Reciprocating compressor, reed valves, valve dynamics, valve reliability.
Reed-type valves are used to control the suction and discharge processes in small reciprocating compressors. Simulation models adopted in the preliminary design of such compressors usually employ the concepts of effective force and flow areas to characterize valve performance. These parameters are evaluated considering steady flow through the valve port, and hence neglecting flow inertia in the opening and closing stages of the valve motion. Moreover, both effective areas are also considered not to be affected by the presence of backflow. This paper presents a numerical study about the effect of flow inertia and backflow on the effective flow and force areas of valves of a small reciprocating compressor, with a finite element model developed to predict valve dynamics. The results show that the effective force area must be evaluated separately for conditions of normal flow and backflow and that flow inertia can significantly affect backflow in the valve.