超临界CO_(2)在不同肋管中颗粒物沉积特性  

Particle deposition characteristics of supercritical CO_(2)in different ribbed tubes

作　　者：毛赏 周涛 卢怀畅 刘文斌 Mao Shang;Zhou Tao;Lu Huaichang;Liu Wenbin(School of Energy and Environment,Southeast University,Nanjing 210096,China)

机构地区：[1]东南大学能源与环境学院,南京210096

出　　处：《东南大学学报（自然科学版）》2022年第6期1114-1121,共8页Journal of Southeast University：Natural Science Edition

基　　金：2021年江苏省“双创人才”资助项目(JSSCRC2021500);国家重点研发计划资助项目(2020YFB1901701-03)。

摘　　要：为了研究不同管道形状对超临界CO_(2)中颗粒物沉积的影响,构建了光滑管道、矩形肋管和半圆形肋管的几何模型.采用AKN k-ε模型预测超临界CO_(2)的流动特性,并基于离散相模型对流体内部的颗粒进行追踪.分析了流体速度2~6 m/s、入口温度290~330 K和颗粒直径1~10μm范围内颗粒物的沉积特性.结果表明,随着流速增加,小粒径(d_(p)<5μm)颗粒沉积效率保持恒定,大粒径(d_(p)≥5μm)颗粒沉积效率降低.在伪临界点以下,颗粒物的沉积速度不受流体温度的影响;在伪临界点以上,颗粒物的沉积速度随流体温度的增加而增加.由于肋管具有较大的湍流动能和二次流区域,因此肋管中颗粒沉积效率大于光滑管道.管道内布置矩形肋和半圆形肋都有助于颗粒物沉积,且矩形肋管沉积效率大于半圆形肋管.To study the effects of different tube shapes on the particle deposition in supercritical CO_(2),geometric models of smooth tube,rectangular ribbed tube and semicircular ribbed tube are established.The AKN k-εmodel is used to predict the flow characteristics of supercritical CO_(2) and the particles inside the fluid are traced based on the discrete particle model.The particle deposition characteristics in the range of fluid velocity from 2 m/s to 6 m/s,inlet temperature from 290 K to 330 K and particle diameter from 1μm to 10μm are analyzed.The results show that the deposition efficiency of small-size(d_(p)<5μm)particles remains stable and the deposition efficiency of large-size(d_(p)≥5μm)particles decreases with the increase of the flow velocity.Below the pseudo-critical point,the particle deposition velocity is not affected by the fluid temperature.Above the pseudo-critical point,the particle deposition velocity increases with the increase of the fluid temperature.Because of the large turbulent kinetic energy and secondary flow region in the ribbed tube,the particle deposition efficiency in the ribbed tube is larger than that in the smooth tube.Both rectangular and semicircular ribs are arranged in the tube to facilitate particle deposition,and the deposition efficiency of the rectangular ribbed tube is greater than that of the semicircular ribbed tube.

关 键 词：超临界CO_(2) 颗粒沉积 肋管 沉积效率 

分 类 号：TL333[核科学技术—核技术及应用]