基于ADAM5510的燃煤注汽锅炉控制系统

为降低稠油热采燃料成本,利用ADAM5510构建了燃煤注汽锅炉控制系统.采用上、下位机分层结构,分别完成数据采集、实时控制和过程监控.针对燃煤注汽锅炉控制中的诸多不确定因素,对蒸汽压力、风煤随动控制环节进行了设计.在蒸汽干度控制策略实施过程中,提出了恒压力和恒流量两种控制策略,采用了工程实用的前馈-反馈控制复合控制技术,确保了蒸汽干度控制的精度和稳定性.     

超超临界机组分离器水位模糊控制仿真研究

超超临界机组汽水分离器在机组启动及高、低负荷下的运行状态不同,所起到的作用也不同;在汽水分离器湿态运行模式下,分离器内为汽水混合物,分离器起汽水分离作用,因此通过控制给水流量来控制分离器水位对机组的稳定运行起着重要作用;通过设计模糊控制器来实现汽水分离器的水位控制,并采用 MATLAB 仿真软件对控制系统进行仿真,得出相关参数和运行曲线;结果表明,采用模糊控制能够有效的避免或削弱PID控制中超调的现象,且具有较强的鲁棒性,有效地提高了控制品质。     

直流锅炉蒸汽发生器的模块化建模与仿真

为简便、全面地研究直流锅炉蒸汽发生器的动态特性,采用了模块化和移动边界法相结合的方法,建立了直流锅炉蒸汽发生器的数学模型.建模过程中,将蒸汽发生器划分为水冷壁、汽水分离器两大模块,其中水冷壁分为三段,采用非线性集总参数移动边界法建立三个独立模块;汽水分离器采用集总参数法建立干式运行模块.在仿真模型的基础上进行动态仿真试验,试验结果与实际系统的动态特性相符,不仅成功解决了大扰动全工况仿真问题,而且使得二次建模过程更为简便.该模型的建立,为直流锅炉系统工程分析和大规模火电厂仿真机的开发打下了良好的基础.     

一种注汽锅炉蒸汽干度控制方法

了实现注汽锅炉蒸汽干度的高质量控制,提出一种蒸汽干度控制方法．该方法采用基于T—S模糊模型的模糊预测控制获得主回路控制量,来自水流量的前馈控制量与主回路控制量相乘,形成蒸汽干度的前馈-反馈控制,以实现水火量的自动跟踪,同时在控制结构中引入非线性跟踪-微分器以增强系统的抗干扰能力．应用结果表明该方法具有良好的控制效果．     

注汽锅炉蒸汽干度的多变量预测控制

鉴于油田注汽锅炉出口蒸汽干度控制系统的当前状况,在分析蒸汽干度对象的特性及其影响因素的基础上,提出了注汽锅炉蒸汽干度的多变量预测控制系统(Multi-vari-able Predictive Control System)。该系统在蒸汽于度出现偏差时,通过燃料量和给水量的协调控制,快速消除蒸汽干度偏差,并且使给水量平稳地回复到给定值,维持锅炉的给定出力。仿真研究表明,该多变量预测控制系统具有良好的控制性能,并且算法简单、易于实现。     

注汽锅炉球形汽水分离器液位测量

阐述了高温、高压、压力变化范围宽的汽水分离器液位测量原理,实现了经补偿的汽水分离器液位测量,从而提高了分离器液位控制的准确性、稳定性和可靠性。     

稠油热采锅炉蒸汽干度时滞串级优化控制

开采稠油通常采用注热法,其中,以注蒸汽法应用最为广泛。为了实现注汽锅炉蒸汽干度的高质量控制,依据辩识的对象参数,采用单变量时滞ITAE优化控制的方法,进一步研究时滞串级系统设计的优化算法,使时滞难控度小于1.4的系统都有理想的控制性能和较好的鲁棒性。给出工业实例的数字仿真,相应地调试处理方法,能提高控制稳定性,适于在同类对象控制系统中推广。     

900MW超临界直流锅炉的数学模型与仿真研究

结合“上海外高桥电厂900MW锅炉机组”的具体特点,该文建立了一套整体式非线性固定边界的超临界直流锅炉蒸发器的仿真模型、炉膛的燃烧模型、启动分离器模型和过热蒸汽的仿真模型。分析了蒸发受热面传热系数的变化、燃烧器的结构对烟温的影响、炉膛辐射热量分配方案、以及分离器蒸汽干度、过热器蒸汽凝结的计算方法。通过实时仿真计算,以及对仿真模型的阶跃扰动测试,证实该模型的合理性,成功地解决了国内单机容量最大的火电机组900MW超临界直流锅炉的全工况实时仿真问题。     

节流法测量蒸汽干度浅析

1.概述利用节流法测量蒸汽干度,在热力学的教科书中早已有过介绍。一般所采用的方法是:蒸汽汽样经过节流孔膨胀至大气压,因为汽样的总热量比在大气压下饱和蒸汽总热量要大,从而使得汽样中的水汽化,经膨胀后的蒸汽进入过热区。因此,汽样的干饱和状态时的热量与测量热量之差是与蒸汽中的水分成比例的。根据绝热节流过程的焓相等,我们从焓-熵图中可查得,蒸汽压力为10kgf/cm~2时,蒸汽干度x>0.95,当蒸汽压力为5kgf/cm~2时,蒸汽干度x>0.97,对于实际蒸汽的干度,我们怎样去测量呢?     

旋风流渣式燃煤锅炉的微机监控系统

针对石油稠油热采的蒸汽发生器的蒸汽干度被控对象具有大延迟、严重非线性以及干扰因素多等特点,设计了微机监控系统.硬件采用模块化结构,组态灵活,可靠性高,操作方便.针对不同的工艺阶段和控制环节提出了相应的控制策略.应用结果表明,系统在多种工况下满足生产要求,具有推广价值.     

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.