Compressors2013 highlights: technical advancements related to refrigeration compressors

During the successful IIR International Conference on Compressors and Coolants held in Casta Papiernicka in June 2013, several papers were dedicated to technological advancements related to refrigeration compressors 

 

 

 

J. Brasz presented(1) the main developments achieved regarding centrifugal compressors since its introduction in 1922, including oil-free direct-drive centrifugal compression technology introduced in 2003 by Turbocor (see photo). He highlighted the potential of two disruptive technologies currently being explored that could have a major impact:  shock-wave compressor and micro-sale compressor 

Supersonic shock wave compression, which is used for the engines on supersonic aircrafts, has been tested on air prototypes; if successful, this concept could result in higher compressor efficiencies and reduced compressor size. Recent introduction of smaller capacity high-speed direct-drive centrifugal compressors has moved the capacity of centrifugal compressors down to 200 kW 

Further miniaturization and/or the use of lower density refrigerants is required to reach the much slower capacities of the high volume residential air conditioning and refrigeration products 

 

. In his presentation(2), G. Boszormenyi stressed that the new generation of semi-hermetic reciprocating compressors features several advantages such as multi-refrigerant design (compatibility with multiple HFC refrigerants including low-GWP options), state of the art diagnostics and two methods of capacity control: capacity modulation using variable frequency – which allows the possibility to increase the capacity from 60% to 140% of nominal but implies high installation costs and electromagnetic emissions – and Digital modulation which represents a simple and cost-effective method to match the compressor’s output to system requirements and offers the possibility of keeping the suction pressure in the desired range 

 

. A. Hafner et al., from SINTEF, presented(3) test results regarding the development of a novel high-efficient single-stage 6-cylinder CO2 compressor driven by a permanent magnet with variable volume flow rates in the range of 18 to 90 m3/h. Overall efficiencies of 80% were measured 

 

(1) Past, present and future of turbo machinery in the HVACR industry, J. Brasz

(2) The new generation of semi-hermetic piston compressors, G. Boszormenyi

(3) High efficient 18-90 m3/h R744 compressor, A. Hafner et al