悬臂式多级离心泵间隙流及其动力特性研究

发布时间：2018-03-16 16:53

本文选题：悬臂式多级离心泵　切入点：间隙流　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：悬臂式多级离心泵紧凑结构,广泛地应用于军用、民用中对空间要求较为苛刻的领域。但由于叶轮转子和导叶被布置在远离轴承支撑的一侧,悬臂式多级泵转子系统在不平衡激振力作用下极易产生径向挠度,出现不稳定涡动现象。然而存在于盖板侧及口环的间隙泄漏流是重要的激励源之一,因此,间隙泄漏流动对于悬臂式多级泵的影响不容忽视,开展间隙流动状态及其动力特性的研究很有必要。本文以M220型悬臂式多级离心泵为研究对象,对其间隙流动、间隙动力特性以及间隙流对转子稳定性的影响进行了较为深入的研究,并在此基础上开展了一系列针对间隙流对转子性能影响的试验研究。本文主要工作和研究成果有:(1)基于CFX 14.5对带有间隙泄漏的多级离心泵全流场进行定常计算,模拟预测值与试验值吻合较好,验证了数值模拟的准确性。分析了各工况下间隙流动对泵体内部主流场的影响,其中小流量工况下间隙流对主流静压分布、速度分布和湍动能分布的影响最为明显。(2)基于M220间隙泄漏模型构造了4种间隙流道,通过研究压力脉动的方式寻找间隙流能量分布与间隙结构的关联性。研究发现口环和级间间隙的存在增加了前后泵腔的主频幅值,带口环的前泵腔压力脉动沿间隙流道从外径向内径有所增强,带级间间隙的后泵腔压力脉动则相反。(3)基于CFD方法对悬臂式多级离心泵叶轮在不同轴向位移下泵的外特性、能量特性、前盖板侧间隙流场、间隙的压力脉动及叶轮径向力轴向力进行了研究。通过对比,发现前泵腔间隙变化对外特性和径向力影响较大,后泵腔间隙变化则对轴向力的影响最为明显。(4)建立口环盖板侧间隙流整体计算模型,基于试验结果验证了求解间隙流动力特性系数方法的准确性;采用二阶摄动方程求解得到悬臂式多级离心泵的间隙流动力特性系数,并在设计工况下将间隙流动力特性系数以矩阵的形式耦合到模化之后的悬臂式多级离心泵转子系统中,分别对不考虑和考虑间隙流下的临界转速和不平衡响应进行了对比分析,发现间隙流的存在对转子具有一定的支撑效果,提高了转子系统的稳定性。(5)为了研究间隙流对转子振动性能的影响,设计并搭建完成了悬臂式多级离心泵振动及轴心轨迹测试实验台。基于振动试验台测得了不同流量工况下泵体振动和转子系统的轴心轨迹。研究发现,悬臂式转子系统工作时存在不平衡量,且在大流量点转子系统较为稳定,在小流量点出现不对中的现象,间隙流动影响明显。该试验结论为下一步悬臂式多级离心泵优化设计提供一定的参考。
[Abstract]:The compact structure of cantilever type multistage centrifugal pump, widely used in the military field, demanding more of the civilian space. But because of the impeller rotor and the guide vane is arranged on the side away from the bearing support, cantilever multi-stage pump rotor system under unbalanced load is very easy to produce the radial deflection, unstable vortex the gap exists in the phenomenon. However, flat side and ring the leakage flow is one of the important source of excitation therefore, leakage flow for cantilever type multistage pump can not be ignored, it is necessary to study the flow condition and the dynamic characteristics of space. This paper takes M220 type multistage centrifugal pump as the research object, flow in the gap clearance, dynamic characteristics and effect of clearance flow on the stability of the rotor are studied, and on this basis to carry out a series of the clearance flow on the rotor performance impact test Experimental research in this paper. The main work and research results are: (1) CFX 14.5 in multistage centrifugal pump with leakage of whole flow field based on the steady calculation, simulation results agree well with the experimental results, verified the accuracy of numerical simulation. Analysis of the impact of clearance flow under the condition of the pump body of the mainstream field. The distribution of static pressure on the mainstream flow under small flow rate condition the influence of gap, velocity distribution and turbulent kinetic energy distribution is most obvious. (2) M220 leakage model to construct 4 space channel based on the pressure fluctuation in a way to find the gap flow correlation weight distribution and gap structure. The study found that the ring and level the gap between the existence of an increase of around the frequency of the pump chamber, before the pump pressure pulsation with a mouth ring along the gap flow from the outside diameter to the inner diameter increased after the pump pressure pulsation level of the gap between the opposite. (3) based on the CFD method On the external characteristics, cantilever type multistage centrifugal pump impeller at different axial displacement pump energy characteristics, shroud clearance flow, pressure pulsation of axial force and radial force gap were studied. By contrast, found that before the pump cavity gap and radial force characteristics changes of foreign influence, influence of pump cavity gap the axial force is most obvious. (4) a ring cover flow calculation model of overall clearance, test results verify the accuracy of solving the gap flow dynamic coefficients based on the method of using space; two order perturbation equations are solved for cantilever multi stage centrifugal pump flow dynamic characteristics and operating conditions in the design of the clearance flow the dynamic coefficients to form coupled to the modular matrix of the cantilever type multistage centrifugal pump rotor system, respectively with and without clearance flow under the critical speed and unbalance response in the Analysis, found the clearance flow has a certain effect on the rotor support, improve the stability of the rotor system. (5) in order to study the gap flow effects on the performance of rotor vibration, design and build a test bench cantilever multi-stage centrifugal pump vibration and orbit orbit measurement test. With different flow conditions of pump body vibration and vibration of rotor system based on test bench. The study found that the cantilever rotor system when unbalance, and more stable in the large flow rotor system, not the phenomenon appears in the small flow rate, clearance flow significantly affected. The test results for the next step of cantilever type multistage centrifugal pump optimization design to provide certain reference.

【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH311

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