Analysis of a solar-assisted ejector cooling system for air conditioning

Ejector refrigeration is one of the most promising technologies because of its relative simplicity and low initial cost. In this work, a theoretical study has been carried out to assess system and refrigeration efficiencies of a solar-assisted ejector cycle using water as the operating fluid. The model was based on a 1D ejector approach, including both the refrigeration and solar collector cycles. Ejector performance was evaluated for different operating conditions. The results indicated that in order to achieve an acceptable coefficient of performance, generator temperatures should not fall below 90°C. Evaporator temperatures below 10°C and condenser temperatures over 35°C resulted in a significant drop in system efficiency, and therefore these conditions can be identified as minimal (reference) design values. The required solar collector area to provide 5 kW of cooling power was calculated for different operating conditions. Ejector dimensions were also calculated using the constant pressure mixing ejector theory. Copyright The Author 2009. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org, Oxford University Press.