Data Processing Method for the Measurement of Unburned Carbon in Fly Ash by PF-SIBS

In thermal power plants, the unburned carbon in fly ash is an important indicator of the boiler combustion efficiency. Online detection of unburned carbon content could benefit the optimization of the boiler operation. In this paper, a new scheme named as the particle flow-spark induced breakdown spectra was employed for the rapid measurement of unburned carbon content in fly ash. In order to improve the measurement accuracy, a series of data processing methods which mainly include spectral interference correction and quantitative analysis methods were specially carried out in this paper. The W 248.88 nm and Fe 254.60 nm lines were used as the correction lines to obtain the true C 247.86 nm integral intensity from the overlapping peak, and then the corrected intensity was substituted into the multivariate linear model to improve the measurement accuracy. The result shows that the regression coefficient (R-2) of the multivariate calibration model and the averaged absolute error are 0.987 and 0.15 wt %, respectively. The limit of detection of unburned carbon content determination is 0.28 wt %. These results are enough to meet the requirement of power industry standard and the commercial instruments for online analysis of unburned carbon in fly ash.