Research On Meter Factor Of Gas Vortex Flowmeter And Gas Turbine Flowmeter

At present, the flow measurement plays an increasingly important role in trade settlement, process control, environmental protection, energy metering, and other various aspects of the national economy. Vortex flowmeter and turbine flowmeter are the most common speed-flowmeter. As new developed flowmeter, the application of them is relatively large around the world. The vacuum sonic Venturi nozzle test facility is used for flowmeter calibrate under normal pressure by domestic flowmeter manufactories. It is possible for the flow meter characteristic to change, if the meter is used under high pressure after normal pressure calibration, or high density after low density calibration.In order to study on the effect of the pressure change on the meter factor of the vortex flowmeter and turbine flowmeter, a lot of experiments were made on the critical flow nozzle gas flow standard facility at Process Measurement & Control Laboratory in Tianjin University.A gas vortex flowmeter and a gas turbine flowmeter were calibrated many times, as the fluid pressure change from 230 kPa to 500 kPa. The effect of pressure change on meter characteristics variation was analyzed. The effect of flow change, under same pressure, on meter factor was compared with that of pressure change under same flow.It was shown by the experimental results that the pressure change almost has no effect on meter factor of vortex flowmeter and turbine flowmeter, as fluid pressure varies from 230 kPa to 500 kPa. So, it was also shown that the performance of vortex flowmeter and turbine flowmeter is almost not affected by the fluid density change. This is consistent with the theory. With the pressure increasing, the measurable low limit of the vortex flowmeter decreases. Moreover, in the actual working conditions, the effect of flow rate change on meter factor is larger than that of fluid pressure change.