Quantech QTC40160, Установка, эксплуатация и обслуживание

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Section 2 - Product description
Quantech
17
Form QTC4-NM2
Issue date: 05/12/2023
2
Semi-hermetic Quantech twin-screw
compressors
Compressors are direct drive, semi-hermetic and
rotary twin-screw type, and include the following fea-
tures:
• Muffler
• Temperature actuated off-cycle heater
• IP55 terminal board
• Precision machined cast iron housing
•
Reliable suction gas cooled, high efficiency, ac -
cessible hermetic compressor motor
• Full suction gas flow through mesh screen filter
• Inherent internal thermal overload protection
• External current overload on all three phases
Continuous function, microprocessor controlled,
variable speed drive (VSD) must provide valve-less,
smooth capacity control from 100% down to 10% of
chiller capacity.
In addition, elimination of the slide valve and associ-
ated unloading components results in a 50% reduction
in compressor moving parts.
Evaporator
The evaporator is a two-circuit, series counterflow
shell and tube, hybrid falling film type heat exchanger.
It contains a balance of flooded and falling film tech-
nology to optimize efficiency, minimize refrigerant
charge, and maintain reliable control. A specifically
designed distribution system provides uniform refrig-
erant flow for optimum performance.
Condenser
The QTC4 Style B introduces next-gen 4G microchan-
nel coils to the Quantech screw compressor chiller line.
This design allows for bigger flow channels, reducing
refrigerant pressure drop by three to four times and
improving condenser performance. The microchan-
nel maximizes condenser heat transfer, resulting in a
smaller footprint, and reduces refrigerant charge by as
much as 50%.
Each condenser coil is a single piece all aluminum
construction including headers, tubes and fins to avoid
galvanic corrosion due to dissimilar metals. Coils and
headers are brazed as one piece. Integral subcooling
is included. The design working pressure is 375 psig
(25.9 barg).
Multiple, standard low sound, high efficiency, variable
speed drive motor driven fans move air through the
coils. They are dynamically and statically balanced,
direct drive with corrosion-resistant glass fiber rein-
forced composite blades molded into low-noise, full
airfoil cross sections, providing vertical air discharge
from extended orifices for efficiency and low sound.
Fan motors are totally enclosed air-over (TEAO),
squirrel-cage type and current protected. The direct
drive motors feature double-sealed and permanently
lubricated ball bearings, cutting down on mainte-
nance cost over the life of the unit. The chiller is also
equipped with the option of variable speed electroni-
cally commutated (EC) motors to provide extra airflow
across coils with lower power consumption, resulting
in higher efficiencies.
Refrigerant circuit
An independent refrigerant circuit is provided for each
compressor. Each circuit uses copper refrigerant pipe
formed on computer controlled bending machines to
reduce the number of brazed joints resulting in a reli-
able and leak resistant system.
• Discharge lines are provided with a manual com-
pressor shutoff service valve. See Accessories and
options on page 19
, for service isolation valve.
• The external oil separators, with no moving parts
and designed for minimum oil carryover, are
mounted in the discharge line of the compressor.
• Liquid line components includes the following
components:
• High absorption removable core filter-drier
• Sight glasses with moisture indicators
• Manual shut-off valve with charging port
• Orifice and electronic expansion valve.
• A brazed plate heat exchanger is located in each
refrigerant circuit to increase the system efficiency.
Electrical
Quantech has years of experience designing variable-
speed drives specifically for chiller applications. The
result is an extremely reliable air-cooled chiller system
that offers industry leading efficiency at real world op-
erating conditions, valve-less compressor loading/un-
loading, excellent capacity control, high power factor
and soft start.