Thermodynamic analysis of a new hybrid system combined heat and power integrated solid oxide fuel cell, gas turbine, Rankine steam cycle with compressed air energy storage

Abstract

The combined systems of solid oxide fuel cell-gas turbine (SOFC-GT) can operate with high efficiency and low carbon emissions. However, air compressors power consumption of SOFC-GT is big. In this study, a novel hybrid system integrated SOFC-GT with compressed air energy storage (CAES) is proposed. For the integrated system, the energy efficiency is improved in comparison to traditional SOFC-GT due to no air compressors power consumption in the discharging process. In addition, Rankine steam cycle (RSC) is applied to recover waste heat of SOFC-GT exhaust. The new system is simulated in Aspen plus software. The energy and exergy analysis is investigated. Then, the sensitivity analysis is also studied. The results show the cycle efficiency, electrical cycle efficiency and exergy cycle efficiency of new energy storage can reach 75.98%, 60.49% and 60.79%, respectively. Besides, SOFC has the largest exergy destruction of all components. In conclusion, the new system can provide theoretical guidance for efficient energy utilization.