Building, testing and modelling of a pulse tube cryogenic cooler

[摘要] ENGLISH ABSTRACT: Pulse tube cryogenic coolers (cryocoolers) are among the latest innovationsof cryogenic coolers. They fall in the same category as the reversed Stirlingcycle cryocoolers that have been used for decades to cool infrared detectorsin military and space applications. Pulse tube cryocoolers will replace most ofthe Stirling cryocoolers in future applications, because they have no movingparts at its cold point and therefore are subject to less vibrations, and hencehas a longer service life.Pulse tube coolers, like domestic refrigerators, are also driven by acompressor. The type of compressor used in this project is of thereciprocating type which is driven by a linear, resonant motor which is similarto a loudspeaker mechanism. This project is about the building, testing andmathematical modelling of a pulse tube cryogenic cooler.The pulse tube cryocooler and its reciprocator (reciprocating compressor) wasdesigned and manufactured. Numerous tests were conducted to evaluate thereciprocator. A complete mathematical model is presented for the reciprocatorwhich was compared with the data obtained from the tests. The pulse tubecryocooler was modelled with a one-dimensional, time dependant CFO(computational fluid dynamics) model by solving the discretized conservationequations which were derived in this project from first principles. Thediscussions and conclusions regarding these results are presented, togetherwith recommendations for future work.

[发布机构] Stellenbosch University