Performance assessment and thermodynamic analysis of a hybrid solar air conditioning system

Abstract

Solar hybrid air-conditioning systems that use thermal energy of solar radiation using evacuated tube solar collectors attached to it are commercially available in many markets. These systems are proposed to save energy by constant volume heating of the refrigerant vapour from compressor and thereby imparting additional pressure rise to sustain refrigeration effect even when the compressor is off in its on–off cycle. The energy saving achieved by the hybrid system compared to its conventional vapour compression counterpart is studied by a few researchers in recent times and is reported to be varying from 25% to as high as 40%. In this paper the actual energy saving potential of a selected solar hybrid air-conditioning system is measured through experimental study. Also, it is experimented whether the hybrid system can save energy in continuous operation of its compressor. The results showed that the selected system has average 1.3% energy saving in on– off mode of compressor operation and nil saving if the compressor is working continuously. Further, a modification to the system for better energy saving is suggested and its thermodynamic cycle is theoretically analysed. The results shows that over 30% energy saving can be achieved.