关键词: 气波制冷, 静止式, 制冷效率, 附壁振荡, 双级振荡器

Abstract: In this study, it was found and confirmed one important reason for the low efficiency of static gas wave refrigerator by swing oscillation distributing gas injection. Because the periods and injection durations in every gas wave tubes are all not equal, the expansion ratio of the tubes located in both sides are decreased, very small load of the tubes located in intermediate region, and gas injection alternating fast and slow of each tubes deviated from the middle. These result in every gas wave tubes are not effective adequately. Refrigeration efficiency of each gas wave tubes located in different regions were calculated by computational fluid dynamics, and were compared with efficiency of the ideal injection pattern, so the restriction degree and growth potential of efficiency were exposed. Simulation showed that ideal 1/4 duty ratio pulse injection may improve relative value of efficiency about 45%, and that of 1/8 close to 70% comparing with that of the actual 1/2 duty ratio pattern. By the single tube model machine experiments, the refrigeration efficiency of same tube corresponding to different duty ratio gas injection modes were measured and compared. The results showed that the growth trend along with the decrease of the gas injection duty radio, and injection frequency corresponding to efficiency peak valley point, were consistent with the simulation results. For every gas wave tubes of the static gas wave refrigerator to efficient refrigeration, two kinds of novel and efficient wall oscillators that may distribute gas injection for four tubes with equal 1/4 duty ratio and equal cycle were recommended. Mechanisms and performances of the new type two-stage wall oscillator were also introduced succinctly.

Key words: gas wave refrigeration, static type, refrigeration efficiency, wall-attachment oscillation, two-stage oscillator