Performance analysis of a modified trans-critical CO2 refrigeration cycle

Performance of a two-stage trans-critical CO2 refrigeration cycle, which contains internal heat exchanger, intercooler, ejector, and separator, has been analyzed after modification. Original cycle has been modified with extracting a line of saturated vapor flow from separator and feeding to the intercooler. The impacts of operational parameters such as gas cooler temperature, evaporator temperature, and gas cooler pressure, on the cycle performance have been investigated. Computed results showed that modified cycle improved the maximum coefficient of performance, COPmax, by 26.89% compared to the original cycle at a particular operation conditions. Meanwhile, this modification averagely decreased the exergy destruction rate by 18.6% compared to the original cycle.