300MW机组停运时发电机进油的原因分析

The reason analysis of the oil entering the generator when the 300MW units Shutdown

由于双流环密封油系统技术的日趋成熟，当前大多300MW及以上的大容量汽轮发电机都采用了双流环密封油系统。双流环密封油系统既能防止发电机内部氢气外泄，又能防止发电机外部的空气和潮气进入发电机，污染发电机内的氢气和降低发电机定子和转子绕组绝缘。但是如果对其结构不了解或操作不当也有可能造成发电机进油事故，尤其是在机组停运，发电机内部为常压状态时更容易发生发电机内部进油事故。对两起300MW机组发电机在停运大修过程中进油事故的原因进行分析。

Because the technology of double - current link oil sealing system is ripened day by day, recently most turbo generatorswhich capacity is 300MW or over 300MW use double - current link oil sealing system currently. The double - current link oil sealing system can both prevent the hydrogen in generator releasing and the atmosphere and other humidity gas entering the generator, which win pollute the hydrogen in generator and reduce the generator stator and the rotor winding insulation proporty. Not understanding the structure or operating inaccurately, it is possible to cause the oil entering the generator, especially in the condition when units Shrtdown and the state inside the generator is in normal pressure state. The article analyzed the reasons which cause oU entering the generator when the 300MW units Shatdown by two examples.