Numerical Investigation of Heat and Mass Flux Effects on Heat Transfer Characteristics of Supercritical Water in an Upward Flow Vertical Tube

In the present work, the heat transfer characteristics of supercritical pressure water are numerically investigated in an upward flow vertical smooth tube. The numerical simulations are carried out by using Ansys-Fluent solver. The objective of the present work is to investigate the effect of heat flux and mass flux on heat transfer characteristics in supercritical water. In order to perform numerical simulation, experimental data of Mokry et al. [2] is considered. Various simulations were carried out for the inlet parameters of temperature 350°C, pressure 240bar; heat flux values ranging from 190 to 884kW/m2 and mass flux values ranging from 498 to 1499kg/m2s. Based on the available parameters of heat flux and mass flux, they are segregated as groups with heat flux to mass flux ratios of 0.39 and 0.67. According to computational data, the heat transfer enhancement and heat transfer deterioration phenomenon of supercritical water were analyzed and based on the comparison with experimental data; their occurrence and mechanism were addressed.