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Browsing Статті КТ by Author "Gabrіnets, Volodymyr O."
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Item Computer Modeling of Air Pollution in Case of Dust Cloud Movement in Open Pit Mine(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaieva, Viktoriia V.; Kirichenko, Pavlo S.; Berlov, Oleksandr V.; Gabrіnets, Volodymyr O.; Horiachkin, Vadym M.ENG: Purpose. Explosions in open pits lead to the formation of dust clouds. These clouds lead to intense air pollution. An important task is the development of methods for predicting the dynamics of atmospheric air pollution during ex-plosions in open pits. The purpose of this work is development of a numerical model to predict atmosphere pollution after explosion in open mine pit. The task is to develop a numerical model that would allow for the calculation to take into account the geometrical shape of the open pit mine, the parameters of the meteorological situation (wind speed, atmosphere), the shape of the dust cloud that is formed in the open pit mine at the site of the explosion. Methodology. Mathematical modeling of dust cloud dispersion during an explosion in an open pit mine is based on the use of fundamental equations of aerodynamics and mass transfer. The airflow velocity field in the open pit mine is modeled using the Laplace equation for the velocity potential. The formation of the concentration field of dust is mod-eled on the basis of the equation of convective-diffusion dispersion of an impurity. For numerical integration of model-ing equations, difference schemes are used. The Laplace equation for the velocity potential is numerically integrated using the Richardson method. For the numerical integration of the convective-diffusion dispersion equation for an im-purity, an implicit difference splitting scheme is used. Findings. A CFD model has been developed that allows you to calculate the formation of pollution zones during the movement of a dust cloud in the open pit mine. A feature of the developed model is the speed of calculation. For practical use of the developed model, standard input information is required. Originality. In contrast to the existing models in Ukraine, the developed numerical model allows taking into account the geometrical shape of the open pit mine and the geometrical shape of the dust cloud when making predictive calculations to assess the level of air pollution caused by explosions in open pits. Practical value. The developed nu-merical model can be implemented on computers of low and medium power. For practical use of the numerical model, standard information on meteorological conditions in open pit mine is required. The numerical model can be used for environmental assessment of the effect of explosions in open pit mine on environmental pollution and work areas.Item Determination of Features of Formation of Energy Supply Systems with the Use of Renewable Energy Sources in the Transition Period(ПП «Технологічний Центр», Харків, 2021) Nakashydze, Liliya V.; Gabrіnets, Volodymyr O.; Mitikov, Yurii; Alekseyenko, Sergey; Liashenko, IrynaENG: An urgent scientific and practical problem is the formation of energy efficient systems for ensuring climatic conditions in premises based on the use of renewable energy sources. The work has improved the technical and methodological approach to the calculations of energy supply and storage systems when using energy-active fences. The special effectiveness of these fences has been shown in the transitional periods of the year, that is, in spring and autumn. A mathematical model has been developed to reliably predict the process of ensuring temperature comfortable conditions (heat balance) when using nonparametric statistics methods. It will improve the quality of forecasting the effect of external air temperature during the transitional periods of the year. The temperature inside the room is taken into account in the presence of a multilayer energy-active fence. To determine the approach to the use of heat in energy supply systems during the transition period, thermal parameters from the inner and outer sides of the building structure are considered. This makes it possible to take into account changes in the heat transfer of these structures when designing a power supply system and determining the optimal modes of its functioning in various natural conditions. The function of energy-active fences associated with the generation of additional heat into the system, obtained through the conversion of solar radiation energy, is considered. To increase this generation, special multilayer designs of energy-active fencing have been proposed. The proposed thermal modernization with the use of energy-active fences allows, on average, over the cold period of the year, to reduce energy consumption by 3.5 times for industrial and residential buildings.Item Improving the Efficiency of the Heating System for Public Buildings Infrastructure in the Context of DNURT(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2016) Pshinko, Oleksandr M.; Kuznetsov, Valeriy; Yatsenko, Dmytro K.; Gabrіnets, Volodymyr O.EN: Purpose. The paper analyses the possibility and terms of increasing the efficiency of heating and ventilation systems of public buildings at the present stage of development and the specific climatic conditions of Ukraine. The main purpose is to develop specific measures for public buildings, which will lead to a significant reduction in energy costs for heating and air conditioning system. The example is similar system of DNURT compact campus, which is heated with its own autonomous boiler that uses natural gas. Methodology. The statistical heat loss analysis for the last 5 years allows defining the types and calculating the heat loss values for specific conditions. These losses are compared with those in the world practice and based on the comparison and analysis of the current system there are offered the ways to reduce the heat loss values through the use of various technical and organizational methods. The paper also proposes involvement for this purpose of secondary and alternative energy sources. The secondary energy resources include the heat that is emitted by people and that coming out with the air during ventilation of buildings. The renewable sources include solar and geothermal energy. To enhance the heat transfer medium temperature capacity it is proposed to use the heat pumps. Findings. The maximum possible use of the proposed measures and implementation of rational schematic and engineering solutions for heat and hot water supply systems cam reduce the energy loss for heating and hot water by 30-35%. Originality. The paper for the first time proposed the use of new integrated approaches to maintain the desired heat balance in the winter period, as well as the new schematic solutions for heating and ventilation systems, both in winter and in summer, based on the use of heat pumps and secondary energy resources. Practical value. The introduction of the proposed schematic solutions and approaches demand relatively small capital investments and do not require significant reconstruction of already installed systems.Item Modeling of Temperature Fields in a Solid Heat Accumullators(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2016) Belimenko, Serhii S.; Ishchenko, Volodymyr O.; Gabrіnets, Volodymyr O.; Gabrinets, Vladimir A.EN: Purpose. Currently, one of the priorities of energy conservation is a cost savings for heating in commercial and residential buildings by the stored thermal energy during the night and its return in the daytime. Economic effect is achieved due to the difference in tariffs for the cost of electricity in the daytime and at night. One of the most common types of devices that allow accumulating and giving the resulting heat are solid heat accumulators. The main purpose of the work: 1) software development for the calculation of the temperature field of a flat solid heat accumulator, working due to the heat energy accumulation in the volume of thermal storage material without phase transition; 2) determination the temperature distribution in its volumes at convective heat transfer. Methodology. To achieve the study objectives a heat transfer theory and Laplace integral transform were used. On its base the problems of determining the temperature fields in the channels of heat accumulators, having different cross-sectional shapes were solved. Findings. Authors have developed the method of calculation and obtained solutions for the determination of temperature fields in channels of the solid heat accumulator in conditions of convective heat transfer. Temperature fields over length and thickness of channels were investigated. Experimental studies on physical models and industrial equipment were conducted. Originality. For the first time the technique of calculating the temperature field in the channels of different cross-section for the solid heat accumulator in the charging and discharging modes was proposed. The calculation results are confirmed by experimental research. Practical value. The proposed technique is used in the design of solid heat accumulators of different power as well as full-scale production of them was organized.Item Prediction of Atmosphere Pollution in Case of Emissions From Main Mine Fans(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaiev, Mykola M.; Bondarenko, Iryna O.; Rusakova, Tetiana I.; Shynkarenko, Viktor I.; Gabrіnets, Volodymyr O.ENG: Purpose. Emissions from mine ventilation system can create intensive atmosphere air pollution. As a rule, a huge amount of dust from mine fan enters atmosphere low layers. An important task is the development of methods to assess levels of the atmosphere pollution near mines and settlements. To solve this problem it is important to have physically proved mathematical models. Nowadays to predict the atmosphere pollution near settlements which are effected by mine fan the empirical model OND–86 is used. This model does not take into account many important physical factors. So, the purpose of this study is the development of quick computing mathematical model to predict the atmosphere pollution in case of dust emissions from mine fan. Methodology. To predict levels of the atmosphere pollution in case of mine fan work 3D equation of dust convective – diffusive flow was used. This equation takes into account gravity fallout, wind velocity, atmosphere turbulent diffusion, location of dust emission source. To sole modeling equation the implicit difference scheme of splitting was used. Findings. Developed mathematical model allows quick prediction of the level of atmosphere pollution in case of dust emissions from mine ventilation fan. The models allow to obtain zones of contamination near settlements which are situated in vicinity of mine. Originality. The developed mathematical model takes into account a number of physical factors, which at the present time are not considered on the days when prediction of the atmosphere pollution in settlements near mine is carried out. Practical value. On the basis of the developed mathematical model program code was created. This code can be used for evaluation of atmosphere pollution in settlements which are effected mine fan emissions.