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1、专业好文档发电机氢气纯度下降的原因分析及对策发电机氢气纯度下降的原因分析及对策杨建安陕西电力科学研究院 摘要摘要： 某电厂 2 号发电机组从试运开始，就一直存在发电机氢气纯度缓慢下降趋势，通过 多方面列举分析、调整，逐步排除找出问题根本原因，提出对策并解决了问题。关键词关键词：发电机 氢气纯度 密封瓦0 0前言前言某电厂 2 号发电机组，为国产 300MW 水-氢-氢冷却方式，从 2010 年 9 月份调试投运后， 氢气纯度就缓慢下降，每天降低 1%。通过多方面列举分析、调整，逐步排除找出问题根本 原因，提出了对策并解决了问题。1 1系统概况系统概况氢气来自于厂制氢站，经由管路系统送至发电机底
2、部，通过氢气进口阀进入发电机内 部。空、氢侧密封油的设置为双流环式密封瓦，空、氢侧密封油油路的分开是为了防止氢 气受到含空气和湿气较多的空侧密封油的污染。主要通过调整氢侧密封油泵出口再循环阀使空、氢侧密封油压基本一致，同时通过调 节氢侧密封油平衡阀下部顶针顶起高度，从而使密封瓦处的空、氢侧密封油压力达到平衡， 以使密封瓦中间环处的空、氢侧密封油串流量达到一个较小的水平（通常是在5cm 水柱以 内，其中“”表示氢侧密封油压高、 “”表示空侧密封油压高） 。当密封瓦处的空、氢 侧微差压调整好后，由于平衡阀平衡点已经设定好，当空侧密封油压改变时平衡阀自动跟 踪调节氢侧密封油压使空、氢侧微差压保持不变
3、，来保持发电机内氢气压力和纯度。2 影响发电机氢纯度的因素影响发电机氢纯度的因素2.1 发电机严密性差漏氢氢系统存在漏点，致使氢压下降，纯度下降，进行检漏发现气密性良好。密封瓦密封 效果下降，起不到密封效果，致使氢气从氢侧漏至空侧，在发电机密封油排大气处测量没 有氢气溢出。2.2 氢气气源氢气源纯度低，充入发电机后必然影响氢气纯度，核查化验气源纯度达到 99%。2.3 密封油含水对氢气纯度的影响排烟风机出力不足或不运行会造成更多的空气和湿气溶入空侧密封油中，这样极少量 的窜油量就会使氢气纯度出现较大的下降。氢冷器的泄漏或渗漏主要造成氢气湿度的恶化，但由于物理交换的不可避免性，水中 的空气会析出
4、，氢气纯度势必下降。经化学检测氢侧密封油水分超标，达到 300 微克/升。2.4 密封油含空气对氢气纯度的影响专业好文档2.4.1 密封瓦空氢侧窜油 2.4.1.1 压差阀、平衡阀压力取样管存在节流造成压差阀、平衡阀自动跟踪不正常 正常情况下密封瓦中的空侧和氢侧密封油具有几乎相同的压力，空侧和氢侧密封油各 自保持相对独立的状态进行循环。密封油系统的平衡阀跟踪不好，或是由于平衡阀空侧、 氢侧压力取样管中的压力损失不同(虽然从表计上观察空氢两侧的密封油压是平衡的，而实 际上在密封瓦处的空、氢侧密封油存在一定的压差)，均会造成空侧与氢侧密封油在密封瓦 中的压力不平衡，导致空氢侧窜油。2.4.1.2
5、差压阀和平衡阀工作不正常 大型机组要求差压阀具有良好、灵敏的跟踪性能和富裕的调节范围。维持油氢差压的 任务是由差压阀来完成的。如果差压阀工作不正常将可能出现密封油直接进入发电机内的 现象。同时由于差压阀工作不正常，会引起平衡阀做出相应的跟踪调整，从而加速了空氢 侧密封油的窜流。 2.4.1.3 密封瓦间隙超差引起密封油窜流 密封瓦间隙超差将会引起平衡阀和压差阀自动跟踪困难，导致密封油窜流。 2.4.2 氢侧回油箱长期补油或排油运行 氢侧回油箱中的自动补排油阀故障造成密封油箱长期补油或排油运行，导致含有空气 的空侧密封油进入密封油箱后空气直接析出进入发电机。3 3 采取对策采取对策针对发电机组存
6、在的问题，依照以上原因，采用排除法，进行系统分析。首先从气源 入手，多次对制氢站来气检测，纯度均达到 99%，说明氢气源可靠。通过观察氢压下降速度，发现只有氢气纯度下降，没有氢压下降现象，排除了系统漏 氢的可能。对油质含水检查发现密封油水分含量超标，采取开大排烟风机出口开度，并且进行机 组在线滤油除水，连续投入机组氢气干燥器，氢气湿度、密封油指标全部合格后，氢气纯 度仍然下降，排除水分的影响。调整氢侧密封油压大于发电机内部氢气压力，仍然无效。调整氢侧密封油泵出口油压 大于空侧密封油泵出口油压，减少空侧向氢侧窜油量，实际氢气纯度下降速度没有改变， 排除密封瓦窜油的可能。检查氢侧回油控制箱，发现排
7、油管道温度和氢侧密封油泵入口油管道温度接近，怀疑 氢侧回油箱中的自动补排油阀故障造成密封油箱长期补油或排油运行，检查排油阀阀位不 对，在补油阀控制油位高度时不能完全关闭，调整后，机组氢气纯度不再下降，保持良好。4 4结束语结束语机组发生类似故障时，首先采用分析排除法，由繁到简。应当从污染源查找入手，查 找系统运行参数，寻找可能造成氢气污染的设备环节，不正常运行参数，分析原因，逐个 排除，找出根本原因解决问题。专业好文档参考文献参考文献：略作者简介作者简介：杨健安（1970-） ，男，高级工程师，从事汽轮发电机组调试及技术服务工作。专业好文档Editors note: Judson Jones
8、is a meteorologist, journalist and photographer. He has freelanced with CNN for four years, covering severe weather from tornadoes to typhoons. Follow him on Twitter: jnjonesjr (CNN) - I will always wonder what it was like to huddle around a shortwave radio and through the crackling static from spac
9、e hear the faint beeps of the worlds first satellite - Sputnik. I also missed watching Neil Armstrong step foot on the moon and the first space shuttle take off for the stars. Those events were way before my time. As a kid, I was fascinated with what goes on in the sky, and when NASA pulled the plug
10、 on the shuttle program I was heartbroken. Yet the privatized space race has renewed my childhood dreams to reach for the stars. As a meteorologist, Ive still seen many important weather and space events, but right now, if you were sitting next to me, youd hear my foot tapping rapidly under my desk.
11、 Im anxious for the next one: a space capsule hanging from a crane in the New Mexico desert. Its like the set for a George Lucas movie floating to the edge of space. You and I will have the chance to watch a man take a leap into an unimaginable free fall from the edge of space - live.The (lack of) a
12、ir up there Watch man jump from 96,000 feet Tuesday, I sat at work glued to the live stream of the Red Bull Stratos Mission. I watched the balloons positioned at different altitudes in the sky to test the winds, knowing that if they would just line up in a vertical straight line “we“ would be go for
13、 launch. I feel this mission was created for me because I am also a journalist and a photographer, but above all I live for taking a leap of faith - the feeling of pushing the envelope into uncharted territory. The guy who is going to do this, Felix Baumgartner, must have that same feeling, at a lev
14、el I will never reach. However, it did not stop me from feeling his pain when a gust of swirling wind kicked up and twisted the partially filled balloon that would take him to the upper end of our atmosphere. As soon as the 40-acre balloon, with skin no thicker than a dry cleaning bag, scraped the g
15、round I knew it was over.专业好文档How claustrophobia almost grounded supersonic skydiver With each twist, you could see the wrinkles of disappointment on the face of the current record holder and “capcom“ (capsule communications), Col. Joe Kittinger. He hung his head low in mission control as he told Ba
16、umgartner the disappointing news: Mission aborted. The supersonic descent could happen as early as Sunday. The weather plays an important role in this mission. Starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will cli
