Experimental investigation of spray cooling performance in non‐boiling zone on rough superhydrophilic/hydrophobic surfaces

Spray cooling has a wide application prospect in the heat dissipation of high-power devices due to its excellent heat transfer performance and low demand for working medium. In this work, an experimental setup was built to investigate the heat transfer characteristics of the deionized water spray cooling in the non-boiling zone. Copper surfaces with different roughness conditions, as well as superhydrophilic/hydrophobic surfaces, were introduced to study the influence of surface property on cooling performance. Results show that no prominent change in heat transfer coefficient occurs due to the variation of roughness in the working conditions discussed. Furthermore, the superhydrophilic/hydrophobic surfaces experience a maximum reduction of 9.6% and 9.2% in heat transfer coefficient, respectively, compared with that of a smooth surface.