Monitoring ash fouling in power station boiler furnaces using acoustic pyrometry

Monitoring the real-time pollution status of the ash fouling produced by power station boiler furnaces and properly using the soot blower system of the boiler can significantly improve the safety and efficiency of such coal-fired boilers. This article examined the application of acoustic pyrometry close to the water-cooling wall by monitoring the flue gas temperature online and proposed a new clean factor. This article also studied the acoustic wave transmission rule near the water-cooling wall, and carried out experiments and research on a power station boiler furnace under a high-temperature operating environment. The studies showed that when boilers ran at a high temperature, the sound rays close to the water-cooling wall would bend toward the high temperature area inside the furnace due to the temperature gradient effect. The acoustically measured flue gas temperatures close to the wall were no longer a close approximation of the real flue gas temperatures of the water-cooling wall. After the sound rays were bent, the measured temperatures increased and would gradually increase as ash fouling began to accumulate on the wall. The clean factor ξ can be directly determined for real-time online monitoring of the condition of the local ash fouling at the water-cooling wall.