摘要
以水为工质,采用Fluent软件,对垂直放置的缩放管内插旋流片的自然对流换热进行了数值模拟分析,对光滑管、光滑管内插旋流片、缩放管和缩放管内插旋流片4种管道的传热情况进行对比,并将模拟值与实验值进行比较,两者的结果基本吻合。模拟结果表明,4种换热管中,缩放管内插旋流片水的传热系数最大,传热强化综合因子达到4以上;缩放管配合旋流片能加强壁面附近流体的扰动,又能使管内中心流体形成较强的漩涡流,加强壁面与管内中心流体的热量交换;减小速度场与温度场之间的夹角是增强传热性能的一个重要因素,缩放管内插旋流片的场协同角的体积平均值最小,因此缩放管内插旋流片的速度场和温度场协同程度更高,更有利于传热。
Natural convection heat transfer in a vertical converging-diverging（CD） tube equipped with twisted-tapes using water as working fluid was investigated by numerical simulation with Fluent software. The heat transfer was compared with those in a smooth tube, a smooth tube equipped with twisted-tapes and a CD tube. The numerical simulation results were verified by experiments. The simulation results showed that the heat transfer coefficient of water in the CD tube equipped with twisted-tapes was the largest and its heat transfer efficiency index could reach more than 4. The CD tube equipped with twisted-tapes could strengthen the fluid disturbance near the wall and could generate a strong vortex flow in the tube center, which could strengthen the heat exchange between the wall and the fluid center. It was found that the reduction in the intersection angle between the velocity field and the temperature field was one of the major factors influencing the heat transfer. In the CD tube equipped with twisted-tapes, the average volume of the intersection angles was the smallest, so the synergy degree of the velocity field and the temperature field was high, which could enhance the heat transfer more effectively.
出处
《石油化工》
CAS
CSCD
北大核心
2013年第10期1117-1122,共6页
Petrochemical Technology
基金
广东省重大科技专项(2011A080804012)
关键词
自然对流
缩放管
旋流片
强化传热
数值模拟
natural convection
converging-diverging tube
twisted-tapes
heat transferenhancement
numerical simulation
