V形翅片管式换热器的数值模拟研究

发布时间：2018-02-28 13:17

  本文关键词： V 形翅片管换热器 气流分布 不均匀性分布　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：翅片管式换热器极大地提高了管式换热器的换热系数,因此广泛的应用于暖通空调和化工等领域。随着近年来对能源消耗要求的提高,制冷用翅片管式换热器性能的提升也成为空调制造企业面临的一个重大课题。本文首先对空气经过开缝翅片的流动与换热情况进行了数值模拟,然后针对一款美式风管机中使用的V形翅片管式换热器,利用基于计算流体力学CFD原理的Fluent软件中的多孔介质模型,模拟计算了美式风管机中使用的V形翅片管式换热器中空气流动的不均匀分布情况。数值计算分析结果显示,在一定的进风量情况下,换热器迎风面的风速70%的区域流速集中在0.5-2.0m/s,有一些区域的流速高达4.2m/s,风速分布差别比较明显,并且模型计算出来的压差为26.2Pa,与实验实测值的24.0Pa相差只有9.1%,表明该模型能够较准确的计算出V形翅片管式换热器空气侧风速的不均匀分布情况。在得到的气流分布情况的基础上,进一步分析气流不均匀分布对V形翅片管式换热器换热性能的影响。结合翅片管式换热器设计计算软件CoilDesigner软件,计算出换热器换热情况及制冷剂的出口状态,结果显示换热器上中下三个环路制冷剂出口的过热度分别为9.3℃、7.3℃和5.2℃,与实验测试值相差最大只有0.7℃,而且换热量的误差在0.5%以内,验证了计算结果的正确性。为后续合理安排管路布置,保证各个管路出口制冷剂状态能满足压缩机进口的要求提供了依据。通过模拟及对比分析,较准确的计算出了V形翅片管式换热器空气侧风速的不均匀分布情况。本文研究内容可以为翅片管式换热器的优化设计提供一种可行的新方法,对后续的实验研究及结构优化有一定的指导意义。
[Abstract]:Finned tube heat exchanger greatly improves the heat transfer coefficient of tube heat exchanger, so it is widely used in HVAC and chemical industry. The improvement of the performance of finned tube heat exchanger for refrigeration has also become a major issue for air conditioning manufacturers. In this paper, the flow and heat transfer of air through slit fin are numerically simulated. Then for a V-shaped finned tube heat exchanger used in an American-style air duct machine, the porous medium model in Fluent software based on the CFD principle of computational fluid dynamics is used. The non-uniform distribution of air flow in the V-shaped finned tube heat exchanger used in the American air duct machine is simulated and calculated. The regional velocity of 70% on the upwind side of the heat exchanger is concentrated at 0.5-2.0 m / s, and in some areas the velocity is as high as 4.2 m / s, and the distribution of the wind speed is quite distinct. The pressure difference calculated by the model is 26.2Pa, which is only 9.1 from the measured value of 24.0Pa, which shows that the model can accurately calculate the non-uniform distribution of wind velocity on the air side of V-shaped finned tube heat exchanger. On the basis of the situation, The influence of uneven distribution of air flow on the heat transfer performance of V-shaped finned tube heat exchanger is further analyzed. The heat transfer situation and refrigerant outlet state of the heat exchanger are calculated by using the software CoilDesigner for the design and calculation of finned tube heat exchanger. The results show that the superheat of the upper, middle and lower loop refrigerant outlet of the heat exchanger is 9.3 鈩，

本文编号：1547454