水轮发电机定子铁损试验

定子铁损试验是检验发电机定子铁芯装配质量的重要方法,也是检验铁芯自身绝缘性能的重要工序。以江西柘林水电站5号机组为例介绍发电机定子铁损验的计算、实施及整理分析方法。     

Optimal blank design based on finite element method for blades of large Francis turbines

Metal pressing process that is widely used in industries has advantages over casting process for producing large Francis turbine blades from thick plates. Prior to the pressing process, blank design is firstly performed to determine flat blanks. The traditional trial and error approach is not applicable to blade design for Francis turbines that are not standard due to hydraulic characteristics of power plant sites. The rapid development of computing technology makes it possible to obtain optimal flat blanks by numerical modelling and simulation. In this paper, inverse finite element approach is investigated for blank design and an elasto-plastic model has been built using the well-known commercial software ANSYS. Numerical simulations for blade unfolding models with thick shell elements, solid elements and shell elements have given results with negligible differences. Unfolding tests with simple geometries have been carried out and the numerical results agree well with the analytical solutions. A large and thick shape of a Francis turbine blade for a hydropower plant has been successfully unfolded by inverse FE model. Sensibility analysis shows that the middle surface of the flat blank is independent of blade thickness. For ensuring the machining of the blade after the pressing process, a new contour is obtained by extending the boundary of the flat blank provided by the numerical model. This research may provide a useful tool for optimal blank design of Francis turbine blades.     

PLC控制系统在CCPP中的应用

本文主要介绍了重钢集团股份有限公司的CCPP（燃气-蒸汽联合循环发电机组）特点和PLC控制系统在这个项目中应用。PLC控制系统完成了CCPP工程中的燃气轮机、煤压机、余热锅炉、汽轮机等主体系统的主要功能和控制逻辑,在整个项目中起到了举足轻重的作用。     

基于VB的风力机叶片外形优化设计

为了实现风力发电机风轮叶片外形的优化设计,以风场风速分布为基础提出了综合优化目标;以片条理论为基础提出了以展弦比为关键参数的修形约束条件的气动优化目标,建立了叶片外形优化设计的数学模型。采用枚举法和循环结构,选用Access数据库,应用Visual Basic编制程序实现叶片外形的优化设计。针对内蒙古某地区设计了1.5MW风力机叶片,与国外同功率某通用叶片进行了对比分析。结果表明,两种叶片外形基本吻合,而且文中设计的叶片在性能上有明显优势,同时也验证了文中提出数学模型的可靠性和程序的实用性。     

Turbine框架在Web开发中的应用研究

从MVC设计模式视角,分析了Turbine框架的Torque、Velocity和Turbine等主要组成部分及其工作原理,并结合一个制造业库存管理系统开发应用实例,提出了一种应用基于MVC设计模式的Turbine框架开发Web应用系统的设计方法。     

飞机主系统液压泵转速测试仪的设计与仿真

为给主系统液压泵转速装置的定检提供参考,设计了主系统液压泵转速测试仪。硬件设计包括单片机和液晶显示器四个模块;软件设计包括定时器T0的中断服务、计数器T1的脉冲计数和液晶的驱动三个模块。基于Proteus平台并利用模拟的霍尔脉冲信号对设计进行了仿真,结果表明,测试仪的软硬件设计正确。     

模糊自整定PID的船舶蒸汽动力负荷控制

船舶蒸汽动力装置自动控制的首要任务是机组的负荷控制。传统的PID控制算法由于具有结构简单、易于实现、可消除静差等优点得到了广泛的应用,但它受控制对象的影响较大,只有在各参数整定良好的前提下才能得到满意的控制效果。根据上述情况,结合船舶蒸汽动力单元工况变化频繁的特点,提出一种基于输出响应的自适应PID算法,以提高控制系统适应负荷变化的能力。方法在保留传统定值PID控制算法优点的同时,引入模糊控制在线整定PID控制参数,改善了机组的负荷控制特性,具有一定的工程应用价值.     

超临界直流炉蒸汽发生器的建模与仿真分析

研究以某600MW机组超临界直流炉的蒸汽发生器为对象,从过程基本方程出发,建立单相及两相受热管动态特性的动力学方程.采用随体导数法建立了关于在亚临界及超临界工况的非线件分布参数动态数学模型.针对蒸汽发生器在两种典型工况下的动态特性进行了仿真研究,所得结果,对进一步研究超临界直流锅炉的安全运行中全工况动态仿真提供有意义的设计参考.     

含泥砂河流水轮机增容改造的探讨─刘家峡2~＃水轮机增容改造

本文简要叙述了刘家峡电厂水轮机增容改造中的水力研究、结构设计、中间试验、材料选择以及制造工艺等方面内容,并探讨了减轻泥砂磨蚀的措施。该水轮机的增容改造经验对含泥砂河流水轮机的设计与改造是有益的。     

Characterization of laser hardened steels by laser induced ultrasonic surface waves

Ultrasonic surface waves are suitable for the characterization of surface hardened materials. This is shown on laser hardened turbine blades. The martensitic microstructure within the surface layer of surface hardened steels has a lower surface wave propagation velocity than the annealed or normalized substrate material. Because the propagation velocity depends on the ratio of layer thickness to wavelengthd/, its measurement allows the determination of the hardening depth. If the surface wave frequency is high enough, the surface wave propagates mainly within the hardened layer. A correlation of the surface wave velocity to the surface hardness has been found. Because the variation of the surface velocity in hardened steels is small, a high measurement accuracy is necessary to obtain the interesting hardening parameters with sufficient certainty. Therefore, a measuring arrangement has been developed where laser pulses, guided by optical fibers to the surface hardened structure, generate simultaneously surface wave pulses at two different positions. The two ultrasonic pulses are received by a piezoelectric transducer. The surface wave velocity is obtained from the time delay between these pulses which is determined by the cross-correlation method. To evaluate simultaneously surface waves with different penetration depths from the same signal acquisition, digital filtering has been used in connection with the cross-correlation.