Numerical Simulation of Supercritical Water Oxidation with a Transpiring Wall Reactor

Abstract

Transpiring wall reactor is a promising engineering solution to corrosion and salt precipitation for the technology of supercritical water oxidation. Characteristics of flow conditions and species concentrations in the reactor and around the transpiring wall are hardly accessible to measurements. So a computational fluid dynamic model of the transpiring wall reactor was developed. The influence of different operating parameters on the temperature distribution and species distribution, especially the temperature near the transpiring wall, were investigated. Feed mass flow, feed flow temperature and ethanol concentration has a strong influence on the temperature of reactor. Higher feed mass flow, feed flow temperature and ethanol concentration are beneficial to the destruction of ethanol, but it reduces the protection of upper transpiring wall. The optimum feed flow for the reactor is between 0.002 and 0.003kg/s at 380 ℃, Transpiration intensity has minimal influence on the temperature, but lower transpiring flow temperature is beneficial to protection of the porous wall. Upper branch transpiring water of 300 °C provides a subcritical protective film to prevent corrosion and salt precipitation.