Towards the dual heat sources recovery applied by organic Rankine cycle: An experimental assessment

The organic Rankine cycle (ORC) is a potential methodology for the thermal-power conversion of renewable energy (geothermal, solar, etc.). Towards the energy integrated application, the single heat source driven ORC could not satisfy the industrial development. In this work, a R1233zd(E)-based ORC driven by dual heat sources has been experimentally studied, and the dynamic system characteristics were primarily carried out. Considering the higher-temperature heat source with 100 °C–130 °C and the lower-temperature heat source with 55 °C–85 °C, the behaviors of the devices are evaluated, and the overall system performance are compared. After that, the comprehensive analysis on the effect of heat source temperatures is developed from the energy and exergy aspects. The results show that the net output and thermal efficiency mostly depend on the higher-temperature heat source. Both of the increasing temperature of the two heat sources would contribute to the enhancement of exergy efficiency, due to the increase in net output and the decrease in exergy loss, respectively. The contribution of the coordinate of the two heat sources are highlighted. Considering the combinations of heat sources with 130 °C/55 °C, 100 °C/55 °C,100 °C/85 °C, 130 °C/85 °C, the thermal efficiencies are sequentially 9.19 %–8.26 %, 7.24 %–6.98 %, 7.38 %–7.35 %, 8.83 %–8.29 %, and the exergy efficiencies are 13.03 %–11.80 %, 10.59 %–10.27 %, 12.12 %–11.98 %, 13.82 %–13.16 % in sequence.