简谐海洋条件下自然循环运行特性

Natural Circulation Operational Characteristics Under Ocean Condition

基于两相漂移流模型建立简谐海洋条件下核动力装置自然循环理论分析模型;采用两群三维时空中子动力学模型描述堆芯中子的物理行为及控制棒调节系统的响应;利用研制的程序对核动力装置在摇摆条件下的自然循环运行特性及强迫循环向自然循环转换的过渡过程进行研究。结果表明:摇摆周期越小,影响越大;摇摆振幅越大,影响越大;相同摇摆周期与摇摆振幅条件下,纵摇对自然循环运行影响大;纵摇时,参数波动周期与摇摆周期相符,横摇时,参数波动周期为摇摆周期的一半;海洋条件引起过大的堆芯自然循环流量波动可造成功率自动调节控制棒的频繁动作,无法平稳实现强迫循环向自然循环的转换。

Based on the drift flux model, the natural circulation theory analysis models of nuclear power plant （NPP） under ocean condition were established. The neutron physical activities and the responses of reactivity control systems were described by the two-group, 3-D space and time dependent neutron kinetic model. Using the code devel- oped, the natural circulation operating characteristics of NPP and the transition process from forced circulation to natural circulation under rolling condition were analyzed. The results show that the shorter the roiling period is, the more the influence is, and that the bigger the rolling amplitude is, the more the influence is. With the same rolling period and amplitude, the effect of pitching on natural circulation is greater than that of rolling. The fact is that the parameter oscillation period for pitching is the same as the pitching period, and half of the rolling period. In the ocean environment, excessive flow oscillation of the natural circulation may cause the control rods response so frequently that the transition can＇t be realized steadily.