Optimal heat exchanger network synthesis: A case study comparison

Heat exchanger network synthesis (HENS) is one of the most extensively studied synthesis/design problem in chemical engineering. This is attributed to the importance of determining energy costs and improving the energy recovery in chemical processes. Several synthesis procedures for heat exchanger networks have been published in the literature. However, only a modest number can be implemented as computer tools for the full automatic generation of network configurations. In spite of the computational methods evolution, some difficulties still need to be overcome. For instance: computational time, and problem convergence. In this work, the main approaches to solve the problem of heat exchanger network synthesis, sequential and simultaneous, were presented and implemented using the General Algebraic Modeling System (GAMS). Initialization strategies for generating feasible starting points are proposed. Five case studies with different dimensions, from four to 39 streams, are used as background to compare, and analyze the different approaches. The results showed the efficiency of the initialization strategies. Furthermore, the suitable solvers are also analyzed through solving each subproblem. Simultaneous approaches presented better performance than the sequential one. Finally, the main challenges involved in using different approaches is discussed to synthesize heat exchangers networks.