摘要
一些风冷式换热器的肋片或电子元器件上的散热片，它们以一定预紧力缠绕或镶嵌在管的外表面．当安装不好或由于热应力作用使预紧力消失，肋片与管表面接触热阻会明显增大．文中通过对环形肋片的稳态换热分析，研究了肋基存在接触热阻时对肋片换热的影响．理论分析和计算表明，接触热阻的存在对环肋的散热有明显的不良影响，且对小尺寸肋片散热的影响更加明显．当接触热阻增大到１０－３（ｍ２·°Ｃ）／Ｗ的量级时，可使散热减小５０％以上．因此，对镶嵌或安装在管外的肋片，应选形成接触热阻小的金属，并应使表面尽量光滑．肋片一定要以较大预紧力安装在肋管上，保证接触热阻小于１０－４（ｍ２·°Ｃ）／Ｗ．
The effect of contact thermal resistance on the steady heat transfer in radial fins of rectangular profile was studied. The results of theoretical analysis and computation show that the contact resistance has bad influence on the heat transfer in fins and the worse on that of small size. The heat flow rate can be reduced by 50% or more when the contact resistance increases to the magnitude of 10 -3 (m 2·°C)/W . Hence, it is concluded that the material used to make fins should form the less contact resistance. The out surface of pipe assembling the fins should be smooth and the pressure between the fins and pipe should be large enough to reduce the contact resistance to 10 -4 (m 2·°C)/W or less.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
1999年第8期990-992,共3页
Journal of Shanghai Jiaotong University
关键词
接触热阻
肋片
稳定传热
导热率
换热器
thermal contact resistance
fins
steady heat transfer
thermal conductivity
heat exchangers
