내부열교환기 및 전자팽창장치를 적용한 가변속 이산화탄소 사이클의 냉방성능에 관한 실험적 연구

Since a transcritical CO₂ cycle shows lower performance than conventional air conditioners in the cooling mode operation, it is required to enhance the performance of the CO₂ cycle by applying advanced technologies and optimizing components. In this study, the cooling performance of a CO₂ system measured by varying refrigerant charge amount, compressor frequency, EEV opening and length of internal heat exchanger. As a result, the cooling COP of the basic system without internal heat exchanger was 2.1. The cooling performance of the modified cycle applying internal heat exchanger improved by 4-9% over the basic cycle.