Investigation on the delayed closure of the suction valve in the refrigerator compressor by FSI modeling

The backflow through valve due to the delayed closure, is quite difficult to predict as the effective flow area of valve is highly dependent upon the interaction between the fluid flow and the valve's motion. To solve this issue, this paper presents the simulation of the complete compression cycle of a refrigerator compressor by a three-dimensional fluid structure interaction (FSI) model. This proposed FSI model was validated by experiments, which showed that the FSI method was able to detailedly analyze the thermodynamic process during the compression cycle. Based on the FSI model, the effects of compressor rotation speed and valve parameters on the oscillation and delayed closure of the valve were investigated. The characteristic rotation speed for a reed valve was found and defined, at which the maximal delayed closure and backflow occurred. According to the simulation results, an empirical correlation to predict the characteristic rotation speed was obtained.