棒束中高含气量空泡份额计算模型适用性的研究

Applicability of Void Fraction Models in Rod Bundle at High Quality Conditions

在子通道分析程序中,空泡份额计算模型对两相流的分析预测结果有显著影响。在较高含气率条件下,空泡份额计算模型在子通道分析程序COBRA中的适用性并没有经过充分的验证。本文用COBRA程序中自带的空泡份额计算模型与选自文献的4个空泡份额模型,对4×4棒束的气-液两相流进行子通道分析。结合实验数据,选取相对焓升和相对质量流速比,对预测结果进行分析评估。结果表明,在本文的计算范围内,Dix模型和滑速比S=1.5时的滑速比模型的预测结果最优。

Void fraction model is of great importance to the sub-channel analysis. However, the applicability of the void fraction models in the sub-channel codes COBRA under high void fraction conditions is not sufficiently validated. Based on a literature review, four void fraction models are selected and applied to the COBRA code to calculate the thermal hydraulic parameters in rod bundles. Comparing to the experimental data obtained in a 4×4 rod bundle using water as coolant, the selected void fraction models are assessed by using relative enthalpy rise and relative mass flux in various sub-channels. It was found that the calculated sub-channel parameters with the Dix model and the slip model （with a slip ratio of 1.5） give the best agreement with the experiment data.