HTR-10一回路放射性石墨粉尘实验系统设计及研究

在10MW高温气冷堆(HTR-10)氦净化系统中,设计并建造了用于取样收集一回路放射性石墨粉尘的实验系统。结合国外已有的研究结果,根据HTR-10氦净化系统的运行参数进行了模拟计算。计算结果表明,该实验系统能有效过滤收集到的放射性石墨粉尘。所设计的取样过滤器便于拆卸和后期测量,可实现对放射性石墨粉尘进行长期系统的研究,给出反应堆不同运行工况下一回路氦净化系统中石墨粉尘及固体裂变核素活度的信息,将为HTR-10高温气冷堆裂变产物行为研究提供大量重要的实验研究数据。     

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。     

钠冷快堆一回路主循环泵在厂外主辅电源切换工况下的运行特性研究

在厂外主辅电源切换时,为避免因一回路主循环泵（简称主泵）运行引起反应堆保护停堆或电机辅助绕组启动,对主泵惰转特性及转速控制进行分析,分别对快切和慢切工况下主泵的快速飞车启动和搜频飞车启动模式进行研究,给出了不同模式下主泵的最低转速预测模型,分析出了快切工况（断电1.5 s）下主泵最低转速为708.3 r/min,慢切工况（断电10 s）下最低转速为341.2 r/min。在主泵水台架上,用1.5 s和10 s断电试验来模拟厂外主辅电源快切和慢切工况,试验结果表明,快切工况下主泵最低转速为689r/min;慢切工况下主泵最低转速为346.7 r/min。最低转速预测值与试验值吻合较好,偏差小于3%。试验验证了主泵在主辅电源切换工况下的运行特性,可实现快切不导致反应堆保护停堆,慢切不导致辅助绕组启动,对反应堆安全运行具有指导意义。     

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。     

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。     

高温气冷堆核电站安全级湿度仪研制

华能石岛湾高温气冷堆核电站与现役压水堆核电站一回路冷却剂不同,其采用氦气做为一回路冷却剂。氦气中水分含量过高可能导致安全事故,在运行时需要实时监控一回路冷却剂中的水分含量,当水分含量超过限值时发出停堆信号传送到保护系统。高温气冷堆湿度仪工作在高压环境下,输出信号与温度、湿度、压力等有关。通过试验压力、温度、湿度等物理量对湿度传感器输出信号的影响的分析研究,建立水分含量补偿模型,研制出基于纯硬件补偿电路的湿度仪样机并通过1E级鉴定试验验证。1E级湿度仪实现了实时监控一回路冷却剂中的水分含量,在水分含量超过限值时触发保护系统实现保护逻辑的目标,为反应堆安全运行提供了技术保障。     

核电厂一回路系统模拟实验设计与分析

研究核电站特定运行工况下,一回路系统传热流动的规律。应用Ishii模化方法模拟压水堆核电厂的一回路系统,设计出主泵与关联系统耦合实验回路的主要热工参数。同时,应用机理性程序对设计的实验回路进行分析。结果表明,基于Ishii模化方法设计的实验回路主要参数合理可行;模型可以研究反应堆原型事故运行瞬态工况下,一回路各系统间传热流动相互影响规律。     

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.     

主循环泵瞬态特性计算

1 前言 一回路主循环泵的设计和制造,对核电站的运行和安全将起着十分关键的作用。只有在一回路主循环泵工作可靠的情况下,核电站连续地正常供电才有保证。在事故工况下,主循环泵还起着阻止事故扩大的作用。 全厂断电时,主循环泵失去电源而惰转,通过堆芯的冷却流量突然减少,给堆芯元件的安全带来威胁。因此,在设计压水堆核电站时,要求主循环泵具有较长的惰转时间,以便确保全厂断电后堆芯安全。     

The experimental study on the helium circulator of HTR-10

The helium circulator is a key component of 10 MW high temperature gas-cooled reactor (HTR-10), which has the helium coolant circulate inside the primary loop of the reactor. Before delivery, the performance experiment of the circulator was carried out in the factory at 0.426 MPa, 250 °C nitrogen condition. In the paper, by using dimensional methodology, the experiment results are converted to those on 3.0 MPa, 250 °C helium condition which is real working condition on the reactor. Then the circulator performances are analyzed. Finally, the operating performances on HTR-10 are predicted. The paper concludes that the circulator design was made correctly and the performances are satisfied with HTR-10 operating requirements.     

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.     

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。     

Post-test analysis of helium circulator trip without scram at 3 MW power level on the HTR-10

Safety demonstration tests were conducted on the 10 MW High Temperature Gas-cooled Reactor-Test Module (HTR-10) to verify the inherent safety characteristics of modular High Temperature Gas-cooled Reactors (HTGRs) as well as to obtain the transient data of reactor core and primary cooling system for validation of HTGR safety analysis models and codes. As one of these safety demonstration tests, a simulated anticipated transient without scram (ATWS) test called loss of forced cooling by tripping the helium circulator without reactor scram was carried out at 3 MW power level on October 15, 2003. This paper simulates and analyzes the power transient and the thermal response of the reactor during the test by using the THERMIX code. The analytical results are compared with the test data for validation of the code.Owing to the negative temperature coefficient of reactivity, the reactor undergoes a self-shut down after the stop of the helium circulator; the subsequent phenomena such as the recriticality and power oscillations are also studied. During the test a natural circulation loop of helium is established in the core and the other coolant channels and its consequent thermal response such as the temperature redistribution is investigated. In addition, temperatures of the measuring points in the reactor internals are calculated and compared with the measured values. Satisfactory agreements obtained from the comparison demonstrate the basic applicability and reasonability of the THERMIX code for simulating and analyzing the helium circulator trip ATWS test. With respect to the safety features of the HTR-10, it is of most importance that the maximum fuel center temperature during the test is always lower than 1600 °C which is the limited value for the HTGR.     

Research program and test loop for the prototype of a HTR coolant gas circulator with magnetic bearings “MALVE”

For its high-temperature reactor line ABB has completed the development of a coolant gas circulator with magnetic bearings which is now ready for production. The construction of a full scale prototype has been started. With a power input of 400 kW, a rotor with magnetic bearings weighing 2 tons, and an overhung impeller of 1.25 m diameter the circulator exhibits features which might be of interest for the conventional compressor business as well.While the manufacture of the circulator is in progress a test loop will be erected. Tests in air/nitrogen and helium atmospheres are planned. The purpose of the tests is above all to verify the dynamic behaviour of the circulator at different speeds, temperatures, and gas densities. Features of the nature of the tests and of the test loop as well as the milestones of the test program will be described.     

氦气杂质对中间换热器材料的影响初探

中间换热器是高温气冷堆氦气透平间接循环和高温工艺热应用的关键部件.中间换热器属于一回路压力边界,它将堆芯出口温度达900～1 000 ℃氦气的热量传递给二回路氦气,此外还承受一、二回路氦气压差,因此,目前能够用于中间换热器的耐热金属材料非常有限.高温气冷堆一、二回路氦气中含有H_2、H_2O、CO、CH_4等杂质,在高温下,氦气杂质对中间换热器材料的影响主要是氧化、碳化和脱碳,降低材料的机械性能,其影响不可忽视.对于中间换热器设计,现有规范的温度范围需扩展,氦气杂质对材料强度的影响也需考虑.     

The Fort St. Vrain high temperature gas-cooled reactor: II. Helium circulators

In field tests in a fossil-fueled facility, performed concurrently with Fort St. Vrain's construction, data indicated that the helium circulator design was well suited to provide primary coolant circulation for the high temperature gas-cooled reactor. After plant installation, primarily during the hot functional tests, a number of time-consuming delays developed caused by cavitation damage on circulator speed valves, cavitation and fatigue damage on auxiliary water turbine buckets, water turbine nozzle erosion, static shutdown seal cracks and circulator primary closure helium leakage. After extensive analysis and testing, all of these problems were corrected. Circulators have performed satisfactorily at levels up to 70% of rated power.     

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.     

Simulation Study of AVR-U Nuclear Process Heat Plant

A pebble-bed high temperature gas-cooled reactor AVR located at Jülich, West Germany has a modification plan to include a process heat loop. In the plan, half of the primary helium heated up to 950°C by the AVR core is supplied to the process heat loop. The helium flow of the process heat loop influences the flow of the AVR loop and vice versa. Consequently, flow instabilities and reverse flow in the modified plant may possibly happen.

In the paper, a computer simulation is performed to investigate the dynamic behavior of the primary helium flow in the modified plant. At first, dynamic experiments conducted at the AVR plant are simulated in order to grasp the accuracy of the computer code. Then, the modified plant is simulated. As a result, the behavior of the primary flow is rather moderate against the disturbances which are expected under the normal plant operation. Further, the condition when the reverse flow appears is evaluated analytically by using a simplified flow network model.