A POD Approach for the Analysis of a Multi-Stream Heat Exchanger of a Cold Box: Comparison of two different Coefficient Approximations

Two different coefficient approximation methods are implemented during a Proper Orthogonal Decomposition (POD) approach to analyze a Multi-Stream Heat Exchanger used in cold boxes. Variable-property three-dimensional modeling is used to collect snapshots. Fluid-solid domains are modeled conjugately, and a dimensionless vector-valued approach is suggested for the bases. The Kriging (KRG) and Inverse-Distance Weighted (IDW) methods are employed to approximate the base coefficients according to the Reynolds numbers of streams, and the results are compared. The field is reconstructed for a full interpolation of the POD weighting coefficients and also for a partial extrapolation of them. CFD solution is the criterion for the calculation of deviations. Based on the total heat exchange and exit temperature prediction , the KRG method outperforms the IDW method in ۸۳% of the cases. IDW has better results in some extrapolated cases, although the deviation is substantial for both approaches in these cases. The necessary number of bases depends on the required post-processing for the intended parameter.

Keywords:

Multi-Stream Heat Exchanger , Proper Orthogonal Decomposition (POD) , Deviation accumulation , Kriging , Inverse-Distance Weighted