圆孔翅片管换热器的传热与压降特性  

Heat Transfer and Pressure Drop Characteristics of Circular Hole Finned-tube Heat Exchangers

作　　者：朱荣鑫[1,2] 王厚华[1] 王清勤[2] 吴伟伟 李国柱[2] 刘茂林[2] ZHU Rongxin;WANG Houhua;WANG Qingqin;WU Weiwei;LI Guozhu;LIU Maolin

机构地区：[1]重庆大学城市建设与环境工程学院,重庆400045 [2]中国建筑科学研究院,北京100013

出　　处：《煤气与热力》2017年第11期24-31,共8页Gas & Heat

基　　金：国家重点研发计划(2016YFE0133300);英国皇家工程院中英校企合作项目(UK-CIAPP\415);建筑安全与环境国家重点实验室开放基金资助项目(BSBE2016-07)

摘　　要：采用Fluent软件,对翅片管换热器中单翅片的传热(以翅片表面努塞尔数表征)与压降(以摩擦因子表征)特性进行模拟研究,对开圆孔翅片的传热强化效果进行评价。基于正交实验设计思路,以孔径和圆孔与基管位置为变量,设计了9组圆孔翅片,比较了平翅片(翅片表面未开圆孔的翅片)与9组圆孔翅片的表面努塞尔数、摩擦因子,筛选出传热强化效果最好的圆孔翅片。为揭示圆孔翅片强化传热的机理,根据Fluent软件模拟结果,对平翅片、圆孔翅片(传热强化效果最好的圆孔翅片)表面的温度场以及翅片横截面处翅片温度场及翅片表面空气温度场、速度场进行模拟分析。在空气雷诺数为480、960、1 440、1 920时,9组圆孔翅片的翅片表面努塞尔数比平翅片分别提高4%~12%、6%~21%、7%~23%、8%~24%,且所有翅片的摩擦因子相差不超过10%,说明平翅片表面开圆孔实现了传热强化,与圆孔位置相比,孔径对传热效果的改善影响更大。翅片表面的圆孔可有效阻碍其表面温度边界层、速度边界层的发展,增强气流扰动,有效强化翅片传热性能。The heat transfer of single fins in finned-tube heat exchangers （characterized by Nusselt number on the fin surface ） and the pressure drop （characterized by friction factor） are simulated and re- searched by Fluent software. The heat transfer en- hancement effect of the opening circular hole fins is e- valuated. Based on the orthogonal experimental design idea, taking the aperture and the positions of circular hole and the base pipe as variables, 9 groups of circu- lar hole fins are designed, the Nusselt number and fric- tion factor of flat fin without circular hole on the fin surface and 9 groups of circular hole fins are com- pared, and the circular hole fin with the best heat transfer enhancement effect is screened out. To reveal the mechanism of heat transfer enhancement of circular hole fins, the surface temperature field of flat fin and the circular hole fin with the best heat transfer en- hancement effect as well as the fin temperature field at the fins cross section and the air temperature field and velocity field on the fin surface are simulated and ana- lyzed according the simulation results using Fluent soft- ware. When the air Reynolds numbers are 480, 960, 1 440 and 1 920, the Nusseh numbers on the surface of 9 groups of circular hole fins are respectively 4% to 12%, 6% to 21%, 7% to 23% and 8% to 24% higher than that of the flat fin, and the difference in friction factor of all the fins does not exceed 10%, in- dicating that the heat transfer enhancement is realized by opening circular hole on the flat fin surface, and the aperture has a greater effect on the improvement of the heat transfer effect compared with the circular hole po- sition. The circular hole on the fin surface can effec- tively hinder the development of surface temperature boundary layer and velocity boundary layer and en- hance the airflow disturbance and the fin heat transfer performance.

关 键 词：翅片管换热器 开圆孔 传热强化 压降特性 数值模拟 

分 类 号：TU831.7[建筑科学—供热、供燃气、通风及空调工程]