VortexMaster FSV430, FSV450 SwirlMaster FSS430, FSS450
| CI/FSV/FSS/430/450-EN Rev. G 53
For the energy measurement, the media types "saturated
steam", "superheated steam" or "hot water“ can be selected.
The calculation is done according to IAPWS-IF97.
Calculation of the net energy for steam
water
steam
m
p
H
H
Q
Q
Calculation of the net energy for hot water / condensate
out
water
in
water
m
p
H
H
Q
Q
_
_
Formula elements used
Q
p
Net
energy
Q
m
Mass
flow
H
steam
Steam
enthalpy
H
water
Water
enthalpy
H
water in
Water enthalpy (feed flow)
H
water_out
Water enthalpy (return flow)
Prerequisites for the energy measurement:
— For energy measurement of steam, this must condense
completely.
— The process must form a closed system, energy losses
through leaks are not recorded.
Steam mass calculation
The following options are available for the steam mass
calculation:
— Density calculated from the temperature (saturated steam
only)
— Density calculated from the pressure (saturated steam
only)
— Density calculated from pressure and temperature
— Constant
density
If a pressure transmitter is connected, the steam state is
checked automatically. A distinction is made between wet
steam, saturated steam, and superheated steam. The correct
density is always calculated regardless of the selected media
type.
If a pressure transmitter is not connected and steam type
"Overheated Steam" is selected, a constant pressure must be
entered for the state to be detected and, if applicable, the
density to be calculated.
A value must always be stored for the steam density value
(constant) in the transmitter in order to define the measuring
range limits for Q
max
DN in mass flow units.
An approximation is sufficient here, the density diagrams
provide an indication for determining the steam density.
Density diagrams
The following diagrams show an extract from the density table
for saturated steam at different temperatures / pressures.
Fig. 48: Saturated steam density vs. temperature
ρ Steam density T Temperature
Fig. 49: Saturated steam density vs. pressure
ρ Steam density p Pressure
G11882
ρ [kg/m ]
³
T
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
100
115
130
145
160
175
190
205
220
235
250
265
280 [°C]
0
0.1
0.2
0.4
0.5
0.6
0.7
0.9
1.0
1.1
1.2
1.4
1.5
1.6
1.7
1.9
2.0
2.1
212
239
266
293
320
347
374
401
428
455
482
509
536 [°F]
ρ [lb/ft ]
³
G11883
ρ [kg/m³]
0
1
2
3
4
5
6
7
8
9
10
11
12
0
0.06
0.12
0.19
0.25
0.31
0.37
0.44
0.50
0.56
0.62
0.69
0.75
0
2
4
6
8
10
12
14
16
18
20
22
24
(0)
(29)
(58)
(87)
(116)
(145)
(174)
(203)
(232)
(261)
(290)
(319)
(348)
p [bar abs (psia)]
ρ [lb/ft³]
