【作者】 平仕良；

【导师】 王乐勤；

【作者基本信息】 浙江大学 ， 化工过程机械， 2012， 博士

【摘要】 随着旋转机械得到广泛应用并日益向高性能、大容量方向发展,这促使流体与旋转转子之间的流固耦合作用不断增加,从而这种耦合作用对转子系统的动力特性和稳定性产生影响。本文以大功率高压多级离心泵为研究对象,围绕影响泵转子系统动力系统性的流体激振与转子系统的耦合作用,重点对多级离心泵级间设置的环压密封力产生机理及其动特性进行理论分析和实验研究。通过对多级离心泵三维流场计算与模拟,对离心泵的性能进行预测,全面观察多级离心泵的内部流动情况,捕捉到重要的流动现象,并获得主要部件的速度、压力分布,为后续研究中分析流固耦合作用对临界转速的影响提供依据。建立基于Navier—Stokes方程的密封动力学模型。详细推导计算多级离心泵级间环压密封动特性系数的方法,并通过大量计算实例验证了上述模型及算法,并分析了众多密封参数对密封动力特性的影响。建立基于有限元方法的大功率多级离心泵转子动力学模型。首先建立转子轴系的有限元模型,介绍线性化的油膜力和密封力模型,给出完善的多级离心泵转子“湿”态动力学分析方法。建立大功率高压多级离心泵转子刚性设计的理论和方法。在国内首次建立多级转子“湿”效应实验台。对密封力作用下转子系统的振动特征进行试验研究,通过试验结果分析系统密封力对转子系统动力学特性的影响。最后将理论分析的结果与试验结果进行比较。本文的研究给出了级间密封对多级转子动特性影响的试验结果,初步建立了数值仿真方法体系,为大功率高压离心泵的研制和优化提供了理论基础,具有重要的理论意义和很强的实际应用价值。更多还原

【Abstract】 As rotating machinery are used widely and become large-capacity, the stabilization and dynamics of rotating rotor were influenced by the increasing in coupled interaction between the fluid and the rotor.In this paper, the high-power high-pressure multi-stage centrifugal pump is regarded as investigate object. The theoretical analysis and experimental research on the generation mechanism of the ring sealing force set between multi-stage centrifugal and characteristics of ring sealing are studied according as coupled interaction between the fluid and the rotor.Through three-dimensional flow field simulation of the multi-stage centrifugal pump the performance of centrifugal pump is predicted. Some important flow Phenomena are got. The velocity and pressure distributions within the impellers, guide vanes, et al. are analyzed so that the later calculation on the critical speed can be continued.Based on Navier-Stokes equations, the seal dynamic model is established. o. Detailed derivation calculate multi-stage centrifugal pump interstage ring pressure seal dynamic coefficients of the method, and large amount of computation is verified by the above model and algorithm, and a number the reaction of sealing parameters on dynamic characteristics of sealing are analyzed.Based on the finite element method of high-power multi-stage centrifugal pump rotor dynamics model is established. Firstly, the establishment of the rotor shaft of the finite element model, introduced linearized oil-film force and the sealing force model, given the multi-stage centrifugal pump rotor sound "wet" state kinetic analysis. And the rotor rigid design theory and methods of high-power high-pressure multistage centrifugal pump is established.In the country, a multi-stage rotor "wet" effect bench is established firstly. The sealing force on the vibration characteristics of the rotor system is studied. Through test results, analyzing the influence factor of sealing force to the rotor system dynamics characteristics. Finally, the results of theoretical analysis and experimental results were compared.In this paper, the study shows the influence of the inter-stage seal on the rotor dynamic characteristics of multi-stage through the test results. A numerical simulation methodology is initially established, which provides a theoretical basis for development and optimization of high-pressure centrifugal pump, and has important theoretical significance and practical value.更多还原