Experimental comparison of the performance of basic and regenerative organic Rankine cycles

Adding the regenerator to recover extra heat from the exhaust can improve the system overall performance. Based on a 10 kW organic Rankine cycle (ORC) experimental prototype, a comparison between the basic and regenerative organic Rankine cycle is investigated. The heat input is in range of 30–90 kW and R245fa is used as working fluid. The heat source temperature utilization rate is defined to appraise the heat source utilization. The detailed behaviors for heat source loop, ORC loop and cooling water loop are examined. Research demonstrates that the BORC has a better heat source temperature utilization than the RORC. RORC has a maximum thermal efficiency of 5.5%, which is 25.5% higher than BORC of 4.1%. The maximum condenser heat transfer coefficients for BORC and RORC are 501.4 W/m² K and 1701.4 W/m² K, respectively. The BORC has higher electrical power and generating efficiency than the RORC. The maximum generating efficiency for BORC is 3.4%, while that for RORC is 2.5%. Besides, the exergy destructions of the main components are addressed, and the evaporator has a very large percentage of exergy destruction for BORC and RORC. Therefore, system performance can be heightened by improving the temperature difference matching of the heat sources.