An algorithmic approach to generate timesharing schemes for multi-period HEN designs

Without changing the conceptual configuration of a given multi-period HEN design, it has been shown in this work that the total capital cost can be significantly reduced by allowing a chosen set of exchangers to be shared by more than one match in different periods. Systematic synthesis strategies have been developed to generate the timesharing schemes needed for realizing this novel idea. The proposed strategies can be implemented either with generic area allocation algorithms or by solving a MINLP model. The former approach is not only easy to use but also effective for creating practical solutions which are near optimal. Somewhat better results may be obtained by using the latter method with considerably larger computation effort. Based on the extensive case studies performed so far, it was found that both approaches are applicable for generating the timesharing schemes that achieve significant saving in capital investment.