JP2014109242A - Clearance measurement system and clearance measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clearance measurement system capable of measuring an initial clearance between a tip of a moving blade and an inner wall surface of a casing during a turning operation, and a clearance measurement method.SOLUTION: A moving blade 15 brought into point contact with a sphere 35 displaces the sphere 35 and a contactor 33b. A displacement gage 33 detects each of amounts of displacement of the sphere 35 and the contactor 33b by each moving blade 15 brought into point contact with the sphere 35. An operation part computes an initial clearance between a tip of each moving blade 15 and an inner wall surface of a casing by subtracting displacement, corresponding to each moving blade 15, from the length of a known extension part.

Description

  The present invention relates to a clearance measuring system and a clearance measuring method for measuring a clearance between a tip of a rotating body such as a moving blade of a turbine and an inner wall surface of a casing surrounding the rotating body before the operation of the turbine.

  In a general turbine (for example, a gas turbine), a rotor, which is a rotating shaft, is rotatably supported by a casing, a moving blade is installed on the outer periphery of the rotor, and a stationary blade is installed on the inner wall of the casing. A plurality of the moving blades and the stationary blades are alternately arranged in a working fluid (for example, combustion gas) passage. In the process in which the working fluid flows through the steam passage in which the moving blades and the stationary blades are disposed, the moving blades and the rotor to which the moving blades are attached are rotationally driven.

  In such a turbine, the clearance between the tip of a rotor blade that is a rotating body and the inner wall surface of a casing that surrounds the rotor blade greatly affects the performance of the turbine. That is, if this clearance is large, the performance of the turbine is degraded due to leakage of the working fluid from the clearance. Therefore, when the turbine is operating, it is important to measure whether this clearance is within appropriate tolerances.

  As an apparatus for measuring the clearance in such a turbine, for example, Patent Document 1 discloses a clearance in which a probe is inserted into an opening of a casing during the high-speed rotation of a rotor and electromagnetic energy is radiated from the tip of the probe. A detection method is described. This detection method is a non-contact detection method for detecting clearance by radiating electromagnetic energy from the tip of the probe and detecting the electromagnetic energy reflected by the tip of the rotating moving blade by the probe.

  Further, although the clearance in the turbine is not directly detected, for example, in Patent Document 2, a measurement rod is inserted into the opening of the casing during high-speed rotation of the rotor, and a moving blade is inserted at the tip of the measurement rod. A touch sensor for detecting whether or not the tip is in contact is described. When the tip of the measuring rod detects contact with the tip of the moving blade, the touch sensor moves the measuring rod in the pulling direction by a predetermined amount from the opening of the casing by the pinion. When it is detected that the tip of the moving blade is close to the inner wall side of the casing until the limit value allowed as the clearance is reached, the operation of the turbine is stopped.

JP 2010-106836 A JP 2001-50737 A

  In particular, in a gas turbine, after the normal operation in which the rotor blades and the rotor rotate at high speed by combustion gas is stopped, the air having a relatively high temperature moves upward and the air having a relatively low temperature moves downward. . As a result, the upper casing is thermally expanded by the heat of the upper air, and the entire casing is deformed so as to be warped. Thus, when deformation occurs in the entire casing, the next time the turbine is operated, the tip of the moving blade may come into contact with the inner wall surface of the casing. Therefore, normally, when the normal operation is stopped due to the high-speed rotation of the turbine, an operation called a turning operation is performed. In the turning operation, the rotor is rotated at a low speed (for example, 5 [rpm] or less) by an electric motor, and the air in the turbine is circulated to uniformly cool the turbine.

  However, even if the turbine is cooled by turning operation, the clearance between the tip of the moving blade and the inner wall surface of the casing is within an allowable tolerance that does not hinder the operation of the turbine at the next turbine operation. You cannot judge unless you actually measure it. Therefore, for example, before operating the turbine, it is necessary to perform a turning operation and measure the clearances for all the moving blades. Hereinafter, the clearance between the tip of the moving blade and the inner wall surface of the casing during the turning operation by low-speed rotation before the turbine is rotated at high speed is referred to as “initial clearance”. In the non-contact type clearance detection method described in Patent Document 1, there is a possibility that the influence of the heat effect correction circuit or the like becomes noise, and accurate initial clearance cannot be measured in a low-speed rotation range. Even when a capacitance type sensor and an eddy current type sensor are used as a non-contact type clearance detection device, there is a possibility that the same problem as described above may be caused.

  Further, the touch sensor described in Patent Document 2 merely detects whether or not the tip of the moving blade is in contact with the tip of the measurement rod by the measurement rod inserted into the opening of the casing. The clearance itself cannot be measured.

  An object of the present invention is to provide a clearance measuring system and a clearance measuring method capable of measuring an initial clearance between a tip of a moving blade and an inner wall surface of a casing during a turning operation.

  A clearance measurement system according to the present invention for solving the above-described problems includes a tip of a moving blade fixed in parallel with the outer circumference of a rotor rotatably supported in a turbine along the circumferential direction. A clearance measurement system for measuring a clearance with an inner wall surface of a casing of the turbine, wherein the casing has a cylindrical shape, a main body disposed in the casing, and a detection side portion of the main body from the detection side portion. The rod has a rod extending in the axial direction, a displacement meter having a contact attached to the tip of the rod, and has a cylindrical shape. The axial center line of the rod intersects the center on the end surface on the detection side. A circular support hole is formed, and a spherical body to be brought into contact with the moving blade is supported by the support hole, and is connected to the support connected to the housing and the displacement meter so as to be able to communicate with the moving blade by the working fluid. And the rotor A calculation unit that measures an initial clearance that is a clearance during a turning operation that rotates the rotor at a lower speed than a normal operation that rotates, and the detection side portion of the contact makes point contact with the sphere, and the sphere Has a protrusion that is partially protruded from the support hole on the end surface on the detection side of the support, and the casing and the support are arranged from the outer wall surface of the casing to the moving blade. When installed in a measurement opening formed penetrating up to the formed working fluid passage, the entire amount of the sphere is inserted into the working fluid passage, and the displacement meter is operated in the turning operation. Sometimes, the tip of the moving blade makes point contact with the protruding portion of the sphere, and the sphere is pushed toward the contact to detect the displacement of the contact. Received from displacement meter Based on the serial displacement, it is characterized in that determining said initial clearance corresponding to the moving blade. Among these, the said calculating part is based on the length from the said inner wall surface in the state in which the said housing | casing and the said support body are installed in the said measurement opening part to the top part on the detection side of the said spherical body, and the said displacement. The initial clearance may be calculated.

  Since the present invention employs a contact method in which a sphere is brought into point contact with a moving blade and the displacement of the sphere is measured, it is possible to suppress the influence of noise generated during low-speed rotation operation such as turning operation. This makes it possible to measure the initial clearance more accurately than the non-contact measurement method that is susceptible to exposure. Moreover, since the part which contacts a moving blade is made into the spherical body, durability with respect to a contact with a moving blade can also be improved.

  In the clearance measurement system according to the present invention, it is preferable that the contactor has a detection-side end surface that is a plane perpendicular to the axial direction of the rod, and the plane makes point contact with the sphere.

  In the present invention, even when a force including a frictional force due to point contact is received from a moving blade, the end surface on the detection side of the contact always makes point contact with the top of the communication side of the sphere. Accordingly, in the displacement meter, since the displacement in the axial direction of the spherical rod and the displacement in the axial direction of the contact are the same, accurate initial clearance can be measured.

  Further, in the clearance measurement system according to the present invention, the support has a hole diameter adjusting mechanism installed on the inner surface side of the end surface where the support hole is formed, and the hole diameter adjusting mechanism has a ring shape. Presenting and having an adjustment hole formed in the center that allows adjustment of the hole diameter, supporting the sphere in a state in contact with the peripheral edge of the adjustment hole, and adjusting the diameter of the adjustment hole, It is preferable to adjust the allowance of the sphere.

  In the present invention, in the case where contact between the tip of all the moving blades and the sphere is not detected in a certain measurement opening, the adjustment hole can be expanded to adjust the size of the sphere. , Contact with the sphere can be detected for all moving blades.

  In the clearance measurement system according to the present invention, the casing has a cylindrical shape, and a detection side portion of the outer surface has a stepped portion formed with a reduced diameter, and the stepped portion has a screw on the inner surface. A step fitting portion formed by cutting, the support having a cylindrical shape having an outer diameter smaller than the inner diameter of the housing, supporting the displacement meter therein, and having a predetermined outer surface By having a support fitting part formed by cutting a screw in a range, the support fitting part and the step fitting part are connected to the case by fitting and rotating. It is preferable that the housing can move in the axial direction of the housing.

  In the present invention, when the contact between the tip of all the moving blades and the sphere is not detected in a certain measurement opening, the top on the detection side of the sphere can be brought close to the tip of the moving blade. The contact with the sphere can be detected.

  Further, the clearance measurement system according to the present invention has a cylindrical shape, and includes a measurement device support fitting portion formed by being threaded on the inner surface, and an insertion hole opened on the end surface on the detection side. An apparatus support body, the support body having a fitting portion formed by threading an outer surface and a stepped portion having a diameter reduced from a detection side end of the fitting portion of the outer surface. The measuring device support can be provided with a circular ring-shaped shim that contacts the inner surface of the end surface on the detection side, and the step portion of the support is inserted into the insertion hole, and the measuring device support When the fitting portion and the fitting portion are fitted together, it is possible to connect to the support body, and when the shim is installed and connected to the support body, an end surface opposite to the detection side of the shim is When contacting the support and connecting to the support without installing the shim, When the inner surface of the end surface is in contact with the support, and the housing and the support are inserted and installed in the measurement opening, the end surface on the detection side is the working fluid passage in the measurement opening. It is preferable to contact the flange formed on the side.

  In the present invention, the length from the inner wall surface to the top on the detection side of the sphere can be adjusted by adjusting the thickness of the shim installed on the measuring device support or removing the shim itself. Therefore, if contact between the tip of all blades and a sphere is not detected in a certain measurement opening, the length can be adjusted, so that contact with the sphere is detected for all blades. Can do.

  Further, the clearance measuring method according to the present invention includes a tip of a moving blade fixed in parallel with the outer periphery of a rotor rotatably supported in the turbine along the circumferential direction, and a casing of the turbine. A clearance measuring method for measuring a clearance with an inner wall surface, the step of starting a turning operation for rotating the rotor at a lower speed than a normal operation in which the rotor rotates by receiving the pressure of the fluid, A displacement having a cylindrical housing, a main body arranged in the housing, a rod extending from the detection side portion of the main body in the axial direction of the housing, and a contact attached to the tip of the rod A cylindrical support hole is formed on the detection side end surface, and a circular support hole intersecting the center of the rod is formed at the center, and a spherical body to be brought into contact with the moving blade is supported by the support hole. A clearance measuring device including a support coupled to the housing is inserted into a measurement opening formed through the outer wall surface of the casing to a working fluid passage in which a moving blade is disposed. And the step of making contact with the detection side portion of the contactor, and the moving blade on the spherical body having a protrusion protruding partly from the support hole of the end surface on the detection side of the support Detecting the displacement of the contact caused by the point contact of the tip of the ball and the spherical body being pushed toward the contact, and the initial clearance being the turning operation based on the displacement of the contact And a measuring step for measuring the clearance.

  Since the present invention employs a contact method in which a sphere is brought into point contact with a moving blade and the displacement of the sphere is measured, it is possible to suppress the influence of noise generated during low-speed rotation operation such as turning operation. This makes it possible to measure the initial clearance more accurately than the non-contact measurement method that is susceptible to exposure. Moreover, since the part which contacts a moving blade is made into the spherical body, durability with respect to a contact with a moving blade can also be improved.

  In the clearance measurement method according to the present invention, in the step of detecting the displacement, the displacement of the contact is detected for all the moving blades corresponding to the measurement opening into which the clearance measurement device is inserted. If not, it is preferable to have a step of preparing the ance of the sphere.

  In the present invention, in the case where contact between the tip of all the moving blades and the sphere is not detected in a certain measurement opening, the adjustment hole can be expanded to adjust the size of the sphere. , Contact with the sphere can be detected for all moving blades.

  In the clearance measurement method according to the present invention, in the step of detecting the displacement, the displacement of the contact is detected for all the moving blades corresponding to the measurement opening into which the clearance measurement device is inserted. If not, it is preferable to have a step of moving the support to the detection side with respect to the casing supported by the measurement opening.

  In the present invention, when the contact between the tip of all the moving blades and the sphere is not detected in a certain measurement opening, the top on the detection side of the sphere can be brought close to the tip of the moving blade. The contact with the sphere can be detected.

  In the clearance measurement method according to the present invention, in the step of inserting the clearance measurement device into the measurement opening and installing the clearance measurement device, the clearance measurement device has a cylindrical shape, and a circular ring-shaped shim is applied to the inner surface side of the end surface on the detection side. The end face on the detection side of the measuring device support connected to the detection side of the support, with the end face opposite to the detection side of the shim in contact with the support, In the step of contacting the flange formed on the working fluid passage side in the measurement opening and detecting the displacement, all the movements corresponding to the measurement openings into which the clearance measurement device is inserted are provided. For the blade, when the displacement of the contact cannot be detected, the clearance measurement device is extracted from the measurement opening, and the shim installed on the measurement device support is removed, or A step of installing a shim that is thinner than the shim, connecting the measurement device support to the support again, and inserting the clearance measurement device into the measurement opening; Yes.

  In the present invention, the length from the inner wall surface to the top on the detection side of the sphere can be adjusted by adjusting the thickness of the shim installed on the measuring device support or removing the shim itself. Therefore, if contact between the tip of all blades and a sphere is not detected in a certain measurement opening, the length can be adjusted, so that contact with the sphere is detected for all blades. Can do.

  The present invention can provide a clearance measuring system and a clearance measuring method capable of measuring an initial clearance between a tip of a moving blade and an inner wall surface of a casing during a turning operation.

FIG. 1 is a schematic configuration diagram of a gas turbine in which an initial clearance device according to Embodiment 1 is installed. FIG. 2-1 is an overall external view of the initial clearance measuring device. FIG. 2-2 is a cross-sectional view of the tip portion of the initial clearance measuring device. FIG. 2C is a diagram illustrating a state in which the sphere of the initial clearance measuring device is in contact with the tip of the moving blade during the turning operation. FIG. 3 is a diagram illustrating a state in which the initial clearance measuring device according to the first embodiment is installed in the casing of the gas turbine. FIG. 4 is a diagram illustrating the displacement amount of each rotor blade measured by the displacement meter of the first embodiment. FIG. 5-1 shows that the inner diameter of the second step portion of the sphere support is larger than the diameter of the sphere in the structure of the detection side portion of the initial clearance measuring device, and the inner surface of the second step portion from the outer surface of the sphere. It is a figure which shows the structure which has a gap | interval. FIG. 5B is a diagram illustrating a measurement error that occurs when the sphere of the initial clearance measurement device contacts the tip of the moving blade. FIG. 6A is a diagram illustrating a configuration of a contact of the initial clearance measuring device according to the second embodiment. FIG. 6B is a diagram illustrating a state in which the sphere of the initial clearance measuring device is in contact with the tip of the moving blade. FIG. 7-1 is a diagram illustrating adjustment of a sphere protrusion by the hole diameter adjusting mechanism of the third embodiment. FIG. 7-2 is a diagram illustrating a state in which the allowance of the sphere is adjusted to the maximum by the hole adjusting mechanism of the third embodiment. FIG. 8-1 is a diagram illustrating an example of the structure of the hole diameter adjusting mechanism of the third embodiment. 8-2 is a figure which shows the blade | wing body of the hole diameter adjustment mechanism of Embodiment 3. FIG. FIG. 8-3 is a diagram illustrating a hole diameter adjusting ring of the hole diameter adjusting mechanism according to the third embodiment. FIG. 8-4 is a diagram illustrating a state in which the diameter of the sphere support adjustment hole of the hole diameter adjustment mechanism of the third embodiment is adjusted. FIG. 9 is a flowchart illustrating an initial clearance measuring method according to the third embodiment. FIG. 10 is a cross-sectional view of a main part of the initial clearance measuring device according to the fourth embodiment. FIG. 11A is a cross-sectional view of a main part in a state where a shim is installed in the initial clearance measuring device according to the fifth embodiment. FIG. 11B is a cross-sectional view of the main part in a state where the shim is removed in the initial clearance measuring apparatus according to the fifth embodiment. FIG. 12 is a cross-sectional view of a main part of the initial clearance measuring device according to the sixth embodiment. FIG. 13A is a cross-sectional view of the main part of the initial clearance measuring device according to the seventh embodiment. FIG. 13-2 is an operation explanatory diagram of the initial clearance measuring device according to the seventh embodiment. FIG. 14 is a cross-sectional view of a main part of the initial clearance measuring device according to the eighth embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings.

[Embodiment 1]
(Schematic configuration of the gas turbine 1)
FIG. 1 is a schematic configuration diagram of a gas turbine in which an initial clearance device according to Embodiment 1 is installed. Hereinafter, the outline of the structure of the gas turbine 1 according to the first embodiment will be described with reference to FIG.

  As shown in FIG. 1, in the gas turbine 1 according to the first embodiment, the casing 11 has a hollow shape, and a rotor 12 as a rotating shaft is rotatably supported by a plurality of bearings 13. A moving blade 15 and a stationary blade 16 are disposed in the casing 11. A plurality of moving blades 15 are juxtaposed and fixed to the outer periphery of a disk-shaped rotor disk 14 formed on the rotor 12 along the circumferential direction. A plurality of stationary blades 16 are arranged and fixed to the inner wall of the casing 11 along the circumferential direction. These moving blades 15 and stationary blades 16 are alternately arranged along the axial direction of the rotor 12.

  In the casing 11, the moving blade 15 and the stationary blade 16 are disposed, and a gas passage 17 through which steam flows is formed. A combustor 18 is formed in the gas passage 17 as an inlet to which steam is supplied, and an outlet 19 is formed as an outlet from which the steam is discharged to the outside.

  Further, the casing 11 is formed with a measurement opening 21 formed so as to penetrate from the outer wall surface to the inner wall surface (casing inner wall surface 23) in a circular shape. A plurality of measurement openings 21 are formed along the circumferential direction on the wall surface of the casing 11 facing the extending direction of the moving blade 15 in each stage in the axial direction of the rotor 12. FIG. 1 shows a state where the initial clearance measuring device 31 is inserted and installed in one of the plurality of measurement openings 21. The initial clearance measuring device 31 measures the clearance (initial clearance) between the tip of the moving blade 15 and the casing inner wall surface 23 of the casing 11 during the turning operation, and is connected to the calculation unit 51 via the communication line 52. Has been. The computing unit 51 obtains the initial clearance by computing the initial clearance based on the measurement information transmitted from the initial clearance measuring device 31.

  Note that a plurality of measurement openings 21 are formed along the circumferential direction on the wall surface of the casing 11 facing the extending direction of the moving blade 15 in each stage of the rotor 12 in the axial direction. There is no need to form. In addition, the measurement opening 21 is formed in a portion corresponding to each stage of the rotor blade 15 in the axial direction of the rotor 12, but it is not always necessary to form the measurement opening 21 in a part corresponding to each stage. It is good also as what forms only in the part corresponding to the specific step of the casing 11 in which elongation is especially worried.

(Schematic operation of the gas turbine 1)
Next, an outline of the operation of the gas turbine 1 will be described with reference to FIG.

  The combustion gas injected from the combustor 18 of the gas turbine 1 passes through the first stage stationary blade 16 and is blown to the first stage blade 15 to rotate the plurality of blades 15 and the rotor 12 to which these are attached. . The combustion gas flows from the first stage blade 15 to the last stage blade 15 and is discharged to the outside through the discharge port 19.

(Structure of initial clearance measuring device 31)
FIG. 2-1 is an overall external view of the initial clearance measuring device, FIG. 2-2 is a cross-sectional view of the tip portion of the initial clearance measuring device, and FIG. 2-3 is a sphere of the initial clearance measuring device. FIG. 3 is a diagram showing a state in which is in contact with the tip of a moving blade during a turning operation. The structure of the initial clearance measuring device 31 according to the first embodiment will be described with reference to FIGS.

  The initial clearance measurement device 31 according to the first embodiment includes a measurement device housing 32, a displacement meter 33, a displacement meter support 34, a sphere 35, a sphere support 36, and a measurement device support 37. As described above, the initial clearance measuring device 31 is inserted into the measurement opening 21 formed in the casing 11. Hereinafter, in the initial clearance measuring device 31, the side inserted into the measurement opening 21. Is denoted as “detection side”, and the side on which the communication line 52 extends is denoted as “communication side”.

  The measuring device casing 32 constitutes the outer shape of the cylindrical initial clearance measuring device 31.

  The displacement meter support 34 is a cylindrical member that supports the main body of the displacement meter 33. The communication side portion of the outer surface has a threaded fitting portion 34a, and the detection side portion. Similarly, a fitting part 34b in which a screw is cut is formed. In addition, a fitting portion 32a that is threaded is formed on the inner side of the measuring device casing 32 on the detection side in the longitudinal direction, and the fitting portion 32a and the fitting portion 34a are formed. And the measuring device housing 32 and the displacement meter support 34 are connected to each other. A part of the displacement meter 33 is accommodated in the cylinder of the measurement device housing 32 by the connection between the measurement device housing 32 and the displacement meter support 34. As illustrated in FIG. 2B, a communication line 52 extends from a communication side portion of the displacement meter 33, and the communication line 52 passes through the inside of the measurement device housing 32 to communicate with the communication device of the measurement device housing 32. It extends to the outside from the opening and is connected to the calculation unit 51. In addition, an opening is formed in the end surface on the detection side of the displacement meter support 34, and the contact rod 33a faces the detection side from the detection side portion of the displacement meter 33 supported by the displacement meter support 34. And extends through the opening. The axial center line of the contact rod 33 a substantially coincides with the axial center line of the measuring device housing 32. A contact 33b having a convex shape toward the detection side is attached to the detection-side tip of the contact rod 33a. Further, a spring is built in the displacement meter 33, and when the tip of the contactor 33b is pushed to the communication side, the contactor rod 33a moves to the inside of the displacement meter 33 (communication side direction). Receive a biasing force.

  The spherical body support 36 is a cylindrical object formed with a plurality of stepped portions that support the spherical body 35 that is in point contact with the tip of the moving blade 15 at the time of initial clearance measurement. A threaded fitting portion 36a is formed on the communication side. By fitting the fitting portion 34b of the displacement meter support 34 and the fitting portion 36a, the displacement meter support 34 and the sphere support 36 are connected. Further, on the outer surface of the cylindrical spherical support 36, the first step portion 36d having a reduced diameter and the first step portion 36d having a reduced diameter are provided in the direction from the communication side to the detection side. Two step portions 36e are formed. A circular sphere support hole 36c where the axial center line of the contact rod 33a intersects with the center is opened at the detection side end face of the second step portion 36e. The sphere 35 is supported inside the sphere support 36 while being in contact with the peripheral edge of the sphere support hole 36c. As a result, the sphere 35 has an allowance in which a portion of the second stepped portion 36e is exposed in a convex shape from the end surface on the detection side. Further, the top of the sphere 35 on the communication side is in point contact with the tip of the contact 33 b of the displacement meter 33. In addition, a threaded fitting portion 36b is formed on the outer surface of the first step portion 36d.

  The measurement device support 37 is fitted to the sphere support 36 and, when the initial clearance measurement device 31 is inserted into the measurement opening 21 of the casing 11, comes into contact with the flange portion 22 to be described later and the initial clearance. It is a cylindrical object that supports the entire measuring device 31. On the inner surface of the measuring device support 37, a fitting portion 37a in which a screw is cut is formed. The detection side of the measuring device support 37 is formed with a support surface 37c that comes into contact with the flange portion 22 described later, and the second step portion 36e of the sphere support 36 is inserted into the measuring device support 37. The insertion hole 37b to be opened is opened. In addition, the measuring device support 37 is connected to the sphere support 36 by inserting the second step portion 36e through the insertion hole 37b and fitting the fitting portion 36b and the fitting portion 37a as described above. Is done.

  As described above, the initial clearance measurement device 31, the calculation unit 51, and the communication line 52 constitute a clearance measurement system.

  The calculation unit 51 is arranged outside the measurement device housing 32 and connected to the displacement meter 33 in the measurement device housing 32 via the communication line 52, but is not limited thereto. Instead, the structure may be built in the measurement device housing 32.

  The displacement meter support 34 and the sphere support 36 correspond to a support, the fitting portion 37a corresponds to a measuring device support fitting portion, and the second step 36e is a step of the support. It corresponds to.

(Initial clearance measurement method using the initial clearance measuring device 31)
FIG. 3 is a diagram illustrating a state in which the initial clearance measuring device according to the first embodiment is installed in the casing of the gas turbine, and FIG. 4 illustrates the displacement amount of each moving blade measured by the displacement meter according to the first embodiment. FIG. A method for measuring the initial clearance will be described with reference to FIGS. 3 and 4.

  First, an operator who wants to measure the initial clearance starts the turning operation for the gas turbine 1.

  Next, the operator inserts the initial clearance measuring device 31 into the measurement opening 21 of the casing 11 from the longitudinal detection side. At this time, the initial clearance measuring device 31 slides the moving blade 15 in the measuring opening 21 while the outer surface of the measuring device housing 32 and the inner wall surface 21 a of the opening that is the inner surface of the measuring opening 21 are in sliding contact. It moves toward the gas passage 17 in which is disposed.

  As shown in FIG. 3, a ring-shaped flange portion 22 is fixed to the inner surface of the gas passage 17 side portion of the measurement opening 21. The end surface of the flange portion 22 on the gas passage 17 side and the casing inner wall surface 23 of the casing 11 exist on substantially the same plane. When the initial clearance measuring device 31 further moves in the measurement opening 21, the second step portion 36 e of the sphere support 36 is inserted into the hole of the ring-shaped flange portion 22 and is in sliding contact with the flange portion inner wall surface 22 a. The support surface 37 c of the measurement device support 37 abuts on the measurement device support surface 22 b of the flange portion 22. At this time, at least a part of the second step portion 36 e protrudes into the gas passage 17, or all of the protruding portion from the detection side end face of the second step portion 36 e of the sphere 35 is the gas passage 17. Make sure that it is inside. As described above, a portion of the second step portion 36 e and the sphere 35 that protrudes from the measurement opening 21 into the gas passage 17 is referred to as an “extension portion” of the initial clearance measuring device 31. In this way, the initial clearance measuring device 31 is installed in the measurement opening 21. At this time, the length from the casing inner wall surface 23 (the end surface of the flange portion 22 on the gas passage 17 side) to the top of the spherical body 35 on the detection side is referred to as “length of the extended portion”. The length of the extended portion of the initial clearance measuring device 31 is measured in advance and is known in advance.

  Thus, when the initial clearance measuring device 31 is installed in the measurement opening 21 during the turning operation, as shown in FIG. 2-3, a plurality of moving blades 15 arranged in parallel with the specific rotor disk 14 are arranged. The tips are in point contact with the sphere 35 one after another. The moving blade 15 that is in point contact with the sphere 35 displaces the sphere 35 in the communication side, that is, in the direction of the arrow shown in FIG. 2-3, and accordingly, the contact 33b is also displaced. As shown in FIG. 4, the displacement meter 33 detects the amount of displacement of the spherical body 35 and the contact 33 b by each moving blade 15 that makes point contact with the spherical body 35. The displacement meter 33 that has detected the displacement of the sphere 35 and the contact 33 b by each moving blade 15 transmits displacement information to the computing unit 51 via the communication line 52. The calculation unit 51 that has received the displacement information subtracts the displacement corresponding to each moving blade 15 from the length of the known extended portion, thereby initial clearance between the tip of each moving blade 15 and the casing inner wall surface 23. Is calculated, and the calculated initial clearance is stored.

  The operator continues the turning operation of the gas turbine 1, inserts the initial clearance measuring device 31 into each of the plurality of measurement openings 21 formed in the casing 11, and similarly measures the initial clearance. To do. Then, when all the measured initial clearances are within a predetermined tolerance, the operator determines that normal operation by high-speed rotation of the gas turbine 1 is possible, and starts normal operation.

  The calculation unit 51 may be provided with a predetermined display, and on this display, a graph of the displacement of the sphere 35 and the contact 33b corresponding to each rotor blade 15 shown in FIG. 4 may be displayed. It is good also as what displays the value of the initial clearance in each measurement opening 21 memorized and memorized. Thus, the operator can visually confirm the initial clearance in each measurement opening 21.

  The configuration and measuring method of the initial clearance measuring device 31 as described above employs a contact method in which the sphere 35 is brought into point contact with the moving blade 15 and the displacement of the sphere 35 is measured. Therefore, a low-speed rotation operation such as a turning operation is performed. It is possible to suppress the influence received from noise generated at times. This makes it possible to measure the initial clearance more accurately than the non-contact measurement method that is susceptible to noise.

  In addition, since the initial clearance measuring device 31 has a spherical portion in contact with the moving blade 15, durability against contact with the moving blade 15 can also be improved.

  Note that the measurement device housing 32, the displacement meter support 34, the sphere support 36, and the measurement device support 37 in the initial clearance measurement device 31 all have a cylindrical shape, and a measurement opening into which the initial clearance measurement device 31 is inserted. Although 21 is set as the structure currently formed in circular shape, it is not limited to this. For example, the outer surfaces of the measurement device housing 32, the displacement meter support 34, the sphere support 36, and the measurement device support 37 all have a rectangular shape, and the measurement opening 21 is similarly formed in a rectangular shape. It is good also as a structure.

[Embodiment 2]
The structure of the initial clearance measuring device 31 according to the second embodiment will be described focusing on differences from the initial clearance measuring device 31 according to the first embodiment. The measuring method by the initial clearance measuring device 31 according to the second embodiment is the same as the measuring method by the initial clearance measuring device 31 according to the first embodiment.

(Structure of initial clearance measuring device 31)
FIG. 5-1 shows that the inner diameter of the second step portion of the sphere support is larger than the diameter of the sphere in the structure of the detection side portion of the initial clearance measuring device, and the inner surface of the second step portion from the outer surface of the sphere. FIG. 5B is a diagram illustrating a measurement error that occurs when the sphere of the initial clearance measuring device contacts the tip of the moving blade. 6A is a diagram illustrating a configuration of a contact of the initial clearance measuring device according to the second embodiment, and FIG. 6-2 is a diagram illustrating a state where a sphere of the initial clearance measuring device is in contact with a tip of a moving blade. is there. The structure of the initial clearance measuring device 31 according to the second embodiment will be described with reference to FIGS. 5-1, 5-2, 6-1 and 6-2.

  As shown in FIG. 5B, when the moving blade 15 rotates and makes point contact with the sphere 35, the sphere 35 moves from the tip of the moving blade 15 toward the communication side in the axial direction of the contact rod 33 a. And a force F that is a resultant force of the point contact and the frictional force. The spherical body 35 is displaced by the force F to the communication side in the axial direction of the contact rod 33a, and is displaced in the direction of the frictional force due to the point contact between the moving blade 15 and the spherical body 35. Due to the displacement of the direction of the frictional force of the sphere 35, the tip of the contactor 33 b comes into point contact with a position displaced from the top of the sphere 35 on the communication side. Due to this point contact deviation, as shown in FIG. 5B, an error E occurs between the axial displacement of the contact rod 33a of the sphere 35 and the displacement of the contact 33b in the axial direction. As a result, the displacement L1 in the axial direction of the contact 33b detected by the displacement meter 33 is a value containing the error E, and is a value different from the displacement of the spherical body 35 in the axial direction. In this case, the displacement meter 33 may not be able to measure an accurate initial clearance (displacement in the axial direction of the contact rod 33a of the sphere 35).

  FIG. 6A illustrates the structure of the detection side portion of the initial clearance measuring device 31 according to the second embodiment. As shown in FIG. 6A, in the second embodiment, a cylindrical contact 33c is attached to the tip of the contact rod 33a instead of the contact 33b of the first embodiment. The end surface on the detection side of the contact 33c is a plane perpendicular to the axial direction of the contact rod 33a, and the plane makes point contact with the sphere 35. Therefore, even if the sphere 35 receives the force F described above from the moving blade 15 and is displaced in the direction of the frictional force due to the point contact between the moving blade 15 and the sphere 35, the end surface on the detection side of the contact 33c is always Point contact is made with the top of the sphere 35 on the communication side. As a result, since the displacement in the axial direction of the contact rod 33a of the sphere 35 and the displacement in the axial direction of the contact 33c are the same displacement L2, the displacement meter 33 can accurately measure the initial clearance. Is possible.

  As described above, the initial clearance measuring device 31 uses the contact of the displacement meter 33 as a cylindrical object whose detection-side end surface has a plane perpendicular to the axial direction of the contact rod 33a. Even when the force F is received, the end surface on the detection side of the cylindrical contact always makes point contact with the top of the sphere 35 on the communication side. As a result, the displacement meter 33 has the same displacement in the axial direction of the contact rod 33a of the spherical body 35 as the displacement in the axial direction of the contact, so that an accurate initial clearance can be measured.

  In addition, although the contactor 33c was made into the cylindrical shape thing, it is not limited to this. That is, even when the sphere 35 receives the force F from the moving blade 15 and is displaced in the direction of the frictional force due to the point contact between the moving blade 15 and the sphere 35, the contact that always makes point contact with the top of the sphere 35 on the communication side. Any shape having a plane perpendicular to the axial direction of the rod 33a may be used.

[Embodiment 3]
The initial clearance measuring device 31 and the measuring method according to the third embodiment will be described focusing on differences from the initial clearance measuring device 31 and the measuring method according to the first embodiment.

(Structure of initial clearance measuring device 31)
FIG. 7A is a diagram illustrating adjustment of the allowance of the sphere by the hole diameter adjusting mechanism of the third embodiment, and FIG. 7B is a diagram in which the allowance of the sphere is adjusted to the maximum by the hole adjusting mechanism of the third embodiment. It is a figure which shows a state. The structure of the initial clearance measuring device 31 according to the third embodiment will be described with reference to FIG.

  As shown in FIG. 7A, in the initial clearance measuring device 31 according to the third embodiment, a spherical support hole 36c is opened on the detection-side end surface of the second step portion 36e of the spherical support 36. A ring-shaped hole diameter adjusting mechanism 38 is installed on the inner surface side of the end surface. The sphere 35 is supported inside the sphere support 36 in a state where the sphere 35 is in contact with a central hole (a sphere support adjustment hole 38 g described later) of the hole diameter adjustment mechanism 38.

  The hole diameter adjusting mechanism 38 has a mechanism for adjusting the hole diameter of the spherical body support adjusting hole 38g. FIG. 7A shows a state in which the sphere support adjusting hole 38g of the hole diameter adjusting mechanism 38 is reduced in diameter, and the protrusion of the second stepped portion 36e of the sphere 35 from the detection side end face is P1. Yes. Further, in FIG. 7-2, the sphere support adjusting hole 38g of the hole diameter adjusting mechanism 38 is enlarged to the maximum, and the protrusion of the second step portion 36e of the sphere 35 from the end surface on the detection side is P2 (> P1). The state is shown. As described above, the hole diameter adjusting mechanism 38 adjusts the hole diameter of the sphere support adjusting hole 38g, thereby adjusting the protrusion of the second step portion 36e of the sphere 35 from the end surface on the detection side.

(Structure of hole diameter adjusting mechanism 38)
8A is a diagram illustrating an example of the structure of the hole diameter adjusting mechanism of the third embodiment, and FIG. 8B is a diagram illustrating a blade body of the hole diameter adjusting mechanism of the third embodiment. 3 is a view showing a hole diameter adjusting ring of the hole diameter adjusting mechanism of the third embodiment, and FIG. 8-4 shows a state in which the diameter of the sphere support adjusting hole of the hole diameter adjusting mechanism of the third embodiment is adjusted. FIG. Hereinafter, an example of the structure of the hole diameter adjusting mechanism 38 will be described with reference to FIGS.

  As shown in FIG. 8A, the hole diameter adjusting mechanism 38 includes a plurality of (six in FIG. 8-1) blade bodies 38a having a curved shape and a circular ring-shaped hole diameter adjusting ring 38d. Has been. As shown in FIG. 8B, the blade body 38a has a long hole 38b and a fulcrum pin hole 38c. Further, as shown in FIG. 8-3, the hole diameter adjusting ring 38d has a circular ring hole 38f opened at the center, and a plurality (six in FIG. 8-3) of the ring shape in the circumferential direction. A pin 38e is erected.

  Further, the inner surface of the end surface of the second step portion 36e of the sphere support 36 where the sphere support holes 36c are opened has a plurality at equal intervals in the circumferential direction and toward the communication side (in FIG. 8A). Six) support pins 36f are provided upright. Then, as shown in FIG. 8A, a hole diameter adjusting ring 38d is placed on the inner surface of the second step portion 36e, and the support pin 36f is inserted into the fulcrum pin holes 38c of the plurality of blade bodies 38a. In addition, the pin 38e is inserted into the long hole 38b and installed so as to overlap each other. Thus, by installing each blade body 38a, a spherical body support adjustment hole 38g as an adjustment hole is formed by the inner periphery of the curved shape of each blade body 38a as shown in FIG. The

  The hole diameter adjusting mechanism 38 rotates the hole diameter adjusting ring 38d, whereby the pin 38e moves in the rotation direction and slides in the elongated hole 38b. When the pin 38e slides in the long hole 38b, each blade body 38a rotates around the fulcrum pin hole 38c through which the support pin 36f is inserted. Then, by rotating each blade body 38a, the diameter of the spherical body support adjusting hole 38g formed by the inner peripheral edge of the curved shape of each blade body 38a is adjusted.

  Specifically, as shown in FIG. 8A, when the hole diameter adjusting ring 38d rotates counterclockwise in the paper surface, each pin 38e of the hole diameter adjusting ring 38d slides inside the long hole 38b, and each blade The body 38a rotates to the right in the paper view. Thereby, the spherical body support adjusting hole 38g is expanded in diameter. FIG. 8A shows a case where the sphere support adjustment hole 38g is expanded to the maximum, and the inner diameter of the sphere support adjustment hole 38g matches the inner diameter of the ring hole 38f of the hole diameter adjustment ring 38d. It shows the state.

  On the other hand, as shown in FIG. 8-4, when the hole diameter adjusting ring 38d rotates to the right in the paper view, each pin 38e of the hole diameter adjusting ring 38d slides in the long hole 38b, and each blade body 38a It rotates counterclockwise in the paper view. As a result, the diameter of the spherical body support adjusting hole 38g is reduced.

  In order to adjust the hole diameter of the spherical body support adjusting hole 38g of the hole diameter adjusting mechanism 38, it is necessary to rotate the hole diameter adjusting ring 38d. However, the hole diameter adjusting ring 38d may be manually rotated. A drive mechanism may be included, and the drive mechanism may adjust the diameter of the spherical body support adjustment hole 38g based on a control signal from a control device installed inside or outside the initial clearance measuring device 31. Further, when the control device is provided, an operation unit connected to the control device may be provided. In this case, the operator operates the operation unit via the control device and the drive mechanism. Thus, the hole diameter adjusting ring 38d may be rotated.

  Further, as shown in FIG. 8A, when the sphere support adjustment hole 38g is expanded to the maximum, the inner diameter of the sphere support adjustment hole 38g matches the inner diameter of the ring hole 38f of the hole diameter adjustment ring 38d. However, the present invention is not limited to this. That is, the hole diameter adjusting mechanism 38 may be configured such that the hole diameter when the spherical body support adjusting hole 38g is expanded to the maximum is smaller than the hole diameter of the ring hole 38f.

(Initial clearance measurement method using the initial clearance measuring device 31)
FIG. 9 is a flowchart illustrating an initial clearance measuring method according to the third embodiment. Hereinafter, an initial clearance measurement method will be described with reference to FIG.

(Step S1)
First, an operator who wants to measure the initial clearance starts the turning operation for the gas turbine 1. Then, the process proceeds to step S2.

(Step S2)
The operator inserts the initial clearance measurement device 31 into the measurement opening 21 of the casing 11 from the longitudinal detection side, and the support surface 37c of the measurement device support 37 of the initial clearance measurement device 31 is a flange portion. It pushes in until it contacts 22 measuring device support surface 22b. Then, the process proceeds to step S3.

(Step S3)
The operator confirms whether or not the displacement of the sphere 35 has been detected when all the moving blades 15 have contacted the sphere 35 with the displacement meter 33. If it is detected as a result of the confirmation, the process proceeds to step S4, and if no displacement of the sphere 35 is detected for some of the moving blades 15, or if no displacement of the sphere 35 is detected for all of the moving blades 15, Proceed to S5.

(Step S4)
The displacement meter 33 transmits the detected displacement information of the sphere 35 to the calculation unit 51 via the communication line 52. Based on the length of the portion of the initial clearance measuring device 31 that extends to the gas passage 17 and the displacement information received from the displacement meter 33, the calculation unit 51 determines the tip of each rotor blade 15 and the inside of the casing. The initial clearance with the wall surface 23 is calculated, and the initial clearance is stored. With the above procedure, the initial clearance is measured in the measurement opening 21 into which the initial clearance measuring device 31 is inserted.

(Step S5)
The operator pulls out the initial clearance measuring device 31 from the measurement opening 21 and rotates the hole diameter adjusting ring 38d of the hole diameter adjusting mechanism 38 to expand the diameter of the sphere support adjusting hole 38g. Increase Then, the operator inserts the initial clearance measuring device 31 into the measurement opening 21 again. Then, the process returns to step S3.

  The operator continues the turning operation of the gas turbine 1, inserts the initial clearance measuring device 31 into each of the plurality of measurement openings 21 formed in the casing 11, and measures the initial clearance shown in FIG. 9. To implement. Then, when all the measured initial clearances are within a predetermined tolerance, the operator determines that normal operation by high-speed rotation of the gas turbine 1 is possible, and starts the normal operation.

  As described above, the initial clearance measurement device 31 includes a drive mechanism that rotates the hole diameter adjustment ring 38d, and a control device is provided inside or outside the initial clearance measurement device 31 that controls the drive mechanism. When the operation unit is provided in the control device, the operator may increase the diameter of the spherical body support adjustment hole 38g by operating the operation unit. This eliminates the need to pull out the initial clearance measuring device 31 from the measurement opening 21, thereby improving work efficiency.

  Since the initial clearance measuring device 31 includes the hole diameter adjusting mechanism 38, the hole diameter of the sphere support adjusting hole 38g with which the sphere 35 abuts can be adjusted. As a result, when contact between the tips of all the moving blades 15 and the sphere 35 is not detected in a certain measurement opening 21, the diameter of the sphere support adjustment hole 38g is expanded to increase the size of the sphere 35. Since the adjustment can be made, contact with the sphere 35 can be detected for all the moving blades 15.

  Note that the configuration of the initial clearance measurement device 31 of the third embodiment as described above can also be applied to the initial clearance measurement device 31 of the second embodiment.

[Embodiment 4]
The structure of the initial clearance measuring device 31 according to the fourth embodiment will be described focusing on differences from the initial clearance measuring device 31 according to the first embodiment. Further, the measurement method by the initial clearance measurement device 31 according to the fourth embodiment will be described focusing on differences from the measurement method by the initial clearance measurement device 31 according to the third embodiment shown in FIG.

(Structure of initial clearance measuring device 31)
FIG. 10 is a cross-sectional view of a main part of the initial clearance measuring device according to the fourth embodiment. Hereinafter, the structure of the initial clearance measuring device 31 according to the fourth embodiment will be described with reference to FIG.

  The initial clearance measuring device 31 according to the fourth embodiment includes a measuring device housing 32, a displacement meter 33, an adjustment mechanism housing 39, a sphere 35, and a measuring device support 37.

  The measuring device casing 32 constitutes the outer shape of the cylindrical initial clearance measuring device 31. A stepped portion 32b having a reduced diameter is formed on the detection side portion of the outer surface of the measuring device casing 32, and a screwed fitting is provided on the inner surface of the stepped portion 32b as a stepped portion fitting portion. A joint portion 32c is formed. In addition, a threaded fitting portion 32d is formed on the outer surface of the step portion 32b.

  The adjustment mechanism housing 39 is a cylindrical object that supports the main body of the displacement meter 33 and supports the sphere 35 that makes point contact with the tip of the moving blade 15 when the initial clearance is measured. A support portion 39a having a reduced diameter is formed at a predetermined position on the inner surface of the adjustment mechanism housing 39, and the displacement meter 33 is supported by being in contact with an end surface on the communication side of the support portion 39a. . Further, the contact rod 33a extends from the detection side portion of the displacement meter 33 supported by the support portion 39a toward the detection side. The axial center line of the contact rod 33 a substantially coincides with the axial center line of the measuring device housing 32. Further, a contact 33b having a convex shape toward the detection side is attached as a support fitting portion to the detection-side tip of the contact rod 33a. In addition, a circular sphere support hole 39c where the axial center line of the contact rod 33a intersects the center is opened on the detection-side end face of the adjustment mechanism housing 39, and the sphere 35 has a peripheral edge of the sphere support hole 39c. It is supported inside the adjustment mechanism housing 39 while being in contact with the portion. In addition, a fitting portion 39b that is threaded is formed on the outer surface of the adjustment mechanism housing 39 over a predetermined range in the direction from the communication side to the detection side. Moreover, the measuring device housing 32 and the adjustment mechanism housing 39 are connected by fitting the fitting portion 32c of the measuring device housing 32 and the fitting portion 39b. The communication side end of the adjustment mechanism housing 39 protrudes from the communication side end of the measuring device housing 32. Then, by rotating the protrusion, the adjustment mechanism housing 39 is detected or communicated in the positional relationship with the measuring device housing 32 via the fitting portion 32c and the fitting portion 39b. Can be moved to the side. In this case, the movement range of the adjustment mechanism housing 39 is determined by the longitudinal range of the adjustment mechanism housing 39 of the fitting portion 39 b formed on the outer surface of the adjustment mechanism housing 39.

  The measuring device support 37 is fitted to the measuring device housing 32 and, when the initial clearance measuring device 31 is inserted into the measuring opening 21 of the casing 11, comes into contact with the flange portion 22 to measure the initial clearance. It is a cylindrical object that supports the entire device 31. On the inner surface of the measuring device support 37, a fitting portion 37a in which a screw is cut is formed. Further, a support surface 37c that contacts the flange portion 22 is formed on the detection side of the measurement device support 37, and an insertion hole 37b through which the measurement device housing 32 is inserted is opened in the measurement device support 37. Yes. The measuring device support 37 is connected to the measuring device housing 32 by inserting the measuring device housing 32 into the insertion hole 37b as described above and fitting the fitting portion 32d and the fitting portion 37a. Is done.

(Initial clearance measurement method using the initial clearance measuring device 31)
Next, with reference to FIG. 9 of the third embodiment, the initial clearance measuring method of the fourth embodiment will be described focusing on differences from the third embodiment.

  The procedure of steps S1 to S4 shown in FIG. 9 in the third embodiment is the same in the fourth embodiment.

(Step S5)
The operator moves the adjustment mechanism housing 39 to the detection side by rotating the communication side portion of the adjustment mechanism housing 39 protruding from the communication end of the measurement device housing 32 of the initial clearance measurement device 31. Then, the top of the spherical body 35 on the detection side is brought close to the tip of the moving blade 15. Then, the process returns to step S3.

  The operator continues the turning operation of the gas turbine 1 and inserts the initial clearance measuring device 31 into each of the plurality of measurement openings 21 formed in the casing 11 to measure the initial clearance. To do. Then, when all the measured initial clearances are within a predetermined tolerance, the operator determines that normal operation by high-speed rotation of the gas turbine 1 is possible, and starts the normal operation.

  As described above, the adjustment mechanism housing 39 can be moved to the detection side by rotating the communication side portion of the adjustment mechanism housing 39 protruding from the communication side end of the measurement device housing 32. it can. As a result, when contact between the tip of all the moving blades 15 and the sphere 35 is not detected in a certain measurement opening 21, the top on the detection side of the sphere 35 can be brought close to the tip of the moving blade 15. Contact with the sphere 35 can be detected for all the moving blades 15.

  Further, since the operator can perform the operation of moving the adjustment mechanism housing 39 to the detection side without pulling out the initial clearance measuring device 31 from the measurement opening 21, it is possible to improve the work efficiency. .

  The configuration of the hole diameter adjusting mechanism 38 of the initial clearance measuring device 31 according to the third embodiment can also be applied to the initial clearance measuring device 31 according to the fourth embodiment.

[Embodiment 5]
A measurement method by the initial clearance measurement device 31 according to the fifth embodiment will be described focusing on differences from the measurement method 1 by the initial clearance measurement device 31 according to the third embodiment. The structure of the initial clearance measuring device 31 according to the fifth embodiment is the same as that of the initial clearance measuring device 31 according to the first embodiment.

(Initial clearance measurement method using the initial clearance measuring device 31)
FIG. 11A is a cross-sectional view of a main part in a state where a shim is installed in the initial clearance measuring device according to the fifth embodiment, and FIG. 11B is a state where the shim is removed in the initial clearance measuring device according to the fifth embodiment. FIG. With reference to FIGS. 11-1 and 11-2 and FIG. 9 of the third embodiment, the initial clearance measuring method of the fifth embodiment will be described with a focus on differences from the third embodiment.

  The procedure of steps S1, S3 and S4 shown in FIG. 9 in the third embodiment is the same in the fifth embodiment.

(Step S2)
As shown in FIG. 11A, the worker installs a circular ring-shaped shim 40 so as to come into contact with the inner surface of the support surface 37 c in the measurement device support 37. Next, the operator inserts the measuring device support 37 on which the shim 40 is installed into the insertion hole 37b through the second step portion 36e, and the communication side end surface of the shim 40 detects the first step portion 36d. The fitting portion 36 b and the fitting portion 37 a are fitted and connected to the spherical body support 36 until they abut against the side end face. By such an operation, the support surface 37c of the measurement device support 37 is moved to the detection side by the thickness of the shim 40. Then, the operator inserts the initial clearance measurement device 31 into the measurement opening 21 of the casing 11 from the longitudinal detection side, and the support surface 37c of the measurement device support 37 of the initial clearance measurement device 31 is Push in until the measuring device support surface 22b of the flange portion 22 abuts. Then, the process proceeds to step S3.

(Step S5)
The operator pulls out the initial clearance measuring device 31 from the measurement opening 21 and removes the measuring device support 37 from the sphere support 36. Next, the operator removes the shim 40 installed on the measuring device support 37 and installs a shim thinner than the shim 40 on the measuring device support 37. The operator again inserts the measuring device support 37 into the insertion hole 37b through the second step portion 36e, and the communication-side end surface of the replaced shim becomes the detection-side end surface of the first step portion 36d. The fitting portion 36b and the fitting portion 37a are fitted and connected to the sphere support 36 until they abut. Alternatively, the operator removes the shim previously installed on the measurement device support 37 and connects the measurement device support 37 to the sphere support 36 (see FIG. 11-2). Then, the operator inserts the initial clearance measuring device 31 into the measurement opening 21 again. Thereby, the length of the extension part to the gas passage 17 of the initial clearance measuring device 31 can be lengthened. Then, the process returns to step S3.

  The operator continues the turning operation of the gas turbine 1, inserts the initial clearance measuring device 31 into each of the plurality of measurement openings 21 formed in the casing 11, and measures the initial clearance shown in FIG. 9. I do. Then, when all the measured initial clearances are within a predetermined tolerance, the operator determines that normal operation by high-speed rotation of the gas turbine 1 is possible, and starts the normal operation.

  As described above, the initial clearance measuring device 31 is adjusted to the gas passage 17 of the initial clearance measuring device 31 by adjusting the thickness of the shim installed on the measuring device support 37 or by removing the shim itself. The length of the extended portion of the is adjusted. Accordingly, when contact between the tip of all the moving blades 15 and the sphere 35 is not detected in a certain measurement opening 21, the length of the extended portion can be adjusted. Contact with the sphere 35 can be detected.

  The configuration of the hole diameter adjusting mechanism 38 of the initial clearance measuring device 31 according to the third embodiment can also be applied to the initial clearance measuring device 31 according to the fifth embodiment.

[Embodiment 6]
The structure of the initial clearance measuring device 31 according to the sixth embodiment will be described focusing on differences from the initial clearance measuring device 31 according to the fourth embodiment. Further, the measurement method by the initial clearance measurement device 31 according to the sixth embodiment will be described focusing on differences from the measurement method by the initial clearance measurement device 31 according to the third embodiment shown in FIG.

(Structure of initial clearance measuring device 31)
FIG. 12 is a cross-sectional view of a main part of the initial clearance measuring device according to the sixth embodiment. Hereinafter, the structure of the initial clearance measuring device 31 according to the sixth embodiment will be described with reference to FIG.

  The initial clearance measurement device 31 according to the sixth embodiment includes a measurement device housing 32, a pressure detector 41, an adjustment mechanism housing 39, a sphere 35, and a measurement device support 37.

  The adjustment mechanism housing 39 is a cylindrical object that supports the main body of the pressure detector 41 and supports the sphere 35 that makes point contact with the tip of the moving blade 15 when the initial clearance is measured. A support portion 39a having a reduced diameter is formed at a predetermined position on the inner surface of the adjustment mechanism housing 39, and the pressure detector 41 is supported by being in contact with an end surface on the communication side of the support portion 39a. ing. Moreover, the pressure-sensitive element connection line 41a extends toward the detection side from the detection side portion of the pressure detector 41 supported by the support portion 39a. Further, the detection-side end of the pressure-sensitive element connection line 41a is connected to the pressure-sensitive element 41b. In addition, a circular sphere support hole 39c where the axial center line of the adjustment mechanism housing 39 intersects with the center is opened on the end surface on the detection side of the adjustment mechanism housing 39, and the sphere 35 has the sphere support hole 39c. Is supported in the adjustment mechanism housing 39 in a state of being in contact with the peripheral edge portion. Further, the pressure sensitive element 41 b is fixed at a position in the measuring device housing 32 that comes into contact with the top of the spherical body 35 on the communication side. In addition, a fitting portion 39b that is threaded is formed on the outer surface of the adjustment mechanism housing 39 over a predetermined range in the direction from the communication side to the detection side. Moreover, the measuring device housing 32 and the adjustment mechanism housing 39 are connected by fitting the fitting portion 32c of the measuring device housing 32 and the fitting portion 39b. In addition, the communication-side end of the adjustment mechanism housing 39 protrudes from the communication-side end of the measurement device housing 32. Then, by rotating the protruding portion, the adjusting mechanism housing 39 is moved to the detection side or the detection device in the positional relationship with the measuring device housing 32 via the fitting portion 32c and the fitting portion 39b. It can be moved to the communication side. In this case, the movement range of the adjustment mechanism housing 39 is determined by the longitudinal range of the adjustment mechanism housing 39 of the fitting portion 39 b formed on the outer surface of the adjustment mechanism housing 39. Further, a scale is engraved on the outer surface of the adjustment mechanism housing 39 on the communication side, and the amount of movement of the adjustment mechanism housing 39 to the detection side or the communication side can be measured.

  Other structures are the same as the structure of the initial clearance measuring device 31 according to the fourth embodiment.

(Initial clearance measurement method using the initial clearance measuring device 31)
Next, with reference to FIG. 9 of the third embodiment, the initial clearance measuring method of the sixth embodiment will be described focusing on differences from the third embodiment.

  The procedure of steps S1 and S2 shown in FIG. 9 in the third embodiment is the same in the sixth embodiment.

(Step S3)
The operator confirms whether or not all the moving blades 15 are in contact with the sphere 35 by the pressure detector 41 and the pressure sensitive element 41b. If it is detected as a result of the confirmation, the process proceeds to step S4, and contact with the sphere 35 is not detected for some of the moving blades 15 or contact with the sphere 35 is not detected for all of the moving blades 15. The process proceeds to step S5.

(Step S4)
The pressure-sensitive element 41b detects that the sphere 35 is in contact with the tip of the rotor blade 15 and receives pressure from the sphere 35, and the detected information is sent to the pressure detector via the pressure-sensitive element connection line 41a. 41. The pressure detector 41 transmits the received detection information to the calculation unit 51 via the communication line 52. When the calculation unit 51 receives the detection information, the calculation unit 51 measures the length of the extension portion of the first initial clearance measurement device 31 that is already known and the scale that is engraved on the outer surface of the adjustment mechanism housing 39 on the communication side. Based on the amount of movement of the mechanism housing 39 to the detection side, an initial clearance is calculated and the initial clearance is stored. In this case, the pressure detector 41 and the pressure sensitive element 41b detect only whether or not the pressure is received from the sphere 35, and cannot detect the displacement of the sphere 35. Therefore, the initial clearance calculated by the calculation unit 51 is an approximate value of the clearance between the tip of each rotor blade 15 and the casing inner wall surface 23. By the procedure described above, the initial clearance is measured in the measurement opening 21 into which the initial clearance measuring device 31 is inserted.

  The pressure sensitive element 41b is connected to the pressure detector 41 via the pressure sensitive element connection line 41a. However, the pressure sensitive element 41b is not limited to this, and the pressure sensitive element 41b is connected to the pressure sensitive element connection line 41a. It is good also as a structure connected directly to the calculating part 51 by the line 41a or the communication line 52. FIG.

(Step S5)
The operator moves the adjustment mechanism housing 39 to the detection side by rotating the communication side portion of the adjustment mechanism housing 39 protruding from the communication end of the measurement device housing 32 of the initial clearance measurement device 31. Then, the top of the spherical body 35 on the detection side is brought close to the tip of the moving blade 15. In addition, the operator measures the amount of movement of the adjustment mechanism housing 39 to the detection side by a scale carved on the outer surface of the adjustment mechanism housing 39 on the communication side, and inputs it to the calculation unit 51. The movement amount may be input to the calculation unit 51, for example, when an operation unit is connected to the calculation unit 51 and an operator operates the operation unit. Then, the process returns to step S3.

  The operator continues the turning operation of the gas turbine 1, inserts the initial clearance measuring device 31 into each of the plurality of measurement openings 21 formed in the casing 11, and measures the initial clearance by the method described above. To do. Then, when all the measured initial clearances are within a predetermined tolerance, the operator determines that normal operation by high-speed rotation of the gas turbine 1 is possible, and starts the normal operation.

  The adjustment mechanism housing 39 is configured to be able to rotate the communication-side protrusion and move it to the detection side, measure the amount of movement, and use the pressure-sensitive element 41b to Contact with the sphere 35 can be detected. As a result, when contact between the tip of all the moving blades 15 and the sphere 35 is not detected in a certain measurement opening 21, the top on the detection side of the sphere 35 can be brought close to the tip of the moving blade 15. Contact with the sphere 35 can be detected for all the moving blades 15.

[Embodiment 7]
The structure of the initial clearance measuring device 31 according to the seventh embodiment will be described focusing on differences from the initial clearance measuring device 31 according to the fourth embodiment. Further, the measurement method by the initial clearance measurement device 31 according to the seventh embodiment will be described focusing on differences from the measurement method by the initial clearance measurement device 31 according to the third embodiment shown in FIG.

(Structure of initial clearance measuring device 31)
FIG. 13-1 is a cross-sectional view of a main part of the initial clearance measuring device according to the seventh embodiment, and FIG. 13-2 is an operation explanatory diagram of the initial clearance measuring device according to the seventh embodiment. The structure of the initial clearance measuring device 31 according to the seventh embodiment will be described with reference to FIGS. 13-1 and 13-2.

  As illustrated in FIG. 13A, the initial clearance measuring device 31 according to the seventh embodiment includes a measuring device housing 32, a current detector 42, thin plates 42 b and 42 c, an adjustment mechanism housing 39, and a measuring device support 37. ing.

  The adjustment mechanism housing 39 is a cylindrical object that supports the main body of the energization detector 42. A support portion 39a having a reduced diameter is formed at a predetermined position on the inner surface of the adjustment mechanism housing 39, and an energization detector 42 is in contact with and supported by the communication-side end surface of the support portion 39a. Yes. In addition, two connection lines 42a extend toward the detection side from the detection side portion of the energization detector 42 supported by the support portion 39a. The thin plate 42b is connected to the end of one of the two connection lines 42a, and the end of the other connection line 42a is connected to the end of the measuring device housing 32 in the axial direction. The thin plate 42c whose length is shorter than the thin plate 42b is connected. In addition, a thin plate support hole 39d is opened on the detection-side end surface of the adjustment mechanism housing 39, and the thin plate support 42d is fixed in a state of being in contact with the inner surface of the thin plate support hole 39d. The thin plates 42b and 42c are supported by the thin plate support 42d and extend from the thin plate support hole 39d toward the detection side. In addition, a fitting portion 39b that is threaded is formed on the outer surface of the adjustment mechanism housing 39 over a predetermined range in the direction from the communication side to the detection side. Moreover, the measuring device housing 32 and the adjustment mechanism housing 39 are connected by fitting the fitting portion 32c of the measuring device housing 32 and the fitting portion 39b. In addition, the communication-side end of the adjustment mechanism housing 39 protrudes from the communication-side end of the measurement device housing 32. Then, by rotating the protruding portion, the adjusting mechanism housing 39 is moved to the detection side or the detection device in the positional relationship with the measuring device housing 32 via the fitting portion 32c and the fitting portion 39b. It can be moved to the communication side. In this case, the movement range of the adjustment mechanism housing 39 is determined by the longitudinal range of the adjustment mechanism housing 39 of the fitting portion 39 b formed on the outer surface of the adjustment mechanism housing 39. Further, a scale is engraved on the outer surface of the adjustment mechanism housing 39 on the communication side, and the amount of movement of the adjustment mechanism housing 39 to the detection side or the communication side can be measured.

  Other structures are the same as the structure of the initial clearance measuring device 31 according to the fourth embodiment.

(Initial clearance measurement method using the initial clearance measuring device 31)
Next, with reference to FIGS. 13-1 and 13-2 and FIG. 9 of the third embodiment, the initial clearance measuring method of the seventh embodiment will be described focusing on differences from the third embodiment.

  The procedure of steps S1 and S2 shown in FIG. 9 in the third embodiment is the same in the seventh embodiment.

(Step S3)
The operator confirms whether or not all the moving blades 15 are in contact with the sphere 35 by the energization detector 42 and the thin plates 42b and 42c. If it is detected as a result of the confirmation, the process proceeds to step S4, and contact with the sphere 35 is not detected for some of the moving blades 15 or contact with the sphere 35 is not detected for all of the moving blades 15. The process proceeds to step S5.

(Step S4)
As shown in FIG. 13-2, when the thin plate 42b comes into contact with the tip of the moving blade 15, the tip moves to the thin plate 42c side and comes into contact with the thin plate 42c. When the thin plate 42b and the thin plate 42c come into contact with each other, a current flows between the two connection lines 42a through the thin plates 42b and 42c, and the energization state is detected by the energization detector 42. When the energization detector 42 detects energization between the two connection lines 42 a, the energization detector 42 transmits the detection information to the calculation unit 51 via the communication line 52. When the calculation unit 51 receives the detection information, the calculation unit 51 measures the length of the extension portion of the first initial clearance measurement device 31 that is already known, and a scale carved on the outer surface of the adjustment mechanism housing 39 on the communication side. Based on the amount of movement of the adjustment mechanism housing 39 to the detection side, the initial clearance is calculated, and the initial clearance is stored. In this case, the energization detector 42 and the thin plates 42 b and 42 c detect only the contact between the thin plate 42 b and the moving blade 15, and cannot detect the displacement of the sphere 35. Therefore, the initial clearance calculated by the calculation unit 51 is an approximate value of the clearance between the tip of each rotor blade 15 and the casing inner wall surface 23. By the above-described procedure, the initial clearance in the measurement opening 21 into which the initial clearance measuring device 31 is inserted is measured.

(Step S5)
The operator moves the adjustment mechanism housing 39 to the detection side by rotating the communication side portion of the adjustment mechanism housing 39 protruding from the communication end of the measurement device housing 32 of the initial clearance measurement device 31. Then, the top of the spherical body 35 on the detection side is brought close to the tip of the moving blade 15. In addition, the operator measures the amount of movement of the adjustment mechanism housing 39 to the detection side by a scale carved on the outer surface of the adjustment mechanism housing 39 on the communication side, and inputs it to the calculation unit 51. The input of the movement amount to the calculation unit 51 may be performed by, for example, an operation unit connected to the calculation unit 51 and an operator operating the operation unit. Then, the process returns to step S3.

  The operator continues the turning operation of the gas turbine 1 and inserts the initial clearance measuring device 31 into each of the plurality of measurement openings 21 formed in the casing 11 to measure the initial clearance. To do. Then, when all the measured initial clearances are within a predetermined tolerance, the operator determines that normal operation by high-speed rotation of the gas turbine 1 is possible, and starts the normal operation.

  The communication side protrusion of the adjustment mechanism housing 39 can be rotated and moved to the detection side, the amount of movement can be measured, and the moving blade can be measured by the energization detector 42 and the thin plates 42b and 42c. The contact between the 15 tips and the thin plate 42b can be detected. As a result, when contact between the tip of all the moving blades 15 and the sphere 35 is not detected in a certain measurement opening 21, the top on the detection side of the sphere 35 can be brought close to the tip of the moving blade 15. Contact with the sphere 35 can be detected for all the moving blades 15.

[Eighth embodiment]
The initial clearance measuring device 31 and the measuring method according to the eighth embodiment will be described focusing on differences from the initial clearance measuring device 31 and the measuring method according to the first embodiment.

(Structure of initial clearance measuring device 31)
FIG. 14 is a cross-sectional view of a main part of the initial clearance measuring device according to the eighth embodiment. Hereinafter, the structure of the initial clearance measuring device 31 according to the eighth embodiment will be described with reference to FIG.

  The initial clearance measuring device 31 according to the eighth embodiment includes a measuring device housing 32, a displacement meter 33, a displacement meter support 34, a cylindrical body 35a, and a cylindrical body support 43. Among these, the structures of the measurement device casing 32, the displacement meter 33, and the displacement meter support 34 are the same as those of the initial clearance measurement device 31 according to the first embodiment.

  The columnar support 43 is a cylindrical object that supports the columnar body 35a that is in surface contact with the tip of the rotor blade 15 when the initial clearance is measured, and the communication side portion of the inner surface of the cylinder is threaded. A fitting portion 43a is formed. When the fitting portion 34b of the displacement meter support 34 and the fitting portion 43a are fitted, the displacement meter support 34 and the columnar support 43 are connected. In addition, a stepped portion 43 c having a reduced diameter is formed on the detection side portion of the outer surface of the cylindrical columnar support 43. A circular cylindrical body support hole 43b in which the axial center line of the contact rod 33a intersects the center is opened on the end surface on the detection side of the stepped portion 43c. It is supported inside the cylindrical body support 43 in a state of being in contact with the portion. Specifically, the cylindrical body 35a has a two-stage shape in which the detection side has a reduced diameter, the detection side portion having a small diameter is inserted into the cylindrical body support hole 43b, and the communication side portion having a large diameter is the cylindrical body. It is supported on the inner surface of the support hole 43b. With such a structure, the cylindrical body 35a has a protrusion extending in a convex shape from the end surface on the detection side of the stepped portion 43c. Further, the end face on the communication side of the cylindrical body 35a is in point contact with the tip of the contact 33b of the displacement meter 33 and is urged by the contact 33b.

(Initial clearance measurement method using the initial clearance measuring device 31)
Next, an initial clearance measurement method will be described.

  First, an operator who wants to measure the initial clearance puts the gas turbine 1 in an operation stop state.

  Next, the operator inserts the initial clearance measuring device 31 into the measurement opening 21 of the casing 11 from the longitudinal detection side. As the initial clearance measuring device 31 moves in the measurement opening 21, the stepped portion 43c of the cylindrical body support 43 is inserted into the hole of the ring-shaped flange portion 22 and is in sliding contact with the flange inner wall surface 22a. The end surface on the detection side of the reduced diameter portion of the cylindrical body support 43 abuts on the measurement device support surface 22b of the flange portion 22. At this time, at least a part of the stepped portion 43c protrudes into the gas passage 17, or all of the protruding portion from the end surface on the detection side of the stepped portion 43c of the cylindrical body 35a enters the gas passage 17. To be in a state. As described above, the portion of the stepped portion 43c and the cylindrical body 35a that protrudes from the measurement opening 21 into the gas passage 17 is referred to as an “extension portion” of the initial clearance measuring device 31 as in the first embodiment. . In this way, the initial clearance measuring device 31 is installed in the measurement opening 21. At this time, the length from the casing inner wall surface 23 (the end surface on the gas passage 17 side of the flange portion 22) to the end surface on the detection side of the cylindrical body 35a is described as “the length of the extending portion” as in the first embodiment. . The length of the extended portion of the initial clearance measuring device 31 is measured in advance and is known in advance.

  Thus, when the initial clearance measuring device 31 is installed in the measurement opening 21, the tip of the moving blade 15 comes into surface contact with the cylindrical body 35a. The moving blade 15 in surface contact with the cylindrical body 35a displaces the cylindrical body 35a in the direction of the communication side, and accordingly, the contact 33b is also displaced. The displacement meter 33 detects the amount of displacement of the spherical body 35 and the contact 33b by the moving blade 15 in surface contact with the cylindrical body 35a. The displacement meter 33 that has detected the displacement of the sphere 35 and the contact 33 b by the moving blade 15 transmits the displacement information to the calculation unit 51 via the communication line 52. The calculation unit 51 that has received the displacement information subtracts the displacement of the cylindrical body 35a that is in surface contact with the moving blade 15 from the known length of the extended portion, thereby obtaining the tip of the moving blade 15 and the inside of the casing. The initial clearance with the wall surface 23 is calculated, and this initial clearance is stored.

  The operator similarly measures the initial clearance for each moving blade 15 corresponding to the measurement opening 21 in which the initial clearance measuring device 31 is installed. At this time, the operator positions the rotor 12 of the gas turbine 1 with a motor so that the tip of the moving blade 15 for which the initial clearance is not measured faces the measurement opening 21. Further, the operator inserts the initial clearance measuring device 31 into each of the plurality of measurement openings 21 and measures the initial clearance in the same procedure as described above. Then, when all the measured initial clearances are within a predetermined tolerance, the operator determines that normal operation by high-speed rotation of the gas turbine 1 is possible, and starts the normal operation.

  As shown in the configuration of the initial clearance measuring device 31 and the measuring method, since the contact method in which the cylindrical body 35a is brought into surface contact with the moving blade 15 and the displacement of the cylindrical body 35a is measured, the gas turbine 1 is stopped. In this case, the initial clearance can be measured.

  In addition, although the initial clearance measuring device 31 and the measuring method thereof in the above-described first to eighth embodiments have been described for the gas turbine, the present invention is not limited to this, for example, other rotating machines such as a steam turbine. Is also applicable.

  As mentioned above, although Embodiment 1-8 was demonstrated, Embodiment 1-8 is not limited by the content mentioned above. In addition, the constituent elements of Embodiments 1 to 8 described above include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the above-described components can be appropriately combined. In addition, various omissions, substitutions, and changes of the components can be made without departing from the spirit of the first to eighth embodiments.

DESCRIPTION OF SYMBOLS 1 Gas turbine 11 Casing 12 Rotor 13 Bearing 14 Rotor disk 15 Rotor blade 16 Stator blade 17 Gas passage 18 Combustor 19 Exhaust port 21 Measurement opening 21a Opening inner wall surface 22 Flange portion 22a Flange portion inner wall surface 22b Measuring device support surface 23 Casing Inner wall surface 31 Initial clearance measuring device 32 Measuring device housing 32a Fitting portion 32b Step portion 32c, 32d Fitting portion 33 Displacement meter 33a Contact rod 33b, 33c Contact 34 Displacement meter support 34a, 34b Fitting portion 35 Sphere 35a Cylindrical body 36 Spherical body support body 36a, 36b Fitting part 36c Spherical body support hole 36d First step part 36e Second step part 36f Support point pin 37 Measuring device support body 37a Fitting part 37b Insertion hole 37c Support surface 38 Hole diameter Adjustment mechanism 38a Blade 38b Slot 38c Support point Hole 38d hole diameter adjustment ring 38e pin 38f ring hole 38g sphere support adjustment hole 39 adjustment mechanism housing 39a support portion 39b fitting portion 39c sphere support hole 39d thin plate support hole 40 shim 41 pressure detector 41a pressure sensing element connection line 41b Pressure sensing element 42 Energization detector 42a Connection line 42b, 42c Thin plate 42d Thin plate support body 43 Cylindrical body support body 43a Fitting part 43b Cylindrical body support hole 43c Step part 51 Calculation part 52 Communication line E Error F force L1, L2 Displacement P1 , P2

Claims (10)

A clearance measurement system for measuring the clearance between the tip of a moving blade fixed in parallel to the outer periphery of a rotor rotatably supported in the turbine and the inner wall surface of the turbine casing. Because
A casing having a cylindrical shape;
A displacement meter having a main body disposed in the housing, a rod extending in the axial direction of the housing from the detection side portion of the main body, and a contact attached to the tip of the rod;
It has a cylindrical shape, and a circular support hole is formed on the end surface on the detection side where the axial center line of the rod intersects the center, and a sphere to be brought into contact with the moving blade is supported by the support hole and connected to the housing. A support,
An arithmetic unit that is communicably connected to the displacement meter and measures an initial clearance that is a clearance during a turning operation that rotates the rotor at a lower speed than a normal operation in which the moving blade and the rotor rotate by a working fluid;
With
The detection side portion of the contact makes point contact with the sphere,
The sphere has a protrusion that is partially exposed in a convex shape from the support hole of the end surface on the detection side of the support,
When the casing and the support are installed by being inserted into a measurement opening formed so as to penetrate from the outer wall surface of the casing to the working fluid passage in which the moving blade is disposed, The entire bill enters the working fluid passage,
The displacement meter detects the displacement of the contact when the tip of the moving blade makes point contact with the protruding portion of the sphere during the turning operation, and the sphere is pushed into the contact. And
The said calculating part calculates | requires the said initial clearance corresponding to the said moving blade based on the said displacement received from the said displacement meter, The clearance measurement system characterized by the above-mentioned.   The calculation unit is configured to calculate the initial value based on the length from the inner wall surface to the top on the detection side of the sphere in the state where the casing and the support are installed in the measurement opening, and the displacement. The clearance measurement system according to claim 1, wherein the clearance is calculated.   The clearance measuring system according to claim 1, wherein the contactor has a detection-side end surface that is a plane perpendicular to the axial direction of the rod, and the plane is in point contact with the sphere. The support has a hole diameter adjusting mechanism installed on the inner surface side of the end surface where the support hole is formed,
The hole diameter adjusting mechanism has a ring-shaped adjustment hole formed in the center that allows the hole diameter to be adjusted, supports the sphere in contact with the peripheral edge of the adjustment hole, and performs the adjustment. The clearance measurement system according to any one of claims 1 to 3, wherein the allowance of the sphere is adjusted by adjusting a diameter of a hole. The casing has a cylindrical shape, and has a step portion formed by reducing the diameter of the detection side portion of the outer surface,
The step portion has a step portion fitting portion formed by being threaded on the inner surface,
The support body has a cylindrical shape having an outer diameter smaller than the inner diameter of the housing, supports the displacement meter inside, and is formed by being screwed into a predetermined range on the outer surface. The support body fitting portion and the stepped portion fitting portion are connected to the housing by fitting and rotating to move in the axial direction of the housing by rotating. The clearance measurement system according to any one of claims 1 to 4, which is possible. A measuring device support having a cylindrical shape and having a measuring device support fitting portion formed by being threaded on the inner surface and an insertion hole opened in the end surface on the detection side,
The support has a fitting portion formed by cutting a screw on the outer surface, and a stepped portion having a diameter reduced from a detection side end of the fitting portion of the outer surface,
The measuring device support is
It is possible to install a circular ring-shaped shim that contacts the inner surface side of the end surface on the detection side,
The stepped portion of the support body is inserted into the insertion hole, and the measurement device support body fitting portion and the fitting portion are fitted, thereby enabling connection to the support body,
When the shim is installed and connected to the support, the end surface opposite to the detection side of the shim comes into contact with the support,
When connected to the support without installing the shim, the inner surface of the end surface on the detection side abuts the support,
When the housing and the support are inserted and installed in the measurement opening, the end surface on the detection side abuts on a flange formed on the working fluid passage side in the measurement opening. The clearance measurement system as described in any one of Claims 1-4. A clearance measuring method for measuring a clearance between the tip of a moving blade fixed in parallel with the outer periphery of a rotor rotatably supported in the turbine and an inner wall surface of the casing of the turbine Because
Starting a turning operation for rotating the rotor at a lower speed than a normal operation in which the rotor rotates by receiving the pressure of fluid on the moving blades;
A displacement having a cylindrical housing, a main body arranged in the housing, a rod extending from the detection side portion of the main body in the axial direction of the housing, and a contact attached to the tip of the rod And a cylindrical support hole formed on the end surface on the detection side where the axial center line of the rod intersects with the center, and a sphere to be brought into contact with the moving blade is supported by the support hole. Inserting a clearance measuring device comprising a support connected to a measuring opening formed through the outer wall surface of the casing to a working fluid passage in which a moving blade is disposed; and
The tip of the moving blade is pointed to the sphere having a protrusion that is in point contact with the detection side portion of the contact and is partially exposed from the support hole of the end surface on the detection side of the support. Contacting and detecting displacement of the contact due to the sphere being pushed into the contact;
And a step of measuring an initial clearance, which is a clearance during the turning operation, based on the displacement of the contact.   In the step of detecting the displacement, when the displacement of the contact cannot be detected for all the moving blades corresponding to the measurement opening into which the clearance measuring device is inserted, The clearance measuring method according to claim 7, further comprising a step of preparing   In the step of detecting the displacement, when the displacement of the contact cannot be detected for all the moving blades corresponding to the measurement opening into which the clearance measuring device is inserted, the measurement opening is The clearance measuring method according to claim 7, further comprising a step of moving the support to the detection side with respect to the supported case. In the step of inserting and installing the clearance measuring device into the measurement opening, a cylindrical ring shape is formed, a circular ring-shaped shim is placed in contact with the inner surface side of the detection-side end surface, and the shim is detected In the state where the end surface opposite to the side is in contact with the support, the detection-side end surface of the measurement device support connected to the detection side of the support is connected to the working fluid passage side in the measurement opening. Abutting against the flange formed on
In the step of detecting the displacement, when the displacement of the contact cannot be detected for all the moving blades corresponding to the measurement opening into which the clearance measuring device is inserted, the clearance measuring device is Pull out from the measurement opening, remove the shim installed on the measurement device support, or install a shim thinner than the shim, and again connect the measurement device support to the support, The clearance measurement method according to claim 7, further comprising a step of inserting the clearance measurement device into the measurement opening and installing the clearance measurement device.

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