摘要
利用RELAP5程序建立压力容器外部冷却(ERVC)系统模型,在水淹平衡条件下分析不同的安全壳内压力、冷却水过冷度、加热功率和水淹水位对系统两相自然流动能力的影响,找到各工况下的临界过冷度和不稳定性边界。结果表明:AP1000的ERVC系统设计具有很大裕量,仅依靠自然循环就可通过下封头对熔池进行有效冷却;安全壳内压力越高、冷却水过冷度越低、加热功率越大、水淹水位越高,两相自然循环流量越高。但当加热功率水平较低时,压力对临界过冷度影响不大;冷却水过冷度低于临界值时,会发生剧烈的倒流和流量震荡现象;当水淹水位低于5.5m时,不能建立稳定的两相自然循环流动。
A simulation model by utilizing RELAP5 was established for the external reactor vessel cooling（ERVC） system to investigate the effects of various thermal-hydraulic parameters such as containment pressure,subcooling,heating power and flooding water levels under the condition of cavity flooding balance on two-phase natural circulation flow capability of the system.The critical subcooling and instability boundary were found at given conditions.The results show that the thermal margin of ERVC system for AP1000 design is so large that the corium could be cooled down through lower head wall only by natural circulation.Flow rate of natural circulation increases as the containment pressure increases,the cavity water subcooling decreases,the heating power increases,and the flooding water level increases.Besides,pressure is not sensitive to critical subcooling when the heating power is low enough.When the subcooling is below the critical value,intensive flow oscillation and back flow occur,and the steady flow can not be established when the cavity water level is below 5.5 m.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2013年第7期1133-1140,共8页
Atomic Energy Science and Technology
