Exergy-economic analysis of a hybrid combined supercritical Brayton cycle-organic Rankine cycle using biogas and solar PTC system as energy sources

Abstract

Environmental negative impacts of the fossil fuels and intermittent feature of the renewable energies have made their hybrid configurations as a potential solution to overcome their both weaknesses. This research focuses on exergetic, and economic evaluation of a novel hybrid combined supercritical Brayton Cycle-Organic Rankine Cycle in which Solar PTC system and Biogas are considered as the energy Sources. The exhaust heat from the Bryton cycle runs the Organic Rankine cycle while either solar energy (during the daylight hours) or biogas energy (overnight hours) supply additional heat into the Brayton cycle. Sensitivity analyses were carried out in order to ascertain the influence that the system's input characteristics. The total exergy destruction of the system as well as its second law efficiency are computed. The process was not complete until exergoeconomics was used, and it was during this stage that the initial investment rate, the exorgoeconomic component, and the investment return rate are figured out. The findings of these analyses are compiled into a result report. It was concluded that combining the PTC system with the source of the biogas could be an effective way to achieve the desired level of heat delivery to the system.

Keywords

• SPECO
• Economic
• Combined solar cycle
• Exergy
• ORC
• Heat exchanger