JPH07128134A - Monitoring-diagnosing apparatus for rotary machine - Google Patents

Abstract

PURPOSE:To early detect a malfunction sign before a vibrating state of an apparatus reaches a limited value and to improve reliability of monitoring by comparing a vibration value with a threshold value corresponding to a process amount to be decided. CONSTITUTION:A vibration detector 1 detects a vibration of an apparatus to be monitored and converts it to an electric signal. An operating parameter detector 4 detects an operating state such as a rotating speed, etc., of the apparatus, and converts a quantity of a state for representing an operating parameter to an electric signal. Electric signals generated from the detectors 1, 4 are input to a threshold comparator 5, and a note value, an alarm value corresponding to the parameter of the apparatus to be measured and previously stored in a threshold value storage unit 6 are extracted. Then, the comparator 5 compares a vibration value with the note value, the alarm value, and transmits an electric signal to a display unit 3 when the vibration value exceeds the note value or the alarm value. The unit 3 which receives the value displays correspondingly a note warning or an alarm warning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condition monitoring device for rotating equipment for early detection of abnormal signs occurring in equipment constituting a plant.

[0002]

2. Description of the Related Art A monitoring and diagnosing device is used, for example, for monitoring vibration values of constituent equipment in a nuclear power generation facility and for issuing an alarm to an operator when a vibration value to be monitored deviates from a set value. . Hereinafter, a conventional example of the monitoring and diagnostic device will be described with reference to FIG. In FIG. 18, the conventional monitoring / diagnosing device is mainly composed of a vibration detector 1, an alarm setting device 2, and a display device 3. The vibration detector 1 is a detector that converts the measured amount of the monitored object into an electric signal, and is connected to the alarm setting device 2. A display device 3 is connected to the alarm setting device 2 and transmits a contact signal to the display device 3 when the electric signal received from the vibration detector 1 exceeds a preset set value. The display device 3 receives the contact signal and displays an alarm. Normally, the operating limit of the vibration value is adopted as the set value in the case of rotating equipment.

[0003]

In the above-mentioned conventional monitoring and diagnosing device, since the alarm is displayed only when the vibration value of the plant constituent equipment exceeds the operation limit point, it is necessary to take countermeasures from the occurrence of the alarm to taking measures. Due to the lack of time, I had to shut down the equipment and plant for safety reasons. Also,
Depending on the malfunction of the equipment, the alarm may be displayed for the first time when it progresses significantly, so the detection is delayed, the malfunction spreads to other equipment, and in the worst case, it causes large damage to the entire plant. There was a possibility.

On the other hand, in a rotating device, even in a normal operating condition, the vibration value often differs depending on the operating condition of the device. For example, in a variable speed rotating device, resonance may occur when the eigenvalue of the system coincides with the rotation synchronization component or its harmonic component, and the vibration value may increase. Therefore, even in a rotating machine at a constant speed, vibration often increases when the flow rate is smaller than the rated state. Therefore, if the alarm set point is set low, there is a possibility that an erroneous alarm will be issued in a region where the vibration value is high. The present invention has been made in response to such conventional circumstances, and an object thereof is to detect a change from a normal state at an early stage as an abnormal sign before the vibration state of a device reaches a limit value. The present invention provides a monitoring / diagnosing device having high monitoring reliability.

[0005]

In order to achieve the above object, in the monitoring and diagnosing device of the present invention, in the invention according to claim 1, a vibration detector for detecting a vibration value generated from a device to be monitored; A process amount detector that detects a process amount that indicates the operating state of the monitored device, and a threshold value comparison device that makes a comparison determination between the vibration value and a preset threshold value corresponding to the process amount. And a threshold value storage device which is connected to the threshold value comparison device and stores a threshold value set corresponding to the process amount.

According to the second aspect of the present invention, the threshold value set corresponding to the process amount is equal to the average value of the vibration values corresponding to the process amount indicating the operating state during normal operation, and this average value. The monitoring diagnostic apparatus according to claim 1, wherein the monitoring diagnostic apparatus is calculated from the variation of the vibration value.

According to the third aspect of the present invention, the threshold value set corresponding to the process amount is the rotational angular velocity ω of the monitored device and the coefficient a obtained by the least square method.
The monitoring diagnostic apparatus according to claim 1, wherein the monitoring diagnostic apparatus is calculated by the following expression expressed using b and c.

[0008]

[Equation 2]

In a fourth aspect of the present invention, the threshold value set corresponding to the process amount divides the operating range of the monitored device into a plurality of operating regions based on the process amount. The monitoring diagnostic apparatus according to claim 1 or claim 2 or claim 3, wherein the monitoring diagnostic apparatus is calculated in the operating range.

In the fifth aspect of the present invention, the operating range is such that a slope of a straight line connecting the measurement points of the minimum process amount to the measurement points is calculated, and the first range extends to the measurement point where the slope starts to increase. Then, the slope of the straight line connecting the measurement points from which the slope starts to increase to each measurement point is calculated again, and the area up to the measurement point at which the slope starts to increase again becomes the second area. By repeating this, the area is divided. The present invention provides a monitoring / diagnosing device according to claim 4.

According to a sixth aspect of the present invention, a vibration detector that detects a vibration value and a phase angle of vibration generated from the monitored device, and a process amount detector that detects a process amount indicating an operating state of the monitored device. A threshold value comparing device for making a comparison judgment with a preset threshold value corresponding to the process amount with respect to the vibration value and the phase angle of the vibration, and connected to the threshold value comparing device. And a threshold value storage device for storing a threshold value set corresponding to the process amount.

According to a seventh aspect of the present invention, the threshold value set corresponding to the process amount is a vibration value corresponding to the process amount indicating an operating state during normal operation and an average value of the phase angle of the vibration, The monitoring diagnostic apparatus according to claim 6, wherein an average value of these values is calculated from the variation of the vibration value and the phase angle.

According to the present invention, the threshold value set corresponding to the process amount divides the operating range of the monitored device into a plurality of operating regions based on the process amount, and divides the operating range into a plurality of operating regions. The monitoring diagnostic device according to claim 6 or claim 7, wherein the monitoring diagnostic device is calculated in the operating range.

[0014]

In the monitoring and diagnosing device having the above structure, the threshold comparing device compares the alarm value and the caution value corresponding to the process amount (hereinafter referred to as operating parameter) indicating the operating state of the device with the actual vibration value, and If the value deviates from the caution value, a warning is displayed on the display device, and if the value deviates from the warning value, a warning is displayed on the display device.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the monitoring and diagnosing device according to the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram schematically showing a first embodiment of a monitoring and diagnosing device according to the present invention. In FIG. 1, the vibration of the equipment to be monitored is detected by the vibration detector 1 and converted into an electric signal. Further, the operation parameter detector 4 detects an operation state such as the rotation speed of the device, and the state quantity representing the operation parameter is also converted into an electric signal by the operation parameter detector 4. The electric signals generated by the vibration detector 1 and the operating parameter detector 4 are input to the threshold comparison device 5. The threshold value storage device 6 and the display device 3 are connected to the threshold value comparison device 5. This threshold storage device 6
The caution value and the alarm value corresponding to the operation parameter of the device to be monitored are stored in advance.

In the monitoring and diagnosing device thus constructed, for example, the vibration value of the pump and the operating parameter of the pump are periodically sampled during the operation of the plant and transmitted to the threshold comparing device 5 as an electric signal. It The threshold value comparison device 5 extracts a caution value and an alarm value stored in the threshold value storage device 6 corresponding to the operating parameters of the pump, which is the device to be monitored. Next, the vibration value is compared with the alarm value and the caution value, and if the vibration value exceeds the alarm value or the caution value, an electric signal is transmitted to the display device 3 in each case. The display device 3 which has received this electric signal displays an alarm or a warning corresponding to each case.

Now, the relationship among the measured vibration value, alarm value and caution value will be described with reference to FIG. FIG. 2 is a graph showing a general relationship between the operating parameter and the vibration value generated in the device, the alarm value, and the caution value. The vertical axis represents the vibration value and the horizontal axis represents the operating parameter p. In the figure, A is a measured vibration value, B is an alarm value indicating an operating limit, and C is a normal vibration state average value and a caution value obtained from its variation.

In the present embodiment, the caution value C changes depending on the operating parameter p of the rotating machine. Here, as the operation parameter p, it is preferable to use the rotation speed for a variable speed rotating device and the flow rate, the differential pressure or the discharge pressure for a constant speed rotating device such as a pump.

Next, a first method of calculating a caution value used in the monitoring and diagnosing device according to the present invention will be described with reference to FIG. Similar to FIG. 2, FIG. 3 shows the vibration value on the vertical axis and the operating parameter p on the horizontal axis. In the figure, A is a measured vibration value, C is a caution value, D is a quadratic curve in which the vibration value is regressed by operating parameters using the least square method, and E is each measured data and this regression curve. It is a curve obtained by adding the standard deviation σ calculated from the difference between and to the regression curve. The caution value is thus obtained by adding a real multiple of the standard deviation to the quadratic regression curve of the vibration value. This multiple value differs depending on the equipment to be monitored and the standard deviation of the vibration value, but normally 3 to 5 is desirable. The caution value C calculated in this way is expressed by the following equation for the operating parameter p.

[0020]

[Equation 3]

Here, a, b and c are coefficients of the regression curve, σ is the standard deviation and n is a coefficient by which the standard deviation is multiplied. As shown in FIG. 4, the threshold value storage device stores the alarm value and the values of a, b, and d described above, and with respect to the operation parameter p transmitted from the parameter detector 4,
The caution value C is calculated using each coefficient and compared with the actual vibration value.

In the present embodiment, since the caution value C is calculated from the average value and the variation of the normal vibration state and is changed corresponding to the parameter indicating the operating state of the rotating equipment, the generation of erroneous signals is small, Early warning signs can be detected before an alarm is issued, and reliable monitoring can be performed.

Next, a second method of calculating a caution value in the first embodiment of the monitoring and diagnosing device according to the present invention will be described with reference to FIG. 5, the same measured quantity and definition curve as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 5 shows a rotating machine having a plurality of resonance points, for example, a rotating machine of variable speed, and the entire operating region cannot be accurately approximated by one type of regression curve, or the rotating machine has a variation depending on the operating state. The relationship between the vibration value A and the operating parameter p is shown. In this calculation method, the operating range is divided into a plurality of regions, the vibration value A is regressed by a polynomial of the operating parameter p for each region, and a value obtained by adding a real multiple of the standard deviation to this regression curve D is a caution value. It is designated as C.

FIG. 6 shows the data structure when the caution value C according to the present calculation method is stored in the threshold value storage device 6.
Coefficients a, b, and c for calculating the caution value C are stored for each operating parameter p range, and the threshold value storage device 6
Calculates the caution value C by the following equation from each coefficient stored in the corresponding area of the operation parameter p transmitted from the operation parameter detector 4.

[0026]

[Equation 4] When there is a region including the resonance point, it is possible to regress with the following equation to calculate the caution value.

[0027]

[Equation 5]

Here, a, b and c are coefficients of the regression curve, and p is an operating parameter. Furthermore, a third calculation example of the caution value C in the first embodiment will be described with reference to FIG. In FIG. 7 as well, the same measured quantity and definition curve as those in FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted. In this calculation example, the operating range is divided into a plurality of regions, and the vibration value A is regressed by the operating parameter p for each region.
A value obtained by adding a real number times the standard deviation to the maximum value of the regression curve D in each divided region is set as the caution value C.

A method of dividing these operating parameters p into regions will be described with reference to FIGS. 8 and 9. FIG. 8 shows a procedure for dividing an area. First, a moving average is taken for the vibration value to smooth the data. For the smoothed data,
As shown in FIG. 9, the minimum data v of the operating parameter p
The gradient between 1 and each data is calculated. As shown in the figure, the gradient is almost constant in the region where the vibration value increases at a substantially constant rate, but the gradient becomes large in the region where the vibration value suddenly increases. The point v2 at which this gradient starts to increase is defined as the division point of the area.

Next, the point v2 at which the gradient starts to increase.
Similarly, the gradient with each data is calculated. As shown in FIG. 9, when the vibration value has a maximum value, the gradient shows a substantially constant value, then passes through the peak v3, then temporarily decreases, and after passing the minimum value, shows a tendency to increase again. . The point v4 that starts to increase again is set as the division point of the next area. In this way, the gradient from each start point of each area is calculated, and the point where the gradient becomes large is used as the division point to perform area division.

Next, a second embodiment of the present invention will be described with reference to FIGS. In this embodiment, a monitoring / diagnosing device having a caution value for a monitoring index (hereinafter referred to as a vibration vector) in which a vibration value and a phase angle are combined is shown. In the monitoring / diagnosing device that uses the vibration vector, it is possible to detect from the change in the phase angle, even if there is a possibility that the change in the vibration value may not appear, such as a partial defect of the rotating body structure.

In the present embodiment, the vibration value and the phase angle are independently regressed by the operating parameter p, and the value obtained by adding and subtracting the real multiple of the standard deviation to the regression curve is used as the caution value C1 and the phase angle for the vibration value. Is set to C2. Figure 1
As shown in FIG. 1, in the diagram in which the vibration amplitude is in the radial direction and the phase angle is in the circumferential direction (hereinafter referred to as a vibration vector diagram), this region X is shown as a fan shape, and this fan shape depends on the operating state of the equipment. , For example, from X1 to X2. If there is data inside the fan shape, it is normal, and if there is data outside it, it is judged that there is an abnormal sign.

Also in the second embodiment, it is possible to divide the operating range of the equipment into a plurality of areas and set the caution values C1 and C2. FIG. 12 shows an example of the structure of data stored in the threshold value storage device 6 in the second embodiment. In the present embodiment, the threshold value storage device 6 stores, in each operating region, coefficients of curves of four caution values indicating the upper limit and the lower limit of the vibration value and the phase angle, a1, b1, c1min, c1ma.
x, a2, b2, c2min, c2max are stored. The threshold value storage device 6 calculates the caution values C1 and C2 from the vibration value of the caution value in the region to which the operation parameter p corresponds, the coefficient of the function indicating the upper limit value and the lower limit value of the phase angle, and the actually measured vibration value. , It is determined whether the phase angle is included in or out of the range of the caution value.

FIG. 13 to FIG. 15 show a second calculation example of the caution value of the vibration vector in the second embodiment of the present invention. In this calculation example, first, as shown in FIG.
And the phase angle Θ, the central value (Am
(P), Θm (p)) is approximated by a polynomial of the operating parameter p using the least squares method. Next, as shown in FIG. 14, the distance Ri between the center of the vibration vector and the actually measured vibration vector (Ai, Θi) in each operating parameter p is calculated by the following equation.

[0035]

[Equation 6] Further, as shown in FIG. 15, the distance Ri is re-regressed with the driving parameter p, and a value Rm obtained by adding a real number multiple of the standard deviation Rσ of the distance to the regression curve RD is set as a caution value of the distance. In the vibration vector diagram, as shown in FIG. 16, the central value of the vibration vector is (Am (p),
A region having a radius Rm in Θm (p)) is displayed as a circle, and the radius of the circle changes as the center of the circle moves depending on the operating state of the device.

Also in this embodiment, it is possible to divide the operating range of the equipment into a plurality of areas, in which case FIG.
As shown in FIG.
The coefficient of the regression curve showing m, Θm) and the coefficient of the caution value of the distance Rm are stored.

The threshold comparison device 5 determines the vector center (Ai, Θi) for the operation parameter p transmitted from the operation parameter detector 4 by using each coefficient stored in the threshold storage device 6. The distance Ri from the vector center is calculated, and the result is compared with Rm corresponding to the operating parameter p, and it is determined that there is a normal sign when Ri <Rm and an abnormal sign when Ri> Rm.

[0038]

As described above, in the monitoring and diagnosing device of the present invention, the change in the vibration amount of the plant component equipment from the normal operating state is detected, and the abnormality sign is detected early, so that the operating limit of the equipment is limited. In addition to the alarm value indicating, the normal vibration value has an average value and a caution value obtained from the variation, and since this caution value changes according to the operating state of the equipment, a false alarm is generated. Therefore, it is possible to provide a monitoring device that can detect an abnormal sign at an early stage, and improve the reliability of monitoring as well as the operation rate and reliability of the plant.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment according to a monitoring / diagnosing device of the present invention.

FIG. 2 is an explanatory diagram related to the operation of the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a first calculation method of an attention value according to the first embodiment.

FIG. 4 is an explanatory diagram of a threshold value storage device according to the first embodiment.

FIG. 5 is an explanatory diagram of a second method of calculating a caution value according to the first embodiment.

FIG. 6 is an explanatory diagram of a configuration of a threshold value storage device in a second method of calculating a caution value.

FIG. 7 is an explanatory diagram of a third method of calculating an attention value according to the first embodiment.

FIG. 8 is a procedure diagram of an operation parameter region dividing method in a third caution value calculating method.

FIG. 9 is an explanatory diagram of a region dividing method for operating parameters in a third method for calculating a caution value.

FIG. 10 is a first caution value related to the second embodiment of the present invention.
Explanatory diagram of the calculation method of.

FIG. 11 is a first caution value related to the second embodiment of the present invention.
Explanatory diagram of the calculation method of.

FIG. 12 is an explanatory diagram of a configuration related to a threshold value storage device in a first method of calculating an attention value according to the second embodiment.

FIG. 13 is an explanatory diagram of a second calculation method of a vibration vector caution value according to the second embodiment of the present invention.

FIG. 14 is an explanatory diagram of a second calculation method of a vibration vector caution value according to the second embodiment of the present invention.

FIG. 15 is an explanatory diagram of a second calculation method of a vibration vector caution value according to the second embodiment of the present invention.

FIG. 16 is an explanatory diagram of a second calculation method of a vibration vector caution value according to the second embodiment of the present invention.

FIG. 17 is an explanatory diagram of a configuration related to a threshold value storage device in a second method of calculating an attention value according to the second embodiment.

FIG. 18 is a configuration diagram of a conventional example of a monitoring and diagnostic device.

[Explanation of symbols]

1 ... Vibration detector 2 ... Alarm setting device 3 ... Display device 4 ... Operating parameter detector 5 ... Threshold value comparison device 6 ... Threshold value storage device

Claims (8)

[Claims] 1. A vibration detector for detecting a vibration value generated from a monitored device, a process amount detector for detecting a process amount indicating an operating state of the monitored device, and a process amount for the vibration value. And a threshold value comparison device for making a comparison judgment with a preset threshold value corresponding to, and storing the threshold value set corresponding to the process amount connected to the threshold value comparison device. And a threshold value storage device. 2. The threshold value set corresponding to the process amount is an average value of vibration values corresponding to the process amount indicating an operating state during normal operation, and this average value is calculated from the variation of the vibration values. The monitoring diagnostic apparatus according to claim 1, wherein the monitoring diagnostic apparatus is calculated. 3. The threshold value set corresponding to the process amount is a rotational angular velocity ω of the monitored device and a minimum value of 2.
2. The calculation according to the following equation expressed using the coefficients a, b, and c obtained by multiplication.
The monitoring and diagnostic device described. [Equation 1] 4. The threshold value set corresponding to the process amount is calculated in each operating region by dividing the operating range of the monitored device into a plurality of operating regions based on the process amount. The monitoring diagnostic apparatus according to claim 1, 2 or 3, wherein: 5. The operation range is such that the slope of a straight line connecting the measurement points of the minimum process amount to the measurement points is calculated and the first area extends to the measurement point where the slope begins to increase, and the slope increases. It is characterized in that the gradient of a straight line connecting from the measurement point to be started to each measurement point is calculated again, and the point up to the measurement point where the gradient starts to increase again is set as the second area, and the area is divided by repeating this. The monitoring and diagnostic device according to claim 4. 6. A vibration detector that detects a vibration value and a phase angle of vibration generated from a monitored device, a process amount detector that detects a process amount indicating an operating state of the monitored device, and the vibration value and A threshold value comparison device for making a comparison judgment with a preset threshold value corresponding to the process amount with respect to the phase angle of the vibration, and corresponding to the process amount connected to the threshold value comparison device. And a threshold value storage device for storing the threshold value set by the monitoring diagnostic device. 7. The threshold value set corresponding to the process amount is a vibration value and an average value of the phase angle of the vibration corresponding to the process amount indicating an operating state during normal operation, and the average value of these values. 7. The monitoring / diagnosing device according to claim 6, wherein the monitoring / diagnosing device is calculated from variations in the vibration value and the phase angle. 8. The threshold value set corresponding to the process amount is calculated in each operation region by dividing the operation range of the monitored device into a plurality of operation regions based on the process amount. The monitoring / diagnosing device according to claim 6 or 7, wherein: