Magnetic Bearings, Variable Speed Centrifugal Compression And Digital Controls Applied In A Small Tonnage Refrigerant Compressor Design

While great strides have been made in HVACR technologies in recent years, significant improvements in energy efficiency, reliability and product life have been elusive in mid-range applications. In this 50-500 TR range, the most promising potential for significant energy reduction lies in compressor integrated part load efficiency (IPLV) improvements. Although large chiller efficiencies have benefited from technology improvements like packaged variable speed drives, the far larger and less energy efficient mid-range market of rooftop packaged systems and smaller chillers has yet to benefit from these centrifugal compression related efficiencies and other available technologies. A nominal 60-90TR two-stage centrifugal oil-free R-134a refrigerant compressor utilizing integrated variable speed drive, magnetic bearings and an onboard digital control system affords major advantages for midmarket chiller and rooftop HVACR equipment.