Influence of Exhaust Design on the Characteristics of Vortex Combustion

摘要

In the present paper, computational investigations on the characteristics of vortex flame behavior are carried out with non-premixed methane/air mixtures. Three chambers with different exhaust designs have been analyzed computationally. The effects of exhaust design (three types of exhaust design) on the flame shape, position, emissions and combustion efficiency are reported in this work. In Type 1, a tube has been considered as the exhaust of the chamber, in Type 2, the outlet flow has an opposite direction with inlet fuel, while in Type 3 the outlet flow makes a 90° angle with inlet fuel. The numerical results confirm that the obtained flame from vortex chamber Type 2, exhibits low emissions and high combustion efficiency compared to Type 1 and Type 3 due to the higher exhaust gas recirculation. As the exhaust gas temperature decreases, the combustion efficiency increases for a constant equivalence ratio. The predictions are compared with the measurements and revealed that K-ε RNG provided the best overall accuracy for all of the cases. However, this designed system simultaneously covers the merits of conservation of energy resource, air pollution control, as well as high efficiency portable devices.