Temperature and Pressure Measurements at Cold Exit of Counter-flow Vortex Tube with Flow Visualization of Reversed Flow

In order to clarify the structure of the cold flow discharged from the counter-flow vortex tube(VT), the temperature and pressure of the cold flow were measured, and the existence and behavior of the reversed flow at the cold exit was studied using a simple flow visualization technique consisting of a 0.75mm-diameter needle, and an oil paint droplet. It is observed through this experiment that the Pitot pressure at the cold exit center can either be lower or higher than atmospheric pressure, depending on the inlet pressure and the cold fraction, and that a reversed flow is observed when the Pitot pressure at the cold exit center is lower than atmospheric pressure. In addition, it is observed that when reducing the cold fraction from unity at any arbitrary inlet pressure, the region of reversed and colder flow in the central part of cold exit extends in the downstream direction.

进口压力对涡流管冷却特性影响的实验研究

为了解决燃气轮机高温部件热防护问题,采用实验研究涡流管在不同进口压力(0.20~0.65 MPa)和冷气流率(0.17~0.89)下的冷却特性。实验结果表明:实际温降,在不同进口压力下随着冷气流率的增加先增大后减小,在相同冷气流率下随着进口压力的增大而增大;温度效率,在不同进口压力下随着冷气流率的增大先增大后减小,在冷气流率等于0.5时达到最大值;绝热效率,在进口压力等于0.20 MPa时最小,在大于0.30 MPa时随着进口压力的增加变化不大;制冷效率,随冷气流率的增加会先增加后减小,进口压力等于0.30和0.40 MPa时制冷效率最高。