Dynamic analysis of the NPP pressure sensor system

The aim of the work was to develop on-line methods of control and diagnostics of pressure sensors at a NPP. The analysis was carried out along two lines:

1. i) The detection system including the sensor itself was modeled theoretically to obtain and study its transfer function, and to establish correspondence between the spectral characteristics of the pressure signal.

2. ii) The numerical processing of the signal using the AR technique to reconstruct the transfer function and evaluate the system's response, to a step impulse, as well as the spectral analysis. The hydraulic model presented indicate that the spectral lines observed at 10 Hz are due to longitu-dinal oscillations of water in the system branches, while the response time of the detection system is effectively the time of signal retardation in the porous ceramic diaphragms of the δ-cell of the sensor itself.

     

反应堆堆芯围筒结构热流固耦合热变形分析

针对反应堆堆芯围筒热流固耦合问题,采用三维有限元法研究堆芯围筒的热变形.考察ANSYS的三维实体热单元SOLID 70,三维实体单元SOLID 45,三维表面热效应单元SURF 152和三维热-流耦合管单元FLUID 116等单元类型的特点和实用性.建立堆芯围筒、吊篮和冷却剂的温度分析有限元模型：堆芯围筒和吊篮采用SOLID 70,结构表面与冷却剂的对流传热表面采用SURF152,堆芯围筒与吊篮之间冷却剂采用FLUID 116.采用SOLID 45建立堆芯围筒有限元模型,根据得到的堆芯围筒、吊篮和冷却剂的温度场结果分析堆芯围筒热变形.结果表明,在考虑堆芯围筒及吊篮固体和流体的交叉耦合的基础上,采用三维有限元法能比较客观地模拟反应堆堆芯处的复杂运行环境.     

面向高端装备制造CAE技术的机遇和挑战

针对高端装备制造在设计、分析、制造、服役和维护等全过程中对CAE的需求,从结构、流体以及流固耦合等3个方面概述CAE技术国内外进展及其面临的机遇和挑战,指出在发展具有能够对装备在极端服役环境下准确的结构、流体和流固耦合CAE分析技术的基础之上,需不断突破面向工程应用的多物理场耦合、跨尺度分析、多学科综合设计、产品性能评估和集成等关键技术,使CAE逐步向支持现代设计和全寿命周期管理转变.     

叶片数对超低比转速斜流式水轮机的影响

叶片数是影响超低比转速斜流式水轮机水力性能的因素之一。文章利用Fluent 16.0软件,研究分析了不同叶片数模型在不同流量工况下,外特性曲线以及内部流场分布图。结果表明:不同叶片数时,流量从最高效率点向小流量变化时效率下降的速度要比从最高效率点向大流量变化时的快。对于具体参数组合的超低比转速斜流式水轮机,存在最优的叶片数使得其水力性能最优。     

液压支架工作状态模糊识别系统研究

针对目前综采工作面液压支架压力监测系统只能监测综采工作面压力,不能对液压支架工作状态进行识别的问题,设计了一种液压支架工作状态模糊识别系统。该系统可对现有的综采工作面液压支架压力监测系统监测到的压力数据进行模糊识别,根据模糊识别输出值即可判断液压支架的5种工作状态,即降架、移架、升架、增阻、卸压保持;当液压支架处于增阻工作状态且增阻时间过长时,该系统可及时通知液压支架操作工增大液压支架压力,辅助实现顶煤破碎。测试结果验证了该系统的可行性。     

基于FPGA的开关量输入模块设计

在测控系统中,经常需要对各种现场信号进行采集;该模块主要实现对开关量状态信号进行实时监控,记录状态信息,为故障诊断提供依据;在设计中,采用了光耦隔离器件对输入信号进行了隔离和抗干扰处理,使用了FPGA实现了数据实时采集和中断处理,最后经PCI总线与主机进行数据交互;在故障诊断系统中,该信号采集板工作稳定、可靠,能够满足系统的实时性要求。     

Stability analysis and H∞ control for hybrid complex dynamical networks with coupling delays

This paper formulates and studies a model of complex dynamical networks with switching topology and coupling delays. Based on the hybrid control and Lyapunov function, the stability and robust H_∞ control of such networks with impulsive and switching effects, which have not been studied before, are addressed with some criteria derived. Examples are given to illustrate the effectiveness of the theoretical results. Copyright © 2011 John Wiley & Sons, Ltd.     

Floral volatiles ofTanacetum vulgare L. attractive toLobesia botrana den. et schiff. females

The European grapevine moth (EGVM),Lobesia botrana, is a major pest of grapes in Europe. Females are attracted to a nonhost plant: tansy (Tanacetum vulgare L.), which is a common weed in Slovakian vineyards. A steam distillate extract of tansy flowers was analyzed by means of a GC-EAG technique to screen constituents detected by the olfactory receptors of EGVM females. From more than 200 GC peaks, nine peaks corresponding to monoterpenoids released an EAG response in more than 70% of the females (N=15):p-cymene,d-limonene,-thujene,-thujone,-thujone, thujyl alcohol, terpinene-4-ol, (Z)-verbenol, and piperitone. The steam distillate of tansy as well as a synthetic blend of identified compounds released consistent attraction in a field cage. The use of nonhost plants and host plant odors in integrated pest management is discussed.     

四辊铝箔轧机预控参数在线整定

介绍Ф210mm/Ф500mm× 800mm四辊液压轧机厚度预控系统中采用人机界面实现参数在线调整的方法,能大大提高预控参数的控制精度,减少轧机产品的厚度误差,是厚度自动控制的一项创新.     

基于孔隙压力黏结单元的准脆性材料水力劈裂模拟

传统数值方法对水力劈裂的模拟一般采用预设裂缝扩展路径,且将水流作用等效为压力荷载,难以反映裂缝渗流-开裂耦合效应. 采用自编程Python脚本程序批量插入孔隙压力黏结单元,考虑裂缝渗流-开裂耦合作用模拟准脆性材料水力劈裂随机扩展全过程. 在对经典理论模型及试验结果模拟验证的基础上,开展含多裂缝均质模型的水力劈裂全过程分析,并进一步建立混凝土细观尺度水力劈裂模型,分析骨料、界面过渡区和基体渗透性对混凝土劈裂全过程的影响. 结果表明,本研究模型可以有效模拟准脆性材料水力劈裂失效过程,准脆性材料多缝开裂过程伴随微裂缝的分叉扩展而非光滑的裂缝扩展路径,骨料及界面过渡区影响劈裂扩展路径造成裂缝分叉出现,混凝土基体的渗透性对其抵抗水力劈裂不利并影响失效软化过程.