核反应堆吊篮振动引发中子噪声的实验研究  

Experimental Study on Neutron Noise Induced by Core Barrel Vibration of Nuclear Reactor

作　　者：刘才学[1] 魏东[1] 房成春[1] 何绍群[1] 胡精华[1] 

机构地区：[1]中国核动力研究设计院,成都610041

出　　处：《核动力工程》2006年第1期25-29,共5页Nuclear Power Engineering

摘　　要：利用临界装置,开展了吊篮振动引发中子噪声实验研究。在反应堆稳定运行工况下,采取随机信号、窄带扫频和单频3种激励方式激励吊篮振动。在最大激励力下,吊篮最大振幅21μm,主要振幅在3～10μm。对中子噪声频谱分析显示,本底中子噪声信号频谱幅度随频率近似呈指数衰减。对临界装置的吊篮,振动引发的中子噪声频谱主要分布在数十Hz以上,容易分辨。研究中采用了高通数字滤波技术,改善了对特征频率的观察和识别。随机力激励吊篮,激发出了吊篮和围板的低、中频振动引发的中子噪声特征谱;窄带扫频激励吊篮,在20Hz～70Hz范围的扫频窄带内,中子噪声频谱主要出现70Hz以上的特征谱线,在70Hz～110Hz范围内,主要出现低于扫频窄带频率的特征谱线,在110～180Hz范围内,主要出现125Hz左右的特征谱线,从180～190Hz起的窄带扫频中,只能激励125Hz左右的特征谱线;30Hz～150Hz频率范围内单频激励吊篮,主要出现几个特征谱峰。由此鉴别出吊篮振动模态频率为76.2、125.0、181、215、239.7Hz。This paper deals with the experiment of neutron noise induced by the core barrel vibration of the critical installation. Three kinds of stimulation including random signal, narrow band sweep frequency signal and single frequency signal are adopted to stimulate the core barrel vibration. At biggest stimulation force, the biggest vibration amplitude is 21μm, generally in 3 to 10μm. The amplitude of the frequency spectrum of background noise presents an exponential reduction with the frequency, at 10Hz frequency, and the amplitude reduces 10 times or so. To this reactor, the frequency spectrum of the neutron noise induced by the core barrel vibration distributes mainly over tens Hz, and may be identified easily. A high-pass digital filter is adopted to improve the the observation and identification of the characteristic spectrum. The characteristic spectrum of neutron noise in the lower and middle frequency range is brought on by the core barrel vibration stimulated by random force. As stimulated by the narrow band sweep frequency force, the characteristic spectrum above 70Hz is brought on by the core barrel vibration stimulated by the sweep frequency range from 20 to 70Hz; the characteristic spectrum lower the band frequency is brought on by the core barrel vibration stimulated by the sweep frequency range from 70 to 110Hz; the characteristic spectrum of frequency peak at about 125Hz is brought on by the core barrel vibration stimulated by sweep frequency range from 110 to 180Hz. The characteristic spectrum including several frequency peaks is brought on by the core barrel vibration stimulated by single frequency range from 30 to 150Hz. The mode frequencies of the core barrel vibration in normal temperature water are 76.2, 125.0, 181, 215 and 239.7Hz.

关 键 词：吊篮 激振 振动 中子噪声 核反应堆 

分 类 号：TL351.1[核科学技术—核技术及应用]