西门子SGT5-4000F型联合循环机组排气温度协调控制分析

以西门子SGT5-4000F型联合循环机组为例,就对机组启停及运行具有重要影响的排气温度控制进行了分析,说明了排气温度控制的作用、控制原理以及影响排气温度控制的各种因素,为相关的事件分析和优化工作提供了基础。     

燃气-蒸汽联合循环机组在热电联产中的应用

简要介绍了蒸汽轮机循环、燃气-蒸汽联合循环与燃气轮机循环的不同之处,并在此基础上,阐述了蒸汽轮机热电联产与联合循环热电联产的区别。介绍了燃气-蒸汽联合循环设备,阐述了燃气－蒸汽联合循环在热电联产中的应用和联合循环热电联产的优点,以期为今后燃气-蒸汽联合循环机组的有效应用提供一定的参考。     

一种提高燃气轮机联合循环效率方法的可行性分析

针对调峰性质的9E型燃气-蒸汽联合循环机组启停机频繁,可能在部分负荷状态下运行的特点,探讨当燃机处于部分负荷状态下长时间运行时,通过改变燃机IGV控制方式来提高排烟温度,进而提高联合循环机组的整体热效率的一种方法。本方法不同于IGV温控,而是通过修改常数CSKGVSSR来推迟IGV从最小全速角57°开启到84°角这一动作到来的时间,从而使燃机在部分负荷时,能够获得较高的排烟温度,便于余热锅炉快速地升温、升压,以提高联合循环机组的整体热效率。相比IGV温控,这种方法对燃机排烟温度的控制更加灵活、有效。     

GE燃机MARK Ⅵ控制系统与DCS通讯故障分析

以杭州半山天然气发电工程的9FA燃气-蒸汽单轴联合循环机组为例,概述了GE MARKⅥ燃气轮机控制系统和西屋OVATION DCS的网络构成,及二者实现以太网通讯的一般方法;针对国内外普遍存在的两系统间的通讯故障,结合实际,分析了通讯故障发生的诱因,并给出了现实可行的解决方案.     

燃气-蒸汽联合循环发电机组一次调频控制系统

电网供电频率是评价电能质量的重要指标,频率超限会严重影响发电、电网、用户的安全和经济效益.研究和完善入网燃气-蒸汽联合循环发电机组的一次调频系统,对于提高电网稳定性至关重要.该文介绍了燃气-蒸汽联合循环发电机组的特点,并以M701F4型“二拖一”燃气-蒸汽联合循环发电机组为例,介绍了该类型机组一次调频控制系统及控制方式,为同类型机组一次调频提供参考.     

中冷回热循环燃气轮机动态仿真研究

中冷回热循环燃气轮机是一个高度非线性的热动力系统,其动态性能由转子的转动惯性、容积的容积惯性和换热器的热惯性所决定。根据中冷回热循环燃气轮机的各部件特性,利用M atlab/S im link仿真平台,采用模块化建模法,对中冷回热循环燃气轮机进行动态仿真。通过实例,对中冷回热循环燃气轮机的动态性能进行分析,并与简单循环燃气轮机仿真结果进行比较。结果表明,换热器的时间常数较大,其热惯性对机组的动态性能影响较大,在仿真过程中不能忽略,且机组平衡时间与换热器时间常数有关,时间常数愈大,达到平衡所需时间愈长。     

可转接重载多路复用端子在济钢燃气-蒸汽联合循环发电多套机组重为备用中的应用

本文主要介绍可转接重载多路复用端子在济钢燃气-蒸汽联合循环发电多套机组互为备用改造项目中的优势对比、系统选型、硬件集成及软件改进等方面的情况,其使用灵活、安全可靠、节省投资的特点,给济钢联合循环发电不同机组的互备提供了良好的支持,效果十分明显。     

可转接重载多路复用端子在济钢燃气——蒸汽联合循环发电多套机组互为备用中的应用

本文主要介绍可转接重载多路复用端子在济钢燃气-蒸汽联合循环发电多套机组互为备用改造项目中的优势对比、系统选型、硬件集成及软件改进等方面的情况,其使用灵活、安全可靠、节省投资的特点,给济钢联合循环发电不同机组的互备提供了良好的支持,效果十分明显。     

基于模糊PID算法的空调机组温度控制

针对中央空调系统空调机组温度控制的非线性、滞后性及时变性等特点,设计了基于模糊PID算法的空调机组温度控制系统,实现了空调机组温度的实时在线控制.该系统选用MCGS组态软件实现系统运行状态的监控,使用西门子S7-1200 PLC进行现场设备控制.运行结果表明模糊PID控制器设计合理,有效改善了空调过程的调节品质,提高了空调机组的温度控制质量.     

浙江省联合循环机组热控系统故障分析及措施

结合收集整理近年来浙江省主要联合循环机组热控系统的故障处理情况,从系统软件硬件、信号测量、执行机构和现场设备维护等方面,分析了存在的故障隐患,提出改进的建议措施。供联合循环机组热控系统检修维护及新建机组设计参考。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.