偏心距和偏心角对双吸泵径向力影响的数值分析

Numerical Analysis on Effects of Double-Suction Pump Radial Force under Different Eccentricities and Angles

为了研究双吸泵所受径向力,采用RNG k-ε湍流模型分别对原型双吸泵和重心偏移后的双吸泵进行数值模拟。通过模拟分别得出了原型双吸泵和不同偏心距和偏心角度下双吸泵外特性、中心截面以及作用在叶轮上的径向力特征,将其进行互相对比分析。研究结果表明:设计工况下,4种偏心距和4种偏心角度的扬程上下浮动范围在0%～0.5%,效率降低范围在0.08%～1.18%,小流量工况和设计工况下,偏心距越大,径向力变化越明显,越接近设计工况时,叶轮所受径向力越小;特别地,0.8Q_d,ω=180°时,F_(d=2)>F_(d=6)>F_(d=8),在ω=180°,d=4 mm时径向力出现较大范围波动。径向力较为理想的几点为:0.8Q_d下,ω=0°、1.0Q_d下,ω=270°和1.2Q_d下,ω=0°和ω=270°;通过对比设计工况下原型泵和偏心泵试验结果,表明本文所用数值计算方法及三维模型可靠性较高,进行径向力分析具有一定可信度。

In order to study the radial force of double-suction pumps,the numerical simulation of the double-suction pump and the eccentric double-suction pump was carried out using the RNG k-ε turbulence model,respectively.Through simulation,the characteristics of the prototype double-suction pump and the external characteristics,central section as well as the characteristics of radial force acting on the impeller of the double-suction pump under different eccentricity and eccentric angle were obtained, respectively,and the radial force characteristics of the impeller were analyzed by comparison with each other. The results show that: Under the design conditions,the head fluctuation range of the four eccentricities and four eccentric angles was 0%~0.5%, the efficiency reduction range was 0.08%~1.18%,under the small flow conditions and the design conditions,the greater the eccentricity,the more obvious the radial force change, the closer to the design conditions,and the smaller the radial force acting on the impeller. In particular,0.8Qd ω=180°, Fd=2> Fd=6> Fd=8,the radial force has a large range of fluctuation at ω=180°, d=4 mm.R adial force was more ideal for the following several points: 0.8Qd,ω=0°,1.0Qd,ω=270°,1.2Qd,ω=0° and ω=270°. By comparing the experimental results of the prototype pump and eccentric pump under design conditions,it is shown that the numerical prediction method of radial force and the 3D models have higher reliability and have certain degree of confidence for analysis of radial force.