Strömungssimulation von Müllverbrennungsanlagen in Teillastbereichen

A CFD-analysis of a process plant is often limited to only one simulation of the plant's operating point. Experiences with plants (waste incinerators) working with inhomogeneous fuel (such as municipal waste) have shown that this approach does not yield sufficient informations on the process and the reliability of the incinerator. This is why further simulations have to be conducted beyond the operating point. In our case the corners of the guarantee field in the firing diagram were chosen to analyze the quality of the construction under the corresponding boundary conditions. In this paper, a geometry of an existing waste incinerator was examined by carrying out the above mentioned simulations at the corners of the guarantee field. To detect possible draw-backs of the construction, emphasis was put on operating conditions with partial loads. The results underlined the need of optimization strategies for geometry and/or boundary conditions during operation as adverse operating conditions were observed. One starting point to improve the operation of the incinerator is to uncouple the two elementa-ry functions of the secondary air. It supplies oxygen for the combustion and has to generate turbulence to improve the mixing which could be achieved by independent additional jets of recirculated flue gas or pressurized steam alternatively.