Journal of Engineering Sciences / Журнал інженерних наук
Permanent URI for this collectionhttps://devessuir.sumdu.edu.ua/handle/123456789/34326
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Item Development of energy enterprises in the context of green transformation(Sumy State University, 2023) Plotkin, J.; Levchenko, N.; Shyshkanova, G.; Levchenko, S.The article argues that the search for effective tools to ensure the economically secure future of energy companies and their development in the context of green transformation is necessary due to the speed of global transformations, the priority of reducing dependence on fuel and energy imports, the development of renewable energy sources, the instability of the environment for the functioning of energy companies (as a result of russia’s fullscale invasion of Ukraine) and their position both on the Ukrainian and European energy markets. The reality of the energy sector in the country and the steps for the recovery of the energy companies determined by the Economic Recovery Plan of Ukraine were analyzed. The evidence shows that the legislative amendments aimed at stabilizing the energy sector and solving key issues lack efficiency and cannot ensure the vital activity of energy enterprises and their development in the conditions of climate-neutral transformation. A methodology was proposed to assess the progress of the carbon-neutral development of energy companies, which should become the basis for attracting ESG investing. The vectors for creating a favorable environment for environmental, social, and governance (ESG) investing were identified as a unique opportunity to ensure the economically secure future of energy companies and their development in the context of green transformation.Item Optimization of greenhouse microclimate parameters considering the impact of CO2 and light(Sumy State University, 2023) Соколов, Сергій Вікторович; Соколов, Сергей Викторович; Sokolov, Serhii ViktorovychThe most critical parameters of the microclimate in greenhouses are air and soil temperature, air and soil moisture, plant illumination, and carbon dioxide (CO2) concentration in photosynthesis. New energy sources and resource-efficient management of microclimate parameters in greenhouses can be utilized to reduce greenhouse crop cultivation costs and increase profits. As the plant mass increase depends on photosynthesis, which involves the formation of glucose in the plant chloroplasts from water and carbon dioxide under the influence of light radiation, the saturation of greenhouses with carbon dioxide has become popular in recent decades. However, insufficient light slows down the process of glucose formation, while excessive light intensity negatively affects photosynthesis. Based on the experimentally proven Van Henten model of plant growth and using the MATLAB environment, a methodology was proposed, and the dependence between CO2 concentration and leaf lettuce illumination power required for maximum photosynthesis was determined. It is equal to 0.57 ppm/(W/m2 ). Such dependence should be considered when designing control systems to reduce resource and energy costs for greenhouse crop cultivation while ensuring maximum yield.Item A scheduling model in capturing methane gas from methane clathrates deposits(Sumy State University, 2023) Anyanwu, U.O.; Okafor, O.C.; Nkwor, C.A.The execution of any project type, especially engineering-based projects, is usually time-based, efficiency-driven, and cost-effective. These factors are the deterministic parameters that engineer successful project completion. The application of scheduling models remains the best technique for achieving these three factors to their best degrees. Therefore, this study was centered on the impact study of applying the scheduling model in harvesting methane gas from methane clathrates deposits. Various data on gas hydrate reserves in the Niger Delta region of Nigeria were collected from relevant literature, studied, and analyzed. Such data includes the pictorial representation and description of the gas hydrate site in the Niger Delta region of Africa and various shapes and sizes of gas hydrate perimeters in the studied region positions of the gas reserves. The normal faults are projected on a bathymetric map of the study area and the bathymetric map of the Pockmark (with the stippled black line indicating the sea floor projection of a prominent N-S trending fracture in 3-D seismic data). As a type of scheduling model, the critical path method (CPM) was applied to develop the project’s work sequence using the activity on node (AON) architectural technique and Primavera P6 software after carefully identifying the primary operations involved in the project and their respective sub-operations or work breakdown structure (WBS). The risks associated with each operation were meticulously identified, with their consequent impact and exposure matrix determined using probabilistic measures of 1-5 according to the degree of the risk. Mitigation strategies were recommended for all the identified risks. The cost benefits of the project were X-rayed using parameters such as net present value (NPV), project payback time, internal rate of return (IRR), and net cumulative cash flow. From the results obtained, the CPM schedule showed that the project execution would last approximately ten months. All the operations involved in the project execution plan were all critical, proving that each activity should be completed within the scheduled run period. Else, the entire project would be affected. Also, risks with a high exposure matrix of 25, 12, and 4 were mitigated to 5, 3, and 0 using the recommended strategies. In addition, the project yielded an NPV of $20,736,951.04 for the run period of 22 years after the execution of the project, IRR of 14 %, and a payback time of 8 years (adding 2023- the year of project execution) provided the daily production rate is maintained within 60,000-65,000 MSCF/day. The cash flow and payback time will decrease if the daily production rate increases. Therefore, the application of CPM in extracting methane gas from gas hydrates positively affected the operation through the vivid insights provided in workflow pattern/methodology risks effects and cost benefits.Item Regeneration of chromate galvanic solutions in membrane electrochemical devices(Sumy State University, 2022) Сердюк, Василь Олексійович; Сердюк, Василий Алексеевич; Serdyuk, Vasil OleksIyovich; Склабінський, Всеволод Іванович; Склабинский, Всеволод Иванович; Sklabinskyi, Vsevolod Ivanovych; Большаніна, Світлана Борисівна; Большанина, Светлана Борисовна; Bolshanina, Svitlana Borysivna; Ochowiak, M.; Radchenko, A.; Babenko, O.; Kharchenko, Y.The regeneration processes of industry technological passivating baths of electrochemical cadmium lines and electrochemical galvanizing lines as an applied result of two-chamber membrane cation-exchange electrochemical devices researched. Actual industrial passivation baths of cadmium and zinc galvanic coatings applied as anode chambers. The cathode chamber contained sulfuric acid 1 % solution and a titanium cathode (BT-0). A window was cut in one of the walls with a RALEX®CM-PES 11-66 cation exchange membrane placed in it. The lead (С-0) was used as the anode. A comparative analysis of the performance of these technological baths before and after the using cation exchange membrane electrochemical devices was carried out. As a result of long-term experimental studies, the ecological and economic feasibility of their use was proven.Item Determination of a suitable retrofit of R-134A using refrigerant blends of R290 and R600 aided by an optimization technique(Sumy State University, 2022) Anaemeje, J.C.; Owuama, K.C.; Okafor, O.C.; Madu, K.EThe effect of the hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants on the environment through the attack of its halogen contents-chlorine and fluorine, on the ozone layer and the toxic nature of such refrigerants, has paid the attention of researchers to work towards getting suitable alternatives using hydrocarbons (HC) or its blends with HFC refrigerants. This study was centered on getting a suitable retrofit of R134A with a good coefficient of performance (COP) and low global warming potential (GWP) using the blends of R290 and R-600 HCs for use in refrigeration systems. An experimental testing rig was developed by assembling various measuring devices to the operational points of a vapor compression refrigerator. A mixture design was developed using the simplex lattice design (SLD) of design expert software 11.0. The response variables considered were COP and GWP. The experimental design was meticulously followed using 1kg for each refrigerant run, and the temperature and pressure values at the operating points were noted. From the results obtained, blend A had the highest COP of 2.5 and the highest GWP value of 3.93. Blend D had the lowest value of C.O.P. of 1.33, while blend B had the lowest value of GWP of 3.51. Also, the optimal blend was achieved at a mixture factor of 59% R-290a and 41% R-600. The response values obtained at this optimal mixture level were COP-2.05182 and GWP – 3.59. Therefore, the optimal blend obtained would be a better retrofit to R-134a and could be used in refrigeration systems.Item Ways for improvement of reverse axial pumps(Sumy State University, 2022) Мандрика, Анатолій Семенович; Мандрыка, Анатолий Семенович; Mandryka, Anatolii Semenovych; Majid, A.P.; Ратушний, Олександр Валерійович; Ратушный, Александр Валерьевич; Ratushnyi, Oleksandr Valeriiovych; Куліков, Олександр Андрійович; Куликов, Александр Андреевич; Kulikov, Oleksandr Andriiovych; Сухоставець, Дар'я Ігорівна; Сухоставец, Дарья Игоревна; Sukhostavets, Daria IhorivnaThe article is devoted to a pilot study of the reverse-bladed pump. The characteristics of the reverse bladed pump are the identical parameters on flow, the head, power, energy efficiency on direct and the return operating modes (at rotation of a rotor of the pump both in one and to the opposite side). The model reversible axial pump with two impeller versions was tested on an experimental bench. The impellers were distinguished by the shape of the profile in the blade sections. The model reversible pump was structurally a reversible axial impeller placed in a cylindrical chamber. Studies were carried out at different angles of rotation of the impeller blades. The power characteristics of tested versions of the pump (impeller) at the design and under loading (unstable operation) modes are given. Low efficiency of the tested versions of the reversible pump compared to the conventional axial pumps is noted, primarily due to the strong influence of the secondary gradients of the pressure factor. The second reason is the profile separation of the flow from the blade surface, to which the tested reverse pump screens are predisposed.Item Impact of the closed, semi-opened, and combined contra-rotating stages on volume loss characteristics(Sumy State University, 2022) Куліков, Олександр Андрійович; Куликов, Александр Андреевич; Kulikov, Oleksandr Andriiovych; Ратушний, Олександр Валерійович; Ратушный, Александр Валерьевич; Ratushnyi, Oleksandr Valeriiovych; Moloshnyi, O.; Івченко, Олександр Володимирович; Ивченко, Александр Владимирович; Ivchenko, Oleksandr Volodymyrovych; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan VolodymyrovychThe article is devoted to studying the contra-rotating stages with different impellers and blade discs. Determining the reduction of volumetric losses by modeling the contra-rotating stages in the software package ANSYS CFX. The work aimed to create and study the flow and characteristics: semi-open, closed impellers, and blade discs. As a result of the work, the following contra-rotating stages were determined and compared: the semiopened impeller with the semi-opened blade disc; the closed impeller with the closed blade disc; the semi-opened impeller with the closed blade disc; the closed impeller with the semi-opened blade disc. As a result of research, fluid flows in contra-rotating stages and their characteristics in the form of pressure and efficiency were obtained. According to the obtained data, the expediency of using contra-rotating stages as a working body of the pump is written.Item Rational choice of a basket for the rotational vibropriller(Sumy State University, 2022) Юрченко, Олександр Юрійович; Юрченко, Александр Юрьевич; Yurchenko, Oleksandr Yuriiovych; Склабінський, Всеволод Іванович; Склабинский, Всеволод Иванович; Sklabinskyi, Vsevolod Ivanovych; Ochowiak, M.; Острога, Руслан Олексійович; Острога, Руслан Алексеевич; Ostroha, Ruslan Oleksiiovych; Гусак, Олександр Григорович; Гусак, Александр Григорьевич; Husak, Oleksandr HryhorovychThe use of processing units for the production of mineral fertilizers in the industry in today’s market requires improved product quality and increased productivity. As a result, there is a need to change the design of existing units or some structural elements. Rotary vibroprillers, having a relatively simple design, can be of different designs that directly affect the productivity indicators mentioned above. The study considers the influence of the shape of the basket bottom on the quality of the rotational vibroprillers. After using the governing equation of prills motion in the airflow, a program was developed for automatic control of the rotational speed of the priller based on changes in melt loads. It is established that the size of the spray swath can be changed by varying the rotational speed of the priller. There is a tendency to affect the vibropriller performance by controlling the rotational speed and shape of the basket bottom without performance degradation.Item Adsorption of crystal violet on rice husk activated carbon(Sumy State University, 2022) Salahudeen, N.; Alhassan, A.The need to develop effective technology for the treatment of liquid effluent of dye-intensive industries such as textile, rubber, paint, and printing is synonymous with the need to save the life-threatening risks posed by these carcinogenic and mutagenic pollutants on human and aquatic lives. Isotherms of adsorption of crystal violet (CV) on activated carbon (AC) synthesized from rice husk are presented herewith to elucidate the mechanism of the adsorption process of crystal violet dye contaminated water on rice husk activated carbon. AC was synthesized from rice husk via a phosphoric acid activating agent at low temperatures. Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (DR) isotherm studies were employed. The mean square values for Langmuir, Freundlich, Temkin and D-R models were 0.98, 0.91, 0.94, and 0.63, respectively. Analysis of the isotherms of the adsorption of crystal violet sorbate on the synthesized rice husk sorbent suggested that the adsorption process proceeded via a homogeneous monolayer mechanism. Langmuir isotherm gave the best fit of the adsorption process. Langmuir isotherm constant was –1.40 l/mg, and the equilibrium adsorption capacity was 13.53 mg/g.Item Thermodynamic performance of boehmite alumina nanoparticle shapes in the counterflow double pipe heat exchanger(Sumy State University, 2022) Nogueira, E.This work compares a theoretical model with a consolidated numerical model related to the thermodynamic performance of boehmite alumina nanoparticles in different formats in a counterflow double pipe heat exchanger. The shapes of the non-spherical nanoparticles under analysis are platelets, blades, cylindrical, and bricks. The second law of thermodynamics is applied to determine Nusselt number, pressure drop, thermal efficiency, thermal and viscous irreversibilities, Bejan number, and the out temperature of the hot fluid. The entropy generation rates associated with the temperature field and the viscous flow are graphical determined. The numerical model uses the k-ε turbulence model, which requires empirical factors to simulate turbulent viscosity and rate of generation of turbulent kinetic energy. Compatibility between the models was demonstrated. It was shown that the maximum absolute numerical error between the quantities Nusselt number, heat transfer rate, and pressure drop for established and specific conditions is less than 12.5 %.