Experimental Study on Edge Blockage Accidents and Central Blockage Accidents in a Rectangular Channel
-
摘要: 为获得矩形通道堵塞事故下流场的演化规律,本文利用粒子图像测速(PIV)技术,针对间隙为3 mm竖直窄矩形通道堵塞事故开展全流场可视化实验研究,对比分析70%阻塞率下边缘堵塞和中心堵塞工况流场结构的差异性。研究发现:边缘堵塞的流场结构比中心堵塞的流场结构更复杂,边缘堵塞工况会因流道阻塞形成更大的回流区,同时在高雷诺数(Re)下会形成壁面分离涡;边缘堵塞更不利于流体热量的导出,其回流区内漩涡的涡量更小,漩涡流动性更差、运动频率更复杂;同时边缘堵塞和中心堵塞内漩涡结构随Re变化趋势也完全相反。
-
关键词:
- 粒子图像测速(PIV) /
- 功率谱密度(PSD) /
- 阻塞事故 /
- 板状燃料元件 /
- 矩形通道
Abstract: To obtain the evolution law of the flow field under the rectangular channel blockage accident, the particle image velocimetry (PIV) technology is adopted to carry out a full-flow-field visual experimental study on the vertical narrow rectangular channel blockage accident with a gap of 3 mm to compare and analyze the difference of the flow field structure under the condition of edge blockage and central blockage at 70% blockage rate. It is found that the flow field structure of edge blockage is more complex than that of central blockage, the edge blockage condition will form a larger backflow area due to channel blockage, and a wall separation vortex will be formed at high Reynolds number (Re); the edge blockage is more unfavorable to the removal of fluid heat, and the vorticity of the vortex in the backflow area is smaller, the fluidity of the vortex is worse, and the motion frequency is more complex; At the same time, the variation trend of vortex structure in edge blockage and central blockage with Re is also completely opposite. -
-
[1] 董化平,樊文远,郭赟. 动网格技术在板状燃料组件流道阻塞 事故模拟中的应用[J]. 海军工程大学学报,2018, 30(1): 17-21. doi: 10.7495/j.issn.1009-3486.2018.01.004 [2] MA Z H, CHEN R H, TIAN M L, et al. Analysis of flow blockage accidents in rectangular fuel assembly based on CFD methodology[J]. Annals of Nuclear Energy, 2018, 112: 71-83. doi: 10.1016/j.anucene.2017.09.012 [3] LI J Q, CHEN X M, LI J C. Analysis on a flow blockage incident at a plate-type fuel reactor[J]. Atomic Energy Science and Technology, 2002, 36(1): 76-79. [4] LU Q, QIU S Z, SU G H. Flow blockage analysis of a channel in a typical material test reactor core[J]. Nuclear Engineering and Design, 2009, 239(1): 45-50. doi: 10.1016/j.nucengdes.2008.06.016 [5] SALAMA A. CFD analysis of fast loss of flow accident in typical MTR reactor undergoing partial and full blockage: the average channel scenario[J]. Progress in Nuclear Energy, 2012, 60: 1-13. doi: 10.1016/j.pnucene.2012.05.002 [6] SALAMA A, EL-MORSHEDY S E D. CFD analysis of flow blockage in MTR coolant channel under loss-of-flow transient: hot channel scenario[J]. Progress in Nuclear Energy, 2012, 55: 78-92. doi: 10.1016/j.pnucene.2011.11.005 [7] FAN W Y, PENG C H, CHEN Y L, et al. A new CFD modeling method for flow blockage accident investigations[J]. Nuclear Engineering and Design, 2016, 303: 31-41. doi: 10.1016/j.nucengdes.2016.04.006 [8] SON H M, YANG S H, PARK C, et al. Transient thermal–hydraulic analysis of complete single channel blockage accident of generic 10 MW research reactor[J]. Annals of Nuclear Energy, 2015, 75: 44-53. doi: 10.1016/j.anucene.2014.08.002 [9] DAVARI A, MIRVAKILI S M, ABEDI E. Three-dimensional analysis of flow blockage accident in Tehran MTR research reactor core using CFD[J]. Progress in Nuclear Energy, 2015, 85: 605-612. doi: 10.1016/j.pnucene.2015.08.008 [10] YUAN D D, DENG J, ZHANG X X, et al. Experimental investigation of turbulent flow under different Reynolds numbers and blockage ratios in a heated rectangular channel[J]. Annals of Nuclear Energy, 2021, 164: 108608. doi: 10.1016/j.anucene.2021.108608 [11] YUAN D D, DENG J, HAN R, et al. Experimental study on flow structures of central blockage accidents in a rectangular channel using PIV and POD[J]. Annals of Nuclear Energy, 2021, 153: 108037. doi: 10.1016/j.anucene.2020.108037 [12] 王畅. 周期力场作用下矩形通道内流动传热与特性研究[D]. 哈尔滨: 哈尔滨工程大学, 2013. [13] FAN W Y, PENG C H, GUO Y. CFD study on inlet flow blockage accidents in rectangular fuel assembly[J]. Nuclear Engineering and Design, 2015, 292: 177-186. doi: 10.1016/j.nucengdes.2015.06.016