锅炉受热面腐蚀的起因与预防措施

分析了锅炉受热面腐蚀的机理．提出了预防改进措施．使锅炉受热面免遭腐蚀破坏。     

煤燃烧特性参数与锅炉结构参数的相关性研究

分析了３０余台大型电站燃煤锅炉的煤燃烧特性及其结构特性．提出了煤质特性参数和锅炉结构参数,用以确定大型电站锅炉的主要炉膛结构尺寸．     

强化循环流化床锅炉出口端头效应的试验研究

通过在循环流化床模型上进行的试验研究,提出了强化循环流化床锅炉出口端头效应的方法．试验结果表明,收缩出口结构可以强化循环流化床锅炉出口端头效应,并且收缩出口结构的收缩度对循环流化床锅炉流动特性的影响呈现峰值特征,一般最佳收缩度与循环流化床锅炉当量直径之比为０．５．     

提高670t/h锅炉热效率的实践

通过锅炉冷态试验及效率试验,从理论及实际中分析670t／11锅炉效率偏低的原因,并根据原因分析,利用试验及计算机模拟等方法,找出解决办法,解决了沙角A电厂该类型锅炉长期以来存在的锅炉热效率偏低的问题,使锅炉热效率达到91．3％～92．2％,超过设计值的1％～2％。同时还解决了该锅炉过热器超温和烟温偏差过大的问题。     

挥发窑的余热利用

概述了锌挥发窑余热的特点及其利用方式的确定以及余热锅炉参数的选择，介绍了锌挥发窑余热锅炉结构设计要点并着重阐述了余热锅炉积灰，腐蚀的防止问题．     

基于密相区热平衡的CFB锅炉物料循环倍率测试方法

固体物料的循环倍率是ＣＦＢ锅炉设计和运行中非常重要的技术参数．以密相区为控制体．通过对控制作物料平 衡及能量平衡的分析,建立了热平衡式;根据ＣＦＢ锅炉的特点合理简化之后得出循环倍率的表达式,由该表达式经过常规 的锅炉测试就可测定ＣＦＢ锅炉循环倍率．     

低压锅炉炉水碱度超标的原因及防止措施

目前，低压锅炉普遍存在炉水破度偏高，为此，我们以湖南湘江宾馆、湖南制药厂的低压锅炉为基础兼顾湖南省及省外部分地区的低压锅炉，对原水水质、炉水水质、锅炉排污率进行了调查，分析，指出了造成炉水碱度偏高的主要原因．并就可降低碱度和排污率的４种给水处理工艺进行了讨论．     

超临界直流锅炉起动系统配置方式的选择

由于直流锅炉自身的特点,必须配置特有的起动系统来保证锅炉起停和低负荷运行期间水冷壁的安全和正常供汽。为此,介绍了超临界直流锅炉内置式分离器起动系统的方式．并结合工质及能量回收和锅炉安全运行状况,对内置式分离器起动系统方式：带疏水循环泵式及不带疏水循环泵式的优缺点进行了比较分析．可以帮助技术人员合理选择超临界直流锅炉起动系统的配置。     

浅谈卧式内燃锅壳式热水锅炉的设计

以哈依城市煤气为燃料而设计的WNS2．8－0．7／95／70－Q锅炉为例，着重叙述了卧式内燃锅炉的设计参数，并对卧式内燃锅炉设计中应注意的问题，如螺纹烟管的综合性能的评价和优化分析，烟室前管板的裂纹和泄漏原因及防裂纹、防泄漏措施，卧式内燃锅炉的易爆性及防爆门的设计和排污结构的设计做了深入细致的探讨．     

煤粉炉改循环流化床燃烧的工程实践

针对35t／h煤粉炉技改实践，对传统煤粉锅炉改流化床锅炉进行了分析研究，介绍了利用CFB技术进行锅炉改造的主要问题及具体解决措施，并对锅炉改造在经济效益上进行了分析．     

Ultrasonic motors: Their models, drives, controls and applications

In the last decades piezoelectrically driven ultrasonic motors have become alternative actuators to the conventional electromagnetic motors especially for precise and accurate servo positioning applications. Different types of ultrasonic motors have been constructed and manufactured. Several drive systems have been designed, implemented and proposed for these motors. A variety of control techniques have been applied to them. The research given in this study covers bases of the ultrasonic motors. Theoretical background, modeling, drive systems, control techniques and applications of the ultrasonic motors have been introduced. Firstly, the general overview has been given. Then, modeling studies focused on performance estimation and analysis of ultrasonic motors have been examined. Afterwards, drive systems and control techniques of ultrasonic motors have been investigated. Furthermore, an example drive and control system has been presented. This drive system has been designed as to be controlled digitally. In addition, the important industrial and research applications of these motors have been included. The presented study has been arranged as a review of ultrasonic motors. The important points of specifications, models, drive systems and control methods of the ultrasonic motors have been emphasized.     

电力设备的寿命评估

综述了电力设备寿命评估的各种方法、理论,介绍了国内外对电力设备寿命评估技术的研究动态,同时还对变压器、发电机和电动机的寿命评估方案进行了阐述。     

Novel modeling for the prediction of aged transformer oil characteristics

The effect of aging on transformer oil physical, chemical and electrical properties has been studied using the international testing methods for the evaluation of transformer oil quality. The study has been carried out on twelve transformers in the field and for monitoring periods up to 8 years. The properties which are strongly time dependent have been specified and those which have a great impact on the transformer oil breakdown voltage have been defined. Mathematical models for the breakdown voltage, total acidity and water content as a function of service periods have been given. The validity and applicability of these models for future prediction of these properties have been verified by the good agreement between the measured end predicted values. A multiple linear regression model for each transformer oil breakdown voltage as a function of its water content, total acidity and service period has been introduced and its adequacy has been illustrated by statistical analysis. Another multiple linear regression model has been developed by combining the results of a group of transformers into that of a single equivalent transformer. This model has been validated by predicting the properties of some other transformers and comparing them with the measured values. The comparison showed a good agreement for the results of transformers which have either been used or not in the derivation of the model.     

Capacitive voltage sensor for measuring very fast transient overvoltages in GIS

A reliable technique is needed for accurate measurement of very fast transient overvoltages such as disconnector-induced surges occurring in GIS which have very steep front and high-frequency oscillation. Recently, capacitive voltage sensors with very short response times have been proposed for this purpose. However, few studies have been made on the dielectric properties of materials used for a low-voltage-side capacitor, as well as the frequency bandwidth of the measuring system. In this paper a thin mica plate is proposed for a low-voltage-side capacitor which has a surface coated with silver on both sides. This material has been shown to have stable and high static capacitance up to a high-frequency range. A quantitative estimate also is given for the frequency bandwidth of the measuring system. Furthermore, a practical-scale sensor of this type has been developed which can successfully measure simulated disconnector-induced surges of several hundred kilovolts under similar conditions in GIS.     

On the noise performances of fractal-fractional electrical circuits

In this work, the noise performances of the fractal-fractional electrical circuits have been addressed. The nonlocal fractal calculus has been adopted as our mathematical basis. The fractal time component has also been included for the physical measurability of electrical quantities. The derivations of crucial stochastic parameters of circuit responses, which determine their noise performances, have been performed. Numerical simulations have also been conducted where the influences of Hausdorff dimension of the fractal set, orders of fractal-fractional reactive components, and other parameters on the noise performances have been studied. Regardless to any specific circuit, we have found that the noise performances can be improved by increasing the orders of fractal-fractional reactive components. The optimum Hausdorff dimensions, which the best noise performances can be achieved given the orders of fractal-fractional reactive components, have also been calculated. The results proposed in this work serve as the foundation for understanding noise in fractal-fractional electrical circuits and can be extensively applied to large-scaled circuits, for example, the infinite circuit networks and so forth.     

液压胀接在高加管子管板上的应用

文章介绍了高压加热器几种管子管板胀接结构,对不同胀接手段进行了比较,分析其优缺点;对液压胀接的原理和计算公式以及管子管板液压胀接试验过程进行了表述.介绍了液压胀管应注意的事项和运用在高压加热器上的一些情况,为今后此类产品的生产制造提供了借鉴.     

静电放电火花能量耦合特性研究

研究了典型静电放电火花的点燃能力和火花能量的耦合特性。研究认为点燃一般可燃气体和一般可燃粉尘云的静电放电的临界火花直径分别约为 0 .1、0 .5mm ;电晕放电的点燃能力很弱而传播型刷形放电的点燃能力很强 ;料仓堆表面放电的有效点火能量可考虑为 10mJ ;典型静电放电火花的放电时间基本上不影响火花的点燃效果 ;不同类型的静电放电火花点燃可燃物过程的能量耦合效率不同 ,可高达 10 0 % ,也可能 <1%。     

大型发电机绕组电气故障分析

综述分析了大型发电机绕组所涉及的各类电气故障与不正常运行工况及其危害和一些相应分析解决方法.在发电机内部分别从转子和定子两个方面分析发生在绕组之间和绕组对地之间的故障工况,在发电机外部则分析了机端突然短路和不对称运行给绕组带来的影响.     

Mathematical simulation and parameter determination of regulation of a linear electrical reciprocating machine

A linear switched-reluctance electrical machine (LEM) intended to be used as an electric-power generator together with a free-piston internal-combustion engine (ICE) has been analyzed. Taking into account the hard service conditions of an electrical machine (EM) in close proximity to a cylinder ICE, hottemperature zones and heavy mechanical loads of the EM of the vent-inductor type have been recommended to be used. Development of a control system for this type of machine is one of the most complicated problems when developing it. It has been suggested to determine the reasonable principles and regulating algorithms of the machine that is being considered, as well as its regulation system and energy-data evaluation, on the basis of a model of the electromagnetic process. Taking into account the characteristic properties of the linear switched-reluctance machine as a modeling object, a mathematical model has been developed to solve the problems mentioned above. As stator phases have separate coil-flux guides and are not connected magnetically, the electromagnetic processes in each phase are analyzed independently. For experimental corroboration of ideas for design calculation, an experimental model of the machine has been constructed. Parameters required for modeling the characteristics’ correspondences of flux linkage and phase current’s generating force at various positions of a moving element have been determined for this machine experimentally. Performance of the linear switched reluctance electrical reciprocating machine has been analyzed with the mathematical model with moving-element movement frequencies unfeasible for study on a proving stand. Reasonable parameters of the current pulses’ phases of the machine have been determined, and its energy data have been evaluated. The obtained results have confirmed the correctness of the design approaches, choice of regulation principles, and adjustment of a linear vent-inductor electrical machine of forward and backward action and the feasibility of using it as an electric-power generator together with a free-piston ICE.     

Processing Effects on the Microstructure and Dielectric Properties of Barium Strontium Titanate (BST) Ceramics

Barium Strontium Titanate (BST) ferroelectric thick films have been investigated as potential candidates for use in frequency agile microwave circuit devices. Powder processing techniques such as screen-printing have been used to make BST thick films. However, due to the interactions between the BST and substrates such as alumina, the sintering temperatures for the BST thick films are limited and the resultant films are difficult to achieve full densification. In this paper, the effects of different powder processing conditions (calcination, sintering temperature and time) on the sintering behaviour and dielectric properties of the BST ceramics have been investigated. The dielectric behaviour of the ceramics has been correlated with composition and microstructural features such as chemical homogeneity, grain size and domain wall movements.