Exergy analysis and exergoeconomic evaluation of renewable energy conversion systems

Abstract

The present thesis deals with the Exergy Analysis and Exergoeconomic Evaluation of Renewable Energy Conversion Systems . This aspect is desirable to understand the deviation of actual performance from the ideal performance for different renewable energy conversion systems. Firstly, the concept of exergy analysis has been applied to evacuated tube collector based solar heating devices viz. solar air heater and solar water heater to investigate the performance of these systems. Solar air heater has been studied with and without thermal energy storage material viz. paraffin wax and hytherm oil. It is found that the both the efficiencies in case of heat storage material/fluid are much higher than that of without thermal energy storage, besides both the efficiencies in case of paraffin wax are slightly higher than that of hytherm oil case. As the mass flow rate increases peak of both efficiencies slightly shifts towards origin in case without storage material/fluid. However, in case with thermal energy storage, there is a small shift in the peak due to due to different mass flow rate of the working fluid except in case of 40LPM which is because of shift in the peak of solar radiation during that particular day. Further, the evacuated tube collector based solar air heater was modified into direct flow solar water heating system and thermal performance evaluation of the modified system was carried out using energy and exergy analyses under a typical weather condition in North India. The experiments have been carried out for different volume flow rates of water viz. 10, 15, 20, 25 and 30 litres per hour (LPH).