Impact of geometrical surface modification on spray cooling heat transfer performance with liquid nitrogen: An experimental investigation

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.

Automated summary

This study investigated the spray cooling using liquid nitrogen as the coolant. Results showed that the straight-grooved surface significantly improved the spray cooling heat transfer compared to the plain surface, but temperature uniformity was poorer.