Optimization And Numerical Simulation Of Swirling Burner For Eliminating Boiler Slagging

The thermal power will continue to serve as the main force of the electric powerindustry for a long time due to the particularity of Chinese energy structure. The poorquality of the steam coal with high content of ash and sulfur is likely to form ashes on theheating surface and also causes abrasion and slagging. Slagging is a widespread and severeproblem in the operation of the coal-fired boilers which results in the reduction of theboiler’s output and efficiency, and even causes accidents.A600MW opposed coal-firing boiler was chosen to analyze and solve the slaggingproblem around the area of swirl burners during operation. The cold test was carried out tocheck the uniformity of velocity distribution of the burner outlet and to regulate the openingof the burner outer secondary air damper. It was found that the gas flow pattern at theburner outlet varied with the open degrees. The unreasonable distribution of air flow field atburner outlet was the main reason for the boiler slagging. The calculation results ofStandard and PRESTO! were analyzed and then compared with the gas flow pattern in thecold test. It showed that the result of Standard pressure interpolation method was consistentwith the result of the cold test.The schemes of changing only the outer water wall flaring or all flarings of the burnerwere analyzed through numerical simulation method. It was found that the former schemecan not only ensure the outlet air flow field of the burner closed, but also maintain adequaterecirculation zone. The flow field and temperature field of the boiler were studied to find amore reasonable transformation scheme.Finally, the boiler was reformed in the light of the scheme. The structure of outletairflow of burner was improved effectively and there was no outage as the result ofslagging. Therefore, the security and economic benefits of the boiler were significantlyimproved.