集约型AHU内椭圆管翅片换热器空气侧特性的数值模拟

Numerical Simulation of Air-Side Characteristic of Oval-tube Fin Heat Exchangers in Intensive AHU

针对位于集约型AHU内部的椭圆管翅片换热器,在合理简化模型的基础上,运用CFD方法对其进行数值模拟,并与同当量直径的圆管翅片换热器进行比较。研究分析了两种结构换热器综合性能的差异、空气侧速度与温度场的分布特征。结果表明:椭圆管换热器出口平均温度高,尾部的涡流与高温区域小,综合换热性能优于圆管,运用在AHU中能够减少阻力损失并增强换热,进而提高空调系统的整体效率。探讨了翅片间距、翅片厚度及管间距3种结构参数对椭圆管翅片换热器性能的影响,为椭圆管在AHU内的运用及优化设计提供参考。

For oval-tube fin heat exchangers in intensive AHU, CFD method was used for numerical simulation on the basis of reasonable model simplification, and the oval-tube fin heat exchanger was compared with circular-tube fin heat exchanger with the same equivalent diameter. This paper studied and analyzed the differences between two kinds of heat exchangers in terms of comprehensive performance, and the distribution feature of the air-side velocity and temperature field. The results show that the average temperature at the outlet of oval-tube heat exchanger is high; vortex and high temperature area at the tail is small; the comprehensive heat exchange performance is superior to circular-tube heat exchanger. The application of oval-tube heat exchanger in AHU can reduce the resistance losses and enhance the heat transfer. Furthermore, the oval-tube heat exchanger can improve the overall efficiency of air conditioning system. In addition, this paper discussed the effects of fin distance, fin thickness and tube distance on the performance of oval-tube fin heat exchanger, providing the reference for the application and design optimization of the oval tube in AHU.