变频器调速控制接线方式的选择和应用

在石油、石化、煤液（气）化等装置中部分机组驱动电动机需要通过变频器调速控制,变频器有低压、中压变频器,接线方式也比较多,按照工艺对控制设备的可靠性要求,参照投资成本,选择最佳控制接线方式尤为重要,本文介绍四种比较典型的变频器调速控制接线方式。     

VACON变频器在桥式起重机上的应用

山东鲁南水泥有限责任公司采用典型继电器、接触器控制模式的粘土吊车,运行中故障频繁,既增大维护和生产成本,还影响系统生产运行。为此,该公司成功地将VACON CXS调速变频器运用到粘土吊钩控制系统。同时,通过修改吊车变频器内最小频率、减速时间等参数,有效地避免了“溜钩”现象;通过对开闭电机、提升电机进行硬件连接、软件调整及设置最高频率,保证了开闭2台电机之间的速度平衡和力矩平衡,从而有效地防止了“飞车”事故。经改造和一段时间的调试,该粘土吊车实现了低故障、低能耗的稳定运行。     

低压变频器的运行与管理

介绍变频器设计和选型、安装和接线、运行和维护及故障处理等方面的经验。     

变频器常见故障分析及处理

针对变频器的常见故障,结合多年运行实践及维修经验,分析了变频器常见故障的原因,提出了处理措施,并通过一个变频器故障实例,说明了变频器故障处理的步骤和应注意事项。     

变频器综合检测平台

随着数字化油田的建设,全厂范围内投入使用的变频器数量不断增长。经过长时间运行,变频器故障次数、故障率正在逐年上升,导致站库与单井正常生产受到严重影响。变频器主要通过查找故障代码或断电后逐一检测电路的方式进行故障鉴定,但使用万用表等常规工具无法查出隐性故障,修复不久后又出现故障导致"二次维修"。另外,待测变频器在维修以后难以判断其性能是否达到工况要求,必须在站库、井场反复测试,影响维修效率和运行时率。为解决上述问题,开展变频器综合检测平台研究,准确判断、排查变频器故障原因与隐患,缩短维修周期。     

基于 ACS2000 DFE 中压变频器的 PTA搅拌器传动系统改造

介绍了 ACS2000 DFE 中压变频器的拓扑结构、电源配置、控制系统构成、电平输出原理及直接转矩控制。阐述了在 PTA 搅拌器传动系统改造中,ACS2000 DFE 中压变频器一键自动起停、速度切换及调节、报警及故障输出、运行状态监测的参数及接线设计。通过对 ACS2000 DFE 中压变频器的外部报警及联锁设计分析,提出了外部联锁变更的参考方案。     

浅析油田变频器故障原因及维护建议

变频器广泛的应用在油田生产中,其运行时率及使用寿命将直接影响油田生产管理和生产过程控制。本文通过对变频器故障原因进行分析,根据故障的相关因素提出基层保养维护建议,以延长变频器的使用寿命,降低故障率。     

石化企业变频器的应用

介绍变频器日常运行特点和注意事项,分析变频器的几种故障原因,提出改进措施,通过统计和计算说明变频器的节能效果.     

一起变频器直流母线过电压故障原因分析

某炼化企业2#焦化装置变电站发生0.4kV低压母线“电压异常”告警,造成该段母线所有变频器回路跳闸停机,进而导致装置加热炉A炉生产波动。通过现场变频器报警信息、鼓风机变频器原理图及现场谐波采集等方式对本次故障原因进行分析,针对跳闸根本原因制订整改方案。同时针对辖区其他类似设备举一反三,消除了该类隐患。     

基于Modbus-RTU通讯的工业触摸屏与变频器控制系统

为实现设备的自动化运转,控制系统一般由触摸屏、可编程逻辑控制器(PLC)及模块、变频器和辅助器件等组成。这种控制方式抗干扰能力差、采集运行信号少、响应速度和精度差、接线复杂、电器成本高、对开发设计和调试人员在技术方面有较高要求,并且在系统发生故障时不能快速定位故障点。为提高抗干扰能力、实现更简洁的控制、进一步提高响应速度和精度,用工业触摸屏通过Modbus通讯方式直接控制、采集运行数据并监控变频器的运行,达到相同控制效果下简化设计、提高自动化的目的。     

Hollow fiber membrane contactor as a gas-liquid model contactor

Microporous hollow fiber gas-liquid membrane contactors have a fixed and well-defined gas-liquid interfacial area. The liquid flow through the hollow fiber is laminar, thus the liquid side hydrodynamics are well known. This allows the accurate calculation of the fiber side physical mass transfer coefficient from first principles. Moreover, in the case of gas-liquid membrane contactor, the gas-liquid exposure time can be varied easily and independently without disturbing the gas-liquid interfacial area. These features of the hollow fiber membrane contactor make it very suitable as a gas-liquid model contactor and offer numerous advantages over the conventional model contactors. The applicability and the limitations of this novel model contactor for the determination of physico-chemical properties of non-reactive and reactive gas-liquid systems are investigated in the present work. Absorption of CO₂ into water and into aqueous NaOH solutions are chosen as model systems to determine the physico-chemical properties for non-reactive and reactive conditions, respectively. The experimental findings for these systems show that a hollow fiber membrane contactor can be used successfully as a model contactor for the determination of various gas-liquid physico-chemical properties. Moreover, since the membrane contactor facilitates indirect contact between the two phases, the application of hollow fiber model contactor can possibly be extended to liquid-liquid systems and/or heterogeneous catalyzed gas-liquid systems.     

CFD simulations and particle image velocimetry measurements in an industrial scale rotating disc contactor

Fluid dynamics of the single‐phase and two‐phase flow in a segment of a rotating disc contactor (RDC) liquid–liquid extraction column with 450 mm inner diameter were studied by performing computational fluid dynamics (CFD) simulations and particle image velocimetry (PIV) measurements. The fluid dynamics were investigated to test the predictivity of CFD at industrial scale. Different turbulence models in conjunction with the Eulerian approach were applied in the single‐phase and two‐phase simulations. The turbulent flow characteristics were analyzed by PIV measurements to validate the CFD simulations. An iso‐optical system composed of CaCl₂/water–butylacetate allows for the two‐phase PIV measurements. Local turbulent energy dissipation was derived from velocity gradients in PIV data. In this connection, the influence of the PIV spatial resolution on the measured energy dissipation was also analyzed, and different fit functions were tested to scale the measured energy dissipation. Simulated velocity fields as well as the energy dissipation were compared with the experimental PIV data. The results from the simulations and experiments are in good agreement. The work shows that CFD can predict hydrodynamic characteristics even at bigger scales but is still subject to some minor restrictions. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

溶聚丁苯胶牌号切换对轮胎硫化缺胶的影响

试验研究锦湖SOL 6270M替换独山子RC2557S在轮胎胎面胶体系中的应用效果。研究表明,在半钢子午线轮胎胎面体系中,以SOL 6270M等量替换RC2557S,若保证胎面体系门尼流变等加工性能,则胎面体系流动性下降,引起胎面接头缺胶。     

抗晃电交流接触器在阴、阳极液泵供电回路中的应用

介绍了抗晃电交流接触器及其在阴阳极液泵供电回路中的应用,为解决晃电导致的离子膜跳闸问题提供参考。     

Evaluation of Annular Centrifugal Contactors for the Extraction of Acetic Acid from Aqueous Streams

This study investigates the use of annular centrifugal contactors for the liquid-liquid extraction of acetic acid from an acidic aqueous phase into an organic phase consisting of 1.5 M Tributyl Phosphate in n-Dodecane. Initial break time tests were performed in order to investigate the mixing/separation viability of the organic/aqueous system, and after determining that centrifugal contactors could be used to perform the liquid-liquid extraction, hydraulic tests established the combination of rotation rate and throughput which should be used to ensure proper separation of the two outlet phases. Finally, extraction efficiency data was collected to examine the system conditions that provided the most efficient removal of acetic acid.     

Fluid dynamics of a fluidized-moving bed (flumov)

The fluid dynamics and other features of a gas-solid contactor based on a combination of FLUidized and MOVing beds (flumov) were studied. The fluidized zone is below the moving one; the mov/flu diameter ratio ranges between 2 and 3. The two zones are joined by means of a conical part and no mechanical elements are used between the bottom of the moving bed and the top of the fluidized bed. The gas is fed at the bottom of the fluidized bed; the solid is fed at the top of the moving bed and, consequently, it moves in countercurrent to the gas and in a continuous mode. The adequate regime is reached when a stable vault between the bottom of the moving bed and the top of the fluidized bed is formed and maintained. The solid circulation from the moving to the fluidized bed is controlled by injecting air pulses from the bottom of the moving bed, at different points of the conical zone. The study comprises the influence of both the contactor geometry and the solid type on the pressure drop profiles and the general flumov performance. The angle of the conical device joining the two zones is an important geometrical parameter and, in the range studied, the flumov performance does not depend on the tested solid size and type.     

纤维膜脱硫醇工艺在惠炼液态烃脱硫醇装置中的应用

文章介绍了纤维膜接触器的工作原理及在惠炼液化气脱硫醇装置中的应用情况,结果表明装置运行状态良好,性能稳定,脱硫醇效果好。     

环境化工中的气/液膜接触分离过程及其特性

阐述了新型膜接触器由于避免了传统分离设备的一系列缺点和不足,具有操作范围宽,分离效率高,气液两相的流速可独立控制,可直接线性放大和结构紧凑等众多优点,日益成为分离科学研究的热点。并着眼于3种气/液界面膜接触分离过程(膜吸收、膜蒸馏、膜结构填料替代)在废气、废水等环境治理与化工分离方面的研究,从膜接触器结构、膜材料、传质、分离效率等方面详细分析和探讨了三种膜过程的分离特点,并对其作用原理、操作参数及分离性能进行了综合比较。     

THE RECIPROCATING PLATE COLUMN—DEVELOPMENT AND APPLICATIONS

Reciprocating plate columns (RPCs) were first proposed in 1935 but most of the development has occurred in the past 30 years. Three types of RPC are in use in industry for liquid-liquid extraction, in diameters up to about 1·5  m: The Karr column (U.S.A. and Europe), the VPE column (Eastern Europe) and the vaned-perforation plate (KRIMZ and GIAP) columns developed in the U.S.S.R. All types of RPC operate on common principles, but their design characteristics differ, and basic knowledge must be supplemented by engineering tests with the system of interest. The RPC appears to have promise as a gas-liquid contactor and recent research has suggested possible design modifications for this application.     

反胶团萃取蛋白质设备

综述了反胶团萃取蛋白质设备的研究进展.按设备形式和操作方式的不同将反胶团萃取设备分为膜萃取器、离心萃取器、混合澄清槽和微分萃取器,指出了各自的优缺点,强调了萃取设备的基础研究和开发新型反胶团萃取设备的必要性.