summary

The Weiliba flowmeter is an advanced instrument designed and manufactured specifically for measuring large caliber gas, flue gas, and power plant airflow based on the international standard I S0396 "Measurement of Fluid Flow in Closed Pipelines - Velocity Area Method". This flowmeter consists of a differential pressure sensing probe and a calculation display unit. This system has outstanding performance such as wide measurement range, low pressure loss (only 3% of the maximum differential pressure, efficient and energy-saving), non-stop gas maintenance, low fouling, and online cleaning. It is suitable for flow measurement of dirty, low-pressure, low flow rate large-diameter gas and air media.

measuring principle

The Velbar probe is the sensing part of the Velbar flowmeter, which converts the fluid flow velocity at a certain point in the pipeline into a corresponding differential pressure signal. It adopts a new generation of patented design structure, with a unique probe form that has the performance of measuring pressure loss and preventing dirt accumulation; The new threaded rod device can accurately adjust the insertion position of the measuring tube to ensure measurement accuracy; The sealed chamber and ball valve device allow for uninterrupted installation and maintenance of the measuring tube. The Weiliba flowmeter works based on the principle of dynamic pressure to static pressure conversion. The measuring hole on the upstream side of the probe measures the total pressure of the fluid, and the measuring hole on the downstream side of the probe measures the static pressure of the fluid. According to the Bernoulli equation, the relationship between flow velocity and differential pressure at the measuring head can be obtained as follows:

V: Flow velocity at the measuring head, m/s
△ P: Differential pressure measured by the Velbar flowmeter, Pa
ρ: The density of the measured medium, kg/m3
Kv: Velbar flowmeter coefficient
Calculate the flow rate based on the differential pressure of the Velbar flowmeter using the following formula:
Q=αβγAV×3600
Q: Fluid flow rate, m3/h
α: Velocity distribution coefficient
β: Blocking coefficient
Y: Section correction factor
A: The nominal cross-sectional area of the pipeline, m2
V: Flow velocity at the measuring head, m/s, and the performance of the power bar measurement system
The cross-sectional shape, surface roughness, and position of the low-pressure tapping hole of the average velocity flow probe are key factors determining the performance of the probe. low pressure
The stability and accuracy of the signal play a decisive role in the accuracy and performance of the averaging probe.
The reason why the Velbar probe can accurately detect the average velocity of the fluid is because it is arranged in a logarithmic linear manner in the high and low pressure zones of the Velbar probe
Multiple pairs of pressure tapping holes can accurately detect the average differential pressure generated by the average flow rate.