CHILLVENTA 2014 PREVIEW: German compressor manufacturer Bitzer promises a host of new recips, screws and scrolls on its 500m² stand.
One of these new products the compressor specialist will be showcasing is the further optimised CRII capacity control. The system is said to deliver virtually infinitely adjustable capacity control for the Ecoline reciprocating compressors with four, six and – now for the first time – two cylinders.
Depending on the operating conditions and refrigerant, a special control algorithm is said to allow compressors to be infinitely adjusted. With the CRII, Bitzer has achieved an exceptionally wide range of control between 10% and 100% for two-, four- and six-cylinder compressors. The increased switching frequency, however, ensures smaller fluctuations in controlled value, temperature as well as pressure and, in combination with the expanded range of control, optimizes system efficiency.
Bitzer is also always expanding its range of CO2 compressors. With the introduction of the 4PTC-6K model for lower displacements and the 4DTC-25K and 4CTC-30K models for higher displacements, the series for transcritical compressors now ranges from 4.3 to 25.6m³ of displacement per hour at 50Hz.
Screw compressor debut
For the first time, Bitzer is presenting a new, eye-catching open-drive screw compressor in the OS series to the public. The model is based on the tried-and-tested construction of the OS series and, for now, is designed for use with ammonia in medium and low temperature applications. Bitzer therefore offers the refrigeration and air conditioning industry a compressor solution tailored to meet the requirements of industrial applications. Further models for industrial applications are already in development.
CSVH3 compact screw compressors
The CSVH3 series is a new development in the field of regulated speed-regulated compact screw compressors. Bitzer has added two significantly more powerful larger models to its existing CSVH series. The CSVH37 compact screw compressor has a cooling capacity of 550kW (+5/50°C) with a displacement of up to 960m3/h. The larger CSVH38 possesses an impressive cooling capacity of 660kW (+5/50°C) with a displacement of up to 1,156 m3/h. Bitzer has developed a new housing size to achieve this level of performance.
The CSVW2 is also a compact screw compressor, specially designed for liquid chillers with a low condensing temperature. Its engineering is based on the tried-and-tested CSVH2 compact screw compressor and is said to combine proven strengths with new capabilities at low load conditions. In order to achieve a high coefficient of performance (COP) for this type of application, and thus a good ESEER, Bitzer has integrated a permanent magnet motor. The innovative drive technology is beneficial particularly in liquid chillers with a water cooled condenser. The internal volume ratio (Vi) of the compressor was also adjusted to allow the CSVW2 series to achieve much better efficiency in the lower speed and load range than the CSVH series. BITZER modified the frequency inverter accordingly.
The newly developed suction gas header plays a key role, as it specifically directs oil to one of the compressors and then, inside the compressor tandem or trio, distributes it evenly among the other compressors. The system even works when uneven compressors are combined and allows the frequency of a single compressor to be adjusted in the unit. The unit does not require active oil management with an oil separator or a lead compressor into which the oil can flow back. Even when one or two compressors are shut off, oil distribution is maintained.
Bitzer Advanced Header Technology is said to offer only one suction line for many compressor combinations without an individual combination of restrictor washers; reliable functioning at high and low suction gas volume flows; uneven capacity adjustment through different displacements in the unit; different compressor housing sizes (GSD6 and GSD8) can be combined in one unit; less warehousing, simpler installation and error prevention in the production of multi-compressor units
The lower oil carry over rate of the Orbit scroll compressors and the new suction gas header are said to promote longer operation with equalised oil levels in the compressors, even in demanding conditions, including the integration of reversible heat pumps and iced evaporators. The oil needs to be able to return to the suction line.
Chillventa, Nuremberg, October 14-16 2014
Hall 4, Stands 310, 408