POWER Engineers

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POWER Engineers Tom McAuliffe Geothermal Steam
Flow Measurement
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Fundamentals

• References
• ASME MFC-3M 1989
• Miller Flow Measurement Engineering Handbook
• Bernouillis Equation

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Venturis
Note300 Flange Rating for Stainless

• Highly Accurate
• Low Energy Loss
• Oil filled diaphragm seals
• Multivariable flow transmitter

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Fundamentals Redux

• Amagats Law (S of the Volumes)

• Daltons Law (S of the Pressures)

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Density of the mixture
Miller eqn 2.9 2.100
rH2O is calculated at the water vapors partial
pressure
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Steam Properties, rf (XpH2O or pH2OTSH)
If you cant dazzle them with brilliance
Saturated Steam Conditions
Superheated Steam conditions
pH2O is the water vapors partial pressure
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NCG Compressibility Factors
Hint use MS Excels Goal Seek function to solve
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Z Compressibility Factors
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e, The Gas Expansion Factor a minor fly in the
ointment

• Problem density change through meter

k is the isentropic exponent t is the ratio of
throat to upstream pressure
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Expansion Factor e versus k

• Solution Cheat. Use the k for steam alone
• e is not sensitive to variations
  in k

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Only 0.45 change in e over a wide range of k
values
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The flow equation
As elegant as it gets
SI Units