【作者】 胡鹏；

【导师】 李青；

【作者基本信息】 中国科学院研究生院（理化技术研究所） ， 制冷及低温工程， 2007， 博士

【摘要】 微型化高频热声制冷机的研究,由于频率升高、尺寸减小而引发了粘性损耗增大、声场不匹配等众多问题。尤其是缺乏合适的大压力幅值的振荡系统导致无法实现微型化高频热声制冷机的工程化应用。针对这一问题,本文从研制能产生高声压振幅的谐振系统出发,进行了以下热声制冷机微型化的应用理论基础、样机研制以及实验研究工作:1)以线性热声理论为基础,建立了微型化热声制冷机的模型;确定了系统内基本的声场分布;在谐振系统中引入了锥形管结构,在减小管内粘性耗散损失的同时,实现了管内局部声能密度的积聚;同时完成了多工况调节机构的设计,并在此基础上进行了各个热声元件的优化设计并建立了一整套微型热声制冷机试验台;2)研制了一种适合于微型热声制冷机的PZT声驱动器,结合谐振管的管型优化设计,可以形成高声压振幅的谐振系统;声驱动器与谐振管达到较好的声匹配,在均压2.1MPa的空管试验中可以获得最高0.3MPa的声压峰峰值;3)根据声驱动器试验确定的运行工况在改进后的试验样机上进行了制冷性能试验,结果表明,冷热端温差和冷端温降均超过了目前报道的同频率范围的微型制冷机近一倍。分别达到31oC和15.2oC;4)运用稳态流动理论估算换热器了的换热量,但是试验结果表明稳态的对流换热理论已经很不适用;预测了改进当前换热器设计的结果。更多还原

【Abstract】 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;更多还原