基于Z型结构过热器流量分配不均引起的爆管原因分析

为了防止电厂蒸汽锅炉高温过热器冷段受热面发生爆管事故,以漳泽发电厂4#蒸汽锅炉为对象,通过调阅该锅炉的负荷工况记录、查阅设备图纸以及对爆管采用金相、壁温试验分析和水力偏差分析炉等方法,对高温过热器冷段受热面爆管的原因进行了多方位多角度研究分析。分析表明:从锅炉1/4部分看,高温过热器冷段受热面属曲型的"Z"型分布,在热态超低负荷较长时间运行时,管内流量不均是爆管的主要原因,运行中减温系统操作不合理是爆管的重要原因。对此提出防止爆管的技术措施。采用应对措施后,4#蒸汽锅炉再未发生过热器爆管事故,锅炉运行的安全性大大提高。此项技改对保证同类型锅炉平稳运行有重要的指导意义。

Analysis of the Pipe Burst Based on the Non-uniform Flow of the Z-type Superheater

To forestall pipe burst accidents happened in the heating surface in the superheater in a power plant boiler,the paper,taking No.4 boiler in Zhang-zhe power plant as example,collects the boiler's workinglogs,reads equipment blueprints,and analyses the broken pipe's metallic structure,furnace temperature and water deviation.This analysis is of multiple-aspect.It shows that the one-fourth part of the boiler——the heating surface in the superheater is distributed in Z-type.when the pipe operates under the condition of lower load in hot and long-time operation,the flow in the pipe is uneven,which causes the pipe burst.The paper finds that the improper operation of the desuperheating system also makes a difference on the pipes.After the counter-measure was taken,No 4 boiler avoided this accident.This technical innovation is meaningful to the stable operation of this type of boiler.