不同转子轴向间隙下双螺旋轴流泵的内部流动特性

Internal Flow Characteristics of Double Helical Axial Flow Pump Under Different Rotor Axial Clearances

通过改变两螺旋转子之间的轴向间隙(1、5、10 mm),研究双螺旋轴流泵在不同转子轴向间隙下的内部流动特性。基于CFD模拟平台,采用浸入实体法,运用N-S方程和标准k-ε湍流模型,对不同轴向间隙和不同工况下的瞬态特性进行数值模拟,得到双螺旋泵在不同转子间隙下各过流部件在运转过程中的瞬态流动特性。结果表明:转子间隙为1 mm时泵的扬程最高,增大转子间隙(5和10 mm)泵的扬程依次减小;1 mm间隙下泵的升压性能最好,但流体在刚进入转子域出现了明显的负压现象,间隙增大后转子内抗堵塞能力增强,负压现象得到改善;双螺旋轴流泵的主要泄漏区域在转子啮合区,随着转子轴向间隙的增大,啮合区的速度增大,出现较明显的泄漏;双螺旋泵的扬程与流量成反比,随着设计流量的增大,3种间隙泵的扬程均逐渐减小。

In this paper,the internal flow characteristics of the double-helix axial flow pump under dif-ferent axial clearances of the rotor are studied by changing the axial clearance between the two spiral rotors(1,5,10 mm).Based on the CFD simulation platform,the immersed solid method was used.The N-S equa-tion and the standard k-εturbulence model were used to numerically simulate the transient characteristics under different axial clearances and different working conditions,and the transient flow characteristics of each flow component of the double-helix pump under different rotor clearances were obtained.The results show that the head of the pump is the highest when the rotor clearance is 1 mm,and the head of the pump decreases with the increase of the rotor clearance(5 mm and 10 mm).The booster performance of the pump is the best under the 1 mm gap,but the fluid has obvious negative pressure phenomenon when it just enters the rotor domain.After the gap increases,the anti-blocking ability in the rotor is enhanced and the negative pressure phenomenon is improved.The main leakage area of the double helical axial flow pump is in the ro-tor meshing area.With the increase of the axial clearance of the rotor,the speed of the meshing area in-creases,and the leakage is obvious.The head of the double screw pump is inversely proportional to the flow rate.With the increase of the design flow rate,and the head of the three gap pumps gradually decreases.