Видання зареєстровані авторами шляхом самоархівування
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Item Combined operating process of torque flow pump(IOP Publishing Ltd, 2021) Панченко, Віталій Олександрович; Panchenko, Vitalii Oleksandrovych; Герман, Віктор Федорович; Herman, Viktor Fedorovych; Кондусь, Владислав Юрійович; Kondus, Vladyslav Yuriiovych; Івченко, Олександр Володимирович; Ivchenko, Oleksandr Volodymyrovych; Ryasnaya, O.Due to a simple design and hydraulic passage that is the least susceptible to clogging, torque flow pumps (TFP) of Turo type are the most common pumps used for pumping various hydraulic mixtures. These pumps are referred to vortex pumps, operation of which is accompanied by energy loss and vortex formation resulting in low economic efficiency. Since the TFP is a vortex hydraulic machine, the ratio of the fluid velocity in the free pump passage to the impeller rotational speed ωfluid/ω is an indicator of the TFP efficiency. The higher the value of ωfluid, the more efficient the pump is. The mechanism of the energy transfer in the TFP is caused by both blade and vortex operating process, or a combined operating process. The efficiency of the pump can be improved by increasing the portion of blade operating process. The aim of the study is to improve the efficiency of the TFP of Turo type by modifying the impeller design, to obtain a basic equation of the TFP with a new impeller which has several extended blades, and to study the influence of the impeller geometry on the pump performance experimentally. The study was carried out by analytical and experimental methods. The equation describing the head dependence on the hydraulic passage dimensions of the pump with a new impeller was obtained analytically. This equation can be used to clarify the methodological recommendations for designing the pump. The energy balance in the TFP was analyzed. During the testing on a test rig, the characteristics of the pump were obtained, which confirmed the advantages of using the modified impeller with extended blades resulting in increase of the portion of the blade operating process.Item Improving the efficiency of condensation installations of steam turbines by applying liquid-vapor ejector(РС ТЕСHNOLOGY СЕNTЕR, 2022) Шарапов, Сергій Олегович; Шарапов, Сергей Олегович; Sharapov, Serhii Olehovych; Євтушенко, Святослав Олександрович; Евтушенко, Святослав Александрович; Yevtushenko, Sviatoslav Oleksandrovych; Панченко, Віталій Олександрович; Панченко, Виталий Александрович; Panchenko, Vitalii Oleksandrovych; Козін, Віктор Миколайович; Козин, Виктор Николаевич; Kozin, Viktor Mykolaiovych; Івченко, Олександр Володимирович; Ивченко, Александр Владимирович; Ivchenko, Oleksandr VolodymyrovychThis paper considers the possibility of using liquid-vapor ejectors in condensing units of steam turbines. This unit is designed for pumping out a steam-air mixture from a steam turbine condenser, in which the process occurs at a pressure lower than atmospheric. In the traditional scheme, this is provided by a two-stage steam-jet ejector unit. The proposed scheme involves the use of a single-stage liquid-vapor ejector and its possible pre-vacuum mode of operation in conjunction with a liquid-ring vacuum pump. A working process of the liquid-vapor ejector does not require the supply of working steam from the outside since its generation occurs in the active nozzle of the liquid-vapor ejector. A description of the traditional scheme and the proposed options is given, which are different both in the scheme solution and in the operating parameters. The object of this study is a liquid-vapor ejector, which is used in the condensing system of a steam turbine. Thermodynamic calculation of the proposed circuit solutions was carried out. As a result, the necessary mode parameters of the schemes were determined. To assess the feasibility of using a liquid-vapor ejector in the condensation systems of steam turbines, an exergy analysis was performed. The proposed scheme makes it possible to increase efficiency by 2.3 times, and when used with a liquid-ring vacuum pump – by 2.44 times. To assess the economic efficiency of the modernization of the condensing system, thermoeconomic analysis was performed. The use of the proposed scheme makes it possible to reduce the cost of generating boiler steam and reduce the cost of the resulting product of the steam turbine unit by about 51 %. The estimated cost of a unit of the amount of boiler steam consumed per ton of product and the unit cost of steam were established.Item Method for an Effective Selection of Tools and Cutting Conditions during Precise Turning of Non-Alloy Quality Steel C45(MDPI, 2022) Івченко, Олександр Володимирович; Ивченко, Александр Владимирович; Ivchenko, Oleksandr Volodymyrovych; Іванов, Віталій Олександрович; Иванов, Виталий Александрович; Ivanov, Vitalii Oleksandrovych; Trojanowska, J.; Жигилій, Дмитро Олексійович; Жигилий, Дмитрий Алексеевич; Zhyhylii, Dmytro Oleksiiovych; Ciszak, O.; Залога, Ольга Олександрівна; Залога, Ольга Александровна; Zaloha, Olha Oleksandrivna; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Гладишев, Дмитро Павлович; Гладышев, Дмитрий Павлович; Hladyshev, Dmytro PavlovychThe paper presents a constructing methodology for a modern approach to tools selection and solving the problem of assigning optimal cutting parameters for specific production conditions. The mathematical formulation determining the extreme values of the technological process optimality criteria is obtained. A system of technical and economic quality indicators for cutting tools is proposed. This system allows principles’ implementation of decentralization and interoperability “Industry 4.0” via finite element modeling of the cutting process based on solving the problem of orthogonal free cutting modeling. The proposed methodology further usage is possible by creating a standardized database on the parameters of the tool: the adhesive component of the friction cutting coefficient for processing of a specific pair of cutting and tool materials (or tool coating material) and the impacts of the cutting-edge radius on cutting efficiency of a particular material.