超临界670MW机组高温过热器爆管原因分析  

CAUSE ANALYSIS OF TUBE-BURST ON HIGH-TEMPERATURE SUPERHEATER OF HOME-MADE SUPERCRITICAL 670 MW UNITS

作　　者：刘爽[1] 赵永宁[1] 刘天佐 宫伟基 

机构地区：[1]山东电力研究院,山东济南250002 [2]华电潍坊发电有限公司,山东潍坊261201

出　　处：《热力发电》2010年第9期103-105,109,共4页Thermal Power Generation

摘　　要：对华电潍坊发电有限公司超临界670MW机组高温过热器爆管事故原因进行了分析。对爆管段及邻近管排相同位置的管段进行的宏观检查、金相检验及力学性能试验结果表明,弯头弯制工艺不良造成弯头两端流通面积减小,影响了蒸汽的流通,导致管子因长时间过热组织严重老化,进而造成爆管事故的发生。为此,采取更换所有高温过热器管排最内圈的弯头,运行过程严格控制受热面蒸汽和管壁温度,使高温过热器出口蒸汽温度左右偏差不超过5℃等措施,实施后未再发生爆管事故。The causes leading to tube-burst failures on high-temperature superheater of supercritical 670 MW unit in Huadian Weifang Power Generation Co Ltd have been analysed,the macroscopic examination metallographic test,and mechanical test of bursted tube sections and tube-sections on same location of the neighbouring tube pannels being carried out.Results show that the bad tube-bending technology has made the flow-pasage area at both ends of the bend to be reduced,affecting the flow of steam,leading to serious ageing of pipes due to overtemperature in long-terms,further resulting in occurrence of tube-burst.For this,countermeasures,such as all the bends on inner circle of the high-temperature superheater have to be replaced,the steam and tube-wall temperature of heating surface has to be strictly controlled in the course of operation,the difference of steam temperature at outlet of high-temperature superheater shouldn＇t be greater than 5 ℃ at left and right side,etc.,have been put forword.After implementation,the tube-burst failures haven＇t occurred again.

关 键 词：超临界机组 高温过热器 爆管 弯头 通流面积 过热 

分 类 号：TK223.32[动力工程及工程热物理—动力机械及工程]