REFRIGERANT DISTRIBUTION IN MICORCHANNEL EVAPORATORS
In order to provide information on essential design of microchannel evaporators, an experimental study was conducted on the effects of geometry and of operating conditions on the distribution of the refrigerant in microchannel heat exchanger flowing in upward direction. The experimental results show that for all of the test conditions, both non-uniform distribution of the liquid and vapor phase mass flow rate and non-uniform distribution of the inlet and outlet vapor quality were found. The refrigerant distribution is strongly affected by the location, the inlet mass flux, and the inlet vapor quality of the manifold inlet. For the end inlet design, the profile of the branch tube inlet vapor quality is in a “stepwise shape. There exists two constant value regions, one of about 100％ vapor quality and another of about 10～20％ vapor quality with a very short transition region. For the side inlet design, the incoming refrigerant impinges on the manifold wall and is divided symmetrically near the inlet, the branch tube inlet vapor quality is about 70％ near the inlet, and the branch tube inlet vapor quality is about 20％ near the end of the manifold. Between the two regions, the branch tube inlet vapor quality decreases monotonously along the manifold. Conclusively, the side inlet refrigerant supply is preferred to the end inlet since the liquid refrigerant is distributed along more number of tube groups.
Yunho HWANG Dae-Hyun JIN Reinhard RADERMACHER
Center for Environmental Energy Engineering, University of Maryland 3163 Glenn Martin Hall Building, College Park, Maryland 20742, USA
国际会议
The 22nd International Congress of Refrigeration(第22届国际制冷大会)
北京
英文
2007-08-21（万方平台首次上网日期，不代表论文的发表时间）