Yao Shun-chun, Chen Jian-chao, Lu Ji-dong, Shen Yue-liang, Pan Gang
Guang Pu Xue Yu Guang Pu Fen Xi. 2015 Jun;35(6):1719-23.
In coal-fired plants, Unburned carbon (UC) in fly ash is the major determinant of combustion efficiency in coal-fired boiler. The balance between unburned carbon and NO(x) emissions stresses the need for rapid and accurate methods for the measurement of unburned carbon. Laser-induced breakdown spectroscopy (LIBS) is employed to measure the unburned carbon content in fly ash. In this case, it is found that the C line interference with Fe line at about 248 nm. The interference leads to C could not be quantified independently from Fe. A correction approach for extracting C integrated intensity from the overlapping peak is proposed. The Fe 248.33 nm, Fe 254.60 nm and Fe 272.36 nm lines are used to correct the Fe 247.98 nm line which interference with C 247.86 nm, respectively. Then, the corrected C integrated intensity is compared with the uncorrected C integrated intensity for constructing calibration curves of unburned carbon, and also for the precision and accuracy of repeat measurements. The analysis results show that the regression coefficients of the calibration curves and the precision and accuracy of repeat measurements are improved by correcting C-Fe interference, especially for the fly ash samples with low level unburned carbon content. However, the choice of the Fe line need to avoid a over-correction for C line. Obviously, Fe 254.60 nm is the best
在燃煤电厂中，飞灰中的未燃尽碳（UC）是燃煤锅炉燃烧效率的主要决定因素。未燃尽碳与氮氧化物（NO(x)）排放之间的平衡强调了需要快速准确的未燃尽碳测量方法。采用激光诱导击穿光谱法（LIBS）来测量飞灰中的未燃尽碳含量。在这种情况下，发现碳线在约248nm处与铁线存在干扰。这种干扰导致碳无法独立于铁进行定量。提出了一种从重叠峰中提取碳积分强度的校正方法。分别使用铁的248.33nm、254.60nm和272.36nm谱线来校正干扰碳247.86nm的铁247.98nm谱线。然后，将校正后的碳积分强度与未校正的碳积分强度进行比较，以构建未燃尽碳的校准曲线，并评估重复测量的精密度和准确性。分析结果表明，通过校正碳 - 铁干扰，校准曲线的回归系数以及重复测量的精密度和准确性都得到了提高，特别是对于未燃尽碳含量较低的飞灰样品。然而，铁谱线的选择需要避免对碳谱线的过度校正。显然，铁254.60nm是最佳选择
