Effect of gas spacing and resonance frequency on theoretical performance of thermoacoustic refrigerators

Abstract

AbstractIn this paper, the design and analysis of 500 W thermoacoustic refrigerators for the temperature difference of 28 K using helium and air are discussed. Helium is the best working gas, but air is chosen to study the possibility of replacing helium for the future cost-effective refrigerator since it is much cheaper than helium. Heat and work flow equations of thermoacoustic refrigerators are discussed. The refrigerator models are optimized by normalizing the design parameters using Rott’s linear thermoacoustic theory. The effect of gas spacing expressed in terms of the thermal penetration depth in stack-heat exchanger unit at 85% porosity is discussed. The effect of the resonance frequency of air on the stack-heat exchanger sheets spacing and thickness and on the theoretical performance is discussed. The effect of the resonance frequency of air on the theoretical performance at 200 Hz, 300 Hz, and 400 Hz is discussed. The cooler shows better COP of 1.72 at 300 Hz for air and 1.53 at 400 Hz for helium. The theoretical results are compared with the DeltaEC software results. The DeltaEC predicts cooling power and COP of 347 W at 1.02 for helium and 224 W at 0.79 for air, respectively.