Numerical simulation and experimental investigation of a premixed cylindrical burner with gas mixing system using in condensing boiler

This paper focuses on a numerical simulation and experimental investigation of premixed cylindrical burner with gas mixing system. These burners are used in condensing boiler. Performance assessment of the burner and mixer at a power of 11 kW is the main purpose of this paper; also, the two-stage methane-air mechanism have been employed for combustion kinetic. Moreover, Short length of flame, high radiation and low emissions are among the most important and notable characteristics of these types of burners. To measure flame and burner surface temperature experimental tests have been conducted. Moreover, simulation results have been validated by experimental findings. Obtained results are in good agreement with experimental findings. In addition, maximum 14% difference have been found between experimental and numerical results. Results indicated that by increasing the equivalence to the stoichiometric ratio, maximum flame temperature and NOx emissions has been increased. Moreover, in this type of burners radiation is the dominant heat transfer mechanism at below 2.5 cm around the burner. The equivalence ratio at the range of 0.75 to 0.85 has been selected as the operating condition of the burner according to the temperature limitation and pollutant production in burner.