"延保服务"离我们有多远?

有关数据显示:早在2005年底,我国的电视机、电冰箱、洗衣机的社会保有量就分别达到3.5亿台、1.3亿台和1.7亿台;吸油烟机达到8000万台;空调1.17亿台;电脑和手机保有量超过2000万台     

高压加热器的运行故障分析

归纳近年全国各电厂发生的高压加热器故障情况,主要由管束爆管、水位失控、配套件发生故障及操作不当所引发.现电厂对高加的正常运行,其重视程度前所未有.这不仅因为高加投运与否直接与电厂出力和经济效益有关,而且会直接影响整个机组的安全性.因此,提出各种保障措施,确保高压加热器能高效正常地运行.     

传统家电企业图谋小家电市场——访广东志高空调有限公司家电营销公司总经理蔡吉强

在2007年顺德国际家电博览会上,小家电产品的展示占到极大的比重,而且值得注意的是,在众多的小家电产品企业中,不乏志高、长虹、新飞、奥克斯等以空调、彩电著称的传统家电制造商。对此,这些大家电企业都自信地认为,他们能够凭借各自的品牌效应与渠道在未来的3～5年内占领部分市场。业内人士认为,这些传统家电企业的进入能够对小家电行业的发展起到一定的作用,不过这一产业仍需要引导、提高。     

2008华南锂电高层论坛(国际年)

2008年3月4日,第三届华南锂电高层论坛(国际年)在深圳会展中心隆重开幕.本次大会由信息产业部电信研究院、信息产业部数据通信产品质量监督检验中心和中国威尔克实验室主办,由深圳邦凯电子、IDG、深圳六方展览等联合策划承办.本届论坛以"中国锂电--从制造走向创造"为主题,同时强调"新技术、新材料、新应用",针对锂电的生存现状,通过专家的"视角"探讨今后市场的发展趋势.     

希望海信科龙是我退休前最后一个事业——访海信科龙电器股份有限公司副总裁周小天

4月17日上午九点三十分,他首次以海信科龙电器股份有限公司(以下简称海信科龙)副总裁的身份出席了在上海举办的中国家电博览会(以下简称家博会)开幕式;下午,在简单看完家博会后,他又赶赴距上     

空调、洗衣机用电机漆包线"铝代铜"进行时?

"我们正在研究并尝试使用电机漆包线铝代铜方案,现已进入小批量试产."江苏三江电器集团副总经理环剑斌称;"我们已经开发出空调用铝漆包线电机."威灵电机有关负责人表示;"我们也想在洗衣机用电机上尝试铜铝替代."无锡小天鹅华印电器有限公司有关技术人员称.     

标准促进行业发展企业仍需有所担当

产品标准是一个行业发展的基础,而标准背后则是企业强大的核心竞争力和自觉为社会、人民利益严格要求自身的决心和毅力。在国民经济发展的大环境下,与生活生产相关的每一个产业都有无数规则控制着中国产业的发展,电信,网络,钢材,饮料,物流,背后是一长窜名字摩托罗拉,英特尔,可口可乐,沃尔玛,他们就是规则的制定者。规则是什么?规则就是标准,就是不战屈人之兵。同样在中国的家电市场上,面临标     

中国火电建设发展史(2)

"中国火电建设发展史"原系"中华人民共和国电力工业史"的一部分,该书由10多位资深专家分工撰编多年,但迄今未能付梓出版。现将其中"火电建设"部分单独刊出,本刊以连载方式发表,以飨读者。写史要求实事求是,秉笔直抒,总结经验教训,探讨发展规律,以史为鉴,鉴往知来。火力发电在我国电力工业史中始终处于主导地位,在21世纪的电力发展中,火电建设仍将处于主导地位,愿全国火电建设者,不懈努力,为全面建成小康社会和实现四个现代化做出自己的贡献。     

高性价比之选日立P42E101C等离子电视

一直以来,等离子电视与液晶电视的纷争几乎从未停息过,从最初的分辨率高低对比,响应时间和屏幕拖影问题到现在的色彩画质效果、健康护眼等方面的新说法,两大平板主流极尽所能地宣传各自的优势特点。但是,随着今年以来液晶面板产能的增加,大屏幕特别是40英寸以上的高清液晶电视的价格如雪崩般降下了很多,不少品牌的产品纷纷降到了万元以内,对消费者产生了极大吸引力;而相比之下,几乎能够兼容高清信号的等离子都在万元以上,等离子电视在大屏幕领域的优势越发被削弱了。日立P42E101C等离子电视的推出无疑为现在的等离子阵营注入了一针强心剂,它一方面继承了等离子电视优异的画质显示性能,更可贵的是不到9000元人民币的价格,令这款产品成为了众多平板电视中的高性价比之选。     

关于加强湖南电力调度管理工作的思考

在进行地区电力调度系统安全性评价、安全生产检查、班组建设座谈会和问卷调查等调研的基础上,根据电力系统安全优质经济运行的客观要求,指出电力调度应完善统一调度、分级管理的原则,实施"统一制度,统一标准,统一平台,科学考核"的管理模式.     

Strategic prospects of the electric power industry of Russia

The prospects for the development of the electric power industry of Russia adopted at a regular stage of working out the Energy Strategy and the General Plan of Distribution of the Electric Power Facilities are discussed. The monitoring of the progress in the implementation of the Energy Strategies for the periods until 2020 and 2030 adopted in 2003 and 2009 has, in general, validated the correctness of the estimated volumes of the energy resource production under overestimation of the expected domestic demand owing to an excessively optimistic forecast of the real development of the economy. The priority lines of the national energy policy in electric power and allied industries proposed in the Energy Strategy for the period until 2035 are considered. The tools for implementation of most of the proposals and the effectiveness of their implementation have yet to be defined more concretely. The development of the energy sector and the electric power industry under the conservative and optimistic scenarios of the development of the country’s economy has been predicted using the SCANER modeling and information system, viz., the dynamics of the domestic consumption, export, and production of the primary energy and the electric power has been determined and the commissioning and structure of the required generating capacities and the consumption of the basic types of the energy resources by the electric power industry and the centralized heat supply systems has been optimized. Changes in the economic efficiency of the nuclear and thermal power plants under the expected improvements on their cost and performance characteristics and an increase in the domestic fuel prices are presented. The competitiveness of the wind and solar power production under Russian conditions has been evaluated considering the necessity of reservation and partial duplication of their capacities when operated in the power supply systems. When optimizing the electric power industry as a subsystem of the country’s energy sector, the required amounts of capital investments in the industry have been assessed. Based on the obtained data and the predicted prices of fuel in the main pricing zones of Russia, the ranges of changes in the prices of the electric power in agreement with the macroeconomic restrictions on their dynamics have been calculated.     

Detection of volatile impurities in turbine oils by the heat-pulse testing method

The research is aimed at development and implementation of methods and devices to control critical sections of the oil system of the power equipment that operates in the real time mode. The task was to develop a method for rapid detection of volatile impurities in turbine oils. The approach to the study is based on quantitative assessment of the short-term thermal stability of the substance that is formally associated with the content of the volatile impurity. The approach was selected on the basis of the results of search experiments taking into consideration the formulation of requirements for the method and the device, viz., (1) the method should reliably determine the moisture content in the range of 10–150 g of the impurity per ton of oil and (2) the device is to be applicable “in situ.” For this purpose, a variant of the method of the controlled pulse heating of a wire probe, a resistance thermometer, has been developed. The advantages of the method are its speed, sensitivity to small contents of volatile impurities regardless of the nature of the impurity, and smallness of methodologically contributed perturbation. The heating conditions of the probe most sensitive to the appearance of moisture— including its trace amounts—in the system, has been defined. The duration of the measurement is on the order of milliseconds; the heat flux density through the surface of the probe reaches 1 MW/m². The essence of the method consists in measuring, in the characteristic time interval, the temperature of the thermal instability onset associated with the content of the volatile impurity. The approach proposed by the authors is aimed at increasing the lifetime of the oil and preventing unpredictable failures of the operating equipment.     

On computation of the transformation coefficient in the computer simulation of electric-power systems of arbitrary configurations

We consider the possibility of computing the transient processes in an electric-power system of an arbitrary topology according to an algorithm taking into account the transformation coefficients of the transformers contained in the system under investigation. This problem arises when computing the dynamic modes since the structure of an electric-power system may be different at different time points. The key problem of calculating an electric-power system of an arbitrary configuration is the use in the system of elements such as transformers as the voltage levels in a part of the system are not known in advance. The problem can be solved by matching the transformer tree, which affects the voltage level of the branch for every branch of the scheme. This method is similar to the method of matching the trees of the key to every branch. When forming the matrices of the nodal conductances and driving currents, a topological list based on the principle of the element-by-element contribution is used. The main advantages of the method based on the topological list are that it does not require observation of the order of the line numeration and its high algorithmic level, which ensures minimization of the computational effort required for computerized derivation of the equations. To determine the transformation coefficient for a branch, it is necessary to pass into the depth on any of the arms of the transformer tree to the last leaf cell, subquentially multiplying the transformation coefficients of the enumerated transfomers. The complete transformer tree can be used to verify that the transformers are correctly connected to the circuit. From the point of view of trends in the development of information technologies, the approach in question allows not only automation of individual subject phases of the design, but also consideration of simulation of the interaction of electrical equipment in an electric-power system, generation of systems of scheduling, economic planning, determination of risks of equipment failure, etc.     

On the minimum hybrid rank of a graph relative to a partition of its edges and its application to electrical network analysis

We consider the following problem in this paper: given a partition of the set of edges of a graph such that the subgraphs on the blocks of the partition are connected, what is the minimum number of node fission (splitting a node into two) and node fusion (coalescing two nodes) operations that will destroy all circuits containing edges from more than one block of the partition? This problem can be seen to be a generalization of the problem of determining the minimum hybrid rank of a graph. We may therefore regard this minimum number as the minimum hybrid rank of the graph relative to a specified partition of the edge set of the graph. We give an efficient algorithm for the construction of a minimum length sequence of such operations. Our solution can be applied to the problem of analysing networks after first decomposing them into subnetworks-the equations of the network can be displayed in a bordered block diagonal form where the blocks along the diagonal correspond to the subnetworks and the thickness of the border corresponds to the minimum hybrid rank relative to the partition of the sets of edges of the network into the sets of edges of the subnetworks.     

Powerformer一次系统设计及运行实例简介

Powerformer是一种集成了传统发电机和升压变压器功能的新型高压发电机,是在发电技术领域取得的最新进展。它通过利用交联聚乙烯（XLPE）电缆绕制定子绕组,克服了困扰发电机绕组设计的绝缘问题,使得其机端电压在电缆绝缘水平范围内可以任意调节,实现与高压电网的直联。结合目前实际运行的Powerformer的情况,介绍了Powerformer关键部件的设计原理、运行和试验状况、投资及运行经济效益分析、应用前景等。     

On ensuring invariance in problems of control of rail-line conduction

In electrified transportation, the rail network is used as a return conductor of the traction network. The resistance of the components of the rail network to the traction current within the track circuits is stabilized by the rail bonds (RBs), which are classified as “welded,” “plug-in,” and “spring” rail bonds. Depending on the type of traction, copper or steel–copper RBs of various sections are used; therefore, the current conductivity of the rail line depends on the design of the rail network and the operating conditions and maintenance of the track circuits. Analysis of the distribution of failure in the track-circuit elements shows that the faults in the rail bonds are one of the leading causes of failure in the track circuits. For example, during the fourth quarter of 2016, this figure for the Kuibyshev Railroad, which is a branch of OAO Russian Railroads, was 20%, with the track circuits accounting for 57% of the total number of failure events in the devices of the railroad automation and telemechanics systems. The number of failure events has increased in 2 maintenance sections out of 11 compared with the third quarter of 2016 including failure in rail bonds. This article deals with the problems of continuous monitoring and diagnostics of the conduction of the rail lines on the basis of the principles of invariance to the disturbing actions.     

引进型300MW机组易发振动故障的诊断处理方法

本文总结了上海引进型300MW汽轮发电机组轴系的组成、各个轴承的型式以及此种汽机目前在山东省的投运状况。重点介绍了该型机组的易发异常振动的8种故障,如低压转子不平衡、发电机励磁电机三支承转子不平衡、发电机转子热不平衡、低发对轮螺栓松动、低发对轮连接螺栓护板撕裂脱落、发电机励磁电机对轮螺栓紧力不足、励磁机轴晃动大、发电机密封瓦碰磨、副励磁机动静碰磨以及7号可倾轴瓦柱销磨损碎裂等。在分析总结调试及大小修该型机组异常振动的故障过程中,给出了各个故障形成原因、机理、表现、以及各个故障的最佳处理方法。最后提出该型机组低压转子4号轴承异常振动、发电机转子的热态不平衡、发电机励磁电机三支承平衡、励磁机7号轴承振动的处理方法,以及在机组大修及运行中应注意的问题。     

整流罩结构对电机机座表面对流传热特性的影响

为了尽可能地降低全封闭风扇冷却（TEFC）电机各部件的温升,避免过高温升对绝缘结构的破坏,采用数值计算方法研究了整流罩结构对TEFC电机机座表面对流传热特性的影响。首先,对一台样机进行温升试验,绕组温升的仿真值与试验值的误差为6.2%,验证了数值计算方法的可行性。其次,在数值计算时将样机三维模型做必要的简化,着重研究了整流罩外径、整流罩端面与翅片端面的间距以及电机转速对机座表面横向平均努塞尔数的影响。最后,结果表明机座表面翅片结构一定时,存在一个最佳的整流罩外径值使机座表面的对流传热效果最佳;整流罩端面与翅片端面接触时,机座表面的横向平均努塞尔数最大,同时机座表面的对流传热能力随着风扇转速的增大而增大。     

The use of a topological list for calculating the parameters of electric-power systems on the basis of the node-voltage method

The software implementation of the node-voltage equations for calculating the parameters of electric-power systems on the basis of the topological list is considered. Of the well-known modifications of the node-voltage method, it is proposed to use the equations for node voltages in the form of a current balance when specifying a constant-conductivity load. To eliminate the harmonic components during calculations, the equation for each element of the electric-power system is represented in the Park–Gorev axes. When forming the matrices of the nodal conductivities and specifying currents, a topological list that is based on the principle of piecemeal contributions is used. The key advantages of the method that is based on the topological list are that it is unnecessary to observe the order of numbering rows and that this method is highly algorithmic, thus providing the minimization of the computational efforts in compiling equations on a computer. The essence of the piecemeal-contribution principle lies in the successive formation of matrix coefficients, as row-by-row processing of the topological list is performed. An algorithm for the formation of equations according to the node-voltage method using the topological list in the form of a block diagram is presented. Calculation using the node-voltage method on the basis of the topological list is an independent task, as well as representing a component of more complex types of calculations, such as optimization of the normal modes, stability analysis, reliability assessment, etc. The interrelations between individual components of the process of solving the problem of calculating stationary and quasi-stationary operating modes of the electric-power system with respect to input and output information are shown. The formation of the equations of the structural elements in stationary and quasi-stationary modes of the electric-power system of a factory is based on the linearization of the initial node-voltage equations.     

新型主机防火墙模型的研究

针对局域网内主机用户的安全问题 ,对边界防火墙的不足之处进行了分析与研究 ,对主机防火墙采用的技术及存在的问题进行了探讨与研究 ,并给出了一种新型主机防火墙的设计方案 ,包括实现平台的选择、包过滤模块、IP层安全机制、入侵检测等模块 ,提高了局域网内部的网络安全性。