Theoretical analysis of annular upward flow in vertical narrow channel heated from one side

Abstract

A theoretical model of annular upward flow in vertical narrow channel heated from one side has been developed based on the fundamental conservation equations of the vapor core and liquid film. The experimental verification is performed to research on the flow boiling and heat transfer characteristics by setting up visualization platform with the channel that heated from one side. Through solving the closed equations of proposed model by numerical method, the film heat transfer coefficient for vertical two-phase flow is obtained. The results show a good agreement for the local heat transfer coefficient between theoretically calculated results and experimental data. Its mean absolute percentage error is 13.8%. With the applications of the proposed model, further study on the effects of several parameters (such as the cross-sectional width, mass velocity, and effective heat flux) on the liquid film thickness along the channel and radial velocity distributions in the liquid film are conducted.