Investigation of the friction-induced vibration of a novel four-way reversing valve using spectral kurtosis and number of peaks spectrum

Abstract FWRVs (Four-way reversing valves) are widely used to switch operating conditions in air conditioner systems. Most previous research focused on the efficiency of the FWRVs in heat pump systems. However, the vibrations during the valve reversing processes are not yet well investigated. The friction-induced vibration (FIV) is generated when the slider slides on the valve seat under the high pressure in the valve chamber. In this study, an novel FWRV is proposed to reduce the FIV and improve the fluency during the valve reversing process. The pressure change in the chamber is obtained using CFD (computational fluid dynamics) simulations. Experimental tests are performed to analyze the performance of the novel FWRV. Short-term RMS is employed to evaluate the vibration energy from the measured signal. The FIV acceleration signals generated in FWRV reversing process are periodic impulsive vibrations. A new method named SKNPS (Spectral Kurtosis and Number of Peaks spectrum), which is based on the decomposition criterion of Spectral Kurtosis (SK) and Number of Peaks (NP), is proposed to further analyze the duration of the reversing process. The results indicate that the vibrations of the novel FWRV are reduced and the reversing process is more fluent compared with the prototype valve.