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 |