밀폐관형 스피커구동 열음향 냉동기의 주파수 및 온도변화 연구

Abstract

In general, the thermoacoustic refrigeration technique employs either the pulse-tube type refrigeration or the resonator type refrigeration. In the resonator type refrigeration technique, it can be classified into the heat-driven type and the speaker-driven type. The purpose of this study is to develope a resonator type thermoacoustic refrigerator driven by a loudspeaker.

In this study, a resonator type thermoacoustic refrigerator is designed and fabricated according to the method suggested by Hofler. The resonator type thermoacoustic refrigerator is composed of a resonator of 4 cm diameter, stack of plates, heat exchangers and cooling part. The fundamental operation frequency of this thermoacoustic refrigerator is 250Hz. Lengthes of the hot heat exchanger the stack of plates and the cold exchanger heat exchanger are 15 mm, 7 cm and 9 mm respectively. Heat exchnger are constructed by the wire cutting method. Stack of plates is of spiral type having a finite spaces of 0.7 mm and is made of Kapton. The total length of the resonator type thermocaoustic refrigerator can be different according to the kind of filling gas and the driving frequency.

Maximum temperature drop of the thermocaoustic refrigerator is observed to be 15。C when it is operated at 250Hz of driving frequency and 161.319dB of sound pressure level. Calculated efficiency(□) of this theramoacoustic refrigerator is 6.78%. It is concluded that the thermoacoustic refrigerator has optimum operation frequency according to the length of resonator and the stack.