Design optimization and CFD evaluation of a volute swirl burner with central gas supply

The reasonable design and optimization can be useful tools to solve issues in several industrial applications. Since it is time-consuming and costly to do the experimental performance assessment using various equipments, computational fluid dynamics (CFD) with suitable models has been widely used due to the good agreement with experiments. This paper presented a universal design calculation method of a volute swirl burner with central gas supply. Then, CFD simulations with standard k–ε model, under non-reacting and reacting conditions, were carried out to verify the design feasibility. The mixedness of gas/air under non-reacting condition was evaluated from the perspective of normal distribution in statistics and checked by the designed excess air factor. A parametric study for various mixing section lengths and outlet diameters of the burner block was conducted to investigate their influence on the central recirculation zone and the temperature distribution. Simulation results show good agreement with empirical formula calculation. The gas and air have been mixed uniformly around the location that is 60 times of the gas orifice diameter. Additionally, an enlarged recirculation zone with increased recirculation strength can be formed with the increasing mixing length and block outlet diameter. In combustion simulation, the longer mixing length improves the flame stabilization but makes the combustion center move to the upstream of the burner due to the strengthened recirculation zone. The larger outlet diameter of the block stretches the flame and moves the high-temperature zone inside the flame to the downstream of the block wall.