Heat exchanger network (HEN) retrofit has been widely studied to achieve energy savings. Different types of heat exchangers such as shell and tube, double-pipe, spiral plate, and spiral tube have their working temperature ranges and prices. However, considering the type of heat exchangers in the HEN retrofit process is rarely seen in previous publications. Selecting suitable types of heat exchangers according to their temperature ranges and prices is a crucial aspect in industrial implementation. The above-mentioned issue can be solved by the proposed Shifted Retrofit Thermodynamic Grid Diagram with the temperature range of heat exchangers (SRTGD-TR). The aim is to minimise the total cost, including utility cost and capital cost. The methodology is illustrated using a case study.
