Performance analysis of perforated dew-point evaporative coolers using a two-dimensional numerical model

Driven by continuous growth in cooling power demand, low-energy, environmentally benign alternative cooling technologies are urgently required. This work establishes a two-dimensional coupled momentum-mass-energy numerical model for perforated dew-point evaporative coolers to characterize its cooling performance. The correlations of cooling performance with perforation size, perforation position and supply air ratio, as well as the optimal operating criteria, are systematically investigated. The results found that perforation layout in dew-point evaporative coolers must avoid reverse airflow; the feasible supply air ratio range narrows as perforations shift downstream, and the optimal perforation position lies near the inlet at low supply ratios while close to the outlet at high ratios. Results explained that the reflux ratio at the dry channel outlet can be flexibly adjusted, and the range of 0.2-0.3 produces the minimum outlet air temperature for optimal cooling performance. Furthermore, perforations reduce airflow velocity at low supply ratios to enhance cross-channel heat and mass transfer and lower outlet temperature; at high supply ratios, they suppress evaporation and latent heat transfer, raising outlet temperature.