火焰筒多斜孔冷却方式壁温梯度和冷却效率试验

针对高温升燃烧室以延长其火焰筒使用寿命为目的,实验研究了多斜孔冷却方式孔排列方式、壁厚与孔径比h/d以及无量纲参数PS/d2对主燃烧室采用多斜孔冷却方式的火焰筒壁温梯度和冷却效率的影响.实验中冷却气为常温常压,主流速度ug≈20 m/s,多斜孔内气流与主流速度比约为0.66,主流与冷却气温度比约为1.25.实验结果表明:长菱形多斜孔实验板比正菱形实验板壁温梯度小、冷却效率高;减小h/d或者增大PS/d2都可以降低壁温梯度,但同时冷却效率也会降低.

Experimental investigation of the temperature gradient and cooling efficiency for effusion wall cooling methods on combustion liner

Gas turbine combustor cooling has steadily acquired major importance whenever engine performances have to be improved.Effusion cooling is becoming one of the most efficient cooling techniques for protecting metal surfaces against hot gases in combustor liners.As one of the most important influential factors to combustor life-span,the temperature gradient of the effusion wall and the cooling efficiency were investigated experimentally under the guidance of similarity theory.Geometric parameters such as the patterns of holes arrangement and the ratio of the wall thickness to the hole diameter h/d,as well as PS/d2,were varied in four different test models.IR thermograph was used to perform local measurements of the surface temperature field.The experimental results indicated that it had a better performance in both the temperature gradient and the cooling efficiency if P/S=1 as compared with P/S=2;the temperature gradient would be reduced by decreasing h/d or increasing PS/d2,while the cooling efficiency would decline at the same time.