超超临界锅炉高温再热器HR3C管屏开裂分析及应力优化  

Cracking Analysis and Stress Optimization for HR3C Tube Panel of the High-temperature Reheater in an Ultra Supercritical Boiler

作　　者：刘长福 谌康 郭德瑞 杜双明 李帅 杨明昌 Liu Changfu;Shen Kang;Guo Derui;Du Shuangming;Li Shuai;Yang Mingchang(Datang Intelligent Energy Technology Research Institute,Beijing 100040,China;Shenzhen Energy Hopewell Power(Heyuan)Co.,Ltd.,Heyuan 517000,Guangdong Province,China)

机构地区：[1]大唐智慧能源技术研究院,北京100040 [2]深能合和电力(河源)有限公司,广东河源517000

出　　处：《发电设备》2023年第2期82-88,共7页Power Equipment

摘　　要：某超超临界锅炉二次高温再热器HR3C管屏投运约2 000 h时在冷弯管内弧处发生开裂,从应力水平研究分析其原因。结果表明:弯管金相组织正常,室温抗拉强度合格;裂纹处具有明显的沿晶氧化缺陷特征。弯管截面的椭圆度对弯管应力的影响较大,同时弯管冷弯后未进行固溶处理消除残余应力,在运行过程中促使弯管沿晶氧化缺陷的产生与扩展,最终导致管屏开裂。在实施弯管截面椭圆度控制、固溶处理和安装改进等优化措施后,管屏在后续运行中未发生开裂。To solve the problem of the cracking occurring at the inner arc of the cold bend tube of the secondary high-temperature reheater in an ultra supercritical boiler with the operation time of about 2 000 h, researches and analyses were conducted on the reason according to the stress distribution. Results show that, the bend tube has the normal metallographic structure and the qualified tensile strength at room temperature. It is found that the cracking has the obvious characteristics of intergranular oxidation defects. The stress is significantly influenced by the ellipticity of the bend section, while the residual stress caused by the lacking step of solution treatment for the cold bend is still existed. The generation and expansion of the intergranular oxidation defects is promoted by the residual stress, which finally leads to the cracking of the tube panel during operation. There is no cracking occurring at the tube panel during operation with following optimization measures, such as controlling the ellipticity of the bend section, carrying out the solution treatment, improving the installation, etc.

关 键 词：锅炉 管屏 HR3C 开裂 应力 

分 类 号：TK225[动力工程及工程热物理—动力机械及工程]