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『Calculation formula for gas pipeline flow rate』Related information(clamp on meter|electromagnetic meter|venturi meterrotameter|orifice meter|ultrasonic flow meter|mass flow meter|coriolis mass flow meter|coriolis flow meter|magnetic flow meter|magmeter flow meter|magflow flow meter|mag meter flow meter|electromagnetic flow meter|vortex flow meter|turbine flow meter|thermal mass flow meter|thermal flow meter|rotameter flow meter)
1. Calculation of Gas Pipe Diameter and Flow Rate
Given the "flow rate Q, pipe diameter D", calculate the flow rate: V=4Q/(3.1416 * D ^ 2). For low-pressure gas, the basic relationship between pressure P, pipe diameter d, flow rate Q, etc. is as follows: Rm=P/L=6.26 * 10 ^ 7 * λ * (Q ^ 2/d ^ 5) ρ * (T/To). In the formula: Rm - frictional loss per unit length of the gas pipeline; P - pressure difference at both ends of the pipeline; L - Pipe Chief; λ - resistance coefficient along the pipeline; Q - Calculated flow rate of gas pipeline; D - Inner diameter of gas pipeline; ρ - density of gas, kg/m^3； T - Gas temperature; To - reference temperature, To=273.16K。 Determination of resistance or excitation coefficient λ along the pipeline: laminar flow: Re<=2100, λ=64/Re (where Reynolds number Re=Vd/ν critical state: Re=2100~3500, λ=0.03+(Re-2100)/(65 * Re-10 ^ 5) Turbulence: sock Re>3500, steel pipe, λ=0.11+(K/d-68/Re) ^ 0.25
2. Please recommend a gas mass flow controller to measure nitrogen, hydrogen, and oxygen ..
3. Gas DN25 stainless steel pipeline with a flow rate of 5 kg pressure per hour
The gas flow rate range of DN25 stainless steel pipeline under 5 kg pressure is about 6.39-19.035m ³/h (natural gas conditions). 1. Estimation method and formula: Flow calculation is mainly based on the relationship between flow velocity and pipeline cross-sectional area formula: Q=A × v × 3600 (Q is the volume flow rate, A is the pipeline cross-sectional area, and v is the flow velocity). When estimating the inner diameter of DN25 stainless steel pipeline as 21.25mm, the cross-sectional area A is approximately 0.000355m ²
2. Example calculation
(1) When the flow rate is 5m/s: Q=0.000355m ² ×
(2) When the flow rate is 15m/s: Q=0.000355m ² × 15m/s × 3600=19.035m ³/h. 3. Key influencing factors
(1) Gas type: liquefied gas volume flow rate is lower than natural gas under the same pressure;
;(2) Pipeline length: Long pipelines will reduce actual flow due to pressure loss;
(3) Roughness of inner wall: If the roughness is too high, it will increase the frictional resistance;
(4) Temperature fluctuations: The volume of gas will expand or contract with temperature. In practical engineering applications, it is recommended to use specific working conditions, combined with the gas pressure loss formula or professional design specifications for verification. If necessary, gas engineers should use professional software (such as PipeFlow) for dynamic simulation.
4. What is the flow rate standard for natural gas pipelines
There is no fixed standard value for the flow rate of natural gas pipelines, and it needs to be calculated based on pipeline cracking parameters and gas demand. The following are specific calculation methods and typical scenario values
1. The general calculation formula adopts the internationally commonly used formula (unit: British system):$ q = 3550 \times [\frac{d^5}{(1 + \frac{3.6}{d} + 0.03 \times d)}]^{\frac{1}{2}} \times (\frac{h}{L \times SG})^{\frac{1}{2}}$ •q： Volume flow rate (CFH, cubic feet per hour) • d: Diameter of the collapsed pipeline (inches) • h: Pressure drop (inches of water column) • L: Pipeline length (feet) • Absolute SG: Gas specific gravity (0.60 for natural gas) 2 The calculation of urban gas pipeline flow is based on the maximum hourly gas consumption of the calculation month (unit: metric): $Q_ {h