Heat Exchanger Network Design Considering Inherent Safety

Pinch Analysis (PA) has been one of the most established methods since the 1970's for the design of a maximum heat recovery network. It has been one of the vital tools for maximising heat recovery in a process plant and for minimising the impact of rising energy cost as well as the environmental emissions. By combining the thermodynamic insights into the process heat recovery bottleneck with the HEN capital and operating cost tradeoffs, the PA has become an energy-saving tool widely used in the industry. However, further studies are needed to incorporate the safety aspect into HEN design using PA. Not fully considering the potential process hazards when selecting matches of hot and cold streams in a HEN can introduce process operation risk and consequently necessitate high investment in materials of constructions for heat exchangers. This work presents a new method for HEN design that incorporates the inherent safety index during the selection of heat exchanger matches in order to reduce the potential hazards of the optimal HEN design. Application of the extended PA on a case study shows that inclusion of the inherent safety feature has managed to localise the area of hazards, reduce the requirement for special materials of construction, and ultimately reduce the HEN capital cost by 10%. (c) 2014 The Authors. Published by Elsevier Ltd.