Condensation heat transfer of R410A on outside of horizontal smooth and three-dimensional enhanced tubes

2019 ◽  
Vol 98 ◽  
pp. 1-14 ◽  
Author(s):  
Wei Li ◽  
Zhi-chuan Sun ◽  
Rui-heng Guo ◽  
Xiang Ma ◽  
Zhi-chun Liu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Condensation Heat Transfer ◽  
Enhanced Tubes

Shell-Side Flow Condensation Heat Transfer on Three-Dimensional Enhanced Surface

2021 ◽  
pp. 1-20
Author(s):  
Wei Li ◽  
Desong Yang ◽  
Jingxiang Chen ◽  
Zhichuan Sun ◽  
Jiacheng Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mass Flux ◽  
Three Dimensional ◽  
Condensation Heat Transfer ◽  
Shell Side ◽  
Enhanced Tubes ◽  
Plain Tube ◽  
Flow Condensation ◽  
Side Flow

Abstract An experimental investigation of shell-side flow condensation was performed on advanced three-dimensional surface-enhanced tubes, including a herringbone micro-fin tube and a newly-developed 1-EHT tube. An equivalent plain tube was also tested for performance comparison. All the test tubes have similar geometry parameters (inner diameter 11.43mm, outer diameter 12.7mm). Tests were conducted using R410A as the working fluid at a condensation saturation temperature of 45·C, covering the mass flux range of 10-55 kg/(m2·s) with an inlet quality of 0.8 and an outlet quality of 0.1. Experimental results showed that the plain tube exhibits a better condensation heat transfer performance when compared to the enhanced tubes. Moreover, the mass flux has a significant influence on the best transfer coefficient for shell-side condensation. A new prediction model based on the Cavallini's equation was developed to predict the condensing coefficient where the mean absolute error is less than 4%.

Condensation of R-134a on Horizontal Enhanced Tubes Having Three-Dimensional Roughness

2016 ◽  
Vol 24 (02) ◽  
pp. 1650013 ◽  
Author(s):  
Nae-Hyun Kim
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
High Heat ◽  
Condensation Heat Transfer ◽  
Transfer Coefficients ◽  
Process Industries ◽  
High Heat Transfer ◽  
Enhanced Tubes ◽  
R 134A ◽  
Geometric Variation

Enhanced tubes are widely used in shell and tube condensers of refrigeration, air-conditioning and process industries because of their high heat transfer performance. In this study, condensation heat transfer tests were conducted for four three-dimensional enhanced tubes having different fin density and fin height using R-134a. The satuartion temperature was 40[Formula: see text]C. The heat transfer was significantly enhanced by the present enhanced geometry. At 5[Formula: see text]K wall subcooling, the enhancement ratio is 6.3 for 1654[Formula: see text]fpm, 4.6 for 1575[Formula: see text]fpm, 4.0 for 1496[Formula: see text]fpm and 3.3 for 1102[Formula: see text]fpm tubes. Within the geometric variation of the present study, the condensation heat transfer coefficient increased with the increase of fin density and of fin height. The heat transfer coefficients of the 1654[Formula: see text]fpm tube were approximately the same as those of the commercial three-dimensional enhanced tube Turbo-C.

Experimental Investigation of Shell-Side Flow Condensation on Three-Dimensional Enhanced Surface Tubes

2020 ◽  
Author(s):  
Desong Yang ◽  
Zhichuan Sun ◽  
Wei Li
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Mass Flux ◽  
Three Dimensional ◽  
Condensation Heat Transfer ◽  
Shell Side ◽  
Plain Tube ◽  
Side Flow ◽  
The Heat Transfer Coefficient

Abstract An experimental investigation of shell-side flow condensation heat transfer was performed on advanced three-dimensional surface-enhanced tubes, including a herringbone micro-fin tube and a newly-developed 1-EHT tube. An equivalent plain tube was also tested for performance comparison. All of the test tubes have similar geometry parameters (inner diameter 11.43mm, outer diameter 12.7mm). Tests were conducted using R410A as the working fluid at a condensation saturation temperature of 45 °C, covering the mass flux range of 10–55 kg/(m2·s) with an inlet quality of 0.8 and an outlet quality of 0.1. Experimental results showed that the plain tube exhibits a better condensation heat transfer performance when compared to the enhanced tubes. Moreover, the mass flux has a significant influence on the heat transfer coefficient for shell-side condensation: the condensation heat transfer coefficient of plain tube decreases when the refrigerant mass flux becomes larger, while the heat transfer coefficient of herringbone tube shows a non-monotonic trend and the heat transfer coefficient of the 1-EHT tube gets higher with increasing refrigerant mass flux. Besides, A new prediction model based on the Cavallini’s equation was developed to predict the condensing coefficient of the three test tubes, and the mean absolute error of the improved equations is less than 4%.

Experimental Study on Flow Evaporation Heat Transfer Characteristics Inside Horizontal Three-Dimensional Enhanced Tubes

2018 ◽  
Author(s):  
Wei Li ◽  
Chuancai Zhang ◽  
Zhichuan Sun ◽  
Zhichun Liu ◽  
Lianxiang Ma ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Mass Flux ◽  
Three Dimensional ◽  
Outer Diameter ◽  
Evaporation Heat ◽  
Enhanced Tubes ◽  
Evaporation Heat Transfer ◽  
The Heat Transfer Coefficient

Experimental investigation was performed to measure the evaporation heat transfer coefficients of R410A inside three three-dimensional enhanced tubes (1EHT-1, 1EHT-2 and 4LB). The inner and outer enhanced surface of the 4LB tube is composed by arrays of grooves and square pits, while 1EHT-1 tube and 1EHT-2 tube consist of longitudinal ripples and dimples of different depths. All these tubes have an inner diameter of 8.32 mm and an outer diameter of 9.52 mm. Experiment operational conditions are conducted as follows: the saturation temperature is 279 K, the vapor quality ranges from 0.2 to 0.8, and the mass flux varies from 160 kg/(m2·s) to 380 kg/(m2·s). With the mass flux increasing, the heat transfer coefficient increases accordingly. The heat transfer coefficient of 1EHT-2 is the highest of all three tubes, and that of 1EHT-1 is the lowest. The heat transfer coefficient of 4LB ranks between the 1EHT-1 and 1EHT-2 tube. The reason is that the heat transfer areas of the 1EHT-2 and 4LB tube are larger than that of 1EHT-1 and interfacial turbulence is enhanced in 1EHT-2.

scholarly journals Three-Dimensional Superhydrophobic Nanowire Networks for Enhancing Condensation Heat Transfer

Joule ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 269-279 ◽  
Author(s):  
Rongfu Wen ◽  
Shanshan Xu ◽  
Xuehu Ma ◽  
Yung-Cheng Lee ◽  
Ronggui Yang
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Condensation Heat Transfer ◽  
Nanowire Networks

Condensation and Evaporation Heat Transfer Characteristics of Low Mass Fluxes in Horizontal Smooth Tube and Three-Dimensional Enhanced Tubes

2019 ◽  
Vol 12 (2) ◽  
Author(s):  
Xiang Ma ◽  
Wei Li ◽  
Chuan-cai Zhang ◽  
Zhi-chuan Sun ◽  
David J. Kukulka ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mass Flux ◽  
Three Dimensional ◽  
Saturation Temperature ◽  
Transfer Enhancement ◽  
Heat Transfer Characteristics ◽  
Evaporation Heat ◽  
Enhanced Tubes ◽  
Evaporation Heat Transfer ◽  
Enhanced Surface

Abstract An experimental investigation of condensation and evaporation heat transfer characteristics was performed in 15.88-mm-OD and 12.7-mm-OD smooth and three-dimensional enhanced tubes (1EHT, 3EHT) using R134A and R410A as the working fluid. The enhanced surface of the 1EHT tube is made up of dimples and a series of petal arrays; while the 3EHT tube is made up of rectangular cavities. Evaluations are performed at a saturation temperature of 45 °C, over the quality range of 0.8–0.2 for condensation; while for evaporation the saturation temperature was 6 °C and the quality ranged from 0.2 to 0.8. For condensation, the enhancement ratio (enhanced tube/smooth tube) of the heat transfer coefficients was 1.42–1.95 for the mass flux ranging from 80 to 200 kg/m2s; while for evaporation, the heat transfer enhancement ratio is 1.05–1.42 for values of mass flux that range from 50 to 180 kg/m2s. Furthermore, the 1EHT tube provides the best condensation and evaporation heat transfer performance, for both working fluids at the mass flux considered. This performance is due to the dimples in the enhanced surface that produce interface turbulence; additionally, the increased surface roughness causes additional disturbances and secondary flows near the boundary, producing higher heat fluxes. The main objective of this study was to evaluate the heat transfer enhancement of two enhanced tubes when using R134A and R410A as a function of mass flux, saturation temperature, and tube diameter. As a result of this study, it was determined that the heat transfer coefficient decreases with an increase in saturation temperature and tube diameter.

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