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Date submitted2021-02-20
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Date accepted2021-10-18
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Date published2021-12-16
Thermal protection implementation of the contact overheadline based on bay controllers of electric transport traction substations in the mining industry
The article presents the principle of thermal protection of the contact overheadlineand substantiates the possibility of practical implementation of this principle for rail electric transport in the mining industry. The algorithm for the implementation of modern digital protection of the contact overhead line as one of the functions of the controller is described. A mathematical model of thermal protection is proposed, which follows from the solution of the heat balance equation. The model takes into account the coefficient of the electrical networktopology, as well as the coefficient of consumption of the current-carrying core of the cable, which determines the reduction in the conducting section from contact erosion and the growth of oxide films. Corrections for air flows are introduced when receiving data from an external anemometer, via telemechanics protocol. The mathematical model was tested by writing a real thermal protection program in the C programming language for the bay controller, based on the circuitry of which is the STM32F407IGT6 microcontroller for the microcontroller unit. Verification tests were carried out on a serial bay controller in 2020. The graphs for comparing the calculated and actual values of temperatures, with different flow rates of the current-carrying conductor of the DC cable, are given. To obtain data, telemechanics protocols IEC 60870-104 and Modbus TCP, PLC Segnetics SMH4 were used.
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Date submitted2021-02-20
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Date accepted2021-05-21
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Date published2021-09-20
Analysis of the screw press mouthpiece parameters for 3D extrusion of peat pieces of tubular type
The results of theoretical and experimental studies on the creation of a screw press composite mouthpiece screw press for 3D-forming of peat pieces of a tubular type in the field for intensifying the process of field drying of material in a complex mechanized pit are presented. The main purpose of the study was to substantiate the geometric and design parameters of the screw press composite mouthpiece of the spread machine for the production of peat-agglomerated products of the tubular type. The parameters of the mouthpiece are selected based on the geometric characteristics of the peat pieces. An increase in moisture loss during drying of peat-agglomerated products is provided by forming a peat piece in the form of a thick-walled pipe made of a peat raw materials composed of low and high decomposition degrees in a ratio of 1:3. Additive production of polymer-fiber peat composites by extrusion allows to produce products with improved mechanical properties in comparison with non-reinforced raw materials. The vertical arrangement of the peat tubular piece on the drying field allows to increase the loading of the field area by 10 %, increase the convective heat supply to the piece and reduce the contact coefficient of the piece with the field by three times in comparison with the peat spreading of the pieces in the form of a horizontal tape. Based on the analysis of the shape and size of the agglomerated products, the design of a screw press composite mouthpiece consisting of two conditional molding zones of various configurations has been developed. The article presents a parametric analysis of the volumetric productivity of a screw press with a composite mouthpiece of a tubular type, the energy intensity of mechanical processing is determined, the degree of mechanical processing of peat raw materials is estimated with the optimization of the screw parameters for the production of agglomerated products of a tubular type.
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Date submitted2019-12-20
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Date accepted2020-09-01
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Date published2020-10-08
Features of the underground storages construction in depleted oil and gas condensate fields
The paper considers the features of the underground storages (US) construction in depleted oil and gas condensate fields (DOGCFs). The requirements for the structure of the formation, corresponding to the parameters of the object for possible US creation are presented. The influence of geological, hydrogeological, mining and technical rock formation conditions on the reliability and tightness of underground storages, including underground gas storages, has been evaluated. The necessary conditions for the US design are analyzed at the example of the Ach-Su oil and gas condensate field, in the presence of a well-explored trap with acceptable parameters for the construction of an underground storage. An important aspect is the geological conditions that meet the criteria for selecting the object: the required structure, the absence of fracturing faults, high reservoir properties of the formation, a sufficient volume of the deposit for the storage. Geological conditions lay the basis for determining the individual characteristics of the US construction technology at each DOGCF. The refined results for the current gas-saturated pore volume and the rate of pressure drop in the formation are presented, which makes it possible to select improved technological indicators in the course of operation of the created US. In order to select the optimal option for the design and construction of the US, the results of economic and geological scenarios analysis were studied concurrently with the capabilities of the technological operation of the object and transport system, which can ensure the maximum daily production of the storage.
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Date submitted2016-11-01
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Date accepted2017-01-20
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Date published2017-04-14
Technology and economics of near-surface geothermal resources exploitation
- Authors:
- E. I. Boguslavskii
- V. V. Fitsak
The paper presents economic justification for applicability of near-surface geothermal installations in Luga region, based on results of techno-economic calculations as well as integrated technical and economic comparison of different prediction scenarios of heat supply, both conventional and using geothermal heat pumps (GHP). Construction costs of a near-surface geothermal system can exceed the costs of central heating by 50-100 %. However, operation and maintenance (O&M) costs of heat production for geothermal systems are 50-70 % lower than for conventional sources of heating. Currently this technology is very important, it is applied in various countries (USA, Germany, Japan, China etc.), and depending on the region both near-surface and deep boreholes are being used. World practice of near-surface geothermal systems application is reviewed in the paper.
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Date submitted2013-07-05
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Date accepted2013-09-23
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Date published2014-03-17
Increase of stability of mine workings in the permafrost zone
- Authors:
- A. F. Galkin
Some experimental results of increase of stability of mine workings are presented in this article. The investigated mine workings are located in the permafrost conditions and the increasing of stability is achieved by insulation. Problems of thermal protection of frozen breeds are considered at high temperatures of air in mine workings.
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Date submitted2009-07-12
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Date accepted2009-09-30
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Date published2010-04-22
Development of geothermal resources – higher efficiency in utilization of the earth’s interior
- Authors:
- E. I. Boguslavsky
Preservation of Russia as the great state, its further development and prosperity, appreciably depends on possibilities to provide its own power needs, and also fuel and electric power export. On this historical period, power resources are the basic trading source of replenishment of the state budget. However, oil resources, at preservation of volumes of its export, are quickly exhausted; natural gas is not boundless too. Coal stocks have essentially decreased with disintegration of the USSR, and the remained demand considerable investments, increase of current expenses and are characterised by decrease in quality of coals. Additional expenses on ecological protection of environment will increase. Search of alternative to the organic fuel, burnt in heating plants, is conducted more than ten years. Use of low-temperature sources of thermal energy of resources is one of general directions in the decision of this problem in the XXI-st century. It proves to be true: certain advantages of geothermal resources, a readiness of scientific bases of their development, world industrial experience and specificity of systems of a heat supply in the country.
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Date submitted2008-11-13
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Date accepted2009-01-01
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Date published2009-12-11
The quality of commodity output – the factor of competitiveness iron-ore branch
- Authors:
- R. V. Korchenkov
The problems of quality improving of commodity output are the most urgent and up-to date questions in the period of intromission of Russian on the world market. The country possesses of significant mineral raw ferrous materials, which are poor quality. In conjunction with it mining-and-processing integrated works must develop and improve the process of production in order to provide the quality of the products conforming to world requirements. The main task of iron-ore branch in Russia is to maintain the competitive ability on the foreign market.