Which aspects will affect the use of vortex street description

1. The measurement range of the vortex flowmeter is large, generally 10:1, but the lower limit of measurement is limited by many factors: Re>10 000 is the most basic condition for the operation of the vortex flowmeter, in addition to it, it is also subject to vortex energy. Restriction, if the medium flow rate is low, the intensity and rotation speed of the vortex are also low, and it is difficult to cause the response signal to be generated by the sensing element, and the vortex frequency f is also small, which also makes signal processing difficult. The upper limit of the measurement is limited by the frequency response of the sensor (such as the magnetic sensitivity type generally does not exceed 400 Hz) and the frequency limit of the circuit. Therefore, the flow rate range must be calculated and calculated according to the flow rate of the fluid. The use of the on-site environmental conditions is complex, in addition to the conditions of the ambient temperature, humidity, atmosphere, etc., also consider electromagnetic interference. In the case of strong interference such as high-voltage power transmission stations, large-scale rectification stations, etc., magnetic-sensitive, piezoelectric stress-type instruments cannot work normally or cannot be accurately measured.
2. Vibration is also a big enemy of this type of instrument. Therefore, care should be taken to avoid mechanical vibrations, especially the lateral vibration of the pipe (perpendicular to the pipe axis and the vertical vortex generating body axis). This effect cannot be suppressed and eliminated in the design of the flowmeter structure. Since the vortex signal is equally sensitive to the flow field, it is not suitable to use the length of the straight pipe section to ensure the necessary flow conditions for stabilizing the vortex street. Even a capacitive or ultrasonic type with high vibration resistance ensures that the fluid is a fully developed one-way flow and cannot be ignored.
3. The temperature of the medium also has a great influence on the performance of the vortex flowmeter. For example, the pressure stress type vortex flowmeter cannot be used for a long time at 300 °C, because its insulation resistance will drop from 10 MΩ to 100 MΩ at normal temperature to 1 MΩ to 10 KΩ, and the output signal will also become smaller, resulting in deterioration of measurement characteristics. For this purpose, a magnetic sensitive or capacitive structure should be used. In the measurement system, the sensor and the converter should be separated and installed to avoid long-term high temperature affecting the reliability and service life of the instrument.