在质量交换器中通过铅氧化物球的填充床估算铅—铋共流的侵蚀

发布时间：2024-05-30 02:13

　　铅铋合金(LBE),由于其良好的热物理、材料和化学性质,被认为是加速器驱动次临界系统(ADS)中冷却剂的合适选择。然而,以铅铋合金(LBE)作为主要冷却剂的快堆装置需要控制溶解氧活性以保护结构材料同时避免冷却剂中的氧气积聚。LBE中的氧浓度应高于结构材料上存在的保护性氧化物层的溶解极限,且应低于LBE中氧的溶解度极限以避免氧化铅沉淀。氧化铅质量交换器(PbO MX)可用来避免系统内过量氧化和固体氧化物形成。质量交换器(PbO MX)包含氧化铅球的填充床,这些氧化铅球机械稳定且随机排列在圆柱形容器中。在Pb0层前后放置氧化铝球以产生速度分布。质量交换器是通过冷却剂流经氧化铅球床的过程来提供氧。LBE流经Pb0球导致流动侵蚀,当LBE中的氧浓度饱和时,这类侵蚀成为质量交换器中Pb0重量损失的主要原因。本研究的重点是通过数值模拟估算LBE流动引起的侵蚀。使用计算流体力学软件CFD作为分析工具研究该过程。涉及的主要步骤包括预处理,计算求解和后处理,侵蚀是一个复杂的现象,取决于许多因素。因此,还进行了参数研究以观察颗粒大小、粒径和粒子浓度对侵蚀速率的影响。该研究的模拟在ANSYS Fluent中...

【文章页数】：57 页

【学位级别】：硕士

【文章目录】：
摘要
ABSTRACT
CHAPTER 1. INTRODUCTION
    1.1 NUCLEAR ENERGY
    1.2 EVOLUTION OF NUCLEAR POWER
    1.3 LEAD-COOLED FAST REACTOR
        1.3.1 Research and Development in LFRs
        1.3.2 Structural Corrosion in LFRs
    1.4 RESEARCH GOAL AND ITS SIGNIFICANCE
    1.5 RESEARCH METHODOLOGY
CHAPTER 2. LITERATURE REVIEW
    2.1 INTRODUCTION
    2.2 OXYGEN CONTROL IN LBE
    2.3 LEAD OXIDE MASS EXCHANGER (PBO MX)
    2.4 WORLDWIDE RESEARCH STATUS
        2.4.1 Brief History
        2.4.2 Progress in Last Decade
    2.5 EROSION
        2.5.1 Stages of Erosion
        2.5.2 Important Parameters
        2.5.3 Particle impact erosion
    2.6 PACKED BEDS
        2.6.1 Geometric Properties of Packed Beds
        2.6.2 Packing Regimes
    2.7 FLOW THROUGH PACKED BEDS
    2.8 MODELLING OF PACKED BEDS
CHAPTER 3. COMPUTATIONAL FLUID DYNAMICS
    3.1 INTRODUCTION
    3.2 APPLICATIONS OF CFD
    3.3 ADVANTAGES OF CFD
    3.4 ELEMENTS OF CFD
        3.4.1 Pre-processing
        3.4.2 Solving
        3.4.3 Post-Processing
    3.5 GOVERNING EQUATIONS
        3.5.1 Conservation Equations
        3.5.2 General Transport Equation
    3.6 TURBULENCE MODELLING
    3.7 RANS MODEL
        3.7.1 Boussinesq Hypothesis
        3.7.2 Eddy Viscosity Models
    3.8 SELECTION OF APPROPRIATE TURBULENCE MODELS
CHAPTER 4. MODELLING AND ANALYSIS
    4.1 INTRODUCTION
    4.2 METHODOLOGY
    4.3 ASSUMPTIONS AND UNCERTAINTIES
    4.4 GEOMETRIC MODEL
    4.5 MESH GENERATION
        4.5.1 Mesh Quality
        4.5.2 Mesh Quality Metrics
        4.5.3 Grid Independency
    4.6 PRELIMINARY MODEL SELECTION
        4.6.1 Turbulence Model Selection
        4.6.2 Near Wall Treatment
    4.7 DISCRETE PHASE MODEL
    4.8 SOLVER SETTINGS AND BOUNDARY CONDITIONS
CHAPTER 5. RESULTS AND DISCUSSION
    5.1 EFFECT OF PARTICLE VELOCITY
    5.2 EFFECT OF PARTICLE DIAMETER
    5.3 EFFECT OF PARTICLE CONCENTRATION
CHAPTER 6. CONCLUSION AND FURTHER WORK
    6.1 CONCLUSION
    6.2 RECOMMENDATION FOR FUTURE WORK
REFERENCES
ACKNOWLEDGEMENTS
PUBLICATIONS



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