双吸双流道泵固液两相流动特性分析

Analysis on Flow Characteristics of Solid-liquid Two-phase Flow in Double-channel with Double-suction Pump

为研究双吸双流道泵的固液两相流动规律,本文基于CFD性能预测方法,计算泵在不同沙粒直径、不同沙粒浓度、不同流量工况的内部流动规律与外部特性曲线,并与单相流进行对比分析。研究结果表明:含沙多相流,流道中的压力梯度更大,压差分布更明显;流道内的脱流损失更严重,漩涡区域更明显,叶轮出口与蜗壳进口的动静耦合作用更剧烈;固相颗粒主要集中在叶轮的上下盖板处以及靠近蜗壳出口侧的流道区域;叶轮流道进口处的颗粒相对较少,出口处的颗粒相对较多;颗粒直径的变化对固相的离析作用明显,随着泥沙直径与流量的增大,泵的进出口总压差减小,随着泥沙浓度的增大,泵进出口总压差增大。

In order to study the solid-liquid two-phase flow law of double-channel with double-suction pump,this paper not only calculates the internal flow law and the external characteristic curves but also contrasts with the single-phase flow results in different sand diameters and different concentrations as well as different flow conditions,based on CFD performance prediction. The results show that first the pressure gradient is greater and the pressure distribution is more significantly in the flow channel than the single-phase flow. Second the flow loss is more serious and the whirlpool area is more obvious as well as the movement coupling is more intense of the impeller and volute. Third the solid particles are mainly concentrated in the upper and lower shroud as well as the outlet side of the volute. Forth the particle volume fraction is smaller at the inlet of impeller than the outlet. Last changes of the particle diameters is obvious for the solid segregation,on one hand with the increase of the sand diameter and the flow,the Inlet and outlet total pressure differences of pump is reduced,on the other hand with the sediment concentration increases,the inlet and outlet total pressure differences of pump is increases.