Research of Local Convection Heat Transfer of CO2 at Supercritical Pressures in a Vertical Tube

Convection heat transfer of supercritical pressure CO2 in vertical tube was investigated,the changes of physical property near critical point of supercritical carbon dioxide,the effect of inlet pressure,flow direction and imported Re on heat transfer coefficient.The results show that the physical property changes are very violently around the critical point,especially to the specific heat of carbon dioxide.It also concludes that inlet pressure of carbon dioxide have small influence on temperature of the thermal fluid,but larger influence on heat transfer coefficient.The effect of flow direction of thermal fluid on heat transfer coefficient is not too large.The effect of Re number on the heat transfer coefficient is more obvious.