Numerical Study on Slag Flow in an Entrained-Flow Gasifier

A 2-D model for the slag flow, heat and mass transfer and solidification was developed to simulate the slag motion in the entrained-flow gasifier. Some assumptions were adopted to make the simulation practical and reduce the calculating time. The slag is treated as Newtonian fluid at the temperature above the temperature of critical viscosity, and solid below the temperature of critical viscosity. VOF model is used to capture the free surface between the syngas and slag layer. Numerical simulation of the slag flow in the gasifier is conducted by solving the equations of motion. The thickness of the slag layer, temperature distribution in the gasifier can be obtained. A series of simulations have been carried out to test the model. The effects of main variables on the flow, heat and mass transfer of slag on the refractory wall in the gasifier are analyzed numerically.