EVHE – A new method for the synthesis of HEN

•A new method for the synthesis of heat exchanger networks is presented.•A new form of data depiction called sequence plot is introduced.•The new algorithm is a major advancement of the vertical heat exchange method.•Resulting networks are less complex and therefore more feasible.•Varying heat exchange coefficients of the streams are taken into account.

In this paper a new algorithm for the synthesis of cost optimal heat exchanger networks (HEN), called enhanced vertical heat exchange (EVHE), is introduced. It adopts aspects of the conventional vertical heat exchange but differs where, instead of using composite curves (CC), a new form of graphic depiction of the problem's data in a temperature–enthalpy diagram is implemented. Another deviation from the conventional heuristics is to allow parallel and crossed connections of streams in the same diagram. The resulting HENs have in common that they are the solutions with a minimum number of heat exchangers (HE) for a default amount of integrated heat. Furthermore, the new method allows the option to take into account varying heat transfer coefficients by means of a substitution of the streams’ data with virtual temperatures. The EVHE algorithm proved to produce better results on problems taken from the literature.