An anti-channeling flue tee with cycloidal guide vanes based on variational calculus

Abstract

In high-rise residential buildings, channeling in the flue between stories can spread pollutants and airborne diseases. To avoid this issue, it is necessary to use an airflow balance device, which will greatly increase the flow resistance. Based on a centralized exhaust shaft, this paper proposed a novel cycloidal guide confluence flue tee. The resistance characteristics of the flue tee were analyzed at different flow ratios and duct aspect ratios. The quantitative effects of the forward flow resistance decreased and those of the backward flow resistance increased after the guide vane was installed. The performances of the traditional tee and novel tee were tested and verified by performing full-scale experiments under the same duct aspect ratio and different flow ratios. The ranges of the decrease in forward resistance and increase in backward resistance were 44.07–196.97% and 4.30–171.20%, respectively. Under the same flow ratio and different duct aspect ratios, the ranges of the decrease in forward resistance and increase in backward resistance were 17.30–99.90% and 2.23–27.40%, respectively. The results of this work will provide a new perspective on resistance reduction and anti-channeling flue tee shape design in ventilation and air conditioning systems.