石油化工行业DCS控制系统信号干扰原因及对策

DCS系统是一种分散式控制系统,或者集散式控制系统,是当前比较先进的控制系统技术。在化工生产中应用DCS控制系统,可以全面监督管理各个生产环节。而近年来随着计算机技术的发展,化工生产也在向着智能化和高效化方向发展,因此DCS控制系统也应更加安全、可靠、灵活、便捷,在化工生产中发挥更大的作用。而由于实际化工生产环境比较复杂,因此会干扰DCS控制系统信号,影响化工生产。本文主要分析内容就是石油化工行业DCS控制系统信号干扰原因及对策,要从化工行业各样DCS控制系统实际应用出发,探究相关干扰因素,采取合理措施,减少干扰的不利影响。     

过程自动化控制在化工企业中的运用

本文简要阐述了化工生产中过程自动化控制的概述,重点列举了过程自动化控制在化工企业中的具体运用,探讨了自动化控制系统在化工生产中的发展趋势。     

化工生产中DCS控制系统的应用

基于DCS控制系统的功能与结构及其特性,介绍了DCS系统在化工生产控制中的应用。针对工艺特点和控制要求,阐述了DCS控制方案的实施过程。运行结果表明,该系统具有良好的稳定性和实时性,对化工生产发展发挥了很大作用。     

PLC在华泰化工稀硝酸机组控制系统上的应用

针对硝酸机组的工艺特点及其技术要求，基于PLC可编程控制器技术，实现了化工机组生产过程监控的自动化撞制系统。讨论了由现场级、PLC控制级和HM1监控级3层结构组成的自动化控制系统的结构、功能和控制方法。用防喘振控制模式、启停车控制逻辑模式及PlD回路控制实现了机组控制的目标。所完成的控制系统成功地应用于安徽化工10^5t稀硝酸机组控制系统，实现了机组运行过程的实时监控、防喘振控制和启停车联锁逻辑等功能，取得了明显的成效。     

炼化装置控制系统接线实际应用规则分析

在炼油化工生产装置控制系统中,自动化应用程度比较高,控制系统应用的主要任务就是保证炼油化工装置生产的平稳和运行安全。本文介绍了炼油化工装置控制系统现场接线的规则及注意事项,以提高炼油化工装置控制系统的平稳运行率。     

间歇生产过程中的批量投料控制器

】介绍一种适合化工、轻工等间歇生产过程中液体批量投料的定量控制系统的构成和工作原理，详述了控制仪表的接口电路     

基于FF的现场总线控制系统在60万吨甲醇中的应用

中海石油建滔化工有限公司60万t／a甲醇项目采用YOKOGAWA现场总线控制系统（FCS），该系统具有控制分散化、诊断智能化以及性能稳定等优点，适应了化工生产过程中的高温、高压、控制精度高的要求，对甲醇的安全稳定生产和系统的优化控制提供了强有力的保证。     

清漆生产过程集散控制系统

面向清漆生产过程,考虑化工过程对系统安全性的需求,设计了一套冗余操作站、冗余网络和冗余CPU,具有极高性价比的集散控制系统。其中,控制站完成清漆生产过程的现场数据采集及控制信号输出;操作站实现操作人员对生产过程的实时监视和控制。     

ITCC系统在乙烯装置中的应用

在化工生产中,压缩机组作为大型化工转动设备,其应用相当常见。乙烯装置中的大型压缩机组有三套,即裂解气压缩机组、乙烯压缩机组和丙烯压缩机组。除压缩机自身性能影响着装置整体安全性和可靠性外,控制系统性能影响也比较大,因此,在乙烯装置中,压缩机组的控制应用非常重要。要提高机组性能,保障生产装置运行良好,需要选择合适的压缩机控制系统。ITCC压缩机控制系统可以在较大规模工程中应用来控制压缩机组,其可靠性高、功能性强,实际应用有效保障了生产进行。本文主要分析了ITCC系统在乙烯装置中的应用,以及其用户程序的改进等。     

化工自控系统维护管理综述

随着4C(Computer、Control、Communication、CRT)技术的发展,控制系统在化工生产过程中得到了广泛应用,而控制系统的可靠性和可用性是生产企业关心的重点。本文阐述了化工自动控制系统的资料管理、日常维护保养、检修及备件管理的方法和重要性,说明控制系统的维护和管理是生产装置安、稳、长、满、优运行的保障。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.