C150 – Upstream Density Calculation
Description
This calculation corrects the density to upstream conditions.
References
IP Petroleum Measurement Manuel: Part VII Section 2: Continuous Density Measurement
Implementation of ISO 5167:2003 at Gas Terminals for Sales Gas Metering Systems using Densitometers in the ‘bypass’ mode. Dti March 2007.
Kelton calculation reference C150
FLOCALC calculation reference F037
KIMS calculation reference K151
Options
Method
- Density exponent
This option calculates the upstream density using either the density or isentropic exponent as an input.
- Isenthalpic
This option calculates the upstream density using upstream and downstream temperatures and compressibility as inputs.
Density correction exponent
- Calculate from isentropic exponent
Check the box if you want to enter the isentropic exponent for use in the calculation.
Calculation
All calculations are performed in SI units unless otherwise stated.
Upstream density
When density exponent is the selcted method, the upstream density is calculated by:
Where
| ρ | = | Downstream density |
| p1 | = | Upstream pressure |
| Δp | = | Differential pressure |
| Ed | = | Density exponent |
| κ | = | Isentropic exponent |
When isenthalpic is the selected method, the upstream density is calculated by:
| Where | ||
|---|---|---|
| ρ | = | Downstream density (measured density at P2 T3 from the densitometer in bypass mode) |
| p1 | = | Upstream pressure |
| Δp | = | Differential pressure |
| T1 | = | Upstream temperature |
| T3 | = | Measured temperature at the downstream recovery point |
| Z1 | = | AGA 8 Compressibility at P1,T1 |
| Z3 | = | AGA 8 Compressibility at P2,T3 |