运用θ函数法实现锅炉承压部件寿命的在线监测

Online Monitoring System of Boiler Pressured Part Lifetime Using θ-function Method

θ函数法是锅炉承压部件寿命评估发展到第四阶段的评估方法,与Larson-Miller相比具有精度高、外推时间长等优点。为了实现锅炉承压部件寿命的在线监测,本文以θ函数法作为基础算法,在VC编程环境下,将寿命预测步骤设计编写成计算机程序,实现了θ函数的数据拟合,并将拟合结果用于蠕变损耗分析;同时,给出了蠕变损耗的计算方法与步骤;最后,结合现场运行数据,运用θ函数法,对某电厂中材料为P91的高温过热器出口联箱进行蠕变寿命损耗的在线估算与预测,实现了θ函数法与现场实际的结合。

The θ-function method is used to calculate pressured parts inside boiler as the fourth stage on the lifetime evaluation and has the advantages of high precision and long extrapolation over Larson-Miller extrapolation formula.In order to achieve lifetime on line monitoring of pressured parts inside boiler,the lifetime prediction programs are designed and programmed using VC based on θ-function method,and the data fitting of θ-function is realized in this paper.Then the analysis on creep lifetime loss is conducted from the data fitting results and the calculating processes of creep lifetime loss are given.Finally,according to the operating data,the online evaluation is undertaken with θ-function method for creep lifetime loss analysis of a high-temperature superheater outlet header using metal P91 in a power plant.The θ-function method is used to evaluate pressured part lifetime loss in this power plant based on the practical operation data.