The purpose of the study is to identify industrial facilities that are critically important for the fuel and energy complex in the conditions of joint functioning of industries, taking into account the system effect and existing mechanisms of structural redundancy. To identify critically important facilities of the fuel and energy complex based on its operation models derived as a result of stage-by-stage sectoral and general energy studies, a methodology is proposed. It is based on the identification methods of critically important industry facilities on the principles of assessing vulnerability of critically important infrastructure elements. The presented methodology is characterized by the complex and flexible assessment of the critical importance of sectoral facilities, which is carried out on the basis of scenario options of fuel and ener gyomplex operation. The methodology is supplemented with a formalized representation of a typical general energy optimization model, which unifies the relationship between the territorial-production structure of the sectoral systems modeled in it, its information base with the corresponding technical and economic indicators, and the research problems solved with its help. The assessment of the critical importance of gas industry facilities is given for 80 constituent entities of the Russian Federation. The approbation results of the proposed methodology are given on the example of the identification of the critically important gas industry facilities using a model of fuel and energy complex operation with a detailed scheme of the Unified Gas Supply System of Russia. The approbation has revealed the differences in the priority of critically important facilities of the gas industry and the fuel and energy complex. It has also shown a significant influence of the system effect of the mutually coordinated functioning of industries on the fuel and energy supply of consumers. The results obtained confirm the efficiency of the methodology, prove the possibility of its use for assessing the critical importance of power industry branch facilities. The research scheme implemented in the methodology allows to obtain an adequate state of matters with the fuel and energy supply to consumers under cut-out critically important sectoral facilities.

The purpose of the paper is to study the dependence of dielectric losses of mechanically activated grain crops on example of wheat under heat treatment on temperature and external electric field frequency as well as to examine the effect of particle size of fine grain samples on grain electrophysical characteristics and dielectric losses. Experimental samples of dispersed systems with particle sizes in the range from 50 to 1000 μm are prepared by the method of mechanical activation. The temperature dependence of the dielectric loss angle tangent is measured using the dielectric method over a wide frequency range. The dependence of the dielectric loss angle tangent tgδ of mechanically activated wheat samples with the different degrees of particle dispersion in a wide temperature range from 20°C to 250°C with a heating rate of 0.7 deg/min is studied. It is found out that the external electric field frequency varies in the range from 25 Hz to 106 Hz. Electric capacitance and conductivity are measured using an E7-20 immitance meter and a specially designed measuring cell. Dielectric characteristics are calculated. Experimental data are presented in the form of graphs and diagrams. We have determined the correlation of the tangent of the dielectric loss angle tgδ with the frequency of the external electric field and temperature, which is most characteristic for fine samples. The most finely dispersed samples with a particle size of less than 50 microns are shown to have high electrical activity. Increase in the dielectric permittivity and the tangent of the dielectric loss angle is most noticeable at the frequencies below 100 Hz. The study of dielectric characteristics allows to choose an effective energy-saving drying mode of the crop under study.

The purpose of the study is to conduct experimental studies of oil -water emulsion separation in a rectangular separator in the range of velocities along the device working area from 1.43 to 2.5 m/s. The efficiency of emulsion separation is determined by an experimental method based on measuring the density of a two-phase liquid, provided that the density of each component of the mixture is previously determined. The authors propose to use a device with U-shaped elements to increase its performance when separating oil-water emulsions. The device under study including two rows of U-shaped elements consists of one complete separation stage. The authors have conducted experimental studies of the device with U-shaped elements on the "oil-water" system, during which the efficiency of emulsion separation was evaluated. It was detemined that the proposed device provides the highest efficiency of emulsion separation of 68% when the diameter of the holes intended for the exit of the heavy phase equals to 2.5 mm in the range of emulsion velocities from 1.43 to 2.5 m/s. The conducted experimental studies will allow to use a turbulence model for calculation in the programs like Ansys Fluent or FlowVision, which will most adequately describe the separation process of similar emulsions. The experiments have proved the possibility of obtaining high values of efficiency. Therefore, the correct selection of technological parameters (average flow rate, concentration) and the size of the characteristic elements of the proposed device will allow to specify the design of a rectangular separator, for example, to calculate the number of stages to achieve the required separation efficiency or to determine the size of the separation elements.

The purpose of the work is to develop a methodology for designing a stand-alone power supply system based on photovoltaic (PV) converters for technical security equipment power supply. The object of the study is a PV converter - based stand-alone power supply system. Energy storage units, which are widely used in the designing of power supply systems for power supply of technical security equipment are presented. A methodology for designing a power supply system is used, which takes into account the integral effect of solar insolation, ambient temperature in the range from - 40°C to +50°C, temperature of a PV module and a storage battery; PV module capacity; requirements for independent operation of technical security equipment; electrical characteristics of the solar charge controller (rated open-circuit voltage and rated charge current). To calculate the total solar insolation arriving at the surface of a photovoltaic module, the Kastrov model is used for calculating direct solar radiation; the Berlage model is used for calculating the scattered solar energy and the Berland model is used for calculating insolation in cloudy conditions. The studies of lithium-titanate storage batteries have been carried out in the climate chamber and a corresponding mathematical model has been developed for the temperature-dependent capacity of the battery. To determine solar insolation falling on the tilted surface of the PV module the software has been developed in the C# programming language. The designed PV module-based power supply system provides an independent uninterrupted continuous power supply of equipment under constant consumption of no more than 115.2 Wh per day by technical security equipment. The results of the work can be used in the development of a stand-alone power supply system for power supply of technical security equipment, security and control.

The purpose of the paper is to develop a methodology for multi-criteria selection of the capacity of a group of power plants included in the local power system which use local energy resources and renewable energy sources. To form alternative options for the structure of generating capacities, an approach is proposed. It suggests setting of a number of power levels of the base-load generating plant and power plants using renewable energy sources with subsequent determination of the capacity of the flexing generating plant to cover the remaining part of the load schedule. For multi - criteria comparison of the alternative options of the generating capacity structure, the TOPSIS method is used, which is modified to take into account the uncertainty of the decision-maker's preferences (the modification of the method consists in using fuzzy value functions at the stage of normalizing estimates by criteria). The application of this method is considered on the example of the Okhotsk district of the Khabarovsk territory. The estimated capacity of prospective consumers is 69 MW. Alternative options of the power generation structures include four types of power plants: local coal -fired thermal, solar, wind, and diesel. The multi-criteria comparison of generating capacity structure options is performed using the following criteria: normalized cost of electrical energy, estimation of environmental efficiency, and assessment of public opinion on the consequences of power plant construction. Some of the most promising options for the structure of generating capacities are presented, depending on the values of the weight coefficients of the criteria. If the criterion has the large weight reflecting economic efficiency, the structure with the predominance of thermal power plant energy generation is the best. If the criteria of environmental efficiency and public opinion feature large weight, the best structure is the one with significant generation from a renewable energy source (solar power plant). The coefficients of using the installed capacity of different types of power stations with different structures of generating capacities are determined. It is shown that the proposed methodology provides the obtaining of the options of the generating capacity structure that correspond to expressed preferences, taking into account the uncertainty of the initial information and development scenarios. Promising options for the structure of generating capacities are selected for more detailed further research.

The purpose of the paper is to assess application directions and prospects of Irkutsk region power generating coals for the needs of electric and heat power engineering with regard to the possible export of elect rical energy to the countries of South-East Asia, and use as raw materials for coal chemistry needs. The research is carried out using the methods of system analysis involving analysis and synthesis, formalization and concretization, structuring and restructuring, classification. It is the first time when the category of local power generating coals is distinguished under the analysis of the balance reserves of thermal coals. Their feature is low-quality and remoteness from settlements and transportation lanes. Their resource estimate is also given – 0.54 billion tons. An estimate of the recoverable reserves of local coals is obtained: it is 260 million tons. The potential level of local coal production is calculated. A retrospect of consumption trends of regional thermal coals is given and possible application directions are considered in the long run. It is shown that the most demanded direction is the use of coals for energy needs, mainly at thermal power plants. The calculated volumes of coal consumption of two export TPPs, Mugunskaya and Ishideiskaya, are respectively 11 and 6 million tons. According to the authors' calculations, the percentage of electrical energy generation at coal -fired TPPs depending on its export variant implementation can increase by 1.5 – 2.1 times as compared with the level of 2019. Availability of significant reserves of power generating coals in the region makes them a reliable source of energy resources for the electric and thermal power industry, including the export of electrical energy and a promising raw material for the needs of coal chemistry. Potential capacity of coal mining is estimated at 50-60 million tons per year, including 6.5 million tons of local coals. Production potential of coal significantly exceeds its demand both at present and in the future.

The purpose of the study is to provide an economic justification of the application efficiency of vertical axis wind-driven power plants using the principle of differential blade drag under low natural wind speeds from 1 to 15 m/s. The estimated cost is determined by the resource-index method. Calculations are made in two stages: at the first stage a statement is compiled where the consumption of resources for the design volume of work is determined according to the state unit estimate standards collections; at the second stage a local resource estimate is made, and the resource consumption in natural units is converted to cost estimates (in the prices of 2000 year). Local estimates are made using the GRAND-SMETA software package. All costs of construction materials for the wind turbine and supporting structure were assumed at the commercial cost, which was translated to the budget cost of October 2019 using deflators. The transition indices from the prices of 2000 to the prices of 2019 are applied to the cost of materials and machinery operation (without remuneration of engine-drivers) as well as to the amount of labour remuneration for installers and engine-drivers. The cost of the installation set calculated by the strength at 20 m/s natural speed is 1643.591 thousand rubles. This allowed to determine the cost of 1 kWh, which depends on the service life and the average annual wind speed. At a wind speed of 4 m/s the cost is 7.12 rub/kWh; at a wind speed of 8 m/s it is 2.19 rub/kWh. At wind speeds from 5 m/s to 11 m/s with equal exposure time intervals, the average cost of 1 kWh will be within 3.14 rub/kWh. Conducted studies have confirmed the effective use of the proposed vertical axis wind power plant under conditions of low natural wind speeds in Russia. The installation is proved to be competitive in comparison with the traditional methods of energy generation.

The purpose of the article is to explore the possibilities of powder material compaction by the pressure pulse of an electric explosion of a conductor, establish a functional relationship between the parameters of the pressure pulse and an electrical technological installation for powder material compaction, select the parameters for pulse pressure amplitude and duration adjustment, and specify the design options of the working tool for powder material compaction. Analytical studies have been carried out on the basis of the method of formalized representation of the development of the process of pulse pressure wave formation and propagation where the latter is created by an expanding plasma channel of an electric spark in a transmitting medium initiated by an electric explosion of a wire. The simulation of high-speed de formation of the pipe wall under the action of the pulse pressure is carried out in the MATLAB software package. A scanning electron microscope is used to study the microstructure of the breakage of the compacted material with nanomodifiers. Based on the experimental studies on powder material compaction by the pulse pressure created by the expanding plasma channel of a spark initiated by an electric explosion of a wire when the current pulse f rom an electrotechnological installation is supplied to it, it has been determined that the magnitude and shape of the pressure pulse are most influenced by the parameters of this installation. Based on the obtained model studies, the optimal modes for compaction of nanomodified powders have been selected. The relationship is obtained between the parameters of the pulse pressure (Pm amplitude and pressure wave propagation form) and the electrotechnological installation (voltage, inductance, capacitance). It is proposed to use an acoustic-electric wave model to estimate the pressure that provides high-speed deformation of metal pipes, and to plot a deformation profile of metal pipes used for compaction. Analysis of SEM images of the fractures obtained in compact experiments has showed a high degree of particle compaction with the formation of a solid composite.

Abstract: The goal is to develop an algorithm for implementing the edge quality management system for finishing parts with polymer-abrasive brushes, discussed in part 1. The principle of the system approach is used for a formalized description of the system with the presence of relationships between its constituent subsystems. The article considers the algorithm for designing the technological operation of edge processing in accordance with the optimal control system described in part 1. The initial data were: parameters of the workpiece, requirements for roughness and edge parameters, characteristics of tools and equipment. Based on the analysis of the functional capabilities of the operation, an algorithm for selecting the optimal tool among competing ones is obtained, taking into account the technological capabilities of the operation. Based on the developed mathematical models (formation of a rounded edge in size, shape and roughness, cutting force, temperature in the processing zone, tool wear), the optimization of technological parameters of the operation was carried out. The developed algorithm for designing a technological operation provides for conducting a test operation (installing and attaching the workpiece to the equipment, processing it at optimal modes) and monitoring the compliance of processing results with the requirements of regulatory and technical documents, analyzing defects and their causes, as well as forming a control effect. The control subsystem "Optimization of the process of rounding edges"is considered. Developed system for design of technological operations of processing of the edge elastic polymer-abrasive brushes allows you to assign the most effective tools and rational regime treatment parameters ensuring all requirements of normative-technical documents on the quality of processing at the highest productivity and lowest cost of operation.

Abstract: The purpose is to improve the machining efficiency of titanium alloy transpedicular screws on highperformance machine-tools based on the selection of advanced technological approaches, and to analyze the current manufacturing technology of implants on CNC machines of the semi-automatic longitudinal turning lathe type. The efficiency is assessed using the following criteria: process performance determined by the machine time and the quality of implant processing (surface roughness, geometric accuracy, mechanical properties). It is found that semi -automatic longitudinal lathes equipped with a collet feed system and drive heads for thread whirling allow processing the implants of the transpedicular screw type in a single set-up with maximum efficiency. It is shown that the machining technology of transpedicular screws is largely determined by the features of their design. The type and shape of the thread have the greatest influence on the used cutting tool and cutting modes. The analysis of screw breakages revealed that the main failure reasons are design defects and poor machining quality of the threaded part. It is determined that the use of the thread whirling method makes it possible to obtain the thread in one cutting pass and, therefore, significantly increase the machining performance compared to the traditional technology without any loss of quality. Additional advantages of this method are the reduction in the number of tools used and follow-on finishing deburring operations. Based on the conducted analysis the manufacture of transpedicular titanium alloy screws is recommended to perform using advanced cutting tools, primarily thread whirling cutters ensuring 4 times increase in machining performance without any loss of the processed item quality and 2 times reduced surface roughness. In this case the temperature in the cutting zone decreases, which has a positive effect on processed product service life. The condition for the effective use of the cutters is equipping of the machine-tools involved in the technological process with special drive heads.

The purpose of the paper is to reproduce a standard wind flow (laminar, turbulent, pulsating modes) to study the impact on crane structures, with the aim to obtain the load values of crane elements most closely approximate to real conditions. When creating an installation, which is related to the field of experimental aerodynamics, the "principle of simulating the main factors determined by the operating conditions of the research object" is adopted to ensure the r eproducibility of test results to the maximum extent. To confirm the performance efficiency of the proposed installation device, its computer model is developed using the CAD software SolidWorks. The computer model parameters are in full geometric agreement with the dimensions of the developed real installation. The use of the installation makes it possible to study the dynamic effect of the wind on the stability of crane structures in various operation modes (change in wind speed, in the mode of load operation, in operation conditions at the wall, etc.). The proposed installation allows to simulate the loads on crane equipment with the possibility of characteristics expanding, for example, its carrying capacity. The generated computer model of the installation makes it possible to reveal the physical picture of wind flow distribution at the installation outlet. The results of wind flow simulation on the proposed installation are confirmed on a computer model with a high degree of convergence of results at wind speeds of 2.5 m/s and lower The installation proposed by the authors will allow to simulate: the value of the real average statistical wind load of various intensity; pulsating component of the wind load; vortex excitation; increase of the available aerodynamic research capability for a real crane structure. The developed installation is a calibration device for external impacts of the wind force on the crane structure.

The purpose of the paper is to determine the conditions for the maximum transition of fluorine from the technogenic raw materials of primary aluminum production (mature sludge) into solution under alkaline leaching. The object of research is the mature sludge, which is formed from technogenic finely dispersed materials of aluminum production in the baths with Soderberg anodes (tailings of coal foam flotation, gas cleaning sludge, electrostatic precipitator dust) and stored close to the enterprise. Analytical studies of the initial sample and leaching products have been carried out according to the certified methods using chemical, X-ray phase and titrimetric analysis methods. It is shown that, the main percentage of the three sludge components belongs to the dust of electrostatic precipitators (~ 79.7%) and coal foam flotation tailings (~ 15.8%). It has been determined that the gas cleaning sludge features the richest composition of useful components (in the sum of F, Na and Al ~ 63%). According to the data of X-ray phase analysis, the sludge sample from the sludge storage mainly contains cryolite (up to 78.7%), carbon (11.9%), calcium-magnesium carbonate from the dolomite series (4.44%), and trace amounts of corundum and fluorite. The results of the conducted experiments on fluorine leaching from the sludge sample by the caustic soda solution allow to estimate the main process parameters: temperature - 75–80°С, duration - 60 min, NaOH concentration - 3.0% (with the W:T ratio of 10:1 and a stirrer speed of ~ 1005– 1010 rpm). According to the analytical data on the chemical composition of leaching cake, the fluorine content in the solid phase reduces by 88.1%. The experiments carried out on alkaline leaching of fluorine from the sample of mature sludge formed under primary aluminum production by the electrolysis of cryolite-alumina melts in the baths with self-baking anodes allowed to find out that the maximum decrease of fluorine content in the sample is achieved under the conditions of maintaining the process parameters including temperature, duration, reagent concentration in optimal modes.

This article is aimed at identifying issues associated with the use of solid cathodes in the electrolysis of cryolitealumina melts in order to determine conditions for their practical application. The contemporary technology of using solid anodes and cathodes is reviewed from its inception to the present time. The problems of stable electrolysis are discussed, such as effects of the electrode surface on the technological process. It is shown that all attempts undertaken over the recent 100 years to use solid electrodes, both reactive and inert, have been challenged with the emergence of electrolysis instability, formation of precipitates of varying intensity on the electrodes and impossibility of maintaining a prolonged process at current densities of above 0.4–0.5 A/cm2. Information is provided on the attempts to use purified electrolyte components with different ratios, metal-like and ceramic electrodes with a high purity and a smooth surface in order to approach real industrial conditions. However, to the best of our current knowledge, these experiments have not found commercial application. The authors believe that the most probable reason for the decreased current efficiency and passivation of solid electrodes consists in the chemical inhomogeneity and micro-defects of the bulk and surface structure of polycrystalline cathodes and anodes. It was the physical inhomogeneity of carbon electrodes that directed the development of the nascent electrolytic production of aluminium towards the use of electrolytic cells with a horizontal arrangement of electrodes and liquid aluminium as a cathode. This reason is assumed to limit the progress of electrolytic aluminium production based on the use of inert anodes and wettable cathodes in the designs of new generation electrolytic cells implying vertically arranged drained cathodes. The theoretical and experimental examination of this assumption will be presented in the following parts of the article.

The purpose of the article is to research the mechanism of gold-thiocarbamide complex sorption by activated carbons by studying the properties of the resulting electric double layer. The study of the electric double layer of coal sorption surface is conducted using a polar conductometric method based on the simultaneous use of polarization dependences on direct current and conductometric measurements on alternating current. It is shown that the sorption of thiocarbamide complexes of gold occurs more intensively at the cathodic values of sorbent potentials. Dependence of the adsorption value on the potential is actually linear in the negative region from 0.05 to 0.2 V. The absolute value of goldthiocarbamide sorption at the negative sorbent potential of 0.2 V coincides with the maximum values of the polarization current for direct current and conductivity for alternating current. The electrochemical reduction reaction of thiocarbamide compounds results in the formation of neutral thiocarbamide molecules, it might be the reason for gold deposition in a metallic form on the surface of the carbon sorbent. Neutralization of active compounds in the electric double layer creates conditions for the activation of positively charged gold ions directing to the negatively charged sorbent surface. The anodic region of sorbent polarization is characterized by the maximum values of gold ion sorption at the positive potential of 0.2 V. In this case the sorbent surface should be recharged, since in the same region of the potential the maximum AC conductivity is observed. Such conditions should lead to the destruction of the thick part of the electric double layer and, consequently, create favorable sorption conditions. The conducted studies allowed to derive a conclusion that the sor ption of gold-thiocarbamide complexes by activated carbons is significantly influenced by the sorbent potential. The use of the polar conductometric method for studying the electric double layer makes it possible to explain the features of given compound sorption on activated carbons.

The purpose of this article is study and identification of the most promising trends and engineering solutions in order to improve resource saving and energy efficiency in the production of corundum on the basis of the conducted patent review on melting improvement and optimization. The ways to optimize the corundum production are considered in three directions from the point of view of energy saving. The first direction relates to the development of promising engineering developments. The latter are studied to select rational operating modes and determine the main factors affecting voltage surges during the technological process and useful product yield. Consideration is given to the conditions for reducing specific energy consumption and improvement of production environmental friendliness at all stages beginning from isothermal sintering of corundum, production of electrocorundum, fine corundum to single corundum crystals. The second direction is the optimization of corundum production at all stages for the development of an optimal control algorithm for the technological process. In this case the electricity consumption might be reduced by 10-12% as compared to current standards. The third direction is the development of engineering solutions involving the change of individual structural units of furnaces, namely, the use of modern components and new heat insulating materials, as well as the application of spent heat carriers as the sources of secondary energy resources and the introduction of additional controllers of the automated control system of the process. The analytical study has shown that the result of optimization should be upgraded designs of plants and electrical equipment, which can provide maximum electrochemical efficiency, and corresponding furnace tightness. Criteria for energy supply and energy quality making possible to stabilize furnace material balance and solve resource saving issues have been developed. These measures allow to reduce the loss of raw materials up to 20-25%, the specific energy consumption under the production of corundum by 2-3 thousand kWh per 1 t.