共查询到19条相似文献,搜索用时 171 毫秒
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在核电厂的安全分析中,系统程序能够对多种事故瞬态进行瞬态分析。随着我国快堆技术的发展,在快堆系统程序的开发和应用等方面也做了一些工作。本文运用法国原子能委员开发的快堆系统分析程序DYN4G建立了中国实验快堆(CEFR)的系统模型,包括堆芯、一回路、二回路、汽水回路和事故余热排出系统,并计算了满功率下的稳态,与设计值进行了比对,同时完成了超功率事故的瞬态分析,并与《CEFR最终安全分析报告》中的计算进行了对比验证。计算结果表明程序能较好的模拟CEFR的稳态和超功率情况,为进一步开展CEFR的安全研究及钠冷快堆的安全分析打下了基础。 相似文献
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自然循环能力是衡量钠冷快堆固有安全性的重要指标,堆芯布置、回路设计及工况参数等都会影响堆芯自然循环能力,因此不同堆型的自然循环能力有很大差异。为了保证堆芯事故得到有效缓解,中国实验快堆(CEFR)的设计中通过优化系统布置,重点考虑了堆芯自然循环。本文采用SAS4A程序对CEFR进行系统建模,分析了CEFR在无保护失流(ULOF)工况下的堆芯热工水力参数瞬态特性,验证了CEFR利用自身自然循环和负反馈设计进行事故缓解的能力,本文还对一回路流动阻力和二回路钠装量对堆芯自然循环的影响进行分析。计算结果表明,CEFR具有良好的自然循环特性,在ULOF工况下可以依靠其负反馈停堆,并能够建立起稳定的自然循环从而导出堆芯余热。 相似文献
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转运-清洗室是中国实验快堆(CEFR)堆外换料系统中的主要设施,为反应堆换料操作提供一个安全可靠的密封和生物屏蔽空间,以保证操作人员的人身安全.本文采用数值方法对其进行力学分析.结果表明:CEFR转运-清洗室的力学性能满足规范要求. 相似文献
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《中国原子能科学研究院年报(英文版)》2018,(0)
正为满足中国实验快堆(CEFR)物理启动经济性需求,研究设计二次中子源替代堆内~(252)Cf源的可行性。选用Sb-Be二次中子源作为设计目标,借鉴压水堆及快中子增殖堆Sb-Be中子源成熟的运用经验及设计方案,参照CEFR相关物理参数,研究设计了几种Sb-Be二次中子源组件辐照方案。运用基于蒙特卡罗方法的MCNP程序模拟 相似文献
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针对中国实验快堆事故余热排放系统空气热交换器的国内外研究现状,结合中国实验快堆工程建设的需要,建立了空气热交换器的数学模型,对其在自然循环条件下的热工流体力学特性进行了分析研究. 相似文献
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通过实验研究了在液态金属快中子增殖堆中,主壳顶盖下部遮热体的组成形式对遮热体工作性能的影响。本文提出了一个考虑到使用经济性的遮热体组成方案,供建造我国第一座快中子堆(CEFR)时参考。另外,本文对取消遮热体而完全用强制对流冷却系统对堆顶盖施隔热保护的方案作了实验研究,给出了冷却流道平均Nusselt数计算公式,它对CEFR顶盖冷却系统的设计具有实用价值。 相似文献
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《Journal of Nuclear Science and Technology》2013,50(11):902-914
Decay heat removal capability under boiling condition was studied using an LMFBR fuel subassembly mockup loop. The sodium flow was driven by natural convection through the loop in which was installed a 37-pin bundle heated electrically over a length of 45 cm. The heat flux furnished by the pins was increased stepwise, upon which the two-phase flow regime changed from bubble to slug flow and then to annular or annular mist flow. Dryout occurred even in slug flow regime, but only momentarily, and permanent dryout was not observed before establichment of annular flow. A suitable criterion for permanent dryout is considered to be 0.5 average exit sodium vapor quality. The results indicated that upon occurrence of sodium boiling, the coolability of fuel subassembly would be maintained by natural convection after reactor shutdown. 相似文献
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Vaibhav Khane 《Nuclear Engineering and Design》2010,240(3):609-615
This research is an extension of the previous work on the development of an integrator (RC) circuit analogy for natural convection. This analogy has been proven experimentally as well as by numerical simulations. Additional Rayleigh-Bénard convection numerical simulations were performed to investigate ΔT (temperature difference between source and sink) dependence of the thermal resistance of a natural convection system. Our results suggest that analogous to voltage dependent resistor (VDR) in electrical engineering, ΔT dependent thermal resistance is observed in natural convection system. This ΔT dependent thermal resistance leads to a variable time constant. Moreover, this research also suggests that for a natural convection system, in addition to the thermal capacitance a kinetic energy capacitance also exists. The relative contribution of kinetic energy capacitance depends on Rayleigh number. These results provide significant step forward towards development of a new inexpensive modeling and transient analysis tool for a natural convection system. 相似文献
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Jan-Patrice Simoneau Julien Champigny Brian Mays Lewis Lommers 《Nuclear Engineering and Design》2007,237(15-17):1923-1937
A three-dimensional model has been constructed to simulate the passive heat removal in a modular prismatic-block high temperature reactor during a loss of active cooling accident. This model, developed using the STAR-CD general computational fluid dynamics code, solves the combined conductive, convective, and radiative heat transfer within a 30° section of the core and reactor vessel. To accommodate the different spatial scales, it uses homogeneous equivalent media to represent the coolant flow and the prismatic fuel blocks. A customized procedure that manages solving alternatively the dynamic and thermal fields permits the computation of very long transients, which typically are performed for 100 or more hours of simulated time.The global methodology and specific modeling procedures are explained, and key points of the CFD analysis are highlighted. Next, the results of several calculations are presented, and the physical phenomena represented are described. Two commonly investigated loss of active cooling scenarios are considered: depressurized conduction cooldown and pressurized conduction cooldown. The results for these two scenarios are compared to assess the effect of heat transfer via internal natural convection – which is negligible during the depressurized event – on the thermal behavior of the system. In addition, the evolution of the natural convection flow through the core and in the annular spaces is examined and discussed. 相似文献
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基于辐射-对流-传导的热流固耦合计算流体动力学(CFD)模型,对比不同放置状态、环境温度、容器内部填充介质和有无环形翅片情况下,各部件最高温度、自然对流流速、外表面辐射及对流功率的变化。结果表明,水平放置有利于强化环形翅片的对流传热;环境温度每升高10℃,燃料包壳温度增加6.5℃,外壁面温度增加8.3℃;燃料篮内部填充物由中子吸收板或铝块更换为氦气后,容器整体导热性能明显降低,容器内部温度升高,但容器壁面温度基本不变;如不考虑太阳暴晒,环形翅片可增加对流传热,使得容器整体温度降低;如考虑太阳暴晒,环形翅片会增加太阳暴晒能量的吸收,使容器整体温度反而比光滑壁面容器高;基于代数分析法和漫灰表面模型对CFD辐射模型进行验证,CFD辐射功率和公式法计算结果基本一致。 相似文献
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对环形窄缝通道内单相水在双面处于不同的加热热流密度情况下的对流换热特性进行了数值计算.计算结果表明,环形通道内、外壁加热热流密度比值的不同,对环形通道内、外壁与单相水的对流换热特性有着显著的影响.内、外壁面加热热流密度比值较小时,内壁的换热强于外壁的换热,随着内壁加热热流密度的增大,外壁的换热得到增强.但是,当内、外壁加热热流密度比值增加到一定程度时,外壁的对流换热特性将超过内壁的对流换热特性,与文献报道的实验结果一致.此外,环缝间隙的减小将导致环形通道的换热性能下降. 相似文献