A large solar/heat‐driven thermoacoustic cooler

Based on the success of an earlier solar‐powered thermoacoustics prime mover which used a direct‐illumination stack and no hot‐side heat exchanger [Chen and Garrett, Proc. 16th Int. Cong. Acoust., Vol. II, 813–814 (1998)], a large solar/heat‐driven thermoacoustic cooler was designed and fabricated. Target cooling powers of 10 to 60 W, over a 25‐deg temperature span, were based on a thermal input power of 150 to 600 W. To concentrate the required amount of solar power on an 11‐cm‐diameter ceramic stack, a 10‐ft diameter fiberglass parabolic dish, used for satellite TV, has been converted by gluing aluminized MylarTM on its surface over a 2‐m diameter. A two‐axis coordinated solar tracking system, driven by two computer‐controlled motors, has produced the required 600 W of solar power to illuminate the hot side of the stack for a maximum of 3 h. Measured performance of the solar refrigerator will be compared to DeltaE models. [Work supported by the Office of Naval Research.]