Abstract Accurate prediction of rod-bundle critical heat flux (CHF) is a main challenge in thermal-hydraulic design and safety assessment of Pressurized Water Reactor (PWR). The most widely applied approach is empirical correlation developed based on rod-bundle experiments carefully tested with geometry and power distribution representative to PWR working conditions. The standard procedure is to correlate the experimentally obtained CHF values as empirical functions of local thermal-hydraulic conditions obtained with subchannel analysis. However, up-to-date empirical correlations developed according to this manner are in general quite complicated with a number of dimensional coefficients and correction factors with less or non-physical meanings. In this study, stepwise regression method was used to develop a novel, dimensionless rod-bundle CHF correlation covering typical PWR working conditions. First, various dimensionless parameters affecting CHF were selected as candidate independent variables. With stepwise regression, the form and coefficients of the proposed CHF correlation were dynamically optimized and determined.

中文翻译：

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基于逐步回归方法的无量纲棒束 CHF 相关性的发展，第 I 部分：用均匀轴向热通量分布获得的 CHF 数据确定基本形式

摘要 棒束临界热通量（CHF）的准确预测是压水堆（PWR）热工水力设计和安全评估的主要挑战。应用最广泛的方法是基于棒束实验开发的经验相关性，这些实验用代表 PWR 工作条件的几何形状和功率分布进行了仔细测试。标准程序是将实验获得的 CHF 值关联为通过子通道分析获得的局部热工水力条件的经验函数。然而，根据这种方式开发的最新经验相关性通常非常复杂，具有许多具有较少或非物理意义的维度系数和校正因子。在这项研究中，逐步回归方法被用来开发一个新的，覆盖典型压水堆工作条件的无量纲棒束 CHF 相关。首先，选择影响 CHF 的各种无量纲参数作为候选自变量。通过逐步回归，动态优化和确定所提出的 CHF 相关性的形式和系数。