Sensia QRATE Scanner 3300, Инструкция по установке, эксплуатации и обслуживанию

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Table 1.5—Fluid Property and Energy Flow Calculations
Standard Description N
at
ur
al
G
as
H
yd
roc
ar
bo
n
Li
qui
d
St
eam
ISO 6976
(2016)
ISO 6976 specifies methods for the calculation of the superior calorific value and the
inferior calorific value, density, relative density and Wobbe index of dry natural gas
and other combustible gaseous fuels, when the composition of the gas by mole frac-
tion is known.
A simplified version of the AGA 5 calculation,
ISO 6976 supports an
intermediate calculation and therefore is not a standard fluid property selection in the
QRATE Scanner 3300 Web Interface.
♦
IAPWS-IF97,
Saturated
Steam IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and
Steam. This calculation should be used when the steam is assumed to be at the sat-
uration temperature at a given flowing pressure. Only a pressure input is required.
Providing a steam quality measurement will yield an estimated liquid flowrate and
produce accumulations for vapor and liquid water.
♦
IAPWS-IF97,
All Regions IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and
Steam. This calculation should be used when measuring in regions off the saturation
line operating conditions and when the water is liquid or super-heated. A pressure
input and a temperature input are required. From the flowing condition inputs, the
operating region of the water is detected: liquid water (Region 1), dry steam (Region
2), critical range (Region 3), and saturated steam (Region 4). All regions except liquid
water are accumulated as vapor.
♦
17
QRATE Scanner 3300 integrated control flow computer Section 1