半开式复合叶轮多级离心泵设计与性能预测方法研究

发布时间：2018-03-10 20:47

本文选题：低比转速　切入点：多级离心泵　出处：《浙江大学》2011年硕士论文　论文类型：学位论文

【摘要】：AP1000化容补水泵等特殊低比转速多级离心泵在性能上不但具有小流量高扬程的特点,还需保证从关死点到最大流量的多个工况的性能同时达到使用要求。同时,结构的紧凑性,以及小流量不稳定和大流量过载等问题也是低比转速泵设计需要重点关注的问题。本文为形成结构紧凑、稳定性好、满足多工况性能要求的低比转速多级离心泵设计方法,以AP1000化容补水泵为实例,研究半开式多平衡孔复合叶轮和涡形双流道导叶的性能,建立其三维流场模拟和性能预测方法,基于计算流体动力学(CFD)技术改进设计了满足多工况性能要求的水力模型。探讨了低比转速多级离心泵半开式叶轮、复合叶轮和导叶的设计原理和方法,给出关键参数的确定方法,分析了半开式直叶片复合叶轮和涡形双流道结构的设计要点。给出了半开式叶轮离心泵全流道三维流动数值模拟方法,以单级半开式叶轮离心泵为模型,考虑叶轮前后间隙、平衡孔、口环间隙等结构,分析不同建模形式、湍流模式、离散方法对性能曲线预测计算精度的影响,完善和验证了基于三维流动模拟的性能预测方法。为满足AP1000化容补水泵四个特殊工况点的性能和结构紧凑型要求,设计了半开式多平衡孔复合直叶片叶轮和涡形流道式导叶结构,建立了包含叶轮、导叶、叶轮前后间隙、密封口环和平衡孔的三维全流道实体模型。基于本文验证的流场三维数值模拟方法,预测全工况下的水力性能,分析了决定低比转速多级离心泵各工况性能的关键参数。基于模拟结果给出了改善低比转速多级离心泵性能的结构或设计建议,并改进了过流部件结构,使AP1000化容补水泵模型满足多工况运行可靠和大流量不过载的设计要求。本文给出的多级离心泵叶轮与导叶的设计方法,以及相应的三维流动数值模拟和性能预测方法,水力性能上满足了多工况运行的要求,对低比转速多级离心泵研究与核电系统补水泵研发具有一定意义。
[Abstract]:The special low specific speed multistage centrifugal pump such as AP1000 pump not only has the characteristics of small flow rate and high head, but also needs to ensure that the performance of multiple working conditions from dead point to maximum flow rate can meet the operational requirements at the same time. At the same time, the structure is compact. The problems of small flow instability and large flow overload are also important problems in the design of low specific speed pump. In this paper, the design method of low specific speed multistage centrifugal pump with compact structure, good stability and satisfying the performance requirements of multiple working conditions is presented. Taking AP1000 capacitive pump as an example, the performance of semi-open multi-balanced hole composite impeller and vortex-shaped double-channel guide vane is studied, and the three-dimensional flow field simulation and performance prediction method are established. Based on the computational fluid dynamics (CFD) technique, a hydraulic model was designed to meet the requirements of multi-condition performance. The design principle and method of semi-open impeller, compound impeller and guide vane of multistage centrifugal pump with low specific speed are discussed. The determination method of key parameters is given, and the design essentials of semi-open straight vane composite impeller and vortex double-channel structure are analyzed. In this paper, a numerical simulation method of three-dimensional flow in the full passage of semi-open impeller centrifugal pump is presented. Taking the single-stage semi-open impeller centrifugal pump as a model, considering the structure of the impeller's front and back clearance, the balance hole, the clearance of the mouth ring, and so on, the different modeling forms and the turbulence model are analyzed. The effect of discrete method on the accuracy of performance curve prediction is improved and verified. The performance prediction method based on 3D flow simulation is improved and validated. In order to meet the performance and structural compact requirements of four special working conditions of AP1000 capacitive water pump, a semi-open multi-balanced hole composite straight blade impeller and a vortex runner guide vane structure are designed, and the front and rear clearance of impeller, guide vane and impeller are established. Based on the 3D numerical simulation method of the flow field verified in this paper, the hydraulic performance of the whole working condition is predicted. The key parameters determining the performance of low specific speed multistage centrifugal pump are analyzed. Based on the simulation results, the structure or design suggestions for improving the performance of low specific speed multistage centrifugal pump are given, and the structure of overflowing parts is improved. The AP1000 capacitive pump model can meet the design requirements of reliable operation and high flow rate. The design method of multi-stage centrifugal pump impeller and guide vane, and the corresponding three-dimensional flow numerical simulation and performance prediction method are given in this paper. The hydraulic performance meets the requirements of multi-condition operation. It has a certain significance for the research of low specific speed multistage centrifugal pump and the research and development of nuclear power system feedwater pump.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH311

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