JPH0343604A - Abnormality diagnosis for turbo type fluid unit - Google Patents

Abstract

PURPOSE:To facilitate determination of a cause of vibration of a fluid unit by detecting a vibration level of the fluid unit, extracting applicable vibration level data from fluctuation factors of fluid to generate vibration at the fluid unit, and comparing them with actual data. CONSTITUTION:For execution for a cenrifugal pump 1 for transferring low temperature liquefied gas such as LNG and LPG, the pump 1 is provided with a vibration acceleration senser 2, a rotor senser 3, in addition to a temperature senser 6, a pressure senser 7, and a flow senser 8 relating to fluid on the suction side, and a line pressure senser 10. At a computation processing device 11, when the pump 1 vibrates in its operation to make its vibration level L1 larger than a critical vibration level, a vibration level L2 at the time when the pump 1 itself has no abnormality is extracted from a memorizing part 12 corresponding to a detected value from each senser. For L1>L2, it is judged to be a vibration by an abnormality of the pump 1 itself, while for L1<L2, it is judged to be a vabration caused by the condition quantity of fluctuation factors of fluid.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a turbo-layer fluid R device such as a centrifugal pump, and particularly to a turbo-type fluid device that detects the vibration level of an Il device to diagnose equipment abnormalities. This invention relates to an abnormality diagnosis method.

[Prior Art] Generally, as a device for diagnosing an abnormality in a fluidic device, a system is known that detects the vibration level of the fluidic device and determines that the device is abnormal when the detected value exceeds a set value. On the other hand, turbo fluid equipment such as centrifugal pressure machines, radial turbines, axial flow compressors, and axial flow turbines may vibrate during operation not only due to abnormalities in the turbo equipment itself, but also due to the operating conditions of the equipment. do.

Abnormalities in the turbo equipment itself include around the rotation axis, bearing bush wear, one rotation imbalance, contact between rotating parts, etc. The above operating conditions include the fluid temperature, pressure, flow rate, etc. on the intake side of the turbo equipment. This is the fluid pressure at discharge opening, etc.

In other words, even if the equipment itself is completely normal, turbo equipment may experience surging or surging depending on the various operating conditions mentioned above.
Cavitation etc. may occur and vibration may occur.

[Problems to be Solved by the Invention] Incidentally, there are few turbo devices whose operating conditions are constant, and many whose operating conditions change from moment to moment.Therefore, vibrations may occur in the turbo devices during operation. Even if
It is difficult to immediately determine whether the vibration is due to an abnormality in the turbo equipment itself or whether it is due to the operating conditions of the equipment.

The present invention was devised in consideration of the above-mentioned circumstances. When vibration occurs in turbo fluid equipment during operation, it is possible to determine whether the vibration is due to an abnormality in the equipment itself or due to the operating conditions of the equipment. The purpose of the present invention is to provide a method for diagnosing abnormalities in turbo-type equipment, which determines abnormality by determining whether or not the object is present.

[Means for Solving the Problems] In order to achieve the above object, the present invention stores vibration level data for each fluid fluctuation factor that causes vibration in turbo fluid equipment, and stores vibration level data for each fluid fluctuation factor that causes vibration in turbo fluid equipment. detects the vibration level of , and when this detected value exceeds the set level,
The state of the fluctuation factor is measured, the corresponding vibration level data is extracted, and when the detected value is larger than the data value, it is determined that the device is abnormal.

[Function] When a vibration level higher than the set level is detected in the turbo-type fluid equipment during operation (this is taken as the detected value), first, the state of the fluid fluctuation factor that causes vibration in the turbo-type fluid equipment is checked. Measure.

Then, a vibration level data value corresponding to the state of the fluctuation factor is extracted from the stored vibration level data.

This data value represents the vibration level of the device in the above fluctuation factor state when there is no abnormality in the device itself, and when this data value is larger than the above detected value, it is determined that the vibration is caused by a device abnormality. .

Conversely, if the detected value is not larger than the data value, it is determined that the vibration is caused not by an abnormality in the device itself but by the state of a variable factor.

Therefore, it is possible to determine whether the vibrations of the turbo fluid device are due to an abnormality in the device itself or to fluctuation factors in the fluid.

[Example code] An embodiment of the present invention will be described with reference to the accompanying drawings.

Using a centrifugal pump as an example of the turbo laminar flow #:t1i device, a method for diagnosing an abnormality in a centrifugal pump will be described below.

Figure 2 shows that LNG (liquefied natural gas) is similar to LPG (
6 shows a centrifugal pump 1 used for conveying low-temperature liquefied gas such as liquefied petroleum gas (liquefied petroleum gas). , a rotation speed sensor 3 that detects the rotation speed N of the impeller of the pump 1, and a blade angle sensor 4 that detects the blade angle α of the impeller are provided. In addition, the suction pipe 5 of the pump 1 has a temperature T and a pressure P of the suction side fluid, which are fluctuation factors of the fluid that cause vibrations in the pump 1.

Temperature sensor 6 and pressure sensor 7 that respectively detect the flow rate Q
．． A flow rate sensor 8 is attached, and a discharge pipe 9 of the pump l is attached.
A line pressure sensor 10 is attached to detect the line pressure A of the discharge (river fluid) which is the above-mentioned fluctuation factor.

These sensors 2, 3.4, 6, 7, 8.10 are each connected online 15 to the processing unit 11. This arithmetic processing device 11 has a storage section 12,
This storage unit 12 stores information about the pump 1 when there is no abnormality in the pump 1 itself when the above fluctuation factors change to various states.
vibration level data is stored.

Further, the suction pipe 5 is provided with a valve 13 located upstream of the sensor 6.7.8 attached to the suction pipe 5 to change the suction flow rate.
A method for diagnosing an abnormality in a pump 1 when operating a centrifugal pump 1 consisting of zero or more configurations, which is provided with a valve 14 located downstream of a sensor 10 attached to the discharge pipe 9 to change the discharge flow rate. is shown in Figure 1.

When the centrifugal pump 1 is operated, the pump 1 not only vibrates due to abnormalities in the pump 1 itself, such as abrasion of the rotating shaft and bearing bushes, but also due to fluctuations in the fluid, such as the suction temperature T.

It also vibrates depending on the suction pressure P1, the suction flow rate Q, the discharge line pressure A, etc., and also due to the blade angle α of the impeller of the pump 1 and the rotation speed N of the impeller.

The abnormality diagnosis method shown in Fig. 1 determines whether the vibrations of the pump 1 during operation are caused by an abnormality in the pump 1 itself or by factors such as fluctuations in the fluid. It is.

As shown in the figure, first, the centrifugal pump 1 is operated, and the vibration acceleration sensor 2 provided on the pump 1 detects the pump l.
The vibration acceleration of the pump 1 is detected, and the vibration level L1 of the pump 1 is detected. In this embodiment, an overall value (total vibration level value) is used as this vibration level 1 value.

This vibration level 1 value is input to the arithmetic processing unit 11 online 15, and ? It is compared with the critical vibration level Lc set in the f4 calculation processing device 11.

At this time, if Ll>Lc, that is, if the pump 1 vibrates greatly and the detected vibration level 1 value is larger than the set critical vibration level Lc value, the pump 1, the suction pipe 5 and the discharge pipe Each sensor 3, 4 .
6, 7.8.10, detect the suction temperature T, suction pressure P, suction flow -IQ, discharge line pressure A, the impeller blade angle α of the pump, and the impeller rotation speed N, which are fluid fluctuation factors, These detected values are input to the arithmetic processing unit 11 online 15.

Then, the vibration level L (a) when there is no abnormality in the pump 1 itself corresponding to the detected value is extracted from the storage unit 12 in the arithmetic processing unit 11, and the vibration level L which is this reference value is extracted.
The binary value is compared with the vibration level Llfii, which is the actual measurement value. And L,>L.

In the case of , that is, when the actually measured vibration level 1 value is larger than the vibration level 2 value which is the reference value extracted from the storage device 11, this vibration level L, which is larger than the critical vibration level Lc, is similarly Pon 1 under the operating conditions of
The vibration level is higher than the vibration level L2 in the case where there is no abnormality in the pump 1 itself, and it is determined that the vibration level is caused by an abnormality in the pump 1 itself.

If Ll > L2, this vibration is larger than the critical vibration level Lc, but it is not due to an abnormality in the pump 1 itself, but because the state quantity of the fluid fluctuation factor that causes vibration in the pump 1 is not appropriate. It is determined that this occurred in That is, in this case, it is determined that the operating conditions of the pump 1 are not appropriate, and the pump 1 itself is determined to be normal.

Therefore, if the above-described abnormality diagnosis method for the pump 1 is used, when vibration occurs in the pump 1 during operation, it is possible to determine whether the vibration is caused by an abnormality in the pump 1 itself or by the operating conditions of the pump 1. You can immediately determine whether the problem is caused by the problem.

In the present embodiment, the centrifugal pump 1 has been described as a turbo fluid device, but the invention is not limited to this, and it can also be used as a centrifugal compressor, a radial turbine, or an axial flow pressure unit.

It goes without saying that the present invention is applicable to all turbo fluid devices such as axial flow turbines.

[Effects of the Invention] As explained above, according to the present invention, the following excellent effects can be exhibited.

When diagnosing abnormalities in turbo fluid equipment using vibration detection, it is possible to accurately diagnose abnormalities by immediately determining whether the vibration is caused by an abnormality in the equipment itself or the operating conditions. be able to.

[Brief explanation of drawings]

FIG. 1 is a flow chart showing a method for diagnosing an abnormality in a centrifugal pump according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of the system for diagnosing an abnormality in a centrifugal pump. In the figure, 1 is a centrifugal pump that is a turbo fluid device, 2 is a vibration acceleration sensor that detects the vibration level of the pump, 3, 4
, 6, 7, 8, and 10 are sensors that measure the states of fluctuation factors; 12 is a storage unit that stores vibration level data; and 11 is an arithmetic processing unit that determines equipment abnormality.

Claims (1)

[Claims] 1. Store vibration level data for each fluid fluctuation factor that causes vibration in turbo fluid equipment, detect the vibration level of the equipment during operation, and when this detected value exceeds the set level. The turbo-type fluid is characterized in that the state of the fluctuation factor is measured, the corresponding vibration level data is extracted, and when the detected value is larger than the data value, it is determined that the device is abnormal. Equipment abnormality diagnosis method.