基于NICSYS2000平台的试验数据采集和试验仪表系统与核电厂DCS一体化改进研究与应用

介绍了HPR1000项目核电站试验数据采集(IDA)和试验仪表系统(ITI)以及事件顺序记录(SOE)/事件追踪(TRA)的设置方案,通过对SOE/TRA/ITI/IDA的一体化系统的分析,提出与DCS平台一体化集成的改进措施,实现了真正的仪控平台一体化。该改进处理方案通过在现有的HPR1000项目上的实施与应用,成功减少了机柜/服务器/供电柜等各种资源的占用,同时保证了信号的实时性和有效性。     

风机主控系统SOE功能设计与实现

文章设计了风机主控系统SOE功能实现方案,使用了横河FCN控制器的SOE软件功能,开发了SOE数据文件故障字解析软件,实现了风机主控系统毫秒级SOE功能。通过测试对SOE功能进行验证,测试结果满足风机故障分析要求,达到了预期效果。     

基于DCOM分布式网络的电站综合自动化系统设计与应用

为实现农村小水电站综合自动化的后台监控功能,基于DCOM分布式网络编程技术,系统设计采用分级分层的分布式构架,由集控调度中心控制级通过现场控制级信息数据交互监控现场单元级,实现了集控调度中心系统对该电站的遥控功能.     

电站锅炉水冷壁爆管故障树分析

系统分析了引起电站锅炉水冷壁管爆管的因素,建立了以电站锅炉水冷壁管爆管为顶事件的故障树,并通过故障树分析得到各阶最小割集.采用近似计算方法,计算出基本事件的结构重要系数,确定影响电站锅炉水冷壁爆管的主要因素.为提高电站锅炉水冷壁的安全性和运行可靠性,提出了相应的预防措施.     

电渣炉爆炸故障树分析

爆炸是电渣重熔生产中破坏性最大的事故类型,它的发生主要与电渣炉使用的水冷件有关.根据电渣重熔车间部分电渣炉爆炸事故分析结果,结合电渣炉生产的实际情况,编制了电渣炉爆炸故障树.采用布尔代数的运算法则求得了电渣炉爆炸故障树的最小割集;通过计算各基本事件的重要系数近似值,确定了它们的重要度顺序.在故障树分析的基础上,提出了防止电渣炉爆炸事故的控制措施.     

非能动核电站全厂断电事故的非等压模拟比例分析研究

应用H2TS方法对非能动核电站的全厂断电(SBO)事故进行了比例分析研究.识别并选择了重要热工水力学现象建立相似准则.基于相似准则中的参数关系,提出非等压模拟非能动核电站SBO事故的原理和试验方法,并进行了失真评价和程序预分析.结果表明:温度是非能动核电站SBO事故分析的核心参数;降压、等温模拟方法复现了原型电站的重要热工水力学现象,基本无失真;降压、降温模拟方法因冷却剂的物性差异产生了较小失真,该失真在事故进程中逐渐减小;ADS阀门开启后,降压模拟自动过渡为等压模拟,各项关键参数与原型电站相等.     

锂电池储能电站一次调频设计优化及验证北大核心CSCD

一次调频是储能电站支撑新型电力系统稳定运行的关键技术。本工作研究了锂离子储能电站一次调频集成设计,包括响应时间和过载能力两方面的分析及优化,主要通过信息采集与传递、策略算法运算周期两方面缩短响应时间,通过储能变流器内部功率器件开关频率控制方案提升其过载能力,并通过20 MW/10 MWh锂电池储能电站实现了上述指标优化验证。结果表明,锂离子储能电站应用于一次调频工况时,变流器响应时间为60~80 ms,变流器过载能力30 s内均能达到150%,提高了储能电站功率性价比。该储能电站在孤网中的一次调频试验中可有效平滑频率波动,减少发电机组的动作频次,可为后续功率型储能电站设计提供思路。     

电力机车辅助控制单元事件记录功能的实现

从硬件及软件设计上介绍了电力机车辅助控制单元(ACU)事件记录功能的实现。该功能已通过试验验证并已装车运用,极大地方便了维护人员对机车运用中出现的问题进行分析和诊断。     

盘式磁流体发电机-蒸汽动力装置联合循环热力系统的分析与计算

本文以盘式磁流体发电机为系统的核心.对直接加热、间接加热和混合加热等三种不同氧化剂预热方式所组成的万千瓦级磁流体-蒸汽联合循环中间试验电站的热力系统进行了分析.计算了不同方案联合循环电站的效率,并分析了诸因素的影响.     

鄂坪电站#2机PT断线保护动作致机组事故停机的分析

针对鄂坪电站首台机组投产不久出现 "PT断线"故障引起失磁保护误动致机组事故停机高速加闸现象,分析了事故的成因,提出了防范措施,消除了机组安全运行隐患,同时也为后续机组的安装提供了有益的借鉴.     

高压变频调速装置监测系统的设计与实现

结合三电平高压变频调速装置的结构特点,对其运行状态在线监测系统的功能需求进行了分析探讨。提出了监测系统的硬件构成方式和功能配置方案。介绍了监测系统的基本硬件结构、监测量的组成、运行数据记录格式以及相关软件的设计特点和实现方法。     

A critical review on cathode materials for steam electrolysis in solid oxide electrolysis

The major technologies being considered for the green hydrogen production are polymer electrolyte membrane (PEM) and solid oxide electrolysis (SOE). While PEM electrolysis technology is nearing commercialisation with units now being globally installed at tens of MW scale, SOE technology is still under development with units available only at 100s of kW scale and at much higher costs per kW. SOE due to its high operating temperatures (close to 800 °C) has the potential to reduce the electric energy input by up to 30% for the hydrogen production per tonne by using the low-cost thermal energy input available from the industrial or downstream synthesis processes. The SOE cathode, where steam electrolysis occurs, plays a crucial role in dictating the cell voltage losses and the stability of the cell operation that eventually has a large impact on the SOE efficiency and lifetime. The current state-of-the-art cathode materials based on Ni-YSZ pose many challenges. There is, therefore, a global effort to find alternative cathode materials suitable for steam electrolysis in SOE. This review critically reviews novel nanoengineered cathode materials and points to the fact that such materials synthesized using infiltration and exsolution techniques, in combination with advanced materials characterisation like high-temperature scanning probe microscopy and in situ Raman spectroscopy can be a right approach to find the suitable cathode materials for steam electrolysis in SOE. This, however, may need to be combined with a techno-economic analysis to provide the technical and economic viability of these materials for the SOE commercialisation.     

An SOE estimation model considering electrothermal effect for LiFePO4/C battery

The state of energy (SOE) is an important performance parameter and evaluation index for LiFePO₄/C battery since the available energy can be known more intuitively through SOE compared with state of charge (SOC). First, in order to improve the estimation accuracy of SOE, a novel estimation model combining electrical energy and thermal energy is put forward by studying the effects of discharge rate to the change laws of all kinds of energy inside the battery cell. Moreover, the concepts of unavailable energy E_u, maximum allowable energy E, and discharge energy efficiency η are originally proposed based on the analysis of energy consumption. Second, the parameter of actual maximum energy and energy consumption revised by the case of LiFePO₄/C battery can give an example to show the specific steps for improving the estimation accuracy of SOE during any integration time by using the novel SOE estimation model. Lastly, 2 international standard test experiments of EV are conducted to show the correction of SOC can efficiently limit the error below 4.6% and also indicate the novel SOE estimation method suitable for application area.     

Trade-off designs and comparative exergy evaluation of solid-oxide electrolyzer based power-to-methane plants

Solid-oxide electrolyzer (SOE) based power-to-methane (PtM) system can efficiently store surplus renewable power into synthesis natural gas by electrolysis and methanation. The system performance depends on the operating point of the electrolyzer and system design, particularly the heat exchanger network. In this paper, we investigate a SOE based PtM plant with a fixed-bed catalytic methanator and a membrane module for methane upgrading. A top-down approach is first employed to derive optimal system designs step by step from the system concept, to optimal conceptual designs with the trade-off between system efficiency and methane yield, to design-point selection and heat exchanger network design. Then, exergy evaluation with the exergy calculated into thermal – mechanical – non-reactive – reactive parts is applied to the derived four specific system designs to understand how exergy dissipation and performance of the overall system and each component vary from one to another. The results show that the system efficiency can reach between 80 and 85% (HHV) or 75–80% (LHV) when operating SOE with an inlet temperature of 700 °C and a utilization factor over 60%, above which electrical steam generation can be avoided and the steam can be generated by the heat from methanation reaction (around 80–85%) and anode outlet (15–18%). The system's exergy efficiency can achieve around 75–80% with the input exergy mainly destructed within the SOE (25–35%), methanator (25–35%) and heat exchangers (10–17%). However, exergy efficiencies of the SOE and methanator are high, over 90%. Depending on the temperature level of the cold stream and the temperature difference, heat exchangers generally have an exergy efficiency of over 50–80%. The electrical steam generator can only achieve an efficiency of around 20% and leads to a significant drop of system efficiency if employed; however, small electrical heating to reach the desired SOE inlet temperature, although bad, is acceptable. Therefore, one preliminary design guideline for such systems should be the avoidance of electrical steam generation.     

Air variation in SOE: Stack experimental study

Solid oxide electrolyzer are the electrolysis technology that can achieve higher efficiency and power densities. This study aims to analyze the role of air when used as a sweep gas in the oxygen electrode of a SOE. Based on experimental activity on a SOE stack, both polarization and constant utilization tests were performed changing the air flow rate in the stack. Due to air reduction, oxygen concentration of off gasses was increased from 25% up to 50%. All experimental results indicated that, reducing air flow down to 9% of nominal value, the effect on performances is negligible and variation of voltage is maintained below 2%. Thermoneutral condition was achieved at 500 mA cm^?2. Advantages of air reduction in SOE operation stand in both capital and operation costs. System design is simplified, ancillary consumptions are reduced and, in view of oxygen as a by-product, high oxygen concentrated off gases are produced with lower energy request for possible O₂ separation.     

二次光学元件侧面溢胶对聚光光伏组件光学效率的影响

基于全反射原理,该文理论研究二次光学元件在使用光学胶贴装过程中,二次光学元件底部侧面溢胶对接收器组件光学效率的影响。模拟分析3种不同二次光学元件的侧面溢胶高度对光学效率、接收角和温度变化的影响。结果表明,对于球透镜二次光学元件,光线在其传输过程中以折射为主,可有效减小侧面溢胶产生的光损失。对于平顶四棱锥镜,为减小侧面溢胶对光线的损失,在封装工艺过程中应严格控制侧面溢胶的高度,或优化设计侧面的倾斜角度。     

Co‐electrolysis of water and CO2 in a solid oxide electrolyzer (SOE) stack

Solid oxide electrolyzer (SOE) can operate in co‐electrolysis mode of H₂O and CO₂ because of the high operating temperature and the nickel‐based fuel electrode material. In this configuration, the fuel electrode is fed with a mix of steam and carbon dioxide that is converted through electrolysis reactions into a syngas that can be further upgraded to other carbon fuels. This technology can lead to interesting scenarios in the field of energy storage and CO₂ reuse. SOE performance in terms of syngas quality and chemical equilibrium is presented in this study. An experimental test on a four‐cell stack was performed to evaluate which are the effects of inlet gas composition and current density on the output syngas composition and on the thermal balance of the stack. Results were analyzed with the support of a thermodynamic model that aims to demonstrate that equilibrium condition is reached within the stack for all the involved reactions including reverse water shift. Also, we show that there is a direct relation between inlet and outlet compositions. For each composition, current density for thermoneutral condition was calculated obtaining values in the range of 377–493 mA/cm² depending on the composition. Such results permit to study SOE integration in a complete process for energy and CO₂ storage. Copyright © 2015 John Wiley & Sons, Ltd.     

750kV 官亭变电站综合自动化系统的现场检验探析

综合自动化系统是超高压变电站的重要组成部分。规范开展变电站综合自动化系统检验,是确保超高压变电站安全稳定运行的重要环节。对750kV官亭变电站综合自动化系统现场检验的具体开展情况进行了阐述。从遥测、遥信、SOE分辨率、系统性能、遥控、同期6个项目的测试方法入手,结合相关规程要求和目前系统中检验仪器的使用．对变电站自动化系统检验进行探讨。     

某抽水蓄能电站防水淹厂房关键技术研究

为提升抽水蓄能电站防水淹厂房的技术措施,结合工程实例,在分析顶盖螺栓断裂原因,确定设计安全裕度后完成了螺栓结构优化选型设计;从调速系统设置液压冗余回路、进水球阀控制柜布置、事故工况下尾水闸门启闭机可靠动作等方面开展了一系列电站防水淹厂房设计优化;提出了整套现场一管双机甩负荷试验逐级反演预测与分析方法,解决了随机水压脉动无法准确计算的问题,有效降低了试验安全风险。研究成果对于通过技术手段有效提升抽水蓄能电站本质安全具有指导意义。     

AP1000安全壳的优越性分析

福岛事故后,公众对于核电厂的安全性更加关注。而反应堆安全壳作为核电站最后一道安全屏障,其主要功能是能够在反应堆正常运行期间及事故工况下包容壳内的放射性物质,以避免对周围环境及社会公众造成危害。主要介绍第三代核电站AP1000的安全壳系统,并通过与现有二代堆安全壳对比的方式来论述AP1000安全壳系统的优越性。