Experiments on the Flow Characteristics of Gas Vortex Flowmeter under Different Medium Densities

To investigate the flow characteristics including meter coefficient,linearity,uncertainty and lower flow limit of the vortex flowmeter under different medium densities,tremendous experiments are performed on the gas flow calibration facility based on barotropic venturi nozzles.The flowmeter with a diameter of 50 mm was calibrated at the air density of 2.774 kg/m~3,3.619 kg/m~3,4.782 kg/m~3 and 5.987 kg/m~3 respectively by adjusting the pressure in conduits from 0.23 MPa to 0.5 MPa.The results demonstrate that the maximum relative error of meter coefficient under different densities is 0.405%,which verifies that the medium density has little influence on the meter coefficient of vortex flowmeter.It is also found that the lower flow limit extends downward with the increase of medium density.And the reason for this phenomenon is discussed.