Diverging/converging small channel for condensation heat transfer enhancement under different gravity conditions

摘要

Diverging-shaped small channel is considered analytically aiming to further enhance condensation heat transfer inside channels. To fulfill heat dissipation requirements under varying-gravity conditions, effectiveness of the diverging small channel is also verified under different gravities. The refrigerant mass flow rate, total heat transfer area and thermal boundary conditions are fixed to investigate effect of channel shape. Smaller channel possesses better overall condensation performance, especially for small-gravity conditions. Diverging channel enhances local condensation heat transfer even with very small diverging angles. Overall condensation heat transfer becomes worse as diverging angle is relatively larger when channel size and gravity decrease. Converging-shaped small channel is therefore proposed and verified to effectively enhance the overall condensation heat transfer performance.