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Determining the required internal diameter
A
ΔT= 15K
ΔT= 20K
ΔT= 30K
ΔT= 5K
ΔT= 10K
C
B
D
2.5
2.5
Mixer control characteristics
2.0
0.1
0.2
0.5
1.0
1.5
5.0
Flow rate in m³/h
10
20 30 40
5
3
1
0.1
0.2
0.5
1.0
1.5
2.0
5.0
Heating circuit output
in kW
A
Divicon with three-way mixer
The identified operating ranges
B
to
D
provide optimum control
characteristics with the Divicon mixer:
B
Divicon with three-way mixer (R ¾)
Application range: 0 to 1.0 m
3
/h
C
Divicon with three-way mixer (R 1)
Application range: 0 to 1.5 m
3
/h
D
Divicon with three-way mixer (R 1¼)
Application range: 0 to 2.5 m
3
/h
Example:
Heating circuit for radiators with an output of
²
= 11.6 kW
Heating system temperature 75/60 °C (ΔT = 15 K)
c Specific heat capacity
µ
Mass flow rate
²
Output
´
Flow rate
²
=
µ
·
c · ΔT
c = 1.163
Wh
kg · K
µ
²
c · ΔT
=
kg
h
´
=
11600 W · kg · K
1.163 Wh · (75-60) K
= 665
m³
h
0.665
´
(1 kg ≈ 1 dm³)
Select the smallest possible mixer within the application range with
value
´
.
Result of this example: Divicon with three-way mixer (R ¾)
Circulation pump curves and pressure drop on the heating water side
The residual pump head results from the difference between the selec-
ted pump curve and the pressure drop curve of the respective heating
circuit distributor or further components (pipe assembly, distributor
etc.).
The following pump diagrams show the pressure drop curves of the
different Dicivon heating circuit distributors.
Maximum flow rate
for Divicon:
■ with R ¾ = 1.0 m
3
/h
■ with R 1 = 1.5 m
3
/h
■ with R 1¼ = 2.5 m
3
/h
Example:
Flow rate
´
= 0.665 m
3
/h
Selected:
Divicon with mixer R ¾ and circulation pump Wilo VIRS 25/4-3, pump
curve 2, pump rate 0.7 m
3
/h
Head of the relevant pump
curve:
28 kPa
Divicon pressure drop:
3.5 kPa
Residual head:
28 kPa – 3.5 kPa = 24.5 kPa.
Note
For further components (pipe assembly, distributor, etc.) determine the
pressure drop and deduct it from the residual head.
Installation accessories
(cont.)
38
VIESMANN
VITOGAS
4
5822 428 GB