采用折叠扁管与挤压扁管的微通道换热器长效特性

摘要

对采用折叠扁管与传统挤压扁管的微通道换热器长效特性进行了对比研究.分别进行了标准盐雾腐蚀实验,对比腐蚀前后两个换热器样品的换热量、空气侧压降和总热阻变化情况,结果表明,折叠扁管的样品在腐蚀后的各项性能均优于挤压管的样品.传统挤压扁管样件的翅片与扁管连接处率先被腐蚀破坏,14d腐蚀后就可观察明显的翅片脱落现象,且在28 d腐蚀后挤压扁管上出现泄漏；折叠扁管样件则是翅片率先被腐蚀,而翅片与扁管的连接处没有明显损坏,在49 d腐蚀后折叠扁管没有出现泄漏现象.这是由于折叠扁管能方便地配备保护层,实现牺牲翅片保护扁管的方法,在腐蚀过程中能有效地保护更为重要的扁管.折叠扁管的长效特性优于传统挤压扁管.%Corrosion is one of the main characters of A1 microchannel heat exchanger.In the present study,standard seawater acidified test (SWAAT) was carried out in microchannel heat exchangers with folded tube and traditional extruded tube,then the performance test and electron metallography analysis were carried on the test samples before and after the corrosion.The result showed that the performance of the sample with folded tube was much better than that with traditional extruded tube after SWAAT.According to the electron metallography analysis,for the test sample with extruded tube,the connection of fins and tubes was damaged first in the SWAAT.Obvious fin debonding occurred after 14 d of SWAAT,and leakage happened on the tube at main body after 28 d of SWAAT.In contrast,the fins of the test sample with folded tube were damaged first in the SWAAT,and no any fin debonding or leakage on the tube occurred after 49 d of SWAAT.The long-term performance of folded tube is better than that of extruded tube.