| Authors | Seyed Ali Reza Hosseini Nasab, Ebrahim Nemati Lay |
|---|---|
| Conference Title | 11th International Energy Conference |
| Holding Date of Conference | 2016-5-30 |
| Event Place | تهران |
| Presentation | SPEECH |
| Conference Level | International Conferences |
Abstract
Numerous studies have been done to improve the efficiency of energy storage systems. In order to determine the optimum operating conditions of solar energy storage systems, exergy analysis combined with energy analysis must be performed. In this paper, by presenting a suitable model, a method is presented for accurate evaluation of irreversibility of solar energy storage systems. In this model, a special type of shell and tube heat exchanger is used, as the tubular structure of the converter is of a two-tube type, with a static phase-shifting material on their outer wall to store solar thermal energy. Considering the effects of temperature and pressure on the thermophysical properties of heat carrier fluid and avoiding unrealistic assumptions, a detailed analysis of the irreversibility and therefore exergy analysis of solar energy storage systems can be performed. The results show that firstly, by selecting the multiple phase shift materials with tandem alignment, the overall exergy efficiency of the system can be improved. Second, increasing the fluid inlet pressure of the heat carrier reduces the irreversibility of the system and thereby improves the exergy efficiency of the system. Thirdly, to optimize the conditions and improve the overall exergy efficiency, the mass value of each phase shifting material must be chosen in a way that is equal to the capacity of the individual phase shifting materials