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Vol 67, No 5 (2024)
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https://doi.org/10.21122/1029-7448-2024-67-5

GENERAL POWER ENGINEERING

381-392 305
Abstract

Solar energy is one of the most important and promising energy sectors in the world. Batteries that convert sunlight into electrical energy could become a replacement for traditional carbon-based energy sources. Vertical thin-film solar batteries are one of the new approaches to solar energy generation. The vertical configuration of solar panels provides maximum absorption of sunlight throughout the day. This orientation allows the batteries to capture solar energy even at low angles of incidence of the sun’s rays, which prolongs their operating time and improves the efficiency of electricity production. In this work, the authors proposed a three-dimensional model of a vertically oriented solar battery, as well as they calculated and evaluated the temperature characteristics and the efficiency obtained under conditions of changing ambient temperature. Herewith the power densities of concentrated solar radiation with maximum values from 1 to 10 kW/m2 were varied. The distribution of the maximum values of the surface temperature of the solar battery has been studied. Also, the dependences of the maximum values of the solar battery temperature and the temperature gradient inside it, as well as the dependences of the minimum and maximum values of the heat flux from the solar battery surface on the time of day in the middle of January and July have been studied and plotted. As the calculations have shown, the maximum values of the temperature gradient inside the solar battery in January are ~47–50 % higher than in July. The potential difference, generated by the battery, reaches its maximum values from 11 a.m. to 4 p.m. both in January and July. The use of vertical thin-film solar batteries will improve the power generation efficiency and lower operating costs by reducing the influence of dust, rain and snow.

ELECTRICAL POWER ENGINEERING

393-410 486
Abstract

Due to the growth of “green” energy, the need to regulate the load on large power systems, and the development of electric transport, electricity storage systems (ESS) are increasingly, being used in the world. Conceptual documents have been developed in the Republic of Belarus and the Russian Federation stating the need to modernize the regulatory framework for the use of ESS, create scientific support for the development of ESS technologies, centers of competence and of the implementation of pilot projects. This article provides an example of calculating the economic effect of using ESS at an industrial enterprise. A methodology is proposed that can be used to develop standardized methods for calculating the economic effect of using ESS at enterprises and in local energy systems of consumers of various types. The main functions performed by the ESS at the enterprise are characterized. The features of calculating the economic effect of performing these functions under the conditions of the statistical nature of the load regime of the enterprise are considered. Calculations of the simple payback period for investments in the installation of an ESS for an enterprise with several options for payment terms for electricity are given. It is shown that the economic result of using ESS significantly depends on both the pricing conditions and load schedules of the enterprise, as well as on specific requirements for the quality and reliability of power supply and should be evaluated individually in each case.

411-424 380
Abstract

One of the directions of development of the electric power industry is decentralization, aimed at improving the reliability of energy supply, reducing losses during transmission of electric energy and ensuring energy independence of consumers. It is possible to simulate decentralized power systems, including distributed generation facilities, by implementation of multi-agent systems that allow solving design and control problems taking into account the needs of each participant in the process of production, transmission, distribution and consumption of electricity. The development of distributed generation using a multi-agent approach requires the creation of models for assessing the technical and economic efficiency of decisions made by each agent, both at the strategic and tactical levels. The strategic decisions of agents related to distributed generation include, among other things, the creation of power facilities and power plants based on renewable energy sources. An important factor for making such decisions is the estimation of the capacity factor. However, currently there are no models for its estimation with high reliability. The present paper proposes a new algorithm for estimating the capacity factor for the entire territory of a certain administrative unit and a model for its forecasting based on climatic and geographical parameters. The study was conducted on a data sample of 221 generation facilities (solar and wind power plants) in four oblasts (regions) of the Russian Federation. It has been determined that the capacity factor can be forecasted with a mean error within 4 % for photovoltaic power plants and 9 % for wind power plants. Therefore, it is possible to use the developed algorithm and model both in decision support systems when choosing the location of this types of power plants, and in systems that model the development of power systems using a multi-agent approach.

HYDRAULIC POWER ENGINEERING

425-439 257
Abstract

The paper presents an experimental study of an assembly of five stages of an electric centrifugal pump (ECP) installation, the flow part of which is modified according to the principles of biomimetics, namely using the “lotus leaf effect”. The object of the study was a 5A-35 ECP. The surfaces of the blade systems of impellers and guide devices of stages 5 A-35 were hydrophobized using the method of applying surfactant layers. The degree of impellers hydrophobicity was estimated by the wetting angle average value measured by three drops at three different points on the impeller surface. The impellers surface roughness under study was determined by the arithmetic mean profile deviation Ra and the profile height irregularities Rz. The issues related to the surfactant coating modification effect salt deposition and corrosion were studied. For this purpose, the surfaces of the original and modified impellers were subjected to intensive forced salt deposition as a result of prolonged exposure to saline solution. The conclusion about the samples corrosion resistance degree was made by changing their mass, which was due to the salt deposits formation during 15 hours of stay in solution, as well as using the drop method. Both methods have shown that the surfactant coating can serve as a salt deposition inhibitor, and the pump impeller modified by it has increased corrosion resistance. Thus, during comparative tests, a smaller mass of salt was deposited on the modified impeller sample during 15 hours of exposure in saturated saline solution than on the original sample. This indicates that the surfactant layer prevents the salt deposits fixation on the working surfaces of the pump stage. On the modified sample examined by the drop method, the indicator color changed in 20 minutes, and on the original one – in 2 minutes. Experimental studies have been carried out, during which the operation energy parameters of a five stages 5A-35 pumping package with initial and modified surfactant-coated impellers have been determined. The studies have shown a 2 % increase in efficiency in the pum-ping package of stages with modified impellers. The results of the study can be useful in the oil production, chemical industry, as well as in the housing and communal services sector.

440-451 250
Abstract

The development of the industrial sector and the increase in production capacity have a positive effect on the economic situation of the country, but not on environmental safety. Insufficiently purified and polluted wastewater is constantly discharged into water sources, the amount of which directly depends on the industrial development of the region. Thus, the anthropogenic load on the Oka River affects the composition of water in the source, there are often bursts of instantaneous emissions, as well as the flowering of phytoplankton in the summer. The latter further significantly reduce the efficiency of water purification to drinking quality. Therefore, the development of technologies that will be able to maintain purification at the required level is an urgent task. The article presents the method of charcoalization, which allows to neutralize pollution in a short time and improve the water treatment quality. An industrial experiment of the developed technology was carried out at an operating water treatment plant with testing of two extreme do-sages of sorption material. The optimal dose of coal pulp was determined, the impact on significant purification performance was described, and the technological solutions have been developed to determine the point of coal pulp input and the dosage multiplicity. The conducted research has made it possible to expand knowledge in the field of drinking water preparation and to determine significant water parameters that are affected by the sorption purification method.

POWER ENGINEERING ECONOMICS

452-470 278
Abstract

The article reviews international acts in the field of combating climate change (United Nations Framework Convention on Climate Change, Kyoto Protocol and Paris Agreement), identifies the main trends in the field of carbon regulation: emissions quoting; implementation of climate projects; introduction of greenhouse gas reporting and expansion of the legislative framework. A comparative analysis of the national legislation in force in the Republic of Belarus and the Russian Federation is carried out, its conditional classification is considered with the allocation of carbon regulation instruments being applied, viz. the market ones, the restrictive ones, the supporting ones and the auxiliary ones. The regulation of greenhouse gas emissions should include a wide range of activities and cannot be reduced solely to restrictive instruments. Market instruments include the national emissions trading system, international voluntary markets and instruments of international cooperation, while restrictive instruments include the introduction of carbon taxes, quotas, and mandatory carbon reporting. Among the examples of supporting instruments subsidies, targeted financing and tax preferences, as well as information policy may be noted. Auxiliary instruments include methodologies for quantitative assessment of greenhouse gas emissions and uptake, carbon reporting standards and tools for verification of reporting on greenhouse gas emissions, legislated possibility of implementing climate projects. The normative national regulation regarding the accounting of greenhouse gas emissions is considered, the categories of emission sources and greenhouse gases whose emissions are subject to accounting are identified. It is important to note that the legislation on greenhouse gases in the Republic of Belarus and the Russian Federation, as well as around the world, has not been finalized and is in the process of formation.



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ISSN 1029-7448 (Print)
ISSN 2414-0341 (Online)