Thermal-Hydraulic Investigation of LBE Cooled Wire-Wrapped Fuel Bundle Based on Entropy Generation Analysis
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摘要: 为了从设计和运行的角度对铅-铋冷却快堆燃料组件的热工水力特性进行分析，基于有限体积法对铅-铋冷却的19根带有绕丝结构的燃料棒束进行数值模拟。对于不同质量流量、热功率下燃料组件流动及传热特性展开分析。并通过熵产分析方法，对不同工况下冷却剂熵产特性及热力学不可逆性进行研究。结果表明：二次流以及熵产分布在轴向上均呈现出周期性变化；入口速度是影响二次流以及熵产分布的主要因素；在保证结构安全的前提下，适当增加冷却剂流速有利于提高冷却剂的热经济性能。Abstract: In order to analyze the thermal hydraulic characteristics of LBE cooled fast reactor fuel assemblies from the point of view of design and operation, based on the finite volume method, 19 LBE cooled fuel rod bundles with wire-wrapped structures are numerically simulated. The flow and heat transfer characteristics of fuel assemblies under different mass flow rates and thermal power are analyzed. The entropy generation characteristics and thermodynamic irreversibility of coolant under different working conditions are studied by entropy generation analysis method. The results show that the secondary flow and the distribution of entropy generation show periodic changes in the axial direction; the inlet velocity is the main factor affecting the secondary flow and entropy generation distribution; On the premise of ensuring structural safety, increasing coolant flow rate appropriately is conducive to improving the thermal economic performance of the coolant.
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Key words:
- Lead-bismuth eutectic /
- Fuel bundle /
- Secondary flow /
- Entropy generation analysis
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图 1 燃料棒束结构平面示意图
P—燃料棒节距；D—燃料棒直径；d—绕丝直径；L—六边形外套管边长；H—绕丝螺距
Figure 1. Schematic Plan of Fuel Bundle Structure
图 4 相同功率下的不同工况轴向二次流强度变化
Z—笛卡尔坐标系中Z轴的距离
Figure 4. Change of Axial Secondary Flow Intensity under Different Conditions under the Same Power
图 5 相同Re不同功率下轴向二次流强度变化
Figure 5. Variation of Secondary Flow at Axial Direction with the Same Reynolds Number and Different Power
图 6 工况2下的截面温度梯度导致的熵产率分布
Figure 6. Distribution of Entropy Generation Rate Caused by Section Temperature Gradient under Condition 2
图 7 不同工况下的轴向传热熵产率波动
Figure 7. Fluctuation of Axial Heat Transfer Entropy Generation Rate under Different Conditions
图 8 由于流体粘性导致的无量纲熵产率分布
Figure 8. Distribution of Dimensionless Entropy Generation Rate Due to Fluid Viscosity
图 9 不同工况下轴向流动熵产率变化
Figure 9. Change of Axial Flow Entropy Generation Rate under Different Conditions
表 1 网格敏感性分析
Table 1. Sensitivity Analysis of Mesh
网格 网格数量/千万 Nu Ns/10−3 f 1 2.82 8.9971 0.2421 0.02029 2 3.35 9.1171 0.2458 0.02036 3 3.78 9.1539 0.2476 0.02049 4 4.37 9.1665 0.2496 0.02065 
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表 2 计算工况中
$ \dot m $ 与QTable 2.
$\dot m $ and Q in Calculation Condition工况 Re/104 $\dot m $(kg·s−1) Q /kW 1 0.5 2.4011 197.0 2 1.0 4.8022 197.0 3 1.5 7.2033 197.0 4 2.0 9.6045 197.0 5 4.0 19.2089 197.0 6 4.0 19.2089 98.5 7 4.0 19.2089 394.0 8 8.0 38.4178 197.0
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[1] 吕科锋. 液态铅铋合金在带统丝棒束组件内热工水力行为研究[D]. 合肥: 中国科学技术大学, 2016. [2] 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.2005.09.006 [3] CHAI X, LIU X J, XIONG J B, et al. CFD analysis of flow blockage phenomena in a LBE-cooled 19-pin wire-wrapped rod bundle[J]. Nuclear Engineering and Design, 2019, 344: 107-121. doi: 10.1016/j.nucengdes.2019.01.019 [4] SCHMANDT B, HERWIG H. Losses due to the flow through conduit components in mini-and micro-systems accounted for by head loss/change coefficients[C]//ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels Collocated with the ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting. Chicago: American Society of Mechanical Engineers, 2014: V001T02A002. [5] SCHMANDT B, HERWIG H. Diffuser and nozzle design optimization by entropy generation minimization[J]. Entropy, 2011, 13(7): 1380-1402. doi: 10.3390/e13071380 [6] JI Y, ZHANG H C, YANG X, et al. Entropy generation analysis and performance evaluation of turbulent forced convective heat transfer to nanofluids[J]. Entropy, 2017, 19(3): 108. doi: 10.3390/e19030108 [7] KÖNÖZSY L. A new hypothesis on the anisotropic Reynolds stress tensor for turbulent flows[M]. Cham: Springer, 2019. [8] PACIO J, DAUBNER M, FELLMOSER F, et al. Experimental study of heavy-liquid metal (LBE) flow and heat transfer along a hexagonal 19-rod bundle with wire spacers[J]. Nuclear Engineering and Design, 2016, 301: 111-127. doi: 10.1016/j.nucengdes.2016.03.003 [9] PAOLETTI S, RISPOLI F, SCIUBBA E. Calculation of exergetic losses in compact heat exchanger passages[J]. American Society of Mechanical Engineers. Advanced Energy Systems, 1989, 10(2): 21-29. -
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