The alkali metals released during combustion of high alkali coals can easily lead to fouling and slagging of the heated surfaces of the furnace

affecting the safety of boiler operation

and it is significant to carry out the research of the slagging trend prediction. In this paper

a system for dynamic prediction of slagging trends in the furnace was developed by combining the slagging trend discrimination method based on ash composition analysis with flame emission spectroscopy. Firstly

a flame emission spectroscopy system was installed on the boiler to measure the gas phase alkali metal concentration in the furnace

and then a slagging trends test was carried out in the furnace exit area to obtain the deposition trend of the ash samples. Finally

a dynamic predictive system for predicting slagging in the furnace was developed and applied to the boiler by combining the slagging discriminating trends based on ash composition analysis of different coal samples and online monitoring of gas-phase Na concentrations

which can reflect the monitoring results of each parameter under the current combustion conditions in real-time

indicate the slagging trend in the current combustion state

thus enabling combustion adjustment instructions to prevent severe slagging.