竖直窄缝通道内轴向功率阶跃分布下临界热流密度理论分析  

Theoretical Study on Critical Heat Flux in Vertical Narrow Tube with Axial Power Step

作　　者：刘叶[1] 赵大卫[1] 刘文兴[1] 昝元锋 

机构地区：[1]中国核动力研究设计院中核核反应堆热工水力技术重点实验室,成都610041

出　　处：《核动力工程》2016年第4期6-10,共5页Nuclear Power Engineering

基　　金：国家自然科学基金青年项目(11505177和51406189)

摘　　要：采用竖直窄缝通道内功率阶跃分布下的临界试验结果对非均匀加热临界预测模型进行验证。模型所预测临界触发位置、临界热流密度(CHF)及临界对应平均热流密度与试验结果的偏差均在合理范围内。采用该非均匀加热临界预测模型开展功率阶跃下CHF的数值计算,分析阶跃功率比、阶跃长度以及阶跃位置对沸腾临界的影响:随阶跃功率比的增大,CHF基本呈线性增大,但临界触发时的平均热流密度逐渐降低;阶跃长度的增大使得CHF逐渐减小,同时触发时的平均热流密度逐渐逼近均匀加热下的CHF值;随临界触发区域向流道上游迁移,临界触发位置将脱离功率阶跃区域的后端迁移至流道出口,此时的CHF值及临界触发时的平均热流密度值均趋近于均匀加热下的CHF值。In the present study, the critical heat flux（CHF） experiments in vertical narrow tube with power step are conducted to verify the CHF predictions by non-uniform heating CHF model. The boiling crisis position, CHF, qN,CHF, and average heat flux, qN,AVE, predicted by non-uniform heating CHF model, show a reasonable agreement with the CHF experimental results. The CHFs for different power steps are calculated using this non-uniform heating CHF model to analyze the effects of power step ratio, Rh, power step length, Lh, and the power step position on the boiling crisis： The qN,CHF approximately linearly increases with an increase of Rh. While the qN,AVE decreases with the increasing Rh. As Lh increases, qN,CHF decreases signific.antly and qN,AVE approaches to CHF under uniform heating condition, qU,CHF. When the position of the power step moves to the upstream, the boiling crisis position will depart from the end of power step. As boiling crisis is trigged at the outlet of tube, the qN,CHF and qN,AVE are both approximately equal to qU,CHF.

关 键 词：临界热流密度 功率阶跃 微液层蒸干模型 

分 类 号：TL33[核科学技术—核技术及应用]