Influence of special water properties variation on the heat transfer of supercritical water flow around a sphere

Abstract

Supercritical water gasification (SCWG) technology shows a promising future due to its high efficiency and low emissions. Influenced by special water properties variation near the pseudocritical point, well-established heat transfer correlations are ill-suited for SCWG reactor design. To solve the problems caused by heat transfer, particle-resolved simulations were conducted to study the heat transfer characteristics of supercritical water (SCW) flow around a spherical particle, which served as a basic reacting unit. Through varying the temperature difference between the inflow and particle surface, heat transfer characteristics with different water properties variation tendencies were studied. Detailed analyses of the velocity and temperature boundary layers, and flow field around the particle were also presented to gain greater understanding. Furthermore, heat transfer characteristics under different pressures were studied. Based on the simulated results, a new correlation applicable for SCW flow around a sphere for the Reynolds number range 10–200 was obtained.