Squirrel Cage Induction Motors?Performance Versus Efficiency

The importance of operating motors at peak efficiency for maximum energy savings is discussed. Comparisons of standard motors and high-efficiency motors are shown. Optimum motor design requires a compromise between the various parameters. The effect of starting torque and locked rotor amperes on efficiency and power factor is demonstrated. Proper motor application can result in significant energy cost savings over the life of the motor. These savings can be greater than the initial cost of the motor.     

Increased Cement Grinding Efficiency by Using High-Efficiency Separators

High-efficiency classifiers improve the grain size distribution of the finished cement and reduce grinding power requirements. Theoretical calculations indicate potential power savings of up to one-third at the main mill motor when applying high-efficiency classifiers instead of conventional separators at a cement fineness of 15 percent residue at 0.030 mm. The most commonly used separators of conventional and high-efficiency design are presented and briefly characterized. Data on actual performance of grinding systems are stated which indicate that some 15 percent of the grinding system's power consumption can be saved when applying high-efficiency classifiers instead of conventional separators at 3500-4000 cm2/g (Blaine) cement fineness.     

用分布式温度测量技术提高系统可靠性

本文主要介绍为提高系统可靠性所采用的分布式测凝技术及其温度集成传感器，并指出不同的应用特点。     

Improving Power System Reliability Calculation Efficiency With EPSO Variants

This paper presents an application of evolutionary particle swarm optimization (EPSO)-based methods to evaluate power system reliability. Population-based (PB) methods appear as competitors to the traditional Monte Carlo simulation (MCS), because they are computationally efficient in estimating a variety of reliability indices. The work reported in this paper demonstrates that EPSO variants can focus the search in the region of the state space where contributions to the formation of a reliability index may be found, instead of conducting a blind sampling of the space. The results obtained with EPSO are compared to MCS and with other PB methods.     

供电企业可靠性管理控制效率分析

可靠性管控效率分析不仅有助于发掘供电企业可靠性管控的薄弱环节,因地制宜指导电网规划、生产与维护,还对持续提高供电可靠性水平、提高经济和社会效益等具有重要意义。在分析供电可靠性指标与其管理控制指标关系的基础上,提出了供电企业可靠性管理控制效率分析的两阶段方法,量化供电企业可靠性管控效率、分析影响因素及其影响程度。以广东电网所辖19个地级供电企业为分析对象,验证了所提方法的有效性。     

超超临界机组新技术的可靠性与高效率

本文对２台日本超超临界７００ＭＷ机组的实际运行情况进行了介绍，具有一定的参考价值．     

面向经济性与可靠性的FTU优化配置研究

馈线开关监控终端是重要的配电自动化终端设备,数量众多、安装分散,对数量和位置进行优化配置有利于提高配电自动化系统的可靠性、经济性。对此,提出了一种数量规划与位置优化分步进行的FTU配置方法:首先从经济性、可靠性两方面出发,基于非线性整数规划的方法进行FTU的数量优化配置,并借助遗传算法进行求解;其次考虑馈线开关附近的不同负荷类型及数量,兼顾不同类型FTU的功能特性,进行FTU的位置优化配置,从而达成配电自动化系统中FTU配置的最优方案。实际算例验证了方法的可行性。     

传热对空气标准Diesel循环功和效率特性的影响

用有限时间热力学方法分析空气标准Diesel循环的性能．导出考虑传热效应下循环的功及效率与压比的关系，并得出功与效率的关系和最大功输出时的效率．给出了较为详尽的数值计算结果，它们对实际Diesel机性能的评估及改进有一定的指导意义．     

Increased Chlorine Production and Power Efficiency by Incremental Changes? A Case History

FMC of Canada Limited built a chlor-alkali plant at Squamish, BC, Canada in 1966. The plant design featured the use of DeNora mercury cells and an outdoor cell room. The plant management has implemented a number of changes over the years which increased production capacity by 25 percent, substantially reduced the emission of pollutants, improved power and energy efficiency, and increased the availability of the plant. Further improvements to plant operation are foreseen.     

基于发电系统可靠性分析的能效电厂有效容量确定

考虑到能效电厂的运行具有随机性,能效电厂出力不能简单地用常规设备与节能设备的容量差来计算,而应通过监测能效电厂的运行情况得到能效电厂的出力曲线.文中采用解析法来计算发电系统可靠性,将监测到的能效电厂的出力曲线从负荷曲线中分离,将分离后的净负荷曲线与常规电厂的停运概率表相结合计算发电系统的可靠性指标,同时,利用电力不足期...     

Ways for Improving Efficiency and Reliability of Steam Turbines at Nuclear Power Stations

The current state and ways for improving the effectiveness of steam turbine units at nuclear power stations (NPS) are examined. The specifics of NPS turbines is described. The comparison of NPS steam turbine performance with the performance of steam turbines at thermal power stations (TPS) demonstrates that power units of NPSs are much poorer in effectiveness due to relatively low steam conditions at the inlet and the presence of wet steam already in the first stages of turbines. A decrease in the relative internal efficiency of NPS turbines results from the enhanced negative effect of wetness in the expansion process: in modern NPS turbines, more than two-thirds of the heat drop is spent in the two-phase region, while less than one fourth in TPS turbines. It is demonstrated that the effectiveness of NPS steam turbine units can be increased drastically in the future only through a considerable rise in the turbine inlet steam conditions. This can be achieved by using a heat carrier at supercritical conditions in the NPS reactor. The dependence of the effectiveness of NPS modern turbines on the turbine inlet steam conditions in the applicable pressure ranges of the saturated steam and vacuum in the condenser, as well as on the turbine exhaust area, is examined. For a 1000 MW turbine, increasing the inlet pressure from 6.0 to 8.0 MPa raises the turbine power and efficiency by 3.5%. At a condensing turbine outlet pressure ranging from 2.5 to 7.5 kPa and a constant velocity downstream of the last stage, the turbine power and efficiency can be increased by 7%. The importance of the exhaust area for the turbine effectiveness is revealed. Alternative designs of the flowpath in a low-pressure cylinder are analyzed. A unique configuration of a steam turbine unit with two-stage moisture separation is proposed. The comparison of high-speed turbines with low-speed ones was performed. It is demonstrated that the efficiency of the examined turbines is nearly the same within the accuracy of design calculations and the test results, and it is slightly higher for low-speed turbines due to lower losses with outlet velocity.     

考虑负荷不确定性与运行可靠性的综合能源系统资产利用效率分析

针对当前多种能源耦合程度不断加深背景下,综合能源系统资产利用效率评估方法的研究亟待开展,且对于综合能源系统运行状态的分析未考虑故障运行状态等问题,本文提出了考虑负荷不确定性与运行可靠性的综合能源系统资产利用效率分析方法。首先,构建了表征系统终端负荷不确定性的模型;其次,分别以系统资产利用效率以及系统运行可靠性作为评估系统正常运行以及故障运行状态的指标,对其评估方法进行研究,并采用隶属度函数将不同量纲的指标进行结合;最后,通过实际算例仿真,具体分析了综合能源系统全年及典型日的运行状态,并分析了负荷不确定性对系统资产利用效率及运行可靠性产生的影响,从而验证本文所提理论方法的有效性与适用性。     

提高电站湿法脱硫系统效率及可靠性的几点措施

随着国家新的环保标准《火力发电厂大气污染物排放标准》（GB13223-2011）的颁布和实施,对电站脱硫系统的脱硫性能及装置可靠性的要求也进一步提高。为此,针对影响脱硫系统效率和可靠性的几个关键问题,如事故喷淋冷却、烟囱凝结水处置、脱硫塔系统优化和结构设计、烟道与烟囱的一体化连接以及公用系统配置等,进行了较为详细的分析,并在总结以往设计经验的基础上提出了一系列改进措施,力求在保证高脱硫效率的同时,使系统具有较高的可靠性。     

计及可靠性和经济性的中压配电线路最佳运行效率计算方法

当前中压配电线路运行效率评价过程中采用“N-1”准则难以合理度量在不同负荷结构下线路最佳负载能力,未能充分考虑在不同负荷结构下线路运行经济性的问题,针对以上问题提出了计及可靠性和经济性的中压配电线路最佳运行效率计算方法。首先,结合安全性和经济性两个方面,对中压配电线路的运行效率进行了定义并提出了其计算方法;其次,基于可靠性指标与线路负载率关系解析,提出了不同负荷结构的中压配电线路可靠性评估流程;然后,以经济性最优为目标构建了中压配电线路最佳负载能力优化模型。最后通过算例分析,验证了本文所提方法的有效性和实用性。     

600MW机组引风机改造后可靠性及经济性分析

为降低大气污染物的排放,火力发电厂要进行烟气脱硝、除灰改造,这将引起锅炉尾部烟道系统阻力增加,原有引风机出力将无法满足要求。以乌沙山发电厂3号机组为例介绍了引风机改造方案,对改造后引风机的可靠性和经济性进行了分析。     

Reliability

Every engineer uses the term "reliability," but specific usages too often betray a concept based on folklore rather than upon available techniques for accurate determination. Burdened as the curriculum is today, exact definition and some applications of reliability must be included.     

Demonstrating Reliability

This article highlights some of the recent reliability demonstrations for both ohmic and capacitive MEMS switches and provides a snapshot of the present state of RF MEMS switch reliability for upcoming military and commercial applications.     

Reliability Education

The lack of sufficient formal education in the field of reliability is an accepted fact by both the engineering educator and reliability manager. This paper describes this problem in some detail and contrasts the state of reliability education with other more established disciplines. Some of the previous ambitious attempts to remedy this situation are discussed and some more limited and perhaps more feasible suggestions are presented.     

电力市场下可靠性电价与可靠性市场的研究

着重研究了系统的备用容量与发电可靠性和用电可靠性之间的关系以及不同发电可靠性条件下的发电可靠性电价和不同用电可靠性条件下的用电可靠性电价的确定。提出了满足个性化可靠性需求的交易模式,即由电网公司根据负荷的预计分布规律与备用市场价格确定在不同备用与供电可靠性条件下的备用电源计划安排,从而得到备用电源的费用及单位负荷功率的可靠性电价;电力用户根据自身的用电负荷特征及电网公司公布的可靠性电价申报供电可靠性要求;电网公司根据发电厂机组的可靠性水平确定系统需要增加的备用容量,进而确定发电厂的可靠性电价。