Frequency Input Natural Gas Flow Computer

The 515 GN01 application measures the volume, mass and gross heat content of a natural gas. The instrument uses a frequency volume flow input and analog temperature and pressure sensor inputs.

The instrument is compatible with a wide range of flowmeter frequency outputs. Millivolt signals, reed switches, Namur proximity switches or pulse trains can be selected via its smart front-panel programming.

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