Simultaneous Optimization Models for Heat Exchanger Network Synthesis with Multiple Utilities: A New Strategy by Using Utility Sub-stage

In simultaneous method area of heat exchanger network synthesis (HENS), a mixed integer nonlinear programming (MINLP) model with stagewise superstructure is developed to minimize the total annualized cost (TAC). However, most of the preceding researches do not allow to consider the multiple utilities. Unlike previous superstructure, the utility sub-stage is located between the stages and multiple utilities are arranged in series. The heuristic, the optimal utility position should not be located in splitting stream, increase the searching area by expanding the number of stage and reduce the model size which is related to convergence of model. To verify the model, two examples are proposed and they show the effectiveness by deducing a network superior to any reported methodology.