THE EFFECT OF OPERATING VARIABLES ON THE DYNAMICS OF CATALYTIC CRACKING PROCESSES

The dynamic Characteristics of a Fluidized Catalytic Cracking Process are examined over a wide range of operating conditions. A novel Order of Magnitude Approach is introduced to successfully provide physical insight into the cause and effect relationship between operating conditions and dynamic characteristics. It is shown that the original five-dimensional dynamic model is characterized by three fast time constants and two slow ones that dominate the dynamic responses. The two most important time constants are expressed as explicit functions of the operating conditions. These formulas correctly indicate in which parameter regions the open loop response is oscillatory (underdamped) or nonoscillatory (overdamped). Extensive process variables, that are either flow or capacity, related are defined in order to provide an approximate physical meaning for the dynamic modes of the system. It is shown that the two slow modes of the process are related to the enthalpy content of the regenerator and the sensible heat content of the catalyst phase in both the reactor and regenerator.     

格灵化工基于SmartPro的DCS系统设计与应用

介绍北京和利时公司开发的SmartPro MACS Ⅲ型DCS系统在格灵化工硫酸装置中的应用.DCS系统包括硬件组成、软件设计及控制功能实现.该控制系统稳定可靠、控制精度高.在提高生产装置自动化水平的同时,使硫酸产品质量提高,生产成本大幅度降低.     

浅谈我公司0.6mm超薄浮法玻璃生产

我公司在成功生产出1.1mm超薄浮法玻璃的基础上,又对原料、熔化、成型、退火等影响超薄玻璃质量的各种因素进行了全方位的技术攻关,成功生产出0.6mm超薄浮法玻璃,填补了国内空白.     

甲胺基阿维菌素苯甲酸盐等对棉铃虫的室内毒力评价

采用微量点滴和夹毒叶片法测定了甲胺基阿维菌素苯甲酸盐等几种杀虫剂对棉铃虫的触杀及胃毒毒力，又采用了虫体浸渍法和食叶浸渍法测定了其对棉铃虫的室内防盗。甲胺基阿维菌素苯甲酸盐对棉铃虫有着极高的胃毒毒力，其LC50为1．0086mg/L。     

溴氟菊酯防治大豆食心虫,大豆蚜,甘蓝夜蛾试验

１９９２～１９９５年用１０％溴氟菊酯乳油对大豆食心虫、大豆蚜、甘蓝夜蛾进行了小区试验。结果表明，该药对上述三种害虫具有良好的防效。ｌ０００倍液对大豆食心虫防治效果与２０％甲氰菊酯乳油２０００倍液相当，达到３９２．９％以上；用１０００～２０００倍液防治大豆蚜，药后７天防效达８８．５％以上；用５００～１５００倍液防治甘蓝夜蛾，药后７天均达到了８４．６％以上的防治效果。而且对作物安全。     

用DCS顺控实现电除尘自动控制

介绍一种对电除尘工序进行远程自动控制的方法。使用DCS顺序控制图，通过模块组态和内部编程，实现多台设备的自动控制，优化工艺过程，提高该工序的自动化水平。     

Nonlinear multiobjective model-predictive control scheme for wastewater treatment process

A nonlinear multiobjective model-predictive control (NMMPC) scheme, consisting of self-organizing radial basis function (SORBF) neural network prediction and multiobjective gradient optimization, is proposed for wastewater treatment process (WWTP) in this paper. The proposed NMMPC comprises a SORBF neural network identifier and a multiple objectives controller via the multi-gradient method (MGM). The SORBF neural network with concurrent structure and parameter learning is developed as a model identifier for approximating on-line the states of WWTP. Then, this NMMPC optimizes the multiple objectives under different operating functions, where all the objectives are minimized simultaneously. The solution of optimal control is based on the MGM which can shorten the solution time. Moreover, the stability and control performance of the closed-loop control system are well studied. Numerical simulations reveal that the proposed control strategy gives satisfactory tracking and disturbance rejection performance for WWTP. Experimental results show the efficacy of the proposed method.     

A virtual actuator and sensor approach for fault tolerant control of LPV systems

In this paper, a fault tolerant control (FTC) strategy using virtual actuators and sensors for linear parameter varying (LPV) systems is proposed. The main idea of this FTC method, initially developed for LTI systems, is to reconfigure the control loop such that the nominal controller could still be used without need of retuning it. The plant with the faulty actuator/sensor is modified adding the virtual actuator/sensor block that masks the actuator/sensor fault. The suggested technique is an active FTC strategy that reconfigures the virtual actuator/sensor on-line taking into account faults and operating point changes. The stability of the reconfigured control loop is guaranteed if the faulty plant is stabilizable/detectable. The LPV virtual actuator/sensor is designed using polytopic LPV techniques and linear matrix inequalities (LMIs). A two-tank system simulator is used to assess the performance of the proposed method. In particular, it is shown that the application of the proposed technique results in an improvement, in terms of performance, with respect to the LTI counterpart.     

Customizable hardware design of fuzzy controllers applied to autonomous car driving

Nowadays, final products often encompass a certain intelligence therein to deal with variation or lack of precision in the sensing input data. This intelligence is usually acquired via the utilization of existing soft techniques, such as artificial neural networks, genetic algorithms and fuzzy control, among others. Thus, it is profitable to have on-the-shelf shell scalable and adaptive hardware designs that implement these soft techniques. This availability allows for an immediate embedding of any of those designs onto final products. This usually entails a reduced time-to-market of the product. Process control is one of the many applications that took advantage of the fuzzy paradigm. In general, controllers are embedded into the controlled device. This paper presents a novel design of a reconfigurable efficient parallel architecture to implement fuzzy controllers on hardware with almost no design effort for final users. The proposed architecture is herein proven suitable for embedding. It is customizable, so it allows the setup and configuration of the controller parameters, and hence its use for any problem application. Two fuzzy controllers that model autonomous car driving are implemented and their cost and performance evaluated.