DEFINITION OF DIAGNOSTIC SIGNS OF FAULT CONDITION OF CENTRIFUGAL PUMP UNIT IN THE SPECTRUM OF CURRENT OF ELECTRIC MOTOR

2017 ◽  
pp. 50-57
2015 ◽  
pp. 29-33
Author(s):  
V. A. Kopyrin ◽  
V. A. Iordan ◽  
O. V. Smirnov

The authors provide a method for compensation of the reactive power inside a well. In the environment Matlab/ Simylink a model was developed of the site of the electrical centrifugal pump unit power supply from the transformer substation. A comparison is made of the proposed method of downhole reactive power compensation with the existing method.


2019 ◽  
Vol 98 (10) ◽  
pp. 1068-1073
Author(s):  
Oksana I. Shevchenko ◽  
D. V. Rusanova ◽  
O. L. Lakhman

Introduction. Issues of studying the central origins and development of оccupational pathology in the faces of flight personnel define a need for the application of neurophysiological and neuropsychological methods of research. Material and methods. The levels of constant potential (LCP), characteristics the somatosensory caused potentials (SSVP), neuropsychological features in 95 patients with оccupational neurosensory deafness (ONSD) and 35 cases in a group of comparison are studied. Methods of the statistical analysis with a definition of W-of criterion of Shapiro-Uilka, Mann-Whitney›s U-criterion, coefficient of correlation of Spirmen, the discriminant analysis are applied. Results. in ONSD at patients the quantity of cases with the increased values of average LCP were established to prevail significantly in comparison with those in patients of a group of comparison (39% and 13% respectively, р = 0.03), strengthening of neuropower exchange in right and left frontal, central, left central, left parietal, right temporal assignments, increase in duration of the latent period of N18, N30 components are registered (р < 0.05). The condition of the cognitive sphere was characterized by the easily expressed violations of functions of analytical and synthetic thinking, оral-aural memory, visual, long-term memory, reciprocal coordination, impressive speech. Correlation connection between the index of N13-N20 and indices characterizing a condition of long-term memory, reciprocal coordination, the expressional speech is established (rs=0.45; 0.28; 0.28 at р =0.008; 0.04; 0.03 respectively), an index the between hemispheres of the relations Fd-Fs and latency of P25 and N30 (rs = 0.53 and 0.29 at р =0.009; 0.02 respectively). Diagnostic signs of brain deficiency at patients with ONSD were indices of visual gnosis, reciprocal coordination, LCP in right central, central parietal assignments of a brain, duration of the latent period of N30, N18-N20 (F=9.14; 5.43; 6.08; 4.41 4.77; 4.34 respectively). Conclusions. Violations of power metabolism in the frontal and central and parietal and temporal assignments of a brain, a functional condition of the central carrying-out structures, disorganization of cognitive activity were established to be a consequence of the impact of aviation noise and the reason of brain deficiency.


2014 ◽  
Vol 630 ◽  
pp. 383-387
Author(s):  
Alisa Filofteia Oprea ◽  
Nicolae Popa ◽  
Constantin Onescu

The purpose of the pumps safety and failure mechanism used in processing industry is the loss limitation using mechanical face seals. Studying the notified damages analysis, the conclusion shows that in a high percent these were induced by vibrations. The vibration monitoring, as part of a proactive and predictive maintenance program, becomes necessary to reduce the environment pollution and the mechanical face seals damages. Due to the fact that the analyzed system is made of centrifugal pump, coupling, bearings and electric motor, we will use vibrations in the diagnose process.


A stepper motor is a digital device which is like a computer that runs on pulses. It can be directly connected with digital computer unlike D.C. motor for which A/D or D/A converters are needed. In fact, stepper motor is an electric motor which moves or rotates in series of small discrete steps. A stepper motor is an electromechanical device which converts electrical pulses into discrete mechanical movements. In this chapter, the authors discuss the stepper motor. It starts with the definition of stepper motor, its basic function, and principle of working. They then discuss the types and construction of stepper motor. Finally, this chapter concludes with the applications of stepper motor.


2019 ◽  
pp. 38-45
Author(s):  
I. Yu. Bykov ◽  
Z. H. Yagubov ◽  
P. S. Shichev

The article contains the results of a research by definition diagnostic parameters necessary for the development of an electroparametric method for monitoring of the shafts misalignment in centrifugal pumping units. An experimental research was performed using a overhung centrifugal pump unit K 20/30 and measuring equipment. In its turn is determined function of the dependence the relative amplitude of the informative harmonic in the spectrum of the current of the electric motor phase from the parameter of the overall vibration level of a centrifugal pump unit. This function makes it possible to set the values of the diagnostic parameter for the boundaries of the technical state zones of the pump unit, which correspond to the values of the parameter of the general vibration level, in the event of the shafts misalignment. In mathematical modeling of a centrifugal pumping unit, made imitation of mechanical defect on the shaft when changing the value of the relative pump head and operating parameters for multiple units. As a result of modeling were obtained regression equations of the dependencies of the diagnostic parameter on the parameter imitation of defect at different values pump head and for multiple units.


2021 ◽  
Vol 9 (3) ◽  
pp. 274
Author(s):  
Cui Dai ◽  
Yuhang Zhang ◽  
Qi Pan ◽  
Liang Dong ◽  
Houlin Liu

In order to study the vibration mechanism of a marine centrifugal pump unit and explore the contribution of vibration caused by different vibration excitation sources, a marine centrifugal pump with a specific speed of 66.7 was used for research. A numerical calculation model of the flow field and electromagnetic field of the pump unit was established to analyze the frequency spectrum characteristics and contribution of pump unit vibration caused by different excitation sources. Using the modal superposition method, the vibration characteristics of the pump unit caused by fluid excitation and electromagnetic excitation were analyzed. The results show that the main frequency of pump unit vibration caused by fluid excitation was at the 1× blade passing frequency. The main frequency of pump unit vibration caused by electromagnetic excitation was at the 2× utility frequency. The contribution of different excitation sources to the vibration of marine centrifugal pump unit was in the following order: fluid excitation on the inner surface of the pump > electromagnetic excitation > fluid excitation in the impeller.


Sign in / Sign up

Export Citation Format

Share Document