JP4884433B2 - PACKING GAP MEASURING DEVICE, GAP SENSOR AND GAP MEASURING METHOD - Google Patents

Description

  The present invention relates to a packing gap measuring device, a gap sensor, and a gap measuring method, such as a labyrinth packing used in, for example, a steam turbine in a power plant.

  Generally, a labyrinth packing is used as a shaft seal device for a steam turbine in a power plant. This is because a plurality of thin annular teeth are arranged in the axial direction between the rotor, which is a rotating body, and stationary parts on the outer periphery of the rotor, and the pressure loss caused by bending the leakage flow path is utilized. The amount of leakage is reduced. The smaller the gap between the tip of the packing and the rotor, the smaller the amount of leakage. However, it is necessary to maintain a gap that does not cause contact with a rotating body that changes temperature during use, such as a steam turbine. is there. In a general steam turbine, this gap is assembled and managed in a range of about 0.5 mm to 2 mm.

  As a method of measuring the gap between the tooth tip of the packing and the rotor (hereinafter referred to as the gap between the tooth tips of the packing), a lead wire is put at the measurement location, and then the rotor and packing are temporarily assembled. In general, a method of measuring the gap between the tips of the packing and the diameter of the lead wire and the diameter of the lead wire is generally known.

  In addition, in view of the measurement error that is a problem with this measurement method and the fact that it takes a lot of man-hours, the gap between the tip of the projection and the projection facing surface in front of the tip of the projection can be easily and accurately determined. A gap measuring system capable of measuring has been proposed. In this gap measurement system, a deflection sensor mounting member, a deflection sensor, and a calculation means are provided, and the deflection sensor is inserted into a gap between the tip of the projection and the object facing the projection in front of the tip of the projection. The size of the gap can be measured without any change (see Patent Document 1).

JP 2004-93210 A

  Conventionally, the measurement operation of the gap between the tips of the packing disposed on the lower side of the turbine is performed by first lifting the turbine rotor, installing a lead wire at the measurement target location of the lower packing, and then hanging the turbine rotor. And then temporarily assembling with the packing, and then lifting the turbine rotor again, taking out the lead wire, measuring the depth of the depression on the lead wire, and calculating the gap between the tooth tips of the packing. It takes time.

  On the other hand, if the gap measurement system described above is used, the steps of installing lead wires, measuring the depth of depressions on the lead wires, and calculating the tooth gap of the packing from the measured values are eliminated, and the deflection sensor mounting member It is possible to easily and accurately measure the gap between the tooth tips of the packing at the place where is attached and arranged. However, it is not clear whether a lifting operation and a lifting operation of the turbine rotor are required when the deflection sensor mounting member is mounted on, for example, the teeth of the packing.

  In the work of measuring the tooth gap of the packing arranged under the turbine, it is necessary to lift and lift the turbine rotor at least twice, and much work and time are spent for this work. Yes. For this reason, there is a need for a gap measuring method and a gap measuring device that can measure the tooth tip gap of the packing without requiring lifting and lifting work of the turbine rotor.

  The present invention has been made on the basis of the above-described matters, and the object thereof is a gap that can accurately and easily measure the gap between the tooth tips of the packing without requiring the lifting and lifting work of the turbine rotor for measurement. The object is to provide a measuring device, a gap sensor, and a gap measuring method.

  (1) In order to achieve the above object, the present invention provides a packing gap measuring device for measuring a gap between a rotor and a tooth tip of a packing disposed on the outer periphery of the rotor. A gap sensor having an expansion / contraction deformation member inserted into a measurement portion between the rotor and a strain detector for measuring the expansion / contraction deformation amount of the member, and an insertion amount of the gap sensor to the measurement portion. An insertion amount detecting means for detecting, a sensor pressurizing means for sending expansion air to the gap sensor, and a pressurizing control to the sensor pressurizing means, and the distortion amount from the gap sensor and the insertion amount detecting means Measurement control means for calculating the gap data of the packing tooth tip, and calculating and monitoring the rate of change of the strain amount of the gap sensor by the pressurization control in the measurement control means, The rate of change is Shall be calculated clearance data packing addendum from the distortion amount at the time was reduced more than the value.

  (2) In the above (1), preferably, the gap sensor is inserted into a portion to be measured between the tooth tip of the packing and the rotor by reducing the expansion / contraction deformation member.

(3) In order to achieve the above object, the present invention provides an elastic material for a gap sensor used in a gap measuring device for a packing that measures a gap between a rotor and a tooth tip of a packing disposed on the outer periphery of the rotor. in the expansion and contraction of the formed collapsible hollow body, and a support portion having a guide portion of the groove-shaped sandwich the tooth tip of the packing, the inner bottom surface of the support part side of definitive to the expansion and contraction portion It is assumed that a strain gauge is attached.

(4) In the above (3), preferably, two strain gauges are attached to the inner bottom surface of the expansion / contraction portion on the support portion side , at both ends in a direction perpendicular to the groove direction of the guide portion. It is assumed that

  (5) In order to achieve the above object, the present invention provides a packing gap measuring device for measuring a gap between a rotor and a tooth tip of a packing disposed on the outer periphery of the rotor. A gap sensor having a cylindrical flexible deformation member to be inserted into a measured portion between the rotor and a distortion detector for measuring the amount of deflection of the member, and an insertion amount of the gap sensor to the measured portion An insertion amount detecting means for detecting a gap, and a measurement control means for inputting a distortion amount from the gap sensor and an insertion amount from the insertion amount detecting means, and calculating gap data of a packing tooth tip, and the measurement control means In this case, the gap data of the packing tooth tip is calculated from the difference from the distortion detection signal after insertion into the measurement target section with reference to the distortion detection signal before insertion into the measurement target section.

( 6 ) In order to achieve the above object, the present invention relates to a packing gap measuring method for measuring a gap between a rotor and a tooth tip of a packing disposed on the outer periphery of the rotor. A step of inserting a gap sensor into a measured portion between the rotor, a step of detecting the amount of insertion of the gap sensor to the measured portion, placing the gap sensor at a measurement position, and an operation of a trigger switch, A step of pressurizing the sensor pressurizing means to send expansion air to the gap sensor; a step of calculating and monitoring a rate of change of the strain amount of the gap sensor by the pressurization control by the measurement control means; A step of determining a strain amount when the rate of change of the strain amount decreases to a predetermined value or more and a step of calculating gap data of the packing tooth tip from the strain amount are executed. And the.

  According to the present invention, since the expandable / contractable gap sensor can be reduced and inserted into the gap portion, it is not necessary to lift and lift the turbine rotor for measurement. Can be measured accurately and easily. As a result, it is possible to improve the reliability of the measurement value of the packing tooth tip gap, and it is possible to shorten the measurement work time of the packing tooth tip gap and the packing gap adjustment work time, thereby streamlining these operations. be able to.

Hereinafter, embodiments of a packing gap measuring device, a gap sensor, and a gap measuring method according to the present invention will be described with reference to the drawings.
1 to 4 show a first embodiment of a packing gap measuring device according to the present invention. FIG. 1 shows a steam turbine equipped with the first embodiment of a packing gap measuring device according to the present invention. FIG. 2 is an enlarged vertical sectional view showing a part A of the packing gap measuring device of the present invention shown in FIG. 1, and FIG. 3 constitutes the packing gap measuring device of the present invention shown in FIG. FIG. 4 is a functional block diagram of a measurement control unit constituting the packing gap measuring device of the present invention shown in FIG. 1.

  1 and 2, the lower half side of the turbine rotor 2 is held by the packing ring holder 5 fixed to the stationary portion of the steam turbine and the packing ring holder 5, and the packing teeth 3 are arranged in the circumferential direction of the turbine rotor 2. And a packing ring 4 implanted along. In addition, the packing ring 4 and the packing teeth 3 can be divided into three parts, right and left and lower, as viewed in the axial direction of the turbine rotor 2. As shown in FIGS. 1 and 2, the packing ring 4 is provided in the packing ring holder 5 so as to be movable in the radial direction of the turbine rotor 2 by a leaf spring 6. Moreover, the turbine rotor 2 has the groove part 2b of the uneven | corrugated cross section which the protrusion part protruded from the bottom face 2a so that it may show in the circumferential direction. FIG. 1 shows a half state in which the packing holder 5 and the like arranged on the upper half side of the turbine rotor 2 are removed.

  A packing gap measuring device 1 according to the present embodiment is inserted between a packing tooth 3 which is a measured part and a bottom surface 2a of a groove 2b of the turbine rotor 2, and a gap sensor 7 which measures the gap of the packing tooth tip. And an insertion amount detector 8 that detects the amount of insertion of the gap sensor 7 to the measured part, a pressurizer 9 that supplies inflation air to the gap sensor 7, and pressurization control to the pressurizer 9. And a measurement control unit 10 for inputting a distortion signal from the gap sensor 7 and an insertion amount signal from the insertion amount detector 8 and calculating the gap data of the packing tooth tip. In FIGS. 1 and 2, the gap sensor 7 is disposed on the packing teeth 3 facing the bottom surface 2 a directly below the turbine rotor 2. On the other hand, the insertion amount detector 8, the pressurizer 9, and the measurement control unit 10 are arranged on, for example, the turbine floor.

  The insertion amount detector 8 can be constituted by, for example, a wire encoder that measures the drawing length of the wire B4. One end of the wire B4 is connected to the wire connection portion C4 on the side surface portion of the gap sensor 7, and the other end of the wire B4 is connected to the winding portion of the insertion amount detector 8. Further, the detected drawing length of the wire B 4 is converted into an insertion amount signal of the gap sensor 7 in the insertion amount detector 8. An insertion amount signal of the gap sensor 7 is transmitted to the measurement control unit 10 via the signal cable B2.

  The pressurizer 9 can be constituted by, for example, an electric air pump. One end of the pressure supply pipe B5 is connected to a supply pipe connection part C5 on the side surface of the gap sensor 7, and the other end of the pressure supply pipe B5 is connected to the air discharge part of the pressurizer 9. Further, a pressurizer control signal is transmitted from the measurement control unit 10 to the pressurizer 9 via the signal cable B1. The start, stop, and depressurization of pressurization to the gap sensor 7 in the pressurizer 9 are controlled according to the pressurizer control signal. The pressure reduction of the gap sensor 7 is controlled by an opening operation of an exhaust valve (not shown) communicated with the air discharge part of the pressurizer 9.

  In FIG. 3, the gap sensor 7 is an expansion / contraction deformation member formed substantially of an elastic material, and an expansion / contraction portion 7 a that is a hollow body that can be expanded / contracted is formed on the upper portion, and the tip portion of the packing tooth 3 is sandwiched between them. A support portion 7b having a groove-shaped packing tooth tip guide portion 7d is formed in the lower portion. The packing tooth tip guide portion 7 d is formed at the center of the side surface of the gap sensor 7. Thus, the tip of the packing tooth 3 can be easily arranged at the center of the gap sensor 7. The expansion / contraction part 7a has an oblong shape in a side view and a substantially rectangular shape in a plan view. A strain gauge 7c is attached to the inner bottom surface of the expansion / contraction part 7a with a suitable adhesive in a direction orthogonal to the groove direction of the packing tooth tip guide part 7d. In addition to the above-described wire connection portion C4 and supply pipe connection portion C5, a strain signal cable connection portion C6 is provided on the side surface portion of the expansion / contraction portion 7a, and is internally connected to the lead wire of the strain gauge 7c. Yes. The strain detection signal detected by the strain gauge 7c is transmitted from the signal strain cable connection unit C6 to the measurement control unit 10 via the strain signal cable B6. The left drawing of FIG. 3 shows the state of the gap sensor 7 before pressurization of air from the pressurizer 9, and the right drawing of FIG. 3 shows the state of the gap sensor 7 after pressurization. After pressurization, the expansion / contraction part 7a expands, and thereby the inner bottom surface of the expansion / contraction part 7a is distorted. This amount of strain can be measured with a strain gauge 7c attached to the inner bottom surface of the expansion / contraction part 7a. As the material of the outer shell of the gap sensor 7, for example, natural rubber, isoprene rubber, butyl rubber and the like are preferable in terms of resilience, high extensibility, and wear resistance.

  Returning to FIG. 2, the gap sensor 7 is set at a predetermined position of the groove portion 2 b of the turbine rotor 2 in a state where the packing tooth tip guide portion 7 d is fitted into the tip of the packing tooth 3. FIG. 2 shows a state where the gap sensor 7 is pressurized by the pressurizer 9 and the upper part of the outer shell of the gap sensor 7 is in contact with the bottom 2 a of the turbine rotor 2.

  In FIG. 4, the measurement control unit 10 includes a voltage value conversion processing unit 15 that converts a distortion detection signal input from the gap sensor 7 into a voltage value, a digital conversion processing unit 16 that converts the voltage value into a digital value, Voltage value storage processing unit 11 that stores this voltage value, voltage value display 12 that displays this voltage value, digital conversion processing unit 16 and time when the rate of change has changed from the voltage value storage processing unit 11 The rate-of-change determination processing unit 17 for detecting the voltage value at the gap, the gap value conversion processing unit 18 for converting the voltage value into a gap value, the gap data display 13 for displaying the gap value, and the gap sensor outer shell size. A measurement data calculation processing unit 19 that performs a calculation in consideration, a calculation processing result display 14 that displays the calculation processing result, a calculation processing result storage processing unit 22 that stores the calculation processing result, and a calculation result calculation An arithmetic processing result output processing unit 26 that performs output to the printer 29 and transfer to the external storage means 30; a measurement trigger processing unit 25 that activates each processing control program 21 according to the input signal of the trigger switch 28; A sensor pressurization processing unit 20 that controls the pressure device 9, a sensor insertion amount detection processing unit 23 that detects and processes a sensor insertion amount detection signal input from the insertion amount detector 8, and a sensor position calculation that calculates a sensor position. The processing unit 24 includes a sensor position display 27 that displays the calculated sensor position.

  Next, the operation of the above-described packing gap measuring method according to the first embodiment of the packing gap measuring apparatus of the present invention will be described with reference to FIGS. FIG. 5 is a flowchart for explaining a packing gap measuring method according to the first embodiment of the packing gap measuring apparatus of the present invention.

  First, as shown in FIG. 5, in step (S1), the measurement control unit 10 of the packing gap measuring device 1 displays a measurement screen by performing a predetermined operation after power-on, for example. At this time, as shown in FIG. 1, the insertion amount detector 8, the pressurizer 9, and the measurement control unit 10 are arranged, for example, on the turbine floor.

  In the next step (S2), the gap sensor 7 is inserted into the gap measuring part between the groove 2b of the turbine rotor 2 and the packing teeth 3. Specifically, the packing tooth 3 is placed on the packing tooth tip guide portion 7 d formed on the support portion 7 b of the gap sensor 7 along the shape of the tip of the packing tooth 3. Next, as shown in FIGS. 1 and 2, the gap sensor 7 is inserted below the turbine rotor 2 so as to slide on the packing teeth 3.

  In the next step (S3), the measurement control unit 10 performs a gap sensor insertion amount taking process. Specifically, in the insertion amount detector 8, the converted insertion amount signal is transmitted to the measurement control unit 10 and detected by the sensor insertion amount detection processing unit 23 of the measurement control unit 10.

  In the next step (S4), the measurement control unit 10 performs a gap sensor position calculation process. Specifically, the sensor position calculation processing unit 24 of the measurement control unit 10 performs calculation processing based on the detected gap sensor insertion amount. For example, in FIG. 1, when the diameter of the packing teeth 3 is D and the insertion amount of the gap sensor 7 is L, when the gap sensor is located directly below the turbine rotor 2 as shown in FIG. 1, L = π × D It is possible to calculate by / 4. The calculated position of the gap sensor 7 is displayed by the sensor position display 27 of the measurement control unit 10.

  In the next step (S5), it is determined whether or not the position of the gap sensor 7 has reached the measurement position. As described above, since the position of the gap sensor 7 is displayed by the sensor position display 27 of the measurement control unit 10, it is determined whether or not this display matches the intended position. If this step (S5) is NO, the process returns to step (S2) and the insertion of the gap sensor 7 is continued.

  When step (S5) is judged as YES, it moves to step (S6). In step (S6), pressurization control and gap measurement are executed. This step (S6) will be described in detail separately from step (S10) branch number 100 to step (S25) branch number 101.

  First, in step (S10), the trigger switch 28 is operated and measurement processing is started. Specifically, the measurement trigger processing unit 25 of the measurement control unit 10 transmits a trigger signal to each processing control program 21.

  In the next step (S11), the data in the storage unit is initialized. Specifically, data such as storage units H1, H2, and H3 in the voltage value storage processing unit 11 of the measurement control unit 10 is initialized. That is, the data value 0 is set in these storage units.

  In the next step (S12), internal pressurization of the gap sensor 7 is performed. Specifically, a pressurization start control signal is output from the sensor pressurization processing unit 20 of the measurement control unit 10 to the pressurizer 9, and the pressurization supply pipe B <b> 5 is connected from the pressurizer 9 to the expansion / contraction part 7 a of the gap sensor 7. Insufflation starts.

  In the next step (S13), a distortion signal is captured. That is, when the gap sensor 7 is pressurized, the gap sensor is deformed, and the strain detection signal of the strain gauge installed in the gap sensor 7 also changes. Specifically, the distortion detection signal from the gap sensor 7 is taken into the measurement control unit 10.

  In the next step (S14), voltage value conversion is performed. Specifically, the voltage value conversion processing unit 15 of the measurement control unit 10 converts the distortion detection signal taken from the gap sensor 7 into a voltage value. Here, the conversion of the strain detection signal into the voltage value is performed by a well-known means using a Wheatstone bridge circuit because the change in the output signal (resistance change) of the strain gauge is a minute value.

  In the next step (S15), digital conversion is performed. Specifically, the digital conversion processing unit 16 of the measurement control unit 10 converts the voltage value obtained by converting the distortion detection signal into a digital value.

  In the next step (S16), a digital value storing process is performed. Specifically, in the storage units H1, H2, and H3 in the voltage value storage processing unit 11 of the measurement control unit 10, the storage value of the storage unit H2 is stored in the storage unit H3, and the storage value of the storage unit H1 is stored in the storage unit H2. Evacuate each. Thereafter, the digital conversion value converted in step (S15) is stored in the storage unit H1. That is, in the first calculation after initialization, 0 is saved and stored in the storage units H2 and H3, respectively, and a certain value after distortion detection and conversion is stored in the storage unit H1.

  In the next step (S17), digital conversion value display is performed. Specifically, the digital conversion value is displayed on the voltage value display 12 of the measurement control unit 10.

  In the next step (S18), the interval value is converted. Specifically, the gap value conversion processing unit 18 of the measurement control unit 10 converts the digital conversion value into a gap value.

  In the next step (S19), a gap value ideogram is performed. Specifically, the gap value is displayed in the gap data display 13 of the measurement control unit 10.

  In the next step (S20), it is determined whether or not the data stored in the storage unit H2 in the voltage value storage processing unit 11 of the measurement control unit 10 is zero. If this step (S20) is determined as YES, the process returns to step (S12), and steps (S12) to (S19) are repeated. If this step (S20) is determined to be NO, the process proceeds to step (S21). As described above, in the first calculation after initialization, 0 is saved in the storage unit H2. Therefore, in the first calculation after initialization, the process returns to step (S12). In the second calculation step (S16), the storage value of the storage unit H1, which is the previous value, is saved in the storage unit H2. Therefore, in the second calculation step (S20), the step (S20) is performed. The determination is NO, and the process proceeds to step (S21).

  In the next step (S21), it is determined whether or not the data stored in the storage unit H3 in the voltage value storage processing unit 11 of the measurement control unit 10 is zero. If it is determined that step (S21) is YES, the process returns to step (S12), and steps (S12) to (S20) are repeated. If this step (S21) is determined to be NO, the process proceeds to step (S22). As described above, in the first and second computations after initialization, 0 is saved in the storage unit H3. Therefore, in the first and second operations after initialization, the process returns to step (S12). In the third calculation step (S16), the storage value of the storage unit H2, which is the previous value, is saved in the storage unit H3. Therefore, in the third calculation step (S21), the step (S21) is performed. The determination is NO, and the process proceeds to step (S22).

In the next step (S22), change rate determination processing is performed. Specifically, in the change rate determination processing unit 17 of the measurement control unit 10, the digital conversion value h1 at the time of calculation stored in the storage unit H1 and the previous digital conversion saved in the storage unit H2 An arithmetic processing of the following equation is performed from the value h2 and the digital conversion value h3 in the second order saved in the storage unit H3.
h1 / h2 <K × h2 / h3 (1)
Here, h1 / h2 represents the change rate of the digital conversion value at the time of calculation, and h2 / h3 represents the change rate of the digital conversion value one order before the time of calculation. K represents a coefficient for determining a change rate. That is, from the step (S12) as described above, since the pressurization of the gap sensor 7 is started, the gap sensor 7 starts to expand, and the strain signal also increases with the pressurization pressure. Go. However, as shown in FIG. 2, since the expansion of the outer shell portion of the gap sensor 7 is inhibited from the time when the outer shell portion of the gap sensor 7 comes into contact with the bottom surface 2a of the turbine rotor 2, the rate of change of the strain signal is reduced. Changes before and after the contact point. The rate of change after contact is smaller than the rate of change before contact. From this, if the predetermined change rate determination coefficient K is determined in advance by experiment or the like, the gap value of the packing tooth tip can be calculated from the change rate of the digital conversion value. FIG. 6 is an explanatory diagram showing a change rate characteristic based on the pressure applied to the gap sensor and the strain detection signal according to the first embodiment of the packing gap measuring device of the present invention. In FIG. 6, the horizontal axis represents the air pressure in the gap sensor 7, and the vertical axis represents the strain detection signal detected by the gap sensor 7. The rate of change of the strain detection signal at the pressure P1 or higher is smaller than the rate of change of the strain detection signal at the pressure P1 or lower. That is, the gap value of the packing tooth tip can be calculated from the digital conversion value of the gap sensor 7 at the time of the pressure P1. If this step (S22) is determined to be NO, the process returns to step (S12), and steps (S12) to (S21) are repeated. If this step (S22) is determined as YES, the process proceeds to step (S23).

  In the next step (S23), a gap value calculation process is performed. Specifically, the gap value conversion processing unit 18 of the measurement control unit 10 performs gap value conversion based on the digital conversion value saved in the storage unit H2, and the measurement data calculation processing unit 19 further performs gap sensor conversion. 7 Arithmetic processing is performed in consideration of the outer shell size.

  In the next step (S24), calculation processing result display / storage is performed. Specifically, the calculation processing result is displayed on the calculation processing result display 14 of the measurement control unit 10, and the calculation processing result is stored in the calculation processing result storage processing unit 22. Further, the arithmetic processing result output processing unit 26 outputs the arithmetic processing result to the printer 29 and transfers it to the external storage means 30.

  In the next step (S25), the gap sensor internal pressurization is stopped. Specifically, a pressurization stop control signal is output from the sensor pressurization processing unit 20 of the measurement control unit 10 to the pressurizer 9, and air supply from the pressurizer 9 to the expansion / contraction part 7 a of the gap sensor 7 is stopped. The Further, after the stop, for example, the clearance sensor 7 is decompressed by exhausting from an exhaust valve (not shown) of the pressurizer 9. Thus, the pressurization control and the gap measurement in step (S6) are completed, and the process proceeds to the next step (S7).

  In the next step (S7), the gap sensor is taken out. Specifically, it is the reverse process of step (S2) described above. That is, the gap sensor 7 inserted in the gap measuring part between the groove 2b of the turbine rotor 2 and the packing teeth 3 is pulled up above the turbine rotor 2 so as to slide on the packing teeth 3, and the packing teeth It is taken out from the previous gap. Since the outer shell of the gap sensor 7 is reduced by the decompression process in step (S25), it can be taken out smoothly.

  According to the first embodiment of the packing gap measuring device of the present invention described above, the expandable / shrinkable gap sensor 7 can be reduced and inserted into the gap portion. The tooth tip gap of the packing can be accurately and easily measured without the need for lifting and lifting work. As a result, it is possible to improve the reliability of the measurement value of the packing tooth tip gap, and it is possible to shorten the measurement work time of the packing tooth tip gap and the packing gap adjustment work time, thereby streamlining these operations. be able to.

  Further, by providing the insertion amount detector 8 for the gap sensor 7, the tooth tip gap of the packing at a desired position can be accurately and easily measured. Further, by providing the packing tooth tip guide portion 7 d on the support portion 7 b of the gap sensor 7, the tip of the packing tooth 3 can be easily disposed at the center of the gap sensor 7. As a result, the reproducibility of the arrangement of the gap sensor 7 is improved, and an accurate gap value can be measured.

  Further, for example, it is possible to reduce the number of times the turbine rotor is lifted and hung during the periodic inspection period of the turbine equipment, thereby reducing the work time and reducing the man-hour required for the periodic inspection of the turbine equipment. be able to.

  Next, a second embodiment of the packing gap measuring device of the present invention will be described with reference to FIG. FIG. 7 is a longitudinal sectional view for explaining the operation of the gap sensor used in the second embodiment of the packing gap measuring device of the present invention. In the following description, the same components as those in the first embodiment of the present invention described above are denoted by the same reference numerals, and description thereof is omitted.

  In the present embodiment, as shown in FIG. 7, two distortions are formed on the inner bottom surface of the expansion / contraction portion 7a of the gap sensor 7 at both ends in the direction perpendicular to the groove direction of the packing tooth tip guide portion 7d. A gauge 7c is attached. Each of the strain gauges 7c and 7c has a conductive wire, and transmits a strain detection signal to the measurement control unit 10 via the strain signal cable connection portion C6 and the strain signal cable B6. In the measurement control unit 10 shown in FIG. 4, two distortion detection signals are input, and two voltage values are obtained by the voltage value conversion processing unit 15. Subsequent calculation processing is executed based on these two voltage values. In the gap value conversion processing unit 18, calculation such as conversion to a gap value is performed after the average processing of the two digitally converted voltage values is performed. Processing is performed.

  According to the second embodiment of the packing gap measuring device of the present invention described above, the same effects as those of the first embodiment described above can be obtained, and the two strain gauges 7c are connected to the expansion / contraction part 7a. Even if the center of the outer shell of the gap sensor 7 is displaced from the packing tooth tip, the inner bottom surface of the gap sensor 7 is attached to both ends in the direction orthogonal to the groove direction of the packing tooth tip guide portion 7d. By using the average value of the two distortion amounts, the accuracy of gap measurement can be improved.

  Next, a third embodiment of the packing gap measuring device of the present invention will be described with reference to FIGS. FIG. 8 is a cross-sectional view of a steam turbine provided with the third embodiment of the packing gap measuring device of the present invention, and FIG. 9 is an enlarged view of part B of the packing gap measuring device of the present invention shown in FIG. FIG. 10 is a longitudinal sectional view for explaining the operation of the gap sensor constituting the packing gap measuring apparatus of the present invention shown in FIG. In the following description, the same components as those in the first embodiment of the present invention described above are denoted by the same reference numerals, and description thereof is omitted.

The packing gap measuring device according to the present embodiment differs from the packing gap measuring device according to the first embodiment described above in the following points, and the other points are common.
(1) As shown in FIG. 8, the packing gap measuring device 1 according to the present embodiment includes a gap sensor 7, an insertion amount detector 8, and a measurement controller 10, and includes a pressurizer 9. Not. Accordingly, the measurement control unit 10 does not include the sensor pressurization processing unit 20, the voltage value storage processing unit 11, and the change rate determination processing unit 17 in the first embodiment shown in FIG.

  (2) As shown in FIG. 10, the gap sensor 7 in the present embodiment is a flexible deformable member formed substantially of an elastic material, and a flexible portion 7h formed in a short cylindrical shape is provided at the top. A support portion 7b having a groove-shaped packing tooth tip guide portion 7d sandwiching the tip end portion of the packing teeth 3 is formed in the lower portion. The flexible portion 7h has a short cylindrical shape obtained by cutting a cylindrical member of a flexible member such as a plastic straw, for example. The flexible portion 7h is horizontally placed so that both ends that are openings of the short cylinder are in the horizontal direction. Have a different shape. The support portion 7b has a substantially long plate shape, and is integrally formed with the lowermost outer periphery of the horizontally placed short cylinder. The packing tooth tip guide portion 7 d is formed at the center portion of the support portion 7 b corresponding to the center portion of the side surface of the gap sensor 7. From this, the tip of the packing tooth 3 can be easily arranged at the center of the gap sensor 7. Two distortions at both ends (both ends opening of the short tube) in the direction perpendicular to the groove direction of the packing tooth tip guide portion 7d on the lower side of the inner peripheral surface of the short tube which is the inner bottom surface of the flexible portion 7h A gauge 7c is attached. The strain gauges 7c and 7c are attached in a direction parallel to the groove direction of the packing tooth tip guide portion 7d, and the flexible portion 7h is further pressed up and down so that the inner peripheral surface of the short cylinder which is the attachment surface is approximately. It is installed in a horizontal position. Each of the strain gauges 7c and 7c has a conductive wire, and transmits a strain detection signal to the measurement control unit 10 via the strain signal cable connection unit C6 and the strain signal cable B6.

  The drawing on the left side of FIG. 10 shows the state of the gap sensor 7 before insertion into the gap measurement unit between the groove 2b of the turbine rotor 2 and the packing teeth 3, and the drawing on the right side of FIG. The state of the sensor 7 is shown. Before the insertion into the gap measuring section, the cross section of the short cylinder of the flexible section 7h is substantially circular, and the strain gauges 7c, 7c attached to the lower side of the inner peripheral surface of the short cylinder are deformed (bent). The corresponding amount of distortion is detected. On the other hand, after insertion into the gap measuring section, the flexible section 7h is deformed (bent) according to the inserted gap, and the cross-sectional shape of the short cylinder is deformed into an elliptical shape. That is, the degree of curvature on the lower side of the inner peripheral surface of the short cylinder is reduced as compared with that before insertion. As a result, the strain amount detected by the strain gauges 7c, 7c also decreases. As described above, the strain gauges 7c and 7c disposed in the gap sensor 7 transmit the deformation amount (deflection amount) to the measurement control unit 10 as a strain detection signal. This makes it possible to measure the tooth tip gap of the packing. In this embodiment, unlike the first embodiment and the second embodiment described above, the gap measurement unit is referred to the distortion detection signal before being inserted into the gap measurement unit of the gap sensor 7. The tooth tip gap of the packing is obtained from the difference from the strain detection signal after insertion. As for the material of the gap sensor 7, for example, a plastic polymer resin such as polyester or polyimide is preferable in terms of elasticity and wear resistance. FIG. 9 shows a state in which the gap sensor 7 is set at a predetermined position and the upper part of the outer shell of the gap sensor 7 is in contact with the bottom 2 a of the turbine rotor 2.

  According to the third embodiment of the packing gap measuring device of the present invention described above, the flexible variable gap sensor 7 can be reduced and inserted into the gap portion. The tooth tip gap of the packing can be accurately and easily measured without requiring lifting and lifting work.

  Further, since the two strain gauges 7c are attached to the inner bottom surface of the flexible portion 7h and both ends in the direction perpendicular to the groove direction of the packing tooth tip guide portion 7d, the center of the outer shell of the gap sensor 7 is Even when the packing tooth tip is displaced, the accuracy of gap measurement can be improved by using the average value of the two distortion amounts.

1 is a transverse cross-sectional view of a steam turbine provided with a first embodiment of a packing gap measuring device of the present invention. It is a longitudinal cross-sectional view which expands and shows the A section of the packing clearance measuring apparatus of this invention shown in FIG. It is a longitudinal cross-sectional view explaining operation | movement of the gap | interval sensor which comprises the packing gap | interval measuring apparatus of this invention shown in FIG. It is a functional block diagram of the measurement control part which comprises the packing clearance measuring device of this invention shown in FIG. It is a flowchart figure explaining the packing gap | interval measuring method by 1st Embodiment of the gap | interval measuring apparatus of the packing of this invention. It is explanatory drawing which shows the change rate characteristic based on the pressurization pressure and distortion detection signal to the gap | interval sensor by 1st Embodiment of the gap | interval measuring apparatus of the packing of this invention. It is a longitudinal cross-sectional view explaining operation | movement of the gap | interval sensor used in 2nd Embodiment of the gap | interval measuring apparatus of the packing of this invention. It is a cross-sectional view of the steam turbine provided with 3rd Embodiment of the gap | interval measuring apparatus of the packing of this invention. It is a longitudinal cross-sectional view which expands and shows the B section of the packing clearance measuring apparatus of this invention shown in FIG. It is a longitudinal cross-sectional view explaining operation | movement of the gap | interval sensor which comprises the packing gap | interval measuring apparatus of this invention shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Packing clearance measuring device 2 Turbine rotor 2a Bottom face 2b Groove part 3 Packing tooth 4 Packing ring 5 Packing holder 6 Leaf spring 7 Gap sensor 7a Expansion / contraction part 7b Support part 7c Strain gauge 7d Packing tooth tip guide part 7h Flexible part 8 Insertion amount Detector 9 Pressurizer 10 Measurement control unit

Claims (6)

In the packing gap measuring device for measuring the gap between the rotor and the tooth tip of the packing disposed on the outer periphery of the rotor,
A gap sensor having an expansion / contraction deformation member inserted into a measurement target portion between a tooth tip of the packing and the rotor, and a strain detector for measuring the amount of expansion / contraction deformation of the member;
An insertion amount detection means for detecting the insertion amount of the gap sensor to the measured part;
Sensor pressurizing means for sending expansion air to the gap sensor;
Measurement control means for performing pressure control to the sensor pressure means, inputting the strain amount from the gap sensor and the insertion amount from the insertion amount detection means, and calculating gap data of the packing tooth tip,
In the measurement control means, the change rate of the strain amount of the gap sensor by the pressurization control is calculated and monitored, and the gap data of the packing tooth tip is obtained from the strain amount at the time when the change rate decreases to a predetermined value or more. A gap measuring device for packing, characterized in that it is calculated. In the packing gap measuring device according to claim 1,
The gap sensor is a packing gap measuring device, wherein the expansion / contraction deformation member is reduced and inserted into a measurement target portion between a tooth tip of the packing and the rotor. In the gap sensor used in the gap measurement device for packing, which measures the gap between the rotor and the tip of the packing disposed on the outer periphery of the rotor,
An expansion / contraction portion of a hollow body formed of an elastic material and capable of expansion / contraction;
A support portion provided with a groove-shaped guide portion sandwiching the tooth tip of the packing,
Gap sensor, characterized in that the strain gauge is mounted on the inner bottom surface of the support part side of definitive to the expansion and contraction portion. The gap sensor according to claim 3,
Two strain gauges are attached to both end portions of the expansion / contraction portion on the support portion side in the direction orthogonal to the groove direction of the guide portion. In the packing gap measuring device for measuring the gap between the rotor and the tooth tip of the packing disposed on the outer periphery of the rotor,
A gap sensor having a cylindrical flexible deformation member inserted into a measurement portion between a tooth tip of the packing and the rotor, and a strain detector for measuring the amount of deflection of the member;
An insertion amount detection means for detecting the insertion amount of the gap sensor to the measured part;
A measurement control means for inputting a strain amount from the gap sensor and an insertion amount from the insertion amount detection means, and calculating gap data of the packing tooth tip;
In the measurement control means, the gap data of the packing tooth tip is calculated from the difference from the distortion detection signal after insertion into the measurement target section with reference to the distortion detection signal before insertion into the measurement target section. Packing gap measuring device. In the packing gap measurement method for measuring the gap between the rotor and the tooth tip of the packing disposed on the outer periphery of the rotor,
Inserting a gap sensor into a measured portion between the tip of the packing and the rotor;
Detecting the amount of insertion of the gap sensor to the measured part and disposing the gap sensor at a measurement position;
A step of controlling the pressurization of the sensor pressurizing means to send expansion air to the gap sensor by operating the trigger switch;
Calculating and monitoring the rate of change of the strain amount of the gap sensor by the pressure control by the measurement control means; and
Determining the amount of distortion when the rate of change of the amount of distortion decreases to a predetermined value or more;
And a step of calculating gap data of the packing tooth tip from the distortion amount.

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