进气室作用下压缩空气储能轴流涡轮弯导叶流动特性

Flow Characteristics of Bowed Stator in a Compressed Air Energy Storage Axial Turbine Under the Effect of Intake Chamber

在压缩空气储能轴流涡轮中,紧凑型进气室常会形成三维不均匀流动结构并降低流场均匀性。为使下游导叶能够在上述流场不良影响下进一步减少流动损失,该文引入J型弯曲导叶,并采用三维计算流体动力学方法,对比研究进气室非均匀流场影响下,该结构内部流场结构、损失分布特点以及对轴流涡轮性能的提升效果。结果表明:J型弯曲导叶能够降低机匣和轮毂附近相邻叶片之间的压力梯度,减小端壁二次旋涡强度,并在全周范围内使10%、50%和90%叶高处的熵产值分别下降25.92%、42.10%、9.72%。在紧凑型进气室影响下,J型弯曲导叶仍使轴流涡轮的等熵效率和质量流量分别提高0.41%和1.59%。结果可为同类压缩空气储能轴流涡轮的优化设计提供参考。

In the axial turbine adopted in compressed air energy storage(CAES)system,the intake chamber with compact structure always form three-dimensional flow structure and reduce the uniformity of flow field.In order to make the downstream stator suppress the negative effects of the above flow field and reduce the flow loss,a J type bowed stator was adopted in this paper,and three-dimensional computational fluid dynamics(CFD)method was adopted to compare and investigate the effect of the bowed stator on internal flow field structure,loss distribution,and the performance improvement of the axial flow turbine under the influence of the non-uniform flow field of the intake chamber.The results illustrate that the J type bowed stator can decrease the pressure gradient between the adjacent blades near the casing and hub,suppress the secondary vortex intensity on the end wall,and reduce the entropy production at 10%,50%,90%of blade height by 25.92%,42.10%and 9.72%respectively along whole circumference direction.Under effects of the compact intake chamber,the J type bowed stator can still increase the isentropic efficiency and the mass flow rate of the axial turbine by 0.41%and 1.59%respectively.The results can provide a reference for the optimization design of similar axial-flow turbine in CAES system.