Study on boiling heat transfer characteristics of R410A outside horizontal tube under swaying condition

Abstract

AbstractTo investigate the boiling characteristics of flow outside the R410A tube under swaying conditions, this article conducts numerical simulation and experimental research on the flow boiling heat transfer of R410A outside a horizontal tube. The results show that when the swing frequency increased from 0.2 to 2 Hz, the sway amplitude is 0.03 m, the heat flux on the inner wall of the runner remains unchanged, and the mass flow rate increases from 85 to 170 kg/(m2·s), which makes the heat transfer coefficient of the working fluid in the annular area increases significantly. Keeping the inlet mass flow rate unchanged, the heat flux on the inner wall of the flow channel increases from 25 to 35 kW/m2, the heat transfer coefficient of the working fluid in the annular area has also improved, but under high heat flux conditions, the working fluid is evaporated and dried, its heat transfer coefficient increases less than in low heat flux conditions. When the sway amplitude increases from 0.02 to 0.07 m, the sway frequency is 0.2 Hz and 2 Hz respectively, and the heat transfer coefficient of the working fluid shows a downward trend as a whole. The studies provide a reference for heat exchanger design suitable for offshore swaying conditions.