OPTIMIZATION OF A LOUVERED FIN HEAT EXCHANGER WITH INDIVIDUALLY VARIABLE LOUVER ANGLES

In this study, a round tube and fin geometry with individually varying louver angles is analyzed. The thickness of the fin was neglected. Any interactions between the optimal louver angles and the fin thickness are hence not c aptured. A laminar and steady calculation was performed, with symmetric boundary conditions. For the Reynolds number on the hydraulic diameter (Re Dh ) of 535 that was studied, a Von Karman vortex street is present behind the last tube row of heat exchanger. The steady calculation is hence only an approximation o f the reality, but is shown to give reasonable results. An ordinar y kriging response surface model was used to explore the enti re parameter space. Updates to the model were made on the basis of improving the Pareto front, visualizing the trad eoff between heat transfer and pressure drop. It is shown that t he use of individually varying louver angles allows increasin g the Colburn j factor by 1.3% for the same friction fact or, with respect to the optimal uniform louvered fin configu ration.

[1]  P. Roache.  Perspective: A Method for Uniform Reporting of Grid Refinement Studies , 1994 .

[2]  Jiin-Yuh Jang,et al.  3-D thermal-hydraulic analysis for louver fin heat exchangers with variable louver angle , 2006 .

[3]  Junqi Dong,et al.  Heat transfer and pressure drop correlations for the multi-louvered fin compact heat exchangers , 2007 .

[4]  Chi-Chuan Wang,et al.  Heat transfer and friction correlation for compact louvered fin-and-tube heat exchangers , 1999 .

[5]  Cristian Cuevas,et al.  Thermo-hydraulic characterization of a louvered fin and flat tube heat exchanger , 2011 .

[6]  Chi-Chuan Wang,et al.  A numerical investigation of louvered fin-and-tube heat exchangers having circular and oval tube configurations , 2001 .

[7]  Henk Huisseune,et al.  Study of junction flows in louvered fin round tube heat exchangers using the dye injection technique , 2010 .

[8]  Andy J. Keane,et al.  Recent advances in surrogate-based optimization , 2009 .

[9]  Danesh K. Tafti,et al.  Fin–tube junction effects on flow and heat transfer in flat tube multilouvered heat exchangers , 2003 .

[10]  Jiin-Yuh Jang,et al.  Optimum louver angle design for a louvered fin heat exchanger , 2011 .

[11]  Sushanta K. Mitra,et al.  Numerical investigation of fluid flow and heat transfer over louvered fins in compact heat exchanger , 2007 .

[12]  Ralph L. Webb,et al.  Performance evaluation criteria for use of enhanced heat transfer surfaces in heat exchanger design , 1981 .