A recent study on the performance of Organic Rankine Cycle (ORC) systems has shed light on the efficiency of these systems under different operating conditions. Conducted by researchers Jian Sun and Bin Peng, the research aims to advance the utilization of low-temperature waste heat, which remains largely untapped, and contribute to more sustainable energy practices.
ORC technology is gaining traction due to its ability to convert low-grade heat to power, addressing the need for energy conservation and reduced carbon emissions. The authors conducted experiments with three organic fluids—R245fa, R134a, and R227ea—within a 3 kW ORC system, testing six distinct operational conditions to analyze performance parameters such as power generation and thermodynamic efficiency.
The experiments revealed significant insights. For example, the research found the maximum generator power conversion efficiency reached 64.651% under controlled conditions. Such efficiency indicates the potential of ORC systems to effectively convert biomass or waste heat from industrial processes, enhancing overall energy productivity.
Interestingly, the study highlighted how the cooling water temperature (CWT) influences the performance of the ORC system components. The researchers reported, "The CWT affected the performance of working components by influencing the temperature and pressure of working fluids...essentially affecting all operating parameters of the system." This emphasizes the importance of maintaining optimal cooling conditions for improved system output.
The results also underscored how net system work and power generation serve as key metrics for evaluating heat source utilization efficiency, presenting findings relevant to engineers and scientists alike seeking to advance energy recovery methods. A maximum net power of 1.019 kW and maximum net work of 1.321 kW were recorded, providing benchmarks for future system optimizations.
The study concluded with recommendations for future research, stating, "To reduce the exergy loss in evaporators, the system structure should be improved or a mixture of working fluids should be used." This insight suggests potential paths toward enhancing the economic and environmental performance of ORC systems.
Through detailed experimental assessments, the authors aim to guide the development of ORC technologies, enabling them to play a more significant role in energy recovery applications and supporting the global transition toward cleaner energy solutions.