超临界机组锅炉高温再热器爆管分析

Analysis on Tube Burst in Boiler High-temperature Reheater of Supercritical Unit

某发电公司1900吨锅炉高温再热器(TP347H)进口段于168试运行期间爆破,爆口张开很大成喇叭状,并从喇叭口中部断成二截。笔者通过宏观检查、化学成份分析、金相检测等项目试验分析,得出:某发电公司高温再热器爆管原因为长时加短时超温爆管,为异物堵塞造成。并介绍了长时超温即蠕变断裂机理——应力集中断裂机理。

The inducer of a 1900t boiler high - temperature reheater （TP347 H） burst in supercritical unit of a power plant during 168 pre-operation, the site of burst was trumpet-shaped and the trumpet broke into two pieces form center. Some conclusions are achieved by some experiments such as： macro inspecion, chemical constitution analysis and metallographic detection, etc. They are as follows： long- term and short-term over-temperature and foreign body obstruction are the reasons of bursting. And the mechanism of creep fracture and stress concentration fracture is long-term overtemperature.