Recent Development of Heat Transfer and Fluid Flow of Supercritical CO2 in Tubes: Mechanisms and Applications

With the advantages of low cost, excellent ability of heat and mass transfer and easy accessibility to the supercritical point, supercritical CO2 has been applied in many engineering devices recently. Because of the sharply-varying thermophysical properties near the supercritical point, heat transfer and flow behavior of supercritical CO2 in tubes become complex and have received a lot of research attention. The main purpose of this paper is to summarize the findings of the published works related to flow phenomena and heat transfer characteristics of supercritical CO2. Firstly, influence parameters related to boundary conditions of supercritical CO2 flowing in a smooth tube are introduced. Secondly, commonly-used turbulence and mathematic models dealing with internal flows of supercritical CO2 are summarized. Then, research works on geometric effects of design parameters, shapes and configurations are introduced. The practical applications of supercritical CO(2 )in recent years are presented. Finally, developments and future challenges of supercritical CO(2 )in tubes are analyzed and summarized. This paper provides basic knowledge of heat transfer and fluid flow mechanisms and related practical applications of supercritical CO(2 )in tubes.