Volume 335, Nº 5 (2024)

Relevance. Real time hardware and software systems are operated in power system operation centers. In these systems the state estimation block is one of the key one, since in accordance with the regime parameters results, derived from this block, the more comprehensive parameters can be calculated. These parameters are reckoned for system stability and reliability. Today telemetry and synchronized phasor measurements are used for parameters estimation. Therefore, the state estimation methods development is a relevant task.

Aim. Development and practical evaluation of the regime parameters estimation synthesized method for using in real time hardware and software systems. The synthesized method permits to improve estimation accuracy and decision quality of focal points coming from system stability and reliability stabilization.

Methods. Proposed me-thod is based on mathematical frameworks of Gauss–Newton method and extended Kalman filter when telemetry and synchronized phasor measurements arrays are simultaneously utilized.

Results. The synthesized method of power systems regime parameters estimation at steady-state and post accident conditions is developed and evaluated.

Conclusions. It is confirmed, that presented synthesized method increases accuracy of the voltage and active power flow estimation at steady-state and post accident regimes, thereby enabling the improved accuracy of maximum allowed active power flows and control action volumes in contrast to the standard state estimation method. Developed software provides an opportunity to implement this method into the state estimation block of real time hardware and software systems. The upcoming trends for state estimation methods development in the event of dynamic processes in power system areas are also formed.

Relevance. Tense ecological situation in the impact zone of the large industrial complex of Usolye-Sibirskoe on the Angara river, search for sources and ways of pollutants inflow during different periods of technogenic load, necessary to assess and forecast the current changes in the aquatic ecosystem.

Aim. To study chemical composition of wastewater from the industrial zone of Usolye-Sibirskoe during different periods of technogenic load and assess their impact on hydrochemical parameters of the Angara river water.

Objects. Wastewater from the industrial zone of Usolye-Sibirskoe and Angara river waters in the impact area during the period of high technogenic load (2010) and the period of its reduction (2020).

Methods. Chemical composition of wastewater and natural water was determined in the Center of Collective Use «Isotope-Geochemical Investigations» of Vinogradov Institute of Geochemistry SB RAS (Irkutsk, Russia). Concentrations of major ions in waters were measured using a set of methods generally accepted in hydrochemistry (atomic absorption and atomic emission flame spectrometry, spectrophotometry, potentiometry, titrimetry), Hg concentration was measured using atomic absorption spectrometry, concentrations of other trace elements – using mass spectrometry method (ISP MS).

Results. The authors have revealed significant changes in chemical composition of wastewater of the industrial zone in different periods of technogenic load, reflecting the transformation of pollution sources during the liquidation of technogenic objects of the area. Over the ten-year period particularly important changes are expressed in a significant decrease of Hg, Al, Cs, Ti, Cr, Cl^– and Na⁺ concentrations and increase of Mn concentrations in the wastewater of the industrial zone. This is reflected, in its turn, in the dynamics of hydrochemical composition of Angara river water in the impact area. In 2010 a regular consecutive decrease of most of elements concentrations was observed with distance of Angara river waters from technogenic sources. In 2020 their spatial distribution is opposite: with a significant decrease in concentrations of most of the studied elements at the river site 50 m downstream of industrial discharges, their increase was detected at more distant monitoring stations (1.5 and 5 km) where Mn, Cu, Cd and Tl concentrations were the highest. Despite significant changes in wastewater chemical composition in different periods of technogenic load, the Angara river waters at all monitoring stations in the impact zone of the industrial complex of Usolye-Sibirskoe are polluted.

Relevance. At present, the problem of soil pollution with heavy metals, which are accumulated in the body of animals and plants, causing various toxic effects, is especially acute. Despite the existence of various methods of reclamation of disturbed lands, as a rule, their application is inefficient or expensive, especially when it comes to abnormally high concentrations of heavy metals. Thus, an extremely urgent task is to find effective and inexpensive ways to recultivate lands contaminated with high concentrations of heavy metals. The article considers one of the promising areas for the reclamation of such lands using a mixture obtained from the accumulated waste of lignin-containing sediments from the pulp and paper industry of Baikal Pulp and Paper Mill as sorbents.

Aim. To study and evaluate the effectiveness of using a mixture, which includes frozen lignin-containing sediments of Baikal Pulp and Paper Mill, as heavy metal sorbent.

Methods. To assess the sorption efficiency of the obtained sorbent from the frozen sediments of sludge-lignin, the samples of anomalously contaminated soils were taken from the industrial site of the former battery plant "Vostsibelement", located in Svirsk, Irkutsk region. To determine the surface structure of the obtained sorbent for the presence of micro-, meso-, and macropores, its surface was surveyed using a JEOL two-beam system. IR spectroscopy was used to establish the types of bonds between the sorbent and the extracted metals.

Results. The studies have shown that the resulting sorbent from the frozen lignin-containing sediments of Baikal Pulp and Paper Mill has a porous structure with a predominance of mesopores, sorbing heavy metal ions, while a large number of micropores contributes to the occurrence of chemical sorption. The obtained IR spectra indicate the possibility of chemical sorption of lead as a result of the reaction of substitution of a hydrogen atom in various hydroxyl groups of the sorbent of the group of aromatic or carboxyl structures. At the same time, the resulting sorbent in terms of its sorption properties is not inferior to commercial natural sorbents – bentonite clay and grassroots peat. The conducted studies allow us to make a positive conclusion about the possibility of using the developed mixture as a sorbent for the immobilization of heavy metals during the reclamation of lands that are contaminated with high levels of heavy metals, including lead.

Relevance. Today, increasing attention of the world community is being paid to the problems of ecology and global warming. Objective prerequisites are emerging for more active introduction of renewable energy sources and energy carriers into thermal and electrical energy production cycle. But non-traditional energy sources, such as wind generators and solar panels, have a number of significant disadvantages, the main one of which is that the stability of renewable energy sources depends significantly on weather conditions and time of day. For this reason, the governments of many countries are already discussing new programs for the development of the economy energy sector based on the large-scale construction of nuclear and thermal power plants. This global problem can be solved by switching to wider use of coal as an energy source. Coal thermal power plants provide stable production of thermal and electrical energy, unlike renewable energy sources. But coal is a “dirty” fuel – when it is burned, it produces significant amounts of anthropogenic emissions, such as carbon dioxide, as well as sulfur and nitrogen oxides.

Aim. Experimental studies of the conditions and characteristics of ignition (thermal preparation times) of humidified coal of several fairly common and widely used brands and the amount of nitrogen oxide in their combustion products.

Object. Humidified coal of four grades (lean, long-flame, anthracite and brown).

Method. To establish the main characteristics and conditions of coal fuel ignition and combustion under high-temperature heating conditions, a special experimental stand was used.

Results. The results of experimental studies are presented to substantiate the possibility of using four grades of humidified coal as the main fuel in thermal power engineering. The authors have established nitrogen oxide sequestration in the combustion products of the latter in a small vicinity of a humidified coal particle in comparison with dry coal under high temperature conditions. The experimental studies established as well an insignificant (increase of no more than 11%) influence of additional humidity on the thermal preparation times of single coal particles for the four studied grades of coal.

Relevance. With the restructuring of the economy in the carbon-neutral side, the negative anthropogenic impact can be weakened. It is very likely that there will be a comprehensive analysis of the impact of various climatic accidents in the country and its action to eliminate the risk of carbon dioxide. Moreover, studies in the experience of the peoples of the states make it possible to use their achievements in the field of climate policy in Russia, improve and modernize their advantages from the characteristics of the national economy.

Aim. To assess the degree of impact of environmental, climatic and macroeconomic factors on the change in the carbon intensity of the economies of the world.

Objects. The parameters of the climate policy of the countries of the world in the field of regulation of carbon dioxide emissions. The subject of the study is the relationship of environmental, climatic and macroeconomic factors with the carbon intensity of the economies of the world.

Methods. Econometric method of panel data analysis.

Scientific novelty. The paper confirms the hypothesis of the negative impact of one of the main climate policy instruments of the countries of the world (carbon prices) on the carbon intensity of the economy using the construction of the original panel data model.

Results. The authors have substantiated a set of factors that affect the carbon intensity of the countries of the world, supplemented by such an indicator as the carbon price, which is one of the main indicators of climate policy development in the country. All factors were divided into two groups (macroeconomic and ecological-climatic) and a database was formed for 24 countries. Using the panel data method, the authors constructed the equation of the dependence of the carbon intensity of the economies of countries on macroeconomic and ecolo-gical and climatic factors. The authors tested the hypothesis of the carbon price negative impact on the carbon intensity of the economies of countries. Evaluation of various model specifications allowed us to confirm this hypothesis, which indicates the importance of the climate policy development within each country and the feasibility of introducing new tools to regulate carbon dioxide emissions. It was also determined that GDP, as a general indicator of the development of the entire economy, has the greatest impact on reducing carbon intensity. At the same time, in order to reduce the ratio of carbon dioxide emissions to gross domestic product, it is necessary to pursue a policy of replacing fossil fuels with low-carbon energy sources, but only taking into account the country raw material capabilities and the industry specifics of the economy.

Relevance. Control of energy state of reservoirs is an integral part of the overall system for monitoring the development of hydrocarbon deposits. The traditional way to control the energy state of reservoirs is to build isobar maps, while the input data are the materials of well tests in unsteady conditions. In the current technical and economic conditions, it should be considered impossible even conditionally simultaneous shutdown of the entire well stock for the actual determination of reservoir pressure. This shortcoming is devoid of indirect methods for determining reservoir pressure. In this regard, it seems relevant to compare direct and indirect methods for determining reservoir pressure when using their data to analyze the energy state of hydrocarbon deposits.

Aim. Comparative assessment of direct and indirect methods for determining reservoir pressure in the analysis of the energy state of deposits (when constructing isobar maps).

Object. Tournaisian-Famenian carbonate depo-sits of oil from the fields of the Perm Krai.

Methods. Well tests, analysis of production history by wells (module Topaze (Kappa Workstation)), machine learning methods (modular service Data Stream Analytics (DSA)), mapping, correlation analysis.

Results. Well tests carried out at different times do not allow a reliable assessment of the current energy state of reservoirs, in contrast to indirect methods for determining reservoir pressure, the practical implementation of which allows obtaining the desired value for any date. However, with conditionally the same high predictive ability of indirect methods, the considered methods of machine learning should be considered a priority. This is due to their advantageous characteristics, such as low duration of computational operations, a minimum set of initial data, an integrated mapping service.

Relevance. The article provides a comparative analysis of micro-hydroelectric power stations with a hydraulic unit regulation along a hydrogenerator anchor circuit according to technical and economic efficiency. The authors substantiate the possibility of using intelligent control of the energy balance of inverter micro-hydroelectric power stations for increasing the amount of electricity generated without increase in the installed capacity of the hydraulic unit. This will improve their technical and economic characteristics compared with traditional micro-hydroelectric power plants of the ballast type. This approach allows using intelligent control systems that can regulate power generation depending on the peaks of electri-city consumption. For this purpose, inverter micro-hydroelectric power stations are used. They allow more efficient management of energy consumption and accumulation of electricity in batteries. The developed control algorithms make it possible to optimize the operation of micro-hydroelectric power stations, ensuring maximum resource efficiency and reducing the cost of electric energy. Application of these technologies may significantly improve economic indicators of micro-hydroelectric power stations and make them more competitive in the electricity market. The algorithms control the hydraulic unit operation, ensure supply of electric power to consumers and effective use of energy storage batteries depending on electric needs.

Aim. Comparative technical and economic analysis of a micro-hydroelectric power station with regulation of the parameters of the generated voltage along the anchor circuit of the hydrogenerator driven by an unregulated hydraulic turbine.

Object. Micro-hydroelectric power stations of diversion type with power converters and electricity storage devices.

Methods. Computer modeling.

Results. The authors have proposed the classification of diversion micro-hydroelectric power stations with hydraulic unit control via the hydrogenerator anchor circuit. The paper demonstrates the technical and economic possibilities of various methods of their construction. The most promising technical solutions for inverter micro-hydroelectric power stations are determined, their energy balances and power equipment control algorithms are optimized.

Relevance. The need to analyze the current state of the subject of coal drying in order to identify the most effective methods in terms of time and energy costs, as well as environmental safety and improve the quality of fuel. As practice shows, drying is one of the most important stages in coal preparation for combustion, it helps to increase thermal efficiency, reduce emissions and environmental pollution, increase energy capacity and improve combustion stability. Among the main me-thods of drying coal, drying with evaporation: A) rotary drying; B) drying in a fluidized bed; C) immersion drying with hot oil; D) drying in a microwave oven, as well as drying without evaporation: A) hydrothermal dehydration; B) mechanical/thermal dehydration; C) solvent extraction, can be distinguished. At the same time, each of these methods is constantly evolving and it is required to evaluate the influence of the dynamics of these changes on the key characteristics of drying.

Aim. Review and analysis of modern methods of coal drying, the most efficient in terms of time and energy costs.

Object. Wet material – coal, subjected to various drying methods.

Methods. Search for works on the stated topic, checking the indication of the main drying parameters: time, energy consumption, etc. Based on the data obtained, a comparison of various drying methods was carried out, and optimal methods were recommended.

Results. The authors have considered the modern methods of drying coal and assessed their effectiveness. Rotary drying, hot oil immersion drying, mechanical/thermal dehydration and solvent extraction were found to be the most energy efficient methods for drying coal. The paper considers the features of each drying method.

Relevance. Like many deposits of Western and Central Siberia, the Sakhalin Island deposits (the considered Vostochno-Lugovskoe gas field) faced the problem of gas hydrate formation in wellbores, well plumes and equipment integrated into the technological chain. Hydrate formations clog wells, pipelines and gas pipelines, reducing their working cross-section area. This leads to decrease in flow rate or a complete stop of equipment operation. The operation of valves, measuring instruments, separators and fittings is also disrupted. All this leads to significant economic losses and reduces the efficiency of the field development and operation. The fields that are at the late stages of operation are subject to the greatest influence due to the impossibility of ensuring a hydrate-free operation of wells. From the point of view of the development rationality, it is more profitable to prevent the formation of hydrates than to deal with already formed deposits. It is also worth noting the expediency of transferring the location of hydrate deposition from the well to the surface, where it is much easier and more cost-effective to deal with this complication than in the well. This can be achieved by influencing the parameters of the deposit formation, from which it is impossible to influence the gas composition. Shifting the equilibrium conditions for the formation of hydrates by increasing salinity is also inefficient, since the risk of salt deposition and corrosion increases. Thus, it remains possible to regulate thermobaric parameters by changing a well technological mode of operation, thermal insulation or coating the inside of the tubing with materials, as well as downhole electric heaters, which exclude the possibility of deposit formation.

Aim. To substantiate the technology for increasing the efficiency of production wells in the conditions of hydrate formation.

Objects. Gas wells operating in the conditions of hydrate formation, as well as the relationship and dependence of the operating parameters of the well and other technological parameters on the potential for the formation of hydrates.

Methods. Analysis of the geological and physical conditions and the state of development of the Vostochno-Lugovskoe gas field; computer and mathematical modeling of well operation in the field under conditions of hydrate formation; analysis of ways to prevent the formation of hydrates and the choice of technological solutions.

Results. The problem of hydrate formation is widespread in gas fields. Hydrates can partially or completely block the working section of production wells, reducing or completely stopping production. As a result production wells are idle for an average of 18 hours per month. This entails economic losses and interferes with the stable operation of the well. It is shown that due to the specifics of the operation of wells of the Vostochno-Lugovskoe gas field, changing the technological regime to hydrate-free at the moment is impossible. According to the results of well operation simulation, the main temperature losses occur due to heat removal through the tubing. Among the ways to prevent the formation of hydrates, thermal insulation of tubing, partial silicate-enamel coating, the use of a heating cable and methanol are considered. Based on the results of the evaluation of economic and technological efficiency, a heating cable technology was selected with the installation of a turbo-expander to compensate the cost of electricity, as well as the descent of the second row of tubing to the depth of the potential place of hydrate formation in order to increase the heating efficiency and injection coolant or inhibitor directly into the hydrate formation interval.

As it is known, Rudny Altai is a classic province of sulfide deposits, most of which were formed in paleo-island-arc geodynamic settings. Pyrite ores have a complex and diverse chemical composition, including a wide range of impurity elements, among which the metalloid tellurium and the metal bismuth still remain poorly studied. Based on the above, we investigated tellurium-bismuth mineralization in the sulfide ores of the Maleevskoe deposit, confined to the Zyryanovsky cluster of Rudny Altai.

Relevance. The lack of information about the nature of the distribution and forms of occurrence of this type of rare minerals in the ores of pyrite deposits of Rudny Altai. The data obtained from this study will allow for more comprehensive processing and use of mineral resources.

Aim. To characterize the material composition of ores; identify the features of the development of tellurium-bismuth mineralization and determine the conditions for its formation; assess the prospects for associated mining and extraction of tellurium with bismuth from the ores of sulfide deposits of Rudny Altai.

Object. Tellurium-bismuth mineralization of sulfide ores of the deposit.

Methods. Petrographic, mineragraphic and mineralogical analyses, scanning electron microscopy in combination with X-ray microanalysis and Raman spectroscopy.

Results. The ores revealed a variety of tellurium-bismuth mineralization, which is recorded as independent minerals, represented by sulfosalts, tellurides, oxides, and native forms of isolation. Such minerals as plumbotellurite PbTeO₃, cervelleite Ag₄TeS, xilingoite Pb₃Bi₂S₆ and an unidentified mineral with the general formula PbAg₂Te were discovered for these ores. Minerals of tellurium-bismuth composition in relation to the main ore minerals are characterized by later crystallization into the Ag-Te-Bi-sulfide association of the ore stage at a temperature of 280...150°С. Based on the data obtained, the authors predicted the prospects for tellurium and bismuth extraction from ores of deposits similar in material composition to the Maleevskoe deposit and confined to the ore cluster of the same name.