The working principle of a cross-sectional flowmeter is that due to the lack of sufficient straight pipe sections, the flow velocity at each point on the cross-section of the pipeline varies, making it difficult to find a point that can represent the average flow velocity. The actual distribution of wind speed does not have a certain pattern to follow. We divide the size and cross-sectional area of rectangular or circular pipelines into several small units with the same area. The cross-sectional flowmeter measures the flow velocity at the center point of each small unit, and then the flow velocity of all small units is averaged to obtain the average flow velocity of the entire cross-sectional area, which is the velocity area method. The more the unit area is divided, the more accurate the flow velocity measured by the cross-sectional flowmeter. The cross-sectional flowmeter is designed based on this principle and has been proven in practical applications.
Purpose and characteristics: The load, coal powder quantity, and air distribution of coal-fired boilers in power plants need to be monitored and automatically controlled online to ensure reasonable primary and secondary air distribution, uniform air velocity in each air duct, stable combustion of the boiler, and improved efficiency. This is essential for technical analysis and economic accounting of the production process. The cross-sectional airflow measurement device is a new type of flow sensor designed and manufactured based on the measurement principle of velocity area method. It measures the cross-sectional area of a closed pipeline (circular, rectangular, or other irregular cross-section pipeline) and the axial average flow velocity of the fluid passing through that area, based on
Due to the different cross-sectional shapes and sizes of the tested pipelines, multiple structurally unique detection devices are installed inside them. Obtain the average differential pressure through pressure equalization. Low installation requirements, as long as there is a straight pipe section of 250-300m, it can be installed with self rectifying function, which is not affected by irregular fluids or even multi-directional rotating airflow. The pressure loss is small, only 10% of that of the wing wind measurement device. Its flow coefficient is stable and does not require on-site calibration. Online blowing and maintenance can be carried out through anti blocking blowing devices. Good long-term stability, wide applicability, simple structure, easy to operate, and easy to troubleshoot. There is no need for a straight pipe structure. The structure of the cross-sectional air volume measuring device is shown in the following figure:

Technical parameters:

Measurement media: air, boiler primary and secondary air, and other media;
Pipes: circular pipes, rectangular pipes;
Scope of pipeline application: DN=200~6000mm B × H=200 × 300~3000 × 4000mm;
Basic error limit: ± 1.0%;
Nominal pressure: PN ≤ 6.4MPa;
Fluid temperature: t ≤ 450 ℃;
Accuracy level: 1.0 level, 1.5 level, 2.5 level