23XL Product Information
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The 23XL screw chiller |
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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.
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 its 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.
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