流动参数对双级螺旋套管换热器传热性能的数值分析

Numerical analysis of flow parameters on heat transfer performance of two-stage helically coiled heat exchangers

中文关键词: 流动参数；热泵  螺旋管换热器  传热性能  努塞尔数

英文关键词: Flow parameters  Heat pump  Helical heat exchanger  Heat transfer performance  Nusselt number

中文摘要:

      高效热泵系统性能研究一直是热泵空调领域普遍关注的热点问题，针对设计开发的双级套管串联式热泵系统。采用3D有限容积法和可实现的k-ε模型，数值分析入口流体温度、流动速度对换热系数以及内外管努塞尔数的影响规律。结果表明，降低入口水温或者增加入口制冷剂温度能够提高整体传热性能，Nui随着水和制冷剂流率的增加有所增加，而Nuo随着水流率的增加而增加，但随着制冷剂流率则增加而减小，Nui 和Nuo都随着水温的减小或制冷剂温度的增大而增大。

英文摘要:

      Research on the performance of high-efficiency heat pump systems has always been a hot issue in the field of heat pump air conditioning. The two-stage casing series heat pump system is designed and developed. The 3D finite volume method and realizable k-ε turbulence model is considered to investigate the influence of inlet fluid temperature and flow rates of inner and outer tube on the overall heat transfer coefficient and inner and outer tube Nusselt number. The results show that decreasing inlet water temperature or increasing inlet refrigerant temperature can improve thermal performance. Nui increases with the increase of water and refrigerant flow rate. Nuo increases with the increase of water flow rate. However, decreases with the increase of refrigerant flow rate. Both Nui and Nuo increase with the decrease of water temperature or The increase in refrigerant temperature increases.