【作者】 王光辉；

【导师】 丛小青；

【作者基本信息】 江苏大学 ， 流体机械及工程， 2010， 硕士

【摘要】 长轴泵广泛应用于农田排灌、防洪、排涝、污水处理、电站(燃煤电站、核电站、蓄能电站、潮汐电站)、冷却系统等各个领域。然而由于其自身结构的特殊性,导叶式长轴泵普遍存在着性能低下、主轴容易断裂和振动剧烈等问题。因此如何提高其性能和泵轴的可靠性分析是当前研究的重要方向。本文对带有空间导叶的船用长轴泵的设计优化方法、内部流场和泵轴可靠性分析进行了较为系统的研究,主要内容和结论如下：1介绍长轴泵的水力设计及优化方法,并以JLY-80-27型泵为研究对象,通过数值计算详细分析了不同喉部面积、导叶叶片出口安放角和导叶叶片数对泵性能的影响。针对所要设计的船用泵,将叶轮和空间导叶作为一个整体,对空间导叶的主要性能参数进行合理设计和优化,最后利用PRO/E绘图软件生成叶轮、空间导叶的三维实体及整个流道计算区域。2利用FLUENT软件对其内部流场进行数值模拟,分析整个流道、叶轮、环形空间、空间导叶及其内外盖板的内部流场。结果发现：(1)叶轮进口出现负压,该区域将有可能发生空化。(2)环形空间内流动紊乱,产生较大的冲击损失。(3)导叶工作面和背面的流速从导叶进口处至导叶出口处呈现增大—减小趋势,在导叶中部附近达到最大,导叶背面出现二次流。(4)导叶内外盖板上出现不同程度的漩涡,说明空间导叶内流动相当混乱,存在着复杂的流动状态。3分别以二硫化碳和水为输送介质,计算了不同流量下该泵的流场情况,并把计算结果与试验结果对比分析。结果表明：计算和实测的特性曲线总体趋势是一致的,扬程和效率有了明显的提高；相同流量下数值计算结果和试验数据的最大误差基本小于18%,证明了数值计算和优化方法的有效性,得到的结果符合设计要求；相同流量下,介质为二硫化碳的计算扬程和效率略高于介质为水时的计算扬程和效率。4基于ANSYS有限元软件和传统的泵轴校核理论,对泵轴进行了静力和疲劳强度分析,根据所得危险点的主应力值对泵轴进行了校核,并对泵轴的变形情况以及振动状况作了分析和研究。更多还原

【Abstract】 The long axis of pumps are widely used in agricultural irrigation, flood control, drainage, sewage treatment, power station(coal-fired power plants, nuclear power stations, storage power and tidal power plants), cooling system and other fields. However, because of their special structure, the long axis of pumps with guide vane exist poor performance, shaft fracture and severe vibration problems generally. So how to improve the performance and the reliability of the shaft are currently important research directions.The design optimization and flow field of the marine long axis of pump with a space guide vane and the reliability analysis of shaft were studied systematically in the paper. The main contents and conclusions are as follows:1 The hydraulic design and optimization of the long axis of pump were introduced. Based on a JLY-80-27-type pump as the research object, a detailed analysis of different throat area, blade exit angle of guide vane and number of guide vane blades on the influence of the pump’s performance was done by numerical calculation. For the designed marine pump, the impeller and space guide vane were put as a whole and the main performance parameters of the space guide vane were carried on reasonable design and optimization. Finally, the impeller, space guide vane and computational domain of the whole flow were generated by PRO/E.2 The internal flow field was simulated by FLUENT software. The flow distributions of the whole flow, impeller, annular space, space guide vane and its internal and external cover were analyzed. The results show that:(1)The inlet of impeller appears negative pressure, where cavitation will occur. (2)The flow in annular space is chaotic, which has a great impact on loss. (3)The velocity of flow in the face and back of the guide vane shows an increase-decrease trend from the inlet to the exit, which reaches the maximum near the middle of the guide vane. The secondary flow emerges in the back of guide vane. (4)There are different degrees of swirl in its internal and external cover of the guide vane, which shows the flow is rather chaotic and complex.3 Carbon disulfide and water were used for conveyance medium respectively and the flow field conditions under different flows of the pump were calculated. The calculated results and experimental results were compared and analyzed. The results indicate that:The overall trend of characteristic curve between calculation and test is consistent and the head and the efficiency increase obviously; The maximum error is basically less than 18% in the same flow between numerical calculation results and experimental data, which proves the effectiveness of the numerical calculation and optimization. The obtained result complies with the design requirements; The calculated head and efficiency when the medium is carbon disulfide are slightly higher than that when the medium is water under the same flow.4 Based on ANSYS software and traditional checking theory of pump shaft, the pump shaft was conducted for static and fatigue strength analysis. The pump shaft was also checked according to the danger point of principal stress value.The deformation and vibration circumstances of the pump shaft were analyzed and studied.更多还原