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Thermodynamic comparison of two types of Stirling refrigerators.

Author(s) : WU Z. H., LUO E. C., DAI W., et al.

Summary

The pulse-tube type of a two-piston Stirling refrigerator can improve reliability by moving the expansion piston from the cold end to the ambient temperature end. More recently, the thermoacoustic-Stirling refrigerator further improves reliability by eliminating the expansion piston. The thermoacoustic-Stirling refrigerator uses a travelling-wave loop to achieve the Stirling cycle. Both refrigerators have a pulse tube. By means of thermodynamic analysis of the two refrigerators, this paper draws the following conclusions. Firstly, the pulse tube type of Stirling refrigerator can readily achieve any needed phase shifting by controlling the expansion piston, and it does not have to rely on the flowing resistance of the regenerator and the compliance and inertance effects of the different thermodynamic components that make contributions to phase shifting of the pressure and velocity waves. In contrast, the thermoacoustic-Stirling refrigerator is not able to perform active phase shifting, and its phase shifting mechanism is completely passive and somewhat dissipative because the flow resistance of the regenerator is a necessary part of the passive phase shifting. As a result, the pulse-tube type of two-piston Stirling refrigerator can achieve a little higher efficiency than the thermoacoustic-Stirling refrigerator. Secondly, the standing-wave acoustic field in the compression space of the thermoacoustic-Stirling refrigerator is predominant, resulting in smaller power flow for the same pressure wave amplitude and swept volume. In other words, the thermoacoustic Stirling refrigerator may give smaller cooling power with the same working conditions and component sizes. Actually, the calculations show that the two-piston Stirling refrigerator gives a much larger cooling capacity than the thermoacoustic-Stirling refrigerator.

Details

  • Original title: Thermodynamic comparison of two types of Stirling refrigerators.
  • Record ID : 2008-1069
  • Languages: English
  • Publication date: 2006/06/14
  • Source: Source: Proc. 14th int. Cryocooler Conf., Annapolis, MD
    249-255; fig.; tabl.; 7 ref.

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