Exergy analysis of oxygen bottom blown furnace in SKS lead smelting system

In order to reveal the mechanisms of the losses as the result of internal and external irreversibility in a bottom blown furnace in SKS lead smelting process,an exergy analysis model of the furnace was developed by adopting exergy balance approach. Energy and exergy loss distribution and exergy efficiency in the procedure of the furnace were computed and analyzed,and comparison between energy conservation analysis and exergy analysis was made. The results show that the exergy efficiency of the SKS bottom blown furnace is only 25.28% if there is no flue gas recovery equipment and waste heat recovery device,whereas the total exergy loss,which includes exergy loss caused by exhaust smoke,physical exergy loss of the output production and internal exergy loss due to irreversibility factors such as chemical reaction,etc.,accounts for 74.72%. Hence the furnace has great energy saving potential. The total exergy flow of 1.527 275 2×1011 J/h is much greater than the total heat flow of 6.399 425 0×1010 J/h,which shows that the essence indwelled in material and energy flow of the SKS bottom-blowing furnace is better manifested through exergy analysis than through energy conversation analysis. Therefore,the exergy efficiency approach should be widely used to assess the performance of metallurgical furnaces similar to bottom blown furnace.