SCANDINAVIAN BAFFLE BOILER DESIGN REVISITED

The aim of this paper is to examine whether the use of baffles in a combustion chamber, one of the well-known low-cost methods for the boiler performance improvement, can be enhanced. Modern day tools like computational fluid dynamics were not present at the time when these measures were invented, developed, and successfully applied. The objective of this study is to determine the influence of location and length of a baffle in a furnace, for different mass flows, on gas residence time. The numerical simulations have been performed of a simple Scandinavian stove like furnace. The isothermal model is used, while air is used as a medium and turbulence is modeled by realizable k-epsilon model. The Lagrange particle tracking is used for the residence time distribution determination. The statistical analysis yielded the average residence time. The results of the computational fluid dynamics studies show that influence of baffle positions, dimension, and flow rates can decrease residence time even 17% but also increase it up to 13%. Vertical position of the baffle is the most important factor, followed by the length of the baffle, while the least important showed to be the mass flow.