Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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Author: search.filters.author.Gökçen Akkurt, GüldenCOAR Access Rights: search.filters.coarAccessRights.embargoed access

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  • Master Thesis
    Optimization of Energy Consumption and Thermal Comfort in Historic Buildings: Case Study of İzmir National Library Building, Türkiye
    (01. Izmir Institute of Technology, 2023) Özsavaşcı, Umut; Durmuş Arsan, Zeynep; Gökçen Akkurt, Gülden
    The 'library,' as a building type, is the visiting space of researchers and storage space of wisdom of past and present thinkers. Historic libraries host unique pieces of cultural heritage such as books, manuscripts, documents, maps, artifacts, paintings, sculptures, and frescos from the previous generations. The thesis aims to reduce energy consumption and improve occupants' comfort while paying attention to degradation risks of paper-based collections in the historic İzmir National Library Building, Türkiye. Thus, it examines building retrofit actions with different impact criteria and conducts the optimization tool to define the most optimal ones. First, three degradation risk assessment procedures were determined for the paper-based collections of the İzmir National Library Building. Within the scope of the thesis, the library building was monitored between 01.10.2016 - 01.10.2017. According to the results of the monitoring process, mechanical, chemical and biological degradation risk analyzes were carried out. The digital simulation model of İzmir National Library was prepared in DesignBuilder v. 7.0.0.102 software and calibrated monthly for a year via hourly air temperature data. Three retrofit optimization scenarios, i.e. neutral, low and high risk impact criteria, were defined by grouping different design variables such as glazing type, exterior door material, pitched roof floor construction, exterior wall construction, heating set point and cooling set point of HVAC system. The objective of optimization was reducing energy consumption and discomfort hours at the same time. The simulation results showed that all three retrofit actions reduced energy consumption and discomfort hours. Scenario 3 was the most successful among other scenarios, providing energy savings by 26.6% and reducing discomfort hours by 80.3%, according to the base case. Besides, there was no significant change in the degradation risk analyzes according to the base case.
  • Master Thesis
    Experimental Investigation and Computational Fluid Dynamics (cfd) Analysis of Geothermal Sourced Hot Air Drying
    (Izmir Institute of Technology, 2022) Keleş, Nazlı; Gökçen Akkurt, Gülden; Helvacı, Hüseyin Utku
    Drying is one of the oldest methods used to increase the product's shelf life and reduce transportation costs, consisting of heat and mass transfer between the product and the surrounding environment. One of the most common drying methods is hot air drying. The most critical parameters in hot air drying processes are drying air temperature, air velocity and relative humidity. Renewable energy resources can be used as heat/electricity in drying processes. Geothermal energy resources are highly suitable for hot air drying with their temperature compatibility and reliability. The geothermal resources in Turkey have a high potential for hot air drying. This Thesis examines tomato slices' quality parameters at different drying air temperatures and velocities. A cabinet-type geothermal sourced hot air dryer is installed in the Yenikale Heat Center of the Balcova-Narlidere Geothermal District Heating System in Izmir-Turkiye. Drying experiments are carried out at 40-60-80°C air temperatures and 0.5-1.5 m/s air velocities to examine their effects on drying kinetics and quality of dried tomatoes, such as pH, color, and moisture. With the help of the data obtained, drying time, drying rate, moisture rate, and effective diffusion coefficients are determined, and dimensionless moisture rate is modeled using thin layer models. Also, energy and exergy analyses are made for each experiment. Finally, experimental and simulation results are compared by using CFD to perform experimental design. The simulations created by using CFD are obtained in a much shorter time and more accurately since all materials used for the experiment are idealized.
  • Master Thesis
    Statistical Analysis of the Effect of Meteorological Parameters on Pm10
    (Izmir Institute of Technology, 2022) Birim, Necmiye Gülin; Gökçen Akkurt, Gülden; Turhan, Cihan
    Air pollution is a serious threat where the pollutants in the air in solid, liquid and gaseous states reach levels that would harm the natural balance of the environment and the lives of vital organisms. Especially in industrialized cities, in addition to the effects of urbanization, physical environment characteristics may also play a role in the formation of environmental problems. Therefore, it is of high importance to understand the characteristics of the natural environment in the studies on air quality, in order for urban spaces to be livable areas. In this study, the correlations between PM10 pollutant data and certain meteorological parameters that were obtained from 3 stations in İzmir province were statistically evaluated. PM10 data was studied according to pre-pandemic, mid-pandemic and post-pandemic periods between 2017–2021. Meteorological data was gathered for a twelve-month period between February 2021 and January 2022 and its effect on PM10 data for the same period was analyzed. In the statistical analysis that was performed via Minitab software, hourly average data of PM10 was the dependent variable; temperature, relative humidity, and wind speed and direction were the independent variables. In the analysis that Pairwise Pearson Correlation Coefficient (r) was used, the most significant correlation was found to be between relative humidity and wind speed.
  • Master Thesis
    Energy Performance Analysis and Materials Characterization of Aerogel Insulation Blankets
    (Izmir Institute of Technology, 2022) Alan, Selena; Gökçen Akkurt, Gülden; Akkurt, Sedat
    İzmir Geothermal Energy Inc. is a geothermal district heating company in İzmirTurkey that circulates hot water throughout the district via a 450 km of piping system and with the help of valves, pipes, and heat exchangers. As the distance traveled by the hot water is excessively long, heat losses are common. Rock wool is used as thermal insulation material, but the performance degraded over time because of water leakage. Instead of rock wool, aerogel insulation blanket use is evaluated in this study. Rock wool and three different aerogel insulation blankets are comparatively studied to assess their structures and thermal performances in two ways: the first is the characterization of materials by various physical and chemical analysis methods in the IZTECH-Integrated Research Center. The second way is to assemble a test setup on-site and make thermal measurements on the test setup for each aerogel insulation material, rock wool, and bare pipe. Heat loss calculations were conducted by EES software. The results are compared based on each characterization and thermal performance calculation. The thermal conductivity values of the insulation materials were calculated. Nonwetting properties were also checked to understand their hygrothermal properties. Compared with bare pipe, with the 10 mm thickness, rock wool decreases heat loss by 48-52%, and with the 10 mm thickness, the aerogel insulation blankets reduce heat loss by 57-61%. Finally, while aerogel insulation blankets have a better performance, they are more expensive than rock wool.