Contrec 515 series with GN12 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 flowmeter’s behaviour.
The SGERG calculation (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:
-8.0°C < t < 62.0°C P < 12MPa
17°F < t < 143.0°F P < 1740psia
FORMULAS
Mflow = volume flow• 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
