Flow rate measurement method for spiral throttling component

A flow rate measurement method for a spiral throttling component, wherein a spiral flow channel is formed inside the spiral throttling component, and the spiral throttling component is further provided with a differential pressure sensor, and the differential pressure sensor is used to measure a pressure drop DP before and after a fluid flows through the spiral flow channel;

• comprising the following steps:
• step 1:
• introducing a calibration medium into the spiral throttling component, wherein an embedded controller samples an analog pressure signal from the differential pressure sensor at a defined sampling frequency and stores raw pressure data in a memory, and acquiring a plurality of calibration datasets, with each of the plurality of calibration datasets comprising flow rate Qv, pressure drop DP, and Reynolds number Re at a same moment;
• step 2:
• calculating, by the embedded controller, a flow coefficient k of the calibration medium flowing through the spiral throttling component according to the following Formula {circle around (1)};
• k
• =
• Q
• ⁢
• v
• d
• n
• L
• m
• *
• DP
• ρ
• ;
• Formula
• d is a diameter of the spiral flow channel;
• L is an equivalent length of the spiral flow channel;
• n and m are both exponents;
• DP is the pressure drop before and after the calibration medium flows through the spiral flow channel;
• ρ is a density of the calibration medium;
• adjusting values of the exponents n and m and determining a relationship of k=f(Re);
• step 3:
• calculating, by the embedded controller, a flow rate Q of a fluid to be measured flowing through the spiral throttling component according to the following Formula {circle around (2)};
• Q
• =
• K
• *
• d
• n
• L
• m
• *
• DP
• ‵
• ρ
• ‵
• ;
• Formula
• DP′ is a pressure drop before and after the fluid to be measured flows through the spiral flow channel;
• ρ′ is a density of the fluid to be measured;
• K is a flow coefficient of the fluid to be measured;
• {
• K
• =
• a
• 1
• *
• ln
• ⁢
• (
• Re
• )
• -
• b
• 1
• ,
• Re
• <
• x
• 1
• ;
• K
• =
• a
• 2
• *
• ln
• ⁢
• (
• Re
• )
• -
• b
• 2
• ,
• x
• 1
• ≤
• Re
• <
• x
• 2
• ;
• K
• =
• c
• ,
• Re
• ≥
• x
• 2
• ;
• a1 and b1 are fitting parameters for a low Reynolds number and are obtained by fitting the relationship of k=f(Re) in the step 2;
• a2 and b2 are fitting parameters for a medium Reynolds number and are obtained by fitting the relationship of k=f(Re) in the step 2;
• c is a fitting constant for a high Reynolds number and is obtained by fitting the relationship of k=f(Re) in the step 2;
• Re is a Reynolds number for the fluid to be measured;
• x1 is a piecewise value of the low Reynolds number and the medium Reynolds number;
• and
• x2 is a piecewise value of the medium Reynolds number and the high Reynolds number,
• wherein the embedded controller automatically outputs the computed flow rate Q to the display in real time;
• and
• step 4:
• actuating, by the embedded controller, a downstream flow-control valve to adjust the flow of the fluid based on the computed flow rate Q.