转套式配流系统闭死角对工作脉动的影响研究

Influence on Working Pulsation of Closed Angle of Rotating-Sleeve Distributing-Flow System

为了降低转套式配流系统在转换过程中出现的冲击现象和噪声,本文根据配流系统配流特征,分析了泵腔在两个阶段中闭死升压和降压的数学模型。同时,为改善配流系统工作中液压冲击现象,选取最佳闭死角,并利用仿真软件Fluent,对配流系统工作循环中流量和压力变化进行数值模拟。仿真结果表明,当闭死压缩角为3°时,对流量特性及泵腔压力脉动的影响最小,且最接近理论分析;在任意膨胀阶段,泵腔内部都出现了不同程度的空化现象,且膨胀角越小,流量脉动越大,综合考虑膨胀角选取2°最合适。该研究为转套式配流系统确定闭死角的大小提供了理论依据。

In order to decrease impact and noise in the conversion process of rotating-sleeve distributing-flow system,the mathematical models of pre-loading and pre-depressurization in piston pump are established based on distributing-flow characteristics.And we choose the best dead angle and simulate the distributing flow fluid model using software Fluent to improve the hydraulic shock.As a consequence,the results show that the compression angle 3°is closest to theoretical value and has the minimum influence on flow and pump pressure characteristic.On the other hand,pump chamber appears cavitation phenomenon on a certain degree and the flow pulsation is smaller with greater expansion angle.So the expansion angle 2°is more suitable to distributing-flow system.The study concretely provides the theoretical foundation for ensuring the size of closed angle.