Performance evaluation of 10 W cooling power thermoacoustic refrigerator with spiral stacks using air and helium as working fluids

Abstract

The current research work involves the effect of different operating parameters on the performance of the thermoacoustic refrigerator. The thermoacoustic refrigerator is fabricated by using Poly Vinyl Chloride (PVC), which reduces the conduction heat loss. Two spiral stacks have been used to study the performance of the thermoacoustic refrigerator by varying the gap between two spirals (0.33 mm and 0.38 mm). The variants of spiral stacks are made up of PVC sleeves and mylar sheets of thickness 0.12 mm. In this work, Air and Helium are used as working fluids. The experiments have been carried out for different drive ratios ranging from 0.6% to 1.6%, with operating frequencies of 200–600 Hz with a step of 100 Hz. Also, the mean operating pressure of 2 to 10 bar with a step of 2 bar and a cooling load of 2 to 10 W with a step of 2 W has been considered. The temperature difference between the hot end and cold end of the stack is recorded using RTDs and Bruel & Kjaer data acquisition system. The effect of different parameters on the performance of thermoacoustic refrigerator, such as operating frequency, cooling load, mean operating pressure and drive ratios have been studied. The TAR is modeled in DeltaEC environment, simulation of significant operating conditions are analyzed and found that the results are in good agreement with experimental results. The experimental result shows that the lowest temperature measured at the cold heat exchanger is 1.12 °C by maintaining the hot heat exchanger temperature at about 32 °C when helium is used as the working fluid. Also, 30.56 °C and 28.03 °C are the highest values of temperature differences (∆T) achieved for 0.33 mm and 0.38 mm spaced spiral stacks respectively, whereas 28.56 °C and 26.04 °C are the corresponding results with air as the working fluid.