仪表联锁一体化控制单元(ITCC)在压缩机防喘振控制上的应用

介绍了基于PLC的压缩机一体化控制系统,PLC和现场总线系统(DCS)、安全仪表系统(SIS)、马达一体化控制系统(MCC)等信号之间的相互关系。主要论述了压缩机的防喘振控制理论,防喘振控制器的功能及防喘振控制在赛科乙烯装置裂解气压缩机的应用。     

离心式压缩机防喘振系统设计

介绍离心式压缩机的喘振机理、防喘振安全操作线及防喘振控制方案,并给出推荐方案。对离心式压缩机防喘振控制回路控制器的设置及仪表要求、压缩机出口管线布置设计等关键问题进行了分析。     

空气压缩机新型防喘振控制系统原理及应用

详细介绍防喘振控制系统的组成及防喘振控制算法,并以该控制算法精确建立了压缩机通用防喘振性能图.防喘振控制器根据压缩机通用防喘振性能图上喘振控制线进行PI控制,并通过快开控制线阶跃输出,安全状态控制加以配合,共同完成压缩机的防喘振控制.     

ITCC在压缩机防喘振上的应用

本文介绍TRICON控制系统在合成氨装置压缩机控制中的应用,论述了压缩机的防喘振控制理论,详细介绍了防喘振控制器的功能及防喘振控制程序以及在线维护喘振仪表的注意事项。     

浅谈离心式压缩机综合控制系统

就离心式压缩机综合控制系统的构成和所实现的功能作了简要的介绍,介绍了包括防喘振控制策略的构成以及在防喘振过程中各自所起的作用,实现压缩机性能控制的基本原理和改变压缩机工况点位置的几种基本方法。探讨了性能控制和防喘振控制之间的耦合关系,详细分析解耦条件以及采用解耦控制算法前后压缩机在性能上获得的改善。     

利用动态分程调节实现离心压缩机组的解耦控制

在分析离心压缩机组性能控制和防喘振控制的基础上,阐述离心压缩机组的性能控制系统与防喘振控制系统之间的耦合关系,并详细说明利用动态分程调节系统实现离心压缩机组解耦控制的原理和动作过程。     

ARGG装置用压缩机防喘振控制措施研究

压缩机是ARGG装置中重要的气体输送设备,压缩机喘振具有较大的危害性。本文分析了压缩机发生喘振的原因和容易诱发喘振的因素,介绍了压缩机特性曲线,探讨了喘振的防控措施,指出固定极限流量法应用范围较窄,目前可变极限流量控制器是主要的控制方法,要根据实际运行工况对其防喘振控制曲线进行修正,并按相应的策略做好压缩机操作和维护,以确保压缩机处于最佳工作状态。     

DR22控制器在压缩机防喘振控制系统中的应用

本文主要介绍苯菲尔蒸汽压缩机防喘振控制系统及其算法，以及利用西门子公司生产的ＤＲ２２控制器开发的一套防喘振控制程序。     

DR22控制器在压缩机防喘振控制系统中的应用

本文主要介绍苯菲尔蒸汽压缩机防喘振控制系统及其算法，以及利用西门子公司生产的ＤＲ２２控制器开发的一套防喘振控制程序。     

离心式压缩机防喘振控制及故障诊断系统研究与应用

针对离心压缩机喘振问题,基于PLC和CCC(S3++)防喘振控制器平台,通过喘振曲线计算以及PLC与CCC防喘振控制器的协调控制,实现了压缩机防喘振控制.另外,还针对常见的压缩机轴承故障,开发了神经网络智能故障诊断系统(上位机采用iFIX与MATLAB平台),有效地判断轴承故障原因.     

Fuzzy control of ethanol concentration for emulsan production in a fed-batch cultivation ofAcinetobacter Calcoaceticus RAG-1

A fuzzy control system was organized and applied to the control of ethanol concentration in a fed-batch cultivation process for emulsan production byAcinetobacter calcoaceticus RAG-1. The membership functions and fuzzy rules were determined by sets of data and experiences obtained from the preliminary culture experiments. The input variables, error (the difference between the set point value and the process variable) and the change of the error, were fuzzified by using the membership functions and the output variable, change of the ethanol feed rate, was inferred based on the membership functions and the given fuzzy rules. To obtain the numerical value for the output variable, the center-of-gravity method was used in the defuzzification procedure. The results showed that the ethanol concentration was well regulated around optimal level and the emulsan yield was increased compared with that of the cultivation controlled by the conventional feedback control loop.     

基于模糊逻辑的微乳液搅拌釜温度串级PID控制

为了提高某精细化工厂微乳液搅拌釜温度在不同工况下的控制精度,克服反应过程的非线性特性,满足多种产品的不同需求,开发一种基于模糊逻辑的串级PID控制器。该方法在原有典型PID串级控制器上增加了一个模糊调节器,根据釜温与设定值差、夹套温度与釜温差,及专家经验调节主回路PID参数。试验结果验证了该方法是有效的,能够提高系统控制精度。     

Modeling of a paper-making wastewater treatment process using a fuzzy neural network

An intelligent system that includes a predictive model and a control was developed to predict and control the performance of a wastewater treatment plant. The predictive model was based on fuzzy C-means clustering, fuzzy inference and neural networks. Fuzzy C-means clustering was used to identify model’s architecture, extract and optimize fuzzy rule. When predicting, MAPE was 4.7582% and R was 0.8535. The simulative results indicate that the learning ability and generalization of the model was good, and it can achieve a good predication of effluent COD. The control model was based on a fuzzy neural network model, taking into account the difference between the predicted value of COD and the setpoint. When simulating, R was 0.9164, MAPE was 5.273%, and RMSE was 0.0808, which showed that the FNN control model can effectively change the additive dosages. The control of a paper-making wastewater treatment process in the laboratory using the developed predictive control model and MCGS (monitor and control generated system) software shows the dosage was computed accurately to make the effluent COD remained at the setpoint, when the influent COD value or inflow flowrate was changed. The results indicate that reasonable forecasting and control performances were achieved through the developed system; the maximum error was only 3.67%, and the average relative error was 2%.     

高速模糊PID温度控制器的设计与实现

模糊-PID控制器由于其较高的精度与优良的动态响应性能而获得了广泛应用,实现方法多为基于单片机技术的软件实现,其实时性与抗干扰性能并不理想。采用EDA技术,以FPGA为基础,设计了一款硬件模糊-PID控制器,很好地克服了软件实现方案的上述缺点。当采样温度与设定值的差值在一定范围内时,采用经典PID控制以消除系统的动态误差;当差值大于某一范围时,采用模糊控制以获得可靠的控制精度。通过Verilog仿真分析,证明了其上述优点,具有较高的实用价值。     

智能算法在交流调速系统中的研究

提出一种基于遗传算法优化的异步电机参考模型模糊自适应矢量控制调速系统,其异步电机模糊自适应速度辨识机构可根据参考模型输出与被控可调模型输出之差及其变化率,产生一个模糊自适应信号,控制被控可调模型的输出趋于参考模型的输出.仿真和实验表明,该系统具有良好的动态特性,在稳态精度上也优于普通的模型参考自适应系统,为无速度传感器...     

HEDP生产过程的智能控制

本文在分析羟基亚乙基二膦酸(HEDP)生产工艺特点的基础上,提出采用自适应模糊控制策略进行生产过程的智能控制,阐述了自适应模糊控制系统的软件设计。并模拟仿真证明其控制输出能够快速地跟踪设定值,实时控制效果良好。本文对改进现有HEDP生产控制具有参考价值。     

模糊控制在磨矿分级自动控制中的应用研究

针对目前磨机运行过程中随机干扰因素多、过程机理复杂、非线性、大滞后、各环节变量相互耦合作用大等特点,研究一种以模糊控制和PID控制相结合的控制方案。结合工程实际介绍模糊控制的基本原理,通过测量与栽荷紧密相关的磨机电流,采用二维模糊控制器对给矿量设定值进行模糊控制,提出给矿量设定值的控制算法和控制规则。实际应用结果表明,该方法有效地解决了磨机所发生胀肚和欠载的问题,提高了磨机的工作效率和各项工作指标。     

橡胶四辊压延制品厚度Fuzzy控制器设计方法

本文是作者在橡胶四辊压延机覆胶帘布、胶片厚度检测、控制系统改造实际工作中经验的理论总结，扼要介绍了轮胎生产中橡胶制品压延厚度目标值采用模糊（Ｆｕｚｙ）控制策略时控制器的设计要求，以及目标值隶属函数、控制规则数量和质量、模糊运算子的取大、取小及反模糊化等方法的确定。     

Generalization of Takagi-Sugeno Fuzzy Controller and its Application to Control of MMA Batch Polymerization Reactor

In this research a generalization of Takagi-Sugeno fuzzy controllers is presented. In this generalization all or some of the inputs of the fuzzy controllers are fuzzy numbers. Also, it is proved that this generalization is well defined, which means that if the inputs of a generalized Takagi-Sugeno fuzzy controller are singleton fuzzy sets, then the generalized Takagi-Sugeno fuzzy controller will be reduced to a Takagi-Sugeno fuzzy controller. This controller was applied to temperature control of a methyl methacrylate (MMA) batch polymerization reactor, which uses jacket temperature error in addition to reactor temperature error. But the desired jacket temperature is affected by noise and disturbance. Therefore, there is uncertainty in the desired value of this variable. Fuzzy numbers are applied to model this uncertainty and a fuzzy trajectory was achieved for jacket desired temperature. After that an adaptation mechanism was designed. Experimental results present the fine performance of this controller in temperature control of solution polymerization of methyl methacrylate.     

Guaranteed cost distributed fuzzy observer‐based control for a class of nonlinear spatially distributed processes

The guaranteed cost distributed fuzzy (GCDF) observer‐based control design is proposed for a class of nonlinear spatially distributed processes described by first‐order hyperbolic partial differential equations (PDEs). Initially, a T–S fuzzy hyperbolic PDE model is proposed to accurately represent the nonlinear PDE system. Then, based on the fuzzy PDE model, the GCDF observer‐based control design is developed in terms of a set of space‐dependent linear matrix inequalities. In the proposed control scheme, a distributed fuzzy observer is used to estimate the state of the PDE system. The designed fuzzy controller can not only ensure the exponential stability of the closed‐loop PDE system but also provide an upper bound of quadratic cost function. Moreover, a suboptimal fuzzy control design is addressed in the sense of minimizing an upper bound of the cost function. The finite difference method in space and the existing linear matrix inequality optimization techniques are used to approximately solve the suboptimal control design problem. Finally, the proposed design method is applied to the control of a nonisothermal plug‐flow reactor. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2366–2378, 2013