摘要
采用三维数值模拟方法,研究了麻面管的结构参数对流体流动和换热特性的影响,运用多元线性回归的方法,分别拟合出换热与阻力的准则关联式。结果表明:管内壁面的周期性凸包对近壁处边界层有较好的扰动作用,改善了流体速度场与温度场的协同性,实现了强化换热;相比于光管,麻面管的努塞尔数Nu增幅为16%～40%,摩擦阻力系数f增幅为15%～53%,综合换热性能指标C_(PEC)范围在1.05～2.5,与光管换热器相比,当换热量与流体功耗相同时,麻面管换热器的相对换热面积可减小10%～35%,当换热面积与流体功耗相同时,相对换热量可提高1.08～1.36倍,极大地提升了换热器的经济性。
The influence of structural parameters on the fluid flow and heat transfer characteristics in a pitted tube was studied using three-dimensional numerical simulation, while criterion formulae were fitted respectively for the heat transfer and resistance characteristics by multiple linear regression method. Results show that the periodic convex hull on the inner wall of tube has a good disturbance effect on the boundary layer near the wall, which improves the synergy between fluid velocity field and temperature field, thus enhancing the heat transfer effectiveness. Compared with smooth tubes, the Nusselt number(Nu) and friction resistance coefficient of a pitted tube could be respectively increased by 16%-40% and 15%-53%, while the comprehensive performance evaluation criterion(CPEC) lies in 1.05-2.5. Compared with smooth tube heat exchangers, the relative heat transfer area of a pitted tube heat exchanger could be reduced by 10%-35%, when the heat transfer and fluid power consumption remain unchanged;the relative heat exchange capacity could be improved by 1.08-1.36 times, when the volume of heat exchanger and the fluid power consumption keep constant, in which case, the economical efficiency of the heat exchanger could be improved significantly.
作者
闫顺林
于兴宝
韩建
曹保鑫
张莎
YAN Shunlin;YU Xingbao;HAN Jian;CAO Baoxin;ZHANG Sha(School of Energy,Power and Mechanical Engineering,North China Electric Power University,Baoding 071003,Hebei Province,China)
出处
《动力工程学报》
CAS
CSCD
北大核心
2019年第2期116-122,共7页
Journal of Chinese Society of Power Engineering
关键词
麻面管
涡流
数值模拟
性能评价
pitted tube
vortex
numerical simulation
performance evaluation
