JP2019027912A - Abnormality diagnostic device - Google Patents

Abstract

To allow a vibration threshold for abnormality diagnosis to be easily adjusted.SOLUTION: The abnormality diagnostic device diagnoses an abnormality from the detection vibration value of the vibration of a fluid machine, and the monitoring device of the fluid machine controls the fluid machine according to the result of the abnormality diagnosis. The abnormality diagnostic device determines whether the fluid machine is in an adjustable state and adjusts a vibration threshold value as a reference of the abnormality diagnosis.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an abnormality diagnosis apparatus for monitoring an abnormality of a fluid machine such as a compression apparatus.

  Conventionally, fluid machines have been used in a wide range of industries, and techniques for detecting abnormal vibrations, which are predictive phenomena of abnormalities, and stopping fluid machines are known.

  Patent Document 1 discloses an abnormality monitoring device for an air conditioner that is one of applied products of fluid machinery.

[0027] to [0029] of Patent Document 1 include: “... As described above, the air conditioner of the present embodiment includes the housing 2, the air blower 10 provided in the housing 2, and the air blower. The vibration detection means (vibration sensor 103) for detecting the vibration of the device 10 and the blower device 10 include a fan 100 and a motor 101 that drives the fan 100 via a rotating shaft, and a compressor that compresses the refrigerant. 300, including the control of 300, is provided separately from the control device (product control board 500) for controlling the entire air conditioner 1, and diagnoses the abnormality of the blower 10 based on the output from the vibration detection means (vibration sensor 103). An abnormality diagnosis device (abnormality detection control module 501) is provided, and when the abnormality diagnosis device (abnormality detection control module 501) detects an abnormality of the blower 10, the control device (product control board 5). 00), the control device (product control board 500) stops the operation of the blower device 10 when notified from the abnormality diagnosis device (abnormality detection control module 501).
Furthermore, in this embodiment, a sensitivity adjustment switch 601 such as a dip switch or a rotary switch is provided on the abnormality detection control module 501. Since the vibration sensor 103 detects the vibration amount at the sensor mounting position, the detection amount varies depending on the operation specifications and structure of the product, the sensor mounting position, and the like. In other words, there are various product forms such as buildings, stores, equipment, refrigerators, chillers, etc., and the products are different in structure, the type of blower and the number of rotations are different, and the generated vibration is large. In addition, since the thresholds are different, the threshold value for determining an abnormality is also originally different.
If it is designed exclusively for each product like the abnormality detection device shown in FIG. 6, the abnormality determination threshold value may be adjusted. In this embodiment, the abnormality detection part is modularized so that it can be applied to various models. It is a thing. In this case, it is desirable to improve versatility by providing a sensitivity adjustment function. In other words, by providing a function that can adjust the threshold according to the installation status of the product and the user, the applicable range is expanded and versatility is enhanced. By setting it as such a structure, the outdoor unit of the air conditioner which can expand the abnormality detection function of a fan efficiently efficiently can be provided. Is described.

JP 2014-2111143 A

  It is complicated to adjust the abnormal vibration threshold value with a switch for each model as in Patent Document 1, and the adjustment margin of the abnormal vibration threshold value that can be adjusted only with a combination of switches is small. Therefore, it cannot be said that the abnormality detection accuracy can be easily improved.

  In addition, in the case of industrial fluid machines, they are often placed in harsh installation environments (eg, environmental temperature), and the abnormal vibration threshold adjusted before shipment depends on the installation environment even if there is no abnormality in the equipment itself. An abnormal vibration threshold may be exceeded and an abnormality may be detected. Therefore, if there is a monitoring device that can adjust the abnormality detection threshold in the installation environment, the number of erroneous detections can be reduced.

  An object of the present invention is to provide an abnormality diagnosis device with high abnormality detection accuracy of a fluid machine.

  The present invention adds a function of automatically adjusting the abnormal vibration threshold of the abnormality diagnosis apparatus to the above problem.

  ADVANTAGE OF THE INVENTION According to this invention, the abnormality diagnosis apparatus with high abnormality detection precision of a fluid machine can be provided.

1 is a configuration diagram of a fluid machine monitoring system in Embodiment 1. FIG. 1 is a circuit configuration example of an abnormality diagnosis device used for a fluid machine in Embodiment 1. It is a figure which shows the flow of control of the abnormality diagnosis apparatus used for the fluid machine in Example 1. FIG. It is a figure which shows the vibration waveform and driving | running state at the time of normal of the fluid machine in Example 1. FIG. It is a circuit structural example of the abnormality diagnosis apparatus used for the fluid machine in Example 2. FIG. It is a figure which shows the vibration waveform at the time of the normal of the fluid machine in Example 2, the signal waveform of a vibration, and an operation state.

  The present invention adds a function of automatically adjusting an abnormal vibration threshold to an abnormality diagnosis apparatus, and in most cases, abnormality detection accuracy can be easily improved.

  In some cases, however, false detections increased more than before automatic adjustment. This is because industrial fluid machines generate large vibrations depending on the installation environment and operating conditions. That is, in an industrial fluid machine, periodic micro vibrations (micro vibrations having a frequency corresponding to the number of rotations) of a fluid machine driving unit (eg, a motor) and a fluid machine main body (eg, a compressor) are generated, but unloaded. When the load fluctuates greatly, such as during operation and at start / stop, larger or smaller vibrations are generated than during steady operation in the load operation mode. More specifically, the same level of vibration (several times to 10 times) occurs when a mechanical abnormality such as loss of the function of the compressor or locking of the driving means due to abnormality of the mechanical part occurs.

  Therefore, a function for determining whether or not the operating state is suitable for adjusting the abnormality detection threshold is provided in the fluid machine abnormality diagnosis device, and in the case of a state that is not suitable for adjusting the abnormal vibration threshold (for example, a periodic minute vibration state), The function of adjusting the abnormal vibration threshold is provided after the vibration threshold is not adjusted and the state is suitable for the adjustment of the abnormal vibration threshold.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a configuration diagram of a monitoring system for a fluid machine of this embodiment.

  The fluid machine monitoring system includes a power source 1, an electromagnetic switch 2, a thermal relay 3, a motor 4, a compressor body 5, a control device 6, a tank 10, a pressure sensor 11, a check valve 12, a valve 13, and an abnormality diagnosis device 14. Have

  The AC power supplied from the power source 1 is supplied to the motor 4 via the electromagnetic switch 2 and the thermal relay 3, and the compressor body 5 is driven by the motor 4.

  The control device 6 includes a cutoff circuit 7, a microcomputer 8, and a storage circuit 9.

  The microcomputer 8 has a function of receiving signals from the pressure sensor 11 and the abnormality diagnosis device 14 and a function of recording and reading information in the storage circuit 9.

  Further, the microcomputer 8 calculates the information of the pressure obtained from the pressure sensor 11 and controls the shutoff circuit 7 so as to obtain a desired pressure, thereby indirectly controlling the rotation of the motor 4, so that the fluid machine Controls the operation and stop of the.

  The abnormality diagnosis device 14 disposed in the vicinity of the compressor main body 5 monitors abnormal vibration of the compressor main body 5 (or the motor 4), and transmits a signal notifying the occurrence of abnormal vibration to the microcomputer 8.

  When the microcomputer 8 receives a signal notifying the occurrence of abnormal vibration, the microcomputer 8 controls the shut-off circuit 7 to stop the compressor flow main body (or motor).

  The compressed air discharged from the compressor body 5 is temporarily stored in the temporary storage tank 10.

  The temporary storage tank 10 is provided with a pressure sensor 11 for measuring the tank internal pressure.

  The pressure sensor 11 measures the pressure value and transmits pressure information to the microcomputer 8.

  Further, the compressed fluid discharged from the temporary storage tank 10 is supplied to the outside through the check valve 12 and the valve 13.

  FIG. 2 shows a circuit configuration diagram of the abnormality diagnosis device 14.

  The abnormality diagnosis device 14 includes a piezoelectric element 101, an amplifier circuit 102, a filter 103, an envelope detection 104, a microcomputer 108 with an AD converter 105, a storage circuit 109, and a signal output circuit 107.

  The piezoelectric element 101 is a sensor that is arranged in the vicinity of the motor 4 or the compressor main body 5 and measures the vibration of the fluid machine, and outputs the measured vibration value as a signal.

  The amplifier circuit 102 amplifies the output signal of the piezoelectric element 101 for signal processing.

  The signal amplified by the amplifier circuit 102 is connected to the filter 103 and passes only the frequency component necessary for detecting abnormal vibration.

  The signal output from the filter 103 is input to an A / D converter 105 built in the microcomputer 108 via an envelope detection circuit 104 that holds an amplitude signal.

  The storage circuit 109 stores an adjustment history including the vibration amplitude value when the fluid machine is normal, the abnormal vibration threshold value, and the date and time when the abnormal vibration threshold value was adjusted. The date and time of this adjustment history information may be replaced with data indicating whether or not the adjustment history has already been implemented.

  Next, the flow of control of the abnormality diagnosis device 14 is shown in FIG. Regardless of whether the motor 4 is operated or stopped, the abnormality diagnosing device 14 starts operation when the abnormality diagnosing device 14 is energized and reads the adjustment history recorded in the storage circuit 109.

  In the subsequent step 2, it is determined “YES (adjusted)” or “NO (unadjusted)” from the adjustment history, and if “NO” is determined, the abnormal vibration threshold value is adjusted continuously. To do. In this embodiment, only whether or not automatic adjustment has been completed is determined. However, a function for deleting the execution date and time after a certain period has been added, or automatic adjustment within a predetermined period by comparing the execution date and time with the current date and time. It is also within the scope of the present invention to change the function to automatically readjustment by determining whether it has been done. With such a function, periodic readjustment is possible, and therefore, highly accurate adjustment reflecting the secular change of the fluid machine is possible.

  In addition, by using the above functions, a display panel is provided on the fluid machine or abnormality diagnosis device to display whether or not readjustment is necessary, or to generate a warning sound for readjustment “necessary”. It is also within the scope of the present invention to prompt readjustment after 3.

  In step 3, the A / D converter 105 converts the electrical signal into a digital signal and reads it.

  In the subsequent step 4, it is determined whether the fluid machine (the motor 4 or the compressor main body 5) is in one of (1) an adjustable state and (2) an unadjustable state. In this embodiment, the adjustable state (1) is a state in which periodic micromotion occurs. In this embodiment, in order to simplify the apparatus configuration, it is determined whether or not it is in an adjustable state using fluid mechanical vibration as an input.

  For this reason, when the 0th voltage value V0 (for example, V0 = 0V) exceeds the 1st voltage value V1 (upper limit value, for example, about + 20% of the voltage of vibration that can be normally generated) in step 5, the motor is operated. Since it is the start time (when the fluid machine is started), it is determined that the adjustment is impossible, and the process returns to step 3 to continuously monitor the vibration signal. After the start of the operation, until the vibration signal converges to the vibration signal of the steady operation that becomes the first voltage value V1 or less, that is, until the start-up operation is completed, it is determined in step 6 that it is the start-up time. Return to and continue to monitor the vibration signal. On the other hand, when it is not determined that the vehicle is being activated, it is determined that the activated state is over and the steady operation state is reached, and the process proceeds to step 7.

  Here, when the compressor 5 of the fluid machine is an unloader type, the unload operation has less vibration than the load operation. For this reason, in order to increase the accuracy, if the vibration signal is smaller than V2 without including the unload operation in the steady state, it is determined that the adjustment is not possible during the unload operation, and the vibration signal Is in the range from V1 to V2, it is determined that an adjustable state has been reached. Thus, providing the lower limit is also within the scope of the present invention.

  In step 7, a vibration signal during operation is acquired, and in step 8, a normal vibration value is calculated. In the calculation of step 8, the maximum value of vibration in the steady state of the storage circuit 109 is recorded or updated. Here, abnormal values may be input to the vibration signal due to impacts from outside the fluid machine, electrical noise, etc., so abnormal input is performed by processing such as abnormal value cutting or maximum time averaging. It is desirable to perform signal removal. In step 8, when the maximum value of vibration is not updated for a certain period, it is determined that the maximum value of normal vibration value has been calculated, and the process proceeds to next step 9.

  In step 9, an abnormal vibration threshold value that is a criterion for abnormal vibration is calculated from the maximum value of normal vibration obtained in step 8. Here, when an abnormality occurs in the fluid machine, an abnormal vibration several times to several tens of times higher than a normal vibration occurs. Therefore, the abnormal vibration threshold is estimated several times the normal vibration in the steady state by estimating the operating state at the maximum load while taking into consideration the level of vibration, the degree of breakage, and the impact on other equipment and production due to breakage of the fluid machine. (For example, 3 to 5 times), the accusation is set and stored as a new abnormal vibration threshold value in the memory circuit 109 in step 10.

  Finally, in step 11, the information of the adjustment history of the storage circuit 109 used also in step 1 is updated, and the process proceeds to step 12 to monitor the abnormality of the fluid machine.

  Thus, by measuring only the vibration of the fluid device, it is possible to determine the operating state, measure the vibration value in the steady state, adjust the abnormality determination threshold value, and determine the abnormality.

  Thus, according to the present embodiment, the abnormality diagnosis device 14 can set a threshold value for abnormality determination based on the value of the steady state vibration detection signal detected by the piezoelectric element 101 that detects vibration. When it is determined that there is an abnormality in the motor 4 that is the fluid machine drive unit or the compressor 5 that is the fluid machine body, the operation of the fluid machine can be stopped quickly.

  Therefore, peripheral devices such as a dip switch, a rotary switch, and a serial communication function (communication connector or circuit) are not required for setting the abnormal vibration threshold, and an inexpensive abnormality diagnosis device 14 can be provided. Further, the size of the detector is increased, and the number of work steps required for writing the threshold value can be reduced.

  In this embodiment, an example in which an abnormality signal is output from the abnormality diagnosis device 14 to the control device 6 to indirectly stop the fluid machine has been described. The abnormality diagnosis device 14 can also be applied to the fluid machine by directly operating the electromagnetic switch 3. For this reason, almost no structural change or refurbishment of the motor 4 or the fluid machine is required, so that the abnormality diagnosis device 14 according to the present embodiment can be easily added to the existing compression device.

  Furthermore, in this embodiment, the determination threshold value for abnormal vibration is determined from the vibration maximum value in the steady state, but in addition to this, the determination threshold value may be determined from two values of vibration values in the unsteady state. Good

  Next, FIG. 5 shows a circuit configuration example of the second embodiment. The feature of the present embodiment is that the A / D converter 105 reads signals from the two envelope detection circuits 104 and 106. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

    The abnormality diagnosis device 54 is configured in substantially the same manner as the abnormality diagnosis device 14 according to the first embodiment. For this reason, the abnormality diagnosis device 54 performs the calculation processing of the vibration value of the fluid machine and the calculation processing of the abnormality determination threshold shown in FIG. 3 as in the first embodiment.

  However, the abnormality diagnosis device 54 uses the vibration signal of the gas fluid from which noise has been removed by the filter 103 to calculate the amount of time change of one of the envelope detection circuits 104 having different time constants and to estimate the operating state, The envelope detection circuit 106 is measured for calculation of an actual vibration signal.

  FIG. 6 shows a normal vibration waveform, a vibration signal waveform, and an operating state of the fluid machine in the second embodiment. Specifically, when the fluid machine is started, a detection signal change amount that is a difference from the previous value of the envelope detection signal 1 is calculated, and the detection signal change amount (difference) is equal to or greater than a predetermined value. In this case, it is determined that the readjustment is impossible due to the change of the operation mode, and the readjustment is not performed until the readjustment is possible. Here, the operation mode change state refers to a change to a non-load operation mode or a load operation, such as a change from stationary to normal operation, a change from load operation to unload operation, a change from steady operation to stop, etc. Indicates the state during the change to.

  Next, as the fluid machine passes a predetermined time from the switching state and approaches the state of steady operation, the detection 1 signal change amount gradually decreases and the occurrence frequency also decreases. Accordingly, when the detection 1 signal change amount becomes a predetermined value (for example, 50 mV) or less and a predetermined time has elapsed, it is determined that the operation has shifted to the steady operation, and the envelope detection signal 2 is used to calculate the vibration value of the fluid machine. And the abnormality determination threshold calculation process and abnormality monitoring.

  Thus, the second embodiment can provide the same effects as those of the first embodiment. In the second embodiment, a more accurate vibration value can be calculated by calculating vibration from the envelope detection 2 signal having a short time constant.

  In each of the above embodiments, the signal filter 103 and the envelope detection circuits 104 and 106 are configured by hardware. For example, the digital signal read by the A / D converter 105 is filtered by software. The function of envelope detection may be realized.

DESCRIPTION OF SYMBOLS 1 ... Power supply, 2 ... Electromagnetic switching device, 3 ... Thermal relay, 4 ... Motor, 5 ... Fluid machine, 6 ... Control apparatus, 8 ... Microcomputer, 10 ... Tank, 11 ... Pressure gauge, 12 ... Check valve, 13 ... Valves 14, 54 ... Abnormality diagnosis device, 101 ... Vibration detecting means, 102 ... Signal amplification circuit, 103 ... Filter, 104 ... Envelope detection circuit, 105 ... A / D converter, 106 ... Envelope detection circuit, 108 ... Microcomputer 109 ... Memory circuit

Claims (10)

In the abnormality diagnosis device for diagnosing abnormality from the measured vibration value of the vibration of the fluid machine,
A function of determining whether or not the fluid machine is in an adjustable state;
An abnormality diagnosing device that adjusts an abnormal vibration threshold value that serves as a reference for abnormality diagnosis. In claim 1,
An abnormality diagnosis device that determines whether or not the fluid machine is in an adjustable state based on the measured vibration value. In claim 1 or 2,
The abnormality diagnosing apparatus according to claim 1, wherein the state in which the fluid machine can be adjusted does not include a start-up time of the fluid machine. In claim 3,
An abnormality diagnosis apparatus, wherein the abnormal vibration threshold is adjusted after the start-up operation is completed, not during the start-up operation. In claim 1 or 2,
The abnormality diagnosis apparatus according to claim 1, wherein the state in which the fluid machine can be adjusted does not include the unload operation. In claim 5,
The abnormality diagnosis apparatus characterized in that the adjustment of the abnormal vibration threshold is not performed during the unload operation but after the unload operation. In claim 1 or 2,
The abnormality diagnosing apparatus according to claim 1, wherein the state in which the fluid machine can be adjusted does not include a change in the operation mode of the fluid machine. In claim 7,
The abnormality diagnosis apparatus according to claim 1, wherein the adjustment of the vibration threshold value in the abnormal state is performed after the operation mode changing operation is completed. In claim 7,
Generating two or more types of signals having different time characteristics from the measured vibration values;
One of the two types of signals is used for estimation when the operation mode is changed,
An abnormality diagnosis apparatus, wherein the other of the two types of signals is set to the steady state frequency. In claim 2,
The abnormality diagnosing apparatus characterized in that the detection means estimates an operating state of the fluid machine at a maximum load from the vibration value in the steady state and calculates a maximum vibration value in the steady state of the mechanical device.

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