肘形进水流道几何参数对轴流泵装置性能影响的数值模拟研究

发布时间：2018-04-02 05:14

本文选题：泵装置　切入点：肘形进水流道　出处：《扬州大学》2011年硕士论文

【摘要】：进水流道是泵站前池和水泵叶轮室之间的一个过渡段,是为了使水流从前池到进入叶轮室的过程中能够更好的转向和加速,以尽量满足水泵叶轮室进口所要求的水力设计条件。进口流态不好,将直接影响叶轮室内水流流态,可能会产生脱流等现象,从而影响水泵装置性能。为了让泵装置获得较好的性能,设计出参数较合理的进水流道从而获得较好的水流流态是十分必要的。肘形进水流道是大中型轴流泵站比较常用的一种进水流道形式。本文以某泵站肘形进水流道设计尺寸为背景,首先对整套轴流泵装置进行数值模拟计算。在计算时采用的控制方程是雷诺时均方程(N-S方程),紊流模型为RNG K-ε模型,算法为SIMPLEC算法。通过对不同工况下的泵装置进行的数值模拟研究,得出了水流在泵装置内部流动流态、压力分布以及泵装置外特性,并与试验结果进行了对比,发现结果非常接近,说明数值模拟的方法比较可靠。为了分析不同几何参数下的肘形进水流道对泵装置性能的影响有何不同,本文通过改变肘形进水流道三个主要基本参数,共设计出27个方案,对每个方案3个工况进行数值模拟研究。通过数值模拟计算,得出了叶轮进口(即出水流道出口)断面流场和轴向流速分布均匀度,以及不同方案下的泵装置效率和扬程,从而得出结论：设计肘形进水流道时,可以尽量取L/D、H/D范围的上限值(其中L/D范围是3.5～4.5,H/D范围是1.5～2.0),B/D取值2.256～2.5均可,可以得到使泵装置获得较好性能的肘形进水流道。
[Abstract]:The inlet passage is a transitional section between the front pool of the pump station and the impeller chamber of the pump to enable better steering and acceleration of the flow from the former pool to the impeller chamber. In order to satisfy the hydraulic design conditions required by the inlet of the pump impeller chamber as far as possible, the bad inlet flow pattern will directly affect the water flow pattern in the impeller chamber and may result in the phenomenon of deflow, etc. In order to make the pump device obtain better performance, it is necessary to design the inlet passage with reasonable parameters so as to obtain a better flow pattern. The elbow inlet passage is one of the common inlet channels in large and medium-sized axial flow pump stations. This paper takes the design size of the elbow inlet passage of a pump station as the background. The control equation used in the calculation is Reynolds time average equation and N-S equation, and the turbulent model is RNG K- 蔚 model. The algorithm is SIMPLEC algorithm. Through the numerical simulation of the pump device under different working conditions, the flow state, pressure distribution and the external characteristics of the pump device are obtained, and the results are compared with the experimental results. The results are very close, indicating that the numerical simulation method is more reliable. In order to analyze the influence of elbow inlet passage on pump performance under different geometric parameters, 27 schemes were designed by changing the three main parameters of elbow inlet passage. The flow field and axial velocity distribution uniformity of impeller inlet (i.e. outlet outlet) section, as well as pump device efficiency and head under different schemes are obtained by numerical simulation. It is concluded that the upper limit value of the L / D / D / D range can be taken as far as possible when designing the elbow inlet channel (where the L / D range is 3. 5 / 4. 5) and the L / D range is 1. 5 / 2 / 2 / 2 / B / D = 2. 256 / 2. 5. The elbow inlet flow channel with better performance can be obtained.
【学位授予单位】：扬州大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH312

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