Experimental Study on Condensation Heat Transfer and Flow Modes of R245fa on Enhanced Surface Tubes

2015 ◽  
Vol 23 (02) ◽  
pp. 1550014 ◽  
Author(s):  
Daisuke Jige ◽  
Tomonobu Matsuno ◽  
Norihiro Inoue
Keyword(s):  
Heat Transfer ◽  
Saturation Temperature ◽  
Condensation Heat Transfer ◽  
Flow Mode ◽  
Heat Transfer Characteristics ◽  
Enhanced Heat Transfer ◽  
Finned Tubes ◽  
Transfer Characteristics ◽  
Grooved Tube ◽  
Enhanced Surface

The present study experimentally investigated the condensation heat transfer characteristics and condensate flow mode of R245fa on horizontal low-finned and microscopic-grooved tubes. Five low-finned tubes and a microscopic-grooved tube with tube diameters at the fin tip of approximately 19 mm were used. Experiments were conducted at a saturation temperature of 40°C. The fundamental heat transfer characteristics of the low-finned and microscopic-grooved tubes were experimentally investigated to clarify the flow modes of the condensate and the efficacy of the enhanced heat transfer.

Condensation heat transfer characteristics of moist air outside 3-D finned tubes with different wettability

Energy ◽  
2020 ◽  
Vol 207 ◽  
pp. 118202 ◽  
Author(s):  
Yuheng Gu ◽  
Yudong Ding ◽  
Qiang Liao ◽  
Qian Fu ◽  
Xun Zhu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Condensation Heat Transfer ◽  
Moist Air ◽  
Heat Transfer Characteristics ◽  
Finned Tubes ◽  
Transfer Characteristics

Condensation Heat Transfer Characteristics of R134A on Smooth or Finned Horizontal Tube

2005 ◽  
Author(s):  
M. Fatouh
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Flow Rate ◽  
Condensation Heat Transfer ◽  
Heat Transfer Characteristics ◽  
Finned Tubes ◽  
Overall Heat Transfer Coefficient ◽  
Transfer Characteristics

The present work aimed at determining the condensation heat transfer characteristics of R134a on single horizontal smooth and finned tubes under different parameters. These are saturated temperature (36°C and 43°C), inlet coolant temperature (25°C and 30°C) and coolant mass flow rate (100: 800 kg/h) for smooth and finned tubes. In the case of finned tubes, the pitch to height ratio varies from 0.5 to 3.08. Experimental condensation heat transfer characteristics for R134a and R12 on a smooth tube are compared. Experimental results confirmed that the heat flux and the overall heat transfer coefficient for R134a increase when coolant mass flow rate, saturation temperature and fin height increase or as both coolant inlet temperature and fin height decrease. The influence of fin pitch, on condensation heat flux and overall heat transfer, is lower than that of fin height. However, the heat flux and the overall heat transfer coefficient for R134a are correlated with the investigated parameters. Finally, the comparison between R12 and R134a revealed that the condensation heat transfer characteristics for R134a are better than those of R12.

Study on Condensation Heat Transfer Characteristics of Nonazeotropic Binary Refrigerant Mixture R1234yf/R32 Inside Small-Scale Horizontal Smooth Tubes

2013 ◽  
Author(s):  
Linlin Wang ◽  
Chaobin Dang ◽  
Eiji Hihara
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Saturation Temperature ◽  
Condensation Heat Transfer ◽  
Small Scale ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Refrigerant Mixture ◽  
Mass Fluxes ◽  
Binary Refrigerant

In this study, condensation heat transfer characteristics of nonazeotropic mixtures R1234yf and R32 (mass fractions of 0.52:0.48 and 0.77:0.23, respectively) inside a horizontal smooth tube (inner diameter 2 mm) were experimentally investigated at mass fluxes ranging from 100 to 400 kg/m2 s and at a saturation temperature of 40 °C. A prediction model using a modified heat transfer correlation for pure refrigerant was constructed, the details of which are presented here. The heat transfer characteristics, especially the heat transfer deterioration caused by the mass transfer difference of the nonazeotropic refrigerant mixture, were evaluated by combining the correlations of heat transfer and mass transfer on both the vapor side and the liquid side. Through comparison with experimental data, the obtained prediction results were found to agree reasonably with the experimental condensation heat transfer coefficient of binary refrigerant mixtures using R1234yf and R32.

Sign in / Sign up

Export Citation Format

Share Document