Wilson Plot 방법을 적용한 막 응축용 전열촉진관들의 열전달 및 압력강하 특성비교

• Published in: 설비공학 논문집, 30(7) Vol. 30; no. 7; pp. 336 - 345
• Main Authors: 전동순(Dong-Soon Jeon), 고지운(Ji-Woon Ko), 정기문(Ki Moon Jung), 김성민(Seong Min Kim)
• Format: Journal Article
• Language: Korean
• Published: 대한설비공학회 2018
• Subjects: 기계공학; Heat transfer coefficient(열전달계수); Film condensation(막 응축); Enhanced tube(전열촉진관); R134a; R1234ze(E)
• ISSN: 1229-6422; 2465-7611
• DOI: 10.6110/KJACR.2018.30.7.336

In this study, experimental investigations were carried out to compare the heat transfer and pressure drop characteristics of enhanced tubes using film condensation. Five enhanced tubes were selected for the performance comparison experiment. The velocity of the coolant ranged from 1.4 m/s to 2.6 m/s. The saturated condensation temperature, fixed at $38^{\circ}C$. R134a and R1234ze(E), were used as refrigerants. The resulting outside and inside heat transfer coefficients were between $11.04kW/m^2{\cdot}K$ and $21.30kW/m^2{\cdot}K$ and between $10.38kW/m^2{\cdot}K$ and $24.69kW/m^2{\cdot}K$. The film condensation heat transfer coefficients of R134a showed an average of about 10% higher than that of R1234ze(E). The heat transfer rate of enhanced tube number 4 obtained from the experiment was about 36% higher than that of enhanced tube number 1. This study proposed a performance comparison of enhanced tubes and development of experimental heat transfer correlations for coolant. In the present study, an experimental correlation of the Nusselt number for the coolant was proposed, and this correlation has a ${\pm}20%$ margin of error.