The application of dcs to control system for circulating fluidized bed boiler , including the drum water level control , steam temperature control , hearth negative pressure control , fuel control and circulating fluidized bed temperature is introduced 摘要介绍了集散控制系统在循环流化床锅炉控制系统中的具体应用，包括汽包水位控制、蒸汽温度控制、炉膛负压控制、燃料控制和炉床温度控制。
Because there are three inputs accede to adister of water lever control system of boiler , it is easy to bring error of water lever controlling . this iartice puts forward two methods to dispel error of water lever : ( 1 ) assistant signal self - disappear 由于锅炉水位控制系统的调节器输入端常加有三个输入量,极易引起水位控制偏差,本文提出了两种消除水位偏差的方法: ( 1 )辅助信号自消方法( 2 )辅助信号对消方法。
During unit startup and load is lower than 15 % , drum level is controlled by feedwater control valve , feedwater pump remains at minimum safety speed ; when load is between 15 % and 25 % , feedwater control valve is closing at fixed speed determined by function module , main motor - operated - valve is opened automatically , control mode of drum level is transferred to feedwater pump automatically and bumplessly ; when load is between 25 % and 50 % , control valve is closed fully , and main motor - operated - valve is open fully , drum level is controlled by one pump ; when load is more than 50 % , first pump is kept in operation , second pump is putting into operation automatically and 在机组启动、冲转及机组并网至15 %负荷阶段,给水泵维持在最低安全转速下运行,汽包水位由低负荷给水调节阀自动控制; 15 %至25 %负荷阶段,给水调节阀由函数模块按照一定的速率自动平滑关闭,主给水电动门自动打开,汽包水位控制方式自动无扰切换为给水泵自动控制;负荷在25 %至50 %阶段时,给水调节阀已完全关闭,主给水电动门已完全打开,水位控制已全由单台给水泵承担;负荷大于50 %后,在第一台给水泵运行的同时,第二台给水泵自动无扰投入。
The paper is committed to the research on the application of fault diagnosis and fault tolerant control in the modern power plant . the new schemes of fault diagnosis both for boiler water level control system and unit coordinated control system are presented ; moreover , based on the lqg strategy , a scheme of fault tolerant control for unit coordinated control system is also proposed 电厂热工控制系统的安全运行已经成为人们日益重视的课题，在这种背景下，本文致力于故障诊断与容错控制在电厂热工控制系统中的应用研究。主要内容是针对电厂锅炉汽包水位控制系统和电厂单元机组协调控制系统提出两种故障诊断的新方案；并且把lqg控制策略应用于单元机组协调控制系统，提出了协调控制系统的主动容错控制方案。
In this paper , we discuss many kinds methods of fec . we take a second - order water level control system as the controlled object to study the control structure based on internet , put forward a 3 - layer model , that is client / server / on - site model , and adopt vb + socket technology to realize multi - users communication 系统实现是以二阶水位控制系统为对象，研究了基于intemet的控制结构，提禅出了系统的三层模型，即客户/服务器/现场模块，采用vb + socket技术，面向多用户通信。
In this paper , we analyze the statistic characters of time - delay in detail , and put forward to adopt elman nn to forecast time - delay intelligently , design appropriate compensator based on adaptive smith forecast theory . the experiment results prove that this method can improve the forecast accuracy and system ' s dynamic performance . in the application of real time data transmission , forward error correction ( fec ) is a good method to resume the lost data 针对这个问题本文进行了详尽的统计特性分析，并且提出采用elman动态神经网络结构对网络时延进行智能预测，并根据自适应smith预估补偿控制原理设计合适的时延补偿器，并且应用于基于web的二阶水位控制系统中，实验结果证明了采用此方法可以提高预测精度，使时延补偿器适应时延变化的动态性更强，从而在保证系统稳定性的基础上，西安理工大学硕士学位论文提高系统的时延补偿精度。
On the base of studying in arithmetic of predictive control , different math models are used to approach the control system . general water level control , pid control and predictive control using in sewage pumping station are compared . by simulating the different models using in control system , the conclusion that the aim of saving power and preventing pollution in sewage pumping station can be achieved by using predictive control is got 在预测控制算法研究的基础上，分析了用不同的数学模型逼近污水泵站排放系统，比较了采用常规水位控制、 pid控制和预测控制对污水泵站排放系统的控制效果，在仿真结果对比的基础上，得到了采用预测控制可以更好的解决节能无污控制目标的结论。
2 . a scheme of instrument fault detection in boiler water level control system is presented based on the parity space method . the processes of the fault detection of instruments of steam flow , feed - water flow , and water level are introduced , the effectiveness of the fault detection scheme presented is shown by the simulation results （ 2 ）将一致空间算法（ willsky - chow方法）用在汽包水位三冲量控制系统中，提出了对于汽包水位控制系统的仪表故障进行快速准确检测的新方法，仿真结果表明该方法能够快速、准确实现故障的检测。
Based on the review of recent advances in surveying and controlling techniques of river models , described in this paper is a new controlling technique , which makes use of a two - way axial - flow pump and a immersion pump to control the up - boundary condition of discharge and the down - boundary condition of water level respectively , with the tidal model of the huangpu river estuary as an example 在对河工模型量测与控制技术进行回顾的基础上，以黄浦江河口潮汐河工物理模型为例，介绍了潮流河段上边界采用轴流泵进行双向流量控制、下边界采用潜水泵进行水位控制的新技术。
The problem of modeling and control is a attention focus of people . the boiler water lever is importance index of industry boiler safety and satabilization . it is importance meanimg to ensure water level in definite range for increasing quality of steam and reducing wastage of equipment and insuring safety of whole hert - power - net at present , the mostly method is adopt the routine pid control 锅炉的建模与控制问题一直是人们关注的焦点,而汽包水位是工业锅炉安全、稳定运行的重要指标,保证水位控制在给定范围内,对于提高蒸汽品质、减少设备损耗和运行损耗、确保整个网络安全运行具有重要意义。
