33
6.5 -
System minimum water volume
Whichever the system, the water loop minimum capacity is given
by the formula:
Capacity = 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 and accurate
temperature control.
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
6.6 -
Maximum system water volume
Units with incorporated expansion tank (Opt. 293) have a maximum
water volume. The table below gives the maximum loop volume
for pure water or ethylene glycol with various system
concentrations, as well as the static pressures. If the maximum
volume is insufficient, compared to the minimum system water
loop volume, an additional expansion tank must be added to the
system.
30XB(E/P)ZE
Sizes 200 to 350
400
Static pressure
bar
1
2
2,5
1
2
2,5
Pure water
l
2400 1600 1200 3960 2640 1980
10% EG
l
1800 1200 900 2940 1960 1470
20% EG
l
1320 880 660 2100 1400 1050
30% EG
l
1080 720 540 1740 1160 870
40% EG
l
900 600 450 1500 1000 750
EG :
Ethylene Glycol
6.7 -
Evaporator water flow rate
30XBEZE &
30XBPZE
Minimum flow rate
(1)
(l/s)
Maximum flow rate
(2)
(l/s)
200
4,5
37,5
230
4,9
40,5
250
5,3
40,5
300
6,4
34,1
350
7,3
36,9
400
8,2
42,0
450
10,1
45,0
500
11,2
56,1
550
11,9
59,1
600
12,7
67,1
630
13,5
67,1
700
14,7
73,9
750
16,2
83,9
900
18,8
87,8
950
20,5
126,5
1050
22,0
92,9
1150
24,0
132,1
1200
25,1
107,4
(1) Minimum flow rate for optimal efficiency in variable flow configuration
(2) Maximum flow rate for a pressure drop of 100 kPa in the exchanger
6 - APPLICATION DATA
