变频器壳体的防爆设计

变频器应用范围很广,在煤矿等易燃易爆场合应用,对变频器的防爆需要特别设计。通过研究爆炸的原理,并结合相关力学原理,对变频器壳体进行防爆设计,然后建立三维模型,进行受力分析,并对壳体结构进行优化处理,对变频器具有一定的防爆作用。     

中低压防爆变频器功率单元热分析

防爆变频器功率开关器件的热量计算和散热能力设计是防爆变频器可靠性设计的重要环节。提出了一种外部热管散热加强制风冷的散热方式,通过Flow Simulation模块进行热仿真分析,得到中低压防爆变频器的温度变化规律,验证了该设计方案的可靠性。研究和试验表明,利用外部热管散热加强制风冷散热的防爆变频器能够在矿井下稳定运行。     

MW级矿用防爆变频器EMI滤波器的设计

以MW级矿用防爆变频器为对象,为解决共模干扰对电机使用寿命的影响,设计了EMI滤波器。在分析EMI滤波器的基本原理和防爆变频器的EMI传导通道基础上,实现了基于矿用防爆变频器EMI滤波器的设计,从而减少了共模干扰对电机的影响。通过EMI滤波器波形测试,验证所设计EMI滤波器的可行性。     

DXP40防爆蓄电池单轨吊车中机载变频调速器应用的研究

文章重点介绍了DXP40防爆蓄电池单轨吊车中机载变频调速器应用的设计研究,其中包括变频器的容量计算、变频器散热量和散热器面积的计算。     

三电平组合式防爆高压变频器在煤矿刮板输送机上远距离驱动的应用

介绍了三电平组合式防爆高压变频器在神华新疆宽沟煤矿的实际应用,从分析当前几种常用的防爆高压变频器的传输距离入手,对该款变频器的技术性能、现场应用情况以及所产生的经济效益和社会效益等方面做了论述。     

矿用防爆变频器监控系统的设计

为适应煤矿井下安全生产,介绍了基于PLC及触摸屏的矿用防爆变频器监控系统的设计,PLC负责系统的逻辑控制,触摸屏实现与设备使用者的信息交互,并采用外部按钮控制触摸屏,解决了矿用变频器触摸屏无法通过触碰操作的问题。该系统经实际应用,可实现对矿用变频器的实时监控等功能,运行情况良好。     

变频器在煤矿井下的应用

介绍防爆变频器在煤矿井下应用及如何选型的体会。     

矿用防爆变频器模块化插接式功率单元的研制

针对目前防爆变频器功率单元结构分散、布线杂乱、互换性低和维护麻烦等缺陷,提出矿用防爆变频器模块化插接式功率单元。这种功率单元采用模块化插接式设计,使得结构更加紧凑,布线整洁美观,并且通过插接式结构实现整体推拉,井下单人即可进行维修、更换电气元件。     

交流变频器在煤矿井下应用的现状及其前景

针对我国煤矿电源浪费严重的现状，采用交流变频器既可减小启动电流又可增大启动转矩，介绍国外电机传动及变频器发展情况并在此基础上提出防爆变频器在井下应用情况及前景。     

低压DC/AC变频器在煤矿防爆蓄电池重型车中的应用

为提高煤矿防爆蓄电池重型车系列整车性能,防爆低压DC/AC变频技术在控制器、驱动电路及程序控制上采用全新的设计理念。分析了防爆35t铲板式支架搬运车运行时的变频器工作状态,有效提高了变频器散热功能及整车载重能力,"挖掘特性"的牵引系统提高了车辆低速大扭矩软特性,实现转速和转矩的反比例变化,提高整车牵引力,同时电机输出端电流与额定电流基本相同,工作效率最高达到98%。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

唐口煤矿深部复杂开采工作面瓦斯分源涌出规律研究

研究工作面瓦斯涌出规律对工作面瓦斯治理有重要意义。为了得到唐口煤矿深部3号煤层复杂开采条件下工作面回采时期瓦斯涌出时空演化规律,选取6304工作面作为对象,采用实测方法研究6304工作面瓦斯涌出规律。结果表明:6304工作面瓦斯涌出量为6.534 m³/min,其中煤壁占34.27%,落煤占29.62%,采空区占36.11%;沿工作面倾向由低到高,瓦斯浓度整体为上升趋势,其中1—76号架工作面瓦斯浓度小于0.20%,76—102号架瓦斯浓度上升明显,最大为0.387%;上隅角的后部采空区是工作面的瓦斯主要涌出源,上隅角1号测点瓦斯浓度0.78%,上隅角周边3号、5号、7号、8号、9号测点瓦斯浓度平均为0.643%;周期来压时,上隅角瓦斯相对平时较高。研究为针对性的瓦斯分源监控与灾害防治提供基础。