Catastrophe-theory-based Health Condition Evaluation for Centrifugal Pump Unit

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Lixiang Duan ◽  
Dejun Zhang ◽  
Zhuang Yuan
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 ◽  
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.


2017 ◽  
Vol 31 (7) ◽  
pp. 959-973
Author(s):  
Xiuqi Lyu ◽  
Yi Wan ◽  
Jun Takahashi ◽  
Isamu Ohsawa

Carbon fiber–reinforced thermoplastic (CFRTP) composites are gaining popularity in the manufacturing industry of lightweight automobiles. Common composite defects (e.g. voids and delamination) often occur inside CFRTP composites due to their inappropriate manufacturing process and long-term service. In this study, an instrumented tapping system was designed to evaluate the health condition of CFRTP composites by controlling the input force and velocity. The effective mathematical expressions of the contact duration and amplitude of the interactive force were derived to quantify the local stiffness of the tapping area. The amplitude of the interactive force was introduced innovatively as a significant evaluation parameter for a non-closed force–time curve with the time axis due to the influence of constraint condition and coupling effect of the modal shapes excited during tapping. The contact duration of the interactive force over the defective region was longer than that over the sound region. The amplitude of the interactive force applied on the defective area was observed to be lower than that on the sound area. In addition, the applicability and sensitivity of the amplitude of the interactive force was also investigated by changing the dimensions and locations of defects.


2021 ◽  
Vol 9 (4) ◽  
pp. 238-249
Author(s):  
Elena Kulagina

The article consists of two separate publications (Part 1 and Part 2) and analyses social security policy towards people with disability at working age in developed welfare states (social-democratic, conservative-corporatist and neoliberal regimes). Part 2 analyses reform strategies of state assistance programmes for disabled people on the basis of international research as well as statistical data of the EU and OECD for the past 30 years, while considering the changes in the economic climate. The article attends for the funding: expenditures for the programmes (as percentage of GDP and per capita) during periods of economic growth, the 2008–2009 crisis and the following decade. The connection between cyclic economic changes and the number of people with disability is considered. The author examines the combination of approaches to anticrisis management and the dynamics of public spending on programmes for people with disabilities as well as on alternative support schemes and social security in general. The author analyses the level of social protection of people with disability: poverty and inequality data based on research data and self-administered health condition evaluation. The article discusses the factors which mitigate the negative effects of the reforms, contribute to the reduction of social tension or, on the contrary, decrease social security in the long-term perspective.


Author(s):  
S. G. Zubairov ◽  
◽  
R. R. Yakhin ◽  
A. N Zotov ◽  
T. I. Salikhov ◽  
...  

The article describes a way to combat fatigue effects in the details of connecting modules of an electric driven centrifugal pump unit for oil production. A constructive solution for implementing the method in relation to complex downhole conditions in the form of a multifunctional damper using a differential piston to transfer it from the transport position when lowering into the well into the working one is shown. For a full-size damper, experimental studies of its vibration- isolating characteristics have been carried out when used in the form of substrates for supporting arms of elastomers of various densities and compositions. The preferred characteristics of elastomers and their ranking for various frequencies of forced vibrations are determined. Keywords: module, connection parts; electrically driven centrifugal pump unit; electrocentrifugal pumping unit; differential piston; damper; sbstrate; vibration velocity.


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