Experimental investigation of comprehensive effects of surfactant and inclined mode on spray cooling heat transfer

Abstract

Spray cooling technology as a high heat flux cooling method is widely used to meet the increasingly cooling requirements, and the enhancement of spray cooling has gradually become a hot spot. In this study, three surfactants of AOS, CTAB and Tween20 with different concentrations were added into pure water to investigate their effects on spray cooling at low temperature range (≤100 °C) in a closed system. The three kinds of surfactants obviously improved the heat transfer performance, which had different optimum concentrations. The lowest mean surface temperature was obtained by CTAB with concentration of 200 ppm. The surface temperature non-uniformity of different surfactants spray was not improved, while the heat transfer deteriorated at high concentrations. In further study, the inclined mode method was used to alleviate the influence of bubble accumulation at high concentrations. The results showed that the inclined spray could significantly enhance the heat transfer capacity of the spray with surfactants and produce the optimum concentration point backward shift phenomenon. Moreover, the inclined spray mode showed a better promotion effect on spray cooling of surfactants with large surface tension.