Performance analysis and exergoeconomic evaluation of a TRC system enhanced by a dedicated mechanical subcooling

•A comprehensive performance and exergoeconomic analysis is performed.•A mechanical subcooling is utilized for a TRC’s performance enhancement.•Carbon dioxide, ethane and nitrous oxide are selected as system refrigerants.•The highest COP belongs to N2O and CO2 is the best refrigerant from the economic viewpoint.•Using the subcooling has the highest influence on TRC with ethane refrigerant. In the present study, a transcritical refrigeration cycle’s performance with dedicated mechanical subcooling (MS) is investigated from the energy, exergy and exergoeconomic viewpoints. Three different refrigerants containing CO2 (R744), N2O (R744A) and ethane (R170) are considered as the transcritical cycle’s refrigerant. A thorough parametric study is carried out on the system and finally, the effect of dedicated subcooling system is checked out on the energy, exergy and exergoeconomic perimeters. Based on the results, value of the COP and exergy performance for N2O, unlike the CO2, is the highest. In other words, the CO2 refrigerant shows the best economic performance. By comparing the system with and without subcooling cycle, it can be concluded that utilizing subcooler improves performance of the system and increases the unit product cost. However, the unit product cost increment is much lower than COP improvement which makes the subcooling an effective and economical way to improve the refrigeration system’s performance. Application of subcooler leads to an enhancement of 30.74%, 26.48% and 36.1% in COP for CO2, N2O, and ethane, respectively while the unit product cost increment is 9.04%, 8.37% and 10.63% for the mentioned refrigerants, respectively.