Water-to-water chillers
Water-to-water chillers. The unit is supplied with anti-freeze oil and refrigerant and has been factory tested. On-site installation therefore just involves making connections to the mains power and water supplies.
Unit charged with R407C ecological refrigerant.
STANDARD UNIT COMPOSITION
Frame comprising supporting elements in polyester-painted thick
hot-galvanised sheet steel. The self-supporting frame containing the
main components is designed to ensure maximum ease of access
during servicing and maintenance operations. The various components
have been arranged to reduce the overall dimensions of the unit to a
minimum.
Screw compressors
Semi-hermetic screw-compressors with 2 five and six- lobe rotors. The
five-lobe rotor is directly splined onto the 2-pole motor (2,950 rpm)
without the use of overgears. Compression occurs five times every
motor turn and therefore the gas discharges continuously without the
typical throbbing of reciprocating compressors. Leading-edge
numerical control machines were used to make the rotors and
machine the bearing seats. The slide valve can limit the cooling
capacity of each compressor by 50% and 75%. In addition to the
standard no-load starting feature, the motors are fitted with electric
starting devices which limit the power absorbed during the compressor
starting phase. A check valve on the refrigerant delivery line prevents
the rotor from reversing after stopping. Special maintenance-free
bearings allow very long work cycles. Lubrication is forced, without the
use of an oil pump. The high efficiency built-in oil separator ensures
the constant presence of oil in the compressor. The rotors are
dynamically balanced to ensure the vibrations typical of reciprocating
compressors do not occur. The absence of vibrations and the absence
of delicate intake and delivery valves, in addition to very fine
manufacturing tolerances, sophisticated quality controls during the
production process and a limited number of moving parts, guarantee
quiet and highly reliable operation. Each compressor is fitted with
manual-reset motor thermal protection, delivery gas temperature
control, an oil level float, an oil level sight-glass and an electric
resistance for heating the oil when the compressor is stopped.
Water-refrigerant heat exchanger
Direct expansion heat exchanger type with asymmetric refrigerant
paths to maintain the correct refrigerant velocity inside the tubes
during both liquid and gaseous phases. The steel shell is insulated
with a closed-cell anti-condensation lining. The copper pipes are
internally grooved so as to improve the heat exchange. The pipes are
mechanically expanded onto the tube plate ends. An antifreeze electric
heater prevents the formation of ice inside the casing of the exchanger
when the unit is not operating but connected to the electrical supply.
Differential pressure switch for controlling the water flow is fitted
standard.
Refrigerant-water heat exchanger
Finned coil exchanger with steel shell and finned coil made from
copper tubes with external fins, mechanically expanded onto the tube
plate ends. The heads can be removed to inspect the tubes. Water
connections are fitted standard for water from towers; connectors for
water from wells can be supplied on request.
Refrigerant circuit
Each refrigerant circuit comprises the following components:
- compressor discharge check valve,
- liquid line shut-off valve,
- liquid line solenoid valve,
- dryer filter with replaceable cartridge,
- refrigerant line sight glass with humidity indicator,
- externally equalised thermostatic valve,
- high pressure safety valve,
- low pressure safety valve (if required by regulations).
- high and low pressure switches,
- high and low pressure gauges.
Electric power and control panel
Electric power and control panel, built to EN 60204-1/EC 204-1 standards, complete with:
- control circuit transformer,
- general door lock isolator,
- power circuit with bar distribution system,
- fuses and contactors for compressors,
- terminals for cumulative alarm block (BCA),
- remote ON/OFF terminals,
- spring-type control circuit terminal board,
- electronic controller.
Basic model
Unit without heat recovery.
Model with partial heat recovery (D)
Water cooled chiller with partial heat recovery. Compared with the
basic configuration, this version features an additional refrigerant/water
heat exchanger on the gas delivery line. This heat exchanger, fitted in
series before the traditional cooling circuit condenser, is large enough
to recover heat for the production of medium-to-high temperature
water for domestic hot water and the like. The heating capacity of the
heat recovery circuit is approximately equal to the power input of the
compressor.
Model with total heat recovery (R)
Water cooled chiller with total heat recovery. This version features an
oversized water/freon heat exchanger with a dual water circuit
comprising a dual shell and tube exchanger for heat condensation and
total recovery, all enclosed in a single steel shell with removable heads
and externally lagged in closed-cell neoprene. This exchanger is large
enough to recover condensation heat and produce hot water
(secondary or recovery circuit). Hot water can be produced in the
recovery circuit for domestic hot water and the like. The heating
capacity of this circuit is approximately equal to the cooling power plus
the power input of the compressor.
Accessories
Partial heat recovery (De-super heater)
Total heat recovery (Condenser)
Compressor suction valve
Compressor suction and discharge valve
Flanges on evaporator
Evaporator water flow switch (supplied separately)
Oversized electric heater on evaporator
Increased evaporator insulation.
Cu/Ni condensers
Pressure valve for water from wells (14/30ˇăC)
Spring isolators
Rubber isolators
Electronic expansion valves
Automatic circuit breaker for compressors
Numbered wires
Loc/O/Rem
Free voltage contacts for compr. operation signalling
Upgrade controller CVM300 to CVM3000
CVM-Interface (only for CVM300 and CVM3000)
CVM-Interface for 6 relay expansion board
CVM-Interface for 40 relay expansion board
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