共查询到20条相似文献,搜索用时 109 毫秒
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介绍了某水厂加氯工艺的特点,并且对整个水处理加氯过程进行了分析,在工艺控制的基础上设定了控制策略,并且完成了加氯自动控制系统.由于水厂加氯非线性、不确定性强、大延时性等特点决定了现代水厂加氯系统无法取得精确的数学模型的特点,因此采用一般传统的控制方式来进行控制是不太现实的,最终提出了采用模糊控制先进控制算法进行控制策略. 相似文献
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以水厂后加氯自动控制系统为例 ,介绍了由PLC、流量计和余氯检测仪等构成的串级和比值系统的控制原理及系统运行步骤 ,表明了系统具有良好的控制品质 相似文献
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以水厂后加氯自动控制系统为例,介绍了由PLC、流量计和余氯检测仪等构成的串级和比值系统的控制原理及系统运行步骤,表明了系统具有良好的控制品质。 相似文献
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加氯环节是自来水生产过程中最为关键的一环。加氯系统的目标是使出厂水的余氯含量在某个范围内。针对加氯系统的大时滞,大惯性的特点,提出了自适应、比例投加与串联控制相结合的复杂控制系统。利用组态软件技术和PLC,在工程实际应用中对南京某自来水厂实现了加氯自动化控制,并取得了良好的运行效果。 相似文献
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中小型水厂计算机监控系统的设计与实现 总被引:1,自引:0,他引:1
针对当前中小型水厂监控系统的现状和存在的问题,从中小型水厂计算机监控系统的实际控制要求出发,对整个监控系统的网络结构和系统软件进行了构建.在系统设计过程中,采用了软件群层次化核心技术对系统进行优化.应用实践表明,该系统较好地满足了中小型水厂各种监控的需求,使水厂的高可靠性、可扩展、可维护性等各项指标都得到了提高,进一步提高了水厂的经济效益. 相似文献
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本文介绍了广州西洲水厂的自动化系统。简介了该水厂基于罗克韦尔自动化(AB)软硬件产品的集散式控制系统的组成及网络结构。详细描述了药物投加系统的工艺过程、控制机理和效果;滤池反冲洗和泵站控制的原理等。 相似文献
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Casper Schousboe Andreasen 《Structural and Multidisciplinary Optimization》2017,55(4):1301-1309
This paper presents a methodology for optimizing inertia driven dosing units, sometimes referred to as eductors, for use in small scale flow applications. The unit is assumed to operate at low to moderate Reynolds numbers and under steady state conditions. By applying topology optimization to the Brinkman penalized Navier-Stokes equation the design of the dosing units can be optimized with respect to dosing capability without initial design assumptions. The influence of flow resistance and speed is investigated to assess design performance under varying operating conditions. 相似文献
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The design, fabrication, and performance of a micro liquid dosing system are described. The system consists of a lead zirconate
titanate tube acting as a liquid level sensor with frequency output, a silicon micromachined piezoelectrically driven valve,
and an electronic control unit. For the valve a low leakage rate, i.e. an on-off ratio of the liquid flow of about 600 was
achieved. At a typical input pressure of 20 kPa a liquid flow of up to 500 μl/min could be controlled. 相似文献
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详细介绍了一种基于PLC的混凝剂投加控制系统的原理、控制策略、硬件构成和软件设计。该控制系统以透光率脉动检测值作为控制因子,采用双PID控制器的串级控制方式实现了混凝剂最佳投加量的控制,并引入流量比例前馈控制,保证了系统出水浊度的稳定。 相似文献
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This paper presents a temperature model of an industrial, semi-batch, emulsion-polymerisation reactor, which together with the already designed chemical reactions model is able to predict the temperature in the reactor as a result of varying operating conditions. The model was derived from the energy balance equations and validated on real-plant data. The model was used to analyse the influence of reactants dosing during the batch on the reactor temperature. The analysis shows that during the batch dosing of the two reactants, initiator and monomer, needs to be mutually balanced and adjusted to the current process situation, otherwise, the temperature in the reactor may become oscillatory and unstable towards the end of the batch because of the limited heat removal capacity of the condenser. To keep the reactor temperature in a narrow region also the control strategy was proposed that adjusts the monomer flow and initiator addition, using reactor temperature as a controlled variable. Simulation results show that the proposed reactants dosing control significantly reduces the variations in the reactor temperature and at the same time results in more uniform final batch results. 相似文献
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以自来水厂混凝投药大时滞过程为研究对象,在迭代反馈整定(IFT)方法的基础上,结合Smith预估控制结构,提出了一种混凝投药过程数据驱动直接控制算法.着重针对过程大时滞的特点,在性能指标中加入了预估误差惩罚因子.提出了一种新的步长设置方法,使得步长的下降速率可调.设计了3个闭环实验来求取性能指标梯度向量的无偏估计,完全... 相似文献
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L A Lenert J Lurie L B Sheiner R Coleman H Klostermann T F Blaschke 《Computers and biomedical research》1992,25(1):29-42
In this paper, we describe our design for advanced drug dosing programs that "reason" using a combination of Bayesian pharmacokinetic modeling and symbolic modeling of patient status and drug response. Our design is similar to the design of the Digitalis Therapy Advisor program, but extends this previous work by incorporating a Bayesian pharmacokinetic model, performing a "meta-level" analysis of drug concentrations to identify sampling errors and changes in pharmacokinetics, and including the results of this analysis in reasoning for dosing and therapeutic monitoring recommendations. The design has been implemented in a program for aminoglycoside antibiotics called Aminoglycoside Therapy Manager. The program is user-friendly and runs on low-cost general-purpose hardware. The initial validation study showed that the program was as accurate in predicting future drug concentrations as an expert using commercial Bayesian forecasting software and that its dosing recommendations were similar to those of an expert. 相似文献
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列车显示器语音测试时,调试员需要通过耳朵判断语音的质量,而调试员对语音的判断会受环境噪声、显示器装配等因素影响,造成了出厂的列车显示器语音质量存在不一致性的现象.对此,文章提出一种语音自动检测方法,其利用麦克风采集列车显示器发出的声音,采用感知语音质量评价(PESQ)算法对列车显示器发出的语音进行自动检测和评价.仿真结... 相似文献
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As feedback from Three Mile Island No. 2, a large amount of human–machine interface (HMI) design has been proposed to support
operators during accidents by presenting information on plant status, some of which is implemented in commercial nuclear power
plants (NPPs). However, it has not yet been discussed what role HMI should play under conditions where operators must take
action as instructed under emergency operating procedure. Regarding this principal issue, an HMI design is proposed together
with specific screen images. The advantage of this design is based on the involvement of an ex-operator in NPP in this paper.
The participation of users in the design of HMI has been rare. Accordingly the proposed HMI is comprehensive for average operators
and is expected to be acceptable for future implementation in commercial NPPs. The effectiveness of the proposed HMI has been
examined in a small experiment. 相似文献
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A pocket computer program has been designed to assist clinicians in the appropriate administration of most drugs exhibiting single compartment first-order elimination and either zero-order (intravenous infusions) or first-order (intramuscular and oral) absorption. The program utilizes well-established pharmacokinetic parameters to calculate an optimal drug dose and dosing interval based upon a patient's demographic characteristics and the drug half-life, volume of distribution, and absorption rate constant or infusion time. It also allows the user to estimate peak and trough drug serum concentrations. When measured serum concentrations are available during steady state, it is possible to determine individual patient drug half-life and volume of distribution for more accurate adjustments in dose and/or dosing interval. Usage of this program should enable clinicians to better select effective but safe drug dosing regimens based on individual patient needs and characteristics. 相似文献