Effects of the optimized resonator dimensions on the performance of the standing-wave thermoacoustic refrigerator

Abstract

Thermoacoustic refrigerator is an alternative cooling system, which is environmentally safe due to the absence of any refrigerants. The resonator tube of the system is of great importance; its design and dimensions influence the design and performance of the entire refrigerator. The central component of the resonator is the stack. So this work describes the design of the stack and the resonator along with the influence of its dimensions on the performance of the standing-wave thermoacoustic refrigerator. The resonator consists of two tubes, one larger than the other, characterized by the diameter ratio of the small over the larger diameter. A Lagrange multiplier method is used as a technique to optimize the coefficient of performance (COP) of the system. The computational analyses show that the resonator small diameter tube dissipates minimum acoustic power at a diameter ratio of 0.46, which is about 17 percent (at least) less than the published values. Moreover, the results show that the resonator length increases gradually with the increase of the mean design temperature. The increase of the resonator length leads to increase of the total acoustic power dissipated by the resonator, which reduces the COP of the standing-wave thermoacoustic refrigerator.