Investigations of Energy Separation Effect in Vortex Tube for Different Gases

The paper aims to investigate the energy separation effect of gases such as natural gas to vortex tube. Energy separation phenomena of different gases were investigated by means of three-dimensional Computational Fluid Dynamics (CFD) method. Flow fields of natural gas, air, nitrogen, et al were simulated. The main factors that affect the energy separation were found. With cold mass fraction being 0.7 and pressure drop ratio being 3.90, the results show the effect can be divided into three intervals in terms of the freedom degrees. The first interval is filled with monatomic gas at 50 degrees C to 60 degrees C; the second diatomic gas at40 degrees C to 50 degrees C; and the third polyatomic gas at 0 degrees C to 40 degrees C. In monatomic gas and diatomic gas, the smaller the gas specific heat capacity is, the better effect will be. However, in polyatomic gas, bigger specific heat capacity ensures better energy separation.