A Systematic Numerical Tool Accounting for Boiler Feed Water (BFW) in Total Site Heat Integration

Energy efficiency in industrial field gains very much attention around the world. Total Site Heat Integration (TSHI) is proposed as a solution to increase energy saving opportunities. Graphical method, numerical method and mathematical model are used to benchmark, design and optimise centralised utility system in multiple processes site. Several publications have studied multiple utility targeting with sensible heat in individual plant heat integration. However, most studies done in THSI do not account for the sensible heat for heating up the boiler feed water (BFW) to become steam. In this work, an organised methodology is developed for targeting the minimum utility requirement in a centralised steam system that involves the heating of BFW to saturated steam condition, as often encountered in the process plant with centralised condensate system. An extended Total Site Problem Table Algorithm (TS-PTA) is proposed as a systematic numerical tool for accounting the sensible heat while targeting the Total Site utility requirement. An illustrative example is used to verify the methodology developed, which shown 11 MW of heat has used for heating BFW. TS-PTA also shows that 7 MW and 81 MW of hot and cold utility are minimum required for the TS.