Experimental study and analysis of a thermoacoustically driven thermoacoustic refrigerator

Experimental investigations are performed on a half-wavelength standing wave type thermoacoustically driven thermoacoustic refrigerator also known as TADTAR. Present TADTAR device conceived to be a quarter wavelength standing wave type thermoacoustic engine (TAE) coupled to a quarter wavelength standing wave thermoacoustic refrigerator (TAR). A TAE generates acoustic work using heat, and this produced acoustic work is directly fed to TAR where a useful cooling effect is developed. The study here aims to project the enhancement in the performance of a TADTAR system by using better geometric choices and operating conditions. In the present work, by keeping the engine part unaltered, parametric variations on the refrigerator side are performed. Two geometric parameters namely resonator length and TAR stack position and one operating parameter, working gas, have been varied at three distinct choices. The performance of TADTAR is examined for three output parameters of TADTAR namely frequency of oscillations, pressure amplitude, and temperature difference across TAR stack. The present study should be useful for assisting select these parameters for starting the designing of a TADTAR. It also helps in concluding in a more generalized way the dependence of the above-said output of TADTAR on the varying parameters. This paper shows that longer resonator and He-Ar mixture as working gas among the choices is better for a TADTAR system for achieving better performance. It also highlights the potential existence of a unique position for a stack length for a TADTAR to attain maximum performance in terms of the temperature difference across the TAR stack. The present paper reports the maximum temperature difference of 16.3 K across the TAR stack.