An Evaluation of a New Solar-Assisted and Ground-Cooled Organic Rankine Cycle (ORC) with a Recuperator

Abstract

This study investigated a new solar-powered and ground-source cooling organic Rankine cycle (ORC) system. In the analysis of the ORC system, three different working fluids, namely toluene, cyclohexane, and isopentane, were used, as well as therminol 66 as thermal oil in the solar energy cycle. The difference in the designed system lies in the technique of cooling the heat generated in the condenser part with soil. Moreover, system efficiency was investigated for condenser temperature, collector surface area, soil temperature, and different radiation values. The variation of condenser temperature with three different working fluids was evaluated for two different evaporator pressures. As a result, the ORC system efficiency increased at a lower condenser temperature. When the condenser temperature was reduced from 60 to 30 degrees C, the ORC efficiency increased for cyclohexane, toluene, and isopentane fluids in the following order: 0.251-* 0.293, 0.2798-* 0.3183 and 0.1707-* 0.2148. In the last part of the study, hourly analysis was made for the days of the 15th of January and the 15th of June in a selected region using meteorological data. The ORC efficiency (eta orc) was calculated as 0.2997 and 0.2808 for these days, respectively.