Non-steady thermodynamic characteristics of a pilot-scale organic Rankine cycle system with a thermally-driven pump

A pilot-scale organic Rankine cycle (ORC) power generation system with a thermally-driven pump is constructed, and the working fluid of R245fa and a screw expander are adopted. Different heat source temperatures in the range of 90.00 degrees Ce130.0 0 degrees C and the ambient temperature around 22 degrees C are employed to investigate the performance of the ORC system in the thermally-driven mode. The experimental results show that the generated electrical power indicates a stable fluctuation with the maximum time-averaged power of 11.61 kW at the heat source temperature of 130.00 degrees C, and the peak and valley values of 13.9 kW and 7.2 kW, respectively. The maximum thermal efficiency of 4.3% and the exergetic efficiency of 20.9% are obtained at the heat source temperature of 130.00 degrees C and 100.00 degrees C, respectively. Meanwhile, the proportion of full width at half maxima (PFWHM) is defined to illustrate the fluctuation characteristics of the output power, and the value is always between 0.70 and 0.72 at different heat source temperatures. Finally, the performance of the thermally-driven ORC system is compared with that of the conventional ORC system, and the results show that the ORC system in the thermally-driven mode adapts better to the heat source temperature below 110.00 degrees C. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

A pilot-scale organic Rankine cycle (ORC) power generation system with a thermally-driven pump was constructed and investigated. The system showed stable fluctuation in electrical power output with maximum time-averaged power of 11.61 kW at a heat source temperature of 130.00 degrees C. The system also achieved maximum thermal efficiency of 4.3% and exergetic efficiency of 20.9% at heat source temperatures of 130.00 degrees C and 100.00 degrees C, respectively. The system's performance was compared with a conventional ORC system, and the thermally-driven ORC system performed better at heat source temperatures below 110.00 degrees C.