미세사각채널에서 CO₂의 이상유동 양식에 관한 연구

The heat transfer and pressure drop characteristics of CO₂ are substantially different from those for CFC and HCFC refrigerants. In addition, geometric effects on two-phase flow patterns of CO₂ are also very significant in many respects. Therefore, two-phase flow patterns of CO₂ in a narrow rectangular channel or a small diameter tube whose gap size or hydraulic diameter is less than 2 mm are very important to understand heat transfer characteristics and to develop an appropriate heat transfer correlation. In the present study, the evaporation process of CO₂ in a narrow rectangular channel is visualized at various test conditions, and then the effects of operating conditions are analyzed.