Browsing by Author "Reis, Alper"

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Exergetic Performance Analysis of a Solar Power System (Sps) in a High Plateau
(inderscience Enterprises Ltd, 2017) Genc, Naci; Mert, Suha Orcum; Reis, Alper
In this study, a comprehensive exergy analysis was applied to a solar power system (SPS) located in the city of Van, Turkey. Van was always known as a sun city throughout history with the name of TUSBA. It has an average of 300 sunny days a year, an altitude of 1727 m, and an average daily temperature of 9.85 degrees C. Considering how the need for sustainable and renewable energy sources -and knowledge over them - constantly increases, this SPS was built to reveal the true solar potential of the campus area of Yuzuncu Yil University of the city of Van, hopefully as a precursor for further large-scale SPS constructions in the region. A daily analysis considering energy production and global radiation was applied to the system in 2013 for 365 days. It was found that the yearly exergy efficiency of the system was 10% and total electrical energy production was 31,038.95 kWh, averaging 1763.5 kWh/kWp yearly.
Exergoeconomic Analysis of a Direct Formic Acid, Fuel Cell System
(Pergamon-elsevier Science Ltd, 2016) Mert, Suha Orcun; Reis, Alper
In this study, the exergoeconomic analysis of a direct formic acid fuel cell (DFAFC) power system for transportation applications is applied. This analysis covers system components such as compressor, humidifiers, heat exchangers and the cooling system besides the fuel cell stack. The effect of the operating temperature, pressure, current density, anode cathode stoichiometry and reference properties on system are evaluated, to predict the performance as close to real-cases as possible. The exergetic cost of power production is utilized and parametrically investigated regarding the exergy destructions and efficiency of the system. It is found that the optimum conditions for fuel cell operation is 323 K temperature, 3 atm pressure, 303 K reference temperature and 3 anode stoichiometry, respectively. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Experimental Performance Investigation of a Shell and Tube Heat Exchanger by Exergy Based Sensitivity Analysis
(Springer, 2016) Mert, Suha Orcun; Reis, Alper
Heat exchangers are used extensively in many industrial branches, primarily so in chemical and energy sectors. They also have important household usage as they are used in central and local heating systems. Any betterment on heat exchangers will serve greatly in preserving our already dwindling and costly energy resources. Strong approach of exergy analysis -which helps find out where the first steps should be taken in determining sources of inefficiencies and how to remedy them- will be used as a means to this end. The maximum useful work that can be harnessed from systems relationships with its environment is defined as exergy. In this study, the inlet and outlet flow rate values of fluids and temperature of hot stream both on shell and tube parts of a shell-tube heat exchange system have been inspected and their effects on the exergy efficiency of this thermal system have been analyzed. It is seen that the combination of high tube side inlet temperature, low shell side flow rate and high tube side flow rate are found to be the optimum for this experimental system with reaching 75, 65, and 32 % efficiencies respectively. Selecting operating conditions suitable to this behavior will help to increase the overall efficiency of shell-tube heat exchange systems and cause an increment in energy conservation.
Parametric Exergetic Investigation of a Direct Formic Acid Fuel Cell System
(Springer international Publishing Ag, 2018) Mert, Suha Orcun; Reis, Alper
Performance Assessment of a Direct Formic Acid Fuel Cell System Through Exergy Analysis
(Pergamon-elsevier Science Ltd, 2015) Reis, Alper; Mert, Suha Orcun
In this study, performance assessment of a direct formic acid fuel cell system is conducted, including evaluation of a broad set of operating parameters. The fuel cell system is modeled and simulated by using sub-routine developed by Matlab. The system components, such as compressor, humidifier and heat exchangers, are also taken into consideration. Effects of varying operating temperature, pressure, membrane thickness, current density, anode cathode stoichiometry and reference properties on the system are evaluated to predict the performance as close to real-cases as possible. It is found that increasing the temperature greatly favors the performance of the direct formic acid fuel cell system, low pressure and high reference environment temperature values have the same effect on the cell performance. The maximum exergetic efficiency by broad parametric investigation is estimated as 24%, where the power production is 10 kW. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.