P22再热热段蒸汽管道长期运行后剩余寿命评估研究

Residual Life Evaluation of P22 Reheat Pipeline after Long-term Operation

对某电厂600 MW机组17万小时长期运行后的P22再热热段蒸汽管道进行了取样试验,并根据试验结果进行了剩余寿命评估工作。结果表明,P22再热蒸汽管道组织已发生明显老化,材料的各项力学性能均有所下降,以上均为P22管道高温高压条件下长期运行后的正常现象。根据高温持久试验数据可计算出在569℃和4.57 MPa工况下,再热热段蒸汽管道母材和焊缝剩余寿命均大于10万小时。按平均运行小时数7 000 h/y估算,尚有10年以上的蠕变剩余寿命。

The sampling test was carried out on the P22 reheat steam pipeline for 170 000 h a long-term operation in a 600 MW power plant. And residual life was evaluated according to the experiment results. The results show that P22 reheat steam pipeline has serious aging, and the mechanical properties of materials decreases. But it＇s normal phenomenon for P22 reheat steam pipeline after long-term operation under the condition of high temperature and high pressure. According to the high temperature endurance test data, the residual life of P22 base and welded line are both more than 100 000 h under the working conditions of 569 ℃ and 5.47 MPa. According to the average operating hours of 7 000 hrs per year, the residual life of P22 base materials and welded line are both above 10 years.