JP2014167277A - Method for removing internal stress of caulking portion of turbin rotor blade planting part, and caulking portion heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To release a caulked state of a caulking portion of a turbin rotor blade planting part.SOLUTION: A heating coil 42 is disposed facedly to a caulking portion 12a of a side surface of a turbin wheel 10. During the time that the heating coil 42 is relatively rotated in an axial direction of a turbin rotor 1 so as to sequentially move a location of the caulking portion 12a to which the heating coil 42 faces, a high frequency current is supplied to the heating coil 42 so as to subject the caulked portion 12a to induction heating at the location to face. The caulking portion 12a to be separated from the location to face to the heating coil 42 after the heating is then subjected to slow cooling.

Description

  The present invention relates to a method of heating the caulking part to remove the internal stress and an apparatus for heating the caulking part in order to cancel the caulking state of the caulking part of the turbine rotor blade implantation part.

  The turbine rotor of the power generation turbine has a structure in which a plurality of blades (blades) are fitted and attached along the outer peripheral edge of the turbine wheel. One structure of a blade implantation part that fits and attaches blades to the outer peripheral edge of a turbine wheel is shown in FIG. 2 called a tangential entry type (tangential insertion dovetail structure). This wing implantation part is configured as follows. At the outer peripheral edge of the turbine wheel 10, the fitting portions 12 made of ridges and ridges are formed along the circumferential direction on both sides. On the other hand, a base portion 14a of the blade 14 is formed in a bowl shape, and a fitting portion 18 composed of a concave stripe and a convex stripe that fits in the fitting section 12 of the turbine wheel 10 is formed on the inner peripheral surface of the bowl shaped base portion 14a. Form. The blade-shaped base portion 14 a of the blade 14 is extended from the notch portion 20 (the portion where the fitting portion 12 is not formed) formed in one place in the circumferential direction of the turbine wheel 10 to the outer peripheral edge portion of the turbine wheel 10. It is inserted and slid in the circumferential direction as it is, and the fitting parts 12 and 18 are fitted together. Similarly, the bases 14 a of the individual blades 14 are sequentially inserted from the notches 20 and are slid in the circumferential direction, thereby arranging the blades on the entire circumference of the turbine wheel 10. The last one blade 14 ′ (stop blade) is not formed with a portion corresponding to the fitting portion 18 of the other blade 14, and is disposed as it is in the notch portion 20. A stop key 22 is inserted into each of four holes formed by the base portion 14a 'of the stop blade 14' and its adjacent base portions 14a, and grooves 21 formed in the adjacent surfaces of the adjacent base portions 14a. Is prevented from coming out of the notch 20. The fitting portion 12 of the turbine wheel 10 is formed with a portion 12a that sandwiches both lower end portions 14aa of the base portion 14a of the blade 14 from the outside. After attaching all the blades 14 to the turbine wheel 10, as shown in FIG. By caulking the portion 12a inward over the circumference (plastic deformation by roll caulking), the fitting between the fitting portions 12 and 18 is strengthened and the blades 14 are fixed to the turbine wheel 10.

  The turbine has a service life, and the steam turbine that has passed the service life is dismantled. The turbine rotor taken out from the steam turbine has a turbine blade outer diameter (outer diameter including blades 14) of about 4.5 meters in the case of a low-pressure steam turbine. Difficult to carry out outdoors. For this reason, it is necessary to remove the blades 14 from the turbine wheel 10 to reduce the outer diameter of the turbine rotor. Further, when the turbine rotor is disassembled and recycled, the blades 14 need to be removed from the turbine wheel 10. However, as shown in FIG. 3, when the caulking portion 12 a has a strong caulking structure, the blades 14 cannot be slid in the circumferential direction and cannot be extracted through the notch portion 20. Further, the caulking portion 12a is solid and cannot be caulked using a tool to be released. Therefore, the present applicant has previously proposed a method and an apparatus for cutting a caulking portion of a turbine rotor blade implantation portion and releasing the caulking state in Patent Document 1 below.

JP 2010-269433 A

  The present invention is intended to provide a method for releasing the caulking state of the caulking portion of the turbine rotor blade implantation portion by a method different from the method proposed by Patent Document 1 and an apparatus usable for the method.

  In the present invention, the caulking portion is heated by dielectric heating to remove the internal stress, and the caulking state of the caulking portion is released. That is, in the caulking portion internal stress removal method according to the present invention, the heating coil is disposed so as to face the caulking portion on the side surface of the turbine wheel, and the heating coil is rotated relative to the direction of the axis of the turbine rotor. While sequentially moving the position of the caulking portion facing each other, a high frequency current is supplied to the heating coil to inductively heat the caulking portion at the facing position, and after the heating, away from the facing position with the heating coil By gradually cooling the crimped portion, the internal stress of the crimped portion is removed. According to this, by arranging the heating coil facing the caulking portion on the side surface of the turbine wheel, rotating the heating coil relative to the direction around the axis of the turbine rotor, and sequentially heating and gradually cooling the caulking portion, The caulking state can be sequentially released by sequentially removing the internal stress of the caulking portion by annealing.

  In the caulking portion internal stress removal method of the present invention, the relative rotation of the heating coil in the direction around the axis of the turbine rotor, for example, stops the rotation of the turbine rotor in the direction around the axis and rotates the heating coil in the direction around the axis. Can be done. The relative rotation of the heating coil in the direction around the axis of the turbine rotor can also be performed by stopping the rotation of the heating coil in the direction around the axis and rotating the turbine rotor in the direction around the axis.

  The heating device according to the present invention includes a roller support frame supported by a foundation, a plurality of support rollers rotatably supported by the roller support frame in a direction around the axis, and a direction around the axis by the plurality of support rollers. A ring that is rotatably mounted and supported; a ring rotation drive mechanism that rotationally drives the ring in an axial direction; a heating coil that is mounted on the ring; and a power supply device that supplies a high-frequency current to the heating coil. The ring is arranged coaxially with respect to the turbine rotor supported by the foundation, and the heating coil is arranged to face the caulking part and induction heats the caulking part at the facing position. is there. According to this, by rotating the ring mounted and supported on the plurality of support rollers by the ring rotation driving mechanism, the heating coil moves along the caulking portion, and the caulking portion can be heated sequentially. The caulking portion that has passed through the heating portion is gradually cooled, so that the internal stress is removed and the caulking state is released.

  In the heating device of the present invention, the roller support frame may be supported by the rail so as to be movable along a rail supported by the foundation in parallel with the axis of the turbine rotor. According to this, it can move to the turbine wheel position of each stage, and can heat a caulking part.

  In the heating device of the present invention, the heating coil may be mounted on the ring so as to be movable in the radial direction of the turbine rotor. According to this, according to the radial direction position of the caulking part which changes with the stage of a turbine wheel, a heating coil can be moved to radial direction and it can face a caulking part.

  In the heating device according to the present invention, the heating coil is mounted on the ring via a coil mounting member, the coil mounting member mounts a guide roller in addition to the heating coil, and the coil mounting member is interposed between the coil mounting member and the ring. A coil mounting member moving mechanism for moving the coil mounting member in a direction in which the coil mounting member is moved toward and away from the surface to which the side surface of the turbine wheel belongs with respect to the ring so that the guide roller contacts the side surface of the turbine wheel. The guide roller is rotated by the rotation of the ring while being in contact with the side surface of the turbine wheel by the coil mounting member moving mechanism, and the guide roller and the side surface of the turbine wheel are in contact with each other. By contact, the clearance between the side surface of the turbine wheel and the heating coil shall be maintained at a predetermined value. It can be. According to this, the crimping part can be sequentially and stably heated in a state where the clearance between the side surface of the turbine wheel and the heating coil is kept at a predetermined value.

  In the heating device of the present invention, the heating coil is mounted on the ring via an arm-shaped coil mounting member, and one end of the arm-shaped coil mounting member is rotatably connected to the ring. The coil mounting member can be pivoted about the one end and connected to the ring so as to be retractable to the outside of the ring. According to this, when the arm-shaped coil mounting member is moved to the turbine wheel position of each stage by swinging the arm-shaped coil mounting member around one end and swinging it out of the ring, the arm-shaped coil mounting member is The wheel can be removed.

  In the heating device of the present invention, the ring may be divided at a plurality of locations in the circumferential direction so as to be reassembled. According to this, it is possible to divide the ring and carry it to a site where heating is performed, and to assemble and use it on the site. Even if the turbine rotor is supported on the floor with both ends in the axial direction on the support base, a ring is assembled inside the two support bases and the heating device is arranged at the position of the turbine wheel at a predetermined stage. be able to.

  In the heating device according to the present invention, the driving mechanism transmits a driving force to the ring via at least one of the plurality of support rollers to rotate the ring in the direction around the axis. be able to. According to this, the ring can be rotated by driving the support roller.

It is a front view which shows embodiment of the heating apparatus by this invention. It is a perspective view which shows a tangential entry type wing implantation part structure. It is sectional drawing which shows a mode that the wing implantation part of FIG. 2 is caulked from both sides of a turbine rotor. It is a perspective view of the heating apparatus of FIG. It is a perspective view which shows the state which has arrange | positioned the heating apparatus of FIG. 1 in the position which performs the first stress removal process of a turbine rotor. It is a perspective view which shows the structure of the ring 30 of FIG. It is a figure which shows the storage state of the turbine rotor 1 removed from the steam turbine, (a) is a side view, (b) is a perspective view. It is a perspective view which shows the structure of the roller frame 36 and the rail 38 of FIG. FIG. 9 is a front view showing a positional relationship between a lower portion of the roller frame 36 and rails 38 in FIG. 8. It is sectional drawing which shows the internal structure of the support roller 34 of FIG. It is a perspective view which shows the structure of the ring rotation drive mechanism 72 which rotationally drives the ring 30 of FIG. It is a figure which shows the system configuration | structure of the induction heating apparatus 41 of FIG. It is a perspective view which shows the structure of the coil arm 40 and the coil moving mechanism 37 of FIG. It is a front view which shows a mode that the heating coil 42 moves by the coil moving mechanism 37 of FIG. FIG. 14 is a view showing the operation of the guide roller 98 of FIG. 13, and is a view seen from the front of the guide roller 98. It is a perspective view which shows the moving mechanism 117a of the one end side (attachment pin 119 side of the coil arm 40) among the moving mechanisms 117 of the coil arm 40 of FIG. It is a perspective view which shows the moving mechanism 117b of the other end side (arm fixing bolt 121 side of the coil arm 40) among the moving mechanisms 117 of the coil arm 40 of FIG. It is a side view of the moving mechanism 117b of FIG. FIG. 4 is a perspective view showing a configuration of a roller frame moving mechanism 139 that moves the roller frame 36 of FIG. 1 along a rail 38. FIG. 4 is a front view showing a state in which the coil arm 40 is retracted to the outside of the turbine blade outer diameter when the roller frame 36 is moved along the rail 38. It is a front view which shows the mode of the movement of the heating coil 42 accompanying rotation of the ring 30 at the time of the heating of the crimping | crimped part 12a.

  Embodiments of the present invention will be described below. FIG. 1 shows the overall configuration of a heating device 11 according to the present invention. FIG. 4 is a perspective view thereof. FIG. 5 shows a heating device for the turbine rotor 1 that is removed from the steam turbine and supported and stored on support stands (temporary stand) 54, 54 installed on the floor 52 of the temporary place in the power plant building. 11 shows a state in which 11 is arranged. The heating device 11 includes a ring 30, four support rollers 34, a roller frame (roller support frame) 36, a rail 38, a coil arm (coil mounting member) 40, a coil moving mechanism 37 (FIG. 13), and a coil arm moving mechanism 117. (FIG. 16, FIG. 17, FIG. 18), induction heating device (heating coil 42, high-frequency current transformer 44, feeder 46, high-frequency inverter 48, cooling water circulation unit 50, etc.) 41, ring rotation drive mechanism for rotating the ring 30 72 (FIG. 11), a roller frame moving mechanism 139 (FIG. 19) for moving the roller frame 36 along the rail 38, a control panel 51 (FIG. 4), and the like. The rail 38 is laid on a floor (foundation) 52 in parallel with the axis A of the turbine rotor 1 (FIG. 5). The roller frame 36 is supported by the rail 38 so as to be movable along the rail 38 (FIG. 8). The four support rollers 34 are attached to and supported by a roller frame 36 so as to be rotatable around a rotation axis parallel to the turbine rotor axis A (FIG. 4). A ring 30 is placed and supported on the four support rollers 34 so as to be rotatable around a rotation axis parallel to the turbine rotor axis A. One or more of the four support rollers 34 are driven to rotate by a driving device to form a driving roller (the others are driven rollers), and the ring 30 is driven by the rotation of the driving roller 34. Rotate around. A heating coil (induction coil) 42 is mounted on the ring 30 via a coil arm 40. The heating coil 42 is disposed to face the crimping portion 12a (FIGS. 2 and 3) of the turbine wheel 10. By supplying a high-frequency current from the high-frequency inverter 48 to the heating coil 42 via the feeder 46 and the high-frequency current transformer 44, the caulking portion 12 a is induction-heated at a position facing the heating coil 42. By rotating the ring 30 at a constant low speed, the heating coil 42 relatively moves along the crimping portion 12a. During the relative movement, the caulking portion 12a is heated at a position facing the heating coil 42, and is gradually cooled by moving away from the facing position with the heating coil 42 after the heating. The internal stress of 12a is removed and the caulking state is released.

The components of the heating device 11 will be described.
<< Ring 30 >>
The structure of the ring 30 is shown in FIG. If the inner diameter of the ring 30 is configured to be larger than the outer diameter of the turbine blade 10 of the turbine wheel 10 to be heated, after the heat treatment for one stage of the turbine wheel 10 is finished, the ring 30 is not disassembled, The heat treatment can be performed by moving to the position of the turbine wheel 10 of the stage. If the outer diameter of the turbine wheel 10 is large, the diameter of the ring 30 also becomes large. Therefore, it is desirable that the ring 30 bends a plate steel material and combines it by welding to ensure an H section or the like to ensure strength. Of course, the present invention is not limited to this, and the ring 30 may be formed of a steel material having a square pipe-like cross section or a round pipe-like cross section. In most cases, the turbine rotor 1 removed from the steam turbine is supported and stored on the support bases 54 and 54 installed on the floor 52 of the temporary place in the power plant building as shown in FIG. . In order to arrange the heating device 11 in the stored state with respect to the turbine rotor 1, the ring 30 can be divided into a plurality of parts, and the ring 30 is formed by assembling them at the site. Is desirable. Further, since the turbine rotor 1 is supported on the floor 52 by the support bases 54 and 54, and the ring 30 cannot pass through the support bases 54 and 54, the ring 30 needs to be divided from this point. Therefore, the ring 30 is divided into parts, and the ring 30 is assembled and used so as to be wound around the turbine rotor 1 in the vicinity of the axial central portion of the turbine rotor 1. After use, the ring 30 is disassembled at the same position to disassemble the turbine rotor 1. Remove from the position. In this embodiment, as shown in FIG. 6, the two rings 30-1 and 30-2 constituting the ring 30 are divided into four equal parts in the circumferential direction and divided into eight members 30 a to 30 g. The ring 30 is formed by connecting 30 g with the connecting fittings 54 and 56, the connecting pipe 58, and bolts and nuts for connecting them. Note that the inner diameter of the ring 30 does not necessarily have to be greater than the maximum diameter of the turbine blade outer diameter of the turbine wheel 10 (the outer diameter of the turbine blade 10 at the outermost position). It only needs to be larger than the outer diameter of the turbine blade. A pair of guide brackets 125 and 133 to which the coil arm 40 is attached are fixed to the rings 30 to the left and right rings 30-1 and 30-2, respectively.

<Roller frame 36, rail 38>
The configuration of the roller frame 36 and the rail 38 is shown in FIG. The roller frame 36 is made of H steel, which is highly available here, and is combined to form a truss structure that is advantageous in terms of strength. The roller frame 36 bears the weight of the ring 30 via the four support rollers 34. Here, four sets (36a, 36b, 36c, 36d) of the roller frame 36 are independently manufactured for each support roller 34 with a welded structure, and these four left and right connecting members 60 (the roller frames 36a, 36b are connected to each other, the roller frame 36c). , 36d are connected to each other) and the six front / rear connecting members 62 (the roller frames 36a, 36c are connected to each other and the roller frames 36b, 36d are connected to each other) and the bolts and nuts are detachably connected to each other. Is configured. The positions and lengths of the connecting members 60 and 62 are set so as to prevent unintended deformation and breakage of the roller frame 36 due to the weight of the ring 30. In addition, the roller frame 36 may be configured as an assembly type by dividing each member in consideration of the portability at the time of installation as in this example, or may be configured as an integral structure by welding. The arrangement relationship between the lower part of the roller frame 36 and the rail 38 is shown in FIG. A caster 64 is mounted on the lower surface of the roller frame 36 so that the roller frame 36 can be moved in the axial direction of the turbine rotor 1. Four rails 38 (38a, 38b, 38c, 38d) made of C-shaped steel are provided on the surface of the floor 52 in parallel with the turbine rotor axis A and with respect to the turbine rotor axis A when viewed from the plane in order to guide the casters 64. The two are fixedly laid at left and right symmetrical positions. The caster 64 is accommodated in the recess 39 of the rail 38 and can run along the rail 38. Instead of the combination of the C-shaped steel rail 38 and the caster 64, a combination of a rail for rail and an iron wheel used in a factory yard or a railway can be used. Each rail 38 has a structure in which a plurality of rails 38 are divided into a plurality of pieces in the longitudinal direction and are combined at the site in consideration of transportability and installation at the site.

<Supporting roller 34>
The configuration of the support roller 34 installed on the roller frame 36 is shown in FIG. The support roller 34 includes a rotating shaft 66 that forms a central axis, a roller body 68 that is fixed to the rotating shaft 66 and rotates together with the rotating shaft 66, and left and right bearing blocks that bear the load of the ring 30 that is applied via the rotating shaft 66. 70, 70. The roller body 68 is composed of metal wheels, and receives and supports the ring 30 on the outer peripheral surface 68a. The support roller 34 is supported by the roller frame 36 via bearing blocks 70 and 70 so as to be rotatable integrally with the rotary shaft 66. Of course, the present invention is not limited to this. For example, the roller body 68 is rotatable with respect to the shaft 66 by incorporating a bearing in the roller body 68 (the shaft 66 is fixed to the roller frame 36 so as not to rotate). The structure may be changed as long as the support roller 34 can support the weight of the ring 30 as a whole and the roller body 68 can rotate. A flange 68b for preventing the ring 30 from coming off is formed on the outer end surfaces of the roller bodies 68 facing each other with the ring 30 in the width direction (thickness direction).

<< Ring rotation drive mechanism 72 >>
FIG. 11 shows the configuration of a ring rotation drive mechanism 72 that rotates the ring 30. The ring rotation drive mechanism 72 transmits the rotational force from the drive motor 74 via the drive sprocket 76, the intermediate chain 78, the intermediate sprocket 80, the intermediate shaft 82, the intermediate sprocket 84, the drive chain 86, the roller sprocket 88, and the roller drive shaft 90. The ring 30 is transmitted to one support roller 34 (drive roller 34a) and the ring 30 is rotationally driven by the rotational force of the drive roller 34a. The ring 30 is rotated at a constant low speed. The rotational speed of the caulking portion 12a is different for each turbine wheel 10 so that the linear velocity at the radial position becomes equal according to the radial position of the caulking portion 12a whose radial position varies depending on the turbine wheel 10. It is set according to the position. The contact surface between the roller main body 68 and the ring 30 of the drive roller 34a (the outer peripheral surface 68a of the roller main body 68 and the outer peripheral surface 30i of the ring 30) is formed to have a surface roughness that does not slip even when the drive roller 34a is driven. Yes. The drive motor 74 is attached to and supported by the roller frame 36, and the intermediate sprockets 80 and 84 are coaxially connected to each other by an intermediate shaft 82. The intermediate shaft 82 is supported by the roller frame 36 by bearings 92 and 94, and the roller drive shaft 90 Is coaxially connected to the rotating shaft 66 (FIG. 10) of the driving roller 34a (or formed as an integral part of the rotating shaft 66 of the driving roller 34a). The drive mechanism for rotating the ring 30 is not limited to the configuration shown in FIG. 11, and the drive roller 34a may be directly driven by the motor, for example, by appropriately selecting a drive motor with a gear head. In this embodiment, one of the four support rollers 34 is driven by one motor 74 as a drive roller, but instead of the four support rollers 34 The plurality of support rollers can be driven in common or individually by one or a plurality of motors. Instead of driving the ring 30 with the support roller 34, a ring dedicated to driving may be provided separately from the support roller 34, or a drive mechanism other than the roller may be provided to rotationally drive the ring 30.

<< Induction heating device 41 >>
As the induction heating device 41, a commercially available general device can be used. The system configuration of the induction heating device 41 is shown in FIG. The induction heating device 41 includes a high frequency inverter (high frequency power source) 48, a high frequency current transformer (transformer) 44, a heating coil 42, and a cooling water circulation unit 50. A feeder 46 connecting the high frequency inverter 48 and the high frequency current transformer 44 is for high frequency current. Electric wires and cooling water pipes are passed inside. The heating unit 43 in which the high-frequency current transformer 44 and the heating coil 42 are combined is brought close to the crimping portion 12 a of the turbine wheel 10, and the crimping portion 12 a is heated by the heating coil 42. The high frequency inverter 48 and the cooling water circulation unit 50 are arranged on the floor 52 on the side of the turbine wheel 10 close to the heating unit 43, and the high frequency current transformer 44 and the high frequency are fed by a feeder 46 including a high frequency current wire and a cooling water pipe. The inverter 48 and the cooling water circulation unit 50 are connected and used.

<< Coil Arm 40 and Coil Moving Mechanism 37 >>
The configuration of the coil arm 40 and the coil moving mechanism 37 is shown in FIG. The coil arm 40 is formed in an L shape by connecting two long and short pieces 40a, 40b made of steel or the like at right angles, and the heating unit 43 (the high-frequency current transformer 44 and the heating coil 42) is connected via a coil mounting plate 96. Mount. Since the gaps between the stages of the turbine wheel 10 are narrow and the blades 14 protrude greatly, the heating coil 42 can be arranged in the vicinity of the caulking portion 12a of the turbine wheel 10 using such a configuration. The coil arm (coil mounting member) 40 can be configured with a cantilever support structure instead of the two-point support as shown in FIG. 13 if a strength problem is solved and a fixing structure is provided instead. The coil arm 40 is mounted with a configuration capable of adjusting the radial position of the heating coil 42 with respect to the turbine wheel 10. Since the radial position of the crimping portion 12a of the turbine wheel 10 is slightly different depending on each stage, the heating coil 42 faces the crimping section 12a of each stage by making the radial position of the heating coil 42 adjustable. Can be positioned. In FIG. 13, a feed screw 98 and a shaft 100 are disposed on the long piece 40a of the coil arm 40 along the extending direction thereof. The feed screw 98 is manually rotated by a handle 102 attached to the upper end. A feed screw nut 104 is screwed onto the feed screw 98, and a slide block 106 is slidably attached to the shaft 100 along the shaft 100. The slide block 106 and the feed screw nut 104 are connected to each other by an intermediate plate 108. Therefore, when the feed screw 98 is rotated, the intermediate plate 108 moves along the long piece 40a without rotation. The long piece 40a is provided with shafts 111 and 113 along positions where the feed screw 98 and the shaft 100 are extended downward. Slide blocks 107 and 108 are slidably mounted on the shafts 111 and 113 along the shaft 100, respectively. The slide blocks 107 and 108 are connected to each other by a coil mounting plate 96. The intermediate plate 108 and the coil mounting plate 96 are connected to each other by a connecting rod 115. The coil attachment plate 96 is equipped with a heating unit 43 in which the high-frequency current transformer 44 and the heating coil 42 are combined. The coil moving mechanism 37 is configured as described above, whereby when the operator manually rotates the handle 102, the intermediate plate 108 moves along the long piece 40a, and the movement of the intermediate plate 108 is performed via the connecting rod 115. It is transmitted to the coil mounting plate 96, and the heating unit 43 moves along the long piece 40a without rotation. In this way, the heating coil 42 can be moved in the moving direction including the radial component of the turbine wheel 10. FIG. 14 shows how the heating coil 42 moves. The heating coil 42 is moved to an optimum position for heating the caulking part 12a by moving the position of the heating coil 42 even with respect to the turbine wheel at different stages where the caulking part 12a exists at different radial positions r1 and r2. It is possible to make it.

<< Coil arm moving mechanism 117 >>
A guide roller 98 is mounted on the coil arm 40 as shown in FIG. The coil arm moving mechanism 117 moves the coil arm 40 toward and away from the ring 30 with respect to the heating surface of the turbine wheel 10 (the surface heated by the heating coil 42), and the guide roller 98 is moved to FIG. As shown, the heating surface of the turbine wheel 10 is kept pressed against the unheated position, thereby maintaining the clearance d between the heating coil 42 and the heating surface of the turbine wheel 10 at a predetermined value. Thus, the caulking portion 12a can be heated. The coil arm moving mechanism 117 is shown in FIGS. The coil arm moving mechanism 117 includes a moving mechanism 117a on one end side (attachment pin 119 side of the coil arm 40) shown in FIG. 16, and a moving mechanism on the other end side (arm fixing bolt 121 side of the coil arm 40) shown in FIG. 117b. In the moving mechanism 117a on one end side shown in FIG. 16, an arm fitting 123 is rotatably connected to one end of the coil arm 40 via a mounting pin 119. A guide bracket 125 is fixedly attached to the side surface of the ring 30, and a slide guide 127 (rail) is laid on the guide bracket 125 so as to extend in a direction perpendicular to the surface of the ring 30. The arm fitting 123 is attached to the slide guide 127 so as to be movable along the slide guide 127. An air cylinder 129 is connected between the ring 30 and the arm fitting 123 with a universal joint 130 interposed between the cylinder rod 129a and the arm fitting 123 so as to extend and contract in the extending direction of the slide guide 127. . Therefore, when air is supplied to the air cylinder 129 and the air cylinder 129 is expanded and contracted, one end of the coil arm 40 moves linearly in a direction toward and away from the surface of the ring 30. In the moving mechanism 117 b on the other end side shown in FIG. 17, an arm fitting 131 is fixedly connected to the other end of the coil arm 40 via an arm fixing bolt 121. A guide bracket 133 is fixedly attached to the side surface of the ring 30, and a slide guide 135 (rail) is laid on the guide bracket 133 so as to extend in a direction perpendicular to the surface of the ring 30. The arm fitting 131 is attached to the slide guide 135 so as to be movable along the slide guide 135. An air cylinder 137 is connected between the ring 30 and the arm fitting 131 with a universal joint 138 interposed between the cylinder rod 137a and the arm fitting 131 so as to be extendable and contractable in the extending direction of the slide guide 135. . Therefore, when air is supplied to the air cylinder 137 and the air cylinder 137 is expanded and contracted, the other end of the coil arm 40 moves linearly in a direction approaching and separating from the surface of the ring 30. FIG. 18 shows the arrangement of the arm fitting 131, the guide bracket 133, the slide guide 135, and the air cylinder 137 of the moving mechanism 117b on the other end side. The arm fitting 123, the guide bracket 125, the slide guide 127, and the air cylinder 129 of the moving mechanism 117a (FIG. 16) on the one end side are similarly configured. A constant pressure of air is supplied to the air cylinders 129 and 137 in the shortening direction (retraction direction). As shown in FIG. 15, by arranging the ring 30 at a position close to the surface of the turbine wheel 10 to be heated and supplying air of a constant pressure to the air cylinders 129 and 137 in the shortening direction, the coil arm 40 is The guide roller 98 is urged in the direction toward the surface of the turbine wheel 10 so that the guide roller 98 is always kept in press contact with an unheated position on the heating surface of the turbine wheel 10, and the heating coil 42 and the turbine wheel 10 are heated. The clearance d with the surface is maintained at a predetermined value. In this state, the high frequency current is supplied to the heating coil 42 while rotating the ring 30 at a constant low speed, so that the heating coil 42 keeps the clearance d with the heating surface of the turbine wheel 10 at a predetermined value while the caulking portion 12a. Can be continuously heated. At this time, the guide roller 98 follows the rotation of the ring 30 and rolls on the surface of the turbine wheel 10. The rotation axis of the guide roller 98 is arranged orthogonal to the turbine rotor axis A. When the heating coil 42 is disposed on the opposite side to the coil arm 40 in FIG. 15 and the crimping portion 12a is heated on the surface of the turbine wheel (not shown) facing the surface of the turbine wheel 10 in FIG. A constant pressure of air is supplied to the cylinders 129 and 137 in the extending direction (extrusion direction).

<< Roller frame moving mechanism 139 >>
The roller frame moving mechanism 139 is shown in FIG. The roller frame moving mechanism 139 moves the roller frame 36 along the rail 38 using two chains 141 stretched along the two outer rails 38 a and 38 d. A turnbuckle 145 is connected to both ends of the chain 141 via a connecting plate 143. The hooks of the turnbuckle 145 are hung in holes formed at both ends of the rails 38a and 38d. A shaft (shaft bar) 149 is rotatably attached to and supported by the roller frame 36 via shaft holders 140 and 140. A drive sprocket 147 is fixed to the shaft 151. A handle 151 is attached to the tip of the shaft 149. Further, idler sprockets 146 and 148 are rotatably mounted and supported on the roller frame 36 via shaft holders 142 and 144. The chain 141 is hung on the drive sprocket 147 via idler sprockets 146 and 148. In this state, the turnbuckle 145 is adjusted so that the chain 141 is stretched. Two operators 151 and 151 are manually rotated simultaneously in the same direction as viewed from one handle 151 side by two workers, so that the drive sprockets 147 and 147 are rotated in the same direction. 141 and 141, the roller frame 36 moves along the rail 38. Accordingly, the heating device 11 can be moved in the axial direction of the turbine rotor 1 and moved to the position of the turbine wheel 10 to be heated for positioning.

<Control panel 51>
The control panel 51 in FIG. 4 starts and stops the drive motor 74 of the ring rotation drive mechanism 72, sets the speed and switches the rotation direction, starts and stops power supply to the heating coil 42, and supplies power. Operations such as setting, starting and stopping of air supply to the air cylinders 129 and 137, and switching of the supply direction (extension direction and shortening direction) are performed.

The stress relief processing work of the crimping portion 12a using the heating device 11 having the above configuration can be performed, for example, by the following procedure.
(1) Installation of heating device:
As shown in FIG. 7, the heating device 11 is attached to the turbine rotor 1 that is supported by both ends on the support bases 54, 54 installed on the floor 52 of the temporary storage place in the building such as a nuclear power plant. Install. In addition, the turbine rotor 1 of FIG. 7 shows the example of a low pressure turbine. In the turbine rotor 1, a total of 18 (stages) turbine wheels 10 are formed symmetrically on the shaft portion 2, each having nine (stages), and blades (blades) 14 are mounted on the outer periphery of each turbine wheel 10. . In FIG. 7A, the numbers given above the respective stages are the names (stage numbers) of the respective stages, and are numbers consecutive from the respective stages of the high-pressure turbine. The turbine rotor 1 in the example of FIG. 7 has two stages on the left and right outer sides (16th and 17th stages), and the blade rotor structure of the turbine rotor 1 and the blades 14 is different from the other stages. The stage is not heated by the heating device 11. Therefore, in the heating apparatus 11, the stress relief process of the crimping | crimped part 12a is performed about a total of 28 surfaces of 14 steps | paragraphs of 9th-15th steps on either side, and 2 surfaces of each step | level. Accordingly, the inner diameter of the ring 30 is not limited so long as the coil arm 40 can be moved to a position where the stress relief process on these 28 surfaces can be performed. In this example, the inner diameter of the ring 30 is larger than the outer diameter of the 15th stage turbine blade and the 16th stage turbine. It is set smaller than the outer diameter of the blade. For example, if the outer diameter of the 15th stage turbine blade is about 3.8 meters, the inner diameter of the ring 30 can be set to about 4 meters. At this time, the total width (dimension in the thickness direction) of the ring 30 can be set to about 1.1 meters, for example. Here, it is assumed that the stress relief processing operation is sequentially performed from the fifteenth stage on the right side to the left side to the fifteenth stage on the left side. The heating device 11 is installed as follows. As shown in FIG. 5, four rails 38 are laid on the floor 52 in parallel with the turbine rotor shaft A and two at a symmetrical position with respect to the turbine rotor shaft A as viewed from above. The roller frame 36 is assembled and placed and supported on the rail 38. The ring 30 is assembled and mounted on the four support rollers 34 at the top of the roller frame 36 at a position between the support bases 54 and 54. One end of the coil arm 40 on which the heating unit 43 and the guide roller 98 are mounted is connected to the ring 30 so as to be rotatable by a coil arm mounting pin 119 (FIG. 16). In this state, as shown in FIG. 20, the coil arm 40 is swung outwardly about the coil arm mounting pin 119, and the outer diameter of the turbine rotor 1 passing through the space 31 of the ring 30 (turbine blade outer diameter). Can be retracted to the outside. In a state where the coil arm 40 is retracted to the outside, the roller frame 36 on which the ring 30 is mounted can be moved along the rail 38 in the direction of the turbine rotor axis A without the coil arm 40 interfering with the turbine wheel 10. it can. Therefore, with the coil arm 40 retracted to the outside, the handle 151, 151 (FIG. 19) is operated to move the roller frame 36 along the rail 38, and the position of the turbine wheel 10 where the stress relief processing is performed. Move to. FIG. 5 shows the arrangement of the heating device 11 when performing the first stress removal process (that is, the outer surface of the 15th stage on the right side). When the heating device 11 is moved to the position where the first stress relief process is performed, the other end of the coil arm 40 is connected to the ring 30 via the arm fitting 131 with the arm fixing bolt 121 (FIG. 17). As a result, the heating coil 42 and the high-frequency current transformer 44 are inserted between the blades 14 and 14 of the right-side 15th and 16th stages facing each other. One end of a feeder 46 is connected to the high-frequency current transformer 44. The other end of the feeder 46 is connected to a high frequency inverter 48 and a cooling water circulation unit 50.

(2) Position adjustment:
By operating the handles 151 and 151 (FIG. 19) and finely adjusting the position of the roller frame 36, the heating coil 42 is positioned at a position close to the outer surface of the 15th stage turbine wheel 10. In this state, air at a constant pressure is supplied to the air cylinders 129 and 137 in the shortening direction. As a result, the coil arm 40 is urged toward the outer surface of the 15th stage turbine wheel 10, the guide roller 98 is pressed against the surface, and the clearance d between the heating coil 42 and the surface is a predetermined value. Set to Subsequently, as shown in FIG. 14, the handle 102 of the coil moving mechanism 37 is turned, and the heating coil 42 is moved along the long piece 40a of the coil arm 40 to be positioned at a position facing the caulking portion 12a that performs stress relief processing. To do. Further, the drive motor 74 of the rotation drive mechanism 72 is slightly turned to position the ring 30 at a predetermined start position in the circumferential direction (for example, the position shown in FIG. 1). Now you are ready for the stress relief process.

(3) Start of stress relief processing:
Simultaneously with the start of power supply to the heating coil 42, the drive motor 74 of the ring rotation drive mechanism 72 is activated. As a result, the ring 30 rotates at a constant low speed in the clockwise direction in FIG. 1 (the rotational speed at which a predetermined linear velocity is obtained at the diameter position of the heating portion), and the heating coil 42 is crimped as shown in FIG. Along the circle. At this time, the caulking portion 12a is induction-heated to a sufficient temperature at a position facing the heating coil 42, and is gradually cooled by moving away from the position facing the heating coil 42 after heating. As a result, the caulking portion 12a is continuously subjected to induction heating and slow cooling, and the internal stress is removed. The speed of the drive motor 74 of the ring rotation drive mechanism 72 during heating and the power supplied to the heating coil 42 are set to values that can raise the temperature of the crimping portion 12a to a temperature sufficient to remove the internal stress. For example, when the caulking portion 12a is heated to about 450 degrees Celsius, the caulking portion 12a is slightly deformed by the internal stress, and the internal stress can be removed by annealing to relieve the temperature by slowly cooling to normal temperature. In this case, the linear velocity of the heating portion and the power supplied to the heating coil 42 are set so that the crimping portion 12a is heated to about 450 degrees Celsius. As an example, the linear velocity of the heating part can be set to 30 centimeters / minute, and the output of the heating coil 42 can be set to about 25 kilowatts. The feeder 46 has a sufficient length so that the ring 30 can be rotated 360 degrees.

(4) End of stress relief process:
When the ring 30 is rotated 360 degrees and heating of the entire circumference of the caulking portion 12a is completed, the power supply to the heating coil 42 is stopped, and at the same time, the drive motor 74 is stopped. Next, air is supplied to the air cylinders 129 and 137 in the extending direction to separate the guide roller 98 from the outer surface of the 15th stage turbine wheel 10, and then the drive motor 74 is rotated in the reverse direction so that the ring 30 is returned to the original circumferential direction. Return to the position (position in FIG. 1). If the speed of the drive motor 74 is made variable by an inverter or the like and the drive motor 74 is fast-forwarded during a return operation that does not require heating, the working time can be shortened.

(5) Transfer to the next stress relief processing position and stress relief processing:
When the stress relief process of the crimping portion 12a is finished on the outer surface of the 15th stage turbine wheel 10 as described above, the coil arm 40 is inserted between the 14th stage and the 15th stage and the stress relief process on the two faces facing each other. I do. When the coil arm 40 is moved between the 15th stage and the 16th stage between the 14th stage and the 15th stage, if the ring 30 is moved as it is in the direction of the turbine rotor axis A, the coil arm 40 is moved to the turbine. Interfering with the wheel 10. Therefore, the arm fixing bolt 121 at the other end of the coil arm 40 is removed and the ring rotation driving mechanism 72 is rotated in the reverse direction, so that the ring 30 is slightly rotated counterclockwise from the position shown in FIG. As a result, the coil arm 40 swings around the mounting pin 119 as shown in FIG. 20 and retreats outside the outer diameter of the turbine blade in the space 31 of the ring 30. In this state, the handles 151 and 151 (FIG. 19) are operated to move the roller frame 36 along the rail 38 and move the coil arm 40 between the 14th stage and the 15th stage. When the movement is completed, the coil arm 40 is inserted between the 14th stage and the 15th stage, and the other end of the coil arm 40 is fixed to the ring 30 again by the arm fixing bolt 121. In this state, the stress relief process of the crimping portion 12a is performed on the outer surface of the fourteenth stage in the same procedure as the stress relief process of the crimping portion 12a is performed on the outer surface of the fifteenth stage. When the stress relief processing of the caulking portion 12a is completed on the outer surface of the fourteenth stage, the heating coil 42 is replaced on the left and right sides with respect to the coil arm 40 of FIG. 15 without changing the insertion position of the coil arm 40 (FIG. 13). The heating unit 43 is removed from the slide blocks 107 and 108 together with the coil mounting plate 96, and the direction is reversed and reattached to the slide blocks 107 and 108). The stress removal process of 12a is performed. At this time, air is supplied to the air cylinders 129 and 137 in the extending direction so that the guide roller 98 is pressed and brought into contact with the inner surface of the fifteenth stage turbine wheel 10, so that the heating coil 42 and the inner surface of the turbine wheel 10 are brought into contact with each other. The stress removal processing is performed while maintaining the clearance d at a predetermined value.

(6) Repeat:
Thereafter, similarly, the roller frame 36 is sequentially moved along the rail 38 in the left direction in FIG. 7A, and stress-relieving processing is performed for each two facing surfaces at each position. At a position where the ring 30 interferes with the left sixteenth stage, the coil arm 40 is replaced with the guide brackets 125 and 133 (FIG. 6) of the left ring 30-2 of the ring 30 to perform stress relief processing.

(7) Operation after the end of the stress relief process for all stages:
When the stress relief processing of the caulking portion 12a is completed from the 15th stage on the right side to the 15th stage on the left side, the ring 30 is disassembled, the roller frame 36 is removed, the rail 38 is removed, and the entire heating apparatus 11 is replaced with another turbine. It can convey to the storage position of a rotor, and can perform the stress relief process similarly about the turbine rotor. Since the turbine rotor 1 that has finished the stress relief processing of the caulking portion 12a can slide the blade 14 (FIG. 2) in the circumferential direction, the stop key 22 (FIG. 2) is pulled out, the stop blade 14 ′ is pulled out, and each blade 14 can be slid and pulled out from the notch 20 in which the stop blade 14 ′ was disposed.

According to the heating device 11 having the above configuration, the following effects can be obtained.
(A) Since the caulking portion 12a of the turbine wheel 10 is heated by the heating coil 42 and further gradually cooled to remove the internal stress of the caulking portion 12a to facilitate the release of the caulking state, the caulking described in Patent Document 1 Compared to the technique of cutting the part to release the caulking state, a strong reaction force due to cutting does not occur. Therefore, it is not necessary to make the structure of the ring 30 and the roller frame 36 strong enough to withstand the cutting reaction force, the rigidity of the ring 30 is sufficient to support its own weight, and the output of the drive motor 74 is relatively small. This is a simple configuration.
(B) A heating method using a gas burner is also conceivable as a heating means for removing stress, but there are many cases where a strong limit is imposed on the use of fire such as gas especially in a nuclear power plant building. It is not preferable from the viewpoint of work safety and prevention of disasters such as fire, which requires many man-hours such as the need for curing to prevent sparks from being scattered and the need to strictly manage high-pressure combustible gas. On the other hand, the heating device 11 does not use fire for heating but uses electricity. In addition, the heating range is very limited, so there is almost no need for fire prevention measures, and man-hours for management and actual work are greatly reduced.
(C) By providing a mechanism for swinging the coil arm 40 to the outside of the ring 30, it is not necessary to remove the coil arm 40 or the heating coil 42 every time the next stage is shifted, and the work efficiency is greatly improved. I can expect.
(D) Since the ring 30, the roller frame 36, the rail 38, etc. can be respectively divided, they are excellent in portability and installation, and can be removed as soon as the heating operation is completed. The space required for storage can also be reduced.

  In the above-described embodiment, the ring 30 is continuously rotated. However, the crimping portion 12a can be heated while being intermittently rotated by a predetermined minute angle. In the above embodiment, when the caulking portion 12a is heated, the rotation of the turbine rotor 1 is stopped and the heating coil 42 is rotated. Instead, the rotation of the heating coil 42 is stopped, The turbine rotor 1 can also be rotated. In the above embodiment, the case where the internal stress is removed by applying the present invention to the caulking portion of the tangential entry type wing implant portion structure has been described. However, the present invention is not limited to this, and other than the tangential entry type. It can also be applied to remove internal stress in the caulking portion of the implanted portion structure.

  DESCRIPTION OF SYMBOLS 1 ... Turbine rotor, 10 ... Turbine wheel, 11 ... Heating device, 12a ... Caulking part, 14 ... Blade | wing, 30 ... Ring, 36 ... Roller frame (roller support frame), 38 ... Rail, 40 ... Coil arm (coil mounting member) , Arm-shaped coil mounting member), 42 ... heating coil, 44 ... high frequency current transformer (power supply device), 48 ... high frequency inverter (power supply device), 52 ... floor (foundation), 72 ... ring rotation drive mechanism, 98 ... Guide roller, 117 ... Coil arm moving mechanism (coil mounting member moving mechanism), d ... Clearance between side surface of turbine wheel and heating coil, A ... Shaft of turbine rotor

Claims (11)

A plurality of blades are fitted and arranged along the outer peripheral edge of the turbine wheel, and the side of the turbine wheel is caulked from the outside along the circumferential direction at the fitting position to form a crimped portion. For a turbine rotor having a structure with a strong joint, an apparatus for heating the caulking part,
A roller support frame supported by a foundation;
A plurality of support rollers supported rotatably on the roller support frame in a direction around the axis;
A ring mounted and supported on the plurality of support rollers so as to be rotatable in a direction around the axis;
A ring rotation drive mechanism for rotating the ring in the direction around the axis;
A heating coil mounted on the ring;
A power supply device for supplying a high-frequency current to the heating coil,
The ring is arranged coaxially to a turbine rotor supported on the foundation;
The caulking part heating device, wherein the heating coil is disposed facing the caulking part and induction-heats the caulking part at the facing position.   The caulking section heating device according to claim 1, wherein the roller support base is supported by the rail so as to be movable along a rail supported by the foundation in parallel with an axis of the turbine rotor.   The crimping part heating apparatus according to claim 1 or 2, wherein the heating coil is mounted on the ring so as to be movable in a radial direction of the turbine rotor. The heating coil is mounted on the ring via a coil mounting member;
The coil mounting member is mounted with a guide roller in addition to the heating coil,
The guide roller is moved between the coil mounting member and the ring in a direction in which the coil mounting member is moved toward and away from the surface to which the side surface of the turbine wheel belongs with respect to the ring. A coil mounting member moving mechanism that contacts the side surface is arranged,
The guide roller rotates following the rotation of the ring in a state of being in contact with the side surface of the turbine wheel by the coil mounting member moving mechanism,
The caulking according to any one of claims 1 to 3, wherein a clearance between the side surface of the turbine wheel and the heating coil is maintained at a predetermined value by contact between the guide roller and the side surface of the turbine wheel. Part heating device. The heating coil is mounted on the ring via an arm-shaped coil mounting member,
One end of the arm-shaped coil mounting member is rotatably connected to the ring,
The caulking section heating device according to any one of claims 1 to 4, wherein the arm-shaped coil mounting member swings about the one end and is connected to the ring so as to be retractable to the outside of the ring.   The caulking part heating device according to any one of claims 1 to 5, wherein the ring is configured to be reassembled by being divided at a plurality of locations in a circumferential direction.   7. The driving mechanism according to claim 1, wherein the driving mechanism transmits a driving force to the ring via at least one of the plurality of support rollers to rotationally drive the ring in an axial direction. The caulking part heating apparatus as described in. Using the heating device according to any one of claims 1 to 7,
The heating coil is disposed so as to face the caulking portion on the side surface of the turbine wheel,
While the high-frequency current is supplied from the power supply device to the heating coil, the ring rotation driving mechanism is driven to rotate the ring in the direction around the axis of the turbine rotor, and the caulking portion is positioned at a position where the heating coil faces. A method of removing the internal stress of the caulking portion by sequentially cooling the position of the caulking portion and gradually cooling the caulking portion moving away from the position facing the heating coil after the heating. A plurality of blades are fitted and arranged along the outer peripheral edge of the turbine wheel, and the side of the turbine wheel is caulked from the outside along the circumferential direction at the fitting position to form a crimped portion. For a turbine rotor having a structure with a strong joint, a method of removing internal stress of the caulking portion,
A heating coil is arranged facing the crimped portion on the side surface of the turbine wheel,
The heating coil is relatively rotated in the direction around the axis of the turbine rotor, and the position of the caulking portion that the heating coil faces is sequentially moved, while supplying a high-frequency current to the heating coil and the position at which the heating coil is facing. Inductive heating of the caulking part,
A method of removing internal stress of the caulking portion by gradually cooling the caulking portion that is away from the facing position with the heating coil after the heating. The relative rotation of the heating coil in the direction around the axis of the turbine rotor is
The method according to claim 9, wherein the rotation is performed by stopping rotation of the turbine rotor around the axis and rotating the heating coil around the axis. The relative rotation of the heating coil in the direction around the axis of the turbine rotor is
The method according to claim 9, wherein the rotation is performed by stopping the rotation of the heating coil about the axis and rotating the turbine rotor about the axis.

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