Dynamic Behavior of Valves with Pneumatic Chambers for Reciprocating Compressors

Abstract

This paper describes the dynamic behavior of valves with pneumatic chambers for reciprocating compressors. These are known as “damped valves” and are capable of reducing the impact on the valve seat and valve stopper. The characteristics of the dynamic behavior of the damped valves were clarified by calculating newly derived governing equations of valve dynamics. From the calculated results, it becomes apparent that the volume of the pneumatic chambers and the clearance between the pneumatic chamber and the valve have a large influence on the impact speed of the valves. Furthermore, the valves tend to close later for a higher compressor speed to oscillate at a larger amplitude for a lower density of gas such as hydrogen. These tendencies show that the selection of the specification of damped valves is very important. The stiffness of the valve spring and the lift of the valve also affect valve behavior as with valves without pneumatic chambers.