基于群体平衡的汽轮机动叶表面盐析颗粒分布特性  

Distribution characteristics of salting-out particles on the surface of steam rotor blade based on population balance model(PBM)

作　　者：胡鹏飞[1] 李勇[1] 曹丽华[1] 吴雪菲 

机构地区：[1]东北电力大学能源与动力工程学院,吉林吉林132012

出　　处：《化工进展》2018年第2期437-443,共7页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(51376041);国家重点研发计划(2017YFB0902102)项目

摘　　要：为深入了解汽轮机动叶内盐析颗粒的微观行为,本文以某超临界汽轮机高压级动叶为研究对象,应用计算流体力学与群体平衡模型耦合方法,对汽轮机动叶内盐析颗粒在流场中的分布进行数值模拟研究,获得了盐析颗粒在动叶内的粒径分布及不同负荷时叶片尾缘处盐析颗粒数量密度分布规律。模拟结果表明:在汽轮机动叶吸力面附近的盐析颗粒粒径较压力面附近盐析颗粒粒径小,且叶根处颗粒粒径小于叶顶处;动叶压力面的颗粒数量密度呈前缘点尾缘点处大、中间段小的分布规律,并且盐析颗粒在叶片上的数量密度分布最大值并不出现在组分数及粒径最大处,而是出现在平均粒径为110~150μm的盐析颗粒沉积位置处;当汽轮机30%负荷运行时,粒径40μm盐析颗粒的数量密度是其在汽轮机额定负荷运行时的1.5倍,而粒径140μm盐析颗粒的数量密度仅为汽轮机额定负荷运行时的80%。In order to get a better understanding of microscopic behavior of salting-out particles in a steam turbine,a high-pressure grade rotor blade was employed in a supercritical steam turbine as a research object and the distribution of salting-out particles in the flow field from a steam turbine rotor blade was simulated using CFD-PBM method. The diameter distribution of salting-out particles in a rotor blade and the number density distribution of salting-out particles in the tailed-edge area of rotor blade with different load situations were obtained. The simulation results showed that the salting-out particle diameter near the suction side was smaller than that near the pressure side in a steam turbine rotor blade,and the salting-out particle diameter at the blade bottom was smaller than that at the blade tip. The particle number density distribution law at the pressure side of rotor blade was presented that the particle number density was larger both at the leading edge and at the tailed-edge of rotor blade while the particle number density was smaller in the middle parts of rotor blade,and the maximum value of salting-out particle number density distribution did not appear in the position having the maximum component number and particle diameter in the rotor blade,but it appeared in the position where salting-out particles with the average diameter 110—150μm deposit. When steam turbine was under 30% load operation,the number density of salting-out particles with 40μm diameter was 1.5 times than the situation when steam turbine was under rated load operation,while the number density of salting-out particles with 140μm diameter was only 80% of the situation when steam turbine was under rated load operation.

关 键 词：汽轮机动叶 盐析颗粒 群体平衡模型 两相流 

分 类 号：TK26[动力工程及工程热物理—动力机械及工程]