核电汽轮机高压级内非定常流动对自发凝结的影响

The Effect of Unsteady Flow on Spontaneous Condensation in High Pressure Stage of Nuclear Power Turbine

为研究核电汽轮机高压级内非定常流动对湿蒸汽凝结流动液滴直径、压力以及湿汽损失等参数分布的影响,采用湿蒸汽非平衡凝结相变模型,对定常与非定常流动状态下湿蒸汽自发凝结流动进行三维数值分析。结果表明:非定常凝结流动趋于稳定时,各项参数的分布呈现周期性变化规律。非定常流动的动静干涉现象导致周向流场具有非均匀性,湿蒸汽级内的轴端功率下降0.266%。非定常流动过程中的静叶尾迹现象致使下游动叶通道内自发凝结的液滴直径减小。非定常凝结流动的压力位势作用使得动叶出口平均压力提高。非定常流动引起湿蒸汽凝结的热力学损失与制动损失分别升高62.27%和1.88%,疏水损失降低0.233%。

In order to research the influence of unsteady flow in the high pressure stage of nuclear steam turbine on the distribution of droplet diameter, pressure and wet steam loss of wet steam condensation flow, three dimensional numerical analysis is employed in spontaneous condensation flow of wet steam in steady and unsteady flow conditions by non- equilibrium condensation phase transition model of wet steam. The calculation results show that the distribution of the parameters of the unsteady condensing flow is periodic, when the unsteady condensing flow tends stable. The rotor-stator interaction phenomenon of unsteady flow results in the non-uniformity of the circumferential flow field, and the output power in the stage of wet steam decreases 0. 266%. Spontaneous condensation droplet diameter is decreased by stator wake phenomenon of unsteady flow in the process of the downstream rotor passage. The average pressure at outlet of rotor is increased by the effect of pressure potential of unsteady condensation flow. The thermodynamic loss and brake loss caused by unsteady flow are increased by 62.27% and 1.88%, respectively, and the loss is reduced by 0.233%.