“华龙一号”压力容器直接安注比例模化可视化试验研究

An Scale Modeling and Visualized Experimental Study of Direct Vessel Injection of HPR1000

压力容器直接注入(DVI)技术可降低安注系统容量的要求,同时优化支持系统的配置,可以在保证安全的前提下简化安注系统设计、提高电厂经济性。本试验以“华龙一号”采用DVI技术优化的安注系统为研究对象,在模化比例为1:5的可视化模拟体上采用有色试剂跟踪法,以空气代替蒸汽,观察大破口失水事故(大LOCA)再淹没阶段DVI安注旁流特性,以及不同DVI管嘴结构对安注旁流的影响。发现大LOCA再淹没阶段安注旁流主要体现为直接旁流,在不带导流管嘴的4个DVI安注口的安注系统设计中,大LOCA再淹没初期的安注旁流约为7%,再淹没后期约为4%;带导流管嘴的DVI安注,再淹没初期的安注旁流约为2%,导流管嘴可有效降低安注旁流份额。本研究为“华龙一号”安全系统持续优化创新提供了重要参考。

Direct vessel injection(DVI)technology can reduce the requirement of the capacity of reactor safety injection system(RSI),as well as the support systems.Thus,while ensuring safety,it can achieve the goal of simplifying the RSI design and improve the economy of nuclear power plant.Using the DVI of HPR1000 RSI as the research object in this experiment,the colored reagent tracking method was adopted on a visualized simulated facility with the scaling ratio of 1:5.The air was substitute for steam.The characteristics of safety injection bypass during the reflooding phase of the large break loss of coolant accident(LBLOCA)are observed.And the influences of the safety injection bypass of different DVI nozzle forms are studied.During the LBLOCA reflooding phase,the mainly safety injection bypass is the direct bypass.In the RSI design of four DVI without guiding nozzle,the ratio of direct bypass is 7%in the beginning of the LBLOCA reflooding phase,and the ratio of direct bypass is 4%in the ending of the LBLOCA reflooding phase.In the condition of four DVI with guiding nozzles,the ratio of direct bypass was 2%in the beginning of the LBLOCA reflooding phase.The DVI guiding nozzle effectively reduced the ratio of the direct bypass.These studies provide necessary guidance for the continuous optimization and innovation of the HL1000 safety systems.