燃气轮机常工作在非额定负荷的工况，但实际电厂燃机部件损伤估计使用的等效运行小时数统计方法中并未详细区分负荷状态，导致燃机透平叶片的服役寿命评估偏离实际损伤状态。为了提升透平叶片服役寿命评估的准确性，将运行负荷分为0~60%、60%~85%和85%~100%三个负荷区间，以区间上限表征该负荷区间的状态，基于三个负荷区间的透平叶片的边界参数，研究运行负荷变化对透平叶片蠕变寿命和低周疲劳寿命的影响，并结合某燃机电厂两年实际运行工况的统计数据，对比研究现有方法与基于部分负荷工况的透平叶片损伤寿命评估值。结果表明，60%负荷和85%负荷的5万小时最大蠕变应变分别是额定负荷设计工况的0.83和0.97倍，低周疲劳寿命分别是设计工况的4.01和1.78倍。基于部分负荷工况的总损伤比现有方法计算的总损伤降低了29.3%；通过与实际运行机组现状对比分析，认为所提出的改进方法对问题的描述和计算更加精准，分析结果更加可靠，可为定制化检修服务提供依据。

Gas turbines often operate under non-rated load conditions. However, in the statistical methods for estimating component damage of actual power plant gas turbines, load states have not been detailedly distinguished, resulting in deviations of the service life assessment of turbine blades from the actual damage status. To enhance the accuracy of the service life assessment of turbine blades, the operating load is divided into three load intervals: 0~60%, 60%~85%, and 85%~100%. The upper limit of each interval represents the state of that load interval. Based on the boundary parameters of turbine blades in these three load intervals, the influence of operating load variations on the creep life and low-cycle fatigue life of turbine blades is investigated. Additionally, combined with the statistical data of the actual operating conditions of a certain gas turbine power plant over two years, the existing methods and the damage life assessment values of turbine blades based on partial load conditions are compared and studied. The results indicate that the maximum creep strains at 50,000 hours for 60% and 85% loads are 0.83 and 0.97 times that of the rated load design condition, respectively, and the low-cycle fatigue lives are 4.01 and 1.78 times that of the design condition. The total damage based on partial load conditions is 29.3% lower than that calculated by the existing methods. Through comparative analysis with the actual operating status of the units, it is considered that the proposed improved method provides more precise descriptions and calculations of the problem, and the analysis results are more reliable, which can provide a basis for customized maintenance services.

上海市科委2020年度“科技创新行动计划”社会发展科技攻关项目