Enhancement of Condensation Heat Transfer Rate of the Air-Steam Mixture on a Passive Condenser System Using Annular Fins
Abstract
:1. Introduction
2. Experiment
2.1. Experimental Apparatus
2.2. Data Reduction
3. Results and Discussion
3.1. Experimental Results
3.2. Applicability to a Bundle Layout
4. Conclusions
- (a)
- The visualization results showed that the inflow of the condensate from an upper fin resulted in the periodic flooding of the liquid film on lower fins, and a thick film was retained on the upper surfaces of the annular disk due to the surface tension.
- (b)
- It was experimentally demonstrated that the total rate of condensation heat transfer was enhanced by the annular fins; the average enhancement factor was 1.54, which was obtained when the heat transfer area was increased by 84%. The average heat flux was degraded due to the disturbance of the parallel flow of the vapor-gas mixture to a condensing surface by the annular fin, and the large thermal resistance formed by the stored thick liquid film on the disk. Consequently, the condensation heat transfer coefficient of the annular finned tube was slightly lower than that of the bare tube.
- (c)
- The annular fin is thought to be a more practical option than the longitudinal fin for the PCCS since it can permit the influx of steam to the interior tubes when it is arranged in a bundle layout. A fin design to facilitate the drainage of the stored condensate on the disk will enhance the efficiency of the annular finned tube.
Acknowledgments
Author Contributions
Conflicts of Interest
References
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Pressure (bar) | Air Mass Fraction (%) | Wall Subcooling (K) | Coolant Mass Flow Rate (kg/s) |
---|---|---|---|
2 | 30~70 | 34.2~36.4 | 0.13~0.25 |
3 | 32.7~40.8 | 0.12~0.26 | |
4 | 38.2~40.3 | 0.12~0.35 | |
5 | 33.4~41.5 | 0.11~0.31 |
Parameter | Measurement Instrument | Bias Error |
---|---|---|
Fluid temperature | Thermocouple (K-type) | 0.2 K |
Wall temperature | Thermocouple (K-type) | 1.1 K |
Coolant flow rate | Electrical flow meter | 0.1% of span |
Chamber pressure | Pressure transmitter | 0.075% of span |
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Jang, Y.-J.; Choi, D.-J.; Kim, S.; Hyun, M.-T.; Lee, Y.-G. Enhancement of Condensation Heat Transfer Rate of the Air-Steam Mixture on a Passive Condenser System Using Annular Fins. Energies 2017, 10, 1777. https://doi.org/10.3390/en10111777
Jang Y-J, Choi D-J, Kim S, Hyun M-T, Lee Y-G. Enhancement of Condensation Heat Transfer Rate of the Air-Steam Mixture on a Passive Condenser System Using Annular Fins. Energies. 2017; 10(11):1777. https://doi.org/10.3390/en10111777
Chicago/Turabian StyleJang, Yeong-Jun, Dong-Jae Choi, Sin Kim, Myung-Taek Hyun, and Yeon-Gun Lee. 2017. "Enhancement of Condensation Heat Transfer Rate of the Air-Steam Mixture on a Passive Condenser System Using Annular Fins" Energies 10, no. 11: 1777. https://doi.org/10.3390/en10111777
APA StyleJang, Y.-J., Choi, D.-J., Kim, S., Hyun, M.-T., & Lee, Y.-G. (2017). Enhancement of Condensation Heat Transfer Rate of the Air-Steam Mixture on a Passive Condenser System Using Annular Fins. Energies, 10(11), 1777. https://doi.org/10.3390/en10111777