密封油系统调整及发电机进油分析

介绍了新疆东方希望有色金属有限公司自备电厂1#机组发电机多次进油情况,列举了在机组试运期间由于运行人员不按说明书及操作规程要求导致发电机进油的案例,为新建机组单流环式密封油系统的调试提供可借鉴的经验,以避免此类事故再度发生.     

1000MW机组发电机密封油管道安装位置对氢气泄漏的影响分析

介绍了对某1 000MW电厂发电机氢气泄漏严重问题的检查情况,通过对发电机密封油及氢气系统的研究,发现了由于密封油系统油氢差压阀的两根信号取样管(氢汽压力和密封油压力信号取样管)的安装位置问题而导致取样管内油静压无法合理消除和补偿情况,导致了发电机氢气泄漏量大,并提出了改进措施。     

优化600MW机组密封油抽真空系统提高设备稳定性

本文通过对国投钦州发电有限公司630MW机组密封油真空油箱真空值偏低原因分析得知,真空低是由于设备服役时间长效率降低加上原设计理念落后造成,该设备为进口设备,维修更换费用高昂且无备用设备,原设计需进行定期排废油补充新油,长期真空不合格使得密封油中水分无法完全析出,存在污染发电机内氢气及腐蚀密封瓦的危险,影响机组运行的稳定性。为解决这一难题,对密封油抽真空系统进行优化改善,通过综合分析,提出并实施了一系列优化改善措施,从根本上解决了密封油真空油箱真空值偏低的问题。     

660 MW氢冷发电机氢气纯度下降的原因分析及处理

发电机氢气纯度是保证冷却效果和通风效率的一个重要指标。针对湖南某厂#2发电机氢气纯度下降过快的问题,通过对影响氢气纯度下降的各种因素的分析,确定了氢气纯度下降的原因,并在检修中彻底予以解决,氢气纯度下降的速率得到有效控制,使发电机补氢量稳定在优良范围内。     

600MW氢冷发电机氢气纯度下降的原因分析及处理

针对某电厂2号发电机氢气纯度异常下降的问题,对影响氢气纯度的各种因素进行了全面地分析,找出了氢气纯度异常下降的真正原因,彻底地予以解决.     

应对高碱值气缸油的副作用——二冲程十字头柴油机活塞杆密封系统

<正>发动机制造商和油品公司一致认为,为避免新一代长冲程低速发动机低速运行时出现冷腐蚀,需要一种高碱值气缸油。基于多年来二冲程十字头柴油机活塞杆密封、往复应用故障分析和转动密封故障分析经验,Marine Sealing Service公司(Mar Seal,该公司主要研发海事工业流体密封技术)研制出了RPDS alpha活塞杆密封技术。     

300MW汽轮机端部碰磨振动故障的诊断

某机组在基建调试阶段首次启动过程中,中速暖机1200r／min工况下振动缓慢爬升,15分钟后振动急剧增长,被迫打闸停机。通过试验分析,明确诊断出机组振动故障原因是活动式密封油挡发生碰磨所致。去掉活动式密封油挡后,再次启动完全消除了该机组的振动故障,使机组试运工作得以顺利进行。     

发电机双流环式密封瓦磨损事故的分析与处理

某电厂220MW机组发电机为三相两极同步发电机,转子绕组、定子铁芯及其他构件采用氢气冷却。2010年9月2日,发生双流环式密封瓦磨损造成氢气外漏,机组被迫停运事故。根据事故的发生及处理过程,深入分析事故原因,就应采取的解决方案进行讨论。     

汽轮发电机密封瓦引发的不稳定振动分析

为研究某大型汽轮发电机上发生的轴承振动周期性波动故障机理,以单流环式密封瓦为对象,应用Reynolds方程建立了密封瓦力学分析模型,分析了氢气侧压力对密封瓦工作状态的影响。考虑油膜流动热效应,建立了油膜温度分布求解模型。结果表明:在大偏心率、大油黏度和小密封瓦间隙下油膜温升较大;在轴颈同步正向涡动状态下,轴颈截面会出现温差,导致发电机转轴发生热弯曲;通过变密封油温试验确认了发电机振动周期性波动故障的原因,可采取减小轴颈晃度和不平衡引发的同步涡动、适当增大密封瓦间隙等措施解决了机组振动故障。     

发电机氢气纯度湿度不合格及发电机进油分析及防范

发电机进油以及氢气纯度、湿度不合格给大型发电机的安全稳定可靠运行带来潜在的危害.针对大型汽轮发电机运行中存在的氢气纯度和氢气湿度不合格、发电机内进油的原因、危害,重点阐述了如何防范发电机进油、提高氢气纯度、降低氢气湿度的措施.     

柴油机单刮油边螺旋撑簧油环的研究

柴油机螺旋撑簧油环采用单刮油边结构,并去除环体上的回油孔,从而有效地改善了环体的强度,使环体的轴向高度和径向厚度大幅度地降低.新设计的单刮油边螺旋撑簧油环在接触比压保持不变的前提下,明显地改善了对气缸壁的贴合性,且油环切向弹力下降40%～50%,从而降低了摩擦阻力.试验结果表明单刮油边螺旋撑簧油环可使柴油机保持较低的机油消耗率,并使燃油消耗率降低1.3%～3.2%.     

整体式发动机曲轴油封

本文介绍了一种整体式发动机曲轴后油封,应用于发动机曲轴后,其特点是集油封座、静密封（端面密封）、动密封（唇部密封）于一体,优点是简化装配和降低成本。同时,对其唇部采用不同密封结构时的加工制作工艺及性能特点进行了分析比较,为发动机密封技术的研究与发展提供参考。     

气缸盖罩橡胶密封圈的密封性能分析

利用有限元法对气缸盖-密封圈-气缸盖罩组合件进行螺栓预紧状态下的结构分析,得到了密封圈上的压力分布云图,发现密封圈主刃口的两个拐角处密封压力接近于零,不能有效地密封润滑油,与试验中该处漏油的实际情况一致。进一步的分析表明：漏油的主要原因是由于结构不对称,使得该位置缺少螺栓,导致密封压力接近于零。改进方案采取将气缸盖罩材质改为铝,将盖罩螺栓组中橡胶衬套改为减震弹簧等措施,大幅度地提高了最小密封压力,从而解决了密封问题。     

World energy analysis: H2 now or later?

This is a study of world energy resource sustainability within the context of resource peak production dates, advanced energy use technologies in the transportation and electricity generation energy use sectors, and alternative fuel production including hydrogen. The finding causing the most concern is the projection of a peak in global conventional oil production between now and 2023. In addition, the findings indicate that the peak production date for natural gas, coal, and uranium could occur by 2050. The central question is whether oil production from non-conventional oil resources can be increased at a fast enough rate to offset declines in conventional oil production. The development of non-conventional oil production raises concerns about increased energy use, greenhouse gas emissions, and water issues. Due to the emerging fossil fuel resource constraints in coming decades, this study concludes that it is prudent to begin the development of hydrogen production and distribution systems in the near-term. The hydrogen gas is to be initially used by fuel cell vehicles, which will eliminate tailpipe greenhouse gas emissions. With a lowering of H₂ production costs through the amortization of system components, H₂ can be an economic fuel source for electricity generation post-2040.     

140×10~4t/a加氢裂化装置循环氢控制分析

对高桥石化140×104t/a加氢裂化装置循环氢的操作和控制操作情况进行探讨。控制合理的氢油比,可以有效确保装置催化剂的长周期运行;合理的压力控制区间,能够在确保目的产品收率的前提下降低装置能耗;在一定压力范围内,裂化反应深度将增加,转化率得到提高,轻组分收率相应增加。但随着压力的上升,这种趋势趋于平缓。在以上分析的基础上,探讨了装置提高循环氢纯度的方法,确认新氢的使用、冷高分和热高分的温度控制,以及循环氢脱硫塔的操作,是影响循环氢纯度的关键因素。使用氢气纯度较高的制氢氢气,对提高循环氢纯度是有利的。高压分离器温度高,对减少氢损耗有利,温度低,对提高循环氢浓度及降低能耗是有利的。当加氢裂化装置加工的原料油硫含量在1.5%以上时,一般都增设循环氢脱硫设施,这样可保证循环氢纯度。列举了目前装置在循环氢运行中存在的主要问题,为石化行业同类装置的平稳操作提供帮助。     

Decentralized generation of electricity from biomass with proton exchange membrane fuel cell

Biomass can be applied as the primary source for the production of hydrogen in the future. The biomass is converted in an atmospheric fluidized bed gasification process using steam as the gasifying agent. The producer gas needs further cleaning and processing before the hydrogen can be converted in a fuel cell; it is assumed that the gas cleaning processes are able to meet the requirements for a PEM-FC. The compressed hydrogen is supplied to a hydrogen grid and can be used in small-scale decentralized CHP units. In this study it is assumed that the CHP units are based on low temperature PEM fuel cells. For the evaluation of alternative technologies the whole chain of centralized hydrogen production from biomass up to and including decentralized electricity production in PEM fuel cells is considered.Two models for the production of hydrogen from biomass and three models for the combined production of electricity and heat with PEM fuel cells are built using the computer program Cycle-Tempo. Two different levels of hydrogen purity are considered in this evaluation: 60% and 99.99% pure hydrogen. The purity of the hydrogen affects both the efficiencies of the hydrogen production as well as the PEM-FC systems. The electrical exergy efficiency of the PEM-FC system without additional heat production is calculated to be 27.66% in the case of 60% hydrogen and 29.06% in the case of 99.99% pure hydrogen. The electrical exergy efficiencies of the whole conversion chain appear to be 21.68% and 18.74%, respectively. The high losses during purification of the hydrogen gas result in a higher efficiency for the case with low purity hydrogen. The removal of the last impurities strongly increases the overall exergy losses of the conversion chain.     

A hydrogen economy and its impact on the world as we know it

An assortment of governmental, technological, environmental, and economic factors has combined to spur renewed interest in alternatives to petroleum, and especially in hydrogen. While there is no clear consensus on the viability of the technology, governments and corporations alike have vigorous hydrogen research programs. The result is that hydrogen may stand on the verge of becoming a true successor to oil. A transition from oil to hydrogen would alter familiar global economic and political structures in profound ways. The ramifications will influence developed and developing nations, oil importers, and exporters alike. New alliances among governments, corporations, and other groups may challenge existing notions of governance. Although a hydrogen-based economy may be decades away, the vision for it requires near- and mid-term thinking to manage the transition smoothly. Further, hydrogen is only a metaphor; any change from the current oil economy will entail dramatic changes to the global status quo that must be planned for now.     

改进柴油机螺旋撑簧油环性能的研究

根据活塞环／缸套快速磨损模拟试验结果,发现螺旋撑簧油环的磨损量较大。该油环磨损后随开口间隙的增大,其接触比压迅速降低,严重影响了其刮油能力。通过对油环结构的改进,在开口间隙增量为2mm时,改进后的油环接触比压比原环提高45．7％;通过快速模拟磨损试验发现铌铸铁油环耐磨性能比铬钼铜油环提高87．3％,并降低了油环的制造成本。装机使用说明,改进后的铌铸铁螺旋撑簧油环具有良好的使用性能。     

内燃机活塞环组润滑特性的综合分析

本文以作者的混合润滑模型MLM_2为基础,通过增加自动判别各环润滑油供应状况(即贫油还是富油)及环组间润滑油流动的子程序,实现了将环组的漏气、油膜厚度、瞬态摩擦功、润滑油流动及消耗机理等的系统耦合,从而为比较完整地评价环组的设计及工作情况提供了一种更为合理的分析手段。计算实例在文中给出。     

炼厂氢气资源优化浅谈

随着炼厂氢气耗量的不断增加,需要选用低廉的制氢原料,采用合理的制氢工艺技术,满足炼厂氢气需求.比较变压吸附、膜分离、深冷分离三种氢气提纯分离技术,对加氢等装置尾气中低浓度氢进行回收利用,能够合理利用氢气资源,有效降低生产成本.某炼厂选用焦化干气制氢后,与轻油制氢相比,原料成本下降,氢气纯度提高.根据各用氢装置的用氢压力、用氢量进行匹配,采用从高压到低压的一次通过式流程,只设置一台新氢压缩机,氢气逐级利用.不仅提高了氧气资源利用率,而且有效降低了炼厂综合能耗.采用PRISM膜分离器,从高达10MPa压力的冷高压分离器排放尾气中回收提纯氧气,回收提纯的氢气再回到新氢压缩机的三级人口升压后循环使用.废氧进行胺液脱H2S处理后,采用PSA技术进行废氢回收利用,PSA副产品解吸气升压后作为制氢装置的原料,节约了生产成本.