Integration of a Thermoelectric Subcooler into a Carbon Dioxide Transcritical Vapor Compression Cycle Refrigeration System

摘要

Thermoelectric (TE) modules have been integrated into a subcooler of an experimental CO_2 transcritical vapor compression cycle test system. The TE Subcooler was designed and fabricated to subcool CO_2 exiting the gas cooler to a temperature below ambient. The heat from the TE Subcooler was rejected to the ambient utilizing a separate thermosyphon refrigerant loop with a separate condenser. The thermoelectric modules operate at efficiencies greater than the baseline system, increasing capacity and the overall coefficient of performance (COP) of the entire system. Additionally, subcooling of the CO_2 before the expansion device leads to a reduced optimum gas cooling pressure, resulting in greater COP improvement that cannot be achieved in conventional refrigerant vapor compression systems utilizing a TE Subcooler. The use of a simple aluminum microchannel TE Subcooler was shown to increase the COP of the system by 5% and increase the capacity by 15%.