The carbon emission of the power industry accounts for more than 40% of the total carbon emission in China. Accelerating theimprovement of the accurate measurement and uncertainty assessment method of carbon emission of thermal power plants plays an important role in the fine supervision of carbon emission of the power industry. Considering that the measuring performance and accuracy ofthe concentration, flow and other measuring instruments installed on the power plant site may change after long-term operation, using thefactory accuracy of the meters to calculate the uncertainty cannot truly reflect the confidence level of the measurement. In this paper, animproved practical method for uncertainty assessment based on the periodic calibration results of the instruments was proposed. The methodwas used to evaluate the uncertainty of the online monitoring results of carbon emissions for a 660 MW power plant in Hubei Province,the contribution of uncertainty was analyzed, and optimization suggestions were proposed. The results show that the extended relative uncertainty of the carbon measurement results obtained by the direct measurement method is 8.282% (including factor k= 2, confidence level95%). With the exception of pressure, all other terms are dominated by class B uncertainty. Whether to consider the sensitivity coefficientand the choice of the evaluation method of Class B uncertainty will have a significant impact on the results. The main sources of carbonemission uncertainty are carbon dioxide concentration and flue gas flow measurement. The use of higher precision gas composition andflow measurement instruments, regular maintenance and calibration of measuring instruments, and optimization of measuring point layoutin the flue can help reduce the uncertainty.

黄辉(1986—),男,江西吉安人,高级工程师,硕士。E-mail:360688470@qq.com

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HUANG Hui,LIU Jun,CUI Hongbin,et al.Improved method for uncertainty evaluation of carbon measurement using fluegas direct measurement in thermal power unit[J].Clean Coal Technology,2024,30(8):42-49.