穿孔型翅片几何结构对换热性能的影响

Refrigeration Performance Analysis of Fin-tube Heat Exchangers by Effect of Perforated Fin Geometry

采用正交试验与数值模拟相结合的方法,针对影响翅片管式制冷换热器翅片表面开孔的3个参数,孔型、开孔几何尺寸及开孔位置,确定了3种优化的穿孔翅片片型.以平翅片作为基础片型,分别将4种翅片用于管式制冷换热器.风洞试验表明,结霜工况下,1.5～5.2 m· s^-1的试验风速范围内,翅片表面开椭圆孔的翅片管式制冷换热器换热性能最好,其单位面积制冷量、翅片平均表面对流换热系数、压缩机能效比相对平翅片均有明显提高.以风速2.5m·s^-1为例,上述各值分别提高了37.8％,79.4％,25.0％.空气流过翅片管式换热器的平均阻力则降低了30.0％.

Three types of optimal perforated fin were chosen based on an analysis of orthogonal test and numerical simulation combination method, as the plain fin for based case, the four types of fin were employed on fin-tube heat exchangers. The optimization of fin perforated parameters including three factors： the hole shape, the hole geometry dimension and the location. By wind tunnel experiments, it was demonstrated that elliptic perforated fin-tube refrigerated heat exchangers had the best heat exchange ability with 1.5- 5.2 m· s^-1 air velocity under frosting conditions among the four types heat exchanger. When the air velocity was 2.5 m · s^-1, the results illustrated that SK-E-B type elliptic perforated fin tube exchangers could increase refrigeration capacity per unit area, average fin surface heat transfer coefficient, compressor＇s coefficient of performance by 37.8%, 79.4%, 25.0% respectively, while mean air flow resistance through the SK-E-B fin-tube decreased by 30.0%.