Performance estimation of regenerative organic rankine cycle using heat source from hot spring in Masaingi, Central Sulawesi, Indonesia

Abstract

Hot spring can be utilized as a heat source to produce electricity using organic Rankine cycle (ORC). Regenerative organic Rankine cycle (RORC) with a single stage turbine is used to improve the system performance of ORC. This paper discusses performance estimation (thermal and exergy efficiency) of single stage turbine RORC using hot spring in Masaingi, Central Sulawesi, Indonesia as a heat source. The energy and exergy analysis of RORC are evaluated and compared with basic ORC (BORC). Temperature and volume flow rate of the hot spring in Masaingi are used as initial data. R245fa has chosen an organic working fluid. Energy analysis is carried out by calculating heat input to determine mass flow rate, net power output, heat output and thermal efficiency. Exergy analysis is carried out by calculating exergy rate balance to determine exergy input, output, and exergy destruction for each component to gain total exergy destruction and exergy efficiency. The results show that performance of RORC system increase with higher hot spring temperature, and constant with higher volume flow rate. Comparison result shows that RORCincreases thermal and exergy efficiency for 23.7% and 23.5%, and decreases total exergy destruction rate by 24.5% than BORC.