Thermodynamic evaluation of a transcritical CO2 refrigeration system equipped with ORC, mechanical subcooling and expander

Emamifar, Armin

doi:10.30506/jmee.2025.2046877.1363

Thermodynamic evaluation of a transcritical CO2 refrigeration system equipped with ORC, mechanical subcooling and expander

Articles in Press

Document Type : Research Paper

Author

Armin Emamifar

Department of Mechanical Engineering, Faculty of Engineering, Ayatollah Boroujerdi University, Boroujerd, Iran.

10.30506/jmee.2025.2046877.1363

Abstract

In the present study, enhancing the performance of a transcritical refrigeration system is investigated. To do this, an ORC is employed to recover the waste energy of the compressor outlet stream. Moreover, the power of the ORC is used to operate a vapor compression refrigeration cycle which is used for subcooling the exit vapor of the gas cooler. Furthermore, an expander is used to produce more power. Thermodynamic modeling shows that application of ORC, Subcooling system and expander for evaporator temperature of -20°C and gas cooler temperature of 40 °C leads to an enhancement of 65.83% and 63.9% in COP and exergy efficiency, respectively. Moreover, the exgergy analysis indicates that in the presented cycles the compressor, the cascade heat exchanger the evaporator and the expansion valve have the maximum exergy destruction rates. The effect of gas cooler temperature, gas cooler pressure, evaporator temperature and ORC turbine inlet temperature on the cycle performance is also investigated.

Keywords

Transcritical refrigeration cycle

CO2

ORC

Mechanical subcooling

Expander

Subjects