EFFECT OF TUBE PITCH ON POOL BOILING HEAT TRANSFER OF VERTICAL TUBE BUNDLE

2016 ◽  
Vol 13 (4) ◽  
pp. 485-496 ◽  
Author(s):  
Myeong-Gie Kang
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Tube Bundle ◽  
Pool Boiling ◽  
Vertical Tube ◽  
Pool Boiling Heat Transfer ◽  
Tube Pitch

scholarly journals Enhancement of Pool Boiling Heat Transfer over Plain and Rough Cylindrical Tubes

2021 ◽  
Vol 39 (2) ◽  
pp. 329-336
Author(s):  
Farhan M. Haidary ◽  
Md. Rabbi Hasan ◽  
Mohammad Adib ◽  
Sadman H. Labib ◽  
Md. Jubayer Hossain ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Roughness ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Orientation Angle ◽  
Horizontal Tube ◽  
Vertical Tube ◽  
Smooth Tube ◽  
Pool Boiling Heat Transfer

This study investigates the pool boiling heat transfer of water over cylindrical heating tubes for different orientations and surface roughness of the tubes. First, two orientations of a smooth heating tube, horizontal and vertical, were used in the boiling chamber. For a given heat flux, the heat transfer coefficient achieved with the horizontal tube was always higher than that for the vertical tube. To investigate the influence of surface roughness, a rough heating tube with a fully rough outer surface was developed through a metal etching process. Under the same range of wall superheat, the rough tube enhanced the heat transfer rate significantly compared to the smooth tube. Finally, a modified heating tube (MHT) was developed by axially roughening half of the surface of an originally smooth tube. The orientation angle of the rough surface of this MHT was varied from 0° (horizontal-upward) to 180° (horizontal-downward) in the chamber. The heat flux increased significantly with the increase of orientation angles from 0° to 90° (the maximum of 80 kW/m2 at 90°), whereas the same decreased as the orientation angle is further increased from 90° to 180°. Results revealed that the bubble dynamics over the heating tubes play a vital role in pool boiling performance.

EHD-Enhanced Boiling Coefficients and Visualization of R-134a Over Enhanced Tubes

1997 ◽  
Vol 119 (2) ◽  
pp. 332-338 ◽  
Author(s):  
K. Cheung ◽  
M. M. Ohadi ◽  
S. Dessiatoun ◽  
A. Singh
Keyword(s):  
Heat Transfer ◽  
Flow Visualization ◽  
Boiling Heat Transfer ◽  
Tube Bundle ◽  
Pool Boiling ◽  
Nucleate Boiling ◽  
Transfer Coefficients ◽  
Surface Geometry ◽  
Pool Boiling Heat Transfer ◽  
R 134A

In an earlier study by the authors, the applicability of the EHD technique for augmentation of pool boiling heat transfer of R-134a in a tube bundle was demonstrated. This paper reports additional experiments involving optimization of the electrode/heat transfer surface geometry as well as flow visualization studies that provide improved understanding of the EHD-enhanced pool boiling heat transfer in a tube bundle. Utilizing the flow visualization studies, it is demonstrated that combined electroconvection and improved nucleate boiling dynamics give rise to the augmented heat transfer coefficients.

Effects of a Flow Disturbing Plate on Pool Boiling Heat Transfer on a Vertical Tube

2003 ◽  
Author(s):  
Myeong-Gie Kang
Keyword(s):  
Heat Transfer ◽  
Atmospheric Pressure ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Vertical Tube ◽  
Tube Surface ◽  
Transfer Coefficients ◽  
Pool Boiling Heat Transfer ◽  
Heat Transfer Coefficients ◽  
Plate Width

Effects of the width and location of a flow disturbing circular plate, installed at a vertical tube surface, on nucleate pool boiling heat transfer of water at atmospheric pressure have been investigated experimentally. Through the tests, changes in the degree of intensity of liquid agitation have been analyzed. The plate changes the fluid flow around the tube as well as heat transfer coefficients on the tube surface. It is identified that the plate width changes the rate of the circulating flow whereas its location changes the growth of the active agitating flow. Moreover, the flow chugging was observed at the downside of the plate.

Nucleate Pool Boiling Heat Transfer in Microgravity

1998 ◽  
Vol 29 (1-3) ◽  
pp. 196-207
Author(s):  
Haruhiko Ohta ◽  
Koichi Inoue ◽  
Suguru Yoshida ◽  
Tomoji S. Morita
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Nucleate Pool Boiling ◽  
Pool Boiling Heat Transfer
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