Sensitivity analysis and optimization of heavy oil burner for drum dryer in asphalt mixing plant based on numerical simulation and orthogonal experimental method

As the core equipment of drum dryers, heavy oil burners have been widely used in the asphalt mixing plant. However, the heavy oil burners in the drum dryers have the disadvantages of insufficient combustion and high NOx emission levels. To improve the combustion performance and reduce NOx emissions, the order and optimal combination of geometric parameters for heavy oil burners were determined by the numerical simulation and orthogonal experimental method. In addition, a comprehensive performance index (CPI) was proposed based on entropy theory to evaluate the overall performance of the burner. The results show that the order of geometric parameters of the heavy oil burner is different with different indicators. However, the number of oil spray nozzles has the greatest impact on the burner performance. The geometric parameters of the burner significantly affect the outlet CO concentration. A suitable burner structure parameter can reduce the amount of NOx emissions by 33.7 %. Among the 9 cases, case 8 has the highest CPI, with flame length, outlet CO concentration, and NOx concentration of 4.6 m, 19.5 ppm and 242 ppm, respectively. To achieve the highest CPI for the burner, the optimal geometric parameters of the diameter of holes on the porous plate, angle of swirl blades, number of spray nozzles, and diameter of the porous plate are 20 mm, 45 degrees, 7, and 80 cm, respectively.