Flue gas flow is one of the key factors affecting the accuracy of carbon monitoring

and the complex flow field environment with uneven velocity distribution and changing with unit load is the main factor impeding the accurate measurement of flue gas flow. By taking a chimney inlet flue of a 660 MW unit in a power plant as the research object

the influence of the number of points and the layout of the process on measurement accuracy of the flowmeter with four different measurement principles was compared and analyzed based on numerical simulation results of the flue gas flow field. The results show that

the multipoint Pitot tube flowmeter has better adaptability to the complex flow field environment compared with the matrix flowmeter. When the number of measuring points is 28

the deviation of the matrix flowmeter is 1.54 times that of the multipoint Pitot tube flowmeter. The measurement accuracy of the light scintillation flowmeter is greatly affected by the elevation of the installation position

with the maximum deviation being 23.3 times the minimum deviation. This indicates that the light scintillation flowmeter has poor adaptability to complex flow field environments. The ultrasonic flowmeter can be installed obliquely and in multiple channels

with a more flexible and varied process layout

significantly improving its adaptability to complex flow fields. The dual-channel arrangement can control the deviation within ± 1.5%. The research results provide important theoretical basis and data support for the selection of flow meter equipment and process design

and have important theoretical research and engineering application value.