Product Description; Introduction; General Specifications; Compressors - comatec AQWL Installations- Und Wartungshandbuch

7.1 Introduction

AQW units are water chillers /air-water heat pumps provided with
hermetic scroll compressors with two refrigeration circuits.
These units are fit for cooling and heating intermediate fluids (glycoled
water), for air-conditioning applications in industrial processes.
VERsIon (std/hsE) (1)
Base Low Noise version (BLN) (2)
Low Noise version (LN)
Extra Low Noise version (ELN)
High Temperature version (HT)
(1) High efficiency units (HSE) with brushless fans (2) A high pressure fan (HPF) version is available
For each AQW version, the corresponding condensing unit version (AQWC) is available.
Available options:
optIons
AQWL/D
AQWH/D
AQWR

7.2 General specifications

AQW units are supplied complete and provided with all connecting
pipes for the refrigerant and internal wiring.
The refrigeration circuit of each unit undergoes a pressure test, is
drained, vacuumised, dehydrated and filled with refrigerant, and
includes the necessary oil. Once assembled, each unit is subjected
to a complete final testing and the correct operation of all refrigeration
circuits is checked.
The base and the frame of each unit are made of very thick
galvanised sheet, and are secured by screw and stainless bolts. All
panels are secured by screw and tropicalised steel bolts, they can be
disassembled for easy access to internal components.
All galvanised steel parts are painted with white polyester resin
(RAL 9001), to ensure the resistance of the unit to corrosion and
weather agents over time.

7.3 Compressors

These units are provided with hermetic scroll compressors, with
built-in motor protection.
Compressors are mounted on shock absorbers to reduce vibrations.
Motors are of direct start-up type, cooled by the sucked refrigerant
gas.
Thermistors protect the windings from any overtemperatures and the
electronic control checks that the delivery temperature is within the
permissible range.
The capacity control, as well as the control of the delivered cooling
capacity, are always ensured by the electronic control.

7.4 Refrigeration circuits

Each unit has two complete refrigeration circuits, including: a service
valve to fill the unit with refrigerant, shut-off valves, thermostatic

7 - Product Description

dEscRIptIon
The heat recovery is carried out by a desuperheater mounted on the compressor's discharge line.
Total heat recovery is carried out by a heat exchanger mounted on the compressor's discharge line in parallel with
the condensing circuit. Heat recovery function is activated by mean of a 4-ways valve.
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These units can be installed outdoor on the roof of a building or at
ground level.
This series includes the following versions:
dEscRIptIon
Air condensing chillers/heat pumps, using R410A refrigerant.
expansion valve, dehydrating filter, sight glass with humidity indicator,
a differential pressure switch for the water.
The outdoor AQWC units, deriving from the AQWL versions, are
marked by the absence of the evaporator, and are equipped with
shutoff cocks on the suction line and on the liquid line, so as to allow
the connection of remote evaporators.
Furthermore, each circuit is equipped with safety devices in
accordance with PED 97/23/EC: HP and LP pressure switches,
safety valves providing protection in case of fire or malfunction of
compressors.

7.5 Water heat exchanger

The evaporators are of stainless steel plate type.
Their thermal insulation is ensured by a thick flexible closed-cell
heat-insulating jacket. Furthermore, the frost protection is ensured
by electric heaters.
These exchangers can work at pressures up to 10 bar on the
hydraulic side and 45 bar on the refrigerant side.
The hydraulic connections to the evaporator are of 3" Victaulic type.

7.6 Air heat exchanger

Coils are made of copper pipes in staggered rows, mechanically
expanded inside an aluminium finned pack.

7.7 Fans

Fans are of directly coupling propeller type, provided with aluminium
blade with wing profile.
Each fan is provided with galvanised steel accidentprevention guard.
Finally, motors are completely closed, protection class IP54,
protection thermostat immersed in windings.