Dmytro Sorokin

The priority tasks of grain production sustainability are solving the problem of the significant total energy consumption of the full production cycle and adapting the existing equipment to use as part of equipment sets of low and medium productivity. A promising way to solve these problems is the development and implementation of a string husking device. Its use will significantly reduce the energy consumption of buckwheat groat production due to the use of an energy-efficient husking mechanism. In addition, the string device makes it possible to eliminate the operation of the preliminary sorting of grain into fractions from the technological line of grain production, which additionally reduces the energy consumption of the line and makes it possible to use the husker in lines of low, medium and high productivity. Reducing the specific energy consumption of buckwheat production corresponds to the “European Green Deal” concept and makes production more resource-efficient and competitive. This way, two out of the three pillars of sustainability are improved: environmental and economic. The design principle of carrying out the operation of removing the shell from the buckwheat grain in the developed string husking device is substantiated. Theoretical studies were carried out using an analysis and synthesis of the mechanics of destruction and the method of determining the moments of inertia of homogeneous bodies relative to their own central axes during the husking of buckwheat by impact. Experimental studies were carried out using an experimental string husking device. The conducted analytical studies made it possible to determine the dependence between the specific energy consumption of the husking process and the physical and mechanical characteristics of buckwheat, as well as the structural parameters of the string husking device and the kinematic indicators of its operation. As a result of experimental studies, it had been established that the specific energy consumption of the buckwheat husking process in the developed device is 44–47% lower than the equipment currently used for buckwheat husking, and is 0.491–0.498 Wh/kg.

The level of renewable energy use and economic development of a country, as separate indicators, have an influence on the level of energy resource imports, but the mutual impact of renewable energy sources and gross national product on the growth or decrease of energy imports dependency have not been studied. Therefore, the aim of this study was to evaluate the energy security of European countries by taking into account the consumption of renewable energy sources and the economic development of the countries. In particular, the article examines the relationship between energy import dependency, gross domestic product (per capita), and renewable energy sources in 27 countries in the European Union. Regression analysis of data on EU countries for 11 years (from 2011 to 2021) was used to determine the non-linear influence of gross domestic product and renewable energy use on energy import dependency. This influence was simulated by a second-order regression equation. The analysis of the equation for extremes made it possible to conclude that with a share of energy from renewable sources at the level of 32%, the economic development of a country does not require an increase in energy import dependency, and with larger values of energy from renewable sources, a decrease in energy import dependency may occur. In addition, according to the analysis of the obtained mathematical dependence, it is recommended that countries with a gross domestic product of up to 10,000 euros per capita use renewable energy sources at the level of 40%. For the countries with a domestic product of up to 30,000 euros per capita should use renewable sources at the level of 50%. For countries with a gross domestic product of more than 30,000 euros per capita, renewable energy sources at a level of more than 55% is recommended. A high level of renewable energy use will allow a country to increase its gross domestic product without a significant increase in energy import dependency, and at the level of renewable energy sources of more than 32%, an increase in gross domestic product does not actually lead to an increase in energy import dependency. An increase in the use of renewable energy sources above 40% of the total consumption of energy resources in a specific country, in particular, and in the European Union, in general, will ensure an increase in energy security and an increase in the level of energy independence.

The purpose of this work is to develop a model for balancing the processes of the generation and consumption of electricity, taking into account the random nature of these processes. The subject of the study is hybrid power systems that use traditional and renewable energy sources and have the properties of a local network. Such systems are sensitive to variable generation modes, and the presence of rapid changes in power requires short time intervals. The presence of wind and solar power plants makes it difficult to ensure a balance of power, which increases the need for intermediate energy storage. The research method is a mathematical modeling of random processes of energy consumption and generation, which allows for the analysis of the current power balancing and the obtaining of the integrated characteristics of the state of energy storage and reuse. The unique goal of the study is to take into account the power gradients and the state of charge of the batteries. The results of the study allow for the comparison of the different configurations of the power system in terms of balance, storage needs, and energy loss. It has been shown that the increase in battery capacity and speed limitations are nonlinearly related to the possibilities of energy conservation and the probability of the incomplete use of the capabilities of the energy storage system.

One of the main trends in the development of modern engine building is the use of biodiesel fuel, which can lead to a decrease in the reliability of engines that are not adapted to it. However, at present there is no general method for determining the reliability of fuel systems of internal combustion engines. In this paper, a reliability model of engine fuel systems when operating on biofuel has been developed. Comprehensive indicators for assessing the reliability of diesel engine fuel systems are the coefficient of readiness and technical use. The availability factor of the fuel system when operating on biodiesel fuel without the replacement of structural materials was 0.66, while with the replacement it was 0.71, and the coefficient of technical utilization without replacement of materials was 0.36, and with the replacement of 0.4. Recommendations are given to improve the reliability of the engine fuel system components. The resulting model allows for complex comparisons of the effectiveness of various ways to improve the reliability of engines running on biodiesel fuel.

Hydrogen production from biomass may become one of the leading areas of bioenergy in Ukraine soon.Currently, the main direction of biomass energy production in Ukraine is the production of thermal energy for distributed heat supply of enterprises and private households by burning biomass of wood and agricultural origin. Nowadays in Ukraine, there is a technology for the production of biohydrogen. We calculated the environmental and economic effects of hydrogen production as a source of energy. We have come up with the following conclusion that if there is a demand for the final product, hydrogen production will be attractive from economic standpoint and will not require a green tariff or other support from the government.The market price of biohydrogen will be $ 4-5 per kg and will be comparable to that which the European Union aims to achieve.We assume that hydrogen may be a cleaner source of energy for end users, especially in the transport sector in the future. One of the main issues of Ukraine's possible participation in Europe's hydrogen energy program as a supplier and producer of renewable hydrogen is the possibility of its technically safe and cost-effective transportation to EU countries. As the main hypothesis considered transportation of hydrogen using the gas transmission system of Ukraine as part of a mixture with natural gas. Calculations show that, of course, obtaining energy from hydrogen, even in mass production, will be more expensive than alternative traditional and non-traditional methods. The development of this technology, in any case, is promising in terms of the development of energy independence and environmental development of states. The effect of scale in mass production of hydrogen energy should also work, which will significantly reduce the cost of this technology.

Hydrogen is increasingly considered as an environmentally friendly energy source as it stores a large amount of chemical energy per unit mass (142 MJ·kg⁻¹) that can be released without the emission of combustion by-products. The presented research is based on simulation modeling of biohydrogen production projects from agricultural waste. Based on the probability theory and mathematical statistics, the models of the variable market value of biohydrogen and natural gas are substantiated. The results of the research indicate that in 2019, projects regarding the production of biohydrogen from agricultural raw materials were mostly unprofitable for the investors. However, starting in 2030, the forecasted return on investment in biohydrogen production projects from agricultural raw materials indicates that such projects will be profitable for investors, and the number and scale of such projects will significantly increase worldwide.

In this article, an integral mathematical model was obtained for calculating the force, which acts on a permanent magnet or ferromagnetic body in systems with axial symmetry. The case of constant currents in the system is considered. This mathematical model can be extended to the presence of alternating currents and the influence of motion on the electromagnetic process. which will be discussed in the following publications. The adequacy of the obtained models is confirmed by comparing the intermediate results with the solution of finite element methods. The obtained simulation results will allow analyzing the distribution of forces acting in the system. and to solve the problems of synthesis of magnetic systems with given characteristics. It is shown that the problem of calculating the components of the magnetic field induction vector in the presence of permanent magnets and ferromagnetic elements can be rather complicated and requires an understanding of the processes occurring in the system.

the article presents an integro-differential mathematical model of the distribution of eddy currents in a conductor with axial symmetry. Depth of penetration of eddy currents is calculated depending on the power frequency. The simulation results obtained will allow us to select the basic sizes of the elements of the induction heater and to investigate the electrical parameters depending on the material to be heated. It is shown that the task of simulating the induction heating process to obtain information about the required modes in different heating zones of the workpiece as a control object is very complex.

In this paper the mathematical model intended for calculation of the magnetic field in the working area of the coaxial linear motor with permanent magnets is developed.