排汽缸与末级叶片耦合流动的整周数值模拟  

Combined Numerical Simulation on Coupled Fluid Flow between Exhaust Hood and Last-stage Blades

作　　者：李勇[1] 

机构地区：[1]国网安徽省电力公司电力科学研究院,合肥230061

出　　处：《发电设备》2015年第5期311-315,共5页Power Equipment

摘　　要：使用CFD数值模拟软件CFX对某型号汽轮机的低压排汽缸和末级叶栅耦合流动进行整周数值计算。与单独计算排汽缸流场相比,排汽缸和末级叶栅耦合计算考虑了末级排汽对排汽缸内流场的影响。耦合计算的叶栅流道计算域可以采用单通道建模,也可以采用整周建模。与单通道叶栅建模相比,整周耦合计算能够减小周期性交界面引起的参数传递误差。因此,整周耦合计算能够模拟出更接近实际应用的排汽缸进口压力和速度分布,从而获得更加准确的排汽缸内流动情况,进一步提高排汽缸性能预估的准确度。A combined numerical simulation was conducted to coupled fluid flow between exhaust hood and last-stage blades of a steam turbine using CFD software CFX. Compared with single simulation of fluid flow in exhaust hood, the combined simulation takes consideration of the strong flow interactions between exhaust hood and last-stage blades. For modeling of the cascade flow passage in combined simulation, either single passage or whole annular cascade can be adopted, and the combined simulation based on whole annular cascade can reduce the error of parameter transmitting from one side to the other of periodic interface, which therefore is able to simulate actual inlet conditions and obtain accurate flow field in the exhaust hood, so as to improve the evaluation accuracy on aerodynamic performance of the exhaust hood.

关 键 词：汽轮机 低压排汽缸 末级叶栅 整周耦合计算 

分 类 号：TK262[动力工程及工程热物理—动力机械及工程]