罗忠发 孙爱东

摘  要：离心泵内部及入口流场稳定性对泵组十分重要，非稳定流会引起泵组振动偏大，对应的从非稳定流影响方面进行泵组降振的研究与实践凸显了其重要性。本文从泵入口流体初始状态、泵吸入口形式、泵内流场、小流量工况、部件表面粗糙度、口环间隙等方面分析了非稳定流对泵组振动的影响，并提出现场可行的处理措施，最终降低了泵组振动，使设备安全可靠运行，并为以后其他泵组振动处理提供了实践经验。

关键词：核电站  泵  非稳定流  振动

中图分类号：P47                                 文献标识码：A                    文章编号：1674-098X（2021）02（a）-0049-06

Analysis and treatment of unsteady flow excitation of seawater auxiliary cooling pump in nuclear power station

LUO Zhongfa  SUN Aidong

（Taishan Nuclear Power Joint Venture Co.， Ltd.， Jiangmen， Guangdong Province， 529200 China）

Abstract： The stability of flow field inside and at the inlet of centrifugal pump is very important to the pump set. The unsteady flow will cause the vibration of the pump set to be too large. The research and practice of vibration reduction of the pump set from the influence of unsteady flow highlights its importance. This paper analyzes the influence of unsteady flow on the vibration of pump unit from the initial state of fluid at pump inlet， the form of pump suction port， the flow field in the pump， small flow condition， surface roughness of components， gap between port and ring， etc.， and puts forward feasible treatment measures on site， so as to reduce the vibration of pump unit and ensure the safe and reliable operation of the equipment， which provides practical experience for the vibration treatment of other pump units in the future.Flow field stability of inside and suction is very important to centrifugal pump， while unsteady flow could cause high vibration. So unsteady flow analysis shows it's importance in the study and practice of pump vibration reduce. The paper analysed the influences of unsteady flow to pump vibration through initial state of suction flow， suction structure， inside flow field， low flowrate condition， surface roughness and wear ring clearance， presented feasible measures on site to finally reduce the pump vibration， which provided the practical experences to solve other pump bibration problems.

Key Words： Nuclear power station;  Pump;  Unsteady flow;  Vibration

大型立式泵具有結构紧凑的特点，在核电站广泛应用。但相对卧式泵而言，立式泵高度较高，轴系较长，水平刚度较差，转子支撑稳定性较差，容易出现振动问题。引起泵振动的主要原因有轴系不对中、动不平衡、动静摩擦、轴承故障、基础刚度差、共振、汽蚀、非稳定流激振等。其中非稳流引起的泵组振动偏大在现场实际较少进行分析，容易被忽视，对应从非稳流激振方面进行降低振动的实践相对较少。

以某核电厂辅助冷却水系统（SEN）为例。SEN系统作为冷源，为常规岛闭式冷却水系统（SRI）、凝汽器真空系统（CVI）提供海水。SEN系统有两列泵组，每列由2x100%的辅助冷却水泵供水（正常运行时每列各一台投运，一台备用）。2020年3月，SEN系统一台辅助冷却水泵（1SEN1220PO）在定期测振时发现泵轴承室驱动端水平方向振动超报警值。现场通过调整入口隔板角度、调整电机支架平面度等方法降低了泵组振动，保证了设备运行可靠性。……