Energy Systems Engineering / Enerji Sistemleri Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4752
Browse
4 results
Search Results
Article Citation - WoS: 29Citation - Scopus: 33The Effect of Heat Transfer Characteristics of Macromolecule Fouling on Heat Exchanger Surface: a Dynamic Simulation Study(Wiley, 2023) Karimi Shoar, Zahra; Pourpasha, Hadi; Zeinali Heris, Saeed; Mousavi, Seyed Borhan; Mohammadpourfard, MousaAt the city gate gas pressure reduction stations (CGSs), to prevent natural gas from forming a hydrate in the throttle valve, the natural gas is heated by the heater before reaching the pressure relief valve. Heat exchangers are an essential component of industrial processes that contribute significantly to total system energy. Since the element impacting heat exchanger performance is the fouling process, all fouling processes and models were dynamically simulated in this study. Through coding in the C++ language and simultaneous use of fluent functions, or, in other words, user-defined function (UDF), fouling-related models were defined for this software. The dynamic simulation was performed, and parameters such as fouling strength and layer thickness were calculated. The effects of changing operating conditions, such as gas inlet velocity, surface temperature, and fouling species concentration on fouling growth, were also evaluated. As the concentration of fouling species increased, the fouling rate also increased. The amount of supersaturation and fouling rate increased as the surface temperature increased. Due to the operational limitations of the system, to reduce the fouling rate, the gas inlet velocity should be as high as possible, and the fluid inlet temperature, surface temperature, and concentration of fouling species should be as low as possible. In this study, the required time to reach the efficiency of 70% of the heat exchanger was calculated using the modelling of this chamber, which was equivalent to 190 days. Additionally, the critical thickness of the fouling layer at this time was 3.5 cm.Article Citation - WoS: 6Citation - Scopus: 9Impact of Climate Change on Indoor Environment of Historic Libraries in Mediterranean Climate Zone(Inderscience Enterprises, 2019) Turhan, Cihan; Durmuş Arsan, Zeynep; Gökçen Akkurt, GüldenMost historic library buildings house valuable paper-based collections that are kept in unconditioned environments. This vulnerable cultural heritage is expected to be highly affected by climate change in the future. In this study, indoor microclimate of an unconditioned historic library, Necip Pasa Library (Izmir, Turkey) is analysed for existing conditions and future climate data. The measured and predicted indoor microclimate data from 'present' till 2080s are used to determine possible chemical degredation risk on library collection and human comfort. Comparison of periodic results of future climate data indicates an increase in temperature that could cause both an increase in chemical degredation risk on the library collection and a decline in thermal comfort conditions. Mitigation of climate change effects on library collection and human comfort requires taking some actions such as adding light and adaptive mechanical solutions.Book Part Citation - Scopus: 2Ventilation Strategies for the Preventive Conservation of Manuscripts in the Necip Paşa Library, Izmir, Turkey(Elsevier, 2018) Coşkun, Turgay; Şahin, Cem Doğan; Gülhan, Özcan; Durmuş Arsan, Zeynep; Gökçen Akkurt, GüldenLibraries are specific spaces in which the indoor microclimate should meet rigorous requirements such as the thermal comfort of humans and the conservation of books, manuscripts, and cultural property. An inadequate indoor microclimate (mainly temperature, relative humidity, and their fluctuations) in libraries may cause chemical, biological, and mechanical degradations in paper-based collections. In this chapter, the indoor microclimate of the Necip Paşa Library, the historic library located in Tire-Izmir, Turkey, is discussed from the perspective of the preventive conservation of manuscripts. The library, which has no active heating, cooling, and ventilation system, was modeled with the help of a building energy simulation tool, DesignBuilder. The indoor temperature and relative humidity were monitored throughout 1 year and the model was calibrated with respect to these measurements. To reduce the risks of the manuscripts degrading, ventilation strategies were proposed including natural and mechanical control. The results showed that risks of chemical degradation can be diminished to some extent. © 2018 Elsevier Inc. All rights reserved.Article Citation - WoS: 7Citation - Scopus: 7The Importance of Internal Heat Gains for Building Cooling Design(Yıldız Teknik Üniversitesi, 2017) Coşkun, Turgay; Turhan, Cihan; Durmuş Arsan, Zeynep; Gökçen Akkurt, GüldenThis paper aims to investigate the effect of internal heat gains on the cooling load of a building. The house occupied by three adult men is selected as the case study for paper. The house is in the third floor of the apartment. The apartment has four flats and it has no insulation around the external walls. The heat dissipation from lighting devices, electrical equipment and the occupants are calculated by using the DesignBuilder v4 Beta release simulation program. The temperature of the house is observed during three weeks by using hobo data loggers and calibration of the measurements is made with respect to weather data file of the flat. Detailed schedule based on time of operation and occupancy is prepared to get more accurate results. Annual energy consumption and cooling load of the house is determined by using the dynamic simulation program.