The refrigerant flow rate in the automotive air conditioning system decreases at low loads. The same holds for the corresponding refrigerant velocity at the inlet of the evaporators' headers. The performed numerical simulations clearly show that this decrease of the refrigerant two-phase flow velocity in the horizontal header leads to the formation of the liquid layer on the bottom of the header. The liquid layer feeds mainly the first downward connected evaporating channel, while the feeding of the remaining channels is negligible. This effect causes the evaporator exit air temperature stratification. In order to overcome this problem the installation of the fins over the inlet of evaporating channels is considered. The numerical simulations of refrigerant two-phase flow show that the new header design improves the uniformity of the liquid and vapour phase distribution from the header towards the evaporating channels. This leads to the reduction of the temperature stratification of air at the evaporator exit plane.
Refrigerant maldistribution in an evaporator of automotive air conditioning system: investigation and a design improvement by numerical simulations
2013
10 Seiten, 11 Bilder, 20 Quellen
Conference paper
English
Automotive Refrigerant System Induced Evaporator Hoot
SAE Technical Papers | 2005
|Automotive refrigerant system induced evaporator hoot
Automotive engineering | 2005
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