涡轮叶片多层结构热障涂层隔热效果分析

为了获得叶栅流场作用下涡轮叶片热障涂层隔热性能,建立了带多层结构热障涂层的高压涡轮导叶模型,采用热流耦合方法计算热障涂层系统温度场,对叶片不同部位的涂层隔热效果,以及厚度和主流进口温度对隔热效果的影响进行研究。结果表明:涂层实际隔热效果在叶片吸力面最好,在尾部最差,在压力面沿顺流方向渐好。虽然涂层表面温度不同,但涂层内部的温降幅度与涂层表面温度的相关性不大,在吸力面涂层内部的温度降幅斜率最大,在尾部最小。隔热面层厚度每增加0.1 mm使合金平均温度约降低30℃。涂层隔热效果对主流进口温度较敏感,主流进口温度的变化与基底合金温降指标变化呈线性关系。

Analyzing of Thermal Insulation of Thermal Barrier Coatings of a Turbine Vane

In order to obtain the insulation properties of the turbine vane thermal barrier coating at the vane flow field. A model of a turbine vane with Thermal Barrier Coatings (TBCs) was built on. The thermal insulation of TBCs as well as the impacts of Top Coating (TC) thickness and inlet gas temperature was studied by the conjugate heat transfer method. It was found that the TBCs insulation effects achieved the maximum value at the suction side of the vane and the minimum value at the tail. And along the flow direction, the insulation effects increased gradually. Although the surface temperature of TC was variable, the temperature decline along TBCs thickness was independent on the surface temperature, and the temperature decline ratio got the maximum value at the suction side and the minimum value at the tail. Every 0.1mm thickening of TC can get about 30℃ drop of the average temperature of substrate alloy. Additionally the thermal insulation of TBCs was sensitive to the inlet temperature of gas, and it exhibited linear relationship versus the indexes of temperature decline of the substrate alloy.