摘要
由于小支管振动超标的敏感管问题是困扰所有核电站的难题。国内外投入了大量的人力和物力来解决敏感管问题。分析判断振动原因是解决敏感管问题的首要因素。本文用综合的技术手段对某核电厂安注系统低压安注泵小流量管线中的敏感管振动原因进行了分析研究。通过在管线上布置加速度计进行现场振动实测获得了管线的振动分布,通过振动加速度的时程的RMS值分布获得了节流孔板后方是振动最大的位置,通过对节流孔板后方的加速度进行频谱分析初步判断为节流孔板过分节流导致通过孔板的流体汽化而出现了汽蚀现象。通过对节流孔板的理论分析获得了节流孔板前后的压差并与阻塞压差进行比较进一步验证了节流孔板的过分节流现象。最后用CFD进行了三维流场分析获得了整个管线的详细流场分布,并得到了经过节流孔板后出现了流场中低于流体饱和蒸汽压的区域,该区域是流体汽化区。通过综合的手段最后确定导致该小流量管线振动高的主要原因是节流孔板的汽蚀。本文所用的方法对其他具有类似的振动现象的振动原因分析具有借鉴的意义。
The sensitive tube problems of small flow pipeline which the vibration exceed the require perplex all nuclear power plants.Domestic and foreign invested a lot of manpower and material resources to solve the problem of sensitive tube.To obtain the vibration reason is the primary factor to solve the sensitive tube problem.In this paper,a comprehensive technical means is adopted to study the vibration reason of small flow pipeline of low pressure injection pump of safety injection system of nuclear power station.To obtain the distribution of the vibration of the pipeline the accelerometers are installed on the pipeline for field vibration test.Through the time history analysis of the RMS of vibration acceleration value the position behind the throttling orifice plate is the maximum vibration resource.Based on the acceleration behind the throttling orifice plate spectrum analysis the preliminary judgment for throttling orifice throttling too much lead to vaporization flow through orifice and appear the phenomenon of cavitation.The pressure drop the through the throttling orifice plate is obtained by the theory analysis and verify the phenomenon of excessive throttling orifice plate by comparing with blocking pressure drop.Finally the three-dimensional flow field analysis is adopted to obtain the detailed flow field distribution of the entire pipeline by computer fluid dynamic(CFD),and obtained the zone below the fluid saturation vapour pressure behind the throttling orifice plate which is the fluid evaporation area.By the comprehensive means the main vibration cause the sensitive tube on the small high flow pipeline vibration is cavitation of the throttling orifice plate of cavitation.The method Used in this article can be used to other similar vibration phenomenon.
作者
席志德
秦强
马建中
张士朋
XI Zhi-de;QIN Qiang;MA Jian-zhong;ZHANG Shi-peng(Mechanical Laboratory for Reactor Structure of Nuclear Power Institute of China,Chengdu,Sichuan Prov.610041,China;SuZhou Nuclear Power Research Institute,Shenzhen,Guangdong Prov.518124,China;DAYA Bay Nuclear Power Station,Shenzhen,Guangdong Prov.518124,China)
出处
《核科学与工程》
CAS
CSCD
北大核心
2018年第2期273-277,共5页
Nuclear Science and Engineering
