超超临界汽轮机汽封漏汽流动特性的数值模拟研究

The research of numerical simulation for steam vapor seal leakage

利用ANSYS软件对梳齿型、侧齿型和蜂窝型汽封的内部气体流动特性进行数值模拟分析,其结果表明:在相同的特征尺寸和边界条件下,梳齿型汽封出口压力最高,蜂窝型汽封出口压力最低。在梳齿型汽封中,气流在汽封齿与凸台之间形成的蒸汽室内将产生漩涡;侧齿汽封由于增加了侧齿,产生的漩涡强度将增大;蜂窝汽封在每个小蜂窝中将产生漩涡,漩涡强度最小,节流效果最明显。蜂窝式汽封的漏汽量最小,梳齿型汽封漏汽量最大。当出口压力相同、入口压力不同时,随着入口压力的增加,3种汽封的漏汽量也随之增加;当出、入口压力相同时,随着汽封段长度的增加,3种汽封的漏汽量均减小。

The numerical simulation of internal vapor flow characteristics of the comb-type steam seal, side tooth steam vapor seal and honeycomb seal with ANSYS software shows that the outlet pressure of comb-type seal is the highest while the pressure of honeycomb seal outlet is the lowest under the same feature size, the same boundary con- ditions. In the comb type seal, airflow formed vortex in the steam room between the gland tooth and the convex plat- form. Due to the added lateral teeth, the vortex intensity in the lateral teeth gland is increased. For the honeycomb seal, the throttling effect is obvious each because each small cellular produces spiral. It can thus be seen that the steam leak- age from the cellular steam seal is minimum while that from comb-type steam seal is the largest. With the increasing steam inlet pressure, the steam leakage of all three seals increases under same outlet pressure and different inlet pres- sure. And with the increasing steam seal length, the steam leakage of all three seals decreases under same outlet and in- let pressure.