飞机压力加油冲击压力周期及采样率选择分析

燃油系统管路阀门的开关是引起冲击压力出现的常见因素之一,而冲击压力的出现则可能导致管路或阀门的破坏。在飞机鉴定或民航取证过程中,需要测量冲击压力,它是非稳态参数,变化频率快,采样率选取不合适则可能导致测量失败。本文对飞机压力加油过程中冲击压力的数据进行了统计,然后对冲击压力脉动周期的影响因素,各段管路对周期大小的贡献和冲击压力采样率的选取原则进行了分析。分析表明周期的大小主要取决于管路材料的物性参数及几何尺寸,而加油软管段是影响周期大小的主要因素,采样率应选择为周期大小10倍为宜。     

飞机液压油和滑油压力加油装置的研制

针对目前给飞机添加液压油和滑油时存在的一些弊端,根据可靠性理论和液体压强传递的原理,设计一种新型的多功能压力加油装置,并介绍了加油装置的组成、工作原理、性能特点以及应用情况。     

Understanding the design and economics of distributed tri-generation systems for home and neighborhood refueling—Part I: Single family residence case studies

The potential benefits of hydrogen as a transportation fuel will not be achieved until hydrogen vehicles capture a substantial market share. However, although hydrogen fuel cell vehicle (FCV) technology has been making rapid progress, the lack of a hydrogen infrastructure remains a major barrier for FCV adoption and commercialization. The high cost of building an extensive hydrogen station network and the foreseeable low utilization in the near term discourages private investment. Based on the past experience of fuel infrastructure development for motor vehicles, innovative, distributed, small-volume hydrogen refueling methods may be required to refuel FCVs in the near term. Among small-volume refueling methods, home and neighborhood tri-generation systems (systems that produce electricity and heat for buildings, as well as hydrogen for vehicles) stand out because the technology is available and has potential to alleviate consumer's fuel availability concerns. In addition, it has features attractive to consumers such as convenience and security to refuel at home or in their neighborhood.The objective of this paper is to provide analytical tools for various stakeholders such as policy makers, manufacturers and consumers, to evaluate the design and the technical, economic, and environmental performances of tri-generation systems for home and neighborhood refueling. An interdisciplinary framework and an engineering/economic model is developed and applied to assess home tri-generation systems for single family residences (case studies on neighborhood systems will be provided in a later paper). Major tasks include modeling yearly system operation, exploring the optimal size of a system, estimating the cost of electricity, heat and hydrogen, and system CO₂ emissions, and comparing the results to alternatives. Sensitivity analysis is conducted, and the potential impacts of uncertainties in energy prices, capital cost reduction (or increase), government incentives and environmental cost are evaluated. Policy implications of the modeling results are also explored.     

Optimization of Refueling Scheme of Sodium-Cooled Fast Reactor Core Using Heuristic Enumeration Method

Abstract

Basic considerations are discussed in the area of LMFBR refueling optimization. The procedure of search for the optimum refueling scheme is based on a systematic enumeration algorithm embodying the heuristic rule “Elimination of Hopeless End States (EHES)”. The optimization procedure thus developed reveals the global characteristics of the refueling scheme, on the basis of a macroscopic regression model which describes the burnup-dependent core performance.

Sample numerical results are obtained on problems of optimizing the refueling scheme for the 4-zone zone-loaded and 2-zone scatter-loaded cores of a typical sodium cooled mixed-oxide fueled fast power reactor. Case studies are conducted on the effect of change in the elimination factor adopted in applying the EHES, in the upper or lower boundaries of constraints, in the performance criterion, and in various parameters governing the mode of reactor operation such as the duration of one cycle period. The study has revealed several notable characteristics particular to LMFBR core refueling, such as the common trait of optimized refueling schemes for 2-region cores of repeated identical refueling patterns, and incompatibility between radial power flattening and sustained useful life for the core.     

Conceptual Design of a Modular Island Core Fast Breeder Reactor “RAPID-M”

A metal fueled modular island core sodium cooled fast breeder reactor concept RAPID-M to improve reactor performance and proliferation resistance and to accommodate various power requirements has been demonstrated. The essential feature of the RAPID-M concept is that the reactor core consists of integrated fuel assemblies (IFAs) instead of conventional fuel subassemblies. The RAPID concept enables quick and simplified refueling by replacing IFAs in which all the core and blanket fuel elements are comprised. In this paper, the 600 MWe RAPID-M design consists of 7 IFAs is presented. Significant reactor mass savings and the improvement of inherent safety features are discussed. Plant dynamics analyses using the multi-point reactor kinetics equations to accommodate the modular core configuration demonstrated a favorable transient response in case of unprotected transient over power (UTOP).     

中国实验快堆换料系统的验证试验

介绍了中国实验快堆换料系统的验证试验。该试验以检查设备的性能、验证系统的工艺要求和验证换料监控系统为目的,为此建立了综合试验台架,并在台架上首次模拟实现了快堆换料系统的全自动换料操作,为即将开始的中国实验快堆的安装调试奠定了坚实的基础。     

在轨维修后端模块接口机构的研究

在轨维修可以大大的延长空间科学仪器的使用寿命,节省大量的经济成本。为了实现空间望远镜后端模块的在轨操作和更换,设计了一套与之对应的接口机构,能够解决在轨快速定位与安装。根据321运动学定位准则,详细介绍了该接口机构的内部组成和工作原理;然后把该接口机构与后端模块进行组件级有限元仿真,仿真结果表明一阶模态远高于整机基频可以有效地避免发射时候的共振;设计了一套平面内的工装来模拟后端模块,利用等效质量法对整个机构进行重力卸载;搭建实验平台,利用激光跟踪仪来测量整个后端模块的重复定位安装精度,实验数据表明,X,Y,Z 3个方向的重复平移定位误差分别为±5.58μm,±3.24μm及±3.63μm,优于总体指标±10μm;热实验结果表明整个机构可以完全释放由于温度变化产生的形变,具有很高的热稳定性;使入射光线和靶面的相对位置持续稳定,保证了较高的成像质量。为其他空间在轨维护装置提供强有力的参考价值。     

CNG橇装压缩机组关键系统的设计

对CNG加气站内橇装压缩机组的几个关键系统进行了研究,并对系统的选型与设计提出了建议。     

热控涂层性能在轨测试用辐射计原理样机的设计与仿真

为验证热控涂层性能退化地面模拟试验的有效性,提出了一种利用测热法实现热控涂层在轨测试的辐射计原理样机设计方案.通过对在轨辐射计所接收的外热流进行分析,应用能量守恒原理建立了其测试热控涂层太阳吸收率的数学模型,并在该测试模型的基础上设计辐射计的测热和隔热结构.利用ANSYS软件对辐射计结构的关键组成部分进行了热仿真,并在恒温测试环境下利用辐射计对SR107热控涂层进行了原理验证试验,试验测得的SR107热控涂层太阳吸收率值与该涂层的标定值差别在3%以内,通过分析计算辐射计具有4.2%的测试不确定度.仿真和试验结果表明:辐射计原理样机的设计满足热控涂层性能在轨测试的要求.     

基于干扰观测器的无人机在轨姿态控制系统设计

针对无人机在轨姿态控制系统误差较大的问题,提出基于干扰观测器的无人机在轨姿态控制系统设计.选择 STK５３F４０６V 作为微处理器的芯片,存储器选用 AY５４GN１７８M 芯片,通过 TIM 时钟输入捕获命令进行脉冲调制信号的采集与存储.系统软件采用干扰观测器来分析无人机姿态控制中的干扰频域,从干扰的种类、精度、动态性能和飞行模式等方面对系统进行正弦波的干扰分析,将扰动与系统的控制参数控制在同一个范围内,实现对飞行状态的修正和扰动频率的正确估计.实验结果表明,基于干扰观测器的无人机姿态控制系统的抗干扰性强,耗时较短,控制性能较好.