Synthesis of performance-optimal heat exchanger networks using attainable regions

The attainable region (AR) is a region in a performance space in which all physically realizable reactor network designs must exist. ARs have been used since the 1960s for solving reactor network synthesis problems. The benefits of these methods are that the feasibility of a performance target can be assessed prior to running a synthesis routine, the solutions they give are guaranteed to be physically realizable, and they are amenable to convex optimization. In this article, the theory of attainable regions is extended to bring these benefits to the heat exchanger network (HEN) synthesis problem, with constant thermo-physical properties and no stream splits. The HENS problems of the optimal outlet stream temperature and the minimum utility usage problems are linear optimization problems, solvable by simplex search with n - 1 state variables for an n-stream problem. The quality of solutions regarding number and size of heat exchangers is discussed, with examples. (C) 2020 Elsevier Ltd. All rights reserved.