CN112576537B - Real-time evaluation method and evaluation system for centrifugal pump cavitation degree - Google Patents

Real-time evaluation method and evaluation system for centrifugal pump cavitation degree Download PDF

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CN112576537B
CN112576537B CN202011465311.7A CN202011465311A CN112576537B CN 112576537 B CN112576537 B CN 112576537B CN 202011465311 A CN202011465311 A CN 202011465311A CN 112576537 B CN112576537 B CN 112576537B
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centrifugal pump
blade
value
passing frequency
data
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CN112576537A (en
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张翮辉
常春平
游浩林
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Chengwu Herun New Material Technology Co ltd
Hefei Minglong Electronic Technology Co ltd
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Xiangtan University
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
    • F04D27/001—Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
    • G06F17/10—Complex mathematical operations
    • G06F17/14—Fourier, Walsh or analogous domain transformations, e.g. Laplace, Hilbert, Karhunen-Loeve, transforms
    • G06F17/141—Discrete Fourier transforms
    • G06F17/142—Fast Fourier transforms, e.g. using a Cooley-Tukey type algorithm

Abstract

The invention discloses a real-time evaluation method for the cavitation degree of a centrifugal pump, which circularly carries out the following steps at equal time intervals: obtaining blade passing frequency; collecting a vibration acceleration signal at the thinnest part of the wall thickness of a centrifugal pump shell; carrying out fast Fourier transform on the vibration acceleration signal to obtain vibration acceleration amplitudes corresponding to different vibration frequencies; integrating to obtain a left interval integral value of the passing frequency of the blade, a right interval integral value of the passing frequency of the blade and a left interval integral value of the passing frequency of the blade; calculating to obtain a left interval integral relative value of the passing frequency of the blade and a right interval integral relative value of the passing frequency of the blade; and calculating to obtain a cavitation degree value of the centrifugal pump. The invention also discloses a real-time evaluation system of the cavitation degree of the centrifugal pump, which comprises a data input module, a data acquisition module, a data storage module, a data operation module and a data display module. The real-time evaluation method and the real-time evaluation system for the cavitation degree of the centrifugal pump are low in cost, stable, reliable and wide in applicability.

Description

Real-time evaluation method and evaluation system for centrifugal pump cavitation degree
Technical Field
The invention relates to the field of centrifugal pumps, in particular to a real-time evaluation method and an evaluation system for the cavitation degree of a centrifugal pump.
Background
As a typical general machine, the centrifugal pump is widely used in various fields of industrial and agricultural production and resident life, plays an irreplaceable role in fluid conveying and pressurization, and therefore, the centrifugal pump has a very important significance on a fluid system where the centrifugal pump can safely and stably operate. In the working process of the centrifugal pump, cavitation is a harmful phenomenon with great harm, and has great negative influence on the safety degree and performance of the centrifugal pump. Cavitation is an abnormal condition caused by the fact that the pressure near a certain position of the inlet of a centrifugal pump impeller blade is reduced to the saturated vapor pressure of the conveyed liquid at the temperature. Under the operating condition, local liquid is subjected to phase change boiling, generated steam bubbles are collapsed and condensed back to a liquid state due to the fact that pressure is rapidly increased when the steam bubbles flow along with the liquid from an inlet to the periphery, the liquid is enabled to rush from the periphery to the center of the bubbles at a high speed through the process, and impact with high frequency and high instantaneous pressure is generated. Therefore, from the perspective of safe and stable operation of the centrifugal pump, it is necessary to monitor and evaluate whether the centrifugal pump is subjected to cavitation and the severity of the cavitation in real time, so that the operation and maintenance personnel of the centrifugal pump can grasp the operation state of the centrifugal pump in time and take intervention and preventive measures quickly when necessary to avoid adverse consequences.
Since the centrifugal pump cavitation is accompanied by the change of the internal fluid pressure and the reduction of the lift, the cavitation degree of the centrifugal pump is usually determined by monitoring the change of the internal pressure or the lift of the centrifugal pump in the known technical scheme. However, considering that the change of the internal pressure or the lift of the centrifugal pump is closely related to the flow passing through the centrifugal pump, the technical means for judging the cavitation degree of the centrifugal pump by monitoring the change of the internal pressure or the lift of the centrifugal pump not only depends on expensive instruments such as a precise pressure sensor, but also needs to accurately master the change rule of the internal pressure and the lift of the centrifugal pump along with the flow under the non-cavitation working condition in the actual application process, thereby causing great inconvenience in application and being not beneficial to large-scale popularization and use. Research shows that because of the dynamic and static interference effect between the impeller and the partition tongue in the process of fluid flowing inside the centrifugal pump, the fluid pulsation phenomenon which takes the passing frequency of the blades as the main component exists inside the centrifugal pump, which causes the vibration of the centrifugal pump shell under the corresponding frequency; in the cavitation working condition, due to the fact that bubbles are continuously generated and broken near the impeller, the separation effect of fluid pulsation energy is brought, and the centrifugal pump shell is subjected to fluid pulsation impact which is slightly lower than the passing frequency of the blades and slightly higher than the passing frequency of the blades besides vibration with the passing frequency of the blades being the main frequency. The scientific discovery brings a new approach to the evaluation technology of the centrifugal pump cavitation.
Due to the complexity of the field service environment of the centrifugal pump and the uncertainty of the operation condition, in the currently known technical scheme, a low-cost and high-reliability technical means is not used for accurately evaluating the cavitation degree in the operation process of the centrifugal pump, but the evaluation depends on the experience accumulation and subjective judgment of a complex and expensive instrument system and field operators. Therefore, it is a technical problem to be solved urgently how to design a real-time evaluation method for evaluating the cavitation degree of the centrifugal pump, which is controllable in cost, objective, scientific, stable, reliable and wide in application range, and develop a corresponding evaluation system, aiming at the defects of the conventional evaluation means for the cavitation degree of the centrifugal pump.
Disclosure of Invention
In order to solve the technical problems, the invention provides a real-time evaluation method of the centrifugal pump cavitation degree, which has controllable cost, objectivity, scientificity, stability, reliability and wide application range, and provides a real-time evaluation system of the centrifugal pump cavitation degree.
The technical scheme for solving the problems is as follows: a real-time evaluation method for the cavitation degree of a centrifugal pump is characterized in that the following steps are sequentially and circularly carried out according to a certain time interval:
step 1, determining the rated rotating speed n of the centrifugal pump and the number Z of blades of the impeller, and calculating to obtain the passing frequency F of the blades:
F＝nZ/60 (1)
wherein F is the passing frequency of the blade, Hz; n is the rated rotation speed of the centrifugal pump, r/min; and Z is the number of blades of the centrifugal pump impeller.
And 2, acquiring a vibration acceleration signal at the thinnest part of the wall thickness of the centrifugal pump shell according to a fixed sampling frequency.
And 3, performing fast Fourier transform on the vibration acceleration signal to obtain vibration acceleration amplitude A corresponding to different vibration frequencies f.
Step 4, sequentially integrating the vibration acceleration amplitude A in three different vibration frequency intervals of (1-p-q) F not more than F not more than (1-p + q) F, (1-g) F not more than F not more than (1+ g) F and (1+ p-q) F not more than F not more than (1+ p + q) F, and obtaining a blade passing frequency left interval integral value IALIntegral value IA of blade passing frequency interval0And blade passing frequency right interval integral value IAR：
Figure BDA0002833921590000021
Figure BDA0002833921590000022
Figure BDA0002833921590000023
In the formulas (2) to (4), the value of p is 0.07-0.1, q is equal to g, and the value of q and g is 0.03-0.05.
Step 5, integrating value IA of blade passing frequency interval0Respectively calculating and obtaining a left interval integral relative value K of the passing frequency of the blade as a referenceLIntegral relative value K of right interval of passing frequency of bladeR：
KL＝IAL/IA0 (5)
KR＝IAR/IA0 (6)
K in the formulae (5) and (6)LAnd KRThe left interval integral relative value of the passing frequency of the blade, the right interval integral relative value of the passing frequency of the blade, IAL、IA0And IARThe left interval integral value, the right interval integral value and the left interval integral value of the blade passing frequency obtained in the step 4 are respectively obtained.
Step 6, calculating the left interval integral relative value K of the blade passing frequency obtained in the step 5LIntegral relative value K of right interval of passing frequency of bladeRObtaining a cavitation degree value C of the centrifugal pump:
if it is
Figure BDA0002833921590000031
Or
Figure BDA0002833921590000032
The cavitation degree value C of the centrifugal pump is 0;
if it is
Figure BDA0002833921590000033
The centrifugal pump cavitation degree value C is calculated by the following formula:
Figure BDA0002833921590000034
in the formula (7), K is the left interval integral relative value K of the blade passing frequencyLIntegral relative value K of right interval of passing frequency of bladeRSum, b1Is between 0.25 and 0.35, b2The value of (a) is between 0.8 and 1.2.
The certain time interval is a fixed time interval between 1 minute and 30 minutes.
In the method for evaluating the cavitation degree of the centrifugal pump in real time, the fixed sampling frequency in the step 2 is a frequency value between 3 times of the blade passing frequency F and 10 times of the blade passing frequency F.
A real-time evaluation system for the cavitation degree of a centrifugal pump for implementing the real-time evaluation method, characterized in that: the device comprises a data input module, a data acquisition module, a data storage module, a data operation module and a data display module:
the data input module, the data acquisition module, the data operation module and the data display module are all connected with the data storage module;
the data input module is used for manually inputting the value of the passing frequency F of the centrifugal pump blade;
the data acquisition module is used for acquiring a vibration acceleration signal at the thinnest part of the wall thickness of the centrifugal pump shell in real time at a fixed sampling frequency according to a certain time interval;
the data storage module stores the data provided by the data input module, the data acquisition module and the data operation module and provides the cavitation degree value C of the centrifugal pump to the data display module;
the data display module is used for displaying the evaluation result of the cavitation erosion degree value C of the centrifugal pump in real time;
the data operation module obtains the value of the passing frequency F of the centrifugal pump blade input by the data input module and the vibration acceleration signal of the thinnest part of the wall thickness of the centrifugal pump shell, which is acquired by the data acquisition module, through the data storage module, processes and operates related data, and finally outputs the calculated cavitation degree C of the centrifugal pump to the storage module.
The invention has the beneficial effects that:
1. aiming at the actual conditions that the service environment of the centrifugal pump is complex and the flow working condition is full of uncertainty, the method has the advantages that the fluid pulsation component slightly deviating from the passing frequency of the blade is increased when the cavitation working condition of the centrifugal pump is grasped, the vibration acceleration signal at the thinnest part of the wall thickness of the shell of the centrifugal pump is collected and corresponding data analysis is carried out to judge the cavitation degree, the method gives full play to the advantages of data analysis, not only can the real-time evaluation of the cavitation degree of the centrifugal pump be accurately realized, but also the method has the outstanding advantages of low cost, stable operation and the like.
2. The method collects the vibration acceleration signal at the thinnest part of the wall thickness, and the method is helpful for extracting the characteristic component of the signal when cavitation occurs. By adopting the fast Fourier transform and the cavitation degree evaluation function, the signal analysis technology and the fuzzy mathematical principle are organically combined for the mode identification of the cavitation degree of the centrifugal pump, and the method has the advantage of objective science; meanwhile, in the process of judging the cavitation degree of the centrifugal pump, the relative magnitude between the integral value of the left interval of the passing frequency of the blade and the integral value of the right interval of the passing frequency of the blade is compared at first, and the cavitation degree of the centrifugal pump is evaluated only when the difference between the integral value of the left interval of the passing frequency of the blade and the integral value of the right interval of the passing frequency of the blade is not large, so that interference factors can be effectively avoided, and misdiagnosis is avoided.
3. The real-time evaluation method for the cavitation degree of the centrifugal pump provided by the invention is objective, scientific and wide in application range, and the corresponding evaluation system has controllable hardware cost, stable operation and easy realization.
Drawings
FIG. 1 is a flow chart of a method for real-time evaluation of the degree of cavitation of a centrifugal pump according to the present invention.
Fig. 2 is a block diagram of a real-time evaluation system of the cavitation degree of the centrifugal pump according to the present invention.
Fig. 3 is a graph of vibration acceleration amplitude a corresponding to different vibration frequencies f in an application example of the present invention.
Detailed Description
The invention is further described below with reference to the figures and examples.
As shown in fig. 1, a real-time evaluation method of the cavitation degree of a centrifugal pump is characterized in that the following steps are sequentially and cyclically carried out according to a fixed time interval between 1 minute and 30 minutes:
step 1, determining the rated rotating speed n of the centrifugal pump and the number Z of blades of the impeller, and calculating to obtain the passing frequency F of the blades:
F＝nZ/60 (1)
wherein F is the passing frequency of the blade, Hz; n is the rated rotation speed of the centrifugal pump, r/min; and Z is the number of blades of the centrifugal pump impeller.
And 2, acquiring a vibration acceleration signal at the thinnest part of the wall thickness of the centrifugal pump shell according to a fixed sampling frequency.
The fixed sampling frequency is a frequency value between 3 times the blade passing frequency F and 10 times the blade passing frequency F.
And 3, performing fast Fourier transform on the vibration acceleration signal to obtain vibration acceleration amplitude A corresponding to different vibration frequencies f.
Step 4, sequentially integrating the vibration acceleration amplitude A in three different vibration frequency intervals of (1-p-q) F not more than F not more than (1-p + q) F, (1-g) F not more than F not more than (1+ g) F and (1+ p-q) F not more than F not more than (1+ p + q) F, and obtaining a blade passing frequency left interval integral value IALIntegral value IA of blade passing frequency interval0And blade passing frequency right interval integral value IAR：
Figure BDA0002833921590000051
Figure BDA0002833921590000052
Figure BDA0002833921590000053
In the formulas (2) to (4), the value of p is 0.07-0.1, q is equal to g, and the value of q and g is 0.03-0.05.
Step 5, integrating value IA of blade passing frequency interval0Respectively calculating and obtaining a left interval integral relative value K of the passing frequency of the blade as a referenceLIntegral relative value K of right interval of passing frequency of bladeR：
KL＝IAL/IA0 (5)
KR＝IAR/IA0 (6)
K in the formulae (5) and (6)LAnd KRThe left interval integral relative value of the passing frequency of the blade, the right interval integral relative value of the passing frequency of the blade, IAL、IA0And IARThe left interval integral value, the right interval integral value and the left interval integral value of the blade passing frequency obtained in the step 4 are respectively obtained.
Step 6, calculating the left interval integral relative value K of the blade passing frequency obtained in the step 5LIntegral relative value K of right interval of passing frequency of bladeRObtaining a cavitation degree value C of the centrifugal pump:
if it is
Figure BDA0002833921590000054
Or
Figure BDA0002833921590000055
The cavitation degree value C of the centrifugal pump is 0;
if it is
Figure BDA0002833921590000061
The centrifugal pump cavitation degree value C is calculated by the following formula:
Figure BDA0002833921590000062
in the formula (7), K is the left interval integral relative value K of the blade passing frequencyLIntegral relative value K of right interval of passing frequency of bladeRSum, b1Is between 0.25 and 0.35, b2The value of (a) is between 0.8 and 1.2.
As shown in fig. 2, a real-time evaluation system for centrifugal pump cavitation degree is characterized in that: the device comprises a data input module, a data acquisition module, a data storage module, a data operation module and a data display module:
the data input module, the data acquisition module, the data operation module and the data display module are all connected with the data storage module;
the data input module is used for manually inputting the value of the passing frequency F of the centrifugal pump blade;
the data acquisition module is used for acquiring a vibration acceleration signal at the thinnest part of the wall thickness of the centrifugal pump shell in real time at a fixed sampling frequency according to a certain time interval;
the data storage module stores the data provided by the data input module, the data acquisition module and the data operation module and provides the cavitation degree value C of the centrifugal pump to the data display module;
the data display module is used for displaying the evaluation result of the cavitation erosion degree value C of the centrifugal pump in real time;
the data operation module obtains the value of the passing frequency F of the centrifugal pump blade input by the data input module and the vibration acceleration signal of the thinnest part of the wall thickness of the centrifugal pump shell, which is acquired by the data acquisition module, through the data storage module, processes and operates related data, and finally outputs the calculated cavitation degree C of the centrifugal pump to the storage module.
Examples
Rated flow 1250m for certain centrifugal pump of certain water supply pump station3And h, the rated rotating speed n is 3000r/min, and the blade number Z of the centrifugal pump impeller is 6. The blade passing frequency F-nZ/60-3000-6/60-300 Hz of the centrifugal pump was calculated.
The signal acquisition and the evaluation of the cavitation degree were sequentially performed at regular time intervals of 10 minutes, and the implementation of this example will be described below with reference to a certain 1 time interval as an example.
The vibration acceleration signal at the thinnest part of the wall thickness of the centrifugal pump shell is collected according to the sampling frequency of 1500Hz which is 5 times of the passing frequency F of the blade, the vibration acceleration signal is subjected to fast Fourier transform, the vibration acceleration amplitude A corresponding to different vibration frequencies F is obtained, and the drawing is shown in figure 3. Fig. 3 shows a graph of the vibration acceleration amplitude a for different vibration frequencies f.
Taking p as 0.1 and q as g as 0.05, and sequentially adding p as more than or equal to 255Hz as less than or equal to F as less than or equal to 285Hz (namely 0.85F as less than or equal to F as less than or equal to 0.95F) and adding p as more than or equal to q as less than or equal to g as less than or equal to 0.05, and adding p as more than or equal to 285Hz as less than or equal to F as less than or equal to 315Hz (namely, adding p as less than or equal to 0.1 and q as more than or equal to g as less than or equal to 285HzF is more than or equal to 0.95F and less than or equal to 1.05F) and F is more than or equal to 315Hz and less than or equal to 345Hz (i.e. F is more than or equal to 1.05F and less than or equal to 1.15F) are respectively integrated with the vibration acceleration amplitude A, and the left interval integral value IA of the passing frequency of the blade is obtainedLIntegral value IA of blade passing frequency interval of 9.65024.66 and blade passing frequency right interval integral value IAR9.87. Further calculating to obtain a left interval integral relative value K of the passing frequency of the bladeL＝IAL/IA09.65/24.66 is 0.39, and the blade passing frequency right interval integral relative value KR＝IAR/IA09.87/24.66 is 0.40, and the sum of the two is 0.79.
Due to the fact that
Figure BDA0002833921590000071
Namely have
Figure BDA0002833921590000072
Therefore, the cavitation degree value C of the centrifugal pump is calculated by the following formula:
Figure BDA0002833921590000073
get b1＝0.3，b2When the value is 0.9, then b is1<K<b2Therefore, the cavitation degree value C of the centrifugal pump is calculated as follows:
Figure BDA0002833921590000074
the calculated cavitation degree value C of the centrifugal pump is 0.42, which shows that the current centrifugal pump has obvious cavitation.
And finally, the data operation module transmits the obtained value 0.42 of the cavitation degree value C of the centrifugal pump to the data storage module, and the data storage module transmits the value to the data display module for displaying.
The method and the system for evaluating the cavitation degree of the centrifugal pump in real time provided by the embodiment combine vibration acceleration signal acquisition and data analysis, wherein the data analysis organically combines a signal analysis technology and a fuzzy mathematical principle, and the data analysis effectively grasps the characteristic that the fluid pulsation component slightly deviating from the passing frequency of the blade is increased when the centrifugal pump is under the cavitation working condition, and the fuzzy judgment of the cavitation degree is carried out by acquiring the vibration acceleration signal at the thinnest part of the wall thickness of the centrifugal pump shell and carrying out corresponding data analysis, so that the real-time evaluation of the cavitation degree of the centrifugal pump is more accurately realized, and the method and the system have the outstanding advantages of low cost, stable operation and the like; meanwhile, in the process of judging the cavitation degree of the centrifugal pump, the relative magnitude between the integral value of the left interval of the passing frequency of the blade and the integral value of the right interval of the passing frequency of the blade is compared at first, and the cavitation degree of the centrifugal pump is evaluated only when the difference between the integral value of the left interval of the passing frequency of the blade and the integral value of the right interval of the passing frequency of the blade is not large, so that interference factors can be effectively avoided, and misdiagnosis is avoided. Therefore, in general, the real-time evaluation method for the cavitation degree of the centrifugal pump provided by the embodiment does not depend on long-term experience and subjective judgment of field operation and maintenance personnel, but starts from objective data; the field data acquisition only aims at the vibration signal at the thinnest part of the shell of the centrifugal pump, and the input data only has the blade passing frequency of the centrifugal pump, so the application range is wide; meanwhile, the hardware cost of the corresponding evaluation system is controllable, the operation is stable, and the field deployment is easy.

Claims (4)

1. A real-time evaluation method for the cavitation degree of a centrifugal pump is characterized in that the following steps are sequentially and circularly carried out according to a certain time interval:
step 1, determining the rated rotating speed n of the centrifugal pump and the number Z of blades of the impeller, and calculating to obtain the passing frequency F of the blades:
F＝nZ/60 (1)
wherein F is the passing frequency of the blade, Hz; n is the rated rotation speed of the centrifugal pump, r/min; z is the number of blades of the centrifugal pump impeller;
step 2, collecting a vibration acceleration signal at the thinnest part of the wall thickness of the centrifugal pump shell according to a fixed sampling frequency;
step 3, performing fast Fourier transform on the vibration acceleration signal to obtain vibration acceleration amplitude A corresponding to different vibration frequencies f;
step 4, sequentially integrating the vibration acceleration amplitude A in three different vibration frequency intervals of (1-p-q) F not more than F not more than (1-p + q) F, (1-g) F not more than F not more than (1+ g) F and (1+ p-q) F not more than F not more than (1+ p + q) F, and obtaining a blade passing frequency left interval integral value IALIntegral value IA of blade passing frequency interval0And blade passing frequency right interval integral value IAR：
Figure FDA0003528965450000011
Figure FDA0003528965450000012
Figure FDA0003528965450000013
In the formulas (2) to (4), the value of p is 0.07-0.1, q is equal to g, and the value of q and g is 0.03-0.05;
step 5, integrating value IA of blade passing frequency interval0Respectively calculating and obtaining a left interval integral relative value K of the passing frequency of the blade as a referenceLIntegral relative value K of right interval of passing frequency of bladeR：
KL＝IAL/IA0 (5)
KR＝IAR/IA0 (6)
K in the formulae (5) and (6)LAnd KRThe left interval integral relative value of the passing frequency of the blade, the right interval integral relative value of the passing frequency of the blade, IAL、IA0And IARRespectively obtaining a left blade passing frequency interval integral value, a right blade passing frequency interval integral value and a left blade passing frequency interval integral value obtained in the step 4;
step 6, calculating the left interval integral of the blade passing frequency obtained in the step 5Relative value KLIntegral relative value K of right interval of passing frequency of bladeRObtaining a cavitation degree value C of the centrifugal pump:
if it is
Figure FDA0003528965450000014
Or
Figure FDA0003528965450000015
The cavitation degree value C of the centrifugal pump is 0;
if it is
Figure FDA0003528965450000021
The centrifugal pump cavitation degree value C is calculated by the following formula:
Figure FDA0003528965450000022
in the formula (7), K is the left interval integral relative value K of the blade passing frequencyLIntegral relative value K of right interval of passing frequency of bladeRSum, b1Is between 0.25 and 0.35, b2The value of (a) is between 0.8 and 1.2.
2. The method for real-time assessment of the degree of cavitation in centrifugal pumps according to claim 1, characterized in that said certain time interval is a fixed time interval between 1 minute and 30 minutes.
3. The method for real-time assessment of centrifugal pump cavitation level of claim 1 wherein said fixed sampling frequency of step 2 is a frequency value between 3 times the blade passing frequency F and 10 times the blade passing frequency F.
4. A real-time evaluation system of a cavitation degree of a centrifugal pump for implementing the real-time evaluation method of any one of claims 1 to 3, characterized in that: the device comprises a data input module, a data acquisition module, a data storage module, a data operation module and a data display module:
the data input module, the data acquisition module, the data operation module and the data display module are all connected with the data storage module;
the data input module is used for manually inputting the value of the passing frequency F of the centrifugal pump blade;
the data acquisition module is used for acquiring a vibration acceleration signal at the thinnest part of the wall thickness of the centrifugal pump shell in real time at a fixed sampling frequency according to a certain time interval;
the data storage module stores the data provided by the data input module, the data acquisition module and the data operation module and provides the cavitation degree value C of the centrifugal pump to the data display module;
the data display module is used for displaying the evaluation result of the cavitation erosion degree value C of the centrifugal pump in real time;
the data operation module obtains the value of the passing frequency F of the centrifugal pump blade input by the data input module and the vibration acceleration signal of the thinnest part of the wall thickness of the centrifugal pump shell, which is acquired by the data acquisition module, through the data storage module, processes and operates related data, and finally outputs the calculated cavitation degree C of the centrifugal pump to the storage module.
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