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1. Calculation of Orifice Flow Meter
The core calculation formula of an orifice flow meter is qv=C × ε× A0 × √ (2 Δ p/ρ), and the calculation result directly reflects the flow rate.
1. Basic Parameter Analysis 1 Outflow coefficient C: It is related to the geometry of the orifice plate and the pressure measurement method, and needs to be obtained through experiments or by referring to standard charts. two The coefficient of expansion ε: for liquids, it is set to 1, while for gases, it needs to be corrected through charts based on pressure difference and temperature. three Opening area A0: calculated as A0=π d ²/4, where d is the measured inner diameter of the orifice plate. four Differential pressure Δ p: directly measured by a pressure sensor or U-tube, in Pa. 5. Density ρ: The density of the liquid is less affected by temperature, and the gas needs to be converted according to the working pressure and temperature.
2. Decomposition of Calculation Steps 1 Determine the fluid nature of the Mingshi field: distinguish between liquids or gases, and select the corresponding ε value. two Parameter measurement and acquisition: - Measure the diameter d of the orifice plate opening and calculate A0. - Record the reading Δ p of the pressure differential exciter. -Check the table or conduct experiments to determine C and ε. 3. Substitute into the formula for calculation: evaluate step by step according to qv=C ε A0 √ (2 Δ p/ρ).
III. Example Calculation of Water Flow Measurement in a Pump Pipeline: • Known Conditions: d=0.05m, Δ p=5000Pa, ρ=998kg/m ³ (20 ℃ water), C=0.62，ε=1。 • Calculation process: 1 A0=π× (0.05) ²/4 ≈ 0.00196m ². two Substitute into the formula: qv=0.62 × 1 × 0.00196 × √ (2 × 5000/998
2. Flow formula of orifice flowmeter
The core flow formulas of orifice flowmeter are volume flow formula and mass flow formula, which are classic fluid measurement formulas based on differential pressure method.
The basic differential pressure flow formula (universal derivation form) is derived based on Bernoulli equation and continuity equation, and is the universal basic formula for all differential pressure flow meters:$$ Q = C_d \times \varepsilon \times A_0 \times \sqrt{\frac{2\Delta P}{\rho}}$$ The meaning of each parameter in the revised manuscript is as follows: - $C_d $: flow coefficient, determined by the structure of the orifice plate, fluid flow state, and Reynolds number. The flow coefficient of a standard orifice plate can be obtained from industry standards. - $\ varepsilon $: expansion correction coefficient, used to compensate for the volumetric expansion effect of compressible fluids (gases, steam). For incompressible fluids, the value is 1- $A_0 $: the cross-sectional area of the orifice plate opening, $A_0=\ frac {pi d ^ 2} {4} $, $d $is the diameter of the orifice plate opening, - $\ Delta P $: the stati