R404A can replace R134a due to its stronger cooling capacity in CSC. In this paper, the influence of spray distance and duration on the dynamic heat transfer of the R404A spray cooling is quantitatively investigated through experiments to analyze the mechanism of heat transfer under different conditions. The results show that increasing spray duration can prolong the cooling time of the liquid film; thus, improving the cooling protection of the skin. The maximum surface heat flux qmax and maximum heat transfer coefficient hmax decrease as the spray distance increases. It is worth noting that qmax changes slightly before 30 mm. Thus, the distance of 30 mm may be regarded as the optimal spray distance that obtains the lowest minimum temperature and relatively high heat flux. Finally, the dimensionless heat flux correlation is proposed based on theoretical analysis.
Ran Yang, Xingang Zhu, Tao Yang, Zhifu Zhou, Bin Chen. Dynamic Heat Transfer on Skin Phantom Exposed to R404A Pulsed Spray Cooling[J]. Chinese Journal of Lasers, 2022, 49(5): 0507105