核主泵动静叶栅匹配规律及瞬态干涉效应研究

Nuclear main pump is the only high speed rotating equipment in nuclear island and the heart of the nuclear island. Its performance and reliable operation directly affect the plant capacity and security. Becaue the nuclear main pump in the third generation of nuclear power technology is the centrifugal impeller and the radial guide vane and annular casing coupling structure model,Make it difficult to on performance parameters in the traditional design method, fluid induced vibration and stability of both. This project is based on the numerical simulation, flow field visualization measurement as well as the combination of external characteristic experiment, through the impeller, guide blade and casing orthogonal experiment design method, revealing the nuclear main pump impeller and guide blade and the multiple parameter matching rules ，and relationship between the rules and the external characteristic rule. Through the flow field analysis and diagnosis technology to clarify the nuclear main pump impeller and guide blade action under the interference of the transient flow field structure and the resulting flow stability problems, the different working conditions of different blade geometry parameters matching rule of pressure pulsation, fluid induced vibration, the flow field in the cascade structure and the influence law of energy conversion characteristics can be obtained. And the different working conditions of different blade geometry parameters matching rule of pressure pulsation, fluid induced vibration, the flow field in the cascade structure and the influence law of energy conversion characteristics can be gotten. Meanwhile potential flow and transient interference effect on the influence law of the impeller and guide blade surface load in the cascade would be revealed. All of the research results will provide certain theoretical guidance with overloading the design, manufacture and operation of nuclear main pump.

核主泵是核岛中唯一高速旋转的设备,是核岛的心脏,其性能及稳定性直接影响核电站的发电能力和安全。由于第三代核电技术中的主泵采用离心叶轮和径向导叶及环形压水室耦合结构模式，导致传统设计方法对性能参数、流体诱导振动及流动稳定性很难兼顾。本项目基于数值模拟、流场可视化测量以及外特性试验相结合的方式，通过叶轮、导叶、压水室正交试验方法，分析叶栅内的尾流、势流效应及瞬态干涉效应对叶轮和导叶表面载荷的影响，获得核主泵叶轮、导叶及压水室的多参数匹配关系与外特性之间的内在联系规律。采用涡动力学方法分析核主泵叶轮与导叶动静干涉下的瞬态流场结构，以及由此引起的流动稳定性问题。揭示不同工况下不同叶栅几何参数匹配规律与压力脉动、流体诱导振动、叶栅内流场结构及能量转换特性之间的映射关系，为无过载、高效核主泵的设计提供一定的理论指导。

目前，我国在第三代核主泵等关键技术装备研究领域，还没有形成完整的自主知识产权和研制能力，已成为重大工程和关键装备国产化的瓶颈和制约因素。与国外先进核电装备相比，我国在高效节能、动态性能、运行可靠性和寿命等方面还存在明显的差距。本课题通过采用试验和数值计算方法研究了模型核主泵叶轮、导叶和压水室耦合匹配特性对核主泵性能和流动稳定性的影响；核主泵非定常能量转换规律与叶轮、导叶载荷系数分布规律之间的关系；以及不同工况各水力部件耦合匹配对流场内压力脉动和径向力的影响规律。.研究结果表明：导叶轴向安放位置对压水内流场结构影响较大，减小导叶与泵出水管轴线在叶轮旋转轴线方向的距离，可以有效改善泵壳内的流动状态。环形压水室的水力损失在总损失中所占比重较大，水力损失主要分布在以出口为起点按叶轮旋转方向的1/2球体区域。当叶轮与导叶叶片数匹配最佳时，压水室内水力损失最小，泵的效率最高。设计工况下动静转子间隙对模型泵的扬程和水力效率影响较大，间隙在d=8.5mm附近时模型泵的性能最优。只改变叶轮叶片数时，叶轮与泵扬程增加趋势变缓；只改变导叶叶片数时，叶轮扬程随着导叶叶片数的变化较复杂，但存在一个扬程峰值。叶轮叶片中间流线上的动压载荷随着流量的增加逐渐减小，叶片动压载荷占叶片总载荷的比重越低则叶轮效率越高，不同工况下叶轮叶片载荷存在最优变化梯度。在不同工况下环形压水室内流动呈现明显的非轴对称性，由于回流存在导致隔舌附近区域流动复杂，且非设计工况下回流量要明显大于设计工况下的回流量。叶轮和导叶内的流动状态对压水室静压分布影响较小，但对压水室内速度场分布影响较大，偏设计工况下导叶流道内流动的失稳是引起压水室流动紊乱的主要原因。随着导叶周向位置变化，作用在叶轮上的径向力随时间呈现一定周期性波动，叶轮径向力脉动值主要由叶频决定，脉动幅值均发生在叶频的整数倍处，且导叶周向位置对叶轮径向力脉动影响有最优值。.上述研究成果已应用于核主泵高效水力模型的开发，为完善核主泵的设计理论和应用提供了理论依据。