智能化和网络化

发达国家的挤出机已普遍采用现代电子和计算机控制技术，对整个挤出过程的工艺参数如熔体压力及温度、各段机身温度、主螺杆和喂料螺杆转速、喂料量，各种原料的配比，电机的电流、电压等参数进行在线检测，并采用微机闭环控制。有的公司已采用网上远程监测、诊断和控制，对挤出成型生产线进行网络控制。     

含盐溶液汽液平衡预测(Ⅱ)参数的物理意义及估算

本文讨论了笔者(Ⅰ)报提出的简化Pitzer(1980)模型中单参数的物理意义,发现该参数与水化数成正比,据此得出由离子半径预测单参数的关联式.最后预测了373.15K电解质水溶液的过量焓,从而在理论上验证了该单参数与温度的关系.     

基于正交实验的薄壁塑件翘曲变形模拟分析

以薄壁塑件为对象,研究了模具温度、熔体温度、保压时间及注射压力等工艺参数对该薄壁塑件成型翘曲的影响规律,并用正交实验法优化成型工艺方案,获得最小的翘曲塑件.结果表明,熔体温度和保压时间对塑件翘曲变形影响较为显著,模具温度对塑件翘曲基本没有显著的影响.     

玻纤/环氧复合材料力学性能和界面参数的实验研究

本文对玻璃纤维增强环氧树脂基复合材料的力学性能,包括刚度、强度、横截面内的油松比以及界面参数作了较为详细的实验研究。着重研究试件制作过程中温度和压力以及它们的维持时间对各种性能参数的影响。界面参数的计算采用Hashin在1990年提出的一种自洽模型。     

DNMR法测量分子内转动动力学活化参数

讨论了如何用 DNMR法测量分子内转动动力学的活化参数 ,如活化焓变化和活化自由能变化等参数。实验结果表明要想用 DNMR法得到较为可靠的分子内转动动力学活化参数 ,必须在较宽的温度范围内用诸如完全线形拟合法、自旋磁化强度迁移法和自旋锁定技术等具体的 DNMR实验技术在不同的温度范围内测得分子内转动的速率参数。     

复合材料热压机结构与控制设计

复合材料经热压固化后成型,热压过程中的工艺参数如温度、压力是复合材料成型的两个重要参数,针对这两个工艺参数设计了热压机总体结构,包括夹紧结构、翻转结构、加热加压结构等,介绍了其工作原理和设计特点.控制部分采用PLC控制电磁比例阀调节液油油压、油缸位置,对温度进行模糊自整定PID闭环控制,绘制出控制总体流程图.实验结果证明,复合材料构件压力、温度等能够满足工艺要求.     

固定床反应器的飞温和参数敏感性

以参数敏感性定义作为理论基础和数学依据,证明了热点轨迹拐点是反应系统的参数敏感点,从理论上给出了固定床反应器采用一维拟均相模型,进行一级反应,冷却介质温度不变,且与物料入口温度相等时,反应系统安全操作所允许的温度上限,并利用临界操作曲线热点和超临界操作曲线拐点之间的关系,推导出反应系统安全操作的临界判据,该关联式与El-Swai等人的实验结果吻合很好.     

固定床反应器的飞温和参数敏感性

以参数敏感性定义作为理论基础和数学依据,证明了热点轨迹拐点是反应系统的参数敏感点,从理论上给出了固定床反应器采用一维拟均相模型,进行一级反应,冷却介质温度不变,且与物料入口温度相等时,反应系统安全操作所允许的温度上限,并利用临界操作曲线热点和超临界操作曲线拐点之间的关系,推导出反应系统安全操作的临界判据,该关联式与El-Swai等人的实验结果吻合很好.     

玻璃钢复合材料受热状态物性参数变化研究

玻璃钢复合材料主要成分为玻璃纤维和树脂,其制品在受热状态下会发生复杂的物理化学变化,相应的物性参数也随之会有较大变化,进而影响材料结构内部的温度分布;对其受热状态下的变化过程进行研究,给出相应的物性参数变化模型;制备玻璃钢试样进行风洞条件下的烧蚀试验,测量试样背面温升,与应用物性参数变化模型进行的仿真计算结果较为吻合,表明模型构建符合工程实际.     

缠绕管中结晶结垢的模拟研究

利用CFD模拟探究了缠绕管结构参数与操作参数对管内结垢的影响。结果表明,在相同的传热面积下,缠绕直径越小,传热效率越高,管内流体温度更高,管内更容易形成污垢。管径越小,管壁温度越容易传递到管内流体,管内更容易形成污垢。而缠绕角度则不会影响管内的结垢规律。与直管相比,当换热面积相同且恒定壁温或恒定热流时,缠绕管内流体温度较高,结垢率更大。当换热面积和换热量相同时,缠绕管内结垢率更小。     

铜精炼过程铜液温度软测量模型及应用

为了解决铜精炼过程中高温铜液温度的测量难题,确保铜精炼过程的阳极铜产品质量,基于铜精炼过程中不同阶段的热工机理,分别建立了保温过程、氧化过程以及还原过程的高温铜液温度的机理软测量模型,并采用数据预处理、黄金分割法搜索区间及其函数链神经网络校正等技术对其进行了算法设计以及编程实现.实际应用结果表明,铜精炼过程铜液温度软测量可以反映铜精炼过程铜液温度的真实变化,有助于实现铜精炼过程铜液温度软控制以及提高铜精炼过程的生产效率和生产质量.     

Consensus-based approach for parameter and state estimation of agro-hydrological systems

The development of advanced closed-loop irrigation systems requires accurate soil moisture information. In this work, we address the problem of soil moisture estimation for the agro-hydrological systems in a robust and reliable manner. A nonlinear state-space model is established based on the discretization of the Richards equation to describe the dynamics of the agro-hydrological systems. We consider that model parameters are unknown and need to be estimated together with the states simultaneously. We propose a consensus-based estimation mechanism, which comprises two main parts: (a) a distributed extended Kalman filtering algorithm used to estimate several model parameters; and (b) a distributed moving horizon estimation algorithm used to estimate the state variables and one remaining model parameter. Extensive simulations are conducted, and comparisons with existing methods are made to demonstrate the effectiveness and superiority of the proposed approach. In particular, the proposed approach can provide accurate soil moisture estimate even when poor initial guesses of the parameters and the states are used, which can be challenging to be handled using existing algorithms.     

大型燃气热浸镀锌炉

研制设计的大型气热浸镀锌炉,采用以对流为主、辐射为辅的锌锅加热方式,有效地降低了锌锅侧面烟气温度,延长了锌锅的使用寿命;同时以脉冲燃烧为主要控制方式的闭环温度控制系统的成功应用,使锌液温度控制稳定、安全、可靠、产品质量得到了可靠保证。     

基于单片机80C51的加热炉模糊PID控制器设计

对于加热炉温度控制系统,采用传统的接触器控制已不能满足复杂工艺的控制要求。提出基于单片机的模糊PID电热炉控制器,根据炉温情况和工艺的要求,调整控制系统相应PID参数,满足快速动态响应的要求。仿真实验表明基于电热炉模糊PID温度控制超调量小、响应速度快,解决了电热炉系统智能控制问题。     

基于自适应神经模糊推理系统的间歇反应精馏组分估算(英文)

Composition estimation plays very important role in plant operation and control. Extended Kalman filter (EKF) is one of the most common estimators, which has been used in composition estimation of reactive batch distillation, but its performance is heavily dependent on the thermodynamic modeling of vapor-liquid equilibrium, which is difficult to initialize and tune. In this paper an inferential state estimation scheme based on adaptive neuro-fuzzy inference system (ANFIS), which is a model base estimator, is employed for composition estimation by using temperature measurements in multicomponent reactive batch distillation. The state estimator is supported by data from a complete dynamic model that includes component and energy balance equations accompanied with thermodynamic relations and reaction kinetics. The mathematical model is verified by pilot plant data. The simulation results show that the ANFIS estimator provides reliable and accurate estimation for component concentrations in reactive batch distillation. The estimated states form a basis for improving the performance of reactive batch distillation either through decision making of an operator or through an automatic closed-loop control scheme.     

内窥式热像仪在玻璃熔窑中的应用

介绍了内窥式热像仪的特点和技术参数。通过在我司某条浮法玻璃熔窑安装试用内窥式热像仪后,证明其能够实现熔窑内玻璃液温度测量控制、熔化工艺监控、熔窑保护和节能减排等功效,可以在浮法玻璃熔窑监控中推广应用。     

Outlet Temperature Correlation and Prediction of Transfer Line Exchanger in an Industrial Steam Ethylene Cracking Process

Predicting the best shutdown time of a steam ethylene cracking furnace in industrial practice remains a challenge due to the complex coking process. As well known, the shutdown time of a furnace is mainly determined by coking condition of the transfer line exchangers （TLE） when naphtha or other heavy hydrocarbon feedstocks are cracked. In practice, it is difficult to measure the coke thickness in TLE through experimental method in the complex industrial situation. However, the outlet temperature of TLE （TLEOT） can indirectly characterize the coking situation in TLE since the coke accumulation in TLE has great influence on TLEOT. Thus, the TLEOT could be a critical factor in deciding when to shut down the furnace to decoke. To predict the TLEOT, a paramewic model was proposed in this work, based on theoretical analysis, mathematic reduction, and parameters estimation. The feasibility of the proposed model was further checked through industrial data and good agreements between model prediction and industrial data with maximum deviation 2% were observed.     

Disturbance rejection of dead-time processes using disturbance observer and model predictive control

This article mainly focuses on disturbance rejection of dead-time processes by integrating a modified disturbance observer (MDOB) with a model predictive controller (MPC). The effect caused by model mismatches is regarded as a part of the lumped disturbances. This means that the disturbances considered here include not only external disturbances, but also internal disturbances caused by model mismatches. Control structure of the proposed method includes two parts which can be designed separately. The MPC which acts as a prefilter, is employed to generate appropriate control actions such that a desired setpoint tracking response is achieved. The MDOB is employed to estimate the disturbances of the closed-loop system, and the estimation is used for feedforward compensation design to reject disturbances. Rigorous analysis of setpoint tracking and disturbance rejection properties of the closed-loop system are given in the presence of both model mismatches and external disturbances. The proposed scheme is applied to control the temperature of a simplified jacketed stirred tank heater (JSTH). Simulation results demonstrate that the proposed method possesses a better disturbance rejection performance than those of the MDOB-PI, MPC and PI methods in controlling such dead-time processes.     

石灰石煅烧分解率在线监测模型

基于石灰炉热衡算和物料衡算原理 ,在现场可测参数的基础上 ,导出了石灰石煅烧分解率的在线监测模型 .将其应用于某厂Φ4m× 2 1m的生产实际中 ,利用实测数据对模型进行了检验 ,证明模型计算结果与现场实测结果能很好地吻合 ,具有较好的实用价值 .该模型的建立可为石灰炉的炉况诊断与操作优化以及自动检测和控制提供有力的技术支持     

传递过程原理在移动床中的应用——(Ⅰ)高炉煤粉喷吹数学模型

炼铁高炉是移动床工艺用于固相加工的重要特殊例子.根据物料和热的微分平衡,对高炉风口喷吹煤粉时所发生的传递现象和化学反应进行了解析.本文中数学模型的理论计算值和实际高炉的实测结果的一致性证明了模型的可靠性.本文提供的软件具有通用性,只要输入不同高炉的鼓风条件、燃料喷吹量、风口直径等初始参数,就可以预报任一参数的变更对炉内状况(诸如炉内气体组分、温度、诸反应速率、回旋区深度、置换比等)的影响,由此不仅可判断高炉内的燃烧状况,而且为高炉操作选择合适的鼓风参数及喷煤量提供了计算方法,以便控制高炉内气流分布和炉温,使高炉操作正常.