涡轮叶片冷却通道换热特性研究

Study of the Heat Exchange Characteristics of the Cooling Passages of a Turbine Blade

以某型新设计船用燃气轮机高压涡轮动叶拟备用的冷却流路方案为研究对象,采用全三维流热耦合方法研究了不同冷却通道形式对涡轮叶片换热的影响。比较了3种方案,方案Ⅰ的优点在于消除了叶片顶部凸台的高温区域,截面平均温度及冷却效果均可接受;方案Ⅱ充分利用冷气与金属温差叶片冷却效果与截面平均温度分布较好。方案Ⅲ强化了叶身中段换热。结果表明,通道形式对叶片表面的温度分布作用明显,同时也影响着叶片的冷却效果,以及截面平均温度沿叶高的分布。本研究成果为该涡轮叶片冷却流路的选用提供了理论依据。

With the cooling flow passage scheme prepared for the high pressure turbine blades of a marine gas turbine newly designed serving as the object of study,by adopting the full three-dimensional flow-heat coupling method studied was the influence of different cooling passage forms on the heat exchange in the blades of the turbine. A total of three schemes were compared. The merits of the Scheme I lie in its eliminating the high temperature zone on the top boss of the blade and making the average temperature in a section and cooling effectiveness acceptable. The Scheme II makes full use of the temperature difference between the cooling air and metallic surface and makes the cooling effectiveness to the blades and the average temperature distribution in a section to be relatively well. The Scheme III intensifies the heat exchange in the middle of the blades. It has been found that the passage form remarkably affects the temperature distribution on the surface of the blades and at the same time also influences the cooling effectiveness of the blades and the distribution of the average temperature along the blade height. The foregoing can offer a theoretical basis for choosing appropriate cooling passages of the turbine blades.