Факультет технічних систем і енергоефективних технологій (ТеСЕТ)
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Item Special Issue on Modelling, Simulation and Control in Combustion Processes of Renewable Fuels(MDPI, 2022) Pitel, J.; Hrdlička, J.; Павленко, Іван Володимирович; Pavlenko, Ivan VolodymyrovychThe modeling and simulation of combustion processes is still a challenging field. It requires integrating heat and mass transfers, flow conditions, and reaction chemistries. The available tools for such modeling methods are very different and are usually problem-specific. One particular field of interest is the fluidized bed combustion of solid fuels, which additionally encounters fluidized bed hydrodynamics and particle interactions. Recent trends in the field focus on a more detailed description and understanding of the burn-out mechanism of solid fuel particles, which is essential for modeling in order to produce reasonable outputs. From a control point of view, for example, the dynamic models of combustion processes are essential in model-based control algorithms. Due to their complexity, dynamic modeling based on partial differential equations and parameter identification for the corresponding transient models is a topical problem that can be solved using a comprehensive approach based on experimental data, numerical simulation, regression modeling, and artificial intelligence methods. One common challenge is validating the models in an actual process, which requires in-depth and precise measurements that are typically complicated by limited access to the combustion process zone. This information is also essential for controlling and monitoring combustion processes.Item Vapor Overproduction Condition Monitoring in a Liquid–Vapor Ejector(MDPI, 2022) Шарапов, Сергій Олегович; Sharapov, Serhii Olehovych; Mižáková, Ja.; Гусєв, Данило Максимович; Husiev, Danylo Maksymovych; Панченко, Віталій Олександрович; Panchenko, Vitalii Oleksandrovych; Іванов, Віталій Олександрович; Ivanov, Vitalii Oleksandrovych; Павленко, Іван Володимирович; Pavlenko, Ivan Volodymyrovych; Židek, K.We consider the influence of vapor content in the mixed flow leaving a liquid-vapor ejector on the energy efficiency of a vacuum unit. As shown by numerical studies of liquid-vapor ejectors, this issue is important as vapor overproduction, which accompanies the process of secondary flow ejection, directly impacts the efficiency of the working process of both the liquid-vapor ejector and the vacuum unit as a whole. The greater the degree of vapor overproduction, the greater the load on the vapor phase of the separator, which is part of the vacuum unit. In addition, the liquid phase must be returned to the cycle to ensure the constancy of the mass flow rate of the working fluid of the primary flow. Our numerical study results revealed the rational value of the degree of vapor overproduction at which the efficiency of the liquid–vapor ejector was maximized, and the amount of additional working fluid that needed to enter the cycle of the vacuum unit was minimal. Experimental condition monitoring studies on the liquid–vapor ejector were carried out on plane-parallel transparent models with different flow path geometries. Through experimental studies, we confirmed and adjusted the values of the achievable efficiency of the working process of a liquid–vapor ejector, depending on the degree of vapor overproduction. Using a comparative analysis of liquid–vapor ejectors with different flow path geometries, differences were revealed in their working processes, which consisted of the degree of completion of the mixing of the working media of primary and secondary flows. To determine the feasibility of using liquid–vapor ejectors with different flow path geometries, exergy analysis was performed, resulting in achievable efficiency indicators.Item Application of the CFD software for modeling thermal comfort in sport hall(MM Science Journal, 2020) Rimar, M.; Kulikov, A.; Fedak, M.; Хованський, Сергій Олександрович; Khovanskyi, Serhii Oleksandrovych; Павленко, Іван Володимирович; Pavlenko, Ivan VolodymyrovychThe building as a single energy system represents not just a set of elements of fencing structures and engineering equipment, but a certain combination of them. The object under the study was the sports hall. During the simulation, the calculation model of energy, viscous and radiation was chosen. A comparison of thermal conditions of the premises with different heating methods confirmed that direct heating of the halls is a more appropriate form comparing to the radiator heating. The developed models allow to carry out an estimation of observance of comfortable conditions in the premises, to carry out the analysis of the thermal balance of the premises.Item 3D Modeling of a Virtual Built Environment Using Digital Tools: Kilburun Fortress Case Study(MDPI, 2023) Tytarenko, I.; Павленко, Іван Володимирович; Pavlenko, Ivan Volodymyrovych; Dreval, I.The reliable reconstruction of cultural or historical heritage objects is an urgent problem for humanity. It can be successfully solved using up-to-date 3D modeling tools. The proposed technique allows for modeling virtual environments at an even higher level. This study aimed to develop an approach for designing historical heritage objects with sufficient accuracy using a built environment. The Kilburun Fortress was chosen as the object of study. The modeling procedure includes monitoring the object’s territory, analyzing archival, librarian, and cartographic sources, and further modeling and reproducing the research object in a virtual environment using various software tools. The following stages were implemented during this study: analysis and processing of preliminary data (analysis of plans and schemes, overlapping maps); the scaling of graphical objects for the reliable reproduction of the studied object; the design of a working 3D model using AutoCAD and SketchUp; the rendering and final processing of textures using Quixel; and visualization using Twinmotion. As a result, a model of the historical heritage object was created using 3D means. The model can also be integrated into ArchiCAD and Revit software.Item Parameter Identification of the Fractional-Order Mathematical Model for Convective Mass Transfer in a Porous Medium(MDPI Publishing, 2023) Павленко, Іван Володимирович; Pavlenko, Ivan Volodymyrovych; Ochowiak, M.; Włodarczak, S.; Krupinska, A.; Matuszak, M.Fractional calculus is an essential tool in studying new phenomena in hydromechanics and heat and mass transfer, particularly anomalous hydromechanical advection–dispersion considering the fractal nature of the porous medium. They are valuable in solving the urgent problem of convective mass transfer in a porous medium (e.g., membranes, filters, nozzles, convective coolers, vibrational prillers, and so on). Its solution allows for improving chemical engineering and technology workflows, refining process models for obtaining porous granular materials, realizing the convective cooling of granular and grain materials, and ensuring the corresponding apparatuses’ environmental safety. The article aims to develop a reliable convective mass transfer model for a porous medium and proposes a practical approach for its parameter identification. As a result, a general scientific and methodological approach to parameter identification of the fractional convective mass transfer model in a porous medium was proposed based on available experimental data. It mainly used Riemann–Liouville fractional time and coordinate derivatives. The comprehensive application of the Laplace obtained the corresponding general solution transform with respect to time and a coordinate, the Mittag-Leffler function, and specialized functions. Different partial solutions in various application case studies proved this solution. Moreover, the algorithm for practically implementing the developed approach was proposed to evaluate parameters for the considered model by evaluation data. It was reduced to the two-parameter model and justified by the available experimental data.Item An Increase in the Energy Efficiency of R744 Heat-Using Thermotransformers(MDPI, 2023) Арсеньєв, В`ячеслав Михайлович; Arseniev, Viacheslav Mykhailovych; Piteľ, J.; Король, Олександр Сергійович; Korol, Oleksandr Serhiiovych; Шарапов, Сергій Олегович; Sharapov, Serhii Olehovych; Mižáková, J.; Павленко, Іван Володимирович; Pavlenko, Ivan Volodymyrovych; Іванов, Віталій Олександрович; Ivanov, Vitalii OleksandrovychThis article deals with improving waste heat transformation in heat-using thermotransformers. Based on the directives of the European Commission on refrigeration equipment requirements, the possibility of using carbon dioxide (R744) in heat-using thermotransformers was evaluated. The possibility of the effective use of heat-using thermotransformers operating within the Chistyakov–Plotnikov cycle in the heat pump mode was assessed. As a result, a comparative analysis was performed with existing modern plants for combined cycles with an expander, for the expansion of CO2 in saturated steam, a suction gas heat exchanger (SGHE), and a compressor–expander unit. The design schemes with a throttling device and an SGHE were selected for a comparative analysis. As a result, calculation models for evaluating the operating parameters for the initial and proposed design schemes were developed. These models allow for evaluating thermodynamic and mode parameters for heat-reducing thermotransformers. They also allow for ensuring energy efficiency indicators and conversion factors for each cycle. Overall, the dependencies for the cycle conversion ratio for the pressure increase stage in the compressor were obtained for various under-recovery rates. Moreover, the cycle conversion ratios for the proposed design schemes were obtained depending on the discharge pressure of the first compressor. The proposed design schemes allow for increasing the energy efficiency of heat-using thermotransformers by an average of 23%, depending on the suction pressure in the compressor.Item Experimental Studies and Condition Monitoring of Auxiliary Processes in the Production of Al2O3 by Sol–Gel Technology(MDPI, 2022) Склабінський, Всеволод Іванович; Склабинский, Всеволод Иванович; Sklabinskyi, Vsevolod Ivanovych; Ляпощенко, Олександр Олександрович; Ляпощенко, Александр Александрович; Liaposhchenko, Oleksandr Oleksandrovych; Piteľ, J.; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Скиданенко, Максим Сергійович; Скиданенко, Максим Сергеевич; Skydanenko, Maksym Serhiiovych; Острога, Руслан Олексійович; Острога, Руслан Алексеевич; Ostroha, Ruslan Oleksiiovych; Юхименко, Микола Петрович; Юхименко, Николай Петрович; Yukhymenko, Mykola Petrovych; Simeiko, K.; Demianenko, M.; Volf, M.; Starynskyi, O.; Юрченко, Олександр Юрійович; Юрченко, Александр Юрьевич; Yurchenko, Oleksandr Yuriiovych; Мандрика, О.Powders and granules of heavy metal oxides produced through condition monitoring are in high demand as intermediate products for obtaining fine-grained ceramics for a wide range of applications, i.e., nuclear fuel and fuel elements for nuclear power plants. Sol–gel technology to produce nuclear fuel (UO2), as well as catalysts (ThO2) for organic synthesis in the form of granules from pressed microspheres, is a promising method to obtain powders and granules of heavy metal oxides (fine-graded ceramics). Al2O3 was selected as the model analog at the stages of obtaining a solution of heavy metal and sol, the formation and gelation of droplets, and the preparation of gel spheres and their further washing and drying, as well as recovery and firing of particles. In the study, the main parameters were substantiated, e.g., the diameter and angle of inclination of the axis for the holes in the perforated shell, the multiplicity of sol circulation before the holes, the coefficients of liquid (sol) flow rate, the oscillation frequency of the disperser, and the concentration of surfactant and acid in sol. All of these parameters affect the characteristics of the granules that are obtained by sol–gel technology. Moreover, recommendations to increase productivity and the energy efficiency of production were also given. In particular, it was found that oscillation frequency in a range of 70–80 Hz leads to a granulometric composition of the obtained granules of 2.0–2.2 mm. A hole of 0.85 mm and a frequency of 100 Hz slightly change this range to 1.2–2.0 mm, while maintaining monodispersity.Item The D2-Law of Droplet Evaporation When Calculating the Droplet Evaporation Process of Liquid Containing Solid State Catalyst Particles(MDPI, 2022) Ochowiak, M.; Bielecki, Z.; Bielecki, M.; Włodarczak, S.; Krupińska, A.; Matuszak, M.; Choiński, D.; Lewtak, R.; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan VolodymyrovychThe review presents the D2-law of droplet evaporation, which is used to describe the spraying process involving the evaporation of droplets. This law, the subject of numerous publications, can be successfully applied to describe the droplet evaporation process under various conditions, including the calculations of the process of feeding the boiler with a liquid that contains catalyst particles. To date, not a lot of work has been devoted to this issue. The paper is a continuation of previous research concerning the spraying of liquids with a catalyst, which improves the efficiency of the process. The conducted analysis showed that the experimental data from previously published work are very compatible with the data obtained from the D2-law of droplet evaporation. At the standard speed of about 20 m/s of an aerosol flowing through a dust duct, droplets in the stream should be observed up to a distance of 1 m from the outlet of the apparatus supplying the system. Under such flow conditions, a droplet’s lifetime must be above 0.05 s. The dependence between a droplet’s lifetime and its diameter and temperature was determined. The obtained results confirmed that the effective droplet diameter is above 30 µm. Such droplets must be generated and then fed to the boiler for the catalyst to work properly. This law is an engineering approach to the problem, which uses relatively simple model equations in order to determine the evaporation time of a droplet.Item Development of Flexible Fixtures with Incomplete Locating: Connecting Rods Machining Case Study(MDPI, 2022) Іванов, Віталій Олександрович; Иванов, Виталий Александрович; Ivanov, Vitalii Oleksandrovych; Botko, F.; Dehtiarov, I.; Kočiško, M.; Evtuhov, A.; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Trojanowska, J.The rapid development of manufacturing in recent years has led to a significant expansion of the technological capabilities of modern metal-cutting equipment. Therefore, the modern approach to intensifying production requires an advanced fixture design. Design and manufacture of flexible fixtures capable of machining similar shapes and sizes of complex geometry parts reduce setup time. The article aims to design flexible fixtures for parts such as one-piece connecting rods under incomplete locating conditions. The advantages are the minimum number of parts and tool availability for multi-axis machining connecting rods in one setup. This approach, combined with up-to-date machining centers and industrial robots, can increase the production efficiency of manufacturing non-removable connecting rods. This effectiveness is in a decrease in the number of operations by 5–7 times, fixtures—by 3–4 times, and machine tools—by 3–5 times, depending on the type of a non-removable connecting rod and its design features. The numerical simulation results of the proposed fixture design confirmed the comprehensive technological capabilities and dynamic characteristics. Particularly, a decrease in displacements and oscillation amplitudes up to 7% compared to the full-basing locating chart was provided. It is determined that the system “fixture–workpiece” entirely meets all the strength, accuracy, and rigidity parameters, which allows you to perform machining with intensive cutting modes. The amplitudes of oscillations do not exceed the tolerances on the dimensions of these surfaces, established by requirements for non-removable connecting rods, and all displacements are elastic. During numerical simulation, the workpiece position remained stable at all machining steps.Item Classification of Separation Equipment by Design and Technological Features(European Alliance for Innovation, 2022) Іванов, Віталій Олександрович; Иванов, Виталий Александрович; Ivanov, Vitalii Oleksandrovych; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Caganova, D.; Ляпощенко, Олександр Олександрович; Ляпощенко, Александр Александрович; Liaposhchenko, Oleksandr Oleksandrovych; Дем`яненко, Марина Миколаївна; Демьяненко, Марина Николаевна; Demianenko, Maryna Mykolaivna; Лобов, Євгеній Сергійович; Лобов, Евгений Сергеевич; Lobov, Yevhenii Serhiiovych; Golokhvost, O.Production range increasing causes many obstacles to ensure the work of the chemical industry. Production must respond quickly to the slightest change and must be customer-oriented. Due to this, there is a general trend towards increasing production flexibility by introducing modular systems. Thus, there is a need to classify existing solutions to develop flexible systems based on them. The article contains the analysis of chemical industry development tendencies, a methodology of research of modular separation devices, and their classification by design and technological features. The study result is a design and technological classification with a code that can optimize various separation devices. As a result of experimental research, preliminary and acceptance tests of experimental samples, the main hydrodynamic and separation characteristics of modular separation devices and combined multifunctional separators are determined: hydraulic resistance 0.15–2.00 kPa for units and 15–30 kPa for devices; effective capture of particles from the size of 5 μm; efficiency of separate stages of modular separation devices is about 70–90 %; efficiency of combined multifunctional separators is approximately 99.5–99.9 %. The offered multipurpose separators equipped with dynamically regulated modular separation devices do not concede to world analogs by the main technical characteristics of combined multistage separators worldwide.