发电机氢气纯度不合格的原因分析及处理

Cause Analysis and Treatment of Unqualified Hydrogen Purity in Generators

发电机作为火力发电厂的三大主机之一,其地位相对重要,氢气作为发电机冷却介质,是必不可少的。如果机组运行中氢气纯度不合格,就有可能导致发电机冷却效率低、绝缘老化,若氢气中氧气含量超标,则可能发生发电机氢爆事故。发电机氢气纯度不合格,运行中只能通过降压排氢方式换氢。基于此,结合贵州西电电力股份有限公司黔北发电厂#3机组,分析单流环发电机氢气纯度不合格的原因可能是,由于密封瓦氢侧油挡间隙偏大、油氢差压过高,密封油通过密封瓦氢侧油挡进入发电机,造成氢气中空气或油烟含量增加,并提出运行中防止氢气纯度不合格的控制措施。

As one of the three main engines of thermal power plants,the status of generators is relatively important.Hydrogen is essential as a generator cooling medium.If the purity of hydrogen is unqualified during unit operation,it may lead to low cooling efficiency and aging insulation of the generator.If the oxygen content in hydrogen exceeds the standard,a generator hydrogen explosion accident may occur.If the purity of the generator hydrogen is unqualified,the hydrogen can only be exchanged by depressurization and hydrogen discharge during operation.Based on this,combined with Unit#3 of Qianbei Power Plant of Guizhou Xidian Electric Power Co.,Ltd.,the reasons for the unqualified hydrogen purity of the single-flow ring generator may be that the oil block gap on the sealing tile hydrogen side was too large,the oil-hydrogen differential pressure was too high,and the sealing oil entered the generator through the oil block on the sealed tile hydrogen side,resulting in an increase in air or oil smoke content in hydrogen.Finally,control measures to prevent unqualified hydrogen purity in operation are proposed in this paper.