Scroll expander for carbon dioxide cycle.


A design has been developed and refined for a scroll energy recovery expander for use in a CO2 air-conditioning circuit for an 18 000 Btu/hr military environmental control unit (ECU). The design is based on integration of the expander with an established-design two-stage rotary CO2 compressor. Key technical issues have been addressed through analysis, including bearing loads, friction, leakage, and material stresses and deflections. Testing in a static leakage fixture has been done to verify that refrigerant leakage through the expander, the largest anticipated loss mechanism, is less than initially projected. A proof-of-concept prototype with an internal geometry identical to the expander's design has been fabricated initially for testing in a shaft-output configuration. Initial testing of the prototype has been carried out at off-design conditions. Further testing to quantify the expander performance is ongoing.

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  • Original title: Scroll expander for carbon dioxide cycle.
  • Record ID : 2007-2045
  • Languages: English
  • Source: 2006 Purdue Conferences. 18th International Compressor Engineering Conference at Purdue & 11th International Refrigeration and Air-Conditioning Conference at Purdue [CD-ROM].
  • Publication date: 2006/07/17


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