Waters高效液相色谱仪柱温箱故障分析与维修1例

温控系统由温控器及柱温箱组成,是Waters高效液相色谱仪重要的组成部件.在设定温度下,温控系统可以避免柱温受外界的影响,从而保持柱温恒定对保证分析结果的重复性、准确性有非常重要的作用.通过对柱.温箱故障现象及其控制电路的分析,确定故障原因为固态继电器损坏,更换相应继电器,故障消除.     

台达DTE智能型多路模块温控器

台达电子集团DTE智能型多路温控器的主机可提供最多8路温控功能，每路温控均可独立运作。主机通过扩展7台DTC2000，最多可得到15路温控通道。DTE输入模块与输出模块都可灵活插拔。DTE模块支持不同类型的温度传感器及继电器、固态继电器和模拟量I／O模块。     

智能电加热温控系统的研制

智能电加熟温控系统采用单片机作为控制器，采用PWM调节方法平滑调节温度，克服手动调节产生的过冲现象，达到节电和舒适的效果。智能电加热温控系统还用可控硅取代继电器作为电子开关，电路白勺通断均在电流的过零点实现，降低了电磁干扰．减小了电源对器件的冲击作用，增加了系统的可靠性。使用该系统。用户可根据自己的习惯将不同的时间段设置成相应的温度，系统使依照设定值自动调节室内的温度，实现温度智能化控制。     

四管制风机盘管电气控制系统设计与安装

结合武汉国际博览中心洲际酒店中央空调系统的组成及运行原理,介绍四管制风机盘管的电气控制系统设计与安装。根据四管制风机盘管性能及其回水管上的电动调节阀的工作原理进行控制系统设备选型,设备主要包含液晶温控面板及中间继电器。该控制系统可实现风机盘管及电动调节阀的协调运行,调节室内温度,从而满足用户需求。     

基于BPNN的玻璃烧结炉控制系统的设计与应用

针对彩色平板玻璃生产工艺的需要,研制开发了一种能18路精确控温的玻璃烧结炉温控系统.该温控系统由PLC、上位机、触摸屏、固态继电器、风机等部分组成.在该系统中设计实现了基于BP神经网络的自适应神经形态自校正PID控制器,利用输出误差,即当前时刻参考值和对象输出的差值,作为学习信号,供BPNN去调节PID控制器的参数.在运行过程中,系统能精确控制窑炉18路温度按照升降温曲线进行变化,从而实现生产工艺的要求.     

基于PLC的热泵式温控箱控制系统设计

根据热泵式温控箱的组成形式及工作方式设计了温控箱的控制系统。系统以台达PLC作为主控制器,分别对温度采集器、电磁阀、水泵、热泵等进行控制,能够准确的读取各温控箱的温度,对各温控箱进行温度控制;系统配备友好的人机界面,实现人机互通。控制系统使整个温控箱系统按照人为设定有序的运行,且运行可靠、操作方便,为热泵式温控箱进一步研究提供基础。     

基于CAN-bus的分布式电阻炉智能温控系统的设计

文中设计的基于CAN-bus的分布式智能电阻炉温控系统,采用专用芯片AD595和AD538,实现了对炉温信号精确测量;采用改进的积分分离PID控制算法,通过输出的PWM信号控制固态继电器的导通时间,实现了对电阻炉炉温的智能化控制,并通过CAN-bus与上位管理机进行通信,解决了传统模拟分离式温控仪表的问题。结果表明:系统具有超调小、控制精度高、抗干扰性强、运行稳定等优点,具有较好的应用前景。     

一种保温隔热型材检测环境温控调节系统的设计

保温隔热型材检测环境温控调节系统属于温控应用技术领域。针对保温隔热型材检测存在的问题,提出了一种保温隔热型材检测环境温控调节系统,解决了现有空调检测环境无法实现规范要求偏差范围内进行环境温控调节的问题。     

计算机技术在Zwick温控系统改造上的应用

着重论述了计算机技术在Zwick温控系统改造上的应用,详细阐述了Zwick温控系统改造的硬件设计和软件设计。经过多次试验验证,采用计算机技术改造后的温控系统能真实测量试样温度,试样温度自动趋向并稳定在试验设定的温度,符合试验要求。     

磁保持继电器机械寿命试验控制系统的设计

根据机械寿命试验的原理及影响磁保持继电器寿命的各种因素,考虑硬件的电路系统和相关应用软件的不同目标,设计了磁保持继电器机械寿命试验系统.该系统可同时对多个继电器进行试验,能够提供有效、快速的试验系统检测继电器机械寿命,系统稳定运行,保证了继电器的质量.     

基于AT89C51单片机的工业冷水机控制系统

以工业用冷水机为控制对象,探讨了一种基于单片机AT89C51的控制器的硬件组成及软件实现方法。该控制器集温度调节、高低电压报警、水位监测等功能于一体,成本低,性能稳定,有较高推广价值。     

塑料微流控芯片热压成形温度控制装置

采用聚合物如塑料等制作微流控芯片是拓展芯片应用,实现芯片产业化的关键。温度是塑料微流控芯片热压成形过程中的重要工艺参数。本文采用半导体热电致冷堆,设计了适合塑料芯片制作的温度控制装置;分析了升降温过程中所需的加热／制冷功率,并对升降温特性进行了研究;设计了半导体热电致冷堆供电电源装置。对温度控制装置的升／降温及温度控制精度进行了实验,并给出了实验结果。     

Parameter estimation of integrating and time delay processes using single relay feedback test

Autotuning using relay feedback is widely used to identify low order integrating plus dead time (IPDT) systems as the method is simple and is operated in closed-loop without interrupting the production process. Oscillatory responses from the process due to ideal relay input are collected to calculate ultimate properties of the system that in turn are used to model the responses as functions of system model parameters. These theoretical models of relay response are validated. After adjusting the phase shift, input and output responses are used to find land mark points that are used to formulate algorithms for parameter estimation of the process model. The method is even applicable to distorted relay responses due to load disturbance or measurement noise. Closed-loop simulations are carried out using model based control strategy and performances are calculated.     

基于PLC的数控刀片刃磨机床控制系统设计

PLC是一种新型的工业自动化控制装置,由于具有很高的可靠性和使用灵活性,PLC控制系统正在大量地替代传统的继电-接触控制系统.本文用PLC代替传统继电器,对数控刀片刃磨机床进行了自动化改造,详细介绍了控制系统的设计方案,井给出了相应的电气控制原理图和PLC梯形图程序.     

基于DSP的超高压线路微机保护装置的研究

随着我国电网容量的迅速增加和电压等级的不断提高,对超高压输电线路保护系统的性能提出了更高的要求。该保护系统以TMS320F2812为核心硬件平台,设有电流差动保护为主体的快速主保护。由工频变化量阻抗元件构成的快速Ⅰ段距离保护。相对于传统的线路保护系统在功能上有了较大的扩展。     

Principles of designing adaptive relay systems for stratospheric power transmission

Problems of designing laser power transmission systems in a turbulent atmosphere using relay mirrors mounted on a stratospheric airship are analyzed. It is shown that such a system can be designed using a high-power ground-based ytterbium fiber laser, relay mirrors for transmitting highpower laser radiation, and an adaptive optical system for correcting the phase distortions of laser beams due to atmospheric turbulence. A model of a laser power transmission system was designed and tested under laboratory conditions; the tests confirmed the possibility of correcting atmospheric-turbulence distortions during guiding and high-accuracy stabilization of laser beams.     

可控气氛多用途精密电热炉设计

应用环保设计思想，进行了一种可控气氛多用途精密电热炉的设计。通过炉体结构和加热温控系统的优化，达到良好的温度均匀性、温控精度和工作安全性，可控的工作气氛特别适合于对热敏性、易分解氧化物质和复杂成分物品进行快速高效的加工处理，并在行业生产中获得应用。     

Robust on-line relay automatic tuning of PID control systems

In this paper, a robust on-line relay automatic tuning method for PID control systems is developed which expand on the application domain of Astrom's renowned relay autotuning method. In the proposed configuration, a relay is applied to an inner loop of a controller-stabilised process in the usual manner. Using the induced limit cycle oscillations from the closed-loop system, the controller settings may be re-tuned non-iteratively to achieve enhanced performance without disrupting closed-loop control. Two control tuning methodologies are developed -- a direct and an indirect method based on an explicit process model. Simulation examples and a real-time experiment are provided to illustrate the practical appeal and potential advantages of the proposed method over the basic one.     

强湍流下并行中继自由空间光通信的中断分析

在大气强湍流条件下,对并行中继自由空间光通信系统的中断概率进行了研究.考虑大气衰减、大气湍流和指向误差对自由空间光通信系统传输性能的影响,建立了自由空间光通信系统的复合信道模型.基于此信道模型,推导了并行中继自由空间光通信系统端到端中断概率的解析表达式.最后,通过计算机仿真分析了发送功率、指向误差及通信距离对通信系统中断概率的影响.仿真结果表明,并行中继传输技术可以有效提高自由空间光通信系统的中断性能.此外,所推导中断概率的解析表达式可准确地评估并行中继自由空间光通信系统的传输性能,为未来自由空间光通信系统的设计提供理论依据.     

Modeling and control of non-square MIMO system using relay feedback

This paper proposes a systematic approach for the modeling and control of non-square MIMO systems in time domain using relay feedback. Conventionally, modeling, selection of the control configuration and controller design of non-square MIMO systems are performed using input/output information of direct loop, while the output of undesired responses that bears valuable information on interaction among the loops are not considered. However, in this paper, the undesired response obtained from relay feedback test is also taken into consideration to extract the information about the interaction between the loops. The studies are performed on an Air Path Scheme of Turbocharged Diesel Engine (APSTDE) model, which is a typical non-square MIMO system, with input and output variables being 3 and 2 respectively. From the relay test response, the generalized analytical expressions are derived and these analytical expressions are used to estimate unknown system parameters and also to evaluate interaction measures. The interaction is analyzed by using Block Relative Gain (BRG) method. The model thus identified is later used to design appropriate controller to carry out closed loop studies. Closed loop simulation studies were performed for both servo and regulatory operations. Integral of Squared Error (ISE) performance criterion is employed to quantitatively evaluate performance of the proposed scheme. The usefulness of the proposed method is demonstrated on a lab-scale Two-Tank Cylindrical Interacting System (TTCIS), which is configured as a non-square system.