Investigation on dynamic characteristics of a plate-type discharge valve in a diaphragm pump for SCR system by two-way FSI model

Abstract

A plate-type port valve with rubber valve plate in a miniature diaphragm pump is presented. To investigate the dynamic characteristics of this type of discharge valve, a two-way fluid structure interaction model is proposed. The interaction between the dynamic behavior of the fluid and rubber is considered in the fluid structure interaction model. Based on the fluid structure interaction model, the internal flow of the pump, the deflection of the diaphragm and discharge valve plate is calculated. To verify the validity of the numerical model, a prototype pump is fabricated and tested. The experimental pressures in the working chamber of the pump show the same overall trends with the numerical results. The deviations between the numerical and experimental flowrates are less than 7.2%. The experimental results prove that the numerical model is effective in predicting a complete discharge process of the pump. There is a big difference between the deflection of the center of the valve plate and the edge of the valve plate. The oscillation period of the pressure in the working chamber of the pump is approximately double that of the discharge valve plate. When the pump speed is lower than 2500 r/min, it has little influence on the lag angles of the discharge valve under rated pressure. The lag angles at rated pump speed increase when the backpressures increase. The stress of the discharge valve plate reaches a peak when the valve plate impact on the valve limiter or valve seat.