USA: Tests on a 40-ton spool compressor with low GWP refrigerants are said to have demonstrated improved efficiency and performance compared to current compressor designs.
The spool compressor developed by Torad Engineering, and tested at the company’s 13,000ft² facility in Cumming, Georgia, is said to have been proven suitable for medium pressure refrigerants such as R134a, as well as low and ultra-low GWP refrigerants like R513A and HFO1234yf.
The spool compressor resembles a rotary vane compressor, but is described as being smaller, lighter and cheaper to manufacture than current technology. It has four main components: rotor, main housing, vane, and bearing housing.
Torad claims its spool compressor has demonstrated improved efficiency and performance characteristics compared to scroll, screw and magnetic bearing centrifugal compressors.
The technology is targeted toward commercial chillers with compressor capacities under 100 tons, where the spool compressor has a cost advantage over legacy compressors. Unlike scroll and screw compressors employing complex geometries, Torad maintains that the components can be manufactured utilising lower cost capital equipment and easily scaled for larger sizes.
Financial support for the project came from five leading global manufacturers of commercial compressors and air conditioning chillers.
“Closed cycle testing of the prototype spool compressor proves the technology is an attractive alternative to legacy compressors utilising medium pressure refrigerants,” said Joe Orosz, Torad’s chief operating officer. “The spool compressor’s excellent performance at both full-load and part-load chiller conditions combined with its low manufacturing cost provides a viable path to affordable, high efficiency chillers.”
“Worldwide regulatory groups have made it pretty clear that ultra-low GWP refrigerants will be mandated in the future, the only real question is how soon,” said Greg Kemp, Torad’s founder and chief executive officer.
“The air conditioning industry is facing a genuine challenge regarding the delivery of ultra-low GWP air conditioning products that are more energy efficient while at the same time being affordable. Torad’s spool compressor has the potential to help meet these challenges.”
Torad says its development contracts preclude public release of full test data at this time but limited test results will be revealed at the International Compressor Engineering Conference at Purdue University in West Lafayette Indiana, USA, in July.