Browsing by Author "Balta, M. Tolga"

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Citation - WoS: 73
Citation - Scopus: 80
Comparative assessment of various chlorine family thermochemical cycles for hydrogen production
(PERGAMON-ELSEVIER SCIENCE LTD, 2016) M. Tolga Balta; Ibrahim Dincer; Arif Hepbasli; Hepbasli, Arif; Balta, M. Tolga; Dincer, Ibrahim
This study deals with a comparative assessment of various chlorine family cycles namely copper chlorine (CuCl) magnesium-chlorine (MgCl) iron-chlorine (Fe-Cl) and vanadium-chlorine (V-Cl) cycles which are driven by heat and/or electricity. Hydrogen production through thermochemical and/or hybrid cycles can play a significant role in reducing greenhouse gas emissions and hence offering opportunities for better environment and sustainability. In this paper we conduct energy and exergy analyses of the VCl cycle and examine both energy and exergy efficiencies of the cycle. We also undertake a parametric study to investigate how the overall cycle performance is affected by changing the reference environment temperature and cycle operating conditions. The performance of VCl cycle are evaluated and compared with CuCl MgCl and FeCl cycles. Furthermore these cycles are discussed and compared with each other through their advantages and challenges. As a result VCl cycle offers a good potential due to its high efficiency over 40% based on a complete reaction. In this regard VCl cycle appears to be one of the most promising low temperature cycles. It may therefore compete with other low temperature cycles such as copper-chlorine. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Citation - Scopus: 5
Environmental impact assessment of building energy systems
(Springer New York, 2013) Mustafa Tolga Balta; I. Dincer; A. Hepbasli; Balta, M. Tolga; Dincer, Ibrahim; Hepbasli, Arif; Caliskan, Hakan
This chapter deals with energy/exergy and environmental analyses of a low exergy heating system. A building with a volume of about 392 m3and a floor area of 140 m2is presented as a case study. For this building four different heating options are investigated namely (1) electric boiler (2) ground heat pump system (3) standard boiler and (4) solar collector. In this regard an energy and exergy analysis is employed to assess their performances and compare them through energy and exergy efficiencies. Also CO2 NOx SO2emissions of the considered systems are determined and compared with each other. Overall exergy efficiencies of the heating systems are found to be 4.0 10.1 7.6 and 35.7 %. CO2 NOx SO2emissions rate per year (kg emission/year) calculated for considered cases as 10726.32 4224.17 3737.56 and 337.67 11.14 4.39 3.40 and 3.35 and 116.34 45.82 3.68 and 3.66 respectively. The lowest environmental impact is provided by case 4. © 2017 Elsevier B.V. All rights reserved.
Citation - WoS: 12
Citation - Scopus: 12
Experimental exergoeconomic assessment of a desiccant cooling system
(Pergamon-Elsevier Science Ltd, 2013) Ertaç Hürdoǧan; Orhan Büyükalaca; M. Tolga Balta; A. Hepbasli; Tuncay Yilmaz; Büyükalaca, Orhan; Hürdoǧan, Ertaç; Yilmaz, Tuncay; Balta, M. Tolga; Hepbasli, Arif; Tolga Balta, M.
Desiccant cooling has become a well established technology in most parts of the world especially recently in Turkey. The increased growth of the technology was caused by the contribution of refrigerants used in conventional cooling systems to the depletion of the ozone layer. This technology provides a tool to control humidity (moisture) levels in conditioned air spaces. In this study a desiccant cooling system was designed constructed and tested in Cukurova University Adana Turkey while it has been successfully operated since 2008. Exergy cost energy and mass (EXCEM) analysis was applied to this system for the first time to the best of the authors' knowledge. The relations between thermodynamic losses and capital costs were also parametrically investigated and illustrated in figures. Based on the overall system (OS) results some components of the whole system namely the electric heater unit the expansion valve the pump the fresh air fan and the condenser fan were obtained to be inefficient. Particularly the electric heater unit was important as its exergy loss rate (Ṙex) value was 29.36 times greater than that of the OS. © 2013 Elsevier Ltd. All rights reserved. © 2013 Elsevier B.V. All rights reserved.
Citation - WoS: 40
Citation - Scopus: 47
Performance assessment of solar-driven integrated Mg-Cl cycle for hydrogen production
(Elsevier Ltd, 2014) Mustafa Tolga Balta; I. Dincer; A. Hepbasli; Hepbasli, Arif; Balta, M. Tolga; Dincer, Ibrahim
The present study develops a new solar energy system integrated with a Mg-Cl thermochemical cycle for hydrogen production and analyzes it both energetically and exergetically for efficiency assessment. The solar based integrated Mg-Cl cycle system considered here consists of five subsystems such as: (i) heliostat field subsystem (ii) central receiver subsystem (iii) steam generation subsystem (iv) conventional power cycle subsystem and (v) Mg-Cl subsystem. Also the inlet and outlet energy and exergy rates of all of subsystems are calculated and illustrated accordingly. We also undertake a parametric study to investigate how the overall system performance is affected by the reference environment temperature and operating conditions. As a result the overall energy and exergy efficiencies of the considered system are found to be 18.18% and 19.15% respectively. The results show that the Mg-Cl cycle has good potential and attractive overall cycle efficiencies over 50%. © 2021 Elsevier B.V. All rights reserved.