Slagging analysis of a boiler using blended Zhundong coal

Abstract

Given the overload trip of a slag conveyor caused by slag falling in a critical coal-fired boiler using blended Zhundong coal， the diagnosis and analysis were carried out from five aspects of coal quality analysis， slag falling location， furnace soot blowing test， aerodynamics field and burner nozzle. The causes of slagging and its falling were deduced. Moreover， the furnace was shut down and inspected to verify the inference. The results indicate that the blended Zhundong leads to a moderate slagging tendency. Under the influence of deformation and blockage of the peripheral air nozzles of the burner， ash from combustion deposits as slag on the side water-cooled wall， accumulating into slags that， upon falling， trigger the overload trip of the conveyor. In view of the coal quality characteristics of the blended Zhundong coal， the paper proposes preventive measures from both operational and maintenance perspectives， providing insights for the operation of boilers facing similar situations.

Keywords

• blended zhundong coal
• slagging tendency
• conveyor overload
• burner burnout
• soot blowing adjustment