NUMERICAL STUDIES FOR PYROLYSIS, GASIFICATION AND HEAT TRANSFER IN AN RDF FIXED-BED GASIFIER UNDER NON-PREMIXED CONDITIONS

摘要

As an attempt to complement experimental development of a solid waste gasifier at Korea Institute of Energy Research (KIER), a full three-dimensional computational model is developed for the complex two-phase flow based on porous medium representation of the solid stack. Compared to our previous work, new improvements in the model include the Lagrangian pyrolysis of solid material with the pyrolysis rate given as a function of the characteristic diameter of the solid waste material. Test simulations adopted the recent experimental modification in which oxidizer is directly injected into the interior of the solid stack of the waste material in order to facilitate oxidizer transport. The results demonstrate that the model properly reproduces the proper morphology of the solid stack and the temperature distribution for various feeding rates.