Numerical analysis of the effect of conical turbulators to heat transfer performance of a liquid fuelled boiler

In this study, increasing the efficiency of liquid fuelled smoke tube boilers used for domestic heating was researched. In this context, turbulators with conical geometries placed to smoke tubes of boiler and effects on flame structure and heat transfer were investigated numerically. Calculations were carried out at two dimensional axisymmetric conditions and Fluent was used as the computational fluid dynamics software. In all cases, the standard k-ε model was used for modeling the turbulent flow and the species transport model was used for modeling the combustion. Based on the results of these turbulators were evaluated for each condition. Besides, temperature and stream function distribution and pressure drop were investigated according to the arrangement of turbulators and which number of turbulator would be the most appropriate at boilers was discussed. Increasing the number of turbulators from zero to three decreased the exhaust temperatures 15 K from 365 K to 350 K, and consequently the efficiency of the boiler was increased. Yet the turbulators inserted into smoke tube increased the pressure losses insignificantly from 20 to 23.5 Pa.