某汽轮机中的湿蒸汽流动研究

按照平衡凝结流动设计方法设计的低压汽轮机实际按照非平衡凝结流动规律运行，因此会带来额外的损失。为了评估两种凝结方式的差异，对某汽轮机低压缸内的平衡凝结和非平衡凝结流动进行了对比研究。结果表明：与平衡凝结流动相比，非平衡凝结流动中汽轮机低压缸各级透平焓降、反动度、湿度分布以及各叶栅表面压力分布、叶栅进口攻角、出口气流角、末级出口余速及低压缸内热力过程线均有明显差异。按照非平衡凝结流动规律设计低压汽轮机是进一步提高其效率的一个途径。

Study on the Wet Steam Flow in a Steam Turbine

Traditionally the low pressure （LP） cylinder of steam turbine is designed in accordance with the equilibrium condensation theory. However in a real steam turbine the non-equilibrium condensation is happened. As a result additional losses may be produced. The flows with equilibrium and non-equilibrium condensation in the LP cylinder of a steam turbine are simulated and compared. It is shown that compared with the equilibrium flow, the enthalpy drop, reaction and wetness in each turbine stage, the surface pressure, attack angle and exit flow angle of each blade row, as well as the leaving velocity of last stage and the thermal process in the non-equilibrium condensing flow are obviously changed. The result indicates that it＇s necessary to apply the non-equilibrium condensation theory to design the LP cylinder.