Critical heat flux prediction model for flow boiling on micro-pin-finned surfaces

Abstract The critical heat flux (CHF) of flow boiling can be obviously improved by the micro-structured surface which promotes the liquid supply by the capillary wicking effect. In this study, a new phenomenon of bubble behavior for flow boiling on micro-pin-finned surfaces was observed, based on which a theoretical model to predict the CHF of flow boiling on micro-pin-finned surfaces was proposed. Both the effect of liquid sublayer under the vapor blanket and the capillary wicking effect of the surface structure were taken into consideration. To verify the model, the CHF of flow boiling for different surface structures, flow velocities and inlet liquid subcoolings were tested. The model showed good applicability for flow velocity less than 1 m/s with the mean absolute error of 13.9%.