A NEW METHOD FOR HEAT-EXCHANGER NETWORK SYNTHESIS USING AREA TARGETING PROCEDURES

Many methods have been proposed for heat exchanger network (HEN) synth esis. The algorithmic methods rely heavily on sophisticated mathematic al programming techniques, whilst heuristic methods do not always prod uce the best designs, although, current versions of the pinch design m ethod yield improved solutions by utilising the ''driving force plot'' and the ''remaining problem analysis''. Such designs are evolved by s equential choice of matches, however, with sequential matching, it is not always clear which of a number of available candidate matches shou ld be chosen, although some will determine the eventual network cost. An alternative new heuristic method is proposed which does not rely on pinch decomposition. The composite curves are decomposed into a numbe r of ''blocks'' (which may exceed the two blocks formed by pinch decom position). Within each block, straight line segments approximate the c omposite curves giving ''quasi-composites''. Area calculations based o n maximum heat exchange are performed between all hot and cold feasibl e matches in each block and these areas are compared with the ideal ar eas from the quasi-composites. A good set of design matches can then b e simultaneously selected with any matching constraints taken into acc ount by parallel examination of the whole set of possible matches in a block. Designs using this approach will be compared to those from oth er methods.