DCS及PLC系统在阿钢中轧加热炉中的应用

主要介绍了DCS及PLC系统在阿城钢铁公司中型轧钢厂蓄热式加热炉中的应用情况,简述了自动控制系统的硬件构成和特点,对蓄热式加热炉的换向过程、炉膛压力和炉膛温度等自动控制过程进行了说明。经过一年多的实际运行,证明控制系统稳定可靠,为蓄热式加热炉稳定运行提供了保障。     

基于PLC的机车空压机性能测控系统研制

以PLC为测控核心单元,建立了压缩机性能测控系统,实现了对压缩机试验台位及驱动系统的选择,压缩机的启动、停机、转速调节、排气压力调节等的控制,以及对压缩机的各个运行参数实时采集和监控;并通过计算机将采集参数进行处理,实时获得压缩机各项性能指标并输出测试报告。该测控系统已成功用于机车用空压机性能实验台上。     

电加热炉测温技术分析

介绍了工业热生产中电加热炉温度控制系统中炉膛温度的检测采集,分析了加热炉工作过程中炉内热交换机理,确定炉膛温度的合理测量位置;介绍热电偶工作原理,并分析了电加热炉中热电偶对炉温测量准确性的影响,列举热电偶测温精度保证措施;在此基础上用LM35DZ半导体温度传感器对热电偶冷端温度进行补偿.     

基于PLC与组态王的轧钢蓄热式加热炉集散控制系统的实现

介绍了如何通过SIEMENS S7-300 PLC与应用组态软件开发的HMI来共同组建轧钢蓄热式加热炉的集散控制系统,该系统实现了温度、压力等参数的监控、阀门自动控制、自动报警、自动记录等功能。     

基于PLC的采暖炉系统的自动控制

本文以单片机STC89C52RC、DS1302时钟芯片、DS18B20温度传感器构成.选取炉出口温度位主被控参数,选取炉膛温度为副被控参数,把炉出口温度调节器的输出作为炉膛温度调节器的给定值.控制部分采用PID算法,经过PID运算产生的控制信号是数字信号,将其送入D/A转换,最终实现对炉温的高精度控制.     

PLC在天然气调压站自动控制系统中的应用研究

在简单介绍天然气调压站工作原理的基础上,详细讨论了用PLC实现天然气调压站自动控制系统的设计.系统通过实时监测调压站关键部位的压力、压差、阀位和流量等主要参数,及时反映调压站的实际工作状况,并作用于执行机构进行调整,确保供气系统安全稳定的工作.系统可以通过本地触摸屏和远程网络两种方式进行实时监控,并为上位机预留了标准的Modbus通信接口,便于系统远程网络化控制管理.     

加热炉自学习反馈控制系统设计

针对加热炉热工参数的手动或自动调节是基于人为直接参与或传感器感知,由调节器和执行器实现参数自动调节,都是直接或间接在人为参与下完成,易造成失误偏差,利用计算机控制技术,对热工参数系统进行自动控制设计,实现了加热炉在燃耗最低、效率最高工况下生产率的最大化。实验结果表明,计算机控制系统明显优越于传统自动调节系统。     

基于欧姆龙PLC的ABS气压电磁调节器试验装置

介绍了基于欧姆龙PLC搭建的ABS气压电磁调节器试验装置和计算机采集系统。具体阐述了响应特性、调节功能和工作耐久性等项目检测的具体实现方法,实践结果表明该试验装置运行稳定,控制精准,数据采集实时,满足QC/T 1006-2015《汽车防抱制动系统气压电磁调节器性能要求及台架试验方法》和企业技术条件的相关要求。     

热交换站监控系统的设计

详细介绍了热交换站计算机自动监控系统的设计,选择西门子200PLC为控制器,实现对热交换站温度和压力的自动控制,提出了本系统的温度压力控制方案,并就供水压力控制方面,详细介绍了PLC结合变频器的节能控制实现过程。此外,基于MCGS组态软件设计上位监控,实现对现场数据的实时采集和远程控制。     

再加热炉电气控制与通讯系统设计

针对江苏常宝普莱森钢管有限公司再加热炉的生产工艺要求,结合公司的现场实际生产情况,对再加热炉电气控制与通讯系统进行改造设计.用PLC控制器代替原先的继电器回路;采用基于现场总线PROFIBUS基础上的控制方案,通过组态王软件实现对生产系统的模拟与实时监控功能.提高了控制系统的准确性与可靠性,优化了系统性能.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.