新建超超临界机组锅炉及系统的清洁技术

Discussion on the cleaning technology for newly constructed ultra-supercritical boiler and its systems

目前新建超(超)临界机组频繁发生投产后不久便出现汽轮机叶片受损、效率明显下降的情况,说明现有的锅炉和系统内残留异物清除工艺和技术存在局限性。介绍了传统的新建机组的化学清洗、吹管、洗硅及带旁路清洗等的工艺原理和作用及这些工艺的不足之处和改进方向。总结了外高桥电厂三期工程在调试期间对酸洗、吹管和带旁路清洗等工艺进行的改进和创新,包括干态吹管、带旁路清洗工艺优化、实施汽轮机启动前的带旁路高动量冲洗等,在机组的运行实践中均取得了满意的效果。

Because of the limitations of present cleaning process and technology for the residues in the boiler and its system, the frequent erosions of the turbine blades and the apparent efficiency reduction in newly constructed ultra-supereritieal units appeared. The principles and the functions of the traditional chemical cleaning, steam blowing out silicon cleaning and flushing with bypass in the new units are introduced. The shortage and the improvement of these technologies are analyzed. Finally the technical improvement and innovation during the unit commissioning in Waigaoqiao Phase Ⅲ Project are pointed out, viz. the dry steam blowing, optimizing of flushing with bypass and high momentum flushing with bypass before the turbine start-up, which show the effectiveness in the unit operation process.