Some aspects of generating unit availability models

A comparison is presented of some of the basic generating unit performance data from the North American Electric Reliability Council-Generating Availability Data System (NERC-GADS) and the Canadian Electrical Association-Equipment Reliability Information System (CEA-ERIS) reporting procedures. The authors also illustrate some of the additional information which can be produced from the continuous state monitoring procedure used by the CEA. This is exemplified by Weibull analysis of state residence time distributions, consideration of the effect of low operating factors for conventional fossil fuel units, and modified models for peaking units     

Significance of interface barrier at electrode of hematite hydroelectric cell for generating ecopower by water splitting

Recent increase in energy demand and associated environmental degradation concern has triggered more research towards alternative green energy sources. Eco‐friendly energy in facile way has been generated from abundantly available iron oxides using only few microliters of water without any external energy source. Hydroelectric cell (HEC) compatible to environment benign, low cost oxygen‐deficient mesoporous hematite nanoparticles has been used for splitting water molecules spontaneously to generate green electricity. Hematite nanoparticles have been synthesized by coprecipitation method. Chemidissociated hydroxyl group presence on hematite surface has been confirmed by infrared spectroscopy (IR) and X‐ray photoelectron spectroscopy (XPS). Surface oxygen vacancies in nanostructured hematite have been identified by transmission electron microscopy (TEM), XPS, and photoluminescence (PL) measurement. Hematite‐based HEC delivers 30 mA current with 0.92 V emf using approximately 500 μL water. Maximum off‐load output power 27.6 mW delivered by 4.84 cm² area hematite‐based HEC is 3.52 times higher than reported 7.84 mW power generated by Li‐magnesium ferrite HEC. Electrochemistry of HEC in different irreversible polarization loss regions has been estimated by applying empirical modeling on V‐I polarization curve revealing the reaction and charge transport mechanism of cell. Tafel slope 22.7 mV has been calculated by modeling of activation polarization overvoltage region of 0.11 V. Low activation polarization indicated easy charge/ion diffusion and faster reaction kinetics of Ag/Zn electrode owing to lesser energy barrier at interface. Dissociated H₃O⁺ ions diffuse through surface via proton hopping, while OH^? ions migrate through interconnected defective crystallite boundaries resulting into high output cell current.     

300 MW机组水力排渣自动控制系统的设计与应用

本文以某电厂2×300 MW机组水力排渣系统为例,根据水力排渣的工艺特点,提出自动控制系统的总体设计方案,包括设备级PLC的组态、管理级IPC的监控、测量仪表的选型和软件程序流程框图的设计等,供工程技术人员一起商榷并探讨。     

Floating type ocean wave power station equipped with hydroelectric unit

The authors have invented the unique ocean wave power station,which is composed of the floating type platform with a pair of the floats lining up at the interval of one wave pitch and the counter-rotating type wave power unit,its runners are submerged in the seawater at the middle position of the platform.Such profiles make the flow velocity at the runner is twice faster than that of the traditional fixed/caisson type OWC,on the ideal flow conditions.Besides,the runners counter-rotate the inner and the outer armatures of the peculiar generator,respectively,and the relative rotational speed is also twice faster than the speed of the single runner/armature.Such characteristics make the runner diameter large,namely the output higher,as requested,because the torque of the power unit never act on the floating type platform.At the preliminary reseach,this paper verifies to get the power using a Wells type single runner installed in the model station.The runner takes the output which is affected by the oscillating amplitude of the platform,the rotational speed and the inertia force of the runner,etc.     

Development of a PC-based data acquisition system for performancemonitoring on an 81 megawatt steam cycle electric power generating unit

A computer-based performance monitoring system has been successfully developed and implemented on an 81 MW steam cycle generating unit. The instrument, data acquisition, computer, and software requirements for the system are discussed. This PC-based system was designed in such a manner that it is transparent to the unit's existing control scheme. Data from this system permits the setting of operating limits to avoid ongoing problems of turbine blade damage     

Analysis of a diesel-engine driven generating unit and thepossibility for voltage flicker

Flicker complaints have been received from customers connected to a diesel engine generator distribution feeder and the voltage causing the flicker has been measured in field tests. These tests confirmed that the voltages vary by up to three percent from normal and this variation begins when the engine-driven generator breaker is closed. The reason for the variation is believed due to the poor quality of fuel used in a diesel engine driven generator connected to the distribution feeder, where the low calorie fuel causes occasional misfiring of the engine. Misfiring of the engine can cause large changes in mechanical torque of the prime mover. This paper shows that such torque changes can cause voltage variations with frequency components that may cause lamp flicker. It should not be implied that engine-driven generators will cause voltage variations of the type noted here, since the variation of voltage also depends on other factors, such as the strength of the interconnection to the electric utility system     

The determinants of cost efficiency of hydroelectric generating plants: A random frontier approach

This paper analyses the technical efficiency in the hydroelectric generating plants of a main Portuguese electricity enterprise EDP (Electricity of Portugal) between 1994 and 2004, investigating the role played by increase in competition and regulation. A random cost frontier method is adopted. A translog frontier model is used and the maximum likelihood estimation technique is employed to estimate the empirical model. We estimate the efficiency scores and decompose the exogenous variables into homogeneous and heterogeneous. It is concluded that production and capacity are heterogeneous, signifying that the hydroelectric generating plants are very distinct and therefore any energy policy should take into account this heterogeneity. It is also concluded that competition, rather than regulation, plays the key role in increasing hydroelectric plant efficiency.     

CKD0型机车自励式辅助发电系统

介绍了辅助发电机自励工作原理和控制电路的设计过程.     

Variable structure and time-varying parameter control forhydroelectric generating unit

A variable-structure control strategy relative to the variable plant structure and output variation is developed, and a nonlinear compensation approach is proposed and analyzed. Moreover, for a certain plant structure with variable parameters a time-varying parameter control approach is developed, and its stability is analyzed and proved. Simulation results show the effectiveness of the proposed control strategy applied to an hydroelectric generating unit     

对内燃机车检修制度及延长修理公里的分析

分析了机车故障分类和柳州机务段修理周期的变化及故障分布情况,对九间隔和六间隔修理周期结构进行了对比,指出六间隔修理周期大大减小了修理工作量,提高了机车可靠性.     

制氧系统的节能降耗途径

制氧系统是钢铁企业的高耗能生产装置,要消耗大量的电能和工业生产水,南京钢铁联合有限公司(简称:南钢)制氧电耗占南钢总电耗量的18%左右.同时制氧生产的氧气、氮气和氩气又是下游用户的能源介质,提高氧氮的利用率、寻求最佳的供应模式是制氧节能降耗的重要课题.文中从降低制氧电耗和控制气体放散率,做好气体的综合利用两方面总结了制氧系统节能降耗的举措.     

关于50MW机组起动时汽封蒸汽来源的探讨

在５０ＭＷ机组电厂的建设中，不设起动锅炉房，利用现有的连续排污扩容器，对系统进行局部修改，在第一台机组建成起动时，利用锅炉连续排污水经扩容后产生的扩容蒸汽向汽封送汽，使汽封及汽封加热器能正常投入使用，提高机组的经济性和安全性。     

基于LabVIEW的风光互补发电户用监测系统

建立小型独立的风光互补发电户用系统,是解决拥有风能和太阳能资源的无电地区供电问题的最佳选择。为能够合理评估和验收风光互补发电户用系统,利用LabVIEW开发了一套实时采集与监测系统,通过数据采集卡、传感器等设备共同完成数据采集、处理、显示和数据库保存,报表生成等功能。     

Solar electric generating system resource requirements

The potential consumption of materials, land, water, manpower, energy, and money by four proposed solar electric generating systems: a terrestrial solar thermal, a terrestrial photovoltaic, an orbiting solar reflector, and a satellite solar power system are analyzed. The evaluation demonstrated that, per megawatt of electrical generating capacity, the terrestrial solar thermal system would require less manpower, less energy of production, and less money than would the extra-terrestrial systems.     

机务段机车检修质量管理信息系统

1引言实行机车检修生产、检修质量管理的微机化管理,建立机车检修质量信息系统,不仅可以减轻各级管理者的工作强度,而且还可以通过微机管理让机车检修生产、检修质量管理更加规范化,提高管理质量,提高机车检修效率和检修效益。这是企业现代化管理的需要,也是机务系统未来利益保     

电网系统发电机组的合理选择

本文从电网系统的可靠性和经济性出发,对几种主要的发电机组的特点进行了分析比较。指出应根据电力负荷的需求情况,合理地选择和搭配发电机组,并且要科学地调度运行,才能取得最好的系统可靠性和经济性。     

湖南镇电站4#机导水机构改造

湖南镇电站机组采用刚性金属密封、三支点结构、不锈钢材料、钢背聚甲醛轴套、旋套式连杆等新材料、新技术改造后 ,效果相当理想     

考虑机组组合问题的机组检修计划优化新模型

以经济费用最小为目标函数,建立了发电机组检修计划优化问题（UMS）新模型。由于生产费用在经济费用中占有的比例最大,因此在计算新模型的生产费用时考虑了发电机组组合优化问题（UC）。鉴于考虑UC问题的UMS问题为双层优化问题,其中UMS问题为上层优化问题,UC问题为下层优化问题,提出了一种改进离散粒子群算法（MDPSO）,并将其用于搜索UMS问题的最优解向量,即解决上层优化问题;而由于拉格朗日松弛法在解决UC问题上具有计算速度快、结果精度高等优点,将其用于解决下层优化问题。利用该新模型和MDPSO算法对IEEE-RTS系统的机组的年检修计划进行优化,并与离散粒子群算法（DPSO）比较,结果表明DPSO算法在解决UMS问题上具有精度高、收敛速度快等优点。     

Energy analysis of a power generating system

The application of energy analysis to nuclear power has provoked considerable controversy about both methodology and conclusions. This paper looks at the results of a UKAEA developed computer programme applied to a variety of nuclear scenarios. It concludes that energy analysis can add to understanding of energy problems but that the results can be misleading if applied to a single resource like fossil fuel. Any meaningful investment in nuclear power is not likely to repay its investment energy for at least four years after the first station is commissioned.