Conjugate Heat Transfer to Supercritical Water Wire-Wrapped Rod

摘要

This work presents a three-dimensional investigation of the conjugated heat transfer to supercritical water flowing upward in a square annular channel around a single wire-wrapped rod (WWR). The work aims at further understanding of the flow and heat transfer characteristics in the reactor core of the High Performance Light Water Reactor (HPLWR), which is strongly influenced by the effect of its wire spacer. In the numerical investigations a Local Heat Transfer Deterioration (LHTD) occurs at a high ratio of heat flux over mass flux (q/G), I.e. The wall temperature rises abruptly within the hotspot area. Once the heat conduction in the cladding material is taken into account (conjugate heat transfer), the maximum temperature on the rod surface is remarkably reduced with the elimination of the LHTD. The heat conduction of the cladding material also results in a better agreement between the prediction and measurement in terms of the mean surface temperature. However, it does not remove the hotspot completely. Additionally, turbulence model sensitivity studies are also presented in this paper. Results indicate that the SST k-ω model and the ω-based Reynolds Stress Models (ω -RSM) can give a better prediction in the wall temperature in comparison of the SSG model.