IJE TRANSACTIONS C: Aspects Vol. 31, No. 9 (September 2018) 746-755    Article in Press

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A. Zare Ghadi, M. S. Valipour and M. Biglari
( Received: July 28, 2017 – Accepted: January 23, 2018 )

Abstract    The present study carefully examined entropy generation during wustite pellet reduction to sponge iron. The finite volume method was used to solve the governing equations. The grain model was used to simulate the reaction rate. The reactant gases including carbon monoxide and hydrogen are converted to water and carbon dioxide after wustite reduction. Entropy is generated by heat transfer, mass transfer and chemical reactions. The entropy generated by these processes was discussed in the relevant sections. Based on the governing equations, the share of each process in the generation of entropy was calculated. The effects of gas ratio, porosity, and tortuosity and grain diameter of wustite pellet on entropy generation were investigated. According to the results, porosity and gas ratio were inversely proportional to the rate of entropy generation while tortuosity and grain diameter were directly proportional to entropy generation rate.


Keywords    Wustite Pellet, Entropy Generation, Mathematical Model, Grain Model


چکیده    در کار حاضر تولید آنتروپی در طول فرایند احیای گندله وستیتی به آهن اسفنجی مورد مطالعه قرار گرفته است. روش حجم محدود برای حل معادلات حاکم استفاده شده است. مدل دانه‏ای برای شبیه‏سازی نرخ واکنش مورد استفاده قرار گرفته است. پس از اتمام فرایند احیای وستیت گازهای احیا شامل مونوکسیدکربن و هیدروژن به آب و دی کسیدکربن تبدیل می‏شوند. آنتروپی از طریق انتقال حرارت، انتقال جرم و واکنش‏های شیمیایی تولید می‏شود. بر اساس معادلات حاکم، سهم هر فرایند در تولید آنتروپی محاسبه شده است. تاثیرات نسبت گاز، تورچیاسیتی و قطر دانه وستیتی بر روی تولید آنتروپی بررسی شده است. بر طبق نتایج، تخلخل و نسبت گاز رابطه عکس با نرخ تولید آنتروپی دارد در حالیکه تورچیاسیتی قطر دانه با نرخ تولید آنتروپی رابطه مستقیم دارد.

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