中压受热通道密度波不稳定性研究

摘要

采用RELAP5/Mod3.4软件对某一中压受热通道进行密度波不稳定性分析,探讨了节点个数对流动不稳定性的影响,分析了入口单相水的质量流量、入口长度和上升长度、入口和出口局部阻力系数、入口过冷度对受热通道密度波不稳定性的影响,并通过引入过冷数和相变数得到了受热通道的稳定边界.结果表明:在使用RELAP5程序进行不稳定性分析前,有必要进行节点划分敏感性分析；当增大受热通道入口单相水质量流量或增大入口局部阻力系数时,受热通道的流动稳定性增强；当增大受热通道入口长度或上升长度和出口局部阻力系数时,受热通道的流动稳定性降低；过冷数和相变数可用于描述受热通道稳定性边界.%The density wave instability in a medium-pressure heated channel was studied using RELAP5/Mod3.4 software,while the sensitivity of the number of nodes investigated based on the prediction results.The influence of following factors on the density wave instability was analyzed,such as the inlet mass flow of single phase water,inlet/outlet length,inlet/outlet local resistance factor and the inlet degree of supercooling,etc.,after which the boundary of flow stability was determined based on the supercooling number and phase change number.Results show that it is necessary to perform a node sensitivity analysis before studying the density wave instability using RELAP5 software.The flow stability in heated channel increases with rising inlet mass flow of single phase water,rising inlet local resistance factor,reducing inlet/outlet length and reducing outlet local resistance factor.The boundary of flow stability can be described using both the supercooling number and phase change number.