APPLICATION OF DIFFERENT TURBULENCE MODELS FOR IMPROVING CONSTRUCTION OF SMALL-SCALE BOILER FIRED BY SOLID FUEL

Due to the rapid progress in computer hardware and software, Computational Fluid Dynamics (CFD) became a powerful and effective tool for implementation turbulence modeling in defined combustion mathematical models in the complex boiler geometries. In this paper the commercial CFD package, ANSYS FLUENT was used to model fluid flow through the boiler, in order to define velocity field and predict pressure drop. Mathematical modeling was carried out with application of Standard, RNG and Realizable k-e turbulence model using the constants presented in literature. Three boilers geometry were  examined with application of three different turbulence models with variants, which means consideration of 7 turbulence model arrangements in FLUENT. The obtained model results are presented and compared with data collected from experimental tests. All experimental tests were performed according to procedures defined in the standard SRPS EN 303-5 and obtained results are presented in this paper for all three examined geometries. This approach was used for improving construction of boiler fired by solid fuel with heat output up to 35 kW and for selection of the most convenient construction.