Hitecsa EQPL-B 4360 Manual Del Operador página 52

I.5.2 Use of antifreeze solutions
The use of ethylene glycol is recommended if
you do not wish to drain the water from the
hydraulic system during the winter stoppage,
or if the unit has to supply chilled water at
temperatures lower than 5°C The addition of
glycol changes the physical properties of the
water and consequently the performance of
the unit. The proper percentage of glycol to
be added to the system can be obtained from
the most demanding functioning conditions
from those shown below.
Table "H"
Design air temperature in °C
% glycol in weight
Freezing temperature °C
fc G
fc Opw
fc QF
fc P
fc G Correction factor of the glycol water flow to the evaporator
fc Opw Correction factor of the pressure drops in the evaporator
fc QF Cooling capacity correction factor
fc P Correction factor for the total absorbed electrical current
I.5.3 Use of anti-freeze solutions with the BT accessory
The table provides the percentage of ethylene/propylene glycol to be used in units with the BT accessory, according to the temperature of the chilled
water produced. Use the UpToDate Software for unit performance.
Outlet water temperature
glycol evaporator
From -7,1°C a -8°C
From -6,1°C to -7°C
From -5,1°C to -6°C
From -4,1°C to -5°C
From -3,1°C to -4°C
From -2,1°C to -3°C
From -1,1°C to -2°C
From -0,1°C to -1°C
From 0,9°C a 0°C
From 1,9°C to 1°C
From 2,9°C a 2°C
From 3,9°C to 3°C
From 4,9°C to 4°C
Table "H" shows the multipliers which allow
the changes in performance of the units to be
determined in proportion to the required
percentage of ethylene glycol.
The multipliers refer to the following
conditions: condenser inlet air temperature
35°C; chilled water temperature 7°C;
temperature differential at evaporator 5°C.
For different functioning conditions, the same
coefficients can be used as their variations
are negligible.
2 0
10 15
-5 -7
1.025 1.039 1.054
1.085 1.128 1.191
0.975 0.967 0.963
0.993 0.991 0.990
Minimum % glycol
in weight
33
32
30
28
26
24
22
20
20
18
15
12
10
53
The resistance of the water side primary and
secondary heat exchanger (RA accessory),
the storage tank (RAS accessory) and the
electric pump unit (RAE-RAR accessory),
prevents undesired effects due to freezing
during the operating breaks in winter
(provided the unit remains powered).
Attention:
Besides the 20% glycol, check the pump
absorption limits (in versions P1/PR1-
P2/PR2, DP1/DPR1-DP2/DPR2, ASP1-
ASP2, ASDP1-ASDP2).
-3 -6 -10
20 25 30
-10 -13 -16
1.072 1.093
1.255 1.319
0.956 0.948
0.988 0.986
Minimum % glycol in weight
SECTION I :: USER
-15 -20
35 40
-20 -25
1.116 1.140
1.383 1.468
0.944 0.937
0.983 0.981
34
33
32
30
28
26
24
22
20
18
15
12
10