C283 – ISO 5167/McCrometer Wet Gas V-Cone Flow Calculation (Steven)

Description

This calculates the flow rate of a wet gas through a v-cone meter.

References

ISO 5167: Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full

ISO TR9464: Guidelines for the use of ISO 5167

24509-54 Flow Calculations for the V-Cone and Wafer-Cone Flow meters – McCrometer

24517-16 V-Cone Flow Meter Technical Brief – McCrometer

Wet Gas Metering with V-Cone Meters – R Steven, RJW Peters, D Hodges, D Stewart

Kelton calculation reference C283

FLOCALC calculation reference F099

Options

Discharge coefficient

• User entered
• Variable with Reynold’s number

This option gives the user the choice of calculating discharge coefficient against Reynold’s number using linear interpolation or entering a key pad value.

Standard version

• 2000
• 2005

This option group allows selection of the year of McCrometer technical publications with regard to their v-cone meters.

Expansibility factor

• User entered
• Calculated

This option gives the choice for expansibility factor to be entered by the user or calculated.

Beta Ratio

• 0.55
• 0.75

This option is used so that the appropriate equations are used which are dependant on beta ratio.

Determine Lockhart-Martinelli

• Enter total mass flow rate
• Enter liquid mass flow rate
• Enter gas mass fraction

This option is used to select how the Lockhart-Matinelli parameter is to be calculated based on the data available to the user.

Calculation

Corrected Mass Flow Rate

The corrected mass flow rate is calculated by an iterative procedure using the flowing formulae:

 Where qm_unc = uncorrected gas mass flow rate Φ = wet gas correction factor

The calculations for uncorrected flow rate can be found in C272.

Wet Gas correction

The wet gas correction is calculated by:

 Where X = Lockhart-Martinelli parameter Frg = Gas Froude number

And Constants A, B and C are determined by:

 Where ρg = Gas density ρl = Liquid density

Lockhart Martinelli Parameter

The Lockhart-Martinelli parameter is calculated depending on the option selected from either:

or

 Where χ = Gas mass fraction ρg = Gas density ρl = Liquid density qm_gas = gas mass flow rate qm_liq = liquid mass flow rate

Froude number

The gas densiometric Froude number it calculated by:

 Where v = Superficial gas velocity D = Corrected pipe diameter g = Gravitational acceleration

Back