24 June 2014
The on-going development of a compact centrifugal compressor as a first stage or pre-compressor for heat pumps is described. Positioned in the low pressure vapor portion
of the refrigerant loop, this compressor will, on cold days, boost refrigerant pressure, in a manner similar to the way the an automobile or aircraft engine supercharger pressurizes air.
Directly driven by a high-speed motor, the single stage centrifugal compressor runs on oilfree bearings. It is being configured to work in concert with a traditional heat pump compressor. The goal of this work is to enable air source heat pumps to efficiently extract
heat from even the coldest ambient air without backup heat and without changing refrigerant type or the basic design of the positive displacement style compressors widely used in
today’s heat pumps. Doing so will allow air source heat pumps to operate effectively in virtually all major markets. To date, a first article supercharger has been designed and built, and its performance mapped. Work to integrate it with a commercially available positive displacement (PD) heat pump compressor is underway.