Practicable total-site heat integration plan for retrofitting multiple heat exchanger networks

Abstract

Total-site heat integration (TSHI) is one of effective ways to improve energy efficiency for the process industry. Generally, the existing chemical plants in an industrial park were rarely constructed simultaneously and it is highly possible that each has already been equipped with an optimal heat exchanger network (HEN) at the time when its construction is completed. To further improve the overall performance of the entire site, a novel retrofit design strategy of these HENs is developed in this study using intermediate fluid(s). A two-stage procedure has been adopted to produce a practicable retrofitting plan. Three different revamp strategies are proposed in this work, while any of them can be applied to generate the cost-optimal designs first via indirect interplant heat exchanges. The benefit allocation schemes are then determined according to core and Shapley values in the second stage. The feasibility and effectiveness of proposed methodology are demonstrated in detail with a three-plant example. It is also plain to observe from the corresponding results that the applicability of the aforementioned design strategy is practicable in realistic environment.