HWHJM Cross Sectional Flow Meter
Overview
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 is different, making it difficult to find a point that can represent the average flow velocity, and the actual wind speed distribution does not have a certain pattern to follow. The cross-sectional flowmeter divides a rectangular or circular pipeline into several equally sized small units, measures the flow velocity at the center point of each small unit, and then averages the sum of the flow velocities of all small units to obtain the average flow velocity of the entire large cross-sectional area, known as 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.
Instrument features
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 high 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 irregularly shaped cross-section pipeline) and the axial average flow velocity of the fluid passing through that area. Multiple structurally unique detection devices are installed inside the pipeline according to the different cross-sectional shapes and sizes of the measured pipeline. Obtain the average differential pressure through pressure equalization. The installation requirements are low. As long as there is a straight pipe section of 250-300mm, 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. At the same time, online blowing and maintenance are carried out through anti blocking blowing devices. Good 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:
Main technical parameters
★ Measuring media: air, boiler primary and secondary air and other media;
★ Pipes: Round pipes, rectangular pipes;
★ Scope of pipeline application: DN200 ∽ 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
Product Model Description
Pressure: A (≤ 1.0MPa), B (≤ 1.6MPa)
C(≤2.5MPa)、D（≤6.4MPa)
Material: C is carbon steel, S is 304 stainless steel, L is 316L stainless steel, Q is other
Inner diameter of the tested pipe (rectangular pipe)
Nominal Tongjing (circular pipeline)
Cross sectional airflow measurement device