Zhileng xuebao (Jan 2014)
The Structure of Gas Distribution on the Flow in and the Performance of Pressure Wave Refrigerator
Abstract
The influence of some structural factors, i.e. the nozzle style, relative gas charge time on the flow in and the performance of pressure wave refrigerator are studied theoretically and experimentally in this paper. The results show that the strength of incident shock wave is the strongest when using the contraction nozzle, follows by using the laval nozzle, and is the weakest when using the uniform nozzle when the ratio of the expansion ε is from 2.0 to 12.0. Thus the cooling effect of pressure wave refrigerator is the strongest when using the contraction nozzle. The maximun refrigerating efficiency ηmax is increased first and then decreased when the relative gas charge time τ is increased. The optimum relative gas charge time τ is about 0.06 when the ratio of the expansion ε is 4, the ratio of length to diameter L/d is 400 and the relative depth of the jet hole in gas distribution is 0.55. When τ>0.075, the optimum pulsing frequency (fopt) is on the second peak of the refrigerating efficiency , while fopt is on the third peak of the refrigerating efficiency when τ>0.075.
