A compressor ported shroud takes compressed air from the shroud of the compressor before it is completely compressed and delivers it to foil bearings. The compressed air has a lower pressure and temperature than compressed outlet air. The lower temperature of the air means that less air needs to be bled off from the compressor to cool the foil bearings. This increases the overall system efficiency due to the reduced mass flow requirements of the lower temperature air. By taking the air at a lower pressure, less work is lost compressing the bearing cooling air.
This invention was made with the support of the United States Government under Contract DE-FC04-02-AL67624 awarded by the Department of Energy under its PEM Fuel Cell Turbo-Compressor Program. The Government may have certain rights to this invention.