铝圆管换热器在VRF热泵室外机应用可行性分析

Feasibility analysis of aluminum tube heat exchanger in VRF heat pump outdoor unit

通过利用仿真模拟和实验测试两种手段对内螺纹铝圆管换热器在某家用多联机空调热泵机型4 HP室外机的可行性应用进行了研究。从换热性能和成本两方面考虑,来确定此类换热器替换原来内螺纹铜圆管换热器的设计原则和改善措施。模拟与测试结果表明:相同运行工况条件下,对于管径Φ7 mm铜管换热器,如使用同排数管径Φ7 mm铝圆管换热器进行直接替换(其他结构特征不做改动,如管间距、排间距、翅片间距、流路等),整机制冷能效平均降低了2.2%,制热能效平均降低了1.8%,但可通过增加换热面积,调整流路设计,改良胀管工艺、内螺纹齿形进行改善。

The feasibility of internally threaded Al round tube coil applied in 4HP outdoor unit(ODU)of in residential Variable Refrigerant Flow(VRF)heat pump was studied by simulation and test,which aims to establish a design methods and improvements for replacing internally threaded copper round tube heat exchanger based on the performance and cost.The simulation and test results show that under the same operating conditions,directly replacingΦ7 mm Cu tube coil byΦ7 mm Al tube coil with the same rows(keeping other structural not be changed,such as the tube spacing,row spacing,fi n spacing,flow paths,etc.),the cooling energy efficiency is reduced by 2.2%on average,and the heating energy efficiency is reduced by 1.8%on average,which can be improved by increasing its heat exchanger area,adjusting the flow path design,and improving its expansion tube process or modifying its internal thread profile.