Preliminary safety analysis for the SCWR-FQT facility

In recent years, a substantial number of theoretical, numerical and experimental R&D activities are carried out on the supercritical water-cooled reactor (SCWR), which proposed as one of the Generation IV nuclear power plants by the Generation IV International Forum (GIF). A research plan has been proposed by GIF on the designing and licensing of a SCWR prototype, which is planned to be constructed and operated in the near future. In the preliminary stage of this research plan a fuel assembly, with its experimental loop, will be constructed and tested in SCWR operating conditions. This article reviews the research activities carried out in the Supercritical Water Reactor Fuel Qualification Test (SCWR-FQT) project in Europe and Super Critical Reactor In-Pipe Test Preparation (SCRIPT) project in China. These research activities studied both neutronic and thermal–hydraulic behavior of the test fuel assembly and auxiliary systems of SCWR fuel test facility. CFD simulations, subchannel analysis and system simulations coupled with neutronics code are performed to study the performance of the tested fuel assembly, especially safety related aspects.     

水冷式表面冷却器优化建模

通过分析比较,取最低年综合费用作为优化设计目标函数,并在一定的约束条件下,针对某型号表面冷却器,建立年综合费用与表面冷却器结构参数之间的函数关系,即表面冷却器优化设计数学模型,为实现表面冷却器及相关部件的合理匹配提供了一定的参考数据。     

流道截面参量对微通道水冷镜热变形的影响

采用将有限体积法求解三维层流传热方程获得的温度场耦合到ANSYS进行热变形分析的方法,研究了流道截面形状和尺寸对微通道水冷镜内传热现象和镜面热畸变的影响。计算了矩形、梯形、圆形3种截面形状以及3种不同水力直径(百微米量级)下微通道水冷镜的平均换热系数、温升和镜面热变形。结果表明,同一条流道,各壁面温度并不随激光辐照面和镜面呈对称分布,最高温度偏向下游;侧壁的换热系数最大,且沿水流方向逐步减小;流道距进水口距离越大,其换热系数越小。在3种截面形状微通道中,减小截面尺寸可获得较大换热系数,且梯形截面微通道水冷镜能获得最小的镜面热变形量,在热流密度为14730 W/m2,水力直径为239μm,入口速度为2.54m/s的条件下,其镜面热变形仅为0.016μm。     

超临界流体的泄压过程研究

超临界水堆(SCWR)的LOCA研究是安全分析的重点和难点,其中压力容器的喷放泄压过程的研究至关重要。本文通过对反应堆压力容器进行简化,建立了简单容器喷放的数学物理模型,开发了超临界流体的喷放瞬态计算程序。将该程序的计算结果与超临界二氧化碳的泄压喷放过程的实验数据进行了比较,计算值与实验结果吻合良好,验证了模型的正确性。运用该验证后的程序对超临界水的容器喷放过程进行了深入研究和分析,分析了不同初始条件、破口面积及加热功率等对泄压过程瞬态特性的影响。结果表明,本文建立的简单容器模型能模拟从超临界到亚临界压力的喷放泄压过程。计算结果可为超临界水堆的LOCA分析提供理论基础。     

高热密度水冷机柜制冷系统的方案设计与应用

高热密度水冷机柜制冷系统能有效解决超级计算机刀片服务器的散热问题。系统包含初级和次级2个独立的水循环,具有智能热交换控制功能的热交换柜使其互相隔离,控制冷却水温度始终高于露点温度,从而防止机房内凝结水析出的风险。全密闭式水冷机柜作为制冷和散热终端,柜内空气循环系统采用正面送风、背面排风的形式。系统具有制冷量大、制冷效率高、稳定可靠等特点。     

Microstructural evolution in nickel alloy C-276 after Ar ion irradiation

Irradiation damage in nickel alloy C-276 irradiated by 115 keV argon ions at room temperature with irradiation doses from 0.28 to 82.5 dpa has been investigated by transmission electron microscopy. Nano-scale black spot damage appeared at a dose higher than 0.83 dpa. Large interstitial-type dislocation loops were observed at the dose of 8.25 dpa. Both the density of dislocation loops and the density of network dislocations grew significantly with the increase of irradiation dose. However, the density of network dislocations declined at the dose of 27.5 dpa. But the total of dislocation density (density of dislocation lines plus density of dislocation loops) kept increasing and no signs of saturation were seen in the dose range explored. The results showed that the nickel alloy C-276 had good performance in delaying the development of black spots, dislocations and dislocation loops. However, original grains have formed into subgrains at the dose of 82.5 dpa, meaning that the grains in C-276 lost its structural integrity at doses higher than 82.5 dpa.     

ANSYS软件在矿热炉水冷出铁口设计中的应用

为获得矿热炉水冷出铁口合理的设计参数,采用ANSYS软件建立水冷出铁口及普通出铁口三维物理模型并模拟稳态温度场,同时根据传热学原理,进行了炭素耐材侵蚀机理的分析。结果表明：生产硅钙合金矿热炉出铁口的侵蚀线约为1 100℃等温线;普通出铁口温度场中1 100℃以上等温线所覆盖区域约占总体积62%,水冷出铁口约占35%;出铁口中冷却装置和炭砖之间的填充材料是关键,材料的导热系数不能小于3 W/（m·k）。     

中冷器对非道路柴油机性能影响的对比研究

随着非道路移动工程机械发动机机功率的不断增加,为满足柴油机的动力性和经济性指标,对增压空的气冷却提出了越来越高的设计要求。本文通过场地试验的方法对比研究了水冷中冷器与空冷中冷器对某款装载机柴油机工作特性的影响。试验结果表明,水冷中冷器相比于传统的风冷中冷器能更有效的降低柴油发动机的进气温度:水冷中冷器在铲装作业和高速跑工况下增压空气平均出温分别比空冷中冷器低27.6%和10.5%,柴油机扭矩提升为1.6%和6.3%,并且油耗降低了4.0%和2.5%。相对进气压力对柴油机经济性指标有一定影响,适当增加进气压力可以减少油耗。     

水冷螺杆机组热回收的设计与应用

以水冷螺杆机组的热回收机制为研究基础,对影响热回收效率的几个重要因素进行详细的比较分析,确定相关因素的影响规律,并提出改善热回收设计与应用的措施。     

Modeling and energy simulation of the variable refrigerant flow air conditioning system with water-cooled condenser under cooling conditions

As a new system, variable refrigerant flow system with water-cooled condenser (water-cooled VRF) can offer several interesting characteristics for potential users. However, at present, its dynamic simulation simultaneously in association with building and other equipments is not yet included in the energy simulation programs. Based on the EnergyPlus's codes, and using manufacturer's performance parameters and data, the special simulation module for water-cooled VRF is developed and embedded in the software of EnergyPlus. After modeling and testing the new module, on the basis of a typical office building in Shanghai with water-cooled VRF system, the monthly and seasonal cooling energy consumption and the breakdown of the total power consumption are analyzed. The simulation results show that, during the whole cooling period, the fan-coil plus fresh air (FPFA) system consumes about 20% more power than the water-cooled VRF system does. The power comparison between the water-cooled VRF system and the air-cooled VRF system is performed too. All of these can provide designers some ideas to analyze the energy features of this new system and then to determine a better scheme of the air conditioning system.