Heat exchanger network synthesis without decomposition

Abstract

Most of the grassroot heat exchanger network (HEN) synthesis approaches decompose the synthesis problem into a series of three major tasks: (a) minimum utility cost calculation; (b) selection of the fewest number of matches; and (c) determination of a minimum investment cost HEN. This paper departs fro these approaches by posing the HEN synthesis problem as a single optimization problem, whose solution provides simultaneously the optimal utility consumption level, matches and network configuration. This approach alleviates the need for either estimating the optimal utility levels via targetting schemes, or for performing several optimization loops to determine the optimal utility consumption level and process stream matches. The approach can be applied to both pseudo-pinch and strict-pinch design problems. The proposed approach compares favorably with: (a) decomposition techniques; (b) with the simulated annealing approach; and (c) with other simultaneous approaches. The method is illustrated with three example problem