汽轮机低压排汽缸内流场的数值模拟研究

Numerical Simulation of the Low-pressure Exhaust Hood of Steam Turbine

利用fluent软件对汽轮机低压排汽缸进行数值模拟,分析排汽缸内部流场特性、涡系分布;利用CFD-POST软件分析排汽缸内部气动性能参数及其分布,并与流场分布进行对比,获知其压力损失来源。研究结果表明:通道涡是造成排汽缸内部能量损失最主要的原因;分离涡分布虽然小于通道涡,但是其最主要的影响是造成扩压管扩压性能的下降;其它涡系结构分布远离主流,影响较小。为排汽缸的优化设计提供基础。

This paper use Fluent to take the numerical simulation for the exhaust hood. Analysis the internal flow field char- acteristics of the exhaust hood, and the distribution of the vortex; use CFD-POST to analyses the pneumatic parameters, and contrast with the flow field, get the origin of the pressure loss. The results show that the passage vortices are the major sources of energy loss; the range of separation vortices is smaller than passage vortices, but thier major influence is depressing the ability of pressure recovering; other vortices apart from mainstream, and their influence is weak. This paper provide foundation for the optimize design of the exhaust hood.