Numerical model and investigations of reed valve motion characteristics of reciprocating compressor

  • guangyu mu
  • feng wang
  • xiaozhen mi
Keywords: Reciprocating compressor, reed valve, motion characteristics, displacement measurement system

Abstract

Reed valve is a key component of reciprocating compressors affecting the efficiency and reliability of the refrigeration system. In order to further investigate the influence of structural parameters on reed valve motion characteristics, theoretical and experimental analysis of a discharge valve dynamic behavior are carried out in this paper. Firstly, the dynamic models of discharge valve and suction valve based on energy conservation are established. Valve displacement, velocity and other transient motion characteristics can be analyzed by using the new model. Secondly, in order to verify the validity of the new model, the displacement testing system of a discharge valve is established. The experimental results show that the measured displacement curve is well agreement with the calculation curve. It means that the new model can be used to analyze the motion law and dynamic characteristics of the valve effectively. Thirdly, the effects of valve lift, stiffness coefficient and effective flow area on delayed closing angle, fully open period and maximum impact speed are investigated. The results show that when the valve lift is increased from 1.5 mm to 4mm, the closing angle is decreased from 362 degrees to 349 degrees. When the lift is 3mm-3.7mm, the maximum impact speed of the valve increased slowly, and closed timely. So the reasonable valve lift range is 3mm - 3.7mm. In addition, valve’s thickness has a direct effect on its stiffness coefficients. Valve plate flutter occurs when stiffness coefficients is more than 5000N/m, so the valve thickness cannot be designed more than 0.64mm accordingly. Moreover, with the reduction of effective flow area, the valve gradually closed delay. The effective flow area is not only affected by the diameter of valve port, but also the lift, the form of valve plate, cylinder diameter and other factors. Therefore, it is necessary to comprehensively consider these factors to increase the effective flow area. The researching on the motion law of reed valve can provide the theoretical basis for the rational optimization of valve structure.

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Published
2019-11-20
Section
Mechanical Engineering (1)