In integral test facilities, some phenomena relevant in the separate effect test are usually neglected due to scaling limitations and design compromises. The typical heat transfer phenomenon in reactor core in large break loss of coolant accident (LBLOCA) scenario is analyzed with fractional scaling analysis (FSA) method in this work. A conservation form of cladding temperature is derived on the basis of energy conservation. Then the scaling criteria and their importance are evaluated. It is found that the similarities of the criteria for convection heat transfer and heat accumulation should be guaranteed since their priorities are high. The contribution of initial pressure and distribution of coolant inventory to cladding temperature in LBLOCA scenario is too slight. This work is encouraging and may shed a light on the coupling application of hierarchical two-tiered scaling (H2TS) and FSA method in engineering application.

中文翻译：

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大破口冷却剂损失事故包壳温度分数标度分析

在整体测试设施中，由于规模限制和设计妥协，一些与单独效应测试相关的现象通常被忽略。本文采用分数尺度分析（FSA）方法对大破口冷却剂损失事故（LBLOCA）场景下反应堆堆芯的典型传热现象进行了分析。在能量守恒的基础上导出了包层温度守恒形式。然后评估缩放标准及其重要性。研究发现，对流传热和蓄热准则的相似性应得到保证，因为它们的优先级较高。 LBLOCA 场景中初始压力和冷却剂库存分布对包壳温度的贡献太小。这项工作令人鼓舞，并可能为分层两层标度（H2TS）和 FSA 方法在工程应用中的耦合应用提供启示。