300MW机组EH油动机异常处理

Exception handling of EH hydraulic servomotor in 300 MW unit

某电厂300 MW汽轮机投运时间不长便出现高调门油动机机构漏油、油质恶化、伺服阀卡塞、系统油压下降等异常现象,严重影响到机组的安全运行。分析并查找出现异常现象的原因是油动机密封圈溶解所致,而密封圈过早老化失效是油动机缸体温度过高造成的。通过采取在油动机上加装冷却块和降低油动机缸体温度等措施,有效地解决了油动机漏油和油质恶化等问题。

In a 300 MW steam turbine of a power plant,for shorter time after it was put into operation,some abnormal phenomena,such as oil leakage of hydraulic servomotor mechanism of high pressure regulating valve,the degradation of the oil quality,the jam of servo valve,the decrease of system oil pressure and others,were occurred;and these abnormal phenomena influenced on safe operation of the unit seriously.Based on analysis,it was found that the reason of the abnormal phenomena is dissolving of the seal ring of hydraulic servomotor;and premature aging and failure of the seal ring were caused by the excessive temperature of the cylinder body of the hydraulic servomotor.Some measures,such as adding a cooling block on the hydraulic servomotor and reducing the temperature of the cylinder body of the servomotor,were adopted;and the oil leakage of hydraulic servomotor and degradation of oil quality were solved effectively.