水氢氢冷却发电机氢气纯度下降分析及对策

Analysis on drop of hydrogen purity of generator cooled by water-hydrogen-hydrogen and its countermeasures

发电机氢气系统中氢气纯度和湿度是2个重要指标。针对华能国际井冈山电厂1号国产引进型300MW发电机检修后氢气纯度下降过快的问题,通过对密封油系统和密封瓦结构进行分析,寻找解决问题的方法。对系统设计和运行中存在的问题和隐患,如平衡阀的不平衡导致空、氢侧窜油,过量的氢侧油箱补油,氢温和密封油温偏高等进行了改造及优化调整,控制了氢气纯度下降的速度,使发电机补氢量稳定在优良范围内。同时结合国产引进型300MW双流环密封瓦结构的特点,提出氢气系统运行和检修维护中应注意的事项。

According to the problem of drop of hydrogen purity for No.1 generator unit in Jinggangshan Power Plant,the hydrogen characteristics and the structure of oil-seal bearing and oil-seal system were analyzed. It was found that there exist some problems and incipient faults in the oil-seal system of the generator. After adjustment and reformation and optimization, the dropping rate of the hydrogen purity was controlled, which is adjusted from 1.4% per day to 0.08% per day. The consumption of hydrogen, which results from the purity of hydrogen drops, decreases from 70 m3 per day to 5 m3 per day and is within the better range. Considering the characteristics of structure of sealing bearing of 300 MW generator imported in technology and made in China, the proceedings that should be paid attention to in the operation and maintenance of the hydrogen system are presented. The description of the characteristics of hydrogen and the analyzing process and conclusion of the drop of the hydrogen purity can provide consultation for safe operation of the hydrogen system of the other same type of 300 MW generator cooled by water-hydrogen-hydrogen.