压水堆核电厂压力容器开盖时刻主冷却剂放射性浓度控制要求研究

压水堆核电厂停堆开盖时刻主冷却剂放射性浓度限值是核电厂的重要设计参数。本文基于停堆开盖后厂内辐射风险来源分析,建立了适用于压水堆核电厂停堆压力容器开盖时刻主冷却剂中的放射性浓度控制值评估方法,并采用欧洲第三代压水堆技术方案(EPR)堆型核电厂的设计参数对建立的方法进行了验证。验证结果表明:基于此方法得出的停堆开盖限值与EPR堆型核电厂原设计较接近。     

浙江省火力发电机组非计划停运统计及预防

通过对2015—2018年纳入浙江省技术监督管理系统的火力发电机组非计划停运事件的统计与分析,找出影响机组运行可靠性的主要故障原因和薄弱环节,为发电厂增强设备故障预防,加强运行、维护与管理等方面指明方向,提供建议及参考依据。     

SO2高温风机频繁跳车原因分析和处理

详细介绍了某300 kt/a铜冶炼工程SO2高温风机发生多次因润滑油压波动导致的跳车情况。对5次跳车故障进行了故障排查及原因分析,最后确定引起油压信号虚假波动的原因在于油压信号传输电缆,更换后故障排除。为类似故障分析和处理提供了经验。     

全氧燃烧玻璃窑炉的寿命浅析

通过对国内外部分全氧燃烧玻璃窑炉的寿命统计,非正常停炉和常见故障等问题分析,找出影响窑炉寿命的因素,提出要以规范化、科学化、系统化的思维,通过新材料、新技术、新工艺的运用有效延长全氧燃烧玻璃窑炉的寿命,对目前全氧燃烧窑炉的建设、推广应用有积极的参考价值。     

给水泵失电导致机组停机的技术分析

针对一台200 MW火力发电机组电动给水泵突然失电后引起直流锅炉灭火、机组停机事故,从给水泵及直流锅炉的水动力特性方面着手,分析了事故过程和事故原因,并提出了相应的安全技术防范措施,以确保机组安全稳定运行.     

基于网络控制的电机软启动器故障分析与控制系统改造

某公司低压电机应用某合资品牌软启动器配合网络完成启停及反馈控制方式,正常运行时频繁发生软启动器无故障报警停机。针对这一现象进行深入分析、总结,并对其进行国产化改造,以保证设备运行可靠性及生产的稳定性。     

TD-LTE主设备节能新技术简介

如何在节能减排的大背景下,不断开拓新思路、运用新技术,在不影响网络质量的情况下尽可能的提升设备能效是网络发展的必由之路,本文重点介绍了应用于TD-LTE主设备的几种节能新技术,通过对4G系统架构的分析,从硬件和软件2个方面着重阐述了新技术的原理及节能效果。     

The Internet shutdown muzzle(s) freedom of expression in Ethiopia: competing narratives

Freedom of expression is a foundational stone for democracy and embraces a number of other rights, including – freedom to seek, receive, and impart information using any medium. Around 16 million Ethiopians, comprising 15.4% of the total population, use the Internet. The Ethiopian Internet shutdown saga has been marked by competing narratives. On one hand, the government has been using two governing narratives, i.e. national security narrative and ‘economic growth’ narrative to justify shutdowns of the Internet. But, the individuals’ self-expressions on social media find itself as competing narrative. Since 2016, the Internet has been closed more than six times under the cloak of national security, quelling rising protests, controlling strikes, and exam cheating. As such, freedom of expression of millions has been muzzled. The article argues blanket Internet shutdowns do not meet the caveats of human rights law.     

Effects of seismic and aerodynamic load interaction on structural dynamic response of multi-megawatt utility scale horizontal axis wind turbines

Horizontal axis wind turbines can experience significant time varying aerodynamic loads that has the potential to cause adverse effects on structural, mechanical, and power production. The progress in the wind industry has caused the construction of wind farms in areas prone to high seismic activity. With the advances in computational tools, a more realistic representation of the behavior of wind turbines should be performed. One of the simulation platforms was developed using the 5 MW NREL utility scale reference turbine model. The performed simulations will be used to evaluate the effects of aerodynamic and seismic load coupling on the power generation and structural dynamics behavior of this structure. Different turbine operational scenarios such as (i) normal operational condition with no earthquake, (ii) idling condition with the presence of seismic loads, (iii) normal operational condition with earthquake, and (iv) earthquake-induced emergency shutdown will be simulated with various loading conditions to show the differences in generated power and dynamic response. The results of this paper provide formulations for calculating generated power and design deriving parameters by considering different intensity measures. Moreover, the effects of aerodynamic damping and pitch control system are presented to shows reduction in the resulting design demand loads.     

压缩机控制及保护系统设计探讨

现今机组控制及保护系统的功能越来越强大,系统配置方案也有很大差别;所面对的业主要求、遵守的规范也不尽相同,机组控制及保护系统的配置应针对不同状况来确定。列举了几种类型的系统方案：机组控制功能与保护功能与工艺装置部分合用;采用独立的防喘振控制器结构;采用机组控制与保护功能集成在一起的独立系统;机组与安全有关的保护功能与工艺装置安全仪表系统共用,机组控制功能设置独立系统;机组的控制及保护系统均独立。通过各方案的比较分析,为各工程公司和用户提供比较全面的选择方案。