基于沉积附着模型与热障涂层耦合传热的燃气透平综合冷却特性的机理研究

The deposition from the fuel impurities and the dust particles in the air are often found on the high temperature components for gas turbines, which is a hot issue nowadays. The experimental platform based on film cooling will be built for the study. To improve the existing adhesion model for the film-cooled turbines, the particle movement characteristics and the deposition mechanism near the wall will be investigated by using the particle image velocimetry (PIV) and the infrared thermal imaging instrument (IR). Considering the effects of the particle deposition and conjugated heat transfer on the thermal barrier coatings, the calculation method of the integrated cooling effectiveness will be put forward. Combined with the experimental data, an optimal cooling structure is also to be obtained. In addition, the integrated cooling effectiveness will be analyzed by the deformation experiments of the thermal barrier coatings and numerical simulations of the horseshoe vortex in the channel and coriolis force in rotation. The reliability and applicability of the prediction method for the integrated cooling effectiveness will be studied further. The reasonable analysis near the wall under actual working conditions for gas turbines will be carried out. According to the study, understanding of the gas-solid two phase flow and conjugated heat transfer will be escalated, which will provide both theoretical and technical supports for predicting the temperature distribution on the blade surface accurately.

针对燃料杂质和空气中灰尘等颗粒常沉积于燃气涡轮高温部件表面的热点问题，搭建气膜冷却沉积实验平台，采用PIV、红外热像仪等研究手段来分析气膜冷却保护下透平近壁区的颗粒运动特性与沉积规律，完善现有沉积研究中所使用的附着模型。通过对沉积影响下的基于热障涂层壁面冷却效果的耦合传热分析，结合实验数据，提出同时考虑颗粒沉积与耦合传热的综合冷却效率计算方法，并尝试获得最优的冷却结构。此外，通过热障涂层形变实验、通道马蹄涡与旋转科氏力的数值模拟，研究三者对综合冷却效率的影响，进一步分析颗粒沉积和耦合传热下综合冷却效率预测方法的可靠性与适用性，从而实现对实际工作下燃气透平近壁区沉积状况的合理分析，深化对透平中气固两相流和耦合传热的机理认识，为工作叶片表面温度的准确预测提供理论与技术支持。

针对燃料杂质和空气中灰尘等颗粒常沉积于燃气涡轮高温部件表面的热点问题，搭建了平板气膜冷却沉积实验平台，采用了红外热像仪等研究手段来分析气膜冷却保护下透平近壁区的温度分布与颗粒沉积规律，完善现有沉积研究中所使用的附着模型。通过对沉积影响下的基于壁面冷却效果的耦合传热分析，结合实验数据，提出同时考虑颗粒沉积与耦合传热的分析方法，并尝试获得最优的冷却结构。.碰撞和沉积主要发生在叶片压力侧，随着进气角的增加，碰撞率和沉积率在叶片压力侧靠近尾缘的位置处逐渐减少，而在压力侧气膜孔附近的位置逐渐增加。说明增大进气角度会减少颗粒对尾缘的磨损程度。随着颗粒粒径的增大，冲击率明显大于沉积率。申请人不但提出了一套准确预测颗粒沉积的模型，而且提出了跨学科测试颗粒沉积的方法，设计了一种用于检测雾化石蜡颗粒沉积量的天线结构。当微颗粒沉积在微带天线表面时，微带天线的介电常数由于电容的减小而增大。利用仿真软件CST MWS 2015对天线尺寸和介质层厚度进行可变扫描，寻找合适的天线形状。通过比较两个电容的充放电时间，可以计算出检测天线的电容。最终根据实测粒沉积质量，拟合出了颗粒预测函数曲线。.相关研究可以用于分析燃料或气流中掺杂颗粒物对设备工作稳定性的影响。此外，研究成果可以用来预测高燃气轮机透平叶片的使用寿命，并可推广到烟气轮机和整体煤气化联合循环（IGCC）发电系统等领域。