The 23XL Hermetic Screw Liquid Chiller
Featuring the 23XL compressor
The 23XL from Carrier is the industry's first and
only centrifugal class screw chiller. With an ideal balance of
features - efficiency, reliability, quiet operation, and field
serviceability, the 23XL is the best value for medium sized commercial
applications such as schools, hospitals, manufacturing facilities,
and office buildings.
- Available in capacities from 150-360 Tons, 60Hz;
130-300 Tons, 50Hz.
- Exceptional full and part load efficiencies,
(from 0.59 kW/ton full load, 0.52 kW/ton IPLV) result in low operating
cost.
- Rugged, reliable and fully field-serviceable
compressor designed for a lifetime of trouble-free operation.
- ASME certified positive pressure design utilizing
HCFC-22 or HFC-134a refrigerant.
- Take apart design lowers installation cost.
- Industry best microprocessor controls provide
unsurpassed flexibility and functionality
- Quick ship program available for fast delivery.
The 23XL chiller utilizes a unique twin rotor
screw compressor. Because the 23XL was to compete in what was
traditionally a centrifugal chiller market, Carrier engineers
determined that the screw compressor could not sacrifice in any
critical area, including efficiency, reliability, sound, and serviceability.
The result is the industry's first and only centrifugal class
screw compressor; a robust design, world-class in every sense.
Unlike chillers which incorporate air compressors
adapted for air-conditioning duty, the 23XL utilizes a compressor
designed and optimized for air conditioning applications. As
a result, it suffers from none of the compromises associated with
misapplied technology.
High efficiency - Because one of the primary
factors to consider when purchasing a chiller is operating cost,
efficiency is of paramount importance. The 23XL compressor provides
outstanding efficiency
at full load and throughout it's part-load operating range. This
high efficiency, leveraged by advanced internally and externally
enhanced heat exchanger tubes, results in operating costs among
the lowest in the industry.
Carrier has achieved high efficiency compression
by combining an optimized design with ultra precise compressor
tolerances. By utilizing proprietary manufacturing techniques
available only recently, in conjunction with high precision bearings,
the 23XL screw rotors are positioned with clearances measured
in microns!
Reliability - It's not unusual for Carrier chillers
to last thirty years, or longer! With this tradition in mind,
Carrier designed the 23XL for the long haul, and achieved centrifugal
class, world class reliability.
With proper preventative maintenance, twenty, even thirty years
of service is definitely possible.
Of course, with the compressor being the heart
of the chiller, it was there that Carrier engineers concentrated
their efforts most heavily. Every component was scrutinized in
an exhaustive process of analysis, design, and testing. Particular
attention was paid to the critical moving elements; the rotors,
bearings, and slide valve. Let's look at each of these separately.
Rotors - The rotors are the defining element
of any screw compressor.
The rotors used in the 23XL were designed specifically
to compress refrigerant vapor for air-conditioning
applications. Their computer optimized
profiles are key in achieving high
efficiency throughout a broad
envelope of load and lift
conditions. This is a
hallmark of the
23XL design.
Bearings - The bearing system in the 23XL compressor
was designed to accommodate the high loading associated with air-cooled
chiller duty. But the 23XL chiller is water-cooled, and this duty
creates much lower loads. The bearing system therefore operates
very conservatively loaded. Add to this the fact that the bearings
are AFBMA class 5 rolling element type, the same type utilized
in jet engines and machine tool spindle applications. Clearly
this robustness significantly enhances long term reliability.
Capacity control slide valve - Here, Carrier
engineers applied their innovation in creating a unique design
that locates this critical device below the rotors rather than
above them. In this design, gravity accurately and repeatably
positions the valve in it's bore. The resulting tight tolerances
contribute to high efficiency. An extra benefit is that the bottom-mounted
design minimizes the wear potential resulting from rubbing between
the slide valve and rotors, a problem inherent in top-mounted
designs.
Sound - An inherently
quiet design makes the 23XL chiller ideal
for acoustically demanding applications, usually without the need
for costly field applied acoustic insulation.
Serviceability - The 23XL
compressor is unique in that it is the air-conditioning industry's
first and only fully field-serviceable
screw compressor.
This allows routine maintenance and inspections to occur in the
field, dramatically reducing expense and machine downtime. The
alternative is a compressor which must be sent back to the manufacturer's
factory for exchange; a costly and time consuming procedure.
An abundance of additional features further contributes
to the robust quality of the centrifugal class 23XL screw compressor.
- Hermetic design - Eliminates problems associated
with open-drive designs; shaft seal leakage, coupling maintenance,
noise, machine room heat rejection
- Motor cooling - Using the same design scheme
successfully utilized on thousands of Carrier 19D Series centrifugal
chillers
- O-ring seals - On the hermetic compressor, instead
of leak-prone gaskets.
- O-ring sealed fittings - Straight thread fittings
replace leaky, tapered pipe thread fittings
- Optional variable VI - Offers simple, automatically
controlled, compression ratio control for optimized dual duty
applications such as comfort cooling/thermal storage
- Testing - Each compressor undergoes a rigorous
run-in test to check proper operation and to verify vibration
levels and efficiencies meet specifications
With an exceptional combination of efficiency, reliability,
quiet operation, and serviceability, the 23XL compressor clearly
demonstrates true centrifugal class. For your water-cooled screw
chiller applications, let the 23XL compressor set the standard,
and choose the 23XL chiller to meet your needs.