Shanghai Yichuan Instrument Orifice Flow MeterIt can be widely used in industries such as petroleum, chemical, natural gas, metallurgy, power, pharmaceuticals, etc. for continuous measurement of volume flow rate or mass flow rate of various liquids, gases, natural gas, and steam.

Simply put, the differential pressure value needs to be square root output to correspond to the flow rate

In practical applications, calculations are relatively complex and rarely done by oneself. This is usually calculated using software. Here is a practical example for you to see

1、 Overview of Traffic Compensation

The measurement principle of differential pressure flowmeter is based on the principle of mutual conversion of mechanical energy of fluid. The fluid flowing in a horizontal pipeline has dynamic pressure energy and static pressure energy (potential energy is equal). Under certain conditions, these two forms of energy can be converted into each other, but the total energy remains unchanged. Taking the volumetric flow formula as an example:

Q v = CεA/sqr(2ΔP/(1-β^4)/ρ1)

Among them: C outflow coefficient;

ε coefficient of expansion

The cross-sectional area of the orifice of the throttle component, M^2

The differential pressure output by the Δ P throttling device, Pa;

β diameter ratio

ρ 1 is the density of the measured fluid at position I-I, kg/m3;

Qv volumetric flow rate, m3/h

According to the compensation requirements, temperature and pressure compensation need to be added. According to the calculation sheet, the calculation idea is to use the process parameters at 50 degrees as the benchmark to calculate the flow rate at any temperature and pressure. Actually, the important thing is the conversion of density. The calculation formula is as follows:

Q = 0.004714187 *d^2*ε*@sqr（ΔP/ρ） Nm3/h 0C101.325kPa

That is to say, the volume flow rate required to be displayed on the screen at 0 degrees standard atmospheric pressure.

According to the density formula:

ρ= P*T50/（P50*T）* ρ50

Among them, ρ, P, and T represent values at any temperature and pressure

ρ 50, P50, T50 represent the process reference points at a gauge pressure of 0.04MPa at 50 degrees Celsius

By combining these two formulas, the programming can be completed in the program.