Thermodynamic analysis of Supercritical CO2 Partial Cooling Cycle integrated with two Organic Rankine Cycles

Abstract

This paper presents an innovative approach for increasing the thermal efficiency of supercritical CO2 (SCO2) power cycles by incorporating partial cooling with a two-bottom organic rankine cycle (ORC). The SCO2 power cycles have gained significant attention in recent years as a promising alternative to traditional power cycles due to their high thermal efficiency, but there is still room for improvement. The proposed approach aims to achieve this by utilizing the heat rejected by the SCO2 cycle to generate additional power through an ORC, and by using multiple working fluids with different temperature and pressure ranges in the ORC. The partial cooling cycle has emerged as a promising solution to reduce energy consumption and environmental impact. This comprehensive literature review examines the key concepts, advantages, limitations, and recent advancements related to the partial cooling cycle. The partial cooling method involves extracting a portion of the heat rejected by the SCO2 cycle and using it to generate power through an ORC. This approach increases the thermal efficiency of the SCO2 cycle by utilizing the otherwise wasted heat. The two-bottom ORC, on the other hand, allows the use of multiple working fluids with different temperature and pressure ranges. This can be beneficial because it can select the most appropriate working fluid for each temperature range, leading to an increase in the thermal efficiency of the ORC. The performance of the proposed method was evaluated using thermodynamic modelling, and the results showed that it has the potential to increase the overall thermal efficiency of the SCO2 power cycle by up to 10%. Additionally, this approach reduces the temperature difference between the 5 heat source and sink, leading to a decrease in irreversibilities and an increase in the thermal efficiency of the ORC. The review explores the fundamental concepts, advantages, limitations, and recent advancements related to this integrated approach. By examining a range of studies and publications, this review offers valuable insights into the performance, feasibility, and potential applications of the partial cooling cycle integrated with ORCs in different settings. In conclusion, the proposed approach of combining partial cooling with a two-bottom ORC has the potential to improve the thermal efficiency of SCO2 power cycles. The results of this study demonstrate that this approach is a promising solution for increasing the performance of SCO2 power cycles. More research is needed, however, to fully evaluate the feasibility of implementing this method in real-world applications