Keywords: exergy analysis, chimneys, efficiency, heat pump, refrigeration, natural convection, forced convection, vapour compression, second law, thermodynamics
Exergy analysis of a vapour-compression refrigeration/heat pump cycle with chimney
The greatest speciality of this work is using chimneys with different heights above the condenser instead of a condenser's fan on the vapour-compression refrigeration/heat pump system chosen as an experimental set. Exergy analyses of natural convection with and without chimneys and forced convection on the same experimental set have been made with acceptances of steady state-steady flow system on each part of the set. Temperatures and pressures on each point of the system are measured and then specific enthalpies and entropies of them are determined. The coefficients of performance in refrigeration and heat pump modes and the exergies of each point, irreversibilities and second law efficiencies for each part of the system are calculated and given in tables comparatively. In this study, it is seen that the values for natural convection with chimney are between the forced convections and natural convections.