헬리컬 코일형 가스냉각기 내 CO₂의 냉각 전열 특성 = Heat Transfer Characteristics of Supercritical Carbon Dioxide in Helically Coiled Tubes

다국어 초록 (Multilingual Abstract)

The cooling heat transfer coefficient of CO₂ (R-744) in helically coiled tubes was investigated experimentally. The main components of the refrigerant loop are a receiver, a variable-speed pump, a mass flow meter, a pre-heater and a gas cooler (test section). The test section consists of a helically coiled copper tube of 4.55 and 2.45 ㎜. The experiments were conducted at saturation temperature of 100 to 20℃, and mass flux of 200 to 600 ㎏/㎡s. The test results showed the variation of the heat transfer coefficient tended to decrease as cooling pressure of CO₂ increased. The heat transfer coefficient with respect to mass flux increased as mass flux increased. The experimental results were also compared with the existing correlations for the supercritical heat transfer coefficient, which generally under-predicted the measured data. However, the experimental data showed a relatively good agreement with the correlations of Pitla et al. except for the pseudo critical temperature.

목차 (Table of Contents)

• ABSTRACT
• 1. 서론
• 2. 실험장치 및 방법
• 3. 실험결과 및 고찰
• 4. 결론
• 참고문헌