R-1234yf의 관경 변화에 따른 응축 열전달 특성
Condensation Heat Transfer Characteristics of R-1234yf with the Variation of Tube Diameter
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In this study, the condensation heat transfer characteristics of the R-1234yf refrigerant were analyzed according to the variation in tube diameter, which were then considered as condenser design data. The inner diameter of the experimental tube was varied from 3.7 mm to 5.3 mm. Subsequently, the heat transfer coefficient of R-1234yf was analyzed according to the changes in vapor quality, mass flux, saturation temperature, and pipe diameter. Slug flow was observed at a low mass flux, and annular flow was observed at a high mass flux. Furthermore, it was observed that the heat transfer coefficient’s value increased with increase in the vapor quality and mass flux, whereas it decreased with increase in the tube diameter and saturation temperature. By comparing the heat transfer coefficients of the refrigerants R-134a and R-1234yf, it was found that the heat transfer coefficient of R-134a is higher. Furthermore, four correlations were conducted, and it was found that the correlation of Dobson and Chato and the correlation of Bashar can predict the experimental condensation heat transfer coefficient within an error range of ±10%.
Abstract
In this study, the condensation heat transfer characteristics of the R-1234yf refrigerant were analyzed according to the variation in tube diameter, which were then considered as condenser design data. The inner diameter of the experimental tube was varied from 3.7 mm to 5.3 mm. Subsequently, the heat transfer coefficient of R-1234yf was analyzed according to the changes in vapor quality, mass flux, saturation temperature, and pipe diameter. Slug flow was observed at a low mass flux, and annular flow was observed at a high mass flux. Furthermore, it was observed that the heat transfer coefficient’s value increased with increase in the vapor quality and mass flux, whereas it decreased with increase in the tube diameter and saturation temperature. By comparing the heat transfer coefficients of the refrigerants R-134a and R-1234yf, it was found that the heat transfer coefficient of R-134a is higher. Furthermore, four correlations were conducted, and it was found that the correlation of Dobson and Chato and the correlation of Bashar can predict the experimental condensation heat transfer coefficient within an error range of ±10%.
참고문헌 (18)
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