JP2011256751A - Guide vane state monitoring device of hydraulic power generation turbine, and turbine protection processing method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a guide vane state monitoring device of a hydraulic power generation turbine accurately monitoring the state of a guide vane of the hydraulic power generation turbine and early detecting abnormality to deal with it, and to provide a turbine protection processing method using the same.SOLUTION: Sensor fixtures (first sensor fixtures 20 and second sensor fixtures 22) are disposed each between predetermined positions of adjacent guide vane arms or members (guide vane pressing plates 11) following the guide vane arms. Detection sensors 23 each with an impedance varied in response with distance variation are provided on these sensor fixtures (the second sensor fixtures 22). A first series circuit formed by serially connecting between at least two selected detection sensors 23, and a second series circuit formed by serially connecting between at least two detection sensors 23 selected from the detection sensors other than those that configure the first series circuit, are parallelly connected. A bridge circuit having output terminals between middle points of the first and the second series circuit is configured so as to detect abnormality of the guide vane based on the output of this bridge circuit.

Description

  The present invention relates to a guide vane state monitoring device that monitors the state of a guide vane used in a hydroelectric turbine, and a turbine protection processing method using this device.

  A Francis turbine suitable for mid-head hydroelectric power generation is connected to the lower end of the water conduit and has a spiral casing that receives the water from the water conduit, and converts the energy of the water into rotational energy to transmit the rotational force to the main shaft. A runner, a plurality of movable guide vanes arranged in an annular shape so as to efficiently accelerate and supply flowing water supplied to the casing to the runner, and swing the guide vanes all at once to increase the opening of the water inlet It comprises a variable guide vane opening adjustment mechanism and a draft pipe that gradually reduces the flow velocity of water flowing in the axial direction through the runner and leads it to the water outlet.

  For example, as shown in FIGS. 9 to 11, the guide vane opening adjusting mechanism converts the movement of the servo motor 4 driven by a command from a speed governor (not shown) into a circumferential movement via a connecting rod 5. A guide ring 3 to be converted, a spectacle link 8 having one end connected to the guide ring 3 via an eccentric pin 7, and a guide vane arm 10 connected to the other end of the spectacle link 8 via a weak pin 9. The guide vane arm 10 is attached to the guide vane spindle 1a via a guide valve presser plate 11 fixed to the upper end surface of the guide vane spindle 1a integrated with the blade portion 1b of the guide vane 1 by a bolt 12. It is fixed. Accordingly, when the guide ring 3 is rotated in the circumferential direction as indicated by an arrow by the movement of the servo motor 4, the guide vane arm 10 has its axis centered via the eccentric pin 7, the glasses link 8, and the weak pin 9. The guide vane 1 swings all at once with the swing, and opens and closes the water mouth (see Patent Documents 1 and 2).

  Each of the guide vanes 1 is arranged inside the guide ring 3 in an annular shape at regular intervals (approximately 18 to 20) and is installed on the guide vane spindle 1a so as to have a uniform opening degree. It adjusts the amount of water by adjusting the opening by the guide vane opening adjustment mechanism, and plays a role of shutting off the flowing water to the runner when stopped.

JP-A-7-229468 JP 2009-167948 A

  However, since the guide vane opening adjustment mechanism is accompanied by the mechanical movement as described above, the rotation and sliding parts of the guide vane spindle and the like are worn out over many years of operation, and the opening characteristics of each guide vane are changed. There are inconveniences such as fluctuations, guide vane fully closed due to inclination of the guide vane spindle 1a, etc. (occurrence of guide vanes not being fully closed) and gaps between the guide vanes. .

  In order to deal with such inconveniences, conventionally, for each of the plurality of guide vanes 1, for each of the guide vanes 1, rattling, poorly closed state, gap variation between the guide vanes, and the like are manually measured or hydrated. We collect data by testing and regularly monitor the condition of the guide vanes. However, in such a human work, there is a disadvantage that it is impossible to detect an abnormality early or overlook it. is there.

  Further, if the foreign object is caught between the guide vanes during the operation of the water turbine, the stationary position of the guide vane 1 is shifted and the stress load is applied to the portion connected to the eyeglass link 8 of the guide vane arm 10. There is an inconvenience that the weak point pin 9 is broken due to an increase in size. Originally, the breakage at the weak pin 9 is desirable from the viewpoint of protecting the guide vane and the like, but if the weak pin 9 is broken, the turbine must be stopped for a long time to repair this portion. There is inconvenience that does not become.

  The present invention has been made in view of such circumstances, and is capable of accurately monitoring the state of a guide vane of a hydroelectric turbine, and capable of detecting and responding to an abnormality at an early stage. Provided is a water turbine guide vane state monitoring device and a water turbine protection processing method capable of protecting guide vanes while suppressing damage to a weak pin as much as possible when an abnormality is detected using such a device. This is the main issue.

  In order to achieve the above object, a guide vane state monitoring device for a hydroelectric turbine according to the present invention is a guide that reciprocates a drive device integrally with a guide vane via a guide ring, a link, and a weak pin. A guide vane opening adjustment mechanism that transmits to the vane arm is provided, and a sensor jig is installed between each predetermined position of the adjacent guide vane arm or a member that follows the guide vane arm, and the distance between the predetermined positions on the sensor jig A detection sensor that generates an impedance change in response to a change is provided, and a first series circuit in which at least two selected detection sensors are connected in series and a detection sensor other than the detection sensors constituting the first series circuit. A second series circuit formed by connecting at least two detection sensors selected from the above in series, and the first and second series circuits. Between the midpoint mutually constitute a bridge circuit and an output terminal is characterized by detecting an abnormality of the guide vanes on the basis of the output of the bridge circuit.

  Therefore, the output of the bridge circuit composed of the first series circuit and the second series circuit is monitored with respect to the detection sensor provided between the predetermined positions of the adjacent guide vane arms or the members following the guide vane arm. Thus, guides caused by changes in the distance between predetermined positions of adjacent guide vane arms or members following the guide vanes, gap variations, variations in opening characteristics and backlash, guide shaft inclination, etc. It becomes possible to detect a defect in the fully closed state of the vane.

Here, in the configuration in which the guide vane presser plate for fixing the guide vane arm is attached to the guide vane spindle of the guide vane, the sensor jig is the first sensor jig attached to the guide vane presser plate. A second sensor jig installed between the first sensor jigs attached to the adjacent guide vane presser plates, and the detection sensor is provided on the second sensor jig. Good.
With such a configuration, it is possible to respond by changing the guide vane retainer plate, so it becomes possible to retrofit the sensor jig to the guide vane of the existing water turbine, making a major equipment change Is no longer necessary.

Further, when there are two power transmission parts of the guide ring, the plurality of detection sensors constituting the first series circuit and the plurality of detection sensors constituting the second series circuit are the guide ring. The detection sensor is preferably arranged at a point-symmetrical position with respect to the center of the sensor.
By adopting such a configuration, guide vanes close to the power transmission part of the guide ring (guide vanes with fast power transmission) or guide vanes far from the power transmission part of the guide ring (guide with slow power transmission). Since the bridge circuit can be configured with the vanes), it is possible to monitor the states with similar operating environments, and it is possible to perform the state monitoring more accurately.

  In order to achieve the above object, the water turbine protection processing method according to the present invention eliminates the guide vane when an abnormality is detected based on the output from the bridge circuit of the above-described water turbine guide vane state monitoring device. Open once to near the load opening, and then determine whether or not the abnormal condition has been resolved based on the output from the bridge circuit.If it is determined that the abnormal condition has been resolved, the guide vane is fully closed. The turbine is stopped, and when it is determined that the abnormal state continues, the turbine is stopped with the guide vane opened to the vicinity of the no-load opening.

  In such a configuration, when an abnormal state is detected based on the output from the bridge circuit, the guide vane is once opened to the vicinity of the no-load opening degree. It can be expected that the abnormal state is resolved by flowing downstream. If it is determined that the abnormal state has been resolved based on the detection signal output from the Wheatstone bridge circuit after being opened once, the guide vane is fully closed and the water turbine is stopped, and the abnormal state still continues. If it is determined that the guide pin is open to the vicinity of the no-load opening degree, the water turbine is stopped to prevent breakage of the weak pin. In this case, equipment such as an inlet valve or a gate with the ability to block the inflow of water to the turbine is attached.

  The above water turbine protection process is performed not only when an abnormality is detected based on the signal from the bridge circuit during water turbine operation, but also when a manual water turbine forced stop command is issued. Therefore, even when a foreign object is caught between guide vanes at the time of a forced stop command, it can be expected to remove this, and even if it cannot be removed, it is possible to avoid the inconvenience that the guide vane and the weak pin are damaged. Become.

  As described above, according to the guide vane state monitoring device for a hydroelectric turbine according to the present invention, the distance between the adjacent guide vane arms or the sensor jigs installed between the predetermined positions of the members following the guide vane arms. A detection sensor that generates an impedance change in response to a change is provided, and a first series circuit in which at least two selected detection sensors are connected in series and a detection sensor other than the detection sensors constituting the first series circuit. A bridge circuit having an output terminal between the intermediate points of the series circuit and a second series circuit formed by connecting at least two detection sensors selected from the above in series. Because the guide vane abnormality is detected based on the output of the State can be accurately monitored for, also, it is possible to cope with the abnormality is detected at an early stage.

  Further, the sensor jig is installed between the first sensor jig attached to the guide vane holding plate for fixing the guide vane arm and the first sensor jig attached to the adjacent guide vane holding plate. By constructing the second sensor jig and providing the detection sensor in the second sensor jig, it is possible to retrofit the existing guide vane by replacing the guide vane holding plate. This eliminates the need for major equipment changes.

  Further, if the detection sensor constituting the first series circuit and the detection sensor constituting the second series circuit are selected so as to have a point-symmetric positional relationship with respect to the center of the guide ring, It is possible to perform state monitoring between similar detection sensors, and it is possible to perform state monitoring more accurately.

  Furthermore, when an abnormality is detected based on the output from the bridge circuit, the guide vane is temporarily opened to near the no-load opening, and then it is determined whether the abnormal state has been resolved based on the output from the bridge circuit. When it is determined that the abnormal state has been resolved, the guide vane is fully closed to stop the turbine, and when it is determined that the abnormal state continues, the guide vane is opened to near the no-load opening. If the water turbine is stopped in the state, it can be expected that the foreign state sandwiched between the guide vanes will flow downstream and the abnormal state will be resolved, and if it is determined that the abnormal state continues, By stopping the water turbine while the guide vane is opened to the vicinity of the no-load opening degree, it becomes possible to avoid breakage of the guide vane and the weak point pin.

  In addition, the above turbine protection process is performed not only during turbine operation but also when a turbine forced stop command is issued manually, so that it is sandwiched between guide vanes even during the forced stop command. It is possible to expect the removal of foreign matter, and even if it cannot be removed, it is possible to avoid the inconvenience of damaging the guide vane and weak point pin, and appropriately protect the guide vane and the guide vane opening adjustment mechanism that drives it It becomes possible to do.

FIG. 1 is a plan view showing a guide vane opening degree adjusting mechanism used in a guide vane state monitoring apparatus according to the present invention. FIG. 2 is an enlarged view of a part of the guide vane opening degree adjusting mechanism of FIG. 1, (a) is a diagram when the guide vane is in a closed state, and (b) is an open state of the guide vane. FIG. FIG. 3 is a cross-sectional view showing details of each member provided in the guide vane of the guide vane opening degree adjusting mechanism. FIG. 4 is an exploded perspective view showing a guide vane opening adjustment mechanism. FIG. 5 is an exploded perspective view showing a first sensor jig provided on the guide vane pressing plate and a second sensor jig connected to the first sensor jig. FIG. 6 is a diagram illustrating an example of a mutual monitoring circuit including a bridge circuit used in the guide vane state monitoring apparatus according to the present invention. FIG. 7 is a diagram illustrating an example in which the detection sensor is divided into four blocks and a bridge circuit is formed for each of the divided blocks. FIG. 8 is a flowchart showing a watermill protection processing method according to the present invention. FIG. 9 is a plan view showing a conventional guide vane opening adjusting mechanism. FIG. 10 is an enlarged view of a part of the guide vane opening degree adjusting mechanism of FIG. 9, (a) is a diagram when the guide vane is in a closed state, and (b) is an open state of the guide vane. FIG. FIG. 11A is a sectional view showing details of each member provided in the guide vane of the guide vane opening degree adjusting mechanism, and FIG. 11B is an exploded perspective view showing the guide vane opening degree adjusting mechanism. .

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a guide vane state monitoring device for a hydroelectric turbine according to the present invention will be described with reference to the accompanying drawings.

1 to 4 show a guide vane opening degree adjusting mechanism 2 for adjusting the opening degree of the guide vanes 1 arranged annularly around the main shaft 13 on the upstream side of the runner of the water turbine.
The guide vane opening degree adjusting mechanism 2 uses the link vane to drive the rotational force of the guide ring 3 arranged so as to surround the guide vane spindle 1a integrated with the blade portion 1b of each guide vane 1. In this way, the blade 1b of the guide vane 1 is opened and closed to adjust or block the flow rate in the water turbine. Specifically, the connecting rod 5 transmits the movement from the servo motor 4. Is connected to the guide ring 3 via the operation link pin 6, one end of the spectacle link 8 is connected to the eccentric pin 7 fixed to the guide ring 3, and the other end of the spectacle link 8 is connected to the weak pin. 9 is connected to a guide vane arm 10, and this guide vane arm 10 is fixed to the upper end surface of the guide vane spindle 1 a with a bolt 12. And it is secured to the guide vane spindle 1a through 1. In this example, 18 guide vanes 1 are provided at intervals of a central angle of 20 degrees.

  The servo motor 4 reciprocates the connecting rod 5 according to a command from a speed governor (not shown). The servo motor 4 is provided on both sides of the guide ring 3 and is guided through the connecting rod 5 at intervals of 180 degrees. 2 and two opposing locations where the connecting rod 5 of the guide ring 3 is connected are used as power transmission parts. In this example, the connecting rod 5 is connected to the guide ring 3 from the same direction, and the movement of one connecting rod 5 by driving the servo motor 4 is opposite to the movement of the other connecting rod 5. ing.

  Note that O is the center of the main shaft 13 and coincides with the center of the guide ring 3. Reference numeral 14 denotes a guide vane key for positioning and preventing rotation of the guide vane spindle 1a and the guide vane arm 10 of the guide vane 1, and 15 is screwed into a key groove into which the guide vane key 14 is fitted. A knock bolt for preventing the guide vane key 14 from coming off, and 16 is a fixing bolt for fixing the guide vane presser plate 11 to the guide vane arm 10.

  Therefore, when the connecting rod 5 reciprocates by driving the servo motor 4, the linear driving force is transmitted to the guide ring 3 through the operation link pin 6, and the guide ring 3 rotates about the main shaft 13. The rotational displacement of the guide ring 3 in the circumferential direction is transmitted to the guide vane spindle 1a via the link mechanism including the eccentric pin 7, the spectacle link 8, the weak point pin 9, and the guide vane arm 10. The blade portion 1b of the guide vane 1 is swung all at once to vary the opening of the water port so that the water flow flowing to the runner side of the water turbine can be controlled (adjusted or blocked).

  By the way, the guide vane retainer plate 11 attached to each guide vane 1 is attached with its extending portion 11a shifted in phase with respect to the extending direction of the guide vane arm 10, and the extending portion 11a is connected to the glasses link 8. The thickness is relatively thin so as not to interfere. Further, a jig mounting pin 19 for mounting the first sensor jig 20 on the tip of the extended portion 11a protrudes from the side opposite to the side facing the guide vane arm 10 (upward in the figure). Has been. In this example, the jig mounting pin 19 has a male screw formed on the outer peripheral surface thereof, and a nut 18 is screwed into the first sensor jig 20. Is pivotally attached.

  As shown in FIG. 5, the first sensor jig 20 includes a cylindrical portion 20a through which the jig mounting pin 19 is inserted through a slight clearance, and a pair projecting from both sides of the cylindrical portion 20a. The rod portions 20b adjacent to each other of the first sensor jig 20 attached to the adjacent jig attaching pins 19 are provided with gap adjusting bolts 21 screwed into the tips thereof. And is connected to the second sensor jig 22.

  The second sensor jig 22 is formed in a columnar shape having an axis substantially coincident with the axis of the rod part 20b so as to relay between the rod parts 20b facing each other of the first sensor jig 20, and is formed at both ends. A male screw that is screwed with the gap adjusting bolt 21 is formed, and a detection sensor that is sensitive to the force acting in the axial direction from both sides is provided at the intermediate portion. Even if this detection sensor is composed of a capacitor that detects the load acting in the axial direction of the second sensor jig as a capacitance change, it is composed of a resistance gauge or the like that detects the change in resistance value. Or a piezoelectric element whose impedance changes depending on the magnitude of the load acting in the axial direction. For example, a strain sensor disclosed in JP2009-36733, a position sensor disclosed in JP2007-304014, It is also possible to use a position sensor of 2008-70215 or the like. Then, by adjusting the gap between the first sensor jig 20 and the second sensor jig 22 by the gap adjustment bolt 21, the force acting on the detection sensor is initially set to a predetermined state, and the detection sensor The impedance is changed by changing the force (pulling force or compressive force) acting on both sides of 23.

  Therefore, a sensor jig (first and second sensor jigs 20, 22) is installed between the adjacent guide vane presser plates 11, and is adjacent to the second sensor jig 22. A detection sensor 23 is provided which generates an impedance change in response to a change in the distance between the jig mounting pins 19 of the guide vane retainer plate 11. This detection can also be performed by directly measuring the output value of the detection sensor. The behavior of the guide vane that rotates integrally with the guide vane presser plate to which the sensor is attached can be measured.

  A mutual monitoring circuit for detecting an abnormality of the guide vane 1 as shown in FIG. 6 is formed using the detection sensor 23 attached as described above. Specifically, a first series circuit is configured by connecting at least two selected detection sensors in series among 18 detection sensors 23 provided between adjacent guide vane presser plates 11, and The at least two detection sensors selected from those other than the detection sensors constituting the first series circuit are connected in series to form a second series circuit, and the first series circuit and the second series circuit Are connected in parallel to a constant current power supply 30 for supplying a constant current, and an unbalanced voltage is output at the time of unbalance using the intermediate points of the first series circuit and the second series circuit as output terminals. A Wheatstone bridge circuit is configured. The output terminal of the Wheatstone bridge circuit is provided with a main relay coil 31 to which an unbalanced voltage is applied. The main relay contact 32 operated by the main relay coil 31 is connected to the power supply Vcc together with the slave relay coil 33 in series. Further, the slave relay contact 34 operated by the slave relay coil 33 is connected to the power source Vcc, and an abnormality occurrence signal is generated when the slave relay contact 34 is closed. Therefore, when an unbalanced voltage is generated in the bridge circuit, an abnormality occurrence signal is output.

  Such a mutual monitoring circuit is formed independently for each bridge circuit configured by selecting different detection sensors. In the example shown in FIG. 1, 18 detection sensors are divided into four blocks. The presence / absence of abnormality detection is determined for each block.

  Specifically, as shown in FIG. 1, when the number of the guide vane is 1 to 18, the detection sensor 23 provided between the No. 1 guide vane and the No. 2 guide vane is provided. The detection sensor 23 provided between the No. 2 guide vane and the No. 3 guide vane is Se02, and the detection sensor 23 is numbered in the same manner, and the No. 18 guide vane and No. If the detection sensor 23 provided between the first guide vane is Se18, the Wheatstone bridge circuit of block 1 is Se01, Se09, Se10, Se18 (the first series circuit is Se01 and Se18, the second series circuit). Is composed of four detection sensors Se9 and Se10), and the Wheatstone bridge circuit of block 2 is Se02, Se08, Se11, Se17 (the first series circuit is Se02 and Se17, and the second series circuit is Se8 and Se11). 4) The Wheatstone bridge circuit of block 3 is composed of four detection sensors of Se03, Se07, Se12, Se16 (the first series circuit is Se03 and Se16, and the second series circuit is Se7 and Se12). The Wheatstone bridge circuit of block 4 is Se04, Se05, Se06, Se13, Se14, Se15 (the first series circuit is Se04, Se14, and Se15, and the second series circuit is Se05, Se06, and Se13). It consists of detection sensors. In the detection sensors of these blocks, the plurality of detection sensors constituting the first series circuit and the plurality of detection sensors constituting the second series circuit are point-symmetric with respect to the center O of the guide ring 3. Have been selected.

  That is, a block is formed for each detection sensor having a substantially equal distance from the power transmission part of the guide ring and similar operating environment. For example, in the block 1, the power transmission part (connecting rod 5) of the guide ring 3 is provided. Are connected to each other, and a bridge circuit is formed by the detection sensors between the guard vanes that are slow to transmit power and are slow in power transmission. In block 4, the distance from the power transmitting part of the guide ring is short and power transmission is fast. A bridge circuit is constituted by the detection sensors between the guard vanes.

Therefore, in the above configuration, a detection sensor having a similar operating environment is selected from the detection sensors 23 provided between the distal end portions of the guide vane presser plates 11 that are members following the adjacent guide vane arm 10. Since the bridge circuits are configured, monitoring the output of each bridge circuit (the presence or absence of occurrence of an abnormality occurrence signal from the mutual monitoring circuit), the time-dependent change in distance between adjacent guide vanes 1 Thus, it is possible to detect a failure in the fully closed state of the guide vane 1 due to variations in gaps, variations in opening characteristics, backlash, inclination of the guide vane spindle 1a, and the like.
When the occurrence of an abnormality occurrence signal is detected, it is possible to grasp detailed information such as the delay or catch of the guide vane 1 by measuring the output change of the bridge circuit individually with an oscilloscope or the like. .

  Further, the guide vane presser plate 11 attached to the guide vane spindle 1a of the guide vane 1 is improved, and the first sensor jig 20 is attached to the guide vane presser plate 11 and provided on the adjacent guide vane presser plate 11. Since the second sensor jig 22 is provided between the first sensor jigs 20, and the second sensor jig 22 is provided with a detection sensor 23 that generates an impedance change in response to a change in distance. It is possible to cope with this by changing the guide vane retainer plate 11 with respect to the guide vane 1 of the water turbine, so that the sensor jigs 20 and 22 and the detection sensor 23 can be retrofitted, and no major equipment change is required. Become.

  In the above configuration, the detection sensor configuring the first series circuit and the detection sensor configuring the second series circuit are selected so as to be point-symmetric with respect to the center of the guide ring 3. Therefore, it is possible to monitor the state of the guide vanes 1 with similar operating environments, and it is possible to more accurately monitor the state.

  In FIG. 8, the example of a watermill protection process using the guide vane state monitoring apparatus mentioned above is shown as a flowchart. The protection process shown here is performed when an abnormality occurrence signal is output during operation, and when a turbine stop command is manually issued, and the servo motor 4 that drives the guide vane 1 and the turbine are installed. A parallel circuit breaker that is disconnected from the power system, an inlet valve that is provided upstream of the water turbine of the water conduit and adjusts the amount of water flowing into the water conduit, and a start valve (not shown) that is activated when the guide vane is started and stopped. Control is performed according to the flowchart shown in FIG. 8 based on a control signal from the control unit, and is executed by executing a predetermined control program.

  When the water turbine is in operation, the control unit monitors whether or not an abnormality occurrence signal is output from the mutual monitoring circuit shown in FIG. 6 formed for each of the bridge circuits shown in FIG. 7 (step S1). If it is determined that the abnormality occurrence signal has been output, a turbine stop command is output (step S2), and the turbine stop process after step S4 is executed. Even when a turbine stop command is intentionally output in order to stop the turbine manually (step S3), the following turbine stop processing is performed.

  When receiving the water turbine stop command, the control unit drives the servo motor 4 to set the guide vane (GV) to an opening smaller than the no-load opening (step S4). Thereafter, in order to disconnect the water turbine from the power system, the parallel breaker is turned off (step S5), and a closing command for closing the guide vane 1 is output (step S6).

  Thereafter, it is determined whether or not an abnormality occurrence signal is output from each mutual monitoring circuit (step S7), and when it is determined that the abnormality occurrence signal is not output, in order to perform normal stop control that is performed normally. The guide vane 1 is fully closed (step S8), and then the start valve is closed and the water turbine is stopped (steps S9 and S10).

  On the other hand, when it is determined that an abnormality occurrence signal is output (when an abnormality occurrence signal is output during turbine operation, or after an artificial water turbine stop command, an abnormality occurrence signal is output from each mutual monitoring circuit. If it is output), the inlet valve is fully closed to shut off the flow of water to the water conduit (step S11), and then an opening command for opening the guide vane 1 is output (step S12). Is set to a no-load opening (step S13).

  Then, it is determined whether or not the output of the abnormality occurrence signal from the mutual monitoring circuit has been eliminated by such an opening operation of the guide vane (step S14), and if it is determined that it has been eliminated, the guide vane is closed. A closing command is output (step S15), the guide vane 1 is fully closed (step S16), and then the start valve is closed to stop the water turbine (steps S9 and S10).

  If it is determined in step S14 that the abnormality occurrence signal is still output from the mutual monitoring circuit (the abnormality occurrence signal output has not been eliminated), the guide vane remains set to the no-load opening. Then, the water wheel is stopped (step S10).

  Therefore, according to the stop operation processing as described above, when an abnormality occurrence signal is output from the mutual monitoring circuit (when an abnormality occurrence signal is output based on the detection signal output from the bridge circuit). In addition, whether or not the guide vane 1 is once opened to near the no-load opening degree, and then the abnormality occurrence signal output from the mutual monitoring circuit (abnormal state based on the detection signal output from the Wheatstone bridge circuit) has been resolved. When it is determined that the abnormal state has been resolved, the guide vane 1 is fully closed to stop the water turbine, and when it is determined that the abnormal state continues, the guide vane 1 is opened with no load. Since the turbine is stopped in a state where it is open to the vicinity of the degree, when an abnormal state is detected, by opening the guide vane to near the no-load opening degree, for example, The foreign matter caught between Idoben can be expected to eliminate the cause of the abnormal condition by flowing downstream. If it is determined that the abnormal state continues without being resolved, the water turbine stops with the guide vane 1 opened to near the no-load opening, so that the guide vane 1 and the weak pin 9 are broken. Can be prevented.

  Further, in the above configuration, the same stop operation processing is performed not only during the water turbine operation but also when a manual water turbine forced stop command is issued. Even if it is caught, it can be expected to remove this, and even if it cannot be removed, it is possible to avoid the inconvenience that the guide vane 1 and the weak pin 9 are damaged.

  In the above-described configuration, the example in which the first sensor jig 20 is attached to the guide vane presser plate 11 is shown. However, the guide vane arm 10 is improved and the first sensor jig is directly attached to the guide vane arm 10. The tool 20 may be attached. Further, the combination of the detection sensors 23 configuring each bridge circuit is not limited to the above case, and the mutual monitoring circuit may be configured by arbitrarily combining them.

DESCRIPTION OF SYMBOLS 1 Guide vane 1a Guide vane spindle 2 Guide vane opening adjustment mechanism 3 Guide ring 8 Glasses link 9 Weak point pin 10 Guide vane arm 11 Guide vane presser plate 20 1st sensor jig 22 2nd sensor jig 23 Detection sensor

Claims (5)

Guide vane state monitoring device for a hydroelectric power turbine equipped with a guide vane opening adjustment mechanism for transmitting a reciprocating motion of a drive device to a guide vane arm that rotates integrally with the guide vane via a guide ring, a link, and a weak point pin In
Sensor jigs are installed between the predetermined positions of the adjacent guide vane arms or the members following the guide vane arms, and a detection sensor is provided on the sensor jig to generate an impedance change in response to a change in the distance between the predetermined positions. ,
A first series circuit in which at least two selected detection sensors are connected in series, and at least two detection sensors selected from those other than the detection sensors constituting the first series circuit are connected in series. A bridge circuit having an output terminal between the intermediate points of the first and second series circuits is configured with a second series circuit connected in parallel.
An apparatus for monitoring the state of a water turbine guide vane, wherein an abnormality of the guide vane is detected based on an output of the bridge circuit.   A guide vane holding plate for fixing the guide vane arm to a guide vane spindle is attached to the guide vane, and the sensor jig is adjacent to a first sensor jig attached to the guide vane pressing plate. A second sensor jig installed between the first sensor jigs attached to the guide vane presser plate, and the detection sensor is provided on the second sensor jig. The state monitoring device for a water turbine guide vane according to claim 1, wherein:   When there are two power transmission parts of the guide ring, the plurality of detection sensors constituting the first series circuit and the plurality of detection sensors constituting the second series circuit are the center of the guide ring. The state monitoring device for a water turbine guide vane according to claim 1, wherein the state monitoring device is disposed at a point-symmetrical position with respect to the water turbine guide vane. In the waterwheel protection processing method using the waterwheel guide vane state monitoring device according to any one of claims 1 to 3,
When an abnormality is detected based on the output from the bridge circuit, the guide vane is once opened to near the no-load opening,
Then, it is determined whether the abnormal state has been resolved based on the output from the bridge circuit,
When it is determined that the abnormal state has been resolved, the guide vane is fully closed to stop the water turbine, and when it is determined that the abnormal state continues, the guide vane is moved to near the no-load opening. A watermill protection processing method characterized by stopping a watermill in an open state. The water turbine protection processing method is performed when an abnormality is detected based on a signal from the bridge circuit during a water turbine operation or when a manual water turbine stop command is issued. Item 4. The abnormality detection protection processing method according to Item 4.

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