钠冷快堆分析程序ATHAS-LMR的子通道模型

以子通道模型和绕丝分布式阻力模型为基础,研发了液态金属快中子增殖堆热工水力子通道分析程序ATHAS-LMR,以对液态金属快中子增殖堆燃料组件中的热工水力现象进行分析。与国外知名实验和类似子通道分析程序比较,结果表明:ATHAS-LMR与实验结果及其他子通道分析程序的结果相近,能够完成包括堵流工况的各种工况下液态金属快中子增殖堆组件的热工水力性能分析。

精细化子通道棒弯曲模型的验证与分析

为提高子通道程序在棒弯曲情况下对子通道局部参数变化的预测能力,本研究在对子通道进行精细划分的基础上,建立了精细化子通道棒弯曲模型对棒弯曲进行分析,并利用计算流体动力学(CFD)来验证精细化子通道棒弯曲模型对子通道轴流和横流的预测能力。通过CFD对模型进行验证,分析了棒弯曲段轴流和横流的变化趋势。结果表明,程序ATHAS和CFD对轴流和横流的变化趋势预测基本一致,精细化子通道棒弯曲模型可以较好地预测棒弯曲引起的轴流和横流的变化趋势。因此,精细化子通道棒弯曲模型可以预测弯曲棒对局部流场的影响,为临界热流密度的预测提供了基础。

Calculation mode of side friction for large open caisson

To overcome the problems in design methodologies and construction control measures for the large open caisson, systematic research was conducted on the side friction calculation mode of the large open caisson. Based on the field monitoring data of lateral soil pressure on the side wall of the open caisson for the southern anchorage of the Maanshan Yangtze River Highway Bridge, the statistical result of the side friction under different buried depths of the cutting edge of the open caisson was back-analyzed; and the side friction distribution of the large open caisson was underlined. The analysis results indicate that when the buried depth of the cutting edge is smaller than a certain depth H0, the side friction linearly increases with the increase in the buffed depth. However, as the buffed depth of the cutting edge is larger than H0, the side friction shows a distribution with small at both ends and large in the middle. The top of the distribution can be regarded as a linear curve, while the bottom as a hyperbolic curve. As the buffed depth of cutting edge increases continuously, the peak value of the side friction linearly increases and the location of the peak value gradually moves down. Based on the aforementioned conclusions, a revised calculation mode of the large open caisson is presented. Then, the calculated results are compared with the field monitoring data, which verifies the feasibility of the proposed revised calculation mode.

定位格架模型对子通道分析程序的影响研究

子通道分析程序只能进行简单的定位格架模型分析,对格架的考虑仅以形阻系数表示,仅能反映轴向的平均阻力效应,难以反映格架上不同角度和排布的交混翼对流场及温度场的影响,不能准确反映格架中的交混翼对局部参数的影响。本文通过选用适当的阻力经验关系式,引入交混翼几何尺寸及交混翼角度,将交混翼对流体产生的力定量地表示出来,添加至动量方程中,建立了新的交混翼分布式阻力模型,并将其耦合到ATHAS子通道分析程序中。程序经过对5×5棒束组件在不同结构下的计算,对比有交混翼和无交混翼子通道内的流场,研究不同形状、角度、排列方式的交混翼产生的效应。

CSR1000带肋子通道程序验证及分析

超临界水冷堆燃料组件多采用绕肋进行自定位,绕肋对于组件热工水力特性的影响较为复杂。在超临界子通道程序ATHAS的基础上改进绕肋处理模块,并基于计算流体力学(CFD)工具对绕肋模型进行验证。改进后的子通道分析程序整体上能够反映出不同通道的变化趋势,对绕肋的几何参数变化也能做出较为合理的响应,证明绕肋模型正确;但在部分通道的预测上仍需要进一步改进。