410t/h锅炉点火风道膨胀节故障原因分析  

CAUSE ANALYSIS ON THE EXPANSION JOINT FAILURE OF 410 T/H BOILER IGNITION AIR DUCT

作　　者：李金月[1] 

机构地区：[1]中国石化北京燕山分公司,北京102500

出　　处：《石油化工设备技术》2016年第3期30-33,5,共4页Petrochemical Equipment Technology

摘　　要：从设备制造、安装及工艺操作三方面介绍了某厂410t/h锅炉点火风道膨胀节故障及处理措施。分析认为膨胀节制作过程中没按技术协议规定,即与烟气直接接触部位的金属材质性能不应低于0Cr25Ni20Si2,而是采用了普通不锈钢;在安装过程中,没有按设计要求预留80 mm的安装错位量,运行过程中膨胀节波纹管变形严重,内部浇筑料破损、脱落;在点火期间,由于燃烧器油枪额定出力过大,雾化空气的压力过低,轻柴油燃烧不充分,而且膨胀节相连的燃烧室温度超过膨胀节的设计温度,高温烟气进入膨胀节波纹管部位,最终导致膨胀节破损。故障发生后对膨胀节进行矫正和补焊,修复破损的锚固钉及浇筑料,点炉后满足锅炉运行的需要。建议根据锅炉的实际安装情况及工艺运行参数对膨胀节重新设计制造,并采用新型的密封形式,以避免高温烟气进入波纹管部位。This paper introduces the expansion joint failure of the 410t/h boiler ignition air duct in a factory and treatment measures from three aspects covering equipment manufacture,installation and process operation.According to the provisions of the technical agreement,the metal material performance of the joint point contacting flue gas directly shall not be lower than 0Cr25Ni20Si2.But ordinary stainless steel was used in the manufacturing process.During the installation process,the pre-dislocation amount of 80 mm was not set aside according to the design requirements,resulting in serious bellow deformation of expansion joint,internal casting material damage and falling off in the operation process.During ignition,the rated capacity of the burner oil gun was too large;the atomizing air pressure was too low;the oil combustion of light diesel was insufficient;the temperature of combustion chamber connected by expansion joints was higher than the design temperature;high-temperature flue gas entered into the expansion joint bellows.And these eventually led to expansion joint breakdown.After the breakdown,the expansion joints were rectified and repair welding was carried out;the damaged anchor nail and casting material were repaired.After ignition,the boiler met the needs of operation.It＇s suggested that expansion joint shall be designed and manufactured again according to the actual situation of the boiler installation and operation parameters;new type of seal shall be used to avoid the high-temperature flue gas entering the corrugated tube parts.

关 键 词：膨胀节故障 耐高温材质 预错位 高温烟气 密封 

分 类 号：TK228[动力工程及工程热物理—动力机械及工程]