钢丝帘布压延生产线控制系统

介绍钢丝帘布压延生产线控制系统,该系统由PLC、工控计算机和HIM（人机界面）通过工业以太网进行数据交换,同时配有ControlNet通讯模块和远程I／O、变频器及直流驱动器,完成压延生产线的操作、配方程序设定、运行状态监控和运行数据传输。主机部分由主机传动控制系统、整经辊液压控制系统、钢丝帘布厚度自动调整系统和辊简温度控制系统组成;辅机部分由大张力控制系统和卷取控制系统组成。     

基于SIMATIC ET200SP分布式I/O的辊压机控制系统的结构设计

通过研究辊压机集中式布置控制系统的结构和优缺点,设计并开发了一种基于SIMATIC ET200SP分布式I/O系统的辊压机控制系统。集中式布置辊压机控制系统可实现设备的统一调度、集中控制,但兼容性及扩展性较差,施工维护难,经济投入大;而基于SIMATIC ET200SP分布式I/O系统的辊压机控制系统具有高度灵活、可扩展、功能全面、可靠性及安全较高的优点,已成功应用于多个现场。某项目现场实际应用显示,分布式I/O辊压机控制系统安装周期较预期缩短了约60%,施工投入减少了约50%,线缆使用量减少了约80%,系统运行稳定,经济效益显著。     

炼油厂火炬程控柜I/O输出及通讯电缆事故分析与处理

炼化企业程控柜I/O输出及通讯电缆由于设计或安装中的细小差错会导致系统设备运行误动作,给整个装置的安全平稳运行带来隐患,本文以独山子大炼油火炬点火程控系统典型事故为例进行了分析,并对程控柜I/O输出及通讯电缆设计施工缺陷进行了整改。     

合成二仪表改造简介

合二仪表改造采用FOXBORO公司的I/A’S系统替换原来的可编程调节器和TDC-3000,增加I/O点,改进联锁和控制系统,并更换仪表线路和部分二次仪表。     

浅谈集散控制系统在太阳能超白光伏玻璃生产线上的应用

集散控制系统主要应用在太阳能超白先伏玻璃生产线上的热端。利用FOXBORO生产的最新一代I／A Series智能自动化系统实现对太阳能超白光伏玻璃生产线热端各项控制回路数据参数的设置和修改,从而达到生产线上生产工艺过程的变换。该系统自动化程度高,人机界面直观易懂、操作方便,并具有实时监控性,大大提高了生产效率。     

机动车尾气排放检测与维护（I/M）制度实施的问题与对策

机动车尾气排放是移动源污染的主要来源,严重影响城市空气质量和市民的身体健康。为打赢蓝天保卫战,严格执行机动车排放检测与维护（I/M）制度,强化机动车尾气排放检测,规范超标车辆闭环管理,是控制机动车污染物排放及改善城市环境质量的重要举措。基于此,本文主要探讨机动车排放检测的方法,并针对机动车排放检测与维护（I/M）制度存在的问题及改进对策进行探究,确保I/M制度顺利推进与实施。     

SIMATIC WINCC系统应用中的问题及处理

我厂2500t/d熟料生产线上的自动化控制系统采用的是基于西门子公司的SIMATIC Wincc5．0 DCS控制系统，于2003年11月投运。该DCS系统由一个工程师站ES，4个操作员站OS，4个过程控制站组成，如图1所示。4个过程站(ET200M现场I／O站)分别为原料磨 原料调配远程站、烧成窑尾站、烧成窑头站和煤磨站。     

基于PLC的自动加料机控制系统

阐述了基于PLC的自动加料机控制系统的构架,并分别介绍了自动加料机的工艺要求、PLC模块I/O端口的分配、程序结构、软件的选择和系统的功能及保护等.     

尿素成料包装自动设计

立足于用三菱PLC实现工业生产中尿素的装料、称重、包装的自动控制系统设计。通过对尿素成粒工艺过程的分析以及对称重、装料过程控制要求的确定,明确了控制系统整体的工作流程,并针对该控制系统进行了具体I/O口的分配以及程序框图编辑,保证了控制系统功能的完备以及系统的正常运行。     

化肥厂ESD系统的应用分析

叙述了ICS公司的ESD控制系统Regent+plus在日产1000短吨合成氨大化肥装置的应用实例,具体介绍了该系统的控制器组件、I/O组件、I/O电源组件,并对该系统的实际应用状况和效果进行了分析.     

Economical study of a small-scale direct contact humidification-dehumidification desalination plant

Economical study of humidification-dehumidification desalination (HDD) pilot plant was made in order to estimate the economic benefits of the process in comparison with a small-scale reverse osmosis (RO) system. The energy recovery of the unit was investigated to be 75%. Some theoretical modifications were made to the HDD system in order to reduce the energy costs of the unit. Exact and clear economic analysis results were obtained using COMFAR ΙΙΙ software including fixed investment costs, production costs, internal rate of return on investment, operating costs, energy costs and some other economical parameters. Based on the energy prices in Iran, the total fresh water production cost was calculated to be $ 6.4/m³ that was nearly the same as produced by an imported RO plant. Finally some points were recommended whether to choose HDD or RO plant in different cases and capacities.     

减少乙二醇装置循环气冷凝液系统聚合物生成

针对环氧乙烷/乙二醇装置循环气洗涤泵入口过滤器频繁堵塞的问题,分析了循环气冷凝液系统固体聚合物的生成机理,聚合物生成对装置生产造成的影响,以及可能减少聚合物生成的因素,并在操作优化上进行实践,操作优化后固体聚合物生成明显减少,对装置平稳生产带来了积极影响。     

太阳能光热-光电中空纤维真空膜蒸馏系统理论与实验研究

自主设计并搭建了太阳能光热-光电中空纤维膜蒸馏系统,太阳能光热采用面积1.82 m²真空管集热系统,光伏发电采用面积1.63 m²多晶硅电池板。实验方面,研究了不同工况下,热料液在不同流动方式时膜通量的差异;研究了在不同跟踪方式下太阳辐照度对系统性能的影响。结果表明：料液在管程流动的膜通量大于壳程的膜通量,且进口料液温度取50~70℃之间为宜;自动跟踪下膜组件入口温度比非跟踪高2~3℃,可以延长膜蒸馏系统运行时间1~2 h,且在相同的自然环境下,自动跟踪方式最大膜通量8.89 kg/(m²·h)远高于非跟踪方式时4.26 kg/(m²·h)。理论方面,分析了以水为工质的中空纤维膜蒸馏的传热和传质过程,建立了传热传质理论计算数学模型;分析了辐照强度、膜表面温差、膜丝内表面传热系数、传热与传质通量的定量关系,计算了膜面温度与理论膜通量,对比了实验值与理论值。系统运行稳定,能量综合利用效率高,性能可靠,为工程应用奠定了理论和实验基础。     

Gel permeation chromatography method for GPC system definition and performance evaluation

A practical method for the overall performance evaluation of a GPC system (columns) is described. System performance is defined as the ability of the system to give experimental M?_n and M?_w values (uncorrected for instrumental spreading and other distorting factors) which agree with the theoretical values, and it is expressed as the per cent deviation between the theoretical and experimental values. The method consists of running blends of monodispersed polystyrene standards of known compositions through the GPC system to be evaluated. From the resulting chromatograms, their M?_n and M?_w values are calculated (experimental). The theoretical M?_n and M?_w values of the same standards are also calculated from the formulas on the basis of their composition. By plotting the per cent difference of the experimental values from the theoretical values versus the theoretical values on a semilog scale, the overall performance of the GPC system under investigation is pictorially depicted. Results indicate that performance under experimental conditions can vary significantly from system to system. Results also indicate that performance of a system can be improved and optimized by proper column selection and system modifications.     

Numerical analysis of injection characteristics using biodiesel fuel

This paper deals with numerical analysis of injection process using biodiesel/mineral diesel fuel blends with the aim to search for the potentials to reduce engine harmful emissions. The considered fuels are neat biodiesel from rapeseed oil and its blends with mineral diesel D2. For the numerical analysis a one-dimensional mathematical model is employed. In order to model accurately the investigated fuels, the employed empirical expressions for their properties are determined by experiments. To verify the mathematical model and the empirical expressions, experiments and numerical simulation are run on a mechanical control diesel fuel injection M system at several operating regimes. Injection process at many different operating regimes and using several fuel blends are then investigated numerically. Attention is focused on the injection characteristics, especially on fuelling, fuelling at some stage of injection, mean injection rate, mean injection pressure, injection delay and injection timing, which influence the most important engine characteristics. The analysis of the obtained results reveals that, while keeping engine performance within acceptable limits, harmful emissions can be reduced by adjusting appropriately pump injection timing in dependence on the biodiesel content. This prediction is also confirmed experimentally.     

An application of queuing theory to the dynamics of anodic dissolution

Queuing theory is applied to oscillatory phenomena encountered during anodic dissolution, with numerical illustration provided by a laboratory-scale copper dissolution process. The theory interprets oscillation as a two-phase process, where the first phase consists of ion arrival to the electrode and subsequent steps to form a solid deposit on it, and the second phase consists of the deposition process itself followed by partial dissolution of the deposit. The two phases correspond to the process of client-arrival and client-servicing in queuing theory. In particular, the M/M/1, the G/M/1 and the M/M/k queuing models are quantitatively compared in terms of queuing time and certain other queuing characteristics.     

辊压机粉磨系统的调试与改进

长治钢铁集团瑞昌水泥有限公司采用了辊压机粉磨系统,在系统调试与生产中,针对由于原料及操作控制等原因引起的辊压机运行不稳,导致系统紊乱等问题,采取有效措施并严格控制原料质量,同时添加有助磨作用的混合材,迅速达到了辊压机系统的连续稳定运行,实现了水泥粉磨系统的高产高效。     

Texaco煤气化工艺技术经济指标的评价方法与评价系统设计

目前Texaco煤气化工艺的技术经济指标评价多采用手工作业方式，工作量大而且繁琐。针对这一现状，在分析Texaco煤气化工艺流程的基础上，运用物料衡算、热量衡算方法，获得了Texaco煤气化工艺的碳转化率、冷煤气效率、比煤耗、比氧耗等指标的计算方法。通过具体计算这些评价指标，即可定性、定量地评价整个工艺系统的运行状况。在此基础上，采用VB6．0、Access7．0等开发工具，开发了Texaco煤气化工艺技术经济指标评价系统。该系统支持多用户、多数据库、多报表、多权限，界面友好，操作简单，具有很好的应用前景。     

丙酮废液处理系统的设计

由于目前丙酮废液处理系统控制点分散、自动化程度低且采用间歇精馏工艺,从而导致生产效率低、丙酮提炼纯度差且故障率高,鉴于此,设计了基于PROFIBUS与MPI总线技术的分布式控制方案,采用连续精馏工艺、PID控制策略有效地克服了人工控制精度低、操作运行繁琐等缺点,并采用SIEMENS PLC与WANGO防爆I/O模块相结合的方式解决了系统的本质安全。现场调试结果表明,系统操作简便灵活,人机界面友好,性能稳定可靠。     

n（SiO2）／n（B2O3）比对无公害熔剂性能的影响

以碱一硼一硅系统为研究体系,探讨了n(SiO2)/n(B2O3)比对无公害熔剂光泽度、耐蚀性、膨胀系数等性能的影响规律。用高温显微镜、热膨胀仪、光泽度仪、显微硬度仪测试了不同硼硅比的无公害熔剂的主要性能,分析了其性能变化的原因。实验结果表明,n(SiO2)/n(B2O3)为1.6～2.0时,熔剂的各种性能与彩烤效果较好。