Description

This calculates an observed volume flow rate of a gas to a mass, standard volume, normal volume or energy flow rate.

References

Kelton calculation reference C248

Options

Calculate for

• Observed volume
• Mass
• Standard volume
• Normal volume
• Energy

This option group is used to select which flow rate(s) are needed to be output.

Method

• Density
• Volume correction factor

This option allows the user to select whether to calculate a volumetric type flow rate using the equivalent gas density or by using a volume correction factor.

Calculate mass using

• Line density
• Standard density

Volume correction factor

• User entered
• Calculated

This option allows the user to enter a volume correction factor or have it calculated using PTZ inputs.

Calorific Value

• Volume based
• Mass based

This option allows the user to enter either a volume or mass based calorific value when calculating energy flow rate.

Standard density

• User entered
• Input as relative density

This option allows the user to select whether to enter standard density or enter a relative density, which will then be used to calculate standard density.

Calculation

Mass Flow Rate

The mass flow rate is calculated by:

If the density is calculated it is done by:

If the volume correction factor is calculated it is done by:

Where
P	=	Pressure at line conditions
Pb	=	Pressure at base conditions
T	=	Temperature at line conditions
Tb	=	Temperature at base conditions
Z	=	Compressibility at line conditions
Zb	=	Compressibility at base conditions
ρ	=	Density at line conditions
ρb	=	Density at base conditions
Qv	=	Observed volume flow rate

Standard Volume Flow Rate

The standard density is calculated by:

If the density method option is selected:

If volume correction factor option is selected:

Energy Flow Rate

The energy flow rate is calculated by:

If volumetric calorific value is applied:

If mass based calorific value is applied:

 

 

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