液态金属在堆芯子通道内的湍流换热
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摘要
采用Speziale-Sarkar-Gatski(SSG)雷诺应力模型对液态金属在堆芯子通道内的流动、传热过程进行计算流体动力学(Computational Fluid Dynamics,CFD)模拟,研究雷诺数(Re)、分子普朗特数(Pr)、格拉晓夫数(Gr)、节径比(P/D)等无量纲参数对湍流换热的影响。比较无量纲对流换热系数(Nu)可以看出,CFD预测值与实验值及经验关系式符合得较好。对各种不同无量纲参数下的计算结果进行分析发现:在P/D和Re数相同条件下,三角形子通道的壁面温度分布比方形更均匀,换热情况更好;提高Re数,增大P/D,选用Pr数大的冷却剂,可有效改善温度和换热的周向分布不均情况;在Re数大于10 000的条件下,浮力对液态金属换热的影响可忽略不计。
Background: Liquid metal has been proposed as the coolant of the fourth generation nuclear reactor and the accelerator driven sub-critical system. Due to its low molecular Prandtl number(Pr), liquid metal differs from other coolants like water or gas in heat transfer. Purpose: This study aims to investigate the character of heat transfer of liquid metal inside the reactor core. Methods: Speziale-Sarkar-Gatski(SSG) Reynolds stress model was applied to the Computational Fluid Dynamics(CFD) prediction of liquid metal flow and heat transfer inside the sub-channels of the reactor core. Effect of different dimensionless parameters, e.g. Reynolds number(Re), Pr, Grashof number(Gr) and pitch-to-diameter ratio(P/D) on the turbulent heat transfer calculated results was investigated. Results: The dimensionless convective heat transfer coefficient(Nu), predicted by the CFD method, agrees well with the experimental data and the empirical relations. Conclusion: Based on the analysis of various dimensionless parameters, it is found that the heat exchange performs better in triangular fuel assembly sub-channels than that in square sub-channels, under the same condition of P/D and Re. The inhomogeneous circumferential distributions of temperature and heat transfer can be effectively improved by increasing Re and P/D or choosing coolants with large Pr. When Re is larger than 10 000, the buoyancy effect on liquid metal heat transfer could be ignored.
Background: Liquid metal has been proposed as the coolant of the fourth generation nuclear reactor and the accelerator driven sub-critical system. Due to its low molecular Prandtl number(Pr), liquid metal differs from other coolants like water or gas in heat transfer. Purpose: This study aims to investigate the character of heat transfer of liquid metal inside the reactor core. Methods: Speziale-Sarkar-Gatski(SSG) Reynolds stress model was applied to the Computational Fluid Dynamics(CFD) prediction of liquid metal flow and heat transfer inside the sub-channels of the reactor core. Effect of different dimensionless parameters, e.g. Reynolds number(Re), Pr, Grashof number(Gr) and pitch-to-diameter ratio(P/D) on the turbulent heat transfer calculated results was investigated. Results: The dimensionless convective heat transfer coefficient(Nu), predicted by the CFD method, agrees well with the experimental data and the empirical relations. Conclusion: Based on the analysis of various dimensionless parameters, it is found that the heat exchange performs better in triangular fuel assembly sub-channels than that in square sub-channels, under the same condition of P/D and Re. The inhomogeneous circumferential distributions of temperature and heat transfer can be effectively improved by increasing Re and P/D or choosing coolants with large Pr. When Re is larger than 10 000, the buoyancy effect on liquid metal heat transfer could be ignored.
引文
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10 王美,巫英伟,田文喜,等.液态金属钠在环管中湍流传热特性研究[J].核动力工程,2013,34(4):53–57WANG Mei,WU Yingwei,TIAN Wenxi,et al.Turbulent heat transfer characteristics of liquid sodium flow in an annular tube[J].Nuclear Power Engineering,2013,34(4):53 –57
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12 Cheng X,Tak N I.CFD analysis of thermal-hydraulic behavior of heavy liquid metals in sub-channels[J].Nuclear Engineering and Design,2006,236(18):1874–1885.DOI:10.1016/j.nucengdes.2006.02.001
13 Cheng X,Tak N I.Investigation on turbulent heat transfer to lead-bismuth eutectic flows in circular tubes for nuclear applications[J].Nuclear Engineering and Design,2006,236(4):385–393.DOI:10.1016/j.nucengdes.2006.09.006
14 Tóth S,Aszódi A.CFD analysis of flow field in a triangular rod bundle[J].Nuclear Engineering and Design,2010,240(2):352–363.DOI:10.1016/j.nucengdes.2010.08.020
15 Yu Y Q,Yan B H,Cheng X,et al.Simulation of turbulent flow inside different subchannels in tight lattice bundle[J].Annals of Nuclear Energy,2011,38(11):2363–2373.DOI:10 .1016/j.anucene.2011.07.018
16 Horvath A,Dressel B.Numerical simulations of square arrayed rod bundles[J].Nuclear Engineering and Design,2012,247:168–182.DOI:10.1016/j.nucengdes.2012.03.004
17 Gou J,Shang Z,Ishiwarari Y,et al.CFD analysis of heat transfer in subchannels of a super fast reactor[J].Nuclear Engineering and Design,2010,240(7):1819–1829.DOI:10 .1016/j.nucengdes.2010.03.013
18 Chandra L,Roelofs F.CFD analyses of liquid metal flow in sub-channels for Gen IV reactors[J].Nuclear Engineering and Design,2011,241(11):4391–4403.DOI:10 .1016/j.nucengdes.2011.01.023
19 Pacio J,Daubner M,Fellmoser F,et al.Heavy-liquid metal heat transfer experiment in a 19-rod bundle with grid spacers[J].Nuclear Engineering and Design,2014,273 :33–46.DOI:10.1016/j.nucengdes.2014.02.020
20 徐銤.钠冷快堆的安全性[J].自然杂志,2013,35(2):79 –84.DOI:10.3969/j.issn.0253-9608.2013.02.001XU Mi.Safety on sodium cooled fast reactor[J].Chinese Journal of Nature,2013,35(2):79–84.DOI:10.3969/j.issn.0253-9608.2013.02.001
21 OECD/NEA Nuclear Science Committee.Handbook on lead-bismuth eutectic alloy and lead properties,materials compatibility,thermal-hydraulics and technologies[R].Issy-les-Moulineaux,France:OECD Nuclear Energy Agency,2007
2 詹文龙,徐瑚珊.未来先进核裂变能–ADS嬗变系统[J].中国科学院院刊,2012,27(3):375–381.DOI:10.3969/j.issn.1000-3045.2012.03.017ZHAN Wenlong,XU Hushan.Advanced fission energy program-ADS transmutation system[J].Bulletin of the Chinese Academy of Sciences,2012,27(3):375–381.DOI:10.3969/j.issn.1000-3045.2012.03.017
3 Maresca M W,Dwyer O E.Heat transfer to mercury flowing in-line through a bundle of circular rods[J].Journal of Heat Transfer,1964,86(2):180–186.DOI:10 .1115/1.3687091
4 Mikityuk K.Heat transfer to liquid metal:review of data and correlations for tube bundles[J].Nuclear Engineering and Design,2009,239(4):680–687.DOI:10.1016/j.nucengdes.2009.12.014
5 石双凯,张振灿,张永积,等.液态金属钠在圆管和套管内的传热实验研究[J].工程热物理学报,1981,2(2):173 –180SHI Shuangkai,ZHANG Zhencan,ZHANG Yongji,et al.Experimental study of heat transfer to liquid metal sodium flowing in circular tube and annuli[J].Journal of Engineering Thermophysics,1981,2(2):173–180
6 张贵勤,向明忠,周学智.液态金属钠在环管热进口段的紊流换热实验研究[J].化工学报,1990,51(3):346 –352ZHANG Guiqin,XIANG Mingzhong,ZHOU Xuezhi.Exerimental investigation of turbulent heat transfer to liquid sodium in the thermal entrance region of an annulus[J].Journal of Chemical Industry and Engineering,1990,51(3):346–352
7 张贵勤,单建强,肖泽军,等.高温低Pe数与低温高Pe数液钠在环管中的换热研究[J].西安交通大学学报,1995,29(6):76–81ZHANG Guiqin,SHAN Jianqiang,XIAO Zejun,et al.Study of heat transfer to liquid sodium with high temperature and low Pe number and with low temperature and high Pe number in an annulus[J].Journal of Xi'an Jiaotong University,1995,29(6):76–81
8 朱志强,黄群英,章毛连,等.中国DRAGON系列液态金属锂铅回路及实验研究[C].第三届反应堆物理与核材料学术研讨会,北京,2007ZHU Zhiqiang,HUANG Qunying,ZHANG Maolian,et al.Chinese DRAGON series liquid metal Li Pb loop and experimental study[C].The 3rd Reactor Physics and Nuclear Materials Symposium,Beijing,2007
9 张贵勤,向明忠,单建强.液态金属在环管进口段的传热以及轴向导热的影响[J].化工学报,1994,45(5):560 –566ZHANG Guiqin,XIANG Mingzhong,SHAN Jianqiang.Heat transfer to liquid metal in thermal entrance region and the effect of axial heat conduction[J].Journal of Chemical Industry and Engineering,1994,45(5):560 –566
10 王美,巫英伟,田文喜,等.液态金属钠在环管中湍流传热特性研究[J].核动力工程,2013,34(4):53–57WANG Mei,WU Yingwei,TIAN Wenxi,et al.Turbulent heat transfer characteristics of liquid sodium flow in an annular tube[J].Nuclear Power Engineering,2013,34(4):53 –57
11 马在勇,仇子铖,王美,等.液态金属棒束传热的理论分析[J].原子能科学技术,2011,45(12):1478–1483MA Zaiyong,QIU Zicheng,WANG Mei,et al.Theoretical analysis of heat transfer for liquid metal through tube bundles[J].Atomic Energy Science and Technology,2011,45(12):1478–1483
12 Cheng X,Tak N I.CFD analysis of thermal-hydraulic behavior of heavy liquid metals in sub-channels[J].Nuclear Engineering and Design,2006,236(18):1874–1885.DOI:10.1016/j.nucengdes.2006.02.001
13 Cheng X,Tak N I.Investigation on turbulent heat transfer to lead-bismuth eutectic flows in circular tubes for nuclear applications[J].Nuclear Engineering and Design,2006,236(4):385–393.DOI:10.1016/j.nucengdes.2006.09.006
14 Tóth S,Aszódi A.CFD analysis of flow field in a triangular rod bundle[J].Nuclear Engineering and Design,2010,240(2):352–363.DOI:10.1016/j.nucengdes.2010.08.020
15 Yu Y Q,Yan B H,Cheng X,et al.Simulation of turbulent flow inside different subchannels in tight lattice bundle[J].Annals of Nuclear Energy,2011,38(11):2363–2373.DOI:10 .1016/j.anucene.2011.07.018
16 Horvath A,Dressel B.Numerical simulations of square arrayed rod bundles[J].Nuclear Engineering and Design,2012,247:168–182.DOI:10.1016/j.nucengdes.2012.03.004
17 Gou J,Shang Z,Ishiwarari Y,et al.CFD analysis of heat transfer in subchannels of a super fast reactor[J].Nuclear Engineering and Design,2010,240(7):1819–1829.DOI:10 .1016/j.nucengdes.2010.03.013
18 Chandra L,Roelofs F.CFD analyses of liquid metal flow in sub-channels for Gen IV reactors[J].Nuclear Engineering and Design,2011,241(11):4391–4403.DOI:10 .1016/j.nucengdes.2011.01.023
19 Pacio J,Daubner M,Fellmoser F,et al.Heavy-liquid metal heat transfer experiment in a 19-rod bundle with grid spacers[J].Nuclear Engineering and Design,2014,273 :33–46.DOI:10.1016/j.nucengdes.2014.02.020
20 徐銤.钠冷快堆的安全性[J].自然杂志,2013,35(2):79 –84.DOI:10.3969/j.issn.0253-9608.2013.02.001XU Mi.Safety on sodium cooled fast reactor[J].Chinese Journal of Nature,2013,35(2):79–84.DOI:10.3969/j.issn.0253-9608.2013.02.001
21 OECD/NEA Nuclear Science Committee.Handbook on lead-bismuth eutectic alloy and lead properties,materials compatibility,thermal-hydraulics and technologies[R].Issy-les-Moulineaux,France:OECD Nuclear Energy Agency,2007