Investigation of the Effect of Using Different Nanofluids on the Performance of the Organic Rankine Cycle

Energy consumption worldwide continues to increase due to factors such as population growth, rural-to-urban migration, technological advancements, and the rising use of technological products that make life easier. As a result, there is a growing demand for renewable energy sources in energy supply, and technological research is conducted to address energy losses and improve existing systems for more efficient energy use. The Organic Rankine Cycle (ORC) is a thermodynamic cycle used for converting heat energy, similar to the Clausius-Rankine cycle. With evolving technology and increasing energy needs, studies related to the Organic Rankine Cycle are of great interest to researchers. This study examines the impact of adding nano-particles to the working fluids used in the ORC system on its performance. Seven different working fluids were selected, including R141b, R123, R142b (isentropic), R22, and R32 (wet), as well as R114 and R600 (dry). Performance was calculated for 14 different nano-fluids created by adding Al2O3 and TiO2 nano-particles to the working fluids. The EES software was used in the analyses. Among the types of working fluids, it was observed that isentropic working fluids were more suitable for the ORC system, particularly R141b and R123. When considering the working fluid type for the ORC system, it was found that isentropic working fluids achieved higher efficiency, followed by dry-type working fluids. The lowest efficiency values were obtained for R22 and R32 working fluids.