High Speed Compressor Study
Abstract
The project examined several means of increasing the operating frequency of cryocoolers, with the goal of increasing the power per unit mass (or volume) of cryocooler compressors. A small increase in spring stiffness can be obtained by improving the design, materials and manufacturing techniques of the mechanical springs (flexures), but the consequent increase in operating frequency is small. The use of an auxiliary gas spring to increase frequency is studied in detail, particularly with respect to the compression losses and clearance seal losses. A gas spring can be used to give a very large increase in compressor operating frequency, but at these high frequencies these losses tend to become large, with a consequent reduction in efficiency. Use of a smaller gas spring, with lower losses, but a reduced increase in frequency, will provide a better design for most applications. A design method is described for the embodiment of a gas spring, and a worked example is given, showing how the power output of a particular compressor can be doubled, with a 40% increase in compressor size, and a much smaller increase in mass.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 21, 2011
- Accession Number
- ADA562695
Entities
People
- Charles R. Stone
- Mike Dadd
- Paul Bailey
Organizations
- University of Oxford