LAUSR

Abstract Operating packaged air conditioning systems at extremely high temperature ambient conditions result in severe performance degradation. In this paper, vapor injection (VI) with economization is proposed to improve system performance. An Environmental Control Unit (ECU) operating with R-407C has been retrofitted with an economized vapor injection (EVI) system and experimentally characterized in side-by-side psychrometric chambers. The performance of the EVI system for superheated and saturated injection conditions were compared to the case of without injection at different operating conditions. The results showed that the EVI system reduced the compressor discharge temperature by up to 5° C, and improved the cooling capacity and COP by up to 12.7% and 3.1%, respectively. The experimental data have been used to develop, tune, and validate a detailed steady-state cycle model. At last, the model has been employed to optimize the economizer geometry in order to maximize the system COP under such extreme weather conditions.