A novel optimization approach of improving energy recovery in retrofitting heat exchanger network with exchanger details

Improving energy recovery with retrofitting heat exchanger network has been widely studied in academic and industrial communities. Distinct from most of existing works on HEN retrofit neglecting exchanger geometry, this paper presents a novel optimization method for dealing with the main exchanger geometry details in HEN retrofit problems. The addressed details of shell and tube exchangers include tube passes, shell passes, heat transfer intensification, logarithmic mean temperature difference (LMTD), and LMTD correction factor (FT), which are systematically identified under given objective function and topological constraints in the existing heat recovery systems. Based on the recent works proposed by Pan et al. [1] on HEN retrofit scenarios addressing network topology modification, an efficient optimization framework, consisting of two optimization stages with the implementation of MILP-based iterative method [2], has been developed to deal with the computational difficulties associated with the nonlinearity of LMTD and FT. Case study from literature examples are carried out to demonstrate the validity and soundness of the proposed approach, showing that the new proposed approach is able to provide realistic and practical solutions for debottlenecking of HEN with systematic consideration of exchanger details.

► Exchanger details are addressed for HEN retrofit.
► A new mathematical programming model considering FT is built up.
► An efficient optimization approach is developed for complex nonlinear model.
► The proposed method can perform much better than the existing methods.
► The proposed method is still efficient for practical application.