The first part of Dr. Peter Kittel’s “Introduction to Pulse Tube Thermodynamics” was featured in the Fall 2012 issue of Cold Facts, which will be available for download soon. The series will continue in the 2013 Buyer’s Guide and throughout the coming year. The nomenclature, appendices and references for the series are available on CSA’s Resources page.
Below is the Foreword to “Introduction to Pulse Tube Thermodynamics.”
“This review of pulse tube thermodynamics is based on a series of lectures given at the Zhejiang University, Hangzhou, China in 2011. It uses the first and second laws of thermodynamics to demonstrate the operation of ideal pulse tube cryocoolers and many of their loss mechanisms. The review investigates the underlying physical processes that occur within pulse tubes. It starts with an analysis of an idealized system and develops the system efficiency
and thermodynamic behavior in the cryocooler components. Then, the various assumptions of idealization are removed one-by-one to explore the effect the various loss mechanisms have on performance. The non-ideal behavior includes the effects of heat transfer, void volume, pressure drop, transitions between components, and real gas effects of 4He, 3He, and 3He-4He mixtures.
“While the approach uses particular properties of pulse tube cryocoolers, much of the material also applies to other regenerative cryocoolers such as the Stirling, Vuillemier and Ericsson cycles. In the small amplitude limit used here, these regenerative coolers only differ from the pulse tube cycle in the phase shift mechanism and associated loss mechanisms.
“Gifford-McMahon coolers rarely operate at small amplitudes and have particularly lossy compressors and expanders. The discussion here is only a rough guide to the operation of these coolers.”
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