Design, analysis, testing and development of a thermoacoustic system for refrigeration applications.

摘要

Thermoacoustic deals with the conversion of heat energy to sound energy or vice versa.;The numerical study has shown that the stack length and the position of the stack in the resonator have a significant impact on the overall performance of the thermoacoustic device. Air at standard temperature and pressure is employed as the working gas. The acoustic power source was a 15 W speaker operating at a frequency of 450 Hz. Based on a numerical study, the stack length was set equal to 3 cm with its center located at a distance of 5 cm from the driver-end of a 38.5 cm long resonator tube. The temperature difference between the two ends of the stack was set equal to 25 K.;A thermoacoustic refrigerator was developed based on the designed parameters. Preliminary experimental results have shown that a temperature difference of as high as 23 K was established across the stack. In order to exploit the thermoacoustic effect for heat pumping; heat exchangers were attached at both ends of stack. Water at ambient temperature was chosen as the working fluid for the heat exchangers to facilitate heat transfer to or from the stack. A pump was used to circulate water through both heat exchangers. Experimental results have shown that water temperature difference of 3 K for cold heat exchanger and 7.5 K for hot heat exchanger were established. The maximum coefficient of performance (COP) of this device was 1.5. Further research and development is needed in order to explore the full potential of the device in refrigeration applications. (Abstract shortened by UMI.).