Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Conference Object Parameter Analysis of a Biomass Based SOFC-Engine Polygeneration System for Cooling, Heating and Power Production(Scanditale AB, 2020) Zhu, Pengfei; Guo, Leilei; Yao, Jing; Ren, Jianwei; Kapci, Mehmet Fazil; Bal, Burak; Zhang, Z. X.In order to meet the demand of clean and efficient energy conversion technology, a novel combined cooling, heating and power (CCHP) system fueled by biomass is proposed. This system is consists of biomass gasification unit, solid oxide fuel cell, IC engine unit and absorption refrigeration chiller. Thermodynamic model of the CCHP system are developed and then parameter analysis is adopted to optimize the performance of this system. The effect of air equivalent ratio (ER), steam biomass ratio (S/B) and the fuel utilization factor of SOFC (μ) on the performance of the entire system are studied. The results show that increase of S/B and μ will prompt the electrical efficiency, while the increase of ER has a negative effect on electrical efficiency. The exergy analysis shows that the exergy destruction of biomass gasification process and engine is larger, which is 454.5 kW and 207.2 kW respectively. On the contrary, exergy destruction of SOFC and absorption refrigeration chiller are 15.9 kW and 52.8 kW, respectively. © 2024 Elsevier B.V., All rights reserved.Conference Object Numerical Study of Magnesium-Based Metal Hydride Reactor Incorporating Multi-Phase Heat Exchanger for Thermal Energy Storage System(Scanditale AB, 2021-03-02) Yao, Jing; Zhu, Pengfei; Ren, Jianwei; Kapci, Mehmet Fazil; Bal, Burak; Kurko, Sandra V.; Zhang, Z. X.Metal hydride based thermal energy storage system is regarded as a promising method due to its good reversibility, low cost, and no by-product. Multi-phase heat exchange has much higher heat transfer coefficient than single-phase fluid heat exchange, thus facilitating the steam generation. In this study, a two-dimensional model of the metal hydride reactor using multi-phase heat exchange is proposed to estimate the performance and its feasibility of application in the concentrated solar power system. The results show that the velocity of the heat transfer fluid should match well with the thermal conductivity of the metal hydride bed to maintain the heat flux at a relatively constant value. The match of thermal conductivity of 3 or 5 W/(m·K) and fluid velocity of 0.0050 m/s results in the heat flux up to about 19 kW/m2, which is increased by 3 orders of magnitude than single-phase heat exchange. This study helps to facilitate the widespread application of metal hydride based thermal energy storage system in the concentrated solar power system. © 2024 Elsevier B.V., All rights reserved.Conference Object Investigation of Temperature and Pressure Effect on the Hydrogen Sorption Kinetics in the Interface of Mg/MgH2 by Molecular Dynamics(International Association for Hydrogen Energy, IAHE, 2022) Kapci, Mehmet Fazil; Wu, Zhen; Bal, BurakMolecular dynamics simulations were performed in order to analyze the hydrogen sorption kinetics between αMgH<inf>2</inf> and hcp Mg structures under different temperatures and pressures. Results showed that hydrogen desorption from magnesium hydride and absorption by hcp magnesium increase at the higher temperatures. During the hydrogen desorption from magnesium hydride and absorption into hcp magnesium, crystallographic orientation change in the magnesium atoms was observed. At 400 °C, the pressure was found to have a negative impact during the hydrogen desorption from magnesium hydride due to the prevention of recrystallization. © 2023 Elsevier B.V., All rights reserved.Book Part Citation - Scopus: 2Design of Bio-Joint Shaped Knee Exoskeleton Assisting for Walking and Sit-to(Springer International Publishing, 2018-10-14) Kapci, Mehmet Fazil; Unal, RamazanIn this study, a bio-joint shaped knee joint exoskeleton is presented. This design is meant for avoiding misalignment of the exoskeleton joint with the biological knee joint. For this purpose a cam mechanism has been designed to prevent the misalignment from translation of the femur on tibia. Additionally, walking and sit-to-stance is passively assisted with a spring element that is activated with the heel contact. A single spring is used for both walking and sit-to-stance, due to the similar characteristics of the gait cycle and initial phases of the sit-to-stance in joint stiffness. © 2018 Elsevier B.V., All rights reserved.