非能动安全壳冷却系统膜状冷凝强化换热设计

Design on Film Condensation Heat Transfer Enhancement in PCCS

非能动安全壳冷却系统(PCCS)能在反应堆发生事故时将安全壳内部的热量及时导出,避免安全壳因超温、超压而失效。为强化换热,本文设想在安全壳内部安装阻隔带和液滴收集装置,通过降低层流区液膜厚度、扰动不可凝气体隔离层并充分利用湍流的换热强化作用,降低总的换热热阻,提高换热效率。以AP1000为例,依托GDLM模型对改进前后安全壳的换热情况进行分析,结果表明,通过安装阻隔带和液滴收集装置,能降低安全壳壁面的液膜厚度,提高壁面热流量,从而实现强化换热。

The passive containment coolant system（PCCS）will remove energy in containment during a nuclear reactor accident,preventing containment form losing efficacy because of high temperature and pressure.In this paper,to improve heat transfer efficiency,it was assumed that several barrier rings and a droplet collector were installed in the containment.By reducing the liquid film thickness,disturbing the non-condensable gas layer,and using the higher heat transfer efficiency in the turbulence flow,the total thermal resistance was reduced and the heating efficiency was improved.Taking AP1000 as an example,the heat transfer efficiencies in containment in two cases with and without the new facility were analyzed with the GDLM model.The results show that barrier rings and droplet collector could decrease film thickness,raise heat flow and enhance heat transfer efficiency.