User Manual

30
Heating plant with low-pressure distribution, with k
VS
-valves (3-port)
Plant data Heating group 1 Heating group 2
Heating group power
100
90 kW 60 kW
Supply temperature producer θ
Producer
55 °C 55 °C
Temperatures Supply/Return θ
Supply
/ θ
Return
50/40 °C 35/28 °C
Temperature spread see below see below
Medium Water Water
Differential pressure Δp
MV
see below see below
Shutoff head pump H
0
(resp. Δp
V0
) 4.5 mWC (45 kPa) 4.5 mWC (45 kPa)
Positioning signal 3-position 3-position
Heating group 1 Heating group 2
1 Determine Volumetric ow
100
2 Determine Differential pressure Δp
v100
Hydronic circuit
Δp
MV
Differential pressure
across variable ow path
Mixing circuit
with pump
Mixing circuit with xed pre-mixing
with pump
Distribution setup low pressure
Δp
MV
typical range 2...5 kPa
typical value 3 kPa
Δp
V100
Δp
V100
≥ Δp
MV
(resp. P
V
≥ 0.5)
Desired differential pressure Δp
V100
≥ 3 kPa
decisive temperature difference
C
onstant 1.163:
with density
ρ = 1000 kg/m
3
, 3600 s/h and
specific heat capacity c = 4.187 kJ/kg · K
⩒
100
=
Q
100
1.163 · ∆T
θ
Producer
- θ
Return HG 1
= (55 – 40) °C = 15
K
90 kW
1.163 · 15 K
= 5.16 m
3
/h
⩒
100
=
θ
Producer
- θ
Return HG 2
= (55 – 28) °C = 27
K
60 kW
1.163 · 27 K
= 1.91 m
3
/h
⩒
100
=