Key topological features for optimized evaporator circuitry with enhanced manufacturability

We propose a systematic framework for identifying key topological features of optimized evaporator circuits. Favorable patterning and branching features were identified through in-depth analyses of influencing factors in terms of the heat transfer–pressure drop trade-off. The analysis was conducted using a fin-and-tube evaporator across two-dimensional cases involving three refrigerants and four cooling capacities. Variations in branch configuration primarily influenced local mass flux distribution, which in turn affected the pressure drop and local heat transfer coefficient. The ratio of the mean mass flux in the optimized circuit to that in the single-branch circuit decreased with increasing cooling capacity and decreasing latent refrigerant heat. Changes in return-bend patterns affected not only refrigerant-side temperature distributions but also the pressure drop ΔP and overall heat transfer coefficient UA by altering the distribution of local vapor quality. We demonstrated the topological features that effectively minimized ΔP for Zeotropic mixtures and enhanced UA with limited pressure drop for pure or pseudo-azeotropic refrigerants. Reduction in ΔP for R454C and increase in UA for R32 and R410A were accompanied by higher effective mean air temperatures T a,m as the corresponding topological features maintained an air temperature distribution similar to that of the refrigerant. The best-performing circuits outperformed those obtained through genetic programming in terms of coefficients of performance, manufacturability, and search efficiency. We show that identifying key topological features enables efficient and systematic procedures for optimizing refrigerant circuits with enhanced manufacturability for practical implementation in system designs.