Area Targeting of Heat Exchanger Network (HEN) Using a Modified Pinch Technique.

Abstract

Aspen Hysys version 8.6 which is a modified pinch tool was used to minimize the area of two heat exchanger networks problem and the results obtained were compared with those of other methods used by researchers that have solved the same problems. Stream data adopted from previous research work comprising the inlet and outlet temperatures, heat capacity flow rate, and specific heat capacity were imputed and solved for minimum area using the principle of modified pinch technology embedded in the Aspen Hysys software.The minimum approach temperature, composite curve, grand composite curve and the grid diagram representation are all series of steps employed in the methodology to achieve minimal area targeting using the Aspen Hysys. The problems solved in this research compared well with those of other researchers and even obtained a smaller exchanger area when compared with the non-linear programming technique (NLP). For instance, an area of 22.17m2was obtained in the first example as against 29.84m2 obtained by the non-linear programming techniques, resulting in a percentage difference of 25.7%. Also in the second example solved in this research, an area of 106.4m2 was obtained against 188.9m2obtained with the NLP technique which gives a percentage difference of 43.67%.The overall assessment of the results on area targeting on these problems using Aspen Hysys points to the fact that the traditional pinch technique can still obtain results that are as good as those obtained using mathematical programming techniques in heat exchanger networks (HENs).