125 MW热电机组DEH系统电液伺服阀异常堵塞的失效分析

Failure analysis on abnormal blockage of electro-hydraulic servo valve in DEH system of 125 MW thermal power plant

为解决某热电厂125 MW机组DEH系统电液伺服阀异常堵塞导致的失效问题,本文通过综合表征方法对失效电液伺服阀材质,宏微观形貌及高压抗燃油油品成分进行了分析。结果表明电液伺服阀阀杆表面质量不良是导致电液伺服阀多次堵塞失效的根本原因,最后针对实际工况给出了解决方案和预防措施。

In order to ascertain the root cause of abnormal blockage of electro-hydraulic servo valve in DEH system of 125 MW thermal power plant, matrix material, macro and micro morphology and compositions of fire-resistant oil were analyzed by comprehensive characterization methods. The results indicated that poor surface quality of the electro-hydraulic servo valve stem was the root cause of the failure. Countermeasures were thus put forward to avoid the recurrence of similar failure.