The Development and Investigation of the Diffusion-Stabilizing Burner with the Niche

Abstract

The article presents the results of researches of the development and field tests in bench conditions of the microdiffusion stabilizer burner device of a rectangular slot type with a niche deepening along the entire perimeter of the burner. The air passes through a rectangular slot, gaseous fuel for combustion is supplied to the recirculation zone through a system of holes in the end wall of the stabilizer. On the side of the output end of the stabilizer, there is a niche deepening. As studies have shown, the niche deepening is an additional source of stabilization and intensification of torch burning. The experimental data and calculated dependences on the stabilization of the torch in the modes of “poor” disruption are obtained. It is shown that the stable operation of the burner on the lean limit expands – the coefficient of excess air increases with an increase in the width of the stabilizer, the diameter of the gas distribution holes, the coefficient of shading of the burner and air temperature, as well as with a decrease in the speed of the air flow. The research results showed that “rich” flame failure – flame failure with a gradual increase in gas flow occurs at air excess ratios less than unity. This ensures the reliable operation of the burner at the calculated operating modes with respect to the coefficient of excess air a = 1.15 – 6.0 and the air flow speed Wp = 12.0 m/s. A dependence was obtained that determines the influence of regime and design factors on the characteristics of a rich flare failure. The sustainability of the burner operation on the rich limit increases – the coefficient of excess air decreases, with an increase in the width of the stabilizer, the shading coefficient of the burner, air temperature and a decrease in air velocity. The experimental data and calculated dependences on the length of the combustion zone in the burner device are obtained. It was established that at the calculated coefficient of excess air a = 2.0 and higher coefficients, complete combustion of fuel occurs on the length of the combustion space X = 1000 mm. The relative length of the flame decreases when the shading coefficient of the burner and the air temperature increases. Measurements of harmful nitrogen oxides showed that the maximum content of oxides is observed at the coefficient of excess air a = 1.0 and is 125 mg/m3, which is less than the limit values which allowed by regulatory documents.