中国实验快堆泵支承冷却系统温度场分析

中国实验快堆一回路泵支承套筒是承重设备,位于高温的热钠池中.为了限制套筒和套简内部冷钠腔室的钠温度,维持主泵正常工作温度,设置钠泵支承冷却通道.利用计算流体动力学技术(CFD),对泵支承冷却系统进行三维模拟,通过对泵支承冷却系统冷却流道和支承结构的数值传热分析,得到了该系统的温度场分布情况,验证了泵支承冷却系统的冷却能力.     

异径布管夹持支撑结构换热器壳侧场协同分析

针对折流杆结构换热器只有在较高壳侧流速时才能达到较高传热效率、布管不紧凑、不能很好抵抗变化工况等缺点,提出以大小两种规格换热管和夹持支撑结构代替传统的折流杆支承元件,达到提高壳侧传热系数,增加换热面积.利用CFD软件建立单元流道,对壳侧流场和传热场进行了三维数值模拟,提出了复杂结构的纵流换热器壳侧速度.温度梯度场矢量夹角的计算方法,得到了壳侧速度场和温度梯度场的场协同角的定量关联式,证实了新结构具有更好的场协同关系.     

基于相似理论的快堆氩气空间温度场实验研究

本文在实验装置上研究了池式快堆主容器内氩气空间温度分布特性。实验结果表明,气体温度在封闭空间中间大部分区域维持一个相对恒定的温度,这是封闭空间内液面自然对流换热的固有特点。根据实验结果分析,提出了氩气空间高度和主容器冷却系统设计应统筹考虑的设计思想,可用于优化池快堆主容器肩部设计,对大型快堆主容器冷却系统优化设计具有参考意义。     

板壳支承结构的减振设计研究

对板壳支承结构提出了阻振质量、框式改进和弹性隔振3种减振措施,开展减振方案设计,并建立改进支承结构与原支承结构数值模型,以泵类设备振动激励作为输入,分析振动从支承结构向外壳的传递特性,采用数值方法研究3种改进设计方案的减振效果。结果表明,3种减振措施对泵类设备振动通过支承结构向外壳传递的衰减效果分别最高可达3、10、40 d B,考虑工程特性参数和质量比一定时,阻振质量工程适应性最强,但减振效果有限,弹性隔振效果显著,但工程使用难度较大,框式支承则兼顾了减振效果和工程参数影响,具有较强工程应用前景。     

铜—康铜热电偶和通风防辐射装置在大气扩散实验中的应用

大气湍流结构与温度层结密切相关垂直温度梯度资料可作为衡量大气湍流状况的一个指标。因此,在大气扩散实验的气象背景考察中,要进行垂直温度梯度观测其目的旨在确定大气热力稳定度,了解温场的空间分布和时间上的变化,摸清抑制污染物稀     

蒸汽发生器主给水管道不同位置断裂后设备冷却水系统泵厂房漫流特性分析

核电厂蒸汽发生器主给水管道横跨设备冷却水系统（CCS）泵厂房,其中布置有柴油机、泵等重要设备。在CCS泵厂房发生蒸汽发生器主给水管道双端破裂事故工况下,需保证布置在CCS泵厂房内的CCS泵组不会因为水淹而造成失效,因此,需要对该漫流特性进行评价分析。已有研究大多关注管道破裂后流体高速喷射行为,而较少研究喷射流体在CCS泵厂房中漫流积淀情况,同时由于设备冷却水系统泵厂房空间尺寸巨大、结构复杂,很难开展原型尺寸实验研究。因此分别对破管位置位于CCS泵厂房5.334 m层空间和CCS泵厂房11墙与近核岛侧防甩墙之间的压力隔间两类事故场景分别进行三维数值计算。模拟结果表明：在蒸汽发生器双端断裂触发跳泵事故下,泄放水流量在11 s内即迅速下降,破口位置处于5.334 m层空间和压力隔间两类条件下均不会淹没CCS泵防水台,不影响CCS泵的正常运行。破口位于5.334 m层空间位置时设计预留开孔能有效排出漫流的泄放水;破口位于压力隔间内时设计的钢格栅也能有效排出漫流的泄放水。本研究为CCS泵厂房空间设备冷却水系统泵厂房防水淹策略优化设计提供重要数值参考。     

200MW核供热堆堆芯燃料元件盒冷却剂出口温度测量方法实验研究

提出了将200MW核供热堆芯燃料元件盒支承格子板的一个侧面设计成空交沟槽结构,并在其中放置铠装热电偶测量堆芯燃料元件盒冷却剂出口温度的设计方案。经实验表明,支承格子板侧面空间正交沟槽结构,不仅能有效地导流冷却剂,而且增长了铠装热电偶的感温长度,减小了测导热损失误差,从而提高了测量精度。因此,其测量方法能满足工程上对温度测量精度的要求。     

秦山核电二期工程反应堆压力容器支承设计

根据总体设计要求和设计输入要求,进行了秦山核电二期工程反应堆压力容器支承的结构设计和力学设计.介绍了该反应堆压力容器支承结构的材料及性能指标.通过分析计算表明,该设计满足总体设计的要求.     

华龙一号某机组主泵推力轴承优化改进分析

华龙一号某机组三轴承结构设计的主冷却剂泵（简称主泵）在进行小流量试验时,出现推力轴承磨损问题,通过对主泵推力轴承结构进行分析,利用鱼骨图根本原因分析方法,对导致推力轴承磨损的可能原因进行逐一排查分析,根据排查结果,提出采用多喷嘴联合供油设计、在主推力轴承和副推力轴承的油膜吸入口处增加吸油倒角设计、在原有顶轴油设计基础上增加反向副推力轴承顶轴油结构设计、建立推力轴承温度-油温的综合测量系统及采用弹簧板主动补偿式推力轴承支撑结构等改进方法。经试验验证,改进后的主泵推力轴承系统显著提升了华龙一号某机组主泵的运行可靠性和固有安全性。      

5MW低功率堆本体结构设计

本文介绍了5MW 低功率反应堆(5MW LPR)本体结构设计的指导思想、材料选择、工艺参数、堆芯布置及结构特点。堆本体是反应堆的核心部分,设计的内容包括燃料元件、控制棒、反射层、辐照管、屏蔽、核测量装置的结构和布置,堆芯支承形式和堆内构件的装配等。     

CFR600乏组件转换桶内氩气空间三维传热数值模拟

利用商业计算流体力学程序STAR?CCM+,对中国示范快堆（CFR600）乏组件转换桶内的氩气空间及相关结构部件进行数值模拟计算,验证分析正常工况和事故工况下的预埋件的热工设计。研究结果表明,正常工况下预埋件的温度峰值满足设计限值要求,但预埋件的温度分布存在一定程度的不均匀性,并且当发生事故工况时温度分布的差异性明显增大。钠液面通过辐射换热和对流换热共同对设备构件产生影响,其中辐射换热起主要作用。对于钠液面辐射换热的主要决定因素为钠液面的发射率。本工作为乏组件转换桶的正常运行及安全分析提供了技术准备。     

Cellular convection in vertical annuli of fast breeder reactors

In the pool type fast reactors the roof structure is penetrated by a number of pumps and heat exchangers that are cylindrical in shape. Sandwiched between the free surface of sodium and the roof structure, is stagnant argon gas, which can flow in the annular space between the components and roof structure, as a thermosyphon. These thermosyphons not only transport heat from sodium to roof structure, but also result in cellular convection in vertical annuli resulting in circumferential temperature asymmetry of the penetrating components. There is need to know the temperature asymmetry as it can cause tilting of the components. Experiments were carried out in an annulus model to predict the circumferential temperature difference with and without sodium in the test vessel. Three-dimensional analysis was also carried out using PHOENICS CFD code and compared with the experiment. This paper describes the experimental details, the theoretical analysis and their comparison.     

CFD analysis of heat transfer in subchannels of a Super Fast Reactor

This paper presents CFD analyses of heat transfer in subchannels of a Super Fast Reactor fuel assembly. Analyses are concentrated on the circumferential temperature distribution on the cladding outer surface because the Maximum Cladding Surface Temperature (MCST) has been a crucial design parameter to evaluate fuel cladding integrity of the Super Fast Reactor. Speziale non-linear high Re k-? model, which can reproduce the anisotropic turbulence flow in non-circular flow channels, with two-layer near-wall treatment is adopted. The results show that heat conduction in the cladding should be considered in the CFD analyses. Larger circumferential temperature gradient occurs on the cladding surface in the edge and corner subchannels than that in the ordinary subchannel because of their special geometries causing larger heterogeneity of mass flow rate distribution inside the subchannels. Improved subchannel configurations to reduce the circumferential temperature gradient are proposed. This study will be a good guideline to the future core design improvement.     

Structural considerations for a Tokamak fusion reactor

Several preliminary structural analyses are presented which validate a design for the experimental power reactor. Three components are singled out as requiring special attention: the magnetic coils, the blanket support structure, and the blanket modules. Repeated loading of a coil structure by magnetic forces should produce only linear elastic deformation. An analysis for minimum preload necessary to ensure this is presented. Using axisymmetric thin shell theory, a stress analysis of the blanket support structure is described. To account for the welded ring structure, a perforated plate analysis is used to compute the structural displacements and the ligament stresses. Temperature distributions and thermal stresses in the blanket module are determined using both finite element and analytical analysis. The stresses are all acceptable, including the effects produced by creep and fatigue. Thermal stress in the liner produced by a nonlinear temperature gradient is also shown to be acceptable.     

一种适用于新堆的零泄漏循环泵

磁力泵近年来发展迅速,具有零泄漏、结构简单、成本低和维修方便等优点.通过结合部分应用于核能条件下的试验和结构设计研究,研制了既满足高温高压运行、又做到零泄漏等要求的新型循环泵,并对其在新堆或研究堆上的应用前景进行了分析和研究.在一定条件下,磁力泵完全可取代目前大多采用的轴封泵、屏蔽泵和机械密封泵等,达到了简化系统配置、便于维修更换和降低设备成本的目的.     

Target area structural design of ShenGuangIII

This paper will present a summary of the target area structural design results of ShenGuangIII (SGIII), which includes target bay and switchyard support structures, target chamber, and beam transport system. The target area building is rectangular and includes a target bay and a switchyard. The outer wall of the target area building is based outside the vibration isolation trenches and separates the diurnal temperature loads and the wind loads that occur outside the target area building during the alignment process prior to a shot. The target bay and switchyard support structures are mainly comprised of the steel reinforced concrete building and the steel space frame. The target chamber is a welded sphere made of aluminum alloy 5052 and has an inner diameter of 6 m and a nominal wall thickness of 8 cm. The beam transport system brought the 48 laser beams to the final optics assemblies (FOAs) and includes 276 transport mirrors. Sources that influence stability are mainly ambient random vibration, ambient wind induced vibrations, diurnal temperature changes, and HVAC. A FEM is used to calculate the responses of the target area structure under broadband ambient random vibration. The position deviations of 48 beam lines are calculated and used to evaluate the stability of the target area structure. The analyses demonstrated that the positioning deviations of 48 beam lines satisfy the deviation budget requirements.     

高温熔盐泵散热器的数值优化与热分析

为提高高温熔盐泵散热器的散热效果,对影响散热器散热面积的重要因素——散热孔的直径和数量进行了数值优化,并将数值模拟得到的热载荷加载到结构体上,分析了热载荷下的热变形。结果表明:散热孔直径为12 mm、散热孔数量为6时,散热流体的流动均匀稳定,泵轴和散热器的综合散热效果较好,最终泵轴顶端的平均温度可降到440 K,散热器顶端的平均温度可降到417.5 K,满足散热需求;泵轴热变形量较小,最大值为0.46 mm,散热器的变形量较大,最大值为2.37 mm,加工时必须考虑材料的热膨胀和热变形。     

Comparison of double layer in argon helicon plasma and magnetized DC discharge plasma

We present in this paper the comparison of an electric double layer (DL) in argon helicon plasma and magnetized direct current (DC) discharge plasma. DL in high-density argon helicon plasma of 13.56 MHz RF discharge was investigated experimentally by a floating electrostatic probe and local optical emission spectroscopy (LOES). The DL characteristics at different operating parameters, including RF power (300–1500 W), tube diameter (8–60 mm), and external magnetic field (0–300 G), were measured. For comparison, DL in magnetized plasma channel of a DC discharge under different conditions was also measured experimentally. The results show that in both cases, DL appears in a divergent magnetic field where the magnetic field gradient is the largest and when the plasma density is sufficiently high. DL strength (or potential drop of DL) increases with the magnetic field in two different structures. It is suggested that the electric DL should be a common phenomenon in dense plasma under a gradient external magnetic field. DL in magnetized plasmas can be controlled properly by magnetic field structure and discharge mode (hence the plasma density).     

Preliminary structural evaluations of the STAR-LM reactor vessel and the support design

In this paper, preliminary structural evaluations of the reactor vessel and support design of the STAR-LM (The Secure, Transportable, Autonomous Reactor – Liquid Metal variant), which is a lead-cooled reactor, are carried out with respect to an elevated temperature design and seismic design. For an elevated temperature design, the structural integrity of a direct coolant contact to the reactor vessel is investigated by using a detail structural analysis and the ASME-NH code rules. From the results of the structural analyses and the integrity evaluations, it was found that the design concept of a direct coolant contact to the reactor vessel cannot satisfy the ASME-NH rules for a given design condition. Therefore, a design modification with regards to the thermal barrier is introduced in the STAR-LM design. For a seismic design, detailed seismic time history response analyses for a reactor vessel with a consideration of a fluid–structure interaction are carried out for both a top support type and a bottom support type. And from the results of the hydrodynamic pressure responses, an investigation of the minimum thickness design of the reactor vessel is tentatively carried out by using the ASME design rules.