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Date submitted2023-03-16
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Date accepted2023-06-20
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Date published2023-07-19
Evaluation of the influence of the hydraulic fluid temperature on power loss of the mining hydraulic excavator
In the steady state of operation, the temperature of a mining excavator hydraulic fluid is determined by the ambient temperature, hydraulic system design, and power losses. The amount of the hydraulic system power loss depends on the hydraulic fluid physical and thermodynamic properties and the degree of wear of the mining excavator hydraulic system working elements. The main causes of power losses are pressure losses in pipelines, valves and fittings, and leaks in pumps and hydraulic motors. With an increase in the temperature of hydraulic fluid, its viscosity decreases, which leads, on the one hand, to a decrease in power losses due to pressure losses in pipelines, valves and fittings, and, on the other hand, to an increase in volumetric leaks and associated power losses. To numerically determine the level of power losses occurring in the hydraulic system on an example of the Komatsu PC750-7 mining excavator when using Shell Tellus S2 V 22, 32, 46, 68 hydraulic oils with the corresponding kinematic viscosity of 22, 32, 46, 68 cSt at 40 °C, the developed calculation technique and software algorithm in the MatLab Simulink environment was used. The power loss coefficient, obtained by comparing power losses at the optimum temperature for a given hydraulic system in the conditions under consideration with the actual ones is proposed. The use of the coefficient will make it possible to reasonably select hydraulic fluids and set the values of the main pumps limit state and other hydraulic system elements, and evaluate the actual energy efficiency of the mining hydraulic excavator. Calculations have shown that the implementation of measures that ensure operation in the interval with a deviation of 10 % from the optimal temperature value for these conditions makes it possible to reduce energy losses from 3 to 12 %.
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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 submitted2022-04-05
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Date accepted2022-07-21
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Date published2022-11-10
Development of resource-saving technology for excavation of flat-lying coal seams with tight roof rocks (on the example of the Quang Ninh coal basin mines)
- Authors:
- Vladimir P. Zubov
- Le Quang Phuc
It is shown that the creation of the variants of resource-saving systems for the development of long-column mining is one of the main directions for improving the technological schemes for mining operations in the mines of the Kuang Nin coal basin. They provide a reduction in coal losses in the inter-column pillars and the cost of maintaining preliminary workings fixed with anchorage. The implementation of these directions is difficult (and in some cases practically impossible) when tight rocks are lying over the coal seam, prone to significant hovering in the developed space. In the Quang Ninh basin, 9-10 % of the workings are anchored, the operational losses of coal reach 30 % or more; up to 50 % of the workings are re-anchored annually. It is concluded that the real conditions for reducing coal losses and the effective use of anchor support as the main support of reusable preliminary workings are created when implementing the idea put forward at the St. Petersburg Mining University: leaving the coal pillar of increased width between the reused mine working and the developed space and its subsequent development on the same line with the stoping face simultaneously with the reclamation of the reused mine working.
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Date submitted2021-02-28
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Date accepted2021-11-30
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Date published2021-12-27
Substantiation of analytical dependences for hydraulic calculation of high-viscosity oil transportation
- Authors:
- Alexander K. Nikolaev
- Natalia А. Zaripova
One of the development priorities in oil and gas industry is to maintain gas and oil pipeline networks and develop pipeline-connected gas and oil fields of the Arctic zone of the Russian Federation, a promising region the resource potential of which will not only meet a significant portion of internal and external demand for various types of raw materials and primary energy carriers, but will also bring great economic benefits to subsoil users and the state. The mineral and raw material centers of the Nadym-Purskiy and Pur-Tazovskskiy oil and gas bearing areas are among the most attractive regions of the Arctic zone. It is necessary to develop a scientifically substantiated approach to improve the methods of oil transportation from the field to the existing pipelines. As it is known, the task of increasing the efficiency of pipeline transportation of high-viscosity oil is inseparably connected with solving problems in the field of thermal and hydraulic calculation of pipeline system. The article presents the substantiation of dependencies for hydraulic calculation of pipelines transporting high-viscosity oil exhibiting complex rheological properties. Based on the laws of hydraulics for non-Newtonian fluids, the formulas for calculating head losses for fluids obeying Ostwald's law are proposed, their relationship to the classical equations of hydraulics is shown. The theoretical substantiation of looping installation for increasing the efficiency of pipeline transportation of high-viscosity oil taking into account the received dependences for power fluid is considered.
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Date submitted2020-02-19
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Date accepted2020-04-17
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Date published2020-10-08
Decrease in coal losses during mining of contiguous seams in the near-bottom part at Vorkuta deposit
- Authors:
- Oleg I. Kazanin
- Valeriy V. Yaroshenko
The problem of formation of extended zones with high rock pressure (HRP) from safety pillars at the boundaries of extraction pillars formed due to the mine layout of complex geometry is considered at the example of JSC Vorkutaugol mines. A detailed analysis of the remaining reserves of the near-bottom part of the deposit was carried out to estimate losses and the impact of HRP zones from the Chetvertyi protective seam to mining operations on the Troinoi upper seam along with the possibilities for the reduction of sizes of HRP zones at the account of expanding the underworked space. Due to research on the near-bottom part of the Vorkuta deposit, within the framework of the accepted layout, a zone at the Komsomolskaya mine and two zones at the Zapolyarnaya-2 mine were singled out, at which losses at the boundaries of the extraction pillars amount up to 13-22 % of the total resources of the mine field. The high volume of losses in these pillars indicates the relevance of research on the priority extraction impact of protective seams on the efficiency and safety of mining operations in the working area of underworked and HRP zones. Based on the analysis of foreign and Russian experience in the pillar cleaning-up at the boundaries of working areas and the methodical guidelines and instructions, a technological scheme was developed that allows increasing the coal mining recovery factor in the near-bottom part of the Vorkuta deposit from 0.75 to 0.9 without fundamental changing of the ventilation and transport networks and also without purchasing any additional mining equipment. The conducted economic calculations confirmed the effectiveness of implementing the new technological scheme for cleaning-up reserves at the boundaries of extraction districts. The economic effect is from 0.079 to1.381 billion rubles of additional profit from coaxial extraction pillars, depending on the mining and geological conditions and the size of the pillars.
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Date submitted2019-03-21
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Date accepted2019-04-30
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Date published2019-08-23
Actual and Forecast Impact Assessment of Earthquakes on the Global Economic System
- Authors:
- T. P. Skufina
- S. V. Baranov
- V. P. Samarina
Problem of strong earthquakes impact on the global economic system is considered. Geoscientists suggest that increase in Earth's seismicity is highly unlikely, but experts in economic geography say that existing facts indicate increase in seismic risk for economic systems. Using the example of an earthquake in the Tahoku region (Japan, 2011), a comprehensive assessment of economic consequences of a strong earthquake is presented as a part of analysis of three blocks of statistical information: 1) macroeconomic indicators of Japan; 2) stock market indicators; 3) industry indicators of the global economy. Results of the assessment pointed to a new feature of strong earthquakes effects in economically developed regions of the world: globalization processes are spreading regional effects of large earthquakes throughout the world economic system. To understand the magnitude of strong earthquakes problem, estimate of world economy loss from a probable earthquake near the United States, similar to Tahoku, is given. It was established that economic losses would be 2.6 times greater: a drop in the global S&P Global 1200 index would be about 15 %. The farther in time this probable earthquake protects from the Tahoku earthquake, the more globalization will increase losses.
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Date submitted2018-05-07
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Date accepted2018-07-06
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Date published2018-10-24
Hydraulic transportation of thickened tailings of iron ore processing at Kachkanarsky GOK based on results of laboratory and pilot tests of hydrotransport system
- Authors:
- V. I. Aleksandrov
- M. A. Vasileva
The object of study is the system of hydrotransport of iron ore processing tailings at JSC «EVRAZ Kachkanarsky GOK». The aim of the work was to determine the parameters of the hydraulic transport of tailings of the iron ore enrichment at weight concentrations of the solid phase from 30 to 70 % and to develop recommendations for the industrial operation of hydraulic transport systems of highly concentrated slurries of the Tailing Facilities of the Kachkanarsky GOK. Laboratory studies of the parameters of hydrotransport of thickened tail pulps were carried out with the development of a calculation method; pilot tests of the hydrotransport system under the conditions of the Tailing Facilities of the Kachkanarsky GOK. It has been established that using polyurethane coatings on the inner surface of the slurry lines significantly (1.75 times) decrease the specific pressure loss on the hydrotransport of thickened fluids. This allows to significantly increase the range of transportation for placing tailings in the distant parts of the storage zone. The introduction of research results is in the project of reconstruction and development of the tailing facility of the TF of the Kachkanarsky GOK for the period 2018-2020. It is proposed to use the results of work in the project of reconstruction of the hydraulic transport system at the TF of the Kachkanarsky GOK by switching to the hydraulic transport of slurries thickened to weight concentrations of 35-40 % in the slurry pipes with an internal polyurethane coating, which will ensure energy saving in the hydraulic transport process.
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Date submitted2017-12-29
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Date accepted2018-03-06
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Date published2018-06-22
Evaluation of signal properties when searching for cavities in soil under concrete slabs by radio detection stations of subsurface investigation
- Authors:
- G. V. Rudianov
- E. I. Krapivskii
- S. M. Danilev
A method of localization of concealed cavities on the basis of studying of the reflected electromagnetic impulses is considered in the paper. An issue of early detecting of concealed cavities in engineering facilities is a critical one due to a significant influence on further serviceability of a structure. Problems of localization of concealed cavities in the soil body under the concrete slabs of hydropower stations were studied; the results of ground radar detecting investigations of the cavities, physical simulation of a cavity as well as a mathematical modeling of a reflected signal are presented. Modern subsurface radar detection provides methods which allow to reliably detect concealed cavities in the soil. However, it is possible only in case of a clear boundary between the adjacent layers that conditions a jump of dielectric permeability. In the result of an abrupt change of dielectric permeability a reflected wave occurred; the existence of subsurface heterogeneity is conditioned by the properties of this wave. Moreover, the greater is the difference between the values of dielectric permeability in the adjacent layers, the larger amplitude the reflected wave will have. If the cavity is at the stage of forming, i.e. it is filled with the soil of reduced density, then there is no clear boundary at the border of the layers which will condition a gradual change of dielectric permeability with depth. In this case an amplitude of a reflected wave will be minimal and a formation signal will be masked out by jamming signals reflected from various heterogeneities. In such case to determine a cavity at the stage of forming seems to be impossible. To determine poor signals an analysis of a phase of a reflected signal may be used; phase alters in compliance with the reflection coefficient change pattern. The article contains information about signals reflected from the heterogeneities and a conclusion regarding a possibility of detecting cavities in the soil on the basis of a method of coherent processing of signals is made.
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Date submitted2016-09-05
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Date accepted2016-10-27
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Date published2017-02-22
Impact of the shape of geological contact on mining losses in the process of near-contact zone development
- Authors:
- G. S. Kurchin
- S. A. Vokhmin
- A. A. Kytmanov
In Russia development of mineral resources is carried out on a truly grand scale, and mining industry is in its essence a basic sector, supporting and facilitating the development of national economy. It predetermines the need of safe and responsible attitude towards riches of our subsoil – mineral resources. With this in mind, one of the key requirements to extraction technologies is minimization of mining losses and ore dilution. The biggest ore losses in the mining block take place in the process of development of contact areas between the ore body and surrounding rocks, due to differences between development pattern and surface of geological contact. Complexity of the contact between ore and surrounding rocks is traditionally characterized by so called «stochastic contact zone». Technological difficulty of extracting ore from the ore – wallrock contact is determined by volatility of geometric parameters in «stochastic contact zone» in the plane of geological contact. Current paper focuses on the issues of standard-setting for mining losses and ore dilution in the process of near-contact zone development. A method is suggested to estimate standard values of losses and ore dilution in stochastic zones. Authors have developed an algorithm of defining the shape of the contact. In the stochastic zone the contact can have a rectangular, sinusoidal, serrate and straight-line shapes. Research has established a relation between the contact shape and amounts of mining losses and ore dilution, formulas to calculate standard values are presented. Using suggested method, standard values for contact ore losses can be obtained in a quicker and more reliable way.
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Date submitted2015-12-01
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Date accepted2016-02-29
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Date published2016-12-23
Simulation of diesel engine energy conversion processes
- Authors:
- A. S. Afanasev
- A. A. Tretyakov
In order to keep diesel engines in good working order the troubleshooting methods shall be improved. For their further improvement by parameters of associated processes a need has arisen to develop a diesel engine troubleshooting method based on time parameters of operating cycle. For such method to be developed a computational experiment involving simulation of diesel engine energy conversion processes has been carried out. The simulation was based on the basic mathematical model of reciprocating internal combustion engines, representing a closed system of equations and relationships. The said model has been supplemented with the engine torque dynamics taking into account the current values of in-cylinder processes with different amounts of fuel injected, including zero feed. The torque values obtained by the in-cylinder pressure conversion does not account for mechanical losses, which is why the base simulation program has been supplemented with calculations for the friction and pumping forces. In order to determine the indicator diagram of idle cylinder a transition to zero fuel feed mode and exclusion of the combustion process from calculation have been provisioned.
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Date submitted2014-12-20
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Date accepted2015-02-13
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Date published2015-12-25
Design procedure of pressure losses for hydrotransport of the high concetration pulps
- Authors:
- V. I. Aleksandrov
- Pavel Vlasak
In the paper it is shown that application of standard design methods for hydrotransport used for slurry with small concentration of a solid phase and for hydrotransport of high concentration slurry leads to considerable divergences between practical values of pressure losses which are received as a result of calculation. A major factor, which defines errors of calculation of hydrotransport of slurry with high concentration of a solid phase by means of standard techniques, is that these techniques do not consider rheological characteristics and parameters substantially influencing the amount of spe-cific pressure losses. The offered model of a pulp movement and technique developed on the basis of this model allow to define hydrotransport parameters with a margin error no more than 0,1.
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Date submitted2009-08-13
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Date accepted2009-10-30
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Date published2010-02-01
Reducing losses ore between whole chamber for the design of lower layers mine by Gubkin of open joint-stock company «Industrial complex KMAruda»
- Authors:
- E. I. Boguslavskiy
- P. V. Korzhavykh
Technological decisions on decrease in losses of ore in between chamber walls are considered at designing of the bottom horizons of mine of Gubkin. It is offered two variants of decrease in losses of the ore technologically compatible with each other for their simultaneous use. Results of calculation of losses of ore and economic consequences are resulted. The basic actions which are necessary for carrying out, before introduction of technological decisions in manufacture are described.
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Date submitted2009-08-04
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Date accepted2009-10-26
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Date published2010-02-01
The strategic analysis of resource conservation technology capabilities for the underground gas storage facilities
- Authors:
- G. S. Elizarova
General estimate the appeal of the resource conservation technologies in combination with growth prospectives, profitability and possible instability in underground gas storage facilities is received.
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Date submitted2009-07-12
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Date accepted2009-09-08
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Date published2010-04-22
Account and movement of reserves in the information system of Silvinit co.
- Authors:
- A. V. Kataev
- S. N. Kutovoi
- E. M. Efimov
- M. V. Gilev
At ore mines of the Silvinit Co. for accounting and movement of reserves are developed and used special tools, using GIS within the information system. Their use allows to automate accounting and monitoring of status and movement of stocks, including the formation of the reporting tables.