空间核反应堆安全分析

空间核反应堆是空间能源的重要候选方案,其寿命长、功率大、结构紧凑,但其特有的中子学特性、与传统快堆迥异的设计方案对堆芯安全分析提出了挑战。本文以热管型空间堆为例,首先基于蒙特卡洛方法对空间堆在水淹和沙埋事故工况下,进行了稳态中子学计算分析,结果表明:堆芯在事故工况下不会重返临界。同时,基于瞬态多物理分析程序TMACS,进行了单根控制鼓旋转瞬态过程计算。结果表明:空间堆在热工反馈和热膨胀反馈的多物理耦合下,在特定的瞬态过程中能够保持功率稳定,满足安全要求。     

Optimisation of powerful energy supply systems for application in space

In this paper it is shown how a nuclear power system with turboelectric conversion is being optimised for application in space and how data subject to the mission and technological data enter into such an analysis. Thereafter it follows a comparison with nuclear power systems with magnetofluiddynamic and thermionic converters.     

Recent advances in lunar base simulation

This article reports about the results of the latest computer runs of a lunar base simulation model. The lunar base consists of 20 facilities for lunar mining, processing and fabrication. The infrastructure includes solar and nuclear power plants, a central workshop, habitat and farm. Lunar products can be used for construction of solar power systems (SPS) or other spacecraft at several space locations. The simulation model evaluates the mass, energy and manpower flows between the elements of the system as well as system cost and cost of products on an annual basis for a given operational period. The 1983 standard model run over a fifty-years life cycle (beginning about the year 2000) was accomplished for a mean annual production volume of 78 180 Mg of hardware products for export resulting in average specific manufacturing cost of 8.4 $/kg and total annual cost of 1.25 billion dollars during the life cycle. The reference space transportation system uses LOX/LH₂ propulsion for which at the average 210 500 Mg LOX per year is produced on the moon. The sensitivity analysis indicates the importance of bootstrapping as well as the influence of market size, space transportation cost and specific resources demand on the mean lunar manufacturing cost. The option using lunar resources turns out to be quite attractive from the economical viewpoint. Systems analysis by this lunar base model and further trade-offs will be a useful tool to confirm this.     

兆瓦级探月火箭空间核电源系统设计与性能研究

针对目前空间核电源在深空探测领域功率不足的问题，结合热离子热电转换空间核电源和碱金属热电转换空间核电源的发电方式，提出一种新型空间核电源。计算堆芯有效增殖因子、功率峰值因子、冷却剂空泡系数和停堆深度等安全性参数，并通过分析接收极功函数和碱金属热电转换系统电流密度等性能参数。之后，对比耦合发电系统与原热离子热电转换空间核电源和碱金属热电转换空间核电源的效率，发现新型耦合发电系统发电效率分别较另两种发电系统提高约6％和约10％。最后建立动态模型进行分析，确保核电源可以稳定运行，为大功率核电源设计提供理论依据。     

Net electric power of concentrating solar mirror systems for application in space as a function of the distance to the sun

The use of solar radiation by means of concentrating solar mirror systems, such as parabolic and spheric configurations, mainly is an engineering problem. A decisive characteristic for the optimisation of a complete system with turboelectric power conversion is the thermal cycle applied. Besides the Carnot process, here taken up into the study as an ideal comparative process, suitable processes for the technological realisation are the Brayton process and the Rankine process. The Brayton process is a typical gas turbine process using only the gaseous phase. The Rankine process is a steam engine process using liquid and gaseous phase.The work in hand shows how such solar systems with turboelectric conversion are optimised with respect to their specific weight (kg/kW_e) and how the distance to the sun as well as technological data enter into the analysis.As expected, the Carnot cycle as an ideal comparative process for both types of systems shows the best results for the optimum specific mass of the system. Regarding the real processes, the Rankine cycle shows more favourable characteristics than the Brayton cycle. The difference of the specific masses of the real processes mainly results from the different thermal conditions at the radiator.The influence of the distance to the sun is as expected. The nearer to the sun the solar power system operates, the better is the optimum specific mass of the system. For distances to the sun between 0.3 and 1.0 AU the spheric system shows a better behaviour than the parabolic system. For distances to the sun greater than 2.0 AU the parabolic system shows better behaviour of the specific weight. In the region between 1 and 2 AU the better optimum specific mass of the system belongs to the technological data used in the analysis.     

100 kWe级空间快堆核电源系统仿真平台开发与应用

空间核反应堆电源作为一种具有竞争力的空间电源方案,正逐渐受到关注及应用。本文针对一个100 kWe级锂冷快堆耦合布雷顿循环的空间堆核动力系统方案,修改了RELAP5程序中的物性程序、换热模型,程序中的中子动力学模块使用蒙特卡洛方法计算快堆物理参数与堆芯控制调节参数,由此集成并建立一个空间快堆核动力系统综合仿真平台,应用该平台对100 kWe级空间堆核动力系统进行了稳态模拟与事故分析。结果表明:在瞬态发生后系统各参数变化符合预期,验证了各部件及控制系统的功能性及有效性;同时,还初步进行了仿真平台用于100 kWe级空间反应堆核动力系统设备的设计优化的实践,为空间快堆设计与安全分析提供了技术储备。     

Structured methods for identifying and correcting potential human errors in space operations

Human performance plays a significant role in the development and operation of any complex system, and human errors are significant contributors to degraded performance, incidents, and accidents for technologies as diverse as medical systems, commercial aircraft, offshore oil platforms, nuclear power plants, and space systems. To date, serious accidents attributed to human error have fortunately been rare in space operations. However, as flight rates go up and the duration of space missions increases, the accident rate could increase unless proactive action is taken to identity and correct potential human errors in space operations. The Idaho National Engineering and Environmental Laboratory (INEEL) has developed and applied structured methods of human error analysis to identify potential human errors, assess their effects on system performance, and develop strategies to prevent the errors or mitigate their consequences. These methods are being applied in NASA-sponsored programs to the domain of commercial aviation, focusing on airplane maintenance and air traffic management. The application of human error analysis to space operations could contribute to minimize the risks associated with human error in the design and operation of future space systems.     

Nuclear space—an indispensable option?

There is renewed interest in using nuclear power in a variety of ways in space, as well as in disposing of terrestrial nuclear waste aloft. While the benefits of such use to space exploration might be high, the potential costs to Earth and its inhabitants are currently too dear. Accidents have already occurred which, despite official denials, have spread radiation worldwide. Such denials are characteristic of the closed and secretive nature of the nuclear ‘debate’. This viewpoint calls for the involvement of all those concerned with space nuclear power—lay, professional, government and NGO—in decisions on whether to proceed with it and suggests that maybe we should wait for safer scientific discoveries before we attempt further planetary exploration.     

空间核电源电力系统功率因数校正技术的研究

为满足我国未来深空探测、星表基地等空间任务电源系统的需求,通过采用基于空间核电源系统的功率因数校正技术来滤除和抑制由发电机产生的谐波,从而提高系统的用电效率。提出一种新型Boost PFC拓扑结构,首先分析变换器的工作原理,之后对工作在连续电流导通模式下的Boost变换器进行建模分析。通过对变换器双环控制中的电压环和电流环进行理论设计和数学推导,从而确定控制环路参数。采用PLECS仿真软件对变换器的控制策略和系统的动态响应进行验证,并实现输入电流对输入电压的零相位正弦化追踪。     

空间核反应堆电源研究进展

随着航空航天领域对能源需求的不断扩大,核能的空间应用迎来了新的发展高潮。本文针对空间核反应堆技术的发展现状进行综述,重点关注了空间核反应堆与静态能量转换、动态能量转换技术结合供电的研究进展,总结分析了空间核反应堆电源技术的发展特点,并指出未来发展中需要重点关注的内容,为未来空间核反应堆电源的发展提供指导。     

空间核动力平台电力管理系统的设计

空间核动力平台是一种全新的电源推进一体化航天器,其电力系统具有三相交流输出、工况多且复杂、母线电压体制多等特点。为了解决空间核动力平台负载供电诸多难题,通过对系统功能、负载类型、母线体制、组成配置、工作模式、控制机制等方面论证分析,提出了一种新型空间核动力平台电力管理系统架构。其中,变配电系统从硬件实现角度解决了基于布雷顿热电转换系统输出为负载稳态供电问题,自主控制系统从软件控制角度解决了主能源、辅助能源等多能源间流动控制以及负载暂态匹配问题,这为未来空间核动力平台电力管理系统研究工作奠定了基础。     

分子污染对卫星太阳电池翼输出功率的衰减研究

分子污染是引起卫星太阳电池翼输出功率衰减的因素之一。用直接模拟蒙特卡罗（Direct Simulation Monte Carlo）方法分析了空间分子污染物的传输过程，采用十组不同的输入参数计算了在轨运行期间分子污染物在某型号卫星太阳电池翼表面的沉积膜厚度，分析了太阳电池翼输出功率的衰减情况。     

基于氢化镁的核电/核热双模共质空间核动力技术

针对未来空间任务对能源和动力日益提高的需求,提出了基于氢化镁的核电核热双模共质空间核动力技术。该技术以一种储氢密度高、热稳定性较好,能够以常温常压储存的氢化镁作为工质,通过核能加热后氢化镁分解成为核热推进可用的高压氢气和电推进可用的单质镁,并结合高效动态热电转换系统,形成大功率核电源、大功率超高比冲核电推进、高比冲氢气核热推进以及大推力镁核热推进多种工作模式。基于氢化镁的多模共质空间核动力技术解决了低温推进剂、气态工质在空间应用时的存储安全性和存储密度低的问题,其具备的多种工作模式能够针对不同任务需求提供相应的能源或者动力输出,提高核动力飞行器任务能力。     

Strategies of developing advanced lunar power systems

Electric and thermal power have to be available at the base site on the lunar surface before the first lunar crew arrives. Unlimited solar energy is available during the lunar day, but this must be stored for use during the lunar night unless nuclear energy systems are available. State-of-the-art candidate systems are reviewed and the production of solar cells on the moon is discussed. Various options for developing a lunar power plant are proposed. These must be simulated and optimized in a real lifecycle systems scenario to provide operations and cost data essential for choosing a strategy.     

Strategies of developing advanced lunar power systems

Electric and thermal power have to be available at the base site on the lunar surface before the first lunar crew arrives. Unlimited solar energy is available during the lunar day, but this must be stored for use during the lunar night unless nuclear energy systems are available. State-of-the-art candidate systems are reviewed and the production of solar cells on the moon is discussed. Various options for developing a lunar power plant are proposed. These must be simulated and optimized in a real life-cycle systems scenario to provide operations and cost data essential for choosing a strategy.     

Societal imperatives and the need for space nuclear power and propulsion systems

The development and exploitation of nuclear power and propulsion represent certain didactic imperatives for human civilization. Among these are economic, epistemological, moral and commercial propositions. Developing space nuclear power and propulsion represents one future; the choice of not to pursue the course barring some breakthrough in physics represents a dramatically different future. The author argues that the time is now fortuitous for deployment and operation of nuclear propulsion and power, primarily nuclear electric propulsion, at significant levels, employing figures of merit that transcend simple cost models used to justify nuclear power sources in the past. The proposition is examined, in the light of US and UN restrictions, to ascertain how best to proceed. The author argues that viewpoints of certain vocal albeit uninformed public interest groups are typically self-serving and generally categorically incorrect; it can be asserted that these same groups do not truly represent the public interest at all. It is, therefore, necessary to present an even-handed assessment of both sides of the argument to determine the virtues and liabilities of embarking on such a developmental path. Given the imperatives mentioned, the author argues that nuclear power and propulsion for space systems is a societal necessity.     

大型空间电站在轨展开与组装动力学与控制

针对大型空间电站在轨展开与组装过程中复杂的动力学环境,将桁架类大型空间电站视为一个刚柔多体系统,采用自然坐标法对刚性构件建模,基于绝对节点坐标方法描述柔性桁架结构,编写了一套动力学仿真软件,实现了大型空间电站在轨展开与组装动力学的精确仿真.仿真结果表明,采用摆线运动插值函数作为控制方程有利于提高多级展开过程的稳定性;在...     

地磁扰动期间低轨目标轨道预报的误差修正

针对地磁扰动期间大气密度变化造成的低轨目标较大的轨道预报误差,提出一种根据POES卫星观测的极光能量注入数据改进短期轨道预报的方法。分析表明CHAMP卫星的沿迹大气密度及轨道衰减与极光能量注入具有较好的相关性。通过线性回归方法,建立轨道半长轴衰减及阻力调制系数的修正公式,并使用修正后的阻力调制系数取代两行元(TLE)中的该系数带入SGP4模型进行位置预报。该方案考虑了外推过程中地磁扰动引起的大气密度响应,能更准确地反映外推过程中大气阻力对轨道的影响。将其应用到2008年CHAMP卫星和国际空间站的轨道预报中,结果表明,半长轴和位置的预报误差可分别降低50%和30%左右。进一步对不同年份、不同轨道高度的目标进行了预报误差修正的分析,验证了该方法的普适性。     

液氧加注过程热力性能分析

为满足某型号运载火箭动力系统试验液氧加注温度要求,需对加注过程进行热力性能分析。通过对常规氧加注过程因漏热和流阻损失引起的温升、液氧泵效率损失引起的温升进行理论计算,得出常规氧加注过程液氧温度变化规律。此外,通过对过冷氧温度掺混特性进行理论计算和数值仿真,得出过冷氧加注的热力性能。上述分析结果与实测数据进行了比对,结果表明,理论分析结果与实测结果吻合性好,液氧加注过程热力特性分析方法正确可行。     

小卫星太阳电池阵结构声振响应分析研究

针对高频段太阳电池阵结构声振问题求解中的结构模态参数不确定性,文章从统计模态和能量平衡的角度出发,深入研究了复合材料面板太阳电池阵夹层结构的统计能量分析参数确定及功率流模型创建方法,并快速得到了太阳电池夹层结构的声振响应。对比分析与试验结果,发现二者吻合很好,因而验证了该声振响应分析方法用于小卫星太阳电池阵结构的有效性,并可作为小卫星工程研制中太阳电池阵结构动力学分析的有益补充。