后掠式叶轮污泥回流泵的优化设计与数值模拟

The Optimal Design and Numerical Simulation of the Swept-Back Blade Sludge Return Pump

摘要: 针对污泥回流泵在污水中缠绕问题，设计了20˚、40˚、60˚三种后掠角的叶片；针对机组效率低下的问题，重新设计了节段式、扭曲式两种导叶。基于RNG k-ε湍流模型与SIMPLE算法分别从外特性和内部流场分布方面对比分析了优化前后水泵性能情况。数值模拟结果表明：随着叶片后掠角的增加，污泥回流泵扬程与轴功率均下降，随着后掠角度变大，下降幅度也变大；后掠角为20˚的污泥回流泵效率曲线较平稳，高于原型泵。扭曲导叶的改型使得污泥回流泵的扬程和效率都得到了大幅提高。

Abstract: In view of the return sludge pump’s winding problem in the sewage, this paper designs three sweepback angles of blades: 20˚, 40˚, 60˚; Aiming at the problem of low efficiency of the unit, two types of guide vanes: segmental type and twisted type, are redesigned. This paper compared and analyzed the performance of the pump before and after optimization separately from the external characteristics and the internal flow field distribution based on RNG k-ε turbulent model and SIMPLE algorithm. Numerical simulation results show that with the increase of the blade swept angle, the lift and shaft power falls and as the Angle increases, so does the drop; the efficiency curve of 20˚ back swept blade is smooth and higher than that of the prototype pump. The modification of the distorted guide blade has greatly improved the lift and efficiency of the reflux pump.