lower parts in the present embodiment, and the outer ring 2 and the inner ring 4 are each formed. It is divided into two parts.

In the following, as shown in FIG. 2, a semi-ring-shaped member having a circumferential direction of 180 °, which constitutes the steam turbine partition plate 1 in which the steam turbine partition plate 1 is divided, is referred to as a partition plate portion 1A. Further, a semi-ring-shaped member having a circumferential direction of 180 ° constituting the outer ring 2 in which the outer ring 2 is divided is referred to as a divided outer ring 2A (or an outer ring member), and the circumference forming the inner ring 4 in which the inner ring 4 is divided is referred to. A semi-ring-shaped member having a direction of 180 ° is called a split inner ring 4A (or inner ring member).

When assembling the steam turbine partition plate 1, the outer shroud 3c of the stationary blade 3 is arranged in the groove 2a at the inner peripheral end of one of the divided outer rings 2A. Further, the inner shroud (joint portion) 3a of the stationary blade 3 is arranged on the convex protrusion 4a at the outer peripheral end of one of the divided inner rings 4A. Then, a plurality of stationary blades 3 are sequentially arranged to form one partition plate portion 1A. Similarly, the stationary blades 3 are sequentially arranged at the inner peripheral end portion of the other split outer ring 2A and the outer peripheral end portion of the other split inner ring 4A to form the other partition plate portion 1A.

After that, the outer peripheral end of the split outer ring 2A of one of the partition plate portions 1A is fixed to the inner wall surface of the vehicle interior 7, and then the rotor shaft 6 is arranged at the inner peripheral end of the split inner ring 4A. Then, the other partition plate portion 1A is arranged so that the inner peripheral end portion of the divided inner ring 4A of the other partition plate portion 1A corresponds to the rotor shaft 6, and the outer circumference of the divided outer ring of the other partition plate portion 1A is arranged. The end is fixed to the inner wall of the passenger compartment 7. That is, the steam turbine partition plate 1 is assembled with the two split outer rings 2A and the two split inner rings 4A sandwiching the stationary blade 3.

In FIG. 2, only the partition plate portion 1A, which is the lower half portion of the steam turbine partition plate 1, is shown, and the partition plate portion 1A, which is the lower half portion, is the partition plate portion (the upper half portion). (Not shown) is placed.

As shown in FIG. 2, a groove portion 2a is formed at the inner peripheral end portion of the divided outer ring 2A along the central portion thereof. That is, a concave groove portion 2a extending radially outward is formed at the inner peripheral end portion of the divided outer ring 2A along the peripheral surface thereof. On the other hand, a protrusion 4a is formed along the central portion of the outer peripheral end of the divided inner ring 4A. That is, a convex protrusion 4a extending radially outward is formed at the outer peripheral end of the divided inner ring 4A along the peripheral surface thereof. Although not shown, the partition plate portion of the upper half is similarly formed with a groove portion at the inner peripheral end portion of the split outer ring 2A and a protrusion portion at the outer peripheral end portion of the split inner ring. When the lower half partition plate portion 1A and the upper half partition plate portion are connected, the groove portions 2a of the split outer ring 2A are continuous, and the protrusions 4a of the split inner ring 4A are continuous. ..

A stationary blade 3 is arranged between the split outer ring 2A and the split inner ring 4A. That is, a plurality of stationary blades 3 are arranged along the circumferential direction. The stationary wing 3 has an inner shroud 3a, a wing 3b, and an outer shroud 3c, and the wing 3b is sandwiched between the inner shroud 3a and the outer shroud 3c. When a steam flow occurs, the gap formed between the two adjacent blades 3b functions as a nozzle for ejecting steam toward the moving blade 5.

At the inner peripheral end of the inner shroud 3a, a fitting groove 3d that fits into the protrusion 4a of the split inner ring 4A is formed along the inner peripheral end thereof, and at the outer peripheral end of the outer shroud 3c, the split outer ring is formed. A fitting protrusion 3e that fits into the groove portion 2a of 2A is formed along the outer peripheral end portion thereof.
Further, the flat surface 4b of the divided inner ring 4A is connected to the flat portion of the upper half of the divided inner ring.

The inner shroud 3a formed on the stationary blade 3 according to the present embodiment is joined to the inner ring 4. On the surface 4c on the downstream side of the steam flow in the inner ring 4, holding plates 11 having protrusions 12 protruding in the radial direction from the inner ring 4 to the stationary blade 3 are installed at a plurality of places. The protruding portion 12 is locked with the recess 14 formed on the surface 3f on the downstream side in the steam flow direction in the inner shroud 3a of the stationary blade 3. A plurality of pressing plates 11 are arranged in the circumferential direction. In the present embodiment, for example, three locations are arranged on the semi-ring-shaped divided inner ring 4A for 180 ° in the circumferential direction, but the number is not limited to this, and the size of the inner ring 4 and the size of the stationary blade 3 are appropriately selected. Will be done. By locking the protruding portion 12 of the pressing plate 11 with the recess 14, the movement of the stationary blade 3 in the circumferential direction with respect to the split inner ring 4A is restricted.

Further, as shown in FIG. 1, since the presser plate 11 is formed on the surface 3f on the downstream side in the steam flow direction, the presser plate 11 with respect to the upstream end surface 3g located on the upstream side in the steam flow direction. It is not necessary to consider the locking with the protruding portion 12. Therefore, with respect to the split inner ring 4A, the upstream end face 3g of the inner shroud 3a in the blade 3b of the stationary blade 3 in the steam flow direction is located on the downstream side of the upstream end face 4d of the split inner ring 4A in the steam flow direction. Can be done.

Thus, the inner shroud 53a of the inner ring 54 and the stationary blade 53 as shown in FIG. 5, the steam flow direction of the upstream side surface 54a, as compared with the case to be locked to each other at 53c, the inner shroud 3a length L ₁ Can be shortened. As a result, with respect to the inner shroud 3a including the blade 3b, the upstream end surface 4d located on the upstream side of the split inner ring 4A in contact with the inner shroud 3a in the steam flow direction has a shape protruding toward the upstream side in the steam flow direction. ..

_{The length L 1} of the inner shroud 3a in the steam flow direction _{is shorter than the length L 3} of the inner ring 4 in the steam flow direction, and is substantially the same _{as the length L 2} of the blade 3b of the stationary blade 3 in the steam flow direction. Therefore, when manufacturing by machining machined stator vanes 3 is less wasteful cutting margin caused by the difference in length L ₁ of the length L ₁ and wings 3b of the steam flow direction of the inner shroud 3a. _{The length L 3} of the inner ring 4 in the steam flow direction is, for example, 1.5 times _{the length L 1} of the inner shroud 3a of the stationary blade 3 _{and the length L 2 of the} blade 3b in the steam flow direction. It is 2.5 times. As a result, the rigidity of the inner ring 4 of the steam turbine partition plate 1 can be increased, and deformation due to steam pressure can be suppressed.

When assembling the steam turbine partition plate 1 as described above, for example, the split outer ring 2A is fixed to the inner wall surface of the vehicle interior 7. At the time of this fixing, a joint portion (not shown) is formed on the inner wall surface of the passenger compartment 7 and the outer peripheral end portion of the split outer ring 2A, and the split outer ring 2A is formed inside the passenger compartment 7 by these joint portions. Fix it to the wall. After that, the fitting projection 3e formed on the outer shroud 3c of the stationary blade 3 is fitted to the groove portion 2a formed along the inner peripheral end portion of the split outer ring 2A, and the inner peripheral end of the split outer ring 2A is fitted. The stationary blade 3 is arranged along the portion. Further, the protrusion 4a formed on the divided inner ring 4A is fitted into the fitting groove 3d formed on the inner shroud 3a of the stationary blade 3 and arranged. The fitting protrusions 3e of the outer shrouds 3c of the plurality of stationary blades 3 are sequentially arranged by being fitted to the divided outer ring 2A, and the inner of the stationary blade 3 is formed on the protrusions 4a formed on the divided inner ring 4A. It is fitted and arranged in the fitting groove 3d formed in the shroud 3a.

After forming the partition plate portion 1A in this way, the rotor shaft 6 of the steam turbine is arranged at the inner peripheral end portion of the divided inner ring 4A via a seal member (not shown). After that, the lower half of the split inner ring 4A and the upper half of the split inner ring are connected. At this time, the rotor shaft 6 on which the moving blades 5 are arranged is arranged at the inner peripheral end portion of the upper half of the divided inner ring.

On the other hand, the same is performed for the split inner ring of the upper half, and the fitting formed on the inner shroud 3a of the stationary blade 3 with respect to the protrusion 4a formed on the outer peripheral end of the split inner ring 4A of the upper half. It is fitted into the joint groove 3d. Further, the groove portion 2a formed along the inner peripheral end portion of the upper half of the split outer ring 2A is fitted into the fitting projection 3e formed on the outer shroud 3c of the stationary blade 3. As a result, the partition plate portion of the upper half is formed. As a result, the steam turbine partition plate 1 is assembled.

Further, in the present embodiment, on the surface 4c on the downstream side of the steam flow of the inner ring 4 and the surface 3f on the downstream side of the steam flow of the stationary blade 3, a plurality of pressing plates 11 are installed on the inner peripheral end portion of the outer ring 2. A plurality of stationary blades 3 are arranged in a row in the circumferential direction between the outer peripheral ends of the inner ring 4. By locking the protruding portion 12 of the pressing plate 11 with the recess 14 formed in the stationary blade 3, the movement of the stationary blade 3 in the circumferential direction is restricted. Similarly, in the partition plate portion 1A of the upper half, the split inner ring 4A and the stationary blade 3 are provided with a holding plate 11 in addition to the fitting of the protrusion 4a and the fitting groove 3d of the inner shroud 3a. The protrusion 12 and the recess 14 are locked. As a result, when the partition plate portion 1A is lifted during assembly or overhaul, it also contributes to prevent the split inner ring 4A from being displaced or dropped.

As shown in FIG. 1, the pressing plate 11 is a plate-shaped member, and is fixed to the inner ring 4 by, for example, a bolt 15. The inner ring 4 is formed with a concave groove portion 13 from the inner peripheral end portion toward the outer circumference on the surface 4c side on the downstream side of the steam flow, and the pressing plate 11 is installed in the groove portion 13. The depth of the groove portion 13 is substantially the same as the thickness of the holding plate 11. As a result, when the pressing plate 11 is installed in the groove portion 13, the surface 4c of the inner ring 4 and the outer surface of the pressing plate 11 become substantially the same surface.

As shown in FIG. 3, the presser plate 11 is formed with a through hole 16 in a direction parallel to the plate thickness direction, and a bolt 15 can be inserted into the through hole 16. In the present embodiment, two through holes 16 are formed in one presser plate 11, and the presser plate 11 is fixed to the inner ring 4 (divided inner ring 4A) with two bolts 15, whereby the presser plate 11 is formed. The position can be securely fixed by preventing the rotation of itself. On the surface 4c of the inner ring 4, a through hole 17 is formed in the groove portion 13 corresponding to the fixing position of the two bolts 15, and a screw groove is formed in the through hole 17.

Further, the stationary blade 3 at the position where the pressing plate 11 is arranged has a concave recess 14 formed on the surface 3f side on the downstream side in the steam flow direction, and the protruding portion 12 of the pressing plate 11 is the recess 14. It is installed inside. The depth of the recess 14 is substantially the same as the thickness of the holding plate 11. As a result, when the protruding portion 12 of the pressing plate 11 is installed in the recess 14, the surface 3f on the downstream side in the steam flow direction and the outer surface of the pressing plate 11 become substantially the same surface.

The protruding portion 12 formed on one end side of the presser plate 11 is arranged so as to face the outer peripheral side which is opposite to the side fixed to the inner ring 4. When the pressing plate 11 is fixed to the inner ring 4, the projecting portion 12 projects from the inner ring 4 toward the stationary blade 3. The side surface of the protruding portion 12 comes into contact with the inner wall surface of the recess 14 formed in the stationary blade 3, and the protruding portion 12 locks with the recess 14.

It is not necessary to install one pressing plate 11 for each of the stationary blades 3, and as shown in FIG. 2, the pressing plates 11 are arranged with a plurality of stationary blades 3 sandwiched between them. In the present embodiment, for example, three locations are arranged on the divided inner ring 4A. A plurality of pressing plates 11 are installed on the inner ring 4 along the circumferential direction of the inner ring 4. A plurality of recesses 14 are formed in the stationary blade 3 corresponding to the positions where the plurality of holding plates 11 are installed. As a result, a plurality of pressing plates 11 and recesses 14 having the protrusions 12 are installed along the circumferential direction of the inner ring 4, so that the inner ring 4 and the stationary blade 3 are securely fixed, and the stationary blade 3 is in the circumferential direction. Movement is further constrained.

As a procedure for installing the pressing plate 11, first, the stationary blade 3 is fixedly arranged at the inner peripheral end of the outer ring 2, the outer peripheral end of the inner ring 4 is fixed to the stationary blade 3, and then the pressing plate 11 is installed in the groove 13. To install. At this time, the protruding portion 12 of the holding plate 11 is fitted into the recess 14 formed in the stationary blade 3.

Then, the bolt 15 is inserted into the through hole 16 and screwed into the through hole 17 of the inner ring 4, and the holding plate 11 is fixed to the inner ring 4. As a result, the protruding portion 12 is locked with the recess 14 of the stationary blade 3 in a state where the protruding portion 12 protrudes in the radial direction from the inner ring 4 side.

As described above, according to the present embodiment, the following effects can be obtained.
On the surface 4c on the downstream side in the steam flow direction of the inner ring 4, a pressing plate 11 having a protrusion 12 formed with a protrusion 12 protruding in the radial direction from the inner ring 4 to the stationary blade 3 is installed, and the protruding portion 12 is a stationary blade. It locks with the recess 14 formed on the surface 3f on the downstream side in the steam flow direction in 3. As a result, the protruding portion 12 is locked with the recess 14, and the movement of the stationary blade 3 in the circumferential direction is restricted.

Further, the stationary blade 3, which is the inner shroud 3a is formed to be bonded to the inner ring 4, the inner shroud 3a in the stationary blade 3, the length L ₁ is the vapor flow direction, the length of the steam flow direction of the inner ring 4 shorter than L _3. This does not need to dispose the holding plate 11 on the surface 4c on the downstream side in the steam flow direction of the inner ring 4 and on the upstream end surface 4d located on the upstream side in the steam flow direction. Therefore, on the upstream side of the steam flow, the stationary blade 3 is provided with a stepped portion between the blade 3b, the inner shroud 3a, and the inner ring 4 in contact with the inner shroud 3a. The stepped portion has a shape in which the upstream end surface 4d located on the upstream side of the inner ring 4 in the steam flow direction protrudes to the upstream side of the steam flow with respect to the inner shroud 3a on the inner peripheral side of the blade 3b. The inner ring 4 and the stationary blade 3 are locked to each other by the protrusion 12 and the recess 14 on the surfaces 4c and 3f on the downstream side in the steam flow direction. As shown in FIG. 1, the upstream end surface 3g of the inner shroud 3a in the stationary blade 3 in the steam flow direction is located on the downstream side of the upstream end surface 4d located on the upstream side in the steam flow direction of the inner ring 4.

Therefore, as shown in FIG. 5, in the present embodiment, the inner ring 54 and the stationary blade 53 are stationary as compared with the case where the inner ring 54 and the stationary blade 53 are locked to each other by the pressing plate 61 on the surfaces 54a and 53c on the upstream side in the steam flow direction. it is possible to shorten the length L ₁ of the inner shroud 3a in the blade 3. As a result, it is possible to reduce the extra cutting allowance generated when the stationary blade 3 including the blade 3b is manufactured by cutting. Further, since the protrusion 12 and the recess 14 of the presser plate 11 are located on the downstream side in the steam flow direction, as shown in FIG. 5, the presser plate 61 is installed on the upstream side as compared with the case where the presser plate 61 is installed on the upstream side. The scale does not easily adhere to the periphery of 11. In particular, when the steam turbine according to the present embodiment is applied to a steam turbine used for geothermal power generation, geothermal steam is supplied to the steam turbine, and the steam turbine is driven by geothermal steam. At this time, it becomes difficult for the scale to adhere to the surroundings starting from the small step groove formed by the pressing plate 11 and the bolt 15, and it is possible to prevent the stationary blade 3 from being blocked or corroded.

1: Steam turbine partition plate 1A: Partition plate part 2: Outer ring 2A: Divided outer ring (outer ring member)
2a: Groove 3: Static blade (static blade member)
3a: Inner shroud (joint)
3b: Wing 3c: Outer shroud 3d: Fitting groove 3e: Fitting protrusion 3f: Surface 3g: Upstream end surface 4: Inner ring 4A: Divided inner ring (inner ring member)
4a: Protrusion 4b: Flat surface 4c: Surface 4d: Upstream end surface 5: Moving blade 6: Rotor shaft 7: Vehicle interior 10: Internal passage 11: Holding plate 12: Projection 13: Groove 14: Recess 15: Bolt 16 : Through hole 17: Through hole 51: Partition plate 52: Outer ring 53: Static blade 53a: Inner shroud 53b: Blade 53c: Surface 54: Inner ring 54a: Surface 61: Pressing plate 62: Protruding portion 64: Recessed portion 65: Bolt

Claims (8)

A plurality of outer ring members that are plate-shaped members fixed to the passenger compartment and are arranged in the circumferential direction to form a ring-shaped outer ring.
A plate-shaped member installed on the rotor shaft side, and a plurality of inner ring members arranged in the circumferential direction to form a ring-shaped inner ring.
A stationary blade member supported between the inner peripheral end of the outer ring and the outer peripheral end of the inner ring to form a wing.
A plurality of pressing plates installed on the surface of the inner ring member on the downstream side in the steam flow direction and having protrusions protruding from the inner ring member toward the stationary blade member.
A recess formed in a concave shape on the surface of the stationary blade member on the downstream side in the steam flow direction and engaging with the protrusion,
With
The joint portion formed on the stationary blade member and joined to the inner ring member is a steam turbine partition plate characterized in that the length in the steam flow direction is shorter than the length in the steam flow direction of the inner ring member. The steam turbine partition plate according to claim 1, wherein the length of the inner ring member in the steam flow direction is 1.5 to 2.5 times the length of the joint portion in the steam flow direction. A plurality of the protruding portions are installed on the inner ring member along the circumferential direction of the inner ring.
A plurality of grooves are formed in the inner ring member corresponding to the positions where the plurality of holding plates are installed.
The steam turbine partition plate according to claim 1 or 2, wherein the plurality of recesses are formed in the vane member corresponding to the positions where the plurality of protrusions are installed. The stationary blade member is provided with a step portion between the end surface of the joint portion and the inner peripheral end surface of the inner ring with respect to the upstream side in the steam flow direction on the inner peripheral side of the blade, and the inner circumference of the inner ring is provided. The steam turbine partition plate according to any one of claims 1 to 3, wherein the end face has a shape protruding upstream in the steam flow direction. With the rotor shaft
The rotor blades installed on the rotor shaft and
The steam turbine partition plate according to any one of claims 1 to 4, which is installed adjacent to the rotor blade.
A steam turbine equipped with. The steam turbine according to claim 5, wherein the steam turbine partition plate is installed in an impulse stage. The steam turbine according to claim 5 or 6, wherein geothermal steam is supplied and driven by steam containing at least a part of the geothermal steam. A plate-shaped member fixed to the passenger compartment, a plurality of outer ring members arranged in the circumferential direction to form a ring-shaped outer ring, and a plate-shaped member installed on the rotor shaft side, arranged in the circumferential direction. The stationary wing member includes a plurality of inner ring members forming a ring-shaped inner ring, a stationary wing member supported between the inner peripheral end portion of the outer ring and the outer peripheral end portion of the inner ring, and a wing is formed. The joint portion to be joined to the inner ring member formed in is a method for manufacturing a steam turbine partition plate, characterized in that the length in the steam flow direction is shorter than the length in the steam flow direction of the inner ring member. ,
A step of installing a plurality of holding plates having protrusions protruding from the inner ring member toward the stationary blade member in a groove formed on a surface of the inner ring member on the downstream side in the steam flow direction.
A step of locking the protruding portion with respect to a concave portion formed in a concave shape on a surface of the stationary blade member on the downstream side in the steam flow direction.
A method of manufacturing a steam turbine partition plate comprising.

Images