JP4359759B2 - Rider ring wear measuring device and wear life prediction method - Google Patents

Description

  The present invention relates to a rider ring wear measuring device and a wear life prediction method, which can directly measure the wear amount of a rider ring mounted on the outer periphery of a piston of a horizontal reciprocating compressor and predict the wear life of a rider ring with high accuracy. It is something that can be done.

  In general, in a horizontal reciprocating compressor or the like, as shown in FIG. 6, in addition to a piston ring 3 for sealing on the outer periphery of a piston 2 reciprocating in the cylinder 1 in the horizontal direction, a rider ring for load support 4 is mounted so that the load of the piston 2 is supported by the cylinder 1.

  This rider ring ensures clearance within the specified range between the piston and the cylinder liner, and at the same time, is made of a softer material than the cylinder liner so that the rider ring is worn due to reciprocation, and the rider ring is maintained during maintenance. It is made unnecessary to replace the cylinder liner.

  For this reason, it is necessary to know the amount of wear on the rider ring, and in the old days, the compressor was periodically stopped and opened every time it was operated for a specified time, and the clearance between the piston and cylinder liner was measured with a thickness gauge or the like. However, in recent years, various methods for measuring the wear amount of the rider ring while continuously operating have been proposed.

  For example, Patent Document 1 discloses a clearance sensor (for example, in FIG. 6) as a rider ring wear detection device that is provided on a cylinder inner circumferential surface in a reciprocating range of a piston and detects a radial space length of the cylinder. And a signal extraction means for extracting only a signal indicating the space length with the piston from the output signal of the clearance sensor, and a display means for displaying the extraction signal output from the signal extraction means. It is configured.

  Further, in Patent Document 2, as a rider ring wear measuring device, a mounting hole is formed in a cylinder liner so as to coincide with the top dead center of a piston head, and a displacement pickup (for example, symbol 5 in FIG. And a driver for amplifying the displacement signal detected thereby and displaying it on the monitor.

With any of these rider ring wear measuring devices, the wear amount of the rider ring can be measured even during operation.
Japanese Utility Model Publication No. 62-158304 Japanese Utility Model Publication No. 62-193507

  However, when the compressor uses evaporative gas (BOG) or other general flammable gas that evaporates from the storage tank installed in storage facilities such as liquefied petroleum gas (LPG) or liquefied natural gas (LNG). It must be used in hazardous environments and must meet the explosion-proof electrical machine type test, and no specific reference is made to such structure.

  The present invention has been made in view of the current state of the prior art, and has an explosion-proof structure and can accurately measure the wear amount of the rider ring and the wear life of the rider ring that can directly measure the wear amount of the rider ring during operation. It is intended to provide a rider ring wear prediction method that can be used.

In order to solve the above problems, a rider ring wear measuring device according to claim 1 of the present invention is provided with a sensor mounting hole penetrating a cylinder side wall facing the outer peripheral surface of a piston on which a rider ring is mounted. mounting a sensor for detecting the distance between the the mounting hole piston outer peripheral surface, provided with a receiver for receiving a detection signal from the sensor, it was interposed transmission box between the sensor and the receiver The sensor is composed of an eddy current sensor, the tip where the coil of the sensor is located is covered with a non-conductive ceramic sensor cover, and the difference in thermal expansion between the sensor body made of stainless steel is taken into consideration. An explosion-proof structure is formed by joining with silver solder, and the transmission box is used for termination and feedback of high-frequency current from the receiver. A current output terminal; a resonance circuit capacitor with the sensor; and a resonance characteristic change detection half-bridge. The sensor and the transmission box are connected by a sensor cable, and the resonance circuit capacitor in the transmission box The sensor cable is formed by forming a parallel resonant circuit with the sum of the capacities of the sensor cables, and the eddy current strength that changes due to the change in the distance from the sensor to the outer peripheral surface of the piston is changed in inductance of the coil of the sensor. And the receiver is configured to replace the inductance change with a change in resonance characteristics, while the receiver supplies a high-frequency current to generate an eddy current in the sensor, an amplifier, a detection circuit, a linearizer, and a sensor Bottom hold circuit that holds the minimum value of the AC component of the displacement output from And amplifying a detection signal as an inductance change detected as a change in the resonance characteristics, linearizing and outputting a signal following the change in the gap to the outer peripheral surface of the piston as a displacement output, The bottom hold circuit is configured to perform bottom hold of the AC component of the displacement output and output the minimum value of the gap as the conversion output to obtain the wear amount of the rider ring. .

According to this rider ring wear measuring device, a sensor mounting hole is provided in the cylinder side wall facing the outer peripheral surface of the piston on which the rider ring is mounted, and the distance from the piston outer peripheral surface is detected in the sensor mounting hole. And a receiver for receiving a detection signal from the sensor is provided, and a transmission box is interposed between the receiver and the sensor, and the sensor is constituted by an eddy current sensor. The tip of the sensor coil and the like is covered with a non-conductive ceramic sensor cover, and a stainless steel sensor body is joined with silver brazing in consideration of the difference in thermal expansion to constitute an explosion-proof structure. The transmission box is used to terminate the high-frequency current from the receiver, the return current output terminal for feedback, and the sensor. A circuit capacitor and a resonance characteristic change detection half bridge are configured, the sensor and the transmission box are connected by a sensor cable, and the sum of the capacitance of the resonance circuit capacitor in the transmission box and the sensor cable is A parallel resonant circuit is formed and configured, and the intensity of eddy current that changes due to a change in the distance from the sensor to the outer peripheral surface of the piston is detected as an inductance change of the coil of the sensor, and this inductance change is resonated. The receiver is configured to be replaced with a change in characteristics, while the receiver supplies a high-frequency current to generate an eddy current in the sensor, an amplifier, a detector circuit, a linearizer, and a minimum of the AC component of the displacement output from the sensor It comprises a bottom hold circuit that holds the value, and the resonance characteristics The detection signal as an inductance change detected as a change is amplified and linearized to output a signal following the change in the gap to the outer peripheral surface of the piston as a displacement output, and an AC component of the displacement output by the bottom hold circuit It is configured to output the minimum value of the gap as the conversion output by performing the bottom hold of the rider and to be the amount of wear of the rider ring , and connect to the receiver via the explosion-proof sensor and the transmission box Therefore, it is possible to measure the amount of wear of rider rings directly while securing an intrinsically safe explosion-proof structure. In addition, the sensor is composed of an eddy current sensor, and the sensor and the transmission box are connected by a sensor cable to form a parallel resonance circuit. The eddy current sensor supplies a high frequency current to the sensor. An eddy current is generated in the piston being measured, and the eddy current that changes due to the change in the distance to the piston is detected as a change in inductance by the sensor coil, and is paralleled by the sum of the capacitance in the transmission box and the sensor cable. A resonance circuit is formed, and an inductance change due to an eddy current can be changed to a change in resonance characteristics. The sensor tip is covered with a non-conductive sensor cover, and the sensor cover and sensor body are joined to form an explosion-proof structure. The sensor tip is covered with a non-conductive sensor cover and joined. By doing so, it protects against temperature and pressure, and has an explosion-proof structure.

Furthermore, the wear measuring device of the rider ring according to claim 2, wherein the present invention, in addition to the configuration of claim 1, wherein, while a low reactance with respect to the measuring frequency between the receiver and the transmission box power supply A safety retainer that forms a barrier with high reactance with respect to frequency is provided.

According to this rider ring wear measuring device, the safety retainer between the transmission box and the receiver has a low reactance with respect to a high frequency for measurement but a high reactance with respect to a power supply frequency to form a barrier . By providing this safety retainer, it is possible to form a barrier having a low reactance with respect to the high frequency for measurement and a high reactance with respect to the power supply frequency, and an intrinsically safe explosion-proof structure can be obtained. .

Furthermore, the wear measuring apparatus for rider rings according to claim 3 of the present invention is provided with a protection member for protecting the tip of the sensor cover of the sensor inside the cylinder side wall in addition to the configuration according to claim 1 or 2. In addition, a sensor washer for adjusting the position of the front end surface of the sensor is interposed at the base end portion of the sensor mounting hole.

  According to this rider ring wear measuring device, the protective member for protecting the tip of the sensor cover of the sensor is attached to the inside of the cylinder side wall, and the position of the tip of the sensor is positioned at the base end of the sensor attachment hole. The sensor washer to be adjusted is installed, and even if it is damaged by the protective member, the sensor cover is prevented from entering the cylinder, and the sensor tip is changed by changing the thickness of the sensor washer. The position of the surface can be adjusted.

According to a fourth aspect of the present invention, there is provided a method for predicting wear of a rider ring according to any one of the first to third aspects, wherein the wear amount of the rider ring is determined from a change in distance to the outer peripheral surface of the piston on which the rider ring is mounted. Detected by the described rider ring wear measuring device , this detection signal is collected at regular time intervals, and the operation time is accumulated, and the current operation time is the expected wear amount of the rider ring based on previous experience. When the time that is expected to exceed the wear amount detection error is exceeded, the slope of the wear prediction diagram of the wear amount with respect to the operation time is calculated using the collected information of the detection time and wear amount so far Then, a wear prediction diagram is drawn from the final measurement point based on this inclination, and the remaining life until reaching a predetermined wear limit is obtained.

According to the method for predicting the wear life of a rider ring, the wear amount of the rider ring according to any one of claims 1 to 3, wherein the wear amount of the rider ring is determined from a change in distance to an outer peripheral surface of a piston on which the rider ring is mounted. Detecting with a measuring device, collecting this detection signal at regular intervals, integrating the operation time, the operation time until now , the expected wear amount of the rider ring based on the experience so far is the detection of the wear amount When the elapsed time expected to exceed the error is exceeded, the slope of the wear prediction diagram of the wear amount with respect to the operation time is calculated using the collected information of the detection time and wear amount so far, and based on this slope Draw a wear prediction diagram from the final measurement point to obtain the remaining life until reaching the predetermined wear limit, and to the outer peripheral surface of the piston with the rider ring attached Distance amount of wear of the rider rings from the change in detected by the wear measuring device of the rider ring as claimed in any one of claims 1 to 3, the operating time until it exceeds a predetermined time, without life prediction, thereby wear In order to avoid the influence of the measurement accuracy of the quantity, after a predetermined time has passed, the slope of the wear prediction diagram of the wear amount relative to the operating time is calculated using the collected information of the detection time and wear amount so far, and this slope is calculated. By drawing a predicted wear diagram from the final measurement point based on the above, the remaining life until reaching a predetermined wear limit can be obtained with high accuracy. Further, the operation time after the lapse of the predetermined time is set to be after the lapse of time when the expected wear amount of the rider ring based on the experience so far exceeds the detection error of the wear amount. Until the operation time exceeding the detection error elapses, the remaining life is not predicted, and the life can be predicted with high accuracy.

Furthermore, in the wear prediction method for rider rings according to claim 5 of the present invention, in addition to the configuration according to claim 4 , the wear detection signal is collected once every 24 hours. It is characterized by this.

  According to the method for predicting the wear life of the rider ring, the wear detection signal is collected once every 24 hours, and it is necessary to set such a certain time as necessary. The remaining life of accuracy can be predicted.

Further, in the wear prediction method for rider rings according to claim 6 of the present invention, in addition to the configuration according to claim 4 or 5 , the predetermined time for starting the prediction of the wear amount is set to 1000 hours. It is a feature.

  According to this method for predicting the wear life of a rider ring, the predetermined time for starting the prediction of the wear amount is set to 1000 hours, and after 1000 hours, the wear amount that can be detected without any detection error. Based on the experience that it can be obtained, the remaining life is predicted with high accuracy.

According to a seventh aspect of the present invention, in addition to the structure according to any one of the fourth to sixth aspects, the calculation of the inclination of the predicted wear diagram is performed by the least square method. It is characterized by that.

  According to this method for predicting the wear life of rider rings, the slope of the predicted wear diagram is calculated by the least square method, and the slope of the predicted wear diagram can be calculated relatively easily, with the required accuracy. It will be possible to predict the remaining life of the product.

Furthermore, the wear prediction method of the rider ring according to claim 8 of the present invention is the operation used for predicting the wear amount after the replacement of the rider ring in addition to the configuration according to any one of claims 4 to 10. It is characterized in that the time integration can be changed after the replacement.

  According to the method for predicting the wear life of the rider ring, after the rider ring is replaced, the accumulated operating time used for the wear amount prediction can be changed after the replacement. In this case, the remaining life can be predicted with high accuracy even after the replacement by predicting the remaining life using the operation time accumulated from the time of replacement, which can be changed.

According to the rider ring wear measuring apparatus of the first aspect of the present invention, according to the rider ring wear measuring apparatus, the sensor mounting hole is passed through the cylinder side wall facing the outer peripheral surface of the piston on which the rider ring is mounted. The sensor mounting hole is provided with a sensor for detecting the distance from the outer peripheral surface of the piston, and a receiver for receiving a detection signal from the sensor is provided, and a transmission box is provided between the receiver and the sensor. The sensor is composed of an eddy current sensor, the tip where the coil of the sensor is located is covered with a non-conductive ceramic sensor cover, and the stainless steel sensor body is heated. In consideration of the expansion difference, it is joined with silver solder to form an explosion-proof structure, and the transmission box has a high-frequency current termination from the receiver. A feedback current output terminal for feedback, a capacitor for a resonance circuit with the sensor, and a half bridge for resonance characteristic change detection, the sensor and the transmission box are connected by a sensor cable, The sum of the capacitance of the resonance circuit capacitor and the sensor cable is formed to form a parallel resonance circuit, and the intensity of the eddy current that changes due to a change in the distance from the sensor to the outer peripheral surface of the piston is determined. The receiver detects the change in inductance of the coil and replaces the change in inductance with a change in resonance characteristics, while the receiver supplies a high-frequency current to generate an eddy current in the sensor, an amplifier, and a detector. Hall the minimum AC component of displacement output from circuits, linearizers and sensors A signal that follows a change in the gap to the outer peripheral surface of the piston as a displacement output by amplifying a detection signal as an inductance change detected as a change in the resonance characteristic and linearizing the detection signal. In addition, the bottom hold circuit performs the bottom hold of the alternating current component of the displacement output and outputs the minimum value of the gap as the conversion output to obtain the wear amount of the rider ring. By connecting to the receiver via the structure sensor and the transmission box, it is possible to directly measure the wear amount of the rider ring while securing the intrinsically safe explosion-proof structure. In addition, since the sensor is composed of an eddy current sensor, and the sensor and the transmission box are connected by a sensor cable to form a parallel resonance circuit, a high-frequency current supplied to the sensor by the eddy current sensor is used. An eddy current is generated in the piston being measured, and the eddy current that changes due to the change in the distance to the piston is detected as a change in inductance by the sensor coil, and is paralleled by the sum of the capacitance in the transmission box and the sensor cable. A resonance circuit can be formed to change an inductance change due to an eddy current to a change in resonance characteristics, and the wear amount can be measured with higher accuracy. In addition, since the tip of the sensor is covered with a non-conductive material sensor cover and the sensor cover and the sensor body are joined to form an explosion-proof structure, the sensor tip is covered with a non-conductive material sensor cover. By joining, the sensor itself can be protected from temperature and pressure, and the sensor itself can have an intrinsically safe explosion-proof structure.

Furthermore, according to the wear measuring device of the rider ring of claim 2 of the invention, a high reactance to the power source frequency becomes low reactance with respect to the measuring frequency between the receiver and the transmission box Safety Since a cage is provided, by providing this safety cage, it is possible to form a barrier that has a low reactance with respect to the high frequency for measurement and a high reactance with respect to the power supply frequency. Safe explosion-proof structure can be used.

Furthermore, according to the wear measuring apparatus for rider rings according to claim 3 of the present invention, the protective member for protecting the tip of the sensor cover of the sensor is attached to the inside of the cylinder side wall, and the base end of the sensor attachment hole Since the sensor washer for adjusting the position of the front end surface of the sensor is interposed in the part, even if it is damaged by the protective member, the sensor cover and the like can be prevented from entering the cylinder, By changing the thickness of the sensor washer, the position of the front end surface of the sensor can be easily adjusted.

According to the rider ring wear prediction method of claim 4 of the present invention, the rider ring wear amount is determined from the change in the distance to the outer peripheral surface of the piston on which the rider ring is mounted. detected by the wear measuring device of the rider rings described crab, as well as collecting the detection signal at every predetermined time, integrates the operation time, the operation time until now expected of the rider rings based on previous experience When the amount of wear exceeds the time expected to exceed the wear amount detection error, the slope of the wear prediction diagram of the wear amount with respect to the operation time using the collected information of the detection time and wear amount so far Based on this slope, a wear prediction diagram was drawn from the final measurement point, and the remaining life until the predetermined wear limit was reached was calculated. From the change in the distance to the outer circumferential surface of the piston is detected by the wear measuring device of the rider rings which describes the amount of wear of the rider rings to any of claims 1 to 3, until the operation time exceeds the predetermined time, the life prediction In this way, the influence of the measurement accuracy of the amount of wear is avoided, and after a predetermined time has elapsed, using the collected information of the detection time and the amount of wear so far, the slope of the wear prediction diagram of the amount of wear with respect to the operation time , And a wear prediction diagram is drawn from the final measurement point based on this slope, so that the remaining life until reaching a predetermined wear limit can be obtained with high accuracy. Further, since the operation time after the predetermined time has elapsed is set to be after the time when the expected wear amount of the rider ring based on the experience so far exceeds the detection error of the wear amount, the wear amount Until the operation time exceeding the detection error elapses, the remaining life is not predicted, the influence of the detection error can be avoided, and the remaining life by calculation can be predicted with high accuracy.

Further, according to the rider ring wear prediction method according to claim 5 of the present invention, the wear detection signal is sampled once every 24 hours. By setting, the remaining life can be predicted with the required accuracy.

Furthermore, according to the rider ring wear prediction method according to claim 6 of the present invention, the predetermined time for starting the prediction of the wear amount is set to 1000 hours. Based on the experience that a low wear amount can be obtained, the remaining life can be predicted with high accuracy thereafter.

According to the method for predicting wear of a rider ring according to claim 7 of the present invention, since the calculation of the slope of the predicted wear chart is performed by the least square method, the slope of the predicted wear chart is relatively easy. The remaining life can be predicted with a required accuracy.

Further, according to the rider ring wear prediction method according to claim 8 of the present invention, after replacement of the rider ring, the setting of the accumulated operation time used for prediction of the wear amount can be changed after the replacement. Therefore, even if the rider ring is replaced, it is possible to predict the remaining life with high accuracy even after replacement by predicting the remaining life using the operation time accumulated from the time of replacement that allows setting change.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 and 2 relate to an embodiment of a rider ring wear measuring apparatus according to the present invention. FIG. 1 is an overall schematic configuration diagram, and FIG. 2 is a sectional view of a sensor and its mounting state.

  As shown in FIG. 1, the rider ring wear measuring device 10 is a compressor installed in a hazardous environment such as an evaporative gas (BOG) compressor provided in a storage facility for liquefied natural gas, for example. Explosion-proof electromechanical equipment type certification for use in hazardous environments, allowing wear measurement of the load-supporting rider ring 4 attached to the outer periphery of the piston 2 that reciprocates horizontally. It conforms to.

  The rider ring wear measuring device 10 includes an explosion-proof sensor 11 and is composed of, for example, an eddy current sensor. As shown in an enlarged view in FIG. 2, a tip portion where a coil of the sensor body 11a is located. Is covered with a non-conductive sensor cover 11b, which is covered with, for example, a ceramic sensor cover 11b and joined to the sensor body 11a.

  In this sensor 11, the sensor body 11a is made of stainless steel, and is joined with silver brazing in consideration of the thermal expansion difference from the sensor cover 11b made of ceramics, thereby ensuring an explosion-proof structure.

  Further, in this sensor 11, a large-diameter flange-like seal portion 11c is provided at the intermediate portion, and a screw portion 11d is formed in front of the seal portion 11c so that it can be attached to the cylinder 1.

  In order to mount such a sensor 11, a sensor mounting hole 12 is formed on the compressor side at a position facing the outer peripheral surface of the cylinder 1 and the piston 2 of the cylinder liner 1 a. A step-shaped seal surface 12a having a small diameter toward the inside of the cylinder 1 is formed in the intermediate portion. When the seal portion 11c of the sensor 11 is applied to the seal surface 12a, the tip surface of the sensor 11 is attached to the cylinder. It is adapted to match the liner surface of the liner 1a.

  Then, by selecting and inserting a sensor washer 13 that also serves as a sealing gasket having a different thickness between the seal portion 11 c of the sensor 11 and the seal surface 12 a of the sensor mounting hole 12, The position can be adjusted.

  Further, the cylinder liner 1a portion of the sensor mounting hole 12 has a diameter larger than that of the tip of the sensor 11, and a protective member 14 that covers the outer periphery of the tip of the sensor 11 is disposed. Even if the sensor cover 11b is broken, The protection member 14 is made of Teflon (registered trademark) and bolts (for example, those of SCM440 are used, and it has been confirmed that eddy currents are not affected. ) And attached from the inside of the cylinder 1.

  The rider ring wear measuring apparatus 10 includes a receiver 15 that receives a detection signal from the sensor 11, and a transmission box 16 is provided between the sensor 11 and the receiver 15. Are connected by a sensor cable 17 with a flexible tube, and the transmission box 16 and the receiver 15 are connected by a transmission cable 18 with a corrugation so that an explosion-proof structure can be secured.

  The transmission box 16 includes a high-frequency current termination from the receiver 15, a feedback current output terminal for feedback, a capacitor for a resonance circuit with the sensor 11, and a resonance characteristic change detection half bridge.

  The sensor 11 connected to the transmission box 16 and the sensor cable 17 forms a parallel resonance circuit by the sum of the capacitance of the transmission box 16 and the sensor cable 17, and changes in inductance due to eddy currents have resonance characteristics. It is intended to replace change.

  Furthermore, a safety holder 19 is provided at the entrance of the receiver 15 and includes a high withstand voltage capacitor and a resistor. The reactance is low reactance for a high frequency for measurement and high reactance for a power supply frequency. A barrier is formed.

  In addition, the receiver 15 includes a transmitter, which supplies a high-frequency current to the sensor 11 to generate an eddy current on the outer peripheral surface of the piston 2 as a measurement object, and includes an amplifier, a detection circuit, and a linearizer. The intensity of the eddy current that changes due to the change in the distance from the sensor 11 to the outer peripheral surface of the piston 2 is detected as a change in the inductance of the coil of the sensor 11, this detection signal is amplified, linearized, and output as a displacement output of the piston 2. In addition to outputting a signal that follows the change in the gap to the outer peripheral surface, it is equipped with a bottom hold circuit that performs bottom hold of the AC component of the displacement output and outputs the minimum value of the gap as the conversion output. The wear amount of the rider ring 4 can be known from the minimum value of the gap.

  Then, the detection result of the wear amount of the rider ring 4 is output to the rider ring wear monitoring panel 20, and the wear amount is displayed, recorded, and monitored.

  According to the rider ring wear measuring apparatus 10 as described above, the sensor mounting hole 12 is provided through the cylinder 1 and the cylinder liner 1a facing the outer peripheral surface of the piston 2 to which the rider ring 4 is mounted. A sensor 11 having an explosion-proof structure for detecting the distance from the outer peripheral surface of the piston 2 is attached to 12, a receiver 15 for receiving a detection signal from the sensor 11 is provided, and transmission is performed between the receiver 15 and the sensor 11. Since the box 16 is interposed, the wear amount of the rider ring 4 is directly measured while securing the intrinsically safe explosion-proof structure by connecting to the receiver 15 through the explosion-proof sensor 11 and the transmission box 16. be able to.

    In addition, the sensor 11 is composed of an eddy current sensor, and the sensor 11 and the transmission box 16 are connected by a sensor cable 17 to form a parallel resonance circuit. Therefore, the sensor 11 is supplied to the sensor by the eddy current sensor 11. An eddy current is generated in the piston 2 that is the object to be measured with a high-frequency current, and an eddy current that changes due to a change in the distance to the piston 2 is detected as a change in inductance by the coil of the sensor 11. A parallel resonance circuit is formed by the sum of the capacities of the cables 17, and an inductance change due to an eddy current can be changed to a change in resonance characteristics, so that the wear amount can be measured with higher accuracy.

  Further, since the safety holder 19 is provided between the transmission box 16 and the receiver 15, the safety holder 19 provides a low reactance with respect to the measurement high frequency and a high reactance with respect to the power supply frequency. The barrier can be formed, and the safety can be further enhanced to provide an intrinsically safe explosion-proof structure.

  In addition, the tip of the sensor 11 is covered with a sensor cover 11b made of a non-conductive material, and the sensor cover 11b and the sensor main body 11a are joined together with silver solder to form an explosion-proof structure. The sensor cover 11b made of a conductive material can protect against temperature and pressure, and the sensor itself can have an intrinsically safe explosion-proof structure.

  Further, a protective member 14 that protects the distal end portion of the sensor cover 11 b of the sensor 11 is attached to the inside of the side wall of the cylinder 1, and the position of the distal end surface of the sensor 11 is adjusted to the seal surface 12 a of the proximal end portion of the sensor attachment hole 12. Since the sensor washer 13 is interposed, the sensor cover 11b and the like can be prevented from entering the cylinder 1 even if it is damaged by the protective member 14, and the thickness of the sensor washer 13 can be prevented. By changing the height, the position of the tip surface of the sensor 11 can be easily adjusted.

  Next, a rider ring wear prediction method performed using the measurement result of the rider ring wear measuring apparatus 10 will be described with reference to FIGS.

As shown in FIG. 1, the wear prediction of the rider ring is performed by a computer, monitor, print display device, etc. of a life monitoring system installed in the central control room, and depends on the operating conditions and the state of the sliding surface of the cylinder liner. Rider ring wear that gradually changes is predicted with high accuracy based on past and present wear rate data.
In this rider ring wear prediction, wear data and its time collection and operation time are accumulated by a computer. For example, data is collected once every 24 hours in actual operation time, and the data is collected for at least two years. I try to record. This is because, in normal operation, the rider's ring is exchanged for two years, and therefore data for at least two years is sufficient for predicting the amount of wear.

  Further, in the wear prediction of the rider ring, the wear prediction is not performed until the operation time reaches 1000 hours after the rider ring is in a new state.

  This is because the measurement error by the wear amount sensor is 0.2 mm, but from the experience so far, the wear amount of the rider ring after 1000 hours of operation is expected to be 0.2 to 0.3 mm. This is because the accuracy cannot be predicted and the life of the rider ring is not reached during this time, and there is no need to predict in particular.

  Thus, since the wear prediction is not performed when the operation time is 1000 hours or less, when the rider ring is replaced, it is necessary to reset the operation integration time used for wear prediction. At the time of replacement, the time is returned so that it can be reset.

  As shown in the flow chart of FIG. 3, the specific rider ring wear prediction performed under such conditions takes in the accumulated operation time X1, and the accumulated operation time of the rider ring currently installed is 1000 hours. Judge whether it is above.

  If the accumulated operation time up to the present is 1000 hours or less, the wear of the rider ring is not predicted, and the process ends as shown in FIG.

  On the other hand, when the accumulated operation time up to now exceeds 1000 hours, the wear prediction of the rider ring is started and the wear prediction diagram is obtained by calculation.

  For this reason, it is assumed that the wear amount Yn of the rider ring at the accumulated time Xn collected up to now is used, and the wear prediction diagram of the rider ring can be expressed by Equation 1 based on these data.

The slope k of the straight line when it can be expressed by Equation 1 is obtained by the least square method using the data (X1, Y1), (X2, Y2), ..., (Xn, Yn) collected so far. Ask.
Then, the slope k of this straight line can be calculated by Equation 2.

  In addition, as shown in FIG. 5, the calculation of the inclination of the wear prediction line includes a period (1) from mounting the rider ring to the final measurement point (1) and a period of up to two years stored in the computer (2 ) Whichever is shorter is used.

  After obtaining the slope k in this way, as shown in FIG. 4B, a wear prediction line is drawn continuously from the last measurement point, that is, the latest data (Xn, Yn).

  By drawing the wear prediction line in this way, the remaining life time can be calculated from the predetermined wear limit of the rider ring.

  Furthermore, the operating rate can be calculated from the accumulated operating time of the compressor so far and the actual elapsed time, and the life reaching date can be calculated and predicted from the operating rate and the remaining lifetime.

  When collecting data, the latest measurement data is compared with the previous measurement data, and if there is a difference of 0.35 mm or more in the wear amount of the rider ring, an alarm is issued. . This is because the instrument error is 0.2 mm and the thermal expansion change due to the operating temperature is 0.15 mm, but it is necessary to warn that there is a difference in value exceeding the sum of 0.35 mm.

  According to such a rider ring wear prediction method, the wear amount of the rider ring is detected from a change in the distance to the outer peripheral surface of the piston on which the rider ring is mounted, and this detection signal is collected at regular intervals. When the operating time is integrated and the operating time up to the present exceeds the predetermined time, the slope of the wear prediction graph of the wear amount with respect to the operating time is calculated using the collected information of the detection time and wear amount so far. Because, based on this slope, draw a wear prediction diagram from the final measurement point, so that the remaining life until the predetermined wear limit is reached, so life prediction is not performed until the operation time exceeds a predetermined time, As a result, it is possible to predict with high accuracy by avoiding the influence of the measurement accuracy of the wear amount, and after a predetermined time has passed, the wear amount of the wear amount with respect to the operation time is predicted using the collected information of the detection time and the wear amount so far. Calculates the inclination of the diagram, by drawing the wear predicted diagram from the last measurement point on the basis of this inclination, it is possible to determine the remaining service life to reach a predetermined wear limit with high accuracy.

  Further, by collecting the wear detection signal at regular intervals once every 24 hours of the actual operation time, the remaining life can be predicted with the required accuracy.

  In addition, the operating time after the lapse of the predetermined time is set to be after the time when the expected wear amount of the rider ring based on the experience so far exceeds the wear amount detection error. Until the operating time exceeding the time elapses, it is possible to avoid the influence of the detection error by not predicting the remaining life, and to predict the remaining life by calculation with high accuracy.

  Furthermore, since the predetermined time for starting the prediction of the wear amount is set to 1000 hours, based on the experience that after 1000 hours, the wear amount without detection error can be obtained, a highly accurate remainder Life expectancy can be predicted.

  In addition, since the calculation of the slope of the predicted wear diagram is performed by the least square method, the slope of the predicted wear chart can be calculated relatively easily and the remaining life can be predicted with the required accuracy. be able to.

  In addition, after replacing the rider ring, the accumulated operating time used to predict the amount of wear can be changed after the replacement. By predicting the remaining life using, the remaining life can be predicted with high accuracy even after replacement.

1 is an overall schematic configuration diagram according to an embodiment of a rider ring wear measuring apparatus of the present invention; It is sectional drawing of the sensor concerning one Embodiment of the wear measuring apparatus of the rider ring of this invention, and its attachment state. It is a flowchart concerning one embodiment of the wear prediction method of the rider ring of this invention. It is explanatory drawing in the case where it does not draw the wear prediction line concerning one Embodiment of the wear prediction method of the rider ring of this invention, and a case where it draws. It is explanatory drawing in the case of estimating the remaining life concerning one Embodiment of the wear prediction method of the rider ring of this invention. 1 is a longitudinal sectional view of a horizontal reciprocating compressor to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 1a Cylinder liner 2 Piston 3 Piston ring 4 Rider ring 10 Rider ring wear measuring device 11 Sensor 11a Sensor main body 11b Sensor cover 11c Seal part 11d Screw part 12 Sensor mounting hole 12a Seal surface 13 Sensor washer 14 Protection member 15 Reception 16 Transmission box 17 Sensor cable 18 Transmission cable 19 Safety holder 20 Rider ring wear monitoring panel

Claims (8)

A sensor mounting hole is provided through the cylinder side wall facing the outer peripheral surface of the piston on which the rider ring is mounted, and a sensor for detecting the distance from the outer peripheral surface of the piston is mounted in the sensor mounting hole. A receiver is provided, and a transmission box is interposed between the receiver and the sensor ,
The sensor is composed of an eddy current sensor, the tip where the coil of the sensor is located is covered with a non-conductive ceramic sensor cover, and the stainless steel sensor body is considered in consideration of the difference in thermal expansion. Joined with wax to form an explosion-proof structure,
The transmission box includes a termination of a high-frequency current from the receiver, a return current output terminal for feedback, a capacitor for a resonance circuit with the sensor, and a half-bridge for detecting a resonance characteristic change,
The sensor and the transmission box are connected by a sensor cable, and a parallel resonance circuit is formed by the sum of the resonance circuit capacitor in the transmission box and the capacitance of the sensor cable. While detecting the intensity of the eddy current that changes due to the change in the distance to the outer peripheral surface as the inductance change of the coil of the sensor, the inductance change is replaced with a change in resonance characteristics,
The receiver includes a transmitter for supplying a high-frequency current to generate an eddy current in the sensor, an amplifier, a detection circuit, a linearizer, and a bottom hold circuit for holding the minimum value of the AC component of the displacement output from the sensor. And amplifying a detection signal as an inductance change detected as a change in the resonance characteristic, linearizing and outputting a signal following the change in the gap to the outer peripheral surface of the piston as a displacement output, and the bottom hold An apparatus for measuring wear of a rider ring, characterized in that it is configured to perform a bottom hold of an alternating current component of displacement output by a circuit and output a minimum value of a gap as a conversion output to obtain a wear amount of the rider ring. 2. A safety holder is provided between the transmission box and the receiver, which has a low reactance with respect to a high frequency for measurement but has a high reactance with respect to a power supply frequency to form a barrier. The described rider ring wear measuring device. A protective member for protecting the front end of the sensor cover of the sensor is attached to the inside of the cylinder side wall, and a sensor washer for adjusting the position of the front end surface of the sensor is interposed at the base end of the sensor mounting hole. The rider ring wear measuring device according to claim 1 or 2 . The wear amount of the rider ring is detected from the change in the distance to the outer peripheral surface of the piston on which the rider ring is mounted by the rider ring wear measuring device according to any one of claims 1 to 3 , and this detection signal is detected for a predetermined time. Each time, the operating time is accumulated, and the operating time up to the present time exceeds the expected time elapsed when the expected wear amount of the rider ring based on past experience exceeds the detection error of the wear amount . Sometimes, using the collected information of the detection time and the wear amount so far, calculate the slope of the wear prediction diagram of the wear amount with respect to the operation time, draw the wear prediction diagram from the final measurement point based on this slope, A method for predicting the wear life of a rider ring, characterized in that a remaining life until reaching a predetermined wear limit is obtained. 5. The method for predicting the wear life of a rider ring according to claim 4, wherein the wear detection signal is collected once every 24 hours . 6. The method for predicting a wear life of a rider ring according to claim 4, wherein the predetermined time for starting the prediction of the wear amount is set to 1000 hours . The rider ring wear life prediction method according to any one of claims 4 to 6, wherein the slope of the wear prediction diagram is calculated by a least square method. The rider ring according to any one of claims 4 to 7, wherein, after the rider ring is replaced, the operation time used for predicting the wear amount can be changed after the replacement . Wear life prediction method.

Images