A novel simultaneous optimization model with efficient stream arrangement for heat exchanger network synthesis

Highlights: • HENS problem solved using novel chessboard representation. • An efficient process stream arrangement strategy is given that optimizes the search region. • A stochastic algorithm based on stage-wise chessboard model directly optimizes heat transfer area. • Four benchmark cases show the method's effectiveness compared to previous methods. - Abstract: This study aims to explore a new simultaneous synthesis method for heat exchanger network synthesis (HENS) problems to achieve the minimum total annual cost (TAC). A proposed efficient process stream arrangement strategy is used to reduce the search region for the optimal stream match and a stage-wise chessboard model expands the new feasible search region as well as avoiding missing optimal matches of other stream arrangements. Thus, the proposed stage-wise chessboard model combined with the arranged streams is a good improvement for managing the feasible search region for the heat exchanger network (HEN). Moreover, a recent stochastic algorithm called random walking algorithm of compulsory evolution (RWCE) is considered and used to optimize the heat transfer area directly. Finally, an ideal combination of the stage-wise model and the stochastic algorithm is applied to four different benchmark cases to show its effectiveness and the results show that simpler and more economic networks are found while using less computational time, which are all encouraging.