The Influence Of Pulse Jet On Performances Of Pressure Wave Refrigerator

Pressure wave refrigerator is a new kind of refrigerating equipment using the shock wave movement to transform gas pressure energy into heat energy. It has been widely used in industrial areas for many advantages. Pulse jet is the need of gas charge and exhaust for pressure wave refrigerator, and it also has some important influence on the performance of pressure wave refrigerator. In this dissertation, the pulse jet style, the influence on the shock wave, the flow in the tube and the cooling effect was deeply studied theoretically and experimentally.The influence of the pulse jet style on the forming of shock wave and the shock wave intensity was explored. The initial disconnection style in oscillating tube vented and the initial disconnection breakdown was proposed by different pulse jet style. The mathematical expression of the parameter of gas charge and discharge and the mach number of shock wave was established. Three reason of the forming of shock wave and the style of pulse jet and its working state was analyzed. The characteristic of the forming of shock wave in the tube and the influence of the shock wave intensity on cooling effect was also analyzed in working time. The reason why the cooling efficiency was lower in low rotate speed and has no change in high rotate speed was revealed.The coupling from the pulse jet in the nozzle to the unsteady flow in the tube was discussed. And the relations between the parameters of gas charge and discharge, structure, working, flowing in tube and ideal cooling efficiency were established. The theory foundation of the influence of pulse jet on the flowing in the tube and characteristic would be built.And then, some improvements have been made on the old single tube pressure wave refrigerator experimental system. The experimental research, such as the ratio of gas charge time to gas exhaust time(ζ), the frequency of the jet flow(f),the ratio of the expansion(ε),the length of the tube(L)and the heat transfer condition, has been carried out on the improved experimental system. The results were drawn as the following: the refrigerating efficiency will be heightened by augmentingεwhenζis in 0.0405 to 0.1842;the highest cooling efficiency will be...