Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
Browse
2 results
Search Results
Master Thesis Modelling and Controlling of Hybrid Energy Systems With Hydrogen Storage(01. Izmir Institute of Technology, 2023) Denizli, Osmancan; Çağlar, Başar; Altın, MüfitHybrid renewable energy systems are gaining more attention for the problems like Global Warming and high CO2 emissions. Another topic that increases its popularity is hydrogen. Because it is a very good alternative fuel. In this work, every component of a basic Hybrid Renewable Energy System (HRES) will be modeled and short-time simulations will be made for any transient response of individual components. MATLAB Simulink is used for every model and simulation. HRES includes a wind turbine, PV array, battery energy storage, and electrolyzer. The system is also grid-connected. Additionally, different control strategies are investigated, obtained, and created. Maximum Power Point Tracking (MPPT) algorithms for Wind Energy Conversion System (WECS) and PV array were conducted. A control algorithm that combines the battery and the PV array was made and necessary circuits were designed. An overall model for different sizes and operations is created. One-day-long simulations were made for 11 different cases. The user can alter the overall model for different turbines, PV modules, and battery sizes. The total amount of hydrogen produced, energy generation, and consumption were observed for every case.Master Thesis Optimum Design of Composite Hydrogen Pressure Vessels by Stochastic Search Methods(Izmir Institute of Technology, 2018) Sayı, Abdülmecit Harun; Artem, Hatice SeçilFiber-reinforced composite materials are extensively used in many engineering applications such as aircraft wings and frames, vehicle drive shafts, sport equipment, and pressure storage vessels. One of the reasons for the extensive use of laminated composite materials is their tailorable nature, which allows them to satisfy specific design objectives in an application. As an application, hydrogen-powered fuel cell vehicles require high amount of hydrogen to increase distance range. Hence, hydrogen is pressurized at elevated rates. Since, it is hard to satisfy safety and weight regulations for high pressure gas, composite storage vessels offering high strength with low weight are preferred. Optimization techniques are applied to the design of composite pressure vessels to maximize strength with comprising weight restrictions. In the thesis, first-ply failure optimizations of stacking sequence design of cylindrical composite pressure vessels with metal liner having 700-bar working pressure and safety factor of 2.0, have been performed using stochastic search algorithms which are Differential Evolution and Nelder Mead. Three separately categorized failure theories; Tsai-Wu, Maximum Stress and Hashin-Rotem criteria have been incorporated to failure analysis of the vessel designs. In addition, the effects of volume on the stacking sequence design have been investigated. Hence, four volumetrically separated pressure vessel designs have been considered. Change in volume has been provided by inner radius. Single objective optimization has been set to minimize failure criteria index which incorporates into classical lamination theory. Fiber orientation angles and number of plies are design variables. CPU time has been calculated to compare the workloads of algorithms. In conclusion, optimized pressure vessels have provided design targets and the difference in volume has caused variable fiber angle orientations, number of plies and CPU time.