Analogue Input Natural Gas Flow Computer

The 515 GN02 application measures the volume, mass and gross heat content of natural gas by using analog volume flow, temperature and pressure inputs.

The Flowmeter input signal can be selected as either 0-5V, 1-5V or 4-20mA. Minimum and maximum points are programmed and non-linear correction points can be used to better reflect the flowmeters behaviour.

The AGA-8 Detail Characterization Method is used to obtain accurate values of density and compressibility factors for the flow calculations.

CALCULATIONS

The gas density and compressibility factor calculations are based on the AGA-8 equations. The calculations are valid for the region:

-130°C < t < 400°C P < 280MPa

-200°F < t < 760°F P < 40000psia

FORMULAS

Mflow = volumeflow•ρflow

Corrected flow = Mflow/ρ ref

Heat flow = Mflow•Hm

Where:

Mflow = mass flow

ρflow= density at flow conditions

ρ ref= density at reference conditions

Hm= mass gross heating value