A Heat Exchanger Network Optimization Strategy for Dynamically Adjusting the Number of Split Flow

Abstract

The existing node-wise non-structural superstructure (NW-NSS) needs to set fixed number of split flow for all nodes in advance when optimizing heat exchanger networks, which is difficult to meet the needs of solving space and computational efficiency in the process of structural evolution, tending to limit the generation space of heat exchanger unit and reduce the global optimization quality of algorithm. Therefore, this paper proposes an optimal strategy to dynamically adjust the number of split flow for each node. Based on the distribution information of integral variables of real-time structure, this strategy dynamically increases the necessary split flow required by structural evolution and reduces the obstacle of ineffective structural evolution to optimization, improves the efficiency of the algorithm to jump out of the local search scope, and enhances the quality of optimization results. The strategy is applied to 16SP and 20SP cases, and the optimal heat exchanger network structures with the overall annual costs of 6 653 940 $/a and 1 711 886 $/a are obtained respectively. Compared with the optimal results in the literature, the results of this paper are reduced by 3 140 $/a and 3 202 $/a.