A conceptual programming approach for the design of flexible HENs

A conceptual tool is presented to address the flexibility and operability objectives for heal exchanger networks. The approach presents a screening model to accommodate the considerations ahead of design. The new development is essentially a targeting tool based on the Area Target Model that is a part of the Hypertarget methodology of(Chem, Engng. Sci., 54 (1999) 519; Chem. Engng. Sci., 54 (1999) 541; Chem. Engng. Sci., 54 (1999) 685). The targets accommodate for an early pre-processing of matches and assess implications due to parameter Variations. The feasibility targets provide ahead of design information on the costs incurred due to the variations. Flexibility targets assess the ability of the system Is handle variations for different driving forces. The potential of the matches to handle variations can be further exploited with superstructure schemes. The paper proposes a systematic algorithmic procedure that converges to flexible networks at the expense of only a minor set of additional constraints. Examples are presented to illustrate the approach, explain its ability to assess the impact of variations and prove the ease of its use in real-size problems. (C) 2001 Elsevier Science Ltd. All rights reserved.