Thermodynamic performance of a supercritical CO₂ cycle integrated with a recuperative absorption cooling system

Supercritical CO₂ (sCO₂) cycles have been intensively investigated in the last decade and continued improvements in the cycle thermal efficiency is demonstrated using different cycle configurations. The performance of these cycles is significantly affected as the sCO₂ compressor inlet temperature moves away from the critical point which would be a function of ambient temperature. The precooler inlet temperature for a simple recuperative sCO₂ cycle is in the range of 100-120 °C, and varies based on the recuperator effectiveness, compressor inlet temperature and cycle pressure ratio changes. This work explores the potential benefits of integrating an absorption chiller to recuperate the waste heat of the sCO₂ cycle to produce combined power and cooling. The combined power generation and cooling can significantly improve the primary energy utilisation efficiency as compared to its individual productions. In the proposed cycle, part of the cold energy is utilised for power block cooling and the rest for space cooling. This approach will not only allow the performance of the power plant to be less dependent on ambient conditions but also enhance the efficiency and allow reduction in the power plant water consumption. Thermodynamic analysis shows that the proposed integrated cycle efficiency can be enhanced up to 5% at an ambient temperature of 50 °C. In addition, the absorption chiller is capable of providing 1300 tons of space cooling when the chiller is isolated from the pre-cooler, at a temperature of 45 °C in the case of a 10 MW_e sCO₂ power plant.