煤气加热炉风机两路电源自动切换

1　概述煤气加热炉工艺要求,风机电机若断电,风压则降低,煤气切断阀将自动切断煤气总阀,这将导致加热炉熄火。为了解决风机供电电源跳闸引起加热炉熄火的问题,需要为风机提供两路电源,而且必须是来自两个变电所的电源。具体方案如下:引接两路电源,一路为主电源,作为正常生产使用,另一路由于变压器或线路的原因只能作为辅助电源,作备用,仅在主电源跳闸时投入使用,维持风机运行,不作为正常生产中使用。2　工作原理其原理如图1。正常供电时,先合ZK1,后合ZK2,1XC、1SJ得电吸合,因互锁2XC不会得电,风机起动系统由主电源供给,即L1、L2、L3(…     

整流机组控制电源失电保护

在整流机组的保护设置中,常规设计往往未包含控制电源失电保护,此种保护一般由使用厂家订货时要求整流柜生产厂家设置,若使用厂家没有明确要求整流柜生产厂家设置,则可能出现缺少控制电源失电保护的情况,使整流装置运行存在安全隐患,针对当前对控制电源失电保护重视不够,缺乏标准设计的状况,有必要对控制电源失电保护做一个详细的说明。1、设置控制电源失电保护的意义(1)PLC故障或失电时及时跳闸由于整流机组辅机如:油风冷却器油泵、风机,水风冷却器水泵、风机等均由PLC控制,并且通过PLC的一个输出节点启动中间继电器,再由此中间继电器…     

高炉风机低电压保护的完善

介绍低电压保护的发展及常规低电压保护的缺陷，提出了带无流监视的低电压保护思路。对杭钢高炉风机实施带无流监视低电压保护后，保护的正确性和可靠性达到100％。     

除尘风机停机连锁及升降速装置的改进

针对湘钢二炼钢厂一次除尘风机的现状，自行设计了风机断耦及延时保护程序。通过对风机实行PID分段控制，满足了生产要求，同时取得了较好的经济效益。     

6kV高压柜越级保护故障分析与整改

介绍了金隆铜业有限公司稀贵金属车间6kV备用供电电源系统,结合生产实际应用过程中所发生的6kV备用电源微机综合保护装置越级保护跳闸的故障现象,对故障的检查处理经过进行了分析,重点研究了整改前6kV备用供电电源发生越级保护跳闸的原因,并介绍了相应的整改方法与处理措施。     

同步电机的稳定界限和低电压保护装置

我国的电动机低电压保护一直采用定时限特性。在电力系统电压严重降低或电源短时小断时，往往引起低电压保护动作而甩负荷。本文分析表明，同步电动机的稳定界限是反时限特性。因此，作为失步保护后备的低电压保护也应具有反时限特性。     

发电机零序保护误动原因分析

根据中铝山西分公司自备电厂二号发电机一次接线特点和保护配置情况,对造成二号机跳闸原因进行了系统分析判断,指出了消弧线圈电缆在零序互感器接地点前发生断线是造成二号机零序保护误动的唯一原因。     

110 kV变电站Ⅱ站电容器跳闸故障分析及解决

介绍了邢钢110kV变电站Ⅱ站外表无任何异常现象、保护熔断器完好的电容器组因不平衡电压保护跳闸,设备无法投入运行的情况,分析认为发生该故障的原因是二次线圈三相电压不平衡。     

电网暂态波动引发晶闸管整流系统甩负荷的分析与处理

针对实际运行中晶闸管整流控制装置故障引发整流机组跳闸的原因，开展了分析论证，通过开展晶闸管整流控制装置电源扰动试验，最终找到了晶闸管整流控制装置故障的具体原因，采取相应措施，使系列电流波动≤±50 A，整流效率由之前的98.1%提高至98.4%，有效降低了整流损耗。     

350MW发电机组高压转机低压减载保护方式的设计优化

350 MW发电机机组低压减载功能使用6 kV高压转机综合保护装置的附带功能,未使用6 kV母线电压互感器屏专用综合保护装置低压减载功能,两种方式都能满足低压减载功能,但使用前者在处理电压互感器断线事件时存在一定风险,处理不当有引发低电压减载动作的可能,使高压转机跳闸,进而引发机组跳闸事故。功能优化后的低电压减载功能系统简单集中,处理电压互感器断线缺陷简单、省时,有效避免低电压减载保护误动,引发机组跳闸非计划停机。     

熔炼次数对M17返回料合金成分、组织和性能的影响

实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。     

Shijiazhuang will Build the World's Biggest Replacingcopper-with-aluminum Cable Production Base

正Shijiazhuang City will build the world’s biggest replacing-copper-with-aluminum cable production base,the annual output value can reach 100 billion yuan,in the future it will develop replacing-copper-with-aluminum highend industry cluster.This piece of news was learned by the reporter at the Rare Earth highiron Aluminum Alloy[Nonferrous Business Opportunity:Aluminum alloy door]Cable Conductor New Technology Application Seminar held at the provincial capital.     

Chongqing is Preparing to Set Up Nonferrous Metal Exchange,in a Bid to Become the Transit Place of Kazakhstan Copper

正Since the beginning of Chongqing’s upgrading to a municipality directly under the Central Government,Chongqing City has established direct friendly relationship with Almaty,Kazakhstan,and carried out a series of cooperation in commerce and trade,and culture     

Guangxi Baise Extends Industrial Chain to Combat Loss in Aluminum Business

正"For each tonne of aluminum being produced,the upstream enterprise on the aluminum industrial chain will suffer loss about 2000yuan."Said Liang Xiao,Deputy Director of Pingguo Industrial Park Management Committee under the Guangxi Baise City,one of the four major aluminum industry bases in China,on August 11.Extending aluminum     

JOURNAL OF IRON AND STEEL RESEARCH INTERNATIONAL ANNUAL CONTENTS Volume 21(2014)

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Chinalco Straightened Out Copper Assets,and Delegated Stock Equity of Yunnan Copper

正Immediately after the news that Chinalco transferred 58%stock equity of Yunnan Copper Group to its wholly-owned subsidiary China Copper Corporation Limited free of charge was disclosed on July 9,many individual investors couldn’t help but to think:Does it mean China Copper Corporation Limited will assemble assets for overall listing?At present,among main copper business companies under China Copper Corporation     

The Development and Reform Commission Encourages Private Capital to Enter Geological Prospecting Field

正At the press conference recently held by the National Development and Reform Commission under the theme"Deepen Reform in Investment AuditApproval System",when answering questions from reporters,Huang Min,Director of the Department of Fixed Assets Investment of the National Development and Reform Commission,said that in the future it would continue to intensify efforts in geological prospecting,and actively guide social capital to enter this field.     

Guangxi's first Nickel Industry Development Research Report Was Released

正Recently,Guangxi Metallurgical Research Institute,a subsidiary of Guangxi Nonferrous Metals Group,completed survey on laterite and related manufacturers in the region,by combining the current development status of laterite both at home and abroad,it compiled Guangxi’s first"Research Report on the Development of Guangxi Nickel Industrial Chain"which adopted laterite as the study subject.This report expounded on the current     

China’s Major Non-ferrous Metals Imports & Exports(End of September. 2014)

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China's Major Non-ferrous Metals Imports & Exports

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