Abstract
In this study, an experimental study on the spray cooling using liquid nitrogen (LN2) as the coolant was studied. Accordingly, an open-cycle experimental setup for cryogenic spray cooling was built. Investigation of spray cooling heat transfer performance on both plain and straight-grooved surfaces was carried out. The spray morphology was captured using the visual technique in the cryogenic system and the spray angles under different injection pressures were obtained. Additionally, a parametric study of heat transfer characteristics on the straight-grooved surfaces was carried out. The results have shown that the spray angle, at first, increases as with the inlet pressure, which is followed by a decrease. The straight-grooved surface significantly improved the spray cooling heat transfer compared to its plain counterpart by the maximum improvement rate of 64.2%. However, temperature uniformity was poorer. As the groove depth increases, the heat flux experiences increases at first, followed by a decrease. Finally, it was observed that the increase in groove width reduces the heat flux.
NSTL
Elsevier