Steam Computer - DP Meter (AGA - 3)

The 515 SC05 application measures the volume, mass and energy content of steam by using single or stacked differential pressure flow inputs in conjunction with a temperature and/or pressure input.

A selection of various modes makes it suitable for many steam applications. The flow is calculated according to the AGA-3 differential pressure equations. The flow calculations incorporate the conditions at which the flowmeter was calibrated and accurately account for thermal expansion effects.

The instrument calculates the mass flow and energy according to the IAPWS Industrial Formulation (1997) for the thermodynamic properties of steam. The equations use pressure and temperature values to determine the specific volume and the specific enthalpy.

CALCULATIONS

The steam energy calculations are based on the IAPWS Industrial Formulation (1997).

Superheated steam regions are:

0°C < t < 800°C P < 100MPa
32°F < t < 1472°F P < 14500psia

800°C < t < 2000°C P < 10MPa
1472°F < t < 3632°F P < 1450psia

Saturated steam regions are:

0°C < t < 374°C (critical temperature)
32°F < t < 705°F

P < 22MPa (critical pressure)
P < 3190psia

Water region is:

0°C < t < t saturation at system pressure
32°C < t < t saturation at system pressure

Formulas

Volume flow = Mass flow x Specific volume

Energy flow = Mass flow x Specific enthalpy