An Experimental Study And Numerical Simulation Of Heat Transfer To Supercritical Carbon Dioxide In The Double-Pipe

Based on the heat transfer of supercritical carbon dioxide flowing in the double- pipe cooled by water, the experiment research and numerical simulation of heat transfer characteristics are analyzed. The unconventional physical characteristic of supercritical carbon dioxide is also analyzed, which makes the supercritical carbon dioxide had a big difference in the heat transfer characteristics. Not only has provided the essential experimental data for analyzing the heat transfer mechanism, but this study also makes a further research of the heat transfer characteristics. The thesis does researches from some aspects as follows:Firstly, the main effects to supercritical carbon dioxide heat transfer are analyzed, including the change of specific heat and thermophysical properties of carbon dioxide in boundary layer. The specific heat, density, viscosity and heat conductivity of supercritical carbon dioxide are emphatically analyzed.Secondly, the change of mass flow rate, water flow, pressure and inlet temperature effect on the heat transfer characteristics and pressure drop is discussed. The carbon dioxide, water and total heat transfer coefficients are increased as mass flow rate increase. On the contrary, the heat transfer coefficient is increased as the pressure decrease. The inlet temperature change has hardly influenced on the heat transfer coefficient.Finally, the numerical simulation of heat transfer characteristics of supercritical carbon dioxide is displayed. It calculates the average heat transfer coefficient by simulating the temperature,the simulation value is compared with experimental result. In addition, the velocity field is also analyzed. Although there is some deviation, the heat transfer coefficient value has all reached peak near the critical temperature.