丁二烯装置仪表控制优化分析

丁二烯装置DCS控制系统采用横河CS3000操作系统,随着运行时间延长,部分控制回路的控制方式存在不适合系统平稳运行的问题,部分控制回路有进一步优化的空间,通过修改控制方式,优化PID参数,促进了装置平稳运行,满足了装置平稳率及自控率控制要求,为装置长周期运行打下良好的基础。     

DCS控制功能块在连续重整装置中的应用

介绍了CS3000 DCS在某连续重整装置中的应用,重点给出该装置中几个复杂控制回路的实现和组态。     

用VB编写麻花辫切换程序

我厂气化装置中FIC1305控制回路中有三个控制回路,分别来自三套气化炉的洗涤塔液位控制回路,同时控制其出口流量的三个调节阀,三个管道由一条管道进入闪蒸罐.但三个调节阀可以相互切换控制,既三个管道的水可以走不同的调节阀,实现此切换用TPS系统组态很难实现阀与阀之间的切换,但用TPS提供的脚本语言VB则可以方便实现.     

汽油加氢脱硫装置DCS中两个复杂控制回路的实现

介绍某225万t／a催化汽油加氢脱硫装置,采用HONEYWELL Experion PKS系统,实现轻汽油抽出和选择性加氢反应器入口温度两个复杂控制回路的非常规控制模块的实现方案。     

分程控制方案在天津乙烯装置上的应用及组态

在乙烯生产中,分程控制(调节)是经常采用的控制方案之一。天津14万t/a乙烯装置使用日本山武霍尼维尔生产的TDC-3000/APM控制系统,共有控制回路423个;其中分程控制回路22个,占5.2％。采用分程控制方案的目的包含两方面内容:一是从改善调节系统的品质角度出发,用分程控制     

自控应用软件通过技术鉴定

大庆化肥厂同时引进的两套PROVOX集散系统(DCS)分别用于合成氨和尿素两套生产装置。尿素装置引进的荷兰斯太来卡拜公司的多变量先进控制(MUVAC),它包括氨碳比、合成塔液面控制等25个复杂控制回路和25个单回路控制及215个监视点,全部引     

TPS系统在国产化聚酯装置的应用

介绍了采用国产化技术装备的聚酯装置工艺流程。阐述了TPS系统的基本结构、该系统硬件配置、冗余技术的应用。重点介绍几个典型复杂控制回路的组态方案。该系统已投入运行，稳定可靠，对同类装置有一定的借鉴意义。     

原油管道工程高压电机二次控制设计探讨

根据工程设计实例,分别对原油管道工程设计中高压电机采用不同起动方式的二次控制回路进行阐述,结合站控自动化系统,并针对生产实际操作需要,对电机二次控制回路设计进行分析总结,探讨高压电机二次控制优化设计方案。     

基于PLC的燃煤锅炉脱硝控制系统

聚酯生产装置共有5台58 600MJ的燃煤锅炉,为了使锅炉烟气中的NOx达标排放,在烟气排放前增加了脱硝装置,脱硝工艺采用选择性非催化还原法,以S7-300 PLC作为其控制核心,采用WinCC设计操作站的监控和数据采集系统,重点给出了模拟量的输入与转换、PID控制回路和氨水流量累积过程的组态和程序代码。     

MACS-K系统在化工区污水处理装置的应用

介绍了某石化公司化工区污水处理装置DCS(集散控制系统)采用MACS-K系统升级改造情况。在升级改造过程中主要完成三项重点工作:一是在装置连续生产的状态下,实施系统机柜安装及仪表回路迁移;二是编写了复杂机泵控制逻辑的程序;三是电气与仪表信号对接。升级改造后,MACS-K系统已在污水处理装置稳定运行3年多,未对周边生态环境造成不良影响。MACS-K系统不仅提高了装置日常生产的稳定性和可靠性,也为将来实施工艺流程优化的扩容工作奠定了基础。     

DCS在膜法除硫酸根工艺中的应用

介绍了膜法除盐水中硫酸根的工艺及其自动控制系统的主要控制回路和软硬件组成。     

熔纺氨纶交联剂控制系统的改进

用双泵代替单泵来控制交联剂的添加。交联剂经一级泵,采用压力闭环控制系统,产生较高的稳定的压力,再经二级泵,采用速度开环控制,达到准确的流量,解决了单泵系统难以同时控制2个被控量的难题,满足了熔纺氨纶工艺的要求。     

Multi-agent reinforcement learning for process control: Exploring the intersection between fields of reinforcement learning,control theory,and game theory

The application of reinforcement learning (RL) in process control has garnered increasing research attention. However, much of the current literature is focused on training and deploying a single RL agent. The application of multi-agent reinforcement learning (MARL) has not been fully explored in process control. This work aims to: (i) develop a unique RL agent configuration that is suitable in a MARL control system for multiloop control, (ii) demonstrate the efficacy of MARL systems in controlling multiloop process that even exhibit strong interactions, and (iii) conduct a comparative study of the performance of MARL systems trained with different game-theoretic strategies. First, we propose a design of an RL agent configuration that combines the functionalities of a feedback controller and a decoupler in a control loop. Thereafter, we deploy two such agents to form a MARL system that learns how to control a two-input, two-output system that exhibits strong interactions. After training, the MARL system shows effective control performance on the process. With further simulations, we examine how the MARL control system performs with increasing levels of process interaction and when trained with reward function configurations based on different game-theoretic strategies (i.e., pure cooperation and mixed strategies). The results show that the performance of the MARL system is weakly dependent on the reward function configuration for systems with weak to moderate loop interactions. The MARL system with mixed strategies appears to perform marginally better than MARL under pure cooperation in systems with very strong loop interactions.     

基于相角裕度优化的PID参数整定方法研究

针对复杂工业过程的大滞后、参数不确定等特性,提出一种新的鲁棒PID控制器参数整定方法.该方法通过使系统开环传递函数的相角裕度最大化,来求取各个PID参数.由于该方法的稳定裕量是通过取明确依赖于频率的模型来获得,从而避免了陷入保守性.仿真结果表明,使用本文提出的控制器整定方法,在命令输入发生阶跃变化时,控制系统都有很好的动态响应,同时在系统参数发生变化或存在未建模动态时,也能保证系统的稳定鲁棒性.     

DISTRIBUTED DATA COMMUNICATION NETWORKS FOR REAL-TIME PROCESS CONTROL

The paper deals with the performance analysis of network access protocols for distributed data communication and control systems (DDCCS) in chemical and processing plants. The selection of an appropriate data highway protocol is an important step in the DDCCS network design for large-scale processes because the real-time feedback control loops are subject to time-varying delays resulting from data latencies and possible mis-synchronism between system components.

SAE token ring, SAE linear token bus, and MIL-STD-1553B protocols have been analyzed in view of the DDCCS network design requirements. The results of closed loop control system simulations are presented to demonstrate how data latency generated by the network access protocols could degrade the dynamic performance of the controlled process.     

基于虚拟仪器技术的煤气发生炉气化层温度控制系统设计

基于LabVIEW的虚拟仪器温度测控系统是针对煤气发生炉工艺流程运行特点的要求而设计的,通过在线气化层温度测量,实时检测造气炉温度状态和变化趋势,实现对工艺参数的动态调整和闭环控制。介绍该测控系统的设计方案、软件设计和系统实现。     

化工过程多回路PID控制系统模式切换参数自整定

化工过程一般为多变量系统,但其主要控制方案为分散多回路PID常规控制。由于多变量系统内部存在不同程度的耦合作用,各控制回路之间存在相互影响,当其他回路进行手动/自动模式切换时,本回路等效被控对象将会发生突变,导致本回路的原有控制参数不能适应等效被控对象的变化,造成控制性能下降,甚至闭环系统不稳定。为避免这种情况的发生,从整个系统的角度研究控制回路模式切换时的稳定性,采用多变量频域Nyquist阵列设计法。基于对角优势下正Nyquist稳定性判据,从Gershgorin圆边界点的角度定量分析各个控制回路在模式切换前后的稳定性变化程度,从而确定各回路控制器增益的调整方向及程度,实现各回路的控制器参数在控制回路模式切换瞬间的自动整定,尽可能抵消控制回路模式切换对整个系统的扰动,保证整个系统的闭环稳定性。以Shell公司重油分馏塔的多回路PID控制系统为例,将3个PID控制回路依次投用时,根据Gershgorin圆边界点进行控制参数的自整定,闭环系统仍能保持一定的控制性能,否则闭环系统将不稳定。     

三水箱综合实验仿真平台的设计与应用

基于力控组态软件、Excel实时数据库和Matlab语言构建了一个三水箱系统的液位综合实验仿真平台.在综合实验仿真平台中,利用Matlab/Simulink完成三水箱开环系统的建模与仿真过程,选取Excel作为Matlab和力控组态软件通讯之间的动态数据库,利用DDE协议实现了数据传输等功能.最后利用力控组态软件实现三水箱系统的闭环控制、实时监控与报警等功能.     

聚丙烯装置复杂控制及顺序控制

结合聚丙烯工艺过程的特点，对装置中的复杂控制回路及顺序控制进行分析。介绍了工艺流程、软件编制和使用情况。     

Advanced process control for injection molding

This paper deals with the application of advanced control strategies to an injection molding process. Of particular interest is the control of one variable during the cooling phase of the molding process. Due to the cyclic dynamic nature of injection molding, the controlled variable must be regulated over a short cycle; the full process is completed within 10 seconds. Therefore, a key control objective is rapid setpoint regulation. A closed-loop strategy has been implemented for the regulation of pressure within the mold during the cooling cycle. First order plus dead time models of the process have been identified from plant step responses. The performance of several control algorithms for this process are compared in simulation studies. These algorithms have given comparable regulatory and servo responses. Finally, the effectiveness of the closed loop controi system has been demonstrated experimentally using the PI algorithm. Simulated and experimental results are in excellent agreement.