Technibel PHRT 9 - Corrections to be Made When Using Anti-Freeze; Curves of Available Pressures

9
(Cooling mode)
IMPORT
ANT:
Use monopropylene glycol.
A minium rate of 15% to 20% is needed to avoid any risk of
corrosion.
8.1 - PRINCIPLE OF USING THE CURVES
•
Choose the percentage of glycol according to the minimum
temperature to protect the hydraulic circuit against frost and
determine the coefficients to be applied to the power, the water flow
rate and the pressure drop.
8.2 - EXAMPLE
•
Protection at an external temperature of -15°C, which gives 30%
glycol ("Freezing points" curve).
•
The "Reduction of cooling capacity" curve gives the coefficient to be
applied to the refrigerating capacity (0.94).
• The "Water flow" curve gives the coefficient to be applied to the water
flow rate (1.113).
• The "Pressure drop" curve gives the coefficient to be applied to the
pressure drop (1.19).
Curves valid for temperature control on the water intake.
8 - CORRECTIONS TO BE MADE WHEN USING ANTI-FREEZE
1.30
1.20
1.10
1.00
0.94
0 10 20 30 40
0
-5
-10
-15
-20
-25
1.19
1.113
% in weight of Monopropylene Glycol
Pressure drop
Water flow
Reduction of cooling capacity
Freezing points
Correction factorsOutdoor
temperature °C
9 - CURVES OF AVAILABLE PRESSURES (on unit's outlet)
0
0 0.5 1 1.5 2
10
20
30
40
50
60
70
80
100
90
PHRT 7
PHRT 9
W
ater flow rate (m
3
/h)
Available pressure (kPa)
Speed 1
Speed 2
Speed 3
0
0 0.5 1 1.5 2.52
10
20
30
40
50
60
70
80
130
120
110
100
90
PHRT 12
W
ater flow rate (m
3
/h)
A
vailable pressure (kPa)
Speed 1
Speed 2
Speed 3