6.9 -
Variable flow evaporator
Variable evaporator flow can be used. The controlled flow rate
must be higher than the minimum flow given in the table of
permissible flow rates and must not vary by more than 10% per
minute.
If the flow rate changes more rapidly, the system should contain
a minimum of 6.5 litres of water per kW instead of 3.25 l/kW. It is
possible to use a dedicated terminal to connect the pump drive
(0/10V signal).
Please refer to SmartVu
TM
control manual.
6.10 - System minimum water volume
Whichever the system, the water loop minimum volume is given
by the formula: Volume = Cap (kW) x N litres
Application
N
Normal air conditioning
3,25
Process type cooling
6,5
Where Cap is the nominal system cooling capacity (kW) at the
nominal operating conditions of the installation.
This volume is necessary for stable operation.
It is often necessary to add a buffer water tank to the circuit in order
to achieve the required volume. The tank must itself be internally
baffled in order to ensure proper mixing of the liquid (water or
brine). Refer to the examples below.
Connection to a buffer tank
Bad
Bad
Good
Good
6.11 - Pressure drop curves
Units with two evaporator passes (standard)
Pressure drop, kPa
Water flow rate, l/s
10
20
30
40
50
60
70
80
90
100
110
120
0
10
20
30
40
50
60
70
80
90
1
2 3
Units with one evaporator pass (option 100C)
Pressure drop, kPa
Water flow rate, l/s
3
6
9
12
15
18
21
24
27
30
33
36
0
10 20 30 40 50 60 70 80 90 100 110 120
1
2
3
Units with two condenser passes (standard)
Pressure drop, kPa
Water flow rate, l/s
10
20
30
40
50
60
70
80
90
100
110
120
0
10 20 30 40 50 60 70 80 90 100 110 120
1
2
3
Units with one condenser pass (option 102C)
Pressure drop, kPa
Water flow rate, l/s
3
6
9
12
15
18
21
24
27
30
33
36
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
1
2
3
1
Sizes 580, 630
3
Sizes 1150, 1280, 1470, 1570, 1710
2
Sizes 810, 880
6 - APPLICATION DATA
19
