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Date submitted2022-09-30
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Date accepted2023-02-13
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Date published2024-02-29
Improving the efficiency of oil vapor recovery units in the commodity transport operations at oil terminals
- Authors:
- Vladimir V. Pshenin
- Gulnur S. Zakirova
In this paper the problem of losses from evaporation of light fractions of hydrocarbons during loading operations of tanker fleets vessels is considered. It was found that there is no unified approach to modeling the system “tanker – gas phase pipeline – vapor recovery units” in open sources. The absence of a generally recognized model makes it impossible to scientifically justify the application of instruments to reducing losses and the development of corresponding measures. In work it is showed that the dynamics of growth of pressure in the inner tanker capacity is described by a differential equation, considering for non-stationary essence of the process. This equation is converted to a non-dimensional form and investigated in relation to the similarity criteria of this system. This research has allowed to establish unambiguously the general character of pressure changes in the inner tanker capacity, and to predict the peak values of its growth at the initial stage of the loading operation. The obtained equations were tested on real tanker loading data and showed satisfactory convergence with the experimental data. At different stages of the loading opera-tion the component composition of vapor changes, which is shown by chromatographic analysis of the gas mixture. With the availability of a model of hydrocarbon vapor displacement from the inner of tanker, it is possible to propose measures to minimize the negative impact on the environment and return valuable vapors of the product to the technological chain of transportation.
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Date submitted2022-10-13
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Date accepted2022-12-13
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Date published2023-07-19
A complex model of a drilling rig rotor with adjustable electric drive
A modified mathematical model of an asynchronous electric drive of the rotor – a drill string – a bit – a rock is considered and implemented, which develops and generalizes the results of previously performed studies. The model includes the following subsystems: a model of an asynchronous drive with vector control; a model of formation of the resistance moment at the bottom of the bit, taking into account the peculiarities of the interaction between the bit and the rock; a model of a multi-mass mechanical part that takes into account the deformation of the drill string; subsystem for the drilling rig energy-technological parameters formation. The integrated model makes it possible to calculate and evaluate the selected drilling modes, taking into account their electro-mechanical, energy and technological efficiency and the dynamics of drilling processes. The performed computer simulation of drilling modes confirmed the possibility of a stick-slip effect accompanied by high-frequency vibrations during bit stops, which may change the direction of rotation of the bit, its accelerated wear and unscrewing of the drilling tool. Long bit stops lead to a significant decrease in the average bit rotation speed, which can explain the decrease in the ROP and increase in energy consumption when drilling in the zone of unstable bit rotation. The model can be used as a base for further improvement of rotary drilling control systems.
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Date submitted2021-03-05
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Date accepted2021-10-18
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Date published2021-12-16
Physical and mathematical model of rock destruction by a milling machine cutter
As a result of the analysis of the work on rock destruction by cutters of milling of machines, it was found that the existing developments do not allow us to proceed to the derivation of calculation d dependencies for determining fracture resistance, or can be used only in preliminary calculations of the known by design parameters of milling machines. To eliminate these disadvantages, a combined physical and mathematical model of the process of interaction of a single milling cutter with a spherical tip with the rock has been developed. Consideration of the physical picture of the action of forces and stresses acting from the cutter with spherical tips on the separating rock element in the limiting condition allowed to describe analytically the components of total resistance, which are the mathematical part of the physical and mathematical model of rock destruction by cutters. Analytical dependences for determining the tangential and normal components of fracture resistance of rocks of medium hardness have been obtained. The adequacy of the physical and mathematical model to the physical process of destruction of rocks of different hardness by cutters on a universal stand was tested both in the field and in the laboratory conditions. Technical evaluation of the results of experimental studies confirms the reliability of the developed physical and mathematical model.
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Date submitted2020-05-21
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Date accepted2020-10-05
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Date published2020-11-24
Method of calculating pneumatic compensators for plunger pumps with submersible drive
- Authors:
- Eduard O. Timashev
One of the most promising ways to improve the efficiency of mechanized oil production is a plunger pump with a submersible drive, which allows obtaining harmonic reciprocating movement of the plunger. In the pumping process of well products by plunger pumps, oscillations in the velocity and pressure of the liquid in the lifting pipes occur, which lead to an increase in cyclic variable loads on the plunger, a decrease in the drive life period and the efficiency of the pumping unit. To eliminate the pulsation characteristics of the plunger pump and increase the reliability indicators of the pumping unit (in particular, the overhaul period), pneumatic compensators can be used. A method for calculating the optimal technological parameters of a system of deep pneumatic compensators for plunger pumping units with a submersible drive, based on mathematical modeling of hydrodynamic processes in pipes, has been developed. Calculations of the forming flow velocity and pressure in the lifting pipes of submersible plunger units equipped with pneumatic compensators (PC) have been carried out. Influence of the PC technological parameters on the efficiency of smoothing the oscillations of velocity and pressure in the pipes has been analyzed. Non-linear influence of the charging pressure and PC total volume on the efficiency of their work has been established. Optimal pressure of PC charging, corresponding to the minimum pressure in the tubing during the pumping cycle for the considered section of the tubing, is substantiated. Two ultimate options of PC system placement along the lifting pipes are considered. In the first option, PC are placed sequentially directly at the outlet of the plunger pump, in the second - evenly along the lift. It is shown that the first option provides the minimum amplitude of pressure oscillations at the lower end of the tubing and, accordingly, variable loads on the pump plunger. Nature of the pressure and flow velocity oscillations in the tubing at the wellhead for both options of PC placement has similar values .
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Date submitted2017-08-30
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Date accepted2017-11-21
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Date published2018-02-22
Simulation of operation of pneumatic compensator with quasi-zero stiffness in the electric centrifugal submersible pump unit
- Authors:
- A. N. Zotov
- K. R. Urazakov
- E. B. Dumler
The ECSPU pneumatic compensators with quasi-zero stiffness are proposed. The pneumatic compensator with quasi-zero stiffness is suggested to be made in the form of pneumatic spring assemblies having a power characteristic with a positive stiffness working area and a set of successively connected Belleville springs and a power characteristic with a working area of negative stiffness. Structurally, a set of Belleville springs is located inside the air spring and supports pneumatic compensator piston. As a result of adding the negative stiffness of the disc spring washers set and the positive stiffness of the pneumatic spring, the resulting system (the proposed pneumatic compensator) acquires a quasi-zero or specified low stiffness. The efficiency of the suggested pneumatic compensator was determined by the possibility of moving its piston from the effects of various pressure drops. It was assumed that the greater the distance the piston can move under a given action, the more effective the pneumatic compensator is. The effect of various forces acting on the piston in the case of pressure drops on the discharge line of the electric centrifugal submersible pump units (ECSPU) is simulated: a rapidly decreasing load; a sudden increase in the force acting on the piston and vibration impact. In all the considered examples, the displacement of the piston was several meters, which corresponds to the length of the working area of the power characteristic of the considered pneumatic compensator with quasi-zero stiffness. It is shown that existing pneumatic compensators, which are like gas caps, are in principle unable to provide the same displacement of the piston under the same effects on it. For their effective operation, the size of the gas cap should be several tens of meters, which is impossible in the conditions of the well. In the calculations, it is shown that it is possible to manufacture the necessary disk spring washers from various materials: steel; fiberglass FGM; beryllium bronze. Of particular interest are disk spring washers made of beryllium bronze, which are capable of withstanding up to 20 billion load cycles.
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Date submitted1953-07-24
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Date accepted1953-09-01
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Date published1954-12-04
Гидроэлектропривод насосных установок угольных шахт
- Authors:
- Unknown
В условиях угольных шахт регулирование центробежных насосов или вообще не применяется, или осуществляется задвижкой, что приводит к ухудшению к.п.д. насосной установки и, следовательно, к перерасходу энергии на водоотлив. Как показывают данные обследования ряда шахт, номинальный напор установленных насосов часто значительно превосходит напор, необходимый для преодоления статических и динамических сопротивлений при номинальной производительности насосной установки. Это, в свою очередь, во избежание недопустимой перегрузки приводного двигателя, приводит к необходимости продолжительной работы насосов с прикрытой задвижкой, т. е. со значительными непроизводительными потерями. Согласно данным А. И. Веселова, манометрический номинальный напор установленных насосов часто значительно превосходит напор, необходимый для преодоления геодезической высоты нагнетания, а производительность насосов оказывается выбранной с большим запасом. Касаясь, например, шахт Кизеловского района, А. И. Веселов пишет: «Крупнейшие водоотливные установки шахт им. В. И. Ленина и М. М. Володарского работают с излишним запасом напора, а отсюда, естественно, невысокий к. п. д. агрегата. Шахта им. В. И. Ленина на основных насосных станциях имеет излишнюю установленную производительность насосов, которая равна почти пятикратному нормальному притоку».
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Date submitted1951-07-12
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Date accepted1951-09-03
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Date published1952-12-23
Электрическая схема подъемной установки с асинхронным приводом
- Authors:
- Unknown
Для правильного функционирования подъемной установки прежде всего должно быть обеспечено исправное действие смазки главных подшипников, осуществляемой при помощи двух маслонасосов, из которых один рабочий, а другой запасной. Управление маслонасосами производится при помощи переключателя маслонасосов. После замыкания цепи катушки 1РП замкнется ее контакт 1РП и тем самым перекроет разомкнутый при рабочих положениях командо-контроллера контакт КК-0, обеспечивая замыкание цепи катушки 1РП до тех пор, пока эта цепь не будет разорвана конечным выключателем ЗВК, размыкаемым при окончании подъема соответственной клетью. При замкнутой цепи катушки реле 1РП окажется замкнутым контакт этого реле 1РП, находящийся в цепи катушек реверсивных контакторов В и И. В результате этого в данном месте получится замыкание цепи катушек указанных реверсивных контакторов.
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Date submitted1950-07-05
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Date accepted1950-09-18
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Date published1951-04-30
Coefficient of output of transport installations
- Authors:
- N. V. Filatov
The efficiency of mechanical installations is assessed by various indicators. A very important one is the efficiency (efficiency), which characterizes the perfection of mechanisms. The practical significance of this indicator is great. The efficiency gives a certain direction to mechanical engineering and establishes optimal operating modes for the operation of machines. It makes it possible to judge the advantage of a combination of mechanisms and significantly simplifies calculation and design work. For example, based on the efficiency values, in many cases friction bearings were replaced by rolling bearings, steam and heat engines by electric motors, the operation of fans is accepted in accordance with the highest values of its efficiency, etc. In the general theory of machines, the mechanical efficiency is determined by the ratio of the absolute values of the work of useful resistances to the work of all driving forces calculated for the period of steady-state motion. Thus, finding the efficiency is connected, firstly, with the clarification of what to call the work of the forces of useful resistance, and, secondly, with the consideration of the work produced only during movement at a constant speed.
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Date submitted1908-06-28
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Date accepted1908-08-12
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Date published1908-12-01
Illustration of crystal structure with vector circles
- Authors:
- Ye. S. Fedorov
In the article “Precise imagery of space points on a plane”, the problem of such an image in three different elements is solved: vectorial and ordinary circles, and in parallel vectors. The practical application of images in parallel vectors of a system of mines is also given there. I will now show an essential application of the theory to the representation by vectorial circles of the spatial lattices of each structurally studied crystal.