The optimal design of heat exchanger networks considering heat exchanger types

A hybrid genetic algorithm for the optimization of heat exchanger networks (HEN) considering the heat exchanger types is developed. The algorithm is based on an analytical solution of the stream temperatures. The heat capacity flow rates of hot and cold streams and the heat transfer parameter (the product of the correction factor of logarithmic mean temperature difference F, the overall heat transfer coefficient k and the heat transfer area A) of each heat exchanger in the HEN are taken as the decision variables to be optimized. With this method, the investment and utility costs can be calculated separately in a user subroutine where the specificities of heat exchangers can be easily taken into account. An example from literature is used to illustrate the procedure, and better optimization results are obtained.