300MW机组排污膨胀器的事故分析及改造

分析了1台300MW机组定期排污膨胀器在运行中严重超压和排汽口严重带水的事故原因，通过计算及结构分析认为，其膨胀器结构不合理、容积不够和排汽口截面过小等是造成定期排污膨胀器在运行中严重超压和排汽口严重带水的事故原因。针对分析的结果，对排污膨胀器进行尺寸及结构上的改造，完成改造后，经过3年多的稳定运行表明，改造成果显著，并可在同类机组中推广使用。

Failure Analysis and Modification of the Blow-down Flash Tank of a 300 MW Unit

The periodic blow-down flash tank of a 300MW unit suffered serious overpressure and serious carry-over of water at an steam exhaust port during its operation. Through calculations and a structural analysis the causes of the failure were identified as irrational structure and insufficient volume of the flash tank as well as an excessively small section area of the steam exhaust port. In light of the results of failure analysis it was decided to change the flash tank dimensions and structure. Three years of stable operation after completion of the flash tank modification indicate that the implemented changes have brought about excellent results, showing promise of its prospective wide application in other analogous units.