[关键词]
[摘要]
为了解翅片间距、翅片厚度、翅片材料和基管材料对直条缝翅片管换热器的传热和流阻性能的影响,以及获得通用的换热与流动阻力计算关联式,对一种直条缝翅片管换热器进行了实验研究。通过风洞试验台共进行了7个试件的试验,试验过程中管内水的进口温度和速度保持60 ℃和1.5 m/s不变,进风温度保持21 ℃,入口风速为1.5~4.5 m/s。结果表明:在管外空气侧雷诺数Rea为2647~8143范围内,随着翅片间距的增大,对流换热系数先增大后减小,存在一个峰值;翅片间距对阻力的影响与管外空气侧雷诺数有关,当Rea≤5 000时翅片间距越小摩擦系数越大,当Rea>5 000时,翅片间距越小,摩擦系数越小;翅片厚度的增加会增加对流换热系数和摩擦系数;紫铜(T2)翅片的对流换热系数高于8011铝合金(AL8011)翅片,但摩擦系数较低;T2基管的对流换热系数最高,铁白铜(B10)基管次之,316L不锈钢(316L)基管最低;不同的基管材料对摩擦系数没有影响。
[Key word]
[Abstract]
In order to understand the effects of fin pitch,fin thickness,fin material and base tube material on the heat transfer and flow resistance performance of straight slotted finandtube heat exchanger,and obtain the general calculation correlation of heat transfer and flow resistance,an experimental study on the straight slotted finandtube heat exchanger was carried out.A total of 7 samples were tested on the wind tunnel test bench.During the experiment,the inlet temperature and velocity of water in the tube remained unchanged at 60 ℃ and 1.5 m/s,the inlet air temperature remained at 21 ℃,and the inlet air velocity was between 1.5 m/s and 4.5 m/s.The results show that when the Reynolds number on the air side outside the tube Re a is 2 647 to 8 143,the convective heat transfer coefficient increases first and then decreases with the increase of fin pitch,and there is a peak value; the effect of fin pitch on the resistance is associated with the value of Reynolds number on the air side outside the tube,when Re a is no more than 5 000, the smaller the fin pitch is ,the greater the friction factor is; when Re a is more than 5 000,the smaller the fin pitch is,the smaller the friction factor is; the increase of fin thickness will increase the convective heat transfer coefficient and friction factor; the convective heat transfer coefficient of red copper (T2) fin is higher than that of aluminum alloy 8011 (AL8011) fin,but the friction factor is lower; T2 base tube has the highest convective heat transfer coefficient,followed by BFe10-1-1 iron white copper (B10) base tube,and 316L stainless steel (316L) base tube;different base tube materials have no effect on the friction factor.
[中图分类号]
TK172
[基金项目]