Numerical investigation of optimal geometry parameters for ejectors of premixed burner

Abstract

An ejector of low NO_x burner was designed for a gas instantaneous water heater in this work. The flowing and mixing process of the ejector was investigated by computational fluid dynamics (CFD) approach. A comprehensive study was conducted to understand the effects of the geometrical parameters on the static pressure of air and methane, and mole fraction uniformity of methane at the outlet of ejector. The distribution chamber was applied to balance the pressure and improve the mixing process of methane and air in front of the fire hole. A distribution orifice plate with seven distribution orifices was introduced at the outlet of the ejector to improve the flow organization. It is found that the nozzle exit position of 5 mm and nozzle diameter d >1.3 mm should be used to improve the flow organization and realize the well premixed combustion for this designed ejector.

Keywords

ejector / computational fluid dynamics (CFD) / burner / distribution orifice / premixed combustion

References

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