Title: Thermodynamic comparison of a steam, hot water and hot air production system consuming Soma and Afsin lignites under stoichiometric conditions

Authors: Sefa Yalcin; Adnan Midilli; Alp Er S. Konukman

Addresses: Energy Institute, TUBITAK Marmara Research Center, Gebze 41470, Kocaeli, Turkey ' Department of Mechanical Engineering, Energy Division, Recep Tayyip Erdogan University (RTEU), 53900 Rize, Turkey ' Department of Mechanical Engineering, Energy Systems Division, Gebze Technical University, Gebze 41400, Kocaeli, Turkey

Abstract: This study presents thermodynamic comparison of a steam, hot water and hot air production system consuming Soma and Afsin lignites under stoichiometric combustion conditions. For this purpose, using the results from stoichiometric combustion reaction and proximate-ultimate analyses of the lignite samples, energy and exergy analyses are performed. Moreover, the concept and capacity of steam (424 K, 5 bar), hot water (363 K) and hot air (573 K) production system are chosen in accordance with a tea factory. Consequently, in case of stoichiometric combustion of the same amount of Afsin and Soma lignites, it is observed that the amount of steam from Soma lignite combustion is approximately three times more than that of Afsin lignite combustion. Additionally, energy and exergy efficiencies of the system using Afsin lignite are calculated to be 66% and 19%, respectively while those of system using Soma lignite are estimated to be 73% and 24%, respectively.

Keywords: Afsin lignite; Soma lignite; energy; exergy; efficiency; stoichiometric combustion; heat-recovery.

DOI: 10.1504/IJEX.2017.085158

International Journal of Exergy, 2017 Vol.23 No.2, pp.101 - 128

Received: 24 Nov 2016
Accepted: 18 Dec 2016
Published online: 13 Jul 2017 *

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