Heat Exchanger Network Retrofit with Fouling Effects

Heat exchanger networks (HENs) are important to petroleum and petrochemical processes because they help save hot and cold utilities, resulting in reduction of operating cost. The accumulation of fouling deposits on heat transfer surface area of exchanger cause more energy usage, especially in crude preheat train. In order to decrease extra utilities cost, regarding fouling in HEN is proposed to HEN retrofit. The model of HEN represented here is based on stage-wise superstructure by Yee and Grossmann (1990) with non-isothermal mixing assumption. In order to solve large-scale problem, the application of initialization and sequential techniques is required for solving complex mixed integer nonlinear programming (MINLP). There are three main initialization steps; MILP, NLP and MINLP steps. For our case study, The HEN retrofit with fouling effects will be applied to crude preheat train.