Energy Systems Engineering / Enerji Sistemleri Mühendisliği
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Article Citation - WoS: 8Citation - Scopus: 6Effect of external electric field on fluidization of rodlike particles using CFD-DEM(American Chemical Society, 2024) Kazemi, Saman; Aali, Hamed; Larijani, Roxana Saghafian; Zarghami, Reza; Liu, Helei; Mostoufi, NavidGiven the significant impact of an external electric field on fluidized bed hydrodynamics and the practical importance of rodlike particles, this study examines the behavior of a fluidized bed containing rodlike particles under various external electric fields. Simulations were performed using a coupled computational fluid dynamics-discrete element method, and rodlike particles were generated using a multisphere approach aided by quaternions. The effect of different vertical and horizontal external electric fields on the orientation of particles was investigated. Also, the effect of particle size on their orientation in the presence of constant vertical and horizontal external electric fields was explored in this work. The results showed that increasing the electric field strength and reducing the size of rodlike particles lead to an increment in the tendency of particles to become oriented along the direction of the electric field. Moreover, the effect of the external electric field at various inlet gas velocities on the probability distribution of the porosity in the bed was studied. Finally, the effect of vertical and horizontal electric fields on the bubble diameter was examined. This study offers a deeper understanding of the fluidization of rodlike particles in the presence of an electric field, and its findings can be applied to design and optimize related processes.Article Citation - WoS: 17Citation - Scopus: 24A Gis-Based Fahp and Fedas Analysis Framework for Suitable Site Selection of a Hybrid Offshore Wind and Solar Power Plant(Elsevier B.V., 2023) Karipoğlu, Fatih; Ozturk, S.; Efe, B.This study presents a Geographic Information System (GIS) based suitable site selection methodology for a hybrid system that includes offshore wind and solar PV. The methodology utilizes open source databases about decision criteria and applies this data using GIS to determine suitable sites for offshore wind and solar PV systems. For the assessment of multi-criteria which affect the potential hybrid energy power plants and the determination of the best suitable areas, Fuzzy Analytical Hierarchy Process (FAHP) and Fuzzy Evaluation based on Distance Average Solution (FEDAS) are used in the study. Results show that technical criteria has the priority weight of 0.60 while the weight of social criteria is about 0.07. Among sub-criteria, the wind speed has the highest priority weight while distance to port and visibility are the highest criteria of priority weight under economic and social main criteria, respectively. Among the alternatives, Area 2 (A-2) is determined as the best alternative for hybrid offshore power plants in the study area. This proposed methodology can be utilized by decision-makers to determine the best suitable locations for hybrid offshore wind and solar PV systems at any location. This paper suggests a new approach integrating GIS, fuzzy setbased AHP and EDAS as a novelty. © 2023 International Energy InitiativeBook Part Citation - Scopus: 4Investigation of a New Methanol, Hydrogen, and Electricity Production System Based on Carbon Capture and Utilization(Springer, 2023) Khani, Leyla; Mohammadpourfard, MousaIt is well-known that clean energy transition requires low carbon emission. The increase in population, economic development, and human welfare demands has led to a rise in energy consumption, mainly supplied by fossil fuels. However, burning fossil fuels produces carbon dioxide, which is a greenhouse gas and a contributor to environmental problems. Therefore, carbon capture and conversion to different products have gained attention. On the other hand, combining two or more different thermodynamic systems for simultaneous production of various demands from one energy source looks reasonable. In this regard, a new trigeneration system is proposed to decrease atmospheric carbon dioxide emission and produce methanol, hydrogen, and power. A flue gas stream with a defined composition, solar energy, and atmospheric air are the system’s inlets. Then, mass, energy, and exergy balance equations are applied for each subsystem to investigate the system’s thermodynamic performance. Also, the effect of changing operating parameters on the performance of each subsystem is studied. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.Book Part Citation - Scopus: 1A New Stable Solar System for Electricity, Cooling, Heating, and Potable Water Production in Sunny Coastal Areas(Springer, 2023) Khani, Leyla; Mohammadpourfard, MousaNowadays, more attention is paid to provide clean energy products with low environmental pollution in a decentralized way. Many coastal rural areas suffer from freshwater and electricity scarcity, especially in hot weather condition. Meanwhile, these regions have a great access to intense solar radiation and seawater. Hence, it seems logical to use the available solar energy in those places to provide to necessities like power, heating, and cooling. A new solar cooling, power, heating, and freshwater production system is designed, evaluated, and optimized in this research. The proposed system is composed of several subsystems to generate each product with high efficiency and reliability. Solar energy is unavailable at night, so molten salt energy storage is used to establish the steady operation of the system. Then, the system is evaluated from thermodynamic and exergoeconomic viewpoints, and a parametric study is accomplished to study the effect on the system performance of key variables. In the end, the system is optimized to determine its best operating condition for different cases. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.Article Citation - WoS: 1Citation - Scopus: 1Energy and Exergy Analysis of a Geothermal Energy Sourced Hot-Air Drying System(Inderscience Enterprises, 2023) Helvacı, Hüseyin Utku; Keleş, Nazlı; Gökçen Akkurt, GüldenA geothermal energy-sourced drying system was tested for the thin-layer drying process of tomato slices at air temperatures of 40 degrees C, 50 degrees C and 60? and velocities of 0.5 m/s and 1.5 m/s to investigate system performance in terms of the first and second laws of thermodynamics. The energy and the exergy efficiency of the system were found to be 6.6% and 22.31%. The energy utilisation and energy utilisation ratio were calculated in the range of 1.271 kW-5.102 kW and 9.644%-39.56%, respectively. The exergy destruction, exergy efficiency and improvement potential of the drying chamber varied between 0.0198 kW-0.2621 kW, 59.74%-81.95% and 0.00486 kW-0.07396 kW, respectively.Article Citation - WoS: 1Citation - Scopus: 1Thermodynamic Re-Assessment of a Geothermal Binary Power Plant Operated in a Moderate-Temperature Geothermal Field(Inderscience, 2023) Özcan, Zeynep; Gökçen Akkurt, GüldenAn existing organic rankine cycle power plant which uses isobutane as working fluid is re-evaluated for different working fluids. The plant is first modelled by EES software; then the model is simulated for different working fluids obtaining heat transferred through the heat exchanger, net work output, energy and exergy efficiencies, and mass flowrate of the working fluid. Two parametric studies are conducted to evaluate the thermodynamic performance of the plant under a range of turbine inlet temperature (130°C–155°C) and geothermal resource temperature (152°C–161°C) for each working fluid. The study reveals that the highest cycle energy and exergy efficiencies are observed for R-152a at any geothermal resource temperature. R-152a resulted with 13.1% and 58.2% cycle energy and exergy efficiency, respectively at operation condition, whilst the lowest efficiency and net work output is calculated under n-butane presence.Article Citation - WoS: 4Citation - Scopus: 5Electrooxidation of Glycerol on Monometallic and Bimetallic Catalysts-Containing Porous Carbon Cloth Electrodes in an Alkaline Medium(Electrochemical Society, Inc., 2021) Çağlar, Başar; El Hassan, Youssef; Basak, Oğuzhan; Hepbaşlı, ArifThe electrooxidation of glycerol was studied on monometallic (Pt/C, Co/C, Ni/C, Cu/C) and bimetallic catalysts (PtCo/C, PtNi/C, PtCu/C) - containing porous carbon cloth electrodes in an alkaline medium to gain insight about the potentials of electrodes for simultaneous hydrogen and chemical production. Physical and chemical properties of catalysts were characterized by using X-ray diffraction, X-ray photoemission spectroscopy, and transmission electron microscopy while electrochemical characteristics of electrodes were investigated by cyclic voltammetry, choronoamperometry, and electrochemical impedance spectroscopy. Bimetallic catalysts-containing electrodes showed higher glycerol electrooxidation activities and stabilities compared to monometallic catalysts-containing electrodes. The highest activity was observed on the PtCu/C-containing electrode due to its higher electrochemical active surface area and low kinetic and mass transfer resistance. It was also found that the presence of porous carbon cloth had a considerable effect on the glycerol electrooxidation activity.Article Citation - WoS: 27Citation - Scopus: 29The Utilization of Plum Stones for Pellet Production and Investigation of Post-Combustion Flue Gas Emissions(MDPI, 2020) Dolzynska, Magdalena; Obidzinski, Slawomir; Piekut, Jolanta; Yıldız, GürayAgri-food waste is generated at various food cycle stages and is considered to be a valuable feedstock in energy systems and chemical syntheses. This research identifies the potential and suitability of a representative agri-food waste sample (i.e., plum stones) as a solid fuel. Ground plum stones containing 10, 15, and 20 wt.% of rye bran were subjected to pelletization. The pelletizer was operated at 170, 220, and 270 rpm, and its power demand for the mixture containing 20 wt.% of rye bran was 1.81, 1.89, and 2.21 kW, respectively. Such pellets had the highest quality in terms of their density (814.6 kg.m(-3)), kinetic durability (87.8%), lower heating value (20.04 MJ.kg(-1)), and elemental composition (C: 54.1 wt.%; H: 6.4 wt.%; N: 0.73 wt.%; S: 0.103 wt.%; Cl: 0.002 wt.%; O: 38.2 wt.%). Whole plum stones and pellets were subjected to combustion in a 25 kW retort grate boiler in order to determine the changes in the concentrations of NO, SO2, CO, CO2, HCl, and O-2 in the post-combustion flue gas. Collected results indicate that plum stone-rye bran pellets can serve as effective substitutes for wood pellets in prosumer installations, meeting the Ecodesign Directive requirements for CO and NO.Article Omega type solar charge station(Croation Union of Mech. Engineers and Naval Architects, 2002) Atagündüz, GürbüzAcid rains, greenhouse effect, smog and depletion of ozone layer arc some of the factors, which lead to the air pollution in big cities all over in the world. One of ways to reduce the air pollution in big cities is the introduction of electro or hybrid cars. The present work deals with a photovoltaic charge station, which could be installed on a garage roof with the dimensions about three meters by six meters in order to charge the battery of an electro car. The present work consists of two parts. First part deals with the theoretical design of the charge station, which has been started during a research stay of the author* in Germany. The second part is an experimental work, completed at Izmir Institute of Technology as a MS-Thesis. The present work bases on the original idea of the author, used in a previous work for the field of heliostats of the Solar Thermal Power Plant in the University Ege. The idea is to create a fix mirror area, which should acts as if it were a sun-tracking array. The theoretical design work and the results of the experiments have shown that the idea is applicable also to photovoltaic fields.