Study of the Monitoring of the Local Ash Fouling on the Water Walls of a Utility Boiler Based on the Acoustic Pyrometry

To solve the difficulty in monitoring the ash fouling on water walls of a boiler,introduced was a cleaning factor to transform it into an acoustic pyrometric problem. On this basis,an on-line system for monitoring the ash fouling on water walls of a boiler was developed and an experimental study was performed on a domestic 300 MW boiler. As a result,the flue gas temperatures along the acoustic line close to the water walls were obtained and the temperature fields in the sections of the furnace in the boiler were rebuilt. The research results show that the new cleaning factor can be used to monitor the local ash fouling conditions of the water walls. Due to the curvature effect of the sound wave,the average flue gas temperature measured along the acoustic line is about 130 ℃ higher than that on the surface of the water walls facing the flame. Any change in the temperature of flue gases close to the water walls can be used to represent that in the water wall temperature. The temperature field thus rebuilt can be used to real-time and accurately observe the movement of the flame center in the furnace,thus the foregoing can offer important reference for monitoring ash fouling and intelligent soot blowing in boilers.