Knowledge of Vortex Flow Meter | Working Principle of Vortex Flow Meter

『Knowledge of vortex flowmeter』Related information(v cone flow meter|rotary gas meter|gallon meter|gear meter|metal tube rotameter|glass tube rotameter|nutating disk meter|transit time ultrasonic flow meter|wedge flow meter|pd meters|hydraulic flow meter|ultrasonic water flow meter|water flow meter|air flow meter|magnetic water flow meter|oxygen flow meter|gas flow meter|argon flow meter|air velocity meter|gasoline flow meter|fuel flow meter|ultrasonic water meter|digital water meter|nitrogen flow meter|solid flow meter|Oxygen tank flow meter|digital water flow meter|diesel fuel flow meter|steam flow meter|02 flow meter|compressed air flow meter|oil flow meter|liquid flow meter)

1. Working principle of gas vortex flowmeter

The working principle of gas vortex flowmeter is based on the Karman vortex phenomenon, and flow measurement is achieved by detecting the vortex frequency. The specific principle and key points are as follows: The formation of Karman vortex street is achieved by setting up non streamlined vortex generators (such as triangular columns) in the fluid. When the fluid passes around the generator, regular vortices are alternately generated on both sides, forming Karman vortex street. The vortex column is asymmetrically arranged downstream of the generating body, and its frequency of generation is related to the fluid velocity. The relationship between vortex frequency and flow velocity is determined by the Strouhal number $Sr $, where $f=frac {Sr cdot U_1} {d}=frac {Sr cdot U} {m cdot d} $where $U_1 $is the average flow velocity on both sides of the vortex generator (m/s); $d $is the width of the inflow surface of the generating body; $m $is the ratio of the area of the arch on both sides of the body to the cross-sectional area of the pipeline; $Sr $is a dimensionless Strouhal number, which is related to the shape of the generator and the Reynolds number of the Wangxiong nucleus $Re-D $. Within the Reynolds number range of Re-D=2 times 10 ^ 4 sim 7 times 10 ^ 6, $Sr $can be considered a constant, indicating stable operation of the flowmeter. The calculation of volumetric flow rate in a pipeline is derived from the vortex frequency $f $: $$q-v=frac {pi D ^ 2 cdot U} {4}=frac {pi D ^ 2 cdot m cdot d cdot f} {4 cdot Sr} $, where $D $is the diameter of the body. The instrument system of the flow meter has a trapped number of K (pulses/m3) defined as:$$ K = frac{f}{q_v} = left

( frac{pi D^2 cdot m cdot d}{4 cdot Sr} right)^{-1} $$$ K $ It is only related to the geometric dimensions and Sr of the vortex generator and pipeline, and is not affected by fluid properties (density, pressure, temperature, etc.) within a stable Reynolds number range. Correction of gas flow rate When measuring gas flow rate, it is necessary to convert the working condition volume flow rate $q_V $to the standard state volume flow rate $q_ {Vn} $, with the formula: $$q_ {Vn}=q_V cdot frac {P} {P_n} cdot frac {Tn} {T} cdot frac {Z} {Z_n} $, where $P_n, Tn $are the absolute pressure and thermodynamic temperature under standard state; $Z_n, Z $is the gas compression coefficient under standard and operating conditions. The pulse frequency signal output by the vortex flowmeter only reflects the volumetric flow rate and is not affected by changes in fluid properties. However, if mass flow rate needs to be measured, fluid density needs to be monitored simultaneously, and changes in physical properties will directly affect the measurement results. The sensor and signal output gas vortex flowmeter use piezoelectric stress sensors to detect the pressure pulsation generated by vortices and convert it into electrical signals. The sensor has high reliability and operates within a temperature range of -20 ℃ to+250 ℃. The output signals include analog standard signals (such as 4-20mA) and digital pulse signals, which are easy to integrate with digital systems such as computers. Core advantage: Small pressure loss: Optimization of vortex generator design to reduce fluid resistance. Large range: suitable for a wide range of scenarios with low to high flow rates. High precision: Within a stable Reynolds number range, the instrument coeffi

Knowledge of Vortex Flow Meter | Working Principle of Vortex Flow Meter

1. Working principle of gas vortex flowmeter

『SILVER Official Website SERVICE』