Experimental study on slagging monitoring of pulverized coal-fired boiler based on slagging image

Abstract

Furnace slagging affects operation safety and efficiency of boilers. The accurate and timely use of a sootblower can prevent the furnace slagging deterioration. To instantaneously monitor the furnace slagging to guide the use of the sootblower， a slagging monitoring method in pulverized coal boiler based on slagging image is proposed. A cold state test bench for slag simulation is built in the laboratory. It is found through analysis that the accuracy of slagging monitoring can be improved by use of length-width ratios and brightness characteristics of slag blocks， and big data statistics， and that subtraction of two adjacent frames of pictures can help extract trajectories of the slag blocks. A real-time slag image monitoring system is equipped at the cold ash hopper of a 660 MW boiler to process the recorded slagging image， calculate the slag size， location， and brightness to grasp the rule of the slags in the furnace. The results show that when the load is lowered， the slag amount increases according to the real-time monitoring system， which is consistent with the oil pressure rise of the slag conveyor at the bottom of the furnace， which verifies the accuracy of the results of the monitoring system.

Keywords

• pulverized coal-fired boiler
• slag trajectory
• slag size
• slag location
• slagging monitoring