Thermal performance of a psychrometric cooling system using cyclone fluid dynamics.

Indirect evaporative cooling is a technology that can be used sustainably to replace traditional cooling systems using thermodynamic compression cycles, especially in tropical countries like Brazil, which have many regions with hot climates and low relative humidity. These meteorological aspects favor the simultaneous transfer of heat and mass, allowing the thermal cooling effect characteristic of evaporative cooling processes. Thus, this paper investigates the performance of a sustainable air cooling system by combining the psychrometric effects of warm, dry air with the flow features inside a cyclone covered by a layer of a fabric moistened with water. Fluid dynamic simulations previously indicated temperature decreases of up to 12.2 K between the feed and overflow streams of the cyclone. In addition, temperature contours showed that the fluid dynamics of the cyclone provide instantaneous thermal exchange between the walls and the internal fluid. These results directed the study to execute an experimental design using the response surface methodology to evaluate the influence of some variables in the process. The decrease in air stream temperature ranged from 3.9 to 13.1 K, with relative humidity and ambient temperature being the most significant variables. The results also indicated that water consumption to maintain the fabric wet is relatively low since 16·10-3 kg of liquid is required to cool 1 m³ of air flowing through the cyclone. [Display omitted] • High inlet temperature and low relative humidity provided maximum thermal gradients. • Within 0.75 s, in average, the system provided a thermal reduction of up to 13 K. • The thermal efficiency of the wet-bulb for the new system varied from 54.8 to 67.8 %. • Dimensionless numbers for psychrometric cooling system showed a linear behavior. [ABSTRACT FROM AUTHOR]