The effects of thermal properties on interphase heat transfer between supercritical water-particle flow

The interphase heat transfer of particle flow is of significant importance. This work employed the particle-resolved direct numerical simulation to calculate the interphase heat transfer of supercritical water (SCW)-particle flow. In particular, the influences of complex variations in nonlinear physical properties of SCW has been considered. The results reveal the opposing effects of nozzle effect and particle interaction on the heat transfer. The large Prandtl number (Pr) in critical zone predominantly enhances heat transfer. However, the increase in density weakens the influence of nozzle effect, diminishing the enhancing effect of larger Pr. The strength of interphase heat transfer varies under different conditions, and the influences of variations in density and Pr distribution are also different. As a result, the correlations for the normalized heat transfer coefficient N with varying constants are established. Furthermore, based on the differing dominances of nozzle effect and particle interaction, an appropriate Nusselt number (Nu) correlation for heat transfer of particle flow is developed for most cases. The correlation for SCW-particle flow interphase heat transfer Nu can be obtained by coupling the Nu and N correlations. It shows good predictive performance.