Simulation of solid-fluid interaction in a supercritical water fluidized bed with a cold jet

Supercritical water fluidized bed reactor, where supercritical water serves as a fluidizing agent, is viewed as a promising way in hydrogen production. Water in cold jet experiences great physical fluctuations through injection under supercritical pressure. Severe temperature changes easily result in heterogeneous flow structures when cold jet injects entraining particles into the reactor. This paper develops an EMMS/energy model based on the energy-minimization multi-scale principles where energy balance equations are added. The effects of temperature on drag force due to simultaneous change of water density and viscosity are investigated. Validation is done with this new drag model incorporated into the Euler-Euler Two-Fluid model. Results show that temperature increase improves heterogeneous flow structure, especially in particles-dilute flow. EMMS/energy model can capture particle acceleration by thermal expansion of water in cold jet, which is responsible for clusters of particles.