SynFlex: A Computational Framework for Synthesis of Flexible Heat Exchanger Networks

Abstract

Abstract This work presents a computational framework for automatically generating flexible Heat Exchanger Networks (HEN) over a specified range of expected variations in the inlet temperatures and flowrates of the process streams, such that the Total Annual Cost (TAC) involving the utility consumption, heat exchanger areas and selection of matches are optimized simultaneously. The synthesis of the network was performed using as a basis the superstructure proposed by Yee and Grossmann (1990) . The framework SynFlex, which has been implemented in GAMS and Matlab, is based on a two-stage strategy. The first stage (design phase) is performed prior to the flexibility analysis where the design variables are chosen, i.e. the existence and dimension of the equipments. In the second stage the feasibility of the proposed design is tested so that the control variables are adjusted during operation on the realizations of the uncertain parameters. The proposed computational framework SynFlex yields a HEN design which is guaranteed to operate under varying conditions ensuring stream temperature targets and optimal energy integration. The application of the proposed HEN synthesis strategy and its computational efficiency are illustrated with some numerical examples.