Факультет технічних систем і енергоефективних технологій (ТеСЕТ)
Permanent URI for this communityhttps://devessuir.sumdu.edu.ua/handle/123456789/25
Browse
5 results
Search Results
Item Increasing fretting resistance of flexible element pack for rotary machine flexible coupling Part 1. Analysis of the reasons affecting fretting resistance of flexible elements for expansion couplings(IOP Publishing Ltd, 2021) Tarelnyk, V.; Hlushkova, D.; Martsynkovskyy, V.; Dumanchuk, M.; Antoszewski, B.; Kundera, Cz.; Konoplianchenko, Ie; Tarelnyk, N.; Гудков, Сергій Миколайович; Hudkov, Serhii Mykolaiovych; Загорулько, Андрій Васильович; Zahorulko, Andrii VasylovychIt has been made an analysis of the rotor machine flexible coupling (FC) failure reasons. As a result, it has been found out that the flexible coupling trouble-free operation period is limited by the pack of the flexible elements (FE) durability which depends on the fretting resistance of the individual flexible elements (plates) of the pack. The investigations with the use of an electron microscope have proved that there are at least three stages of the FE destruction: the formation of microfractures in the form of caverns at separate points of the FE destruction zone, which microfractures preserve microparticles of the destroyed metal in a confined space; weakening of the compression force affecting the plates and the wear product release from the fracture site; occurrence of abrasive wear resulting in the complete destruction of the FE. There has been substantiated the need in performing the FE stress-strain state analysis and determining the geometric and strain parameters of the strain zone, which can serve as a reserve for increasing the FE fretting resistance.Item Dynamics of impulse seals with tubular feeders(Journal of Physics: Conference Series, 2021) Марцинковський, Володимир Альбінович; Martsynkovskyi, Volodymyr Albinovych; Гудков, Сергій Миколайович; Hudkov, Serhii Mykolaiovych; Загорулько, Андрій Васильович; Zahorulko, Andrii Vasylovych; Kundera, Cz.The paper presents a technique for calculating forced axial oscillations and stability of impulse seals with tubular feeders. Unlike the existing methods of calculation, wherein, for the sake of simplicity, the influence of the feeder conductance is neglected, this article describes a conductance effect on the dynamic characteristics of the impulse face seal. The proposed calculation technique makes it possible to determine amplitudes of forced oscillations of the axially movable bushing and stability limit for the geometric parameters chosen in the static calculation. As an example, the authors described a calculation of the impulse face seal of the rotor of the main Reactor Coolant Pump (RCP 20000-100). The amplitude and phasefrequency characteristics for different values of the nominal gap are constructed.Item New flowing system in cooling system axial-flow pump in a hard coal electric power plant(Journal of Physics: Conference Series, 2021) Peczkis, G.; Synowiec, T.; Загорулько, Андрій Васильович; Zahorulko, Andrii VasylovychThis article presents the new construction of a centrifugal impeller pump which supplies the cooling system in coal power plants. The article also shows the history of producing this kind if pumps for unified 125 MW and 200 MW power units which dominate in Poland. The process of numerical analysis and conventional calculations leading to the improvement of qualities of the flowing system exceeding literature indicators are presented. The article shows the problems which appeared during assembling the pump in its target workplace. The results of the measurements of the pump flowing system in its target workplace are presented.Item Experimental and Numerical Studies on the Influence of Blade Number in a Small Water Turbine(MDPI, 2021) Peczkis, G.; Wi´sniewski, P.; Загорулько, Андрій Васильович; Zahorulko, Andrii VasylovychThis paper demonstrates the procedure of blade adjustment in a Kaplan-type water turbine, based on calculations of the flow system. The geometrical adjustment of a twisted blade with varying chord length is described in the study. Computational fluid dynamics (CFD) analysis was used to characterise aerofoil and turbine performance. Furthermore, two turbines, with a different number of blades, were designed, manufactured, and tested experimentally. The numerical model results were then compared with the experimental data. The studies were carried out with different rotational velocities and different stator blade incidence angles. The paper shows a comparison of the turbine efficiencies that were assessed, using numerical and experimental methods, of a flow system with four- and five-bladed rotors. The numerical model results matched up well with those of the experimental study. The efficiency of the proposed turbines reached up to 72% and 84% for fourbladed and five-bladed designs, respectively. These efficiencies, when considered with the turbine’s simplicity, low production and maintenance costs, as well as their potential for harvesting energy from low energy flows, mean that Kaplan turbines provide a promising technology for processing renewable energy.Item Calculation of the Characteristics of the Multi-gap Seal of the Centrifugal Pump, in Dependence on the Chambers’ Sizes(Manufacturing Technology, 2020) Позовний, Олександр Олександрович; Позовный, Александр Александрович; Pozovnyi, Oleksandr Oleksandrovych; Загорулько, Андрій Васильович; Загорулько, Андрей Васильевич; Zahorulko, Andrii Vasylovych; Krmela, J.; Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem Yevhenovych; Krmelová, V.The paper presents the results of an experimental research and a numerical calculation of a multi-gap seal of a centrifugal pump. The experimental research allowed to obtain the characteristics’ performance of the multi-gap seal at different operating modes, in dependence on the axial size of the chambers, pressure distributions’ changes, and a leakage from the seal. Using finite volume methods, values of radial hydrostatic forces, pressure distributions and leakage values were obtained. The results of the numerical calculation were compared with the results of the experiment, which showed that they matched.