600MW CFB非金属膨胀节损坏原因分析及防范措施

Causes Analysis and Precaution on Damage of Non-metallic Expansion Joints in 600 MW CFB

针对锅炉外置床到炉膛非金属膨胀节在试运初期频繁出现异常,多次发生非金属膨胀节蒙布超温、烧坏和泄漏等问题,对非金属膨胀节的损坏原因进行了分析,采用了内部迷宫形密封结构,并对保温填料、蒙皮结构进行了改造,改造后的非金属膨胀节进行了密封试验。试验结过表明:该结构的改造不仅保证了机组在启停过程中锅炉与外置床连接处的三维膨胀,同时解决了非金属节内容易积灰、破裂、泄漏问题,延长了非金属膨胀节使用寿命,保障了锅炉安全。

In the initial operation stage of 600 MW CFB unit in the Sichuan Baima Demonstration Power Plant,frequent abnormity happened at the non-metallic expansion joint between the external bed of the boiler and the furnace such as the skin over-temperature,burnout,and leakage etc.. The causes leading to the above-mentioned problems have been analyzed,and retrofit scheme put forward,including employ of the Labyrinth Seal and adjustment of the insulation packing and the skin construction. The seal test results of the retrofitted non-metallic expansion joint showthat the modified structure not only controls the three-dimensional expansion between the external bed of the boiler and the furnace during the start or stop,but also solves the ash deposition,rupture,and leakage in the joint,prolongs the service life of the joint,consequently ensures the safety of the boiler.