1988 Volume 74 Issue 12 Pages 2270-2277
Exergy analysis was conducted on three ironmaking systems which were conventional ironmaking, direct reduction-electric furnace and smelting reduction systems. The exergy analysis is better than an enthalpy balance or a heat balance because exergy can express the quality of energy and evaluate different forms of energy like chemical, thermal, pressure and mixing energy by a unified measure.
According to the calculated results for the specified conditions, the smelting reduction system was the lowest in net exergy loss, however, the highest in overall output exergy. The development of the efficient heat recovery process is therefore required for this system. The direct reduction-electric furnace system was the highest in net exergy loss. However, nonfired pellets were found to be effective to reduce net exergy loss. In the conventional ironmaking system, net exergy loss of its constituent processes significantly depended on the injection rate of pulverized coal and on the charging amount of nonfired pellets.