翅片结构对翅片管换热器积灰与压降影响的实验研究

积灰对具有不同翅片结构的翅片管换热器均会造成长效性能的衰减。本文搭建了换热器积灰可视化实验台,研究了翅片结构对积灰量及积灰后空气侧压降的影响。测试样件的翅片类型包括平直翅片、波纹翅片和开窗翅片;翅片间距范围为1.3~1.8 mm。实验结果表明:开窗翅片管换热器表面最容易沉积粉尘并增大积灰后压降,与平直翅片相比,波纹翅片和开窗翅片表面粉尘沉积量分别提高了25.6%和52.8%、积灰后压降增量分别提高了44.4%和165.6%;对于开窗翅片,小翅片间距有利于积灰并增大积灰后压降,与翅片间距1.8 mm的样件相比,翅片间距1.5 mm和1.3 mm的样件表面粉尘沉积量分别提高了26.2%和43.2%、积灰后压降增量分别提高了24.1%和49.4%;在积灰过程中,随着粉尘沉积量的增加,翅片管换热器空气侧压降先增大后保持稳定。

Experimental Investigation on Influence of Fin Structures on Particle Deposition and Pressure Drop of Fin-and-tube Heat Exchangers

The long-term performance of fin-and-tube heat exchangers with different fin structures will decay when covered with dust particles. In this paper, a visual experimental rig was established to investigate the effects of fin structures on particle deposition and air-side pressure drop. The fin types of test samples covered plain fins, wavy fins and louver fins, and the fin pitches ranged from 1.3 mm to 1.8 mm. The results show that, louver fins are most beneficial to particle deposition; the maximum particle deposition weight on wavy fins and louver fins increased by 25.6% and 52.8% respectively compared with that on plain fins, meanwhile the increment of pressure drop increased by 44.4% and 165.6% respectively. Small fin pitch can promote particle deposition and increase pressure drop; the maximum particle deposition weight on louver fins with fin pitch of 1.5 mm and 1.3 mm increased by 26.2% and 43.2% respectively compared with that on louver fin with fin pitch of 1.8 mm, meanwhile the increment of pressure drop increased by 24.1% and 49.4% respectively. The air-side pressure drop firstly increased then tended to be stable with the increase of particle deposition weight.