微通道换热器在湿工况下的性能研究
Performance of micro-channel heat exchangers under wet condition
摘要：
对微通道换热器在湿工况下的换热性能和百叶窗翅片间冷凝水的排除进行了试验研究，分析了不同风速下微通道蒸发器的性能差异及结露对换热性能的影响。结果表明:换热量随着风速的增大而增大，扁管越宽换热量越大，但随着扁管宽度增大换热量增大的优势逐渐减弱；制冷剂分液是微通道蒸发器设计的关键，对蒸发器的传热与流动性具有很大的影响，且对安装角度较敏感；蒸发器空气侧翅片间的冷凝水难排除是影响蒸发器性能的主要原因，均匀的制冷剂分配对冷凝水的排水更有益。
Abstract：
The experimental research on the heat transfer performance and condensate drainage between louver fins of micro-channel heat exchangers under the wet condition is carried out. The performance difference of micro-channel evaporators at different air speeds and the influence of condensation on heat transfer performance are analysed. The results show that the heat transfer increases with the increase of air speed, and the wider the flat tube is, the larger the heat transfer is. However, with the increase of the tube width, the advantage of increasing heat transfer capacity is gradually weakened. The refrigerant liquid distribution is the key to the design of the micro-channel evaporator and has a great influence on the heat transfer and fluidity of the evaporator, and it is sensitive to the installation angle. The difficult discharge of condensate between the air side fins of the evaporator is the main reason affecting the performance of the evaporator, and the uniform refrigerant distribution is more beneficial to the condensate drainage.
Keywords:micro-channel; heat exchanger; wet condition; heat transfer; evaporator; condensate drainage; refrigerant