棒束子通道CHF机理模型开发及初步验证

目前棒束通道中临界热流密度的预测多基于实验关系式，受限于特定的适用范围，无法有效外推或外推后预测精度下降。为满足不同轻水堆中临界热流密度的预测要求，有必要开发适用于不同几何尺寸及热工边界的宽范围临界热流密度预测方式。本文以子通道分析方法为基础，考虑偏离泡核沸腾和干涸两类临界现象，通过耦合子通道分析程序与临界热流密度机理模型，实现对棒束通道中临界热流密度的计算。通过与临界热流密度实验数据的对比，初步证明了耦合程序对棒束通道中临界热流密度具有较好的预测精度。

Development and Preliminary Validation of CHF Mechanistic Model for Rod Bundles

At present, the prediction of the critical heat flux (CHF) in the rod bundles is mostly based on the experimental correlations, which is limited by the specific application range, and cannot be effectively extrapolated or the prediction accuracy is reduced. In order to meet the prediction requirements of CHF in different light water reactors, it is necessary to develop a wide range of CHF prediction methods for different geometries and thermal boundaries. Based on the sub-channel analysis method, the two types of critical phenomena were considered in the paper, which were departure from nucleate boiling (DNB) and dryout, and the CHF in the bundles through coupling sub channel analysis code and the CHF mechanistic model was calculated. By comparing with the experimental data of CHF, it is proved that the coupling code has better prediction accuracy for the CHF in the rod bundles.