Abstract:
Supercritical Cooled-Water Reactor (SCWR) which is planned to be deployed by 2030 derives its concept from Light Water Reactors (Boiling Water Reactor (BWR), Pressurized Water Reactor (PWR) and Fossil Fired Coal Plant but with a simpler design. Due to the strong variations of density at supercritical pressure, the SCWR is likely to inherit some of the issues related to the LWR’s in terms of heat transfer (e.g. thermal crisis). This research was undertaken in order to better understand the phenomena of heat transfer as applied to SCWR and also to test the applicability of Reynolds-Average Navier-Stokes (STAR-CCM+ CFD code). Kim’s et al., (2005) data which employs supercritical CO2 as a simulant of water at 8 MPa was used to test the applicability. The computational simulation by STAR-CCM+ on the prediction of a 2-D axisymmetric heat transfer of carbon dioxide at supercritical pressure flowing upward through heated cross-section of a circular tube was performed with six (6) low-Reynolds number models; -epsilon AKN, EB, standard low- Re and V2F with two -ω turbulence models; SST and standard Wilcox with low y+ wall treatment. The results of heat fluxes of 20, 23, 30 and 40 kW/m2 and mass flux of 314 kg/m2s were compared to the experimental data of Kim et al., (2005). The Standard low- Reynolds turbulence models were seen to have better capabilities to predict the heat transfer behaviour of supercritical CO2 as observed in the experiment. The -ω models did not perform favourably in the prediction of heat transfer deterioration. The V2F turbulence model performed better than the other models quantitatively when compared to the experimental data. The results of the simulation has been found to be able to reproduce the general features exhibited in the experimental data even though they over predicted the observed heat transfer deterioration both quantitatively and qualitatively.
