Mitigating Salinity Effects: Thermal Performance Analysis of a Packing-Free Shower Cooling Tower for Seawater Application Using a Comprehensive Droplet-Based Model

This study addresses the operational challenges of conventional packed cooling towers in seawater applications, where salt deposition and blockage significantly impair performance. A packing-free shower cooling tower (SCT) utilizing droplet-based heat and mass transfer is proposed as a robust alternative for high-salinity applications where conventional packed towers are prone to fouling and blockage. A comprehensive numerical model was developed and validated experimentally, showing a maximum error of less than 6% in predicting outlet water temperature. The analysis demonstrates that increasing salinity markedly reduces cooling efficiency—for instance, at threefold concentration (S ≈ 57.96 g/kg), efficiency decreased by 5.59% in summer and 4.91% in winter compared to freshwater, due to reduced vapor pressure and inhibited evaporation. However, elevating the inlet water temperature and air-to-water ratio partially counteracted these effects by enhancing evaporative and convective transfer. Larger droplet diameters also adversely affected performance, with cooling efficiency dropping from 75.87% (1 mm droplets) to 28.92% (3.5 mm droplets) in freshwater summer conditions. Notably, seasonal variations influenced the magnitude of salinity-related performance loss, with winter operations exhibiting less degradation. These findings provide critical insights and a reliable predictive tool for the design and optimization of high-salinity cooling systems.