Numerical simulation and parametric analysis of defrost water evaporation in no-frost refrigerators

This study investigates defrost water evaporation in domestic no-frost refrigerators, a process governed by complex multiphase physics and coupled thermodynamic parameters. An experimental setup was designed and validated through three repeatability tests, demonstrating high reliability with a maximum deviation of 3% in water evaporation measurements. Concurrently, a three-dimensional computational fluid dynamics (CFD) model utilizing the realizable k-ε turbulence model was developed and validated against experimental data, yielding a mean deviation of 4.0%. A full factorial design of experiments (DOE) was conducted to systematically evaluate the influence of hot-gas tube heat source, condenser surface temperature, and fan speed. Pareto analysis revealed that while the effect of hot-gas tube heat source is the primary driver of evaporation, fan-induced air movement at the water surface also plays a critical role. Finally, a highly accurate predictive empirical correlation was established (R²: 0.9963, RMSE: 5.88) to serve as a robust tool for optimizing domestic defrost systems. This research contributes to the literature by resolving the underlying evaporation physics and proposing a validated numerical framework for industrial design optimization.