On-line monitoring of ash fouling for air pre-heaters in coal-fired power plant boiler

Air pre-heater of coal-fired power plant boiler is an important piece of engineering equipment, which is designed to heat air before combustion in furnace with the primary objective of increasing the thermal efficiency of the boiler. This paper presents a mathematical model of heat exchange, which allows for the on-line monitoring of ash fouling in air preheater. The model is built using dynamic heat balance method, in which the cleanliness factor is used to characterize the fouling level. The ash fouling model is validated by using the actual data of a 300MW power plant boiler. The validation results show the effectiveness of the proposed method. It can be used for the soot blowing optimization in most coal-fired power plant boiler with air preheaters, not requiring additional special instruments and complex computing systems.