涡旋压缩机径向迷宫密封中泄漏气体气动热力行为研究

以涡旋压缩机径向迷宫密封为研究对象，分别用宏观能量法和黏性流动理论计算该密封的泄漏量，通过泄漏量理论值与实测值的对比，以期探寻泄漏气体的气动热力行为。在假设无透气效应和泄漏气体在迷宫槽中作等压恒温恢复的条件下，建立求解泄漏量的数理方程；在考虑透气效应与非等压恒温恢复的条件下，利用热力过程方程与黏性流动理论推导出透气流是否达到声速的判别式及临界气速、临界密度、泄漏量的计算式。将两种算法所得泄漏量与实测泄漏量对比研究发现，直通型迷宫密封中气体泄漏过程是膨胀吸热过程，膨胀过程指数随相邻压缩腔压差的增大而减小；泄漏是由透气流与相邻迷宫槽间的二维泊肃叶流共同作用形成的，透气效应随相邻压缩腔压差的增大而更加明显；用黏性流动理论求解泄漏量具有较高的计算精度。

Research on Gas Leakage Pneumatic Thermodynamic Behavior in the Radial Labyrinth of Scroll Compressor

The scroll compressor’s radial labyrinth sealing is regarded as the research object, by using the macro energy method and the theory of viscous flow, the leakage for the sealing structure are calculated, to find aerodynamic and thermodynamic behavior of gas leakage. A comparison is made between experimental results and theoretical predictions. Assuming that there is no ventilation effect and the gas do isobaric and isothermal recovery in the labyrinth groove, the mathematical equation of leakage is established; while considering the ventilation effect and non isobaric isothermal recovery, by using thermodynamic equation and the theory of viscous flow, discriminant for judging whether ventilation flow comes up to speed of sound is deduced, and the algorithm to calculate critical velocity, critical density and leakage is proposed. The different between experimental results and theoretical predictions of leakage is analyzed. The result indicates that leakage process in straight through labyrinth sealing is expansion process accompanied with absorption of heat. The thermodynamics index decrease obviously with the increase of the pressure differences of two adjoining pressure chamber, and the leakages is composed of ventilation flow and 2D Poiseuille between in adjoining labyrinth groove, ventilation effect become also clearer with the increase of the pressure differences. The algorithm with theory of viscous flow for leakage has high computational precision.