Study on the heat transfer characteristics of dry ice sublimation spray cooling with dual nozzles

Abstract

A new dual-nozzle dry ice sublimation spray cooling numerical calculation model was designed to address the thermal management of high heat load electronic devices. A numerical test was conducted using the CFD two-phase flow solver to investigate the dry ice sublimation spray cooling process in gas-solid two-phase flow. The effects of different spray tilt angles, nozzle inlet velocities and dry ice occupancy ratios on the heat transfer characteristics of dual-nozzle variable-angle dry ice sublimation spray cooling were investigated. The results show that the dry ice sublimation spray cooling performance increases with increasing nozzle inlet velocity and dry ice ratio and decreases with increasing nozzle inclination under the conditions of constant height of the nozzle center from the upper surface of the heat source and heating power of the simulated heat source. The dry ice phase distribution on the upper surface of the heat source was higher when the dry ice percentage was closer to the longitudinal symmetry axis. The temperature of the inner peripheral zone on the upper surface of the heat source was lower than that of the direct spray zone, and the cooling heat flow density and heat transfer coefficient were higher than that of the direct spray zone. In the transverse symmetry axis of the heat source's upper surface, the heat transfer coefficient distribution showed an "M-like" curve. The average temperature of the surface of the heat source was 285 K, and the heat transfer coefficient was 18116.24 W/(m2-K) when the nozzle inlet velocity was 16 m/s, the proportion of dry ice was 40 percent, and the nozzle tilt angle was 30º.