Exergy and Exergo-Economic Analysis of Organic Rankine Cycle Driven by Solar Energy and by Using the PCM in Storage Tank

Organic Rankine Cycles are appropriate technology for the conversion of low-quality thermal energy to electrical power. In this research, the organic Rankine cycle driven by an evacuated tube collector was studied from energy, exergy, and exergo-economic points of view. Then, various cases such as the temperature and pressure input to the turbine, the temperature difference of the evaporator of the organic cycle, and the solar flux were evaluated. Simulation results show that power energy and exergy efficiency are 45.2 and 9.7 and the amount of work output and total irreversibility are 51.5 and 1291.8, respectively. The solar collector and the storage tank are the most important components from the exergo-economic point of view, due to the high initial cost rate and Exergy destruction. The parametric analysis result shows that the temperature increase in the evaporator has a positive effect on cycle operation and, the increase in pinch point temperature difference of evaporator has a negative effect on cycle operation. From an economic point of view, the increase in evaporator and pinch point temperature difference of evaporator causes the decrease in capital coast rate. Also, the solar radiation change finds to have a positive effect on system operation, based on an exergo-economic point of view, which causes the increase in energy and exergy efficiency.