Influence of horizontal swing angles of secondary air out from orifices in tangential circles on a 670 t/h boiler

To decrease NO_x emission of a 670 t/h boiler in a power plant, the technology of retrofitting all common nozzles of burners to nozzles of Horizontal Bias Pulverized Coal Combustion Burners and orifices of the top secondary air in the bottom group of burners, the middle and the top secondary air in the middle group of burners horizontally swinging has been put forward. Therefore, the technology combines horizontal bias combustion and secondary air horizontal swing. Due to the scaling criteria, industrial experiments of aerodynamic field were done in the boiler. The imaginary circle rotational direction of the secondary air was changed from clockwise to reversal clockwise at No.1 and 3 corners, and four horizontal swing angles of orifices of the secondary air were taken. The experiment shows that diameters of tangential circles between the front and the rear walls increase from 7200 mm to 12080 mm and those between the left and the right walls from 8100 mm to 12100 mm with the increase of swing angles. The cold state experimental results provide the fundament for reacting flow experiment and numerical simulation in the future.