HTR-10主氦循环风机的设计、试验和运行

主氦循环风机是10MW高温气冷实验堆(HTR-10)的关键设备,在250℃、3．0MPa的氦气气氛下将反应堆的热能输送到蒸汽发生器。针对反应堆的特殊要求,主氦循环风机的设计包括总体结构、叶轮型式、冷却系统．轴承,测量仪表、电气贯穿件和隔断阀对设计制造的主氦循环风机进行了出厂试验和安装后的冷、热态性能试验。按照反应堆的调试要求,主氦循环风机随反应堆的调试进行了初步运行。试验和运行结果表明,主氦循环风机达到了设计要求,能满足HTR-10的运行要求。     

高温堆磁悬浮轴承备用氦风机热工实验研究

高温堆磁悬浮轴承支承的备用氦风机是国内首次磁悬浮轴承的工业级应用,也是世界上首次将磁悬浮轴承应用在反应堆领域.为了验证磁悬浮轴承氦风机在热态工况下的性能以及整套系统的可靠性,进行了磁悬浮轴承氦风机的台架实验.在磁悬浮轴承氦风机的热工实验中,通过静态加热、动态加压、动态加热等实验,证明系统能够在热态工况下稳定运行,最后,磁悬浮轴承氦风机顺利通过了100 h热态考核出厂实验.     

HTR-10主氦风机停止试验的模拟

10MW高温气冷实验堆(HTR-10)是我国第1座模块式高温气冷堆。主氦风机停止试验是HTR-10的调试试验之一,该试验不仅证明了丧失强迫循环冷却时反应堆的安全性,也为系统分析程序的验证提供了实测数据。基于实际的试验工况,利用THERMIX程序对主氦风机停止试验进行了模拟,分析了反应堆主要参数的变化。对于反应堆功率,计算结果与试验结果符合得很好,证明了程序的正确性、合理性和适用性。试验过程中,燃料元件中心最高温度始终低于1 230℃的温度限值。     

HTR-10备用主氦风机更换方案设计

采用备用磁轴承主氦风机替代目前使用的滚动轴承主氦风机是10 MW高温气冷堆(HTR-10)的重要技术革新.通过对两风机的比较及一回路舱室剂量场测量验证了操作可行性,提出了舱室内拆装和舱室外拆装两种更换方案,并使用三维数字模拟技术对两种方案进行了仿真.通过对安全性、工作难度、工作量等方面的综合评估,认为舱室外拆装方案可行性较强.     

主氦风机进气段改型设计

应用三维定常湍流数值模拟技术和基于雷诺时均方法的剪切力输运κ-ω湍流模型封闭方程组,对主氦风机进气段的内部流动进行数值模拟计算,分析流动损失产生的原因.在此基础上对主氦风机进气段进行改型设计,结果表明,主氦风机进气段内部损失主要由内部流动的脱离和旋涡等造成;改型设计后得到的最优进气段的流动损失减小56.3％,达到工程要...     

高温气冷堆主氦风机惰转特性研究

高温气冷堆主氦风机与压水堆主泵一样,均为反应堆一回路的关键设备.在反应堆正常工况下,两者具有相同的功能要求,但在事故工况时,因反应堆的运行特性不同,其功能要求各异.目前,对压水堆主泵的惰转特性已有大量的实验研究和实际运行结果,但有关主氦风机惰转特性的实验研究与理论研究还很缺乏.本文结合风机的气动特性与高温气冷堆一回路的阻力特性,从理论上研究高温气冷堆主氦风机的惰转特性,建立主氦风机惰转时的流量与转速的预测公式,并给出其数值预测结果,为高温气冷堆设计的初步安全分析提供依据.     

主氦风机叶片扩压器进口安装角优化设计研究

针对主氦风机结构,建立包括主氦风机叶轮和叶片扩压器的数值研究平台。利用该数值研究平台对主氦风机叶片扩压器进口安装角进行优化设计。结果表明,设计工况下,叶片扩压器的最优进口安装角为13°,此时主氦风机静压升254 k Pa,多变效率达到91%。设定叶片扩压器进口安装角为13°,利用数值研究平台对主氦风机变流量特性进行研究。结果表明,设计流量下主氦风机性能最优,70%设计流量至120%设计流量为较优运行范围,120%设计流量至140%设计流量下压升不满足设计要求。     

高温气冷堆回热循环及透平机组的初步研究

结合了模块式高温气冷堆与气体透平循环技术的高温堆气体透平循环是核电领域中的全新概念，为提高核电的安全性和经济性提供了新的思路，具有很强的竞争优势。其中，高温气冷堆回热循环是该方案的主流。在高温堆回热循环方案中，氦气透平机组的工作介质为氦气，其物性与空气有很大的不同，因此，氦气透平与燃气透平在热力参数、气动参数、尺寸、级数等方面有着较大的差别。本研究对回热循环以及氦气透平进行了初步分析，并通过与燃气透平的比较，揭示了回热循环与氦气透平的一些基本设计特点。     

HTR-10氦气流中石墨颗粒尺寸的估计

清华大学10MW高温气冷堆（HTR-10）采用石墨结构材料和石墨燃料元件，以及氦气冷却剂。由于结构部件的摩擦和磨损，反应堆一回路氦气流动中不可避免的带有石墨粉尘，这是反应堆设计中必须加以考虑的重要问题之一。本文根据凝并理论和颗粒学中的离散-分区模型（Discrete-Sectional Model,DSM），建立了一种颗粒成长的计算方法，并对其进行了验证；同时运用该方法研究了HTR-10氦气流中石墨颗粒的发展情况，给出了氦气流中石墨颗粒在反应堆正常运行时的尺寸分布，并计算出石墨颗粒直径主要分布于10～20um，平均直径为12.9um。     

HTR-10主氦风机腔室内核素沉积的计算

分析了SPATRA程序的物理模型和适用参数,给出了主氦风机上腔室沉积计算的方法,并利用沉积吸附的4层计算模型对上腔室主要核素的沉积情况进行了保守性预测.以两个重要核素137Cs和131I为例说明了沉积计算的结果.预测结果表明,主氦风机的核素沉积现象并不严重,经过简单防护就可以进行更换作业.     

HTR-10氦循环风机远距离控制系统的设计

简要描述了清华大学10MW高温气冷实验堆的氦循环风机远距离控制系统的设计与调试概况 ,该系统的设计,基于反应堆主控制室的全数字化仪控系统以HS2000系统为组态平台和运行控制平台,全部操作实现了软操化。     

氦气试验回路中的氦净化

为了减少结构材料的腐蚀并验证高温气冷实验堆中的氦净化工艺，在氦气试验回路中设置了氦净化系统并进行了试验。试验结果表明，净化流量为５０ｍ＾３／ｈ的主要由分子筛和深活性炭床组成的氦净化系统，能把氦中２００００ｃｍ＾３／ｍ＾３的化学杂质净化到７６ｃｍ＾３／ｍ＾３以下。所采用的氦中痕量杂质分析测量技术达到１０＾－１ｃｍ＾３／ｍ＾３精度。     

高负荷氦气压气机的气体流动特点与改型设计

从氦气工质的特点入手,分析了氦气压气机设计参数选取区别于以空气为工质的压气机的特殊之处,重点分析了提高氦气压气机负荷的参数选择特点.由于氦气热物性与空气差别较大,气流经过压气机时的马赫数通常较低,造成单级压比较低,所以,氦气压气机的通流尺寸通常变化较小.为了提高单级负荷,减少压气机级数,需提高各级反动度.本文以多级氦气压气机为例,通过数值模拟分析了该压气机的三维流动特点,并进行了改型设计.     

The operational results of the KSTAR PF cryo-circuit

The Koreas Superconducting Tokamak Advanced Research (KSTAR) PF cryo-circuit is designed for cooling the fourteen superconducting magnets (Nb3Sn, NbTi) and structures. Those are cooled down by the supercritical helium (4.5 K and 5.5 bar) of a forced flow (pressure gradient: 2 bar) in order to maintain the supercritical state of the helium. To supply a large amount of supercritical helium (>370 g/s), a circulator was inserted into the PF cryo-circuit. The compressed supercritical helium is distributed to five helium manifolds with cryogenic valves and supplied to each PF magnet. While the PF magnets had been operating, the mass flow rate reduced and the pressure head of the circulator was fluctuated depending on the PF magnet operation scenario. These phenomena could damage the circulator and could stop it during operation. Therefore, by-pass valve, which is parallel with in-line valve and is connected with inlet and outlet of the magnet, was opened in order to reduce of the circulator's pressure head. In this paper, we focused on the helium behavior of the superconducting magnet when the by-pass valve was opened in order to release the pressure head of the circulator and the results will be presented.     

HTR-10氦风机磁悬浮转子跌落在辅助轴承上的数值分析

辅助轴承是10 MW高温气冷堆(HTR-10)氦风机磁力轴承-转子系统中的辅助支承结构,其主要任务是在磁力轴承因失电而失效时支承高速转动的转子,是整个系统安全运行的保证。本研究以HTR-10磁力轴承氦风机实验台架中的辅助轴承为研究对象,使用ABAQUS有限元软件数值模拟转子跌落,分析滚动辅助轴承内圈与滚动体的变形及能量损耗特性,并与初步的实验结果进行比对,验证辅助轴承的可靠性,为磁力轴承在高温气冷堆核电厂中的应用提供重要的技术保障。     

Primary System Aerodynamic Characteristics and Associated Circulator Operational Performance of HTR-10

The 10 MW high temperature gas-cooled reactor (HTR-10) has reached its first criticality in 2000 and is currently under testing for full power operation in the near future. The helium circulator test was carried out on both air and helium conditions with the same gas densities of 2.74 kg/m³ to measure the aerodynamic characteristics of the primary system and the operation performance of the circulator. This paper describes the test procedures and then analyzes the test results. Based on the test data, the aerodynamic characteristics of the primary system and associated operation performance of the circulator under real working condition of the HTR-10 are predicted. As a result, the helium circulator performance satisfies the aerodynamic and operational requirements of the HTR-10 primary system on real working condition by a considerable margin.     

Helium diffusion behavior and its retention in LaNiAl alloy from molecular dynamic simulations

Molecular dynamic method has been used to investigate the diffusion behavior of helium atom in the LaNiAl alloy system. The results have shown that diffusion coefficient of helium atom increases as the temperature increases from 300 to 1500 K, which indicates that helium atom gets more active via thermal desorption. The diffusion coefficient in LaNi₅ and LaNi₄Al are about 1.5 × 10⁻⁵ and 1.1 × 10⁻⁶ cm²/s at 1300 K, respectively, and the diffusion barrier of He are 1.45 and 0.52 eV, respectively. The helium diffusion is shown to be enhanced with temperature increasing. Compared with metallic La, Ni, Al and Pd, the simulation result implies that helium atom is more stable and difficult to diffuse in LaNi₅ and LaNi₄Al alloys, which are the most promising materials for helium retention in experiments. Our results indicate the correlation between diffusion behavior of helium atom and capacity of materials for helium retention. Therefore, it can be considered as a feasible method to evaluate the helium retention capacity of materials via determining the diffusion properties of interstitial helium atom.     

The fort st. vrain high temperature gas-cooled reactor III. Helium circulator auxiliaries

The helium circulator auxiliary system provides buffer helium and bearing water for the reactor's four circulators with two nearly identical auxiliary loops serving the two circulators of a primary coolant loop. A series of drains removes the water and helium for separation and recycle. Loss of buffer helium's function as a dynamic seal has resulted in inleakage of bearing water into the primary coolant and outleakage of primary coolant into the auxiliary system. Inleakage of water also has occurred due to inadvertent pressurization of the bearing cavity with the static shutdown seal set. Satisfactory performance of the normal, backup and emergency bearing water systems has been accomplished after numerous component additions and modifications. Frequent circulator trips have occurred. Most of these have involved the delicate sensors that measure buffer helium differential pressure. Transients in one loop have communicated to the other loop through common components. Total separation of the auxiliary loops will occur after the planned installation of those components that currently service both loops.