22 February 2002

B5-06 Study on a Displacer Type Stirling Refrigerator as a Household machine

Environmental concerns are causing commonly used chlorofluorocarbon (CFC) refrigerants to be phased out of production. The less ozone-depleting HCFC’s will be regulate in the near future. The green house effecting HFC’s are also likely to be regulated and banned in the next 10-20 years. Accordingly, attention is drawn to the Stirling refrigerator, which is a perfect a freon free refrigerator. Moreover, The Stirling cycle has the highest theoretical cycle efficiency corresponding to the value of the Carnot cycle among the proposed thermodynamic cycles. The green house effect by carbon dioxide issue would make better recognizing the importance of efficient use of energy in terms of high energy conservation measures. Stirling refrigerators have been put to practical use in the fields of super conduction and space engineering. In general, it has been applied to low cooling capacity cryo-coolers, in order to obtain temperatures in the 10-15K range. However, Stirling refrigerators as household refrigerators with high efficiency and high cooling capacity have received limited study. A 100 W class Stirling refrigerator as a household refrigerator has been designed and constructed that operates. The operating characteristics of this refrigerator have been evaluated and are presented in this paper.
A prototype household Stirling cycle refrigerator employing helium as working fluid has been investigated whether a freon free machine be a viable alternative for a current household refrigerator. Attention is focused on the effects of a light, nylon mesh regenerator integrated in the displacer on performances of the prototype refrigerator. The nylon matrix has approximately 80 % of refrigeration capacity of copper matrix. The findings suggest that a refrigerator better optimized for the nylon matrix regenerator would be highly competitive to the HFC based refrigerators currently available as well as a base-line Stirling cycle refrigerator.