Controllability analysis on delta temperature minimum to obtain operable and flexible heat exchanger network

Abstract

The requirement to synthesis heat exchanger network (HEN) is to select design target, whichis temperature minimum difference (ΔTmin). The purpose of ΔTmin is to optimize betweencapital cost and energy recovery. Currently, research on 8Tmin effects on HEN is commonlyassociated with the design outcomes such as energy recovery and cost. There are severalresearch studies on the effect of 8Tmin towards HEN design. An optimal ΔTmin for heatexchanger network is set between 5oC to 50oC, (Kemp, 2011). Jensen and Skogestad (2008)explained about specified 8Tmin effect on the wrong decision in the design of HEN.Abdullahi (2012) has studied the effect on ΔTmin contribution for individual process streamin the heat exchanger system. Basically, HEN synthesis method using 8Tmin focus more ondesign prospective. Not so many studies on the 8Tmin effect to the controllability part.Based on a new trade-off plot proposed by Abu Bakar et al (2014), lower ΔTmin has betterdesign criteria (higher energy recovery), however, higher in total cost and lowercontrollability criteria (higher flexibility and lower sensitivity). On the other hand, higher8Tmin has lower design criteria, however, lower in total cost and higher in controllabilitycriteria.