不同盐析颗粒在汽轮机级内的分布特性  

Distribution Characteristics of Different Salting-out Particles in the Steam Turbine Stage

作　　者：胡鹏飞[1] 吴雪菲 曹丽华[1] 郑博文 HU Peng-fei;WU Xue-fei;CAO Li-hua;ZHENG Bo-wen(School of Energy and Power Engineering, Northeast Electric Power University, Jilin 132012, China)

机构地区：[1]东北电力大学能源与动力工程学院,吉林132012

出　　处：《汽轮机技术》2018年第2期81-84,138,共5页Turbine Technology

基　　金：国家自然科学基金委员会资助项目(51376041);国家重点研发计划项目(2017YFB0902102)

摘　　要：为深入了解汽轮机级内不同盐析颗粒的微观行为,以某国产600MW机组的中压缸第二级为研究对象,应用计算流体力学与群体平衡模型耦合方法,对汽轮机级内不同盐析颗粒在流场中的分布进行数值模拟研究,获得了不同盐析颗粒的粒子数、颗粒粒径及颗粒体积分数的分布规律。模拟结果表明:不同盐颗粒的粒子数分布是不同的,在中压缸中NaOH和Na_2CO_3生长最为迅速,其次为NaCl和SiO_2,而Na_2SO_4的沉积速度与其它钠盐相比较小;不同种类盐沉积颗粒粒径的变化存在较大差异,Na_2SO_4与NaCl在静叶前缘点的粒径较小,沿着蒸汽流动方向,Fe_2O_3的粒径下降较为迅速,SiO_2、NaOH与Na_2CO_3的粒径下降较为一致,而沿叶高方向,静叶压力面的粒径小于吸力面,而动叶与之相反;钠盐颗粒的析出程度较高,并逐渐贴近叶片表面,且硅氧化物的体积分数远大于铁氧化物。To have a better understanding of microscopic behavior of salting-out particles in a steam turbine,the second stage of intermediate pressure cylinder in a domestically-made 600 MW steam turbine was employed as a research object.Different salting-out particle distributions in the flow field of the steam turbine stage were simulated using CFD-PBM method. The distribution laws of particle numbers,particle diameters,and particle volume fractions of different kinds of salting-out particles were obtained. The simulation results show that the particle number distributions are different with different kinds of salting-out particles. NaOH and Na2CO3 particles grow most rapidly in the intermediate pressure cylinder,followed by NaCl and SiO2 particles,while the deposition velocity of Na2SO4 particles on the blade of intermediate pressure cylinder is smaller compared with other sodium salts. The particle diameter variations are different largely with different kinds of salting-out particles. Na2SO4 and NaCl particles have smaller diameters at the leading edge of stator blade. Along the steam flow direction,particle diameters of Fe2O3 decline relatively rapidly,while particle diameters of SiO2,NaOH and Na2CO3 are comparatively consistent,and along the blade height direction,the particle diameters on the pressure side of stator blade are less than the suction side,and the situation on the rotor blade is opposite. The precipitations of sodium salt particle degrees are higher and these particles gradually close to the blade surface,and the particle volume fraction of silicon oxide is much larger than iron oxide.

关 键 词：汽轮机 群体平衡模型 盐析颗粒 数值模拟 

分 类 号：TK261[动力工程及工程热物理—动力机械及工程]