核电汽轮机末级空心静叶抽吸除湿研究

采用粒子输运模型对某核电汽轮机低压缸末级空心静叶栅内的水滴运动轨迹和沉积分布进行三维数值计算,得出水滴沿静叶相对叶高和相对叶宽的沉积量,并讨论不同除湿槽几何参数对空心静叶抽吸除湿性能的影响.结果表明:水滴主要沉积在空心静叶压力面的上半部分,少量沉积在吸力面进口边和上端壁表面.压力面上的除湿槽应当在工艺许可的条件下尽量靠近出口边,吸力面上的除湿槽应尽量和压力面除湿槽开设在同一压力水平上；除湿槽宽度增大时并不一定有利于提高除湿效率,最佳宽度与汽流速度和抽吸压比有关；除湿槽角度应在工艺许可的条件下应尽量小一些.研究结果对后续的试验研究及工程设计具有指导意义.

Study on Wetness Extraction of Hollow Stationary Blade of Last Stage in Nuclear Turbines

With a particle transport model,3D numerical calculations are presented for pathway and deposition distribution of droplets in cascade of hollow stationary blade,which is located in the last stage of a nuclear turbine.The deposition quantity of droplets along the relative altitude and width of stationary blade is deduced,and the effects of different geometric parameters of grooves on the performance of wetness extraction are discussed.It indicates that the majority of droplets are deposited on the upper half of pressure side,and a small quantity of droplets are deposited on the leading edge of suction side and shroud.If the process technique is available,the grooves on pressure side should be close to the trailing edge as much as possible,and the local pressure of grooves on suction side should be on the same level with that on pressure side.The efficiency of wetness extraction shouldn’t be always improved when the grooves increase in width,and the optimum width is correlative to the velocity of steam flow and the pressure ratio of extraction.The angle of grooves should be small as much as possible.The research results have instructive significance to the following experimental study and engineering design.