Abstract The accurate prediction of rod bundle critical heat flux (CHF) is an important task for thermal-hydraulic design of pressurized water reactor (PWR) core. Under normal and transient conditions of PWR, based on the two-phase flow pattern, there are different CHF regimes. In order to correctly distinguish the CHF regimes in rod bundle, it is necessary to analytical investigate rod bundle CHF-regime criterion. In this study, a general dimensionless rod bundle CHF correlation is presented based on dimensional analysis method. The real vapor quality, Katto number and boiling length are introduced to establish the basic form of the dimensionless CHF correlation. According to the deep analysis of the distribution trend of typical CHF experimental data and the CHF characteristics of different CHF regimes, the CHF in rod bundle are separated into DO, DNB and HP-DNB regimes. Concise dimensionless CHF correlations corresponding to each regime are developed, and the dimensionless equations between the boundaries of each regime are established. Also, a clearly defined map of characteristic regimes of CHF in rod bundle is determined. This study proposes a classification criterion for rod bundle for rod bundle CHF regimes, and it is very important for the upcoming development of rod bundle CHF mechanistic model.

中文翻译：

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基于无量纲群的棒丛CHF-制准则解析研究

摘要 棒束临界热通量（CHF）的准确预测是压水堆（PWR）堆芯热工水力设计的一项重要任务。在压水堆的正常和瞬态条件下，基于两相流型，存在不同的 CHF 状态。为了正确区分棒丛中的CHF状态，有必要对棒丛CHF-状态准则进行解析研究。在本研究中，基于量纲分析方法提出了一般无量纲棒束 CHF 相关性。引入真实的蒸汽质量、Katto 数和沸腾长度来建立无量纲 CHF 相关性的基本形式。根据对典型CHF实验数据分布趋势和不同CHF制度的CHF特征的深入分析，棒束中的 CHF 分为 DO、DNB 和 HP-DNB 状态。建立了对应于每个状态的简明无量纲 CHF 相关性，并建立了每个状态边界之间的无量纲方程。此外，还确定了杆束中 CHF 特征状态的明确定义图。本研究提出了杆束CHF机制的杆束分类标准，对杆束CHF机理模型的后续发展具有重要意义。