Effect of non-condensable gas on laminar film condensation of steam in horizontal minichannels with different cross-sectional shapes

• A 3-D numerical simulation of condensation with non-condensable gas is performed.
• The effects of non-condensable gas on the heat transfer characteristic are analyzed.
• The variation of heat transfer coefficient on different surfaces is displayed.

In the present study, a 3-D numerical simulation of laminar film condensation of steam in the presence of non-condensable gas is performed in horizontal minichannels with six cross-sectional shapes based on the volume of fluid (VOF) method. Mixture of steam and oxygen enters the channel with uniform temperature, while the inlet volume fraction of oxygen increases from 0% to 3%. It is shown that the existence of non-condensable gas results in significant reduction in the mass transfer rate from vapor to liquid along the interface in the axial direction. And then the heat transfer coefficient of condensation with oxygen is demonstrated to decline sharply compared with that of the pure vapor condensation.