Table of Contents
Advertisement
Ductable air-cooled scroll
chillers and heat pumps
Hydraulic connections
Installation water volume
Minimum installation volume
The electronic control for these units incorporates an auto-adaptive
control for the compressor operating time based on the time set for
anti-short-cycle.
This control reduces the number of times the compressor is started
up and permanently adjusts the system's thermal inertia, favouring
the reduction of the minimum volume of water in the installation. The
size of the buffer tank can also be decreased since the unit will be
stopped for less time.
30PA/PH/
Minimum
PAC/PHC
volume (I)
90STD
101
100STD
120
120STD
143
160STD
187
180STD
204
90HEE
107
100HEE
132
120HEE
152
160HEE
189
180HEE
210
The calculation of the minimum water volume has been done for nominal
EUROVENT conditions, only in cooling mode. This value is applicable
for the majority of refrigeration applications (group with fan-coil units).
Note: The buffer tank is indispensable in installations that operate with a
reduced volume of water (group with an air handling unit) or for industrial
processes. For applications with a heat pump, it is recommended that
the buffer tank be used in order to maintain a stable temperature during
the defrosting cycles.
Maximum installation volume
The water capacity for the installation obtained from this equation
corresponds to the maximum that
the installation allows based on the
expansion vessel assembled.
Where:
V
Installation volume (l)
inst
V
Expansion vessel volume (l)
inst
V
Initial volume of 1kg of water (at water temperature with the machine stopped)
1
V
Final volume of 1kg of water (at water temp. with the machine at normal speed)
2
P
Final network pressure (safety valve pressure in bars + 1)
f
P
Initial network pressure (absolute fi lling pressure of the installation in bars)
i
Note: If the hydraulic circuit has a buffer tank, its volume must be taken
into account for this calculation.
• Volume occupied by 1kg of water at different temperatures:
Temperature (ºC)
Volume (l)
0
1,00013
4
1,00000
10
1,00027
20
1,00177
30
1,00435
40
1,00782
16
Minimum
Maximum
fl ow (m
/h)
fl ow (m
/h)
3
3
2,2
6,2
2,7
7,4
3,1
8,8
4,1
11,3
4,3
12,7
2,1
6,7
2,9
8,1
3,3
9,5
3,7
11,7
4,0
12,8
V
⋅
(
P
−
P
)
V
vessel
f
i
=
INST
(
V
−
V
)
⋅
P
2
1
f
Temperature (ºC)
Volume (l)
50
1,0121
60
1,0171
70
1,0227
80
1,0290
90
1,0359
100
1,0434
Evaporator operating limits
The curves represent the minimum and maximum admissible
temperature increases based on the outlet (discharge) temperature,
for both pure water and glycol water.
For temperature changes that are not listed between the curves, please
consult.
The minimum outlet temperature for the unit will be +5ºC with pure
water and -7ºC with glycol water.
10
9
8
7
6
5
4
3
2
1
-7 -6
-4
-2
0
2
• Example
For an outlet water temperature of +5ºC:
Minimum temp.:
2,6ºC T. condition
Maximum temp.:
6,0ºC T. condition
Anti-freeze protection with glycol water
If a pure product is used for dilution in order to protect the hydraulic
circuit, the following instructions must be followed:
- Do not introduce any of the pure anti-freezing product separately
and then the water in the installation.
- Always prepare the water mixture + anti-freeze + corrosion inhibitor
at the correct dosage prior to introducing it into the installation.
Procedure:
- At minimum, a complete rinsing of the hydraulic installation must be
performed.
- After the fi nal rinsing, the installation must be completely drained.
- Introduce the water/anti-freeze/inhibitor mixture and increase the
pressure with a hydraulic pump.
We recommend using a fi lling device with a non-return valve for
compliance with the domestic anti-contamination standards. The
device must never in any case be connected to the city network if
the additives used in the hydraulic circuit are not approved by the
Ministry of Sanitation in the country of installation.
- Completely purge the installation.
- Circulate the mixture throughout the entire installation for a minimum
of 2 hours prior to starting up the unit.
- Check the fi nal dosage obtained with a densimeter or refractometer.
4
6
8
10
12
14
16
Water outlet temperature °C
7,6ºC / 5ºC
11ºC / 5ºC
18
Advertisement
Table of Contents
