Endress+Hauser Proline Prowirl R 200 - Page 134

Commissioning Proline Prowirl R 200 HART
134 Endress+Hauser
Steam is calculated based on the following factors:
• Fully compensated calculation of density using the "pressure" and "temperature"
measured variables
• Calculation based on overheated steam until saturation point is reached
Configuration of diagnostic behavior of the diagnostic message S871 Near steam
saturation limitAssign behavior of diagnostic no. 871 parameter set to Off option
(factory setting) as standard →  153
Optional configuration of diagnostic behavior to the Alarm option or Warning option
→  152 option.
At 2 K above saturation, activation of the diagnostic message S871 Near steam
saturation limit.
• The smaller of the following two pressure values is always used to calculate the density:
– Pressure measured directly at meter body or pressure read in via current input/HART
– Saturated steam pressure, which is derived from the saturated steam line (IAPWS-
IF97/ASME)
• Depending on setting in the Steam calculation mode parameter (→  81)
– If Saturated steam (T-compensated) option is selected, the measuring device only
calculates on the saturated steam curve using temperature compensation.
– If Automatic (p-/T-compensated) option is selected, the device calculates using full
compensation either along the saturation line or in the superheated region, depending
on the steam state.
For detailed information on how to perform external compensation, see →  110.
Calculated value
The unit calculates the mass flow, heat flow, energy flow, density and specific enthalpy
from the measured volume flow and the measured temperature and/or the pressure based
on international standard IAPWS-IF97/ASME.
Formulae for calculation:
• Mass flow:  =  ⋅ ρ (T, p)
• Heat flow: =  ⋅ ρ (T, p) ⋅ h
D
(T, p)
 = Mass flow
= Heat flow
 = Volume flow (measured)
h
D
= Specific enthalpy
T = Process temperature (measured)
p = Process pressure
ρ = Density
2)
Pre-programmed gases
The following gases are pre-programmed in the flow computer:
Hydrogen
1)
Helium 4 Neon Argon
Krypton Xenon Nitrogen Oxygen
Chlorine Ammonia Carbon monoxide
1)
Carbon dioxide
Sulfur dioxide Hydrogen sulfide
1)
Hydrogen chloride Methane
1)
2) From steam data as per IAPWS-IF97 (ASME), for the measured temperature and the specified pressure