Theoretical Approach And Development On A High Frequency Miniature Acoustic-Driven Thermoacoustic Refrigerator

The research of miniature high frequency thermoacoustic refrigerator faces many challenges such as sound field mismatch and viscosity losses caused by dimension decrease, especially lack of suitable high sound pressure resonating system became bottleneck of engineering application of the thermoacoustic refrigerator. In order to solve the problem author developed a high sound pressure resonating system and carried out study on fundamental theory, prototype manufacture and cooling tests as below:1. According to the linear thermoacoustic theory, we set up the model of high frequency thermoacoustic refrigerator; basic sound field distribution was confirmed; cone shape resonator was applied either decrease the viscosity losses or gather the acoustic dynamic energy; according to the optimizing design an adjustable resonator system and the whole test bed was accomplished;2. A suitable PZT acoustic driver was developed; combining with the optimized design of resonator shape, we established a high sound pressure resonating system; the 0.3 MPa peak to peak dynamic pressure was achieved under the mean pressure of 2.1 MPa with a well matched resonating system;3. The cooling tests under operating conditions decided by results of the driver tests were carried out. Compared to reported results nearly twice temperature difference and cold side temperature decrease was achieved in our tests,⊿T of 31oC and 15.2oC was achieved in our case;4. Heat exchanger design with theory of straight flow was made. Results show that using straight flow heat transfer correlations for analyses and design of this system could result in significant errors. Improvements in Heat exchanger design was introduced;...