汽轮机切向进气蜗壳气动性能研究

Investigation on the Aerodynamic Performance of the Steam Turbine Tangential Admission Volute

采用实验测量和数值模拟的方法,研究了单独切向进气蜗壳和切向进气蜗壳耦合静叶结构的气动性能和流场特性。实验测量了3种出口马赫数下的单独切向进气蜗壳和4种进出口压比下的切向进气蜗壳耦合静叶结构的总压损失系数、出口气流角、质量流量。采用数值求解三维RANS和SST湍流模型分析了实验测量的切向进气蜗壳的流场形态。数值模拟得到的气动参数值与实验值吻合良好,验证了数值方法的可靠性。结果表明:单独切向进气蜗壳与切向进气蜗壳耦合静叶结构的出口气流角的分布与大小基本上不随进气总压的增加而改变,出口气流角在152.0°左右,切向进气蜗壳耦合静叶结构的出口气流角在166.6°左右;与单独切向进气蜗壳相比,切向进气蜗壳耦合静叶结构的出口气流角沿周向的分布更为均匀;单独切向进气蜗壳和切向进气蜗壳耦合静叶结构的总压损失系数和质量流量随着进气总压的增加而增加,单独切向进气蜗壳的总压损失系数由0.73%增加到1.64%,切向进气蜗壳耦合静叶结构的总压损失系数由0.82%增加到2.66%。研究工作可为汽轮机切向进气蜗壳的设计和性能分析提供参考。

The aerodynamic performance and flow fields of the tangential admission volute and the admission volute coupled with downstream vanes were experimentally measured and numerically simulated in this research.The total pressure loss,outlet flow angle and mass flow rate of the tangential admission volute at three different outlet Mach numbers and of tangential admission volute coupled with downstream vanes at four different inlet total pressures were measured.The flow fields of the experimental tangential admission volute models were numerically investigated using three-dimensional Reynolds-averaged Navier-Stokes(RANS)equations and SST turbulence model.The simulated numerical aerodynamic parameters of the tangential admission volute were in good agreement with the experimental data and the accuracy of the presented numerical method was validated.Results showed that the outflow angles of the tangential admission volute and that of the tangential admission volute coupled with downstream vanes usually keep constant when the inlet total pressure is increased.The outflow angles of the tangential admission volute and of tangential admission volute coupled with downstream vanes are equal to 152.0°and 166.6°,respectively.Compared with the tangential admission volute,the circumferential outflow angle of the tangential admission volute coupled with downstream vanes distributes more uniformly.The total pressure loss and mass flow rate of the tangential admission volute and the tangential admission volute coupled with downstream vanes increase with the inlet total pressure.With the increase of inlet total pressure,the total pressure loss of the tangential admission volute increases from 0.73%to 1.64%;meanwhile,the total pressure loss of the tangential admission volute coupled with downstream vanes increases from 0.82%to 2.66%.This work provides a reference for the design and performance analysis of the tangential admission volute for steam turbines.