Automated retrofit targeting of heat exchanger networks

the aim of this paper is to develop a novel heat exchanger network (hen) retrofit method based on a new automated retrofit targeting (art) algorithm. art uses the heat surplus-deficit table (hsdt) in combination with the bridge retrofit concepts to generate retrofit bridges option, from which a retrofit design may be formulated. the hsdt is a tabular tool that shows potential for improved re-integration of heat source and sink streams within a hen. using the hsdt, retrofit bridges—a set of modifications that links a cooler to a heater to save energy—may be identified, quantified, and compared. the novel retrofit method including the art algorithm has been successfully implemented in microsoft exceltm to enable analysis of large-scale hens. a refinery case study with 27 streams and 46 existing heat exchangers demonstrated the retrofit method’s potential. for the case study, the art algorithm found 68903 feasible unique retrofit opportunities with a minimum 400 kw·unit–1 threshold for heat recovery divided by the number of new units. the most promising retrofit project required 3 new heat exchanger units to achieve a heat savings of 4.24 mw with a favorable annualised profit and a reasonable payback period.