Calculate flow rates with real gas behavior
Volumetric Flow (Actual)
-
m³/h at flow conditions
Mass Flow
-
kg/h
Standard Flow
-
Nm³/h at 0°C, 1.013 bar
-
Dimensionless
-
Dimensionless
-
kg/m³ at flow conditions
-
m/s in 6" pipe
| Condition | Volumetric Flow | Mass Flow |
|---|---|---|
| Actual Conditions | - | - |
| Standard (15°C, 1.013 bar) | - | - |
| Normal (0°C, 1.013 bar) | - | - |
The ideal gas law (PV=nRT) must be modified for real gases:
PV = ZnRT
where Z is the compressibility factor accounting for:
- Molecular interactions
- Finite molecular volume
- Non-ideal behavior at high pressure/low temperature
Gas volumes change significantly with conditions. Conversion between actual and standard flow:
Qstd = Qact × (Pact/Pstd) × (Tstd/Tact) × (Zstd/Zact)
where:
- Q = volumetric flow rate
- P = absolute pressure
- T = absolute temperature
- Z = compressibility factor
Mass flow (ṁ) is often preferred as it's independent of conditions:
ṁ = ρact × Qact = ρstd × Qstd
where ρ is gas density calculated as:
ρ = (P × MW)/(Z × R × T)
with MW = molecular weight, R = universal gas constant
