LOCA事故时碎片堆积引起的水头损失估算
发布时间：2020-12-13 05:53
在发生失水事故(LOCA)或主蒸汽管道破裂事故(MSLB)时,在破口处由于水流喷射和随后高温高压蒸汽的泄漏可能会产生大量不同类型的碎片,如颗粒碎片,潜在的纤维碎片和化学碎片。这些碎片会流向堆芯应急冷却系统(ECCS)或安全壳再循环系统(CRS),可能会附着在地坑滤网上并造成一定的压头损失。其中有部分颗粒碎片可旁通地坑滤网进入一回路系统,影响堆芯冷却剂流道并引起燃料组件压降增加。这些颗粒碎片堆积在燃料组件内,可能会阻碍核电厂堆芯长期冷却(LTCC)的能力。美国核管会(U.S.NRC)规定在运行的商用核电厂必须能够证明其LOCA后能保证堆芯长期冷却。综上所述,研究不同工况下燃料组件内的颗粒碎片对于分析碎片在组件内的分布情况并得到压头损失这一关键参数从而避免发生堆芯熔毁事故具有必要性。针对压水堆AP1000燃料组件(全尺寸组件)由华北电力大学核科学与工程学院搭建了试验测试回路,用于分析不同量的颗粒,纤维,化学沉淀物添加至试验回路后对燃料组件造成的压降影响。本论文的研究目的是记录试验获得的数据并处理,建立CFD模型用于研究导致LTCC失效的堆积在燃料组件内碎片的关键参量。
【文章来源】：华北电力大学(北京)北京市 211工程院校 教育部直属院校
【文章页数】：76 页
【学位级别】：硕士
【文章目录】：
摘要
Abstract
Nomenclature
Chapter 1. Introduction
1.1 Background
1.2 Significance
1.3 Literature Review
1.4 Research Plan
1.4.1 Critical Issues
1.4.2 Methodology
1.4.3 Outline of work
1.5 Thesis Outline
Chapter 2. Loss of Coolant Accident （LOCA）, Emergency Core CoolingSystem （ECCS） & Debris Generation
2.1 Emergency Core Cooling System
2.1.1 Requirements for an ECCS
2.2 Debris Generation and Transport
Chapter 3. Theory of CFD
3.1 Computational Fluid Dynamics
3.2 Advantages of CFD
3.3 Concept of CFD
3.4 Performing a CFD Analysis
3.5 Multiphase Modeling
3.5.1 Eulerian Model
3.6 Turbulence Modelling
3.7 Standard,RNG,and Realizable k-ε Models
3.7.1 Transport Equations for the Standard k-ε Model
3.8 Discrete Phase Model
3.8.1 Limitations of Discrete Phase Model
Chapter 4. Experimentation & Ressults
4.1 Theory
4.2 Experimental facility
4.3 Debris preparation and Test procedure
4.4 Uncertainty in the Experimental Measurements
4.5 RESULTS AND DISCUSSION
4.5.1 Initial Data of Test Loop
4.5.2 Debris Addition Method
4.5.3 The Effect of Concurrent Addition
4.5.4 Effect of Sequential Debris Addition
4.5.5 Comparison and Discussion
4.5.6 Fiber Debris Sensitivity
4.5.7 Flow rate
Chapter 5. CFD Analysis & Results
5.1 Geometry
5.2 Meshing
5.3 Discrete Phase Model （Case 1）
5.3.1 Single Injection
5.3.2 Batch Injection
5.3.3 Single and Dual Particle Type Injection
5.4 Porous Medium Model （Case 2）
5.4.1 Porous Medium Bed Thickness vs Pressure Drop
5.4.2 Inlet Flow-rate vs Pressure Drop
5.4.3 Void Fraction vs Pressure drop
5.4.4 Realizable and Observed Trend
Chapter 6. Conclusions and Discussion
6.1 Conclusions
6.2 Discussion
References
Acknowledgement
本文编号：2914028
【文章来源】：华北电力大学(北京)北京市 211工程院校 教育部直属院校
【文章页数】：76 页
【学位级别】：硕士
【文章目录】：
摘要
Abstract
Nomenclature
Chapter 1. Introduction
1.1 Background
1.2 Significance
1.3 Literature Review
1.4 Research Plan
1.4.1 Critical Issues
1.4.2 Methodology
1.4.3 Outline of work
1.5 Thesis Outline
Chapter 2. Loss of Coolant Accident （LOCA）, Emergency Core CoolingSystem （ECCS） & Debris Generation
2.1 Emergency Core Cooling System
2.1.1 Requirements for an ECCS
2.2 Debris Generation and Transport
Chapter 3. Theory of CFD
3.1 Computational Fluid Dynamics
3.2 Advantages of CFD
3.3 Concept of CFD
3.4 Performing a CFD Analysis
3.5 Multiphase Modeling
3.5.1 Eulerian Model
3.6 Turbulence Modelling
3.7 Standard,RNG,and Realizable k-ε Models
3.7.1 Transport Equations for the Standard k-ε Model
3.8 Discrete Phase Model
3.8.1 Limitations of Discrete Phase Model
Chapter 4. Experimentation & Ressults
4.1 Theory
4.2 Experimental facility
4.3 Debris preparation and Test procedure
4.4 Uncertainty in the Experimental Measurements
4.5 RESULTS AND DISCUSSION
4.5.1 Initial Data of Test Loop
4.5.2 Debris Addition Method
4.5.3 The Effect of Concurrent Addition
4.5.4 Effect of Sequential Debris Addition
4.5.5 Comparison and Discussion
4.5.6 Fiber Debris Sensitivity
4.5.7 Flow rate
Chapter 5. CFD Analysis & Results
5.1 Geometry
5.2 Meshing
5.3 Discrete Phase Model （Case 1）
5.3.1 Single Injection
5.3.2 Batch Injection
5.3.3 Single and Dual Particle Type Injection
5.4 Porous Medium Model （Case 2）
5.4.1 Porous Medium Bed Thickness vs Pressure Drop
5.4.2 Inlet Flow-rate vs Pressure Drop
5.4.3 Void Fraction vs Pressure drop
5.4.4 Realizable and Observed Trend
Chapter 6. Conclusions and Discussion
6.1 Conclusions
6.2 Discussion
References
Acknowledgement
本文编号：2914028
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