基于CFD的舌簧排气阀流动特性研究

摘要

气阀是活塞式压缩机最为关键的部件，其工作性能直接影响压缩机的能效。本文首先对气阀的流动特性进行分析，然后基于CFD的方法，在Fluent中模拟了舌簧排气阀稳态和瞬态流动时的压力场、速度场的分布，对造成气阀压力损失的流截面比、扩散角以及阀片升程这些因素进行分析。研究表明：较小的通流截面比和扩散角有利于减小气阀压力损失；较大的阀片升程虽然能降低阀隙速度，明显减小气阀压力损失，但是过大的升程不能有效降低压力损失，反而会增加阀片的磨损，减少阀片的使用寿命。最后，论文以某型号压缩机为例，实验验证了仿真分析结论的正确性。通过对舌簧排气阀流动特性的分析，为气阀优化设计、提高气阀效率提供了参考依据。%The reed type valve is a key component of reciprocating compressors affecting the efficiency and reliability of the machines. This paper analyzed the flow characteristic firstly, and then simulated the distributions of pressure field and velocity field in the steady and transient flows based on the CFD method, where the effects of those parameters, such as flow section ratio, spread angle and valve lift, on valve pressure loss were investigated. The results showed that a small flow section ratio and a small spread angle may reduce the pressure loss of the discharge valve. But due to the limitation of valve plate design space, the small values of these two parameters couldn′t be ob⁃tained easily. Although the higher valve lift could reduce the pressure loss effectively, which increased the reed wear and reduced the reed life. The reasonable valve lift can be obtained by the CFD method. The study of the flow characteristic could provide basis for the optimi⁃zation design of reed valve.