多物理场作用下的燃气轮机高温叶片全运行周期寿命模型研究

For long-term operation, blades start to show some defects with increasing operating hours, such as fouling, erosion, corrosion, damage and tip clearance. As the basic unit components of gas turbines, the health conditions of blades directly affect the energy conversation efficiency and service life of the whole equipment. The process from first installation to scrap is blades’ whole operation life cycle. It is an effective way to establish the whole operation life cycle model of blades for real-time monitoring, troubleshooting and prevention, so as to improve the management of equipment. The current research on the whole operation life cycle model is mostly limited to a single subject, such as thermal effects or vibration effects. It lacks a profound analysis of this issue from the multi-disciplinary perspective. Meanwhile, the deterioration of blades influence on geometry variation of the blade surface is not taken into consideration in detail. Therefore, the current blade life model is not accurate enough to represent the actual situation. In this paper, the typical gas path deterioration are characterized by blade profile parameters，including the increment of the blade leading edge thickness, the increment of the blade trailing edge, and the change of the blade surface roughness in the whole operation life cycle model of blades. The influencing factors of aerodynamics and vibration are synthetically characterized through the study of their multi-disciplinary influence mechanism. And the relationship between the corresponding influencing factors and the variation of blade profile parameters is established. Thus the numerical simulation model under multi-physics is built to reveal its distribution and trends of the flow field and stress in the gas path. Finally, an accurate whole operation life cycle model of blades has been established based on the mentioned work. Its feasibility and accuracy has been verified by the operating data. And the result shows that it can protect the blades, ensure safe and stable operation, and reduce the deterioration rate.

运行时间累加会导致燃机叶片出现衰退，具体表现为结垢、腐蚀、损坏和顶端间隙等。作为燃机的基本部件，叶片的健康状况直接影响设备的效率和使用寿命。从安装到报废的过程是叶片的全生命周期，建立叶片全运行周期寿命模型，对深入研究叶片衰退机理，进一步优化设计和维护方案具有重要意义。目前寿命模型的建立未考虑多物理场因素以及不确定性的影响，存在准确性不足的问题。另一方面对衰退机理的研究局限于单学科，缺乏从多学科影响角度进行深刻剖析，同时也未考虑到叶片衰退过程中型线、粗糙度的变化。此外，现有模型没有建立工况和叶片参数与寿命影响因子的完整映射关系，泛用性不强。本项目拟应用多物理场耦合方法和不确定性方法，结合机器学习技术，建立更准确的叶片全运行周期寿命模型，从气动和振动等多学科视角，全面分析衰退机理，并通过实验验证模型准确性，为基于全运行周期寿命模型的叶片优化设计与运行维护提供理论和实验基础。

运行时间累加会导致燃气轮机叶片出现衰退，具体表现为结垢、侵蚀和腐蚀等。从安装到报废的全生命周期中，叶片尤其是高温叶片的健康状况直接影响燃气轮机的运行安全和使用寿命。目前的寿命评估未考虑多物理场因素及不确定性的影响，存在准确性不足的问题。对衰退机理的研究局限于单学科，缺乏从多学科影响角度进行深刻剖析，同时也未考虑到叶片衰退过程中型线、粗糙度的变化。此外，现有模型没有建立工况和叶片参数与寿命影响因子的完整映射关系，泛用性不强。据此，本项目基于多物理场耦合建模方法和不确定性分析方法，通过理论推导、数值分析、实验研究和机器学习方法，建立更准确的叶片全运行周期寿命模型并加以验证，从多学科影响的视角全面分析燃气轮机叶片的性能衰退机理，为基于全运行周期寿命模型的叶片运行维护与健康管理提供理论和实验基础。实际完成的三块研究内容，包括多物理场下高温叶片建模方法、燃气轮机性能衰退叶片多学科影响机理和高温叶片全运行周期寿命模型建立研究，为实现燃气轮机高温叶片的全运行周期寿命评估的实际应用研究提供了技术支撑。综上，本项目在研究过程中取得了如下研究结果。深入分析了高温叶片气动性能和寿命评估的多学科影响，建立了燃气轮机全运行周期下的性能衰退及故障影响知识库；利用逆向建模技术和3D打印技术，重构并加工了某高压涡轮的健康叶片和故障叶片，搭建了涡轮叶片平面叶栅实验台架，并基于该台架开展了叶型变化对多物理场的影响实验研究；搭建了考虑多物理场影响的高温叶片数值仿真模型，结合不确定性量化方法深入研究了高温叶片的服役损伤规律；基于探明的性能衰退叶片多学科影响机理，提出了基于疲劳蠕变交互的寿命评估方法，搭建了多物理场下燃气轮机高温叶片全运行周期寿命模型。相关研究结果为寿命评估提供了高效、精准和快速的技术方式，保证了燃气轮机运行的安全性和可靠性，为燃气轮机热端部件健康管理系统的研究奠定了理论基础。