عنوان مقاله [English]
Identification of the location of energy loss is the most important step in energy optimization of industrial plants. Exergy analysis specifies the points of irreversibility and the amount of exergy loss. According to the equipment exergy loss, the energy bottlenecks of unit will be specified. Exergy Analysis of Abadan catalytic reforming unit shows heat exchangers, which preheating the feed streams of unifiner and platformer fire heaters (H-E-1 and P-E-1), have the maximum exergy loss of heat exchangers network. Adding two pairs of heat exchangers to these heat exchangers, the network is retrofitted. Therefore the exergy loss reduces 4.0769 (MMBtu/hr) in winter and 4.4563 (MMBtu/hr) in summer. This retrofit needs approximately $215000 investment and will also reduce heat duty of hot and cold utilities to 15 and 9 MMBtu/hr, respectively. This retrofit causes 7% energy saving. The payback period of this investment is 45 months and then will save $57000 annually.