Enhanced optimization of single and multi-component mass exchanger networks using parallelization and adaptive relaxation

This paper proposes an innovative simultaneous optimization approach for single and multi-component mass exchanger network synthesis (MENS). A retrofitted stage-wise superstructure and a parallelized random walk algorithm with compulsive evolution (RWCE) are adopted. An iterative calculation method is designed to satisfy the requirements of multi-component mass transfer, with a relaxation for the outlet composition of the lean streams. The parametric analysis shows that the relaxation coefficient plays a major role in driving the convergence of the method. To improve the robustness of the established model, an adaptive relaxation coefficient strategy is implemented for multi-component MENS problems. In a divergence situation, the outlet concentration of the lean stream can be adjusted automatically by a random relaxation coefficient. Finally, three industrial MENS examples are considered in this work, whose total annual cost (TAC) are reduced by 7179, 2212, and 551 $<middle dot>year-1. The corresponding optimization times are obtained to be 336, 125, and 145 s. The results indicate improvements in the economy and time, demonstrating that the parallelized RWCE can yield an optimal TAC and optimization efficiency compared to previous results. Overall, the adaptive relaxation coefficient strategy enhances the convergence for multi-component MENS problems.