Study On The Refrigeration Performance Of The Through-flow Pressure Oscillation Tube

Pressure Exchanging Refrigerator is a new generation of gas wave refrigeration equipment applying wave rotor technology. It not only has the advantages of compact structure, low manufacturing cost, but also owns high ability of operation with liquid. So far, the research on gas wave refrigeration technology has mainly been focused on reverse-flow wave rotor, not on through-flow wave rotor, which is more applied in pressure exchange. In view of the situation, this research puts forward an idea of thro ugh-flow gas wave refrigeration based on reverse-flow gas wave technology. This dissertation uses three kinds of methods including theoretical analysis, numerical simulation and analogy method of experiment for further study. The main work and conclusions are as follows:(1) The experimental platform of reverse-flow gas wave refrigerator is built to conduct experimental research on reverse-flow pressure oscillation tube. With the limited tube length and flow rate, the performance of thro ugh-flow gas wave refrigerator is superior to reverse-flow gas wave refrigerator. In consideration of similarities between them, the experimental conclusions of reverse-flow gas wave refrigerator can provide references for structural design and performance optimization of through-flow gas wave refrigerator.(2) The core component wave rotor and its parts nozzles of thro ugh-flow gas wave refrigerator are designed. According to the wave theory of gas dynamics, an ideal wave pattern of through-flow wave rotor is set up and the analytical model of wave system in four-port through-flow gas wave refrigerator is built. The calculation program is written based on the analytical model, which is used for obtaining the quantitative relations of waves in pressure oscillation tubes, predicting port arrangement of the wave rotor and the distance of interface moved. This analytical model can be the theoretical basis for the follow-up design and performance optimization of through-flow gas wave refrigerator.(3)The 2D numerical model of the through-flow gas wave refrigeration is established and flow characteristics in the pressure oscillation tube are studied by using the method of numerical simulation by means of the software CFD. Discussing the factors which influence the performance of through-flow gas wave refrigerator, according to different parameters of structure and operation, utilizing numerical calculation to analyze the influence of single parameter on the performance of through-flow pressure oscillation tube. The result provides the numerical basis for structure optimization of gas wave refrigerator. Through this, the optimal working wave pattern is built. For parameters of port arrangement and the distance of interface moved, the relative errors between the optimum simulation results and the analytical results are very small, respectively lower than 12% and 1.5%, which proves the effectiveness of the calculation program.(4) Analyzing refrigeration characteristics of through-flow pressure oscillation tube, and-a detailed study about the distance of interface moved, external pre-cooling cycle and leakage is done. Through the comparison of the theoretical isentropic expansion efficiency between through-flow gas wave refrigerator and reverse-flow gas wave refrigerator, the deviation is lower than 2%, which proves the refrigeration performance is almost same. According to the phenomenon of gas mixing and reverse compression in thro ugh-flow pressure oscillation tube, there is one optimization scheme which is to add a mid-temperature outlet after high-temperature port, which improves the performance of thro ugh-flow gas wave refrigerator.