1000MW直接空冷机组散热单元换热特性的数值模拟  

Numerical Simulation on Heat-transfer Characteristics of Radiator in 1 000 MW Direct Air-cooling Units

作　　者：韩中合[1] 马务[1] 王智[1] 

机构地区：[1]华北电力大学能源动力与机械工程学院,保定071003

出　　处：《动力工程学报》2013年第5期358-363,共6页Journal of Chinese Society of Power Engineering

摘　　要：以某1 000MW直接空冷机组为例,对机组散热器外部流场进行了数值模拟,分析了不同迎面风速、环境温度、翅片间距以及翅片厚度对散热器外部换热和流动特性的影响.结果表明:随着迎面风速的增大,散热器外部的传热系数和流动阻力均显著增大,环境温度对散热器外部换热和流动特性的影响并不明显,但对总散热量影响较大;较大的翅片间距能增大散热器外部的传热系数、减小流动阻力,但会使单位管长的换热面积减小,总散热量减小;对应于一定的迎面风速,存在较为合理的翅片间距和翅片厚度,迎面风速越大,合理的翅片间距越大,翅片厚度越小.Taking the 1 000 MW direct air-cooling unit as an example, numerical simulation was carried out on external flow field of its radiator, so as to analyze the influence of following factors on external heat- transfer and flow characteristics of the radiator, such as the head-on wind velocity, ambient temperature, fin spacing and fin thickness, etc. Results show that with the rise of head-on wind velocity, both the ex- ternal heat-transfer coefficient and flow resistance increase significantly~ ambient temperature affects little on both the external heat-transfer coefficient and flow characteristics, but influences much on the total heat release. By enlarging the fin spacing, the external heat-transfer coefficient may be raised and the flow re- sistance may be reduced, however, this will lead to reduction of heat-transfer area per unit length of tube, resulting in decreased total heat release. For a fixed head-on wind velocity, there exists a reasonable fin spacing and fin thickness, which respectively increases and reduces with rising head-on wind velocity.

关 键 词：直接空冷机组 空冷散热器 传热系数 流动阻力 数值模拟 

分 类 号：TK247[动力工程及工程热物理—动力机械及工程]