Pipework, Primary Circuit - Viessmann VITOCAL 300-G Technical Manual

Design information
p = Permiss. terminal pressure in bar
e
= p – 0.1 · p = 0.9 · p
si si
p = Safety valve blow-off pressure = 3 bar
si
V + V
V =
Z V
N
· (P + 1)
e
P – P
e st
p = Nitrogen pre-charge pressure = 1.5 bar
st
Expansion vessel capacity for geothermal collector
V = Geothermal collector content incl. supply line + heat pump content = 130 l
A
V = V · β = 130 l × 0.01 = 1.3 l
Z A
× 0.005 = 130 l × 0.005 = 0.65 l → selected 3 l
V = V
V A
1.3 litres + 3.0 litres
V = · (2.7 bar + 1) = 13.25 litres
N
2.7 bar – 1.5 bar
Expansion vessel capacity for geothermal collector
V = Geothermal collector content incl. supply line + heat pump content = 220 l
A
V = V · β = 220 l × 0.01 = 2.2 l
Z A
× 0.005 = 220 l × 0.005 = 1.1 l → selected 3 l
V = V
V A
2.2 litres + 3.0 litres
V = · (2.5 bar + 1) = 15.17 litres
N
2.7 bar – 1.5 bar

Pipework, primary circuit

Pressure drop
The areas in the following tables with a grey background are subject
to laminar flow, thereafter turbulent flow.
For optimum heat extraction from the ground, we recommend sizing
the pipework in the turbulent area.
R value (resistance value):
■ R value = pressure drop/m line
■ The specified R values refer to Tyfocor heat transfer medium:
– Kinematic viscosity = 4.0 mm
– Density = 1050 kg/m
3
PE pipe 20 × 2.0 mm, PN 10
Flow rate R value for Tyfocor
l/h Pa/m
100
120
140
160
180
200
220
240
260
280
300
320
340
360
380
400
VITOCAL 300-G
(cont.)
si
2 /s
108.4
123.9
139.4
154.9
170.3
185.8
201.3
216.8
232.3
247.8
263.3
278.7
294.2
309.7
PE pipe 25 × 2.3 mm, PN 10
Flow rate R value for Tyfocor
l/h Pa/m
100
120
140
160
180
200
220
240
260
280
300
320
340
77.4
360
92.9
380
400
420
440
460
480
500
520
540
560
PE pipe 32 × 2.9 mm, PN 10
Flow rate R value for Tyfocor
l/h Pa/m
300
320
340
360
380
400
420
440
460
480
3
27.5
32.9
38.4
43.9
49.4
54.9
60.4
65.9
71.4
76.9
82.3
87.8
93.3
98.8
104.3
109.8
115.3
120.8
126.3
131.7
137.2
142.7
246.3
262.4
31.2
33.3
35.4
37.5
39.5
41.6
43.7
45.8
47.9
49.9
VIESMANN
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