SCR系统隔膜泵瞬态流量特性分析

隔膜泵是Urea-SCR系统中使用最广泛使用的动力单元,其流量稳定性对系统计量精度有较大影响。受隔膜易变形及配流阀参数的影响,隔膜泵瞬时流量易出现较大波动。要避免或减小这种瞬时流量波动现象,必须进行隔膜泵动态特性分析。鉴于隔膜泵结构及材料特点,提出了一种双向FSI模型,经试验验证,该模型可有效预测隔膜泵动态特性。分析结果显示,减小压出阀弹簧刚度、压出阀阀芯质量及压出阀开启压力均可在一定程度上减小隔膜泵瞬时流量波动现象。所采用方法及所得结果可为相近产品的分析提供理论参考。

Instantaneous Flow Characteristics of Diaphragm Pump in Urea-SCR System

Diaphragm pump is the most widely used power unit in Urea-SCR system, and its flow stability has a great influence on system dosing accuracy. Due to the deformation of diaphragm and the influence of port valve parameters, the instantaneous flow of diaphragm pump is easy to fluctuate. To avoid or reduce instantaneous flow pulsation of the diaphragm pump, the dynamic characteristics of the diaphragm pump must be analyzed. Based on the structural and material characteristics of diaphragm pump, a two-way FSI model was proposed to simulate the dynamic characteristics of the diaphragm pump and the experimental results proved that the model can effectively predict the dynamic characteristics of diaphragm pump. The simulation results showed that reducing spring stiffness, mass of the valve core and the opening pressure of the outlet valve could reduce the instantaneous flow pulsation of the diaphragm pump to a certain extent. The method and results can provide a theoretical reference for the analysis of similar products.