井筒式泵装置水力特性数值模拟

基于k-ε紊流模型和雷诺时均N-S方程,运用商用CFD软件,对井筒式泵装置进行了三维流动数值仿真计算。通过对性能曲线的分析,发现设计工况下,进水管直径较大时效率较高。对比进出水损失发现,进水损失随着流量增大而增大,出水损失随着流量增大先减后增。通过分析VX云图和流线图,发现进口管直径较小时,流速较大,形成的漩涡也较大,漩涡区域涡量为大管径时的2倍以上。对叶轮进口断面轴向流速分布均匀度的分析,得到进水管较大时,叶轮进口的流速均匀度较高,但在流量超过330L/s的工况下差异不明显。从喇叭管进口断面平均涡量的计算分析中,得到喇叭管进口断面平均涡量随着流量增大而增大,且进水管直径较大时,平均涡量小,减小超过20%。

Numerical simulation of hydraulic characteristics of wellbore pump installation

Based on the k-epsilon turbulent flow model and the Reynolds-averaged N-S equation, we performed three-dimensional flow numerical simulation on the wellbore pump installation using commercial CFD software. Through the analysis of the performance curve, we found that the pump was more efficient when the diameter of the inlet pipe was larger. By comparing the loss of inlet water and outlet water, we found that the inlet water loss would increase with the flow rate, and the outlet water loss would first decrease and then increase with the increase of flow rate. By analyzing the VX cloud and flow graph, we found that when the diameter of the inlet pipe was relatively small, the flow velo city was relatively large, and the vortex was also large. The vorticity of the vortex was more than twice of that when the pipe diameter was large. Analysis on the distributio nuniformity of axial flow velocity at the impeller inlet section revealed that the flow velocity uniformity of the impeller inlet was relatively high when the inlet pipe was large, but the difference was not obvious when the flow rate exceeded 330 L/s. From the calculation of the average vorticity at the inlet section of the bell-tube, we found that the average vort icity at the bell-tube inlet section would increase with the flow rate, and it would decrease by more than20% when the inlet pipe diameter was large.