1. School of Mechanical and Energy Engineering, Tongji University, Shanghai 201804, China
2. China Special Equipment Inspection and Research Institute, Beijing 100029, China
Abstract：A formula for calculating the flue gas recirculation rate is derived based on a chemical reaction balance equation with constant gas components and concentrations. A dual oxygen method for measuring flue gas oxygen concentration and flue gas-air mixture oxygen concentration in gas boilers is proposed. In order to quantify the quality of the measurement results, the uncertainty of the dioxygen method is assessed based on the GUM method in national standards, and instrument selection guidance is presented based on uncertainty requirements. It is found that when the flue gas oxygen concentration measurement result is 1.91% and the mixed gas oxygen concentration measurement result is 18.64%, the flue gas recirculation rate R calculated by the dual oxygen method is 13.45% with an extended uncertainty of 1.56%. The uncertainty of the mixed gas oxygen concentration measurement has a significant impact on the extended uncertainty of the dioxygen method. When measurement instrument is selected, the extended uncertainty of a mixed gas oxygen concentration measurement instrument can be less than the extended uncertainty of the flue gas oxygen concentration measurement instrument.
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2022, Vol. 43 
