Abstract:

To understand the effect of fin structure on heat transfer and resistance, numerical simulation and validation experiments were performed on super slit finned tube heat exchangers with different fin pitches P_f and slit heights S_h. When R_e was less than 7200, heat transfer and resistance performance was improved with P_f increase. When R_e was greater than 7200, heat transfer was improved but resistance was declined with P_f decrease. In case of S_h increase, heat transfer declined first and enhanced later, whereas resistance showed an opposite trend. With regard to five super slit finned tube heat exchangers with different fin structures, the comprehensive flow and heat transfer performance were improved while the actual heat transfer area was decreased with P_f increase, which a consideration of all factors should be required. A good agreement was observed between the numerical simulation and experimental results when R_e was in the range of 2734-6712, indicating that the numerical simulation method could predict the heat transfer and resistance characteristics of super slit finned tube heat exchangers. These results would set a basis for optimization between structure and performance of these heat exchangers.

Key words: super slit finned tube heat exchangers, heat transfer, numerical simulation, modeling experiment, comprehensive flow and heat transfer performance, optimization

摘要：

为了获得翅片结构对双向开缝翅片管换热器传热与阻力性能的影响规律，对不同翅片间距P_f和开缝高度S_h的双向开缝翅片管换热器进行了数值模拟，并对数值模拟结果进行了模化试验验证。结果表明：当R_e<7200时，增大P_f会提高双向开缝翅片管换热器的传热与阻力性能；当R_e>7200时，减小P_f会提高其传热性能，降低其阻力性能；随着S_h的增加，双向开缝翅片管换热器的传热性能先降低后提高，阻力性能先提高后降低；对于不同翅片结构的5种双向开缝翅片管换热器，P_f越大，综合流动传热性能越高，但实际换热面积会减小，需综合考虑；在R_e=2734~6712范围内数值模拟与试验结果吻合较好，数值模拟能较准确地反映双向开缝翅片管换热器的传热与阻力特性。研究成果可为双向开缝翅片管换热器的结构与性能优化提供依据。

关键词: 双向开缝翅片管换热器, 传热, 数值模拟, 模化试验, 综合流动传热性能, 优化