Browsing by Author "Erek, Aytunc"

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Citation - WoS: 5
Citation - Scopus: 4
Development of an integrated underfloor heating system model in TRNSYS and performance assessments
(Elsevier Ltd, 2024) Okan Gök; Nezir Yağız Çam; Ersin Alptekin; Mehmet Akif Ezan; Aytunç Erek; Gok, Okan; Alptekin, Ersin; Ezan, Mehmet Akif; Erek, Aytunc; Cam, Nezir Yagiz
In this study a transient model for a solar underfloor heating system with a sensible heat thermal energy storage (SHTES) system to meet the heating demand of a residential building is developed in TRNSYS software. As a novelty in the current model rather than using the built-in modules in the software an in-house MATLAB routine is implemented in TRNSYS to simulate the spatial and temporal variations inside a 2D slab-type SHTES tank. Long-term dynamic simulations are conducted to discuss the influences of the design and working parameters on the (i) energetic and exergetic performances (ii) solar fraction and (iii) CO2 emissions associated with the alternative underfloor heating systems. Parametric analyses are performed for climatically different locations such as Izmir (Csa: Hot-summer Mediterranean climate) and Erzurum (Dfb: Warm-summer humid continental climate). Variations in charging loop mass flow rates have minimal impact on the overall system performance in Izmir and Erzurum compared to other design and working parameters. The highest energy efficiencies of the solar-aided underfloor heating system for Izmir and Erzurum are achieved for a comfort temperature of 20 °C with 32.9 % and 24.6 % respectively. Regarding exergy efficiency the highest was determined as 4.04 % with a 23.5 °C comfort temperature in Izmir and 3.89 % with a comfort temperature of 20 °C in Erzurum. As a final result of the environmental assessments integrating solar SHTES especially with a natural gas-based auxiliary heater significantly reduces CO2 emissions by 99.6 % and 50.0 % in Izmir and Erzurum respectively. © 2024 Elsevier B.V. All rights reserved.
Citation - WoS: 31
Citation - Scopus: 32
Experimental exergetic performance evaluation of a novel solar assisted LiCl-H2O absorption cooling system
(ELSEVIER SCIENCE SA, 2014) Tuncay Gunhan; Orhan Ekren; Vedat Demir; Arif Hepbasli; Aytunc Erek; Arzu Sencan Sahin; Sahin, Arzu Sencan; Demir, Vedat; Ekren, Orhan; Gunhan, Tuncay; Hepbasli, Arif; Erek, Aytunc
This study proposes a novel solar assisted absorption cooling (SAAC) system and performs its exergetic analysis and assessment. The system was designed constructed and tested in Izmir Turkey. Water was used as refrigerant in the system. The performance of the whole system along with its main components was assessed through exergy analysis method. The results obtained gave the exergy destruction rate the exergy efficiency in various forms the relative irreversibility and sustainability index in both charging and discharging processes. A parametric study was also undertaken to investigate the effect of the various dead (reference) state temperatures ranging from 30 degrees C to 42 degrees C with an interval of 4 degrees C on the entire system efficiency. In this context the exergy efficiency of the whole system varied between 13.1 and 43.2% as the dead state temperatures increase from 30 degrees C to 42 degrees C. The highest relative irreversibility values of 66.1% and 34.6% belonged to the solar collectors and the absorption chiller in charging and discharging processes at a dead state temperature of 34 degrees C respectively. (C) 2013 Elsevier B.V. All rights reserved.