MINIMUM-COST HEAT-RECOVERY BETWEEN SEPARATE PLANT REGIONS

Process plants are often divided into logically identifiable regions, each having associated processing tasks. Heat recovery between these seperate regions of a plant or process is becoming more frequently addressed, both in the literature and in practice. Most procedures to date for such interregion heat integration focus on minimizing energy costs. However, the methods only tentatively consider capital cost by aiming for a few number of interconnections between the process regions and by the assumed minimum temperature difference for heat exchange. So far, the energy-capital optimization for such situations has not been considered. This paper deals with the overall cost tradeoff between energy, heat exchange area and the number of interconnections for heat recovery between seperate regions of a plant or process. The purpose is to gain some understanding of the optimization and develop a procedure to obtain near-minimum cost designs for such systems.