Capital Cost Targeting of Total Site Heat Recovery

A single uniform Delta T-min specification had been mostly considered for the evaluation of the trade-off between the heat recovery and the capital cost for individual processes. However, exploiting heat recovery on Total Site level offers additional potential for energy saving (Klemes et al., 1997). The current work deals with the evaluation of the capital cost for the generation and use of site utilities (e.g. steam, hot water, cooling water), which enables the evaluation of the trade-off between heat recovery and capital cost targets for Total Sites. The procedure involves the construction of Total Site Profiles and Site Utility Composite Curves and the further identification of the various utility generation and use regions at the profile-utility interfaces. This is followed by the identification of the relevant Enthalpy Intervals. The lower bound of the required heat transfer area can be then estimated which enables its further use in optimisation procedures.