海洋条件下压水堆单相自然循环无量纲分析

Dimensionless Analysis of Single-Phase Natural Circulation Characteristics for PWR under Ocean Condition

针对单相单环路自然循环系统,采用Boussinesq近似建立无量纲分析方程,通过对单相动量及能量守恒关系的推导,得到不同外界条件下自然循环流量的影响参数。分析讨论倾斜、起伏与摇摆因素对自然循环流量的影响,并给出单相自然循环运行流量约束的保持条件。研究表明,倾斜时单相自然循环流量随倾斜角度的增加而减少;起伏运动时如果加速度与重力加速度的比值较小,对自然循环的影响可忽略;在不同摇摆条件下,如果引起自然循环流量的振幅相同,则其最大摇摆角加速度必然相同;单相自然循环运行的流量约束数值可由热源过冷度条件获得。

The dimensionless equation for a single-phase natural circulation loop has been established with the Boussinesq approximation. Through the deduction of single-phase momentum and energy equations, influencing parameter of natural circulation flow in different outside conditions has been obtained. The effect of heeling, heaving and rolling on flow variation of natural circulation has been discussed and the conservation criteria of single-phase natural circulation flow constraint have been given. This study showed that the single-phase natural circulation flow rate decreased as the heeling angle increasing. The heaving impact on the natural circulation flow rate is small as the heaving acceleration is much smaller than the gravity acceleration. In different rolling conditions, the maximum rolling angular acceleration are the same for identical flow rate oscillating amplitude. The constraint criteria of single-phase natural circulation flow can be obtained through the subcooling of heat source.