Abstract
In order to improve a refrigeration system’s energy efficiency, the separation efficiency of its oil separator should be improved. To do so, we turned to nature for inspiration. A Namib Desert beetle collects water in fog by using its skin, which combines hydrophilic and hydrophobic surfaces. Inspired by nature’s design, we applied a surface with oleophilic and oleophobic patterns to an oil separator used in a refrigeration system. In order to make the oil separator, an appropriate design was established using computational fluid dynamics. A cyclone-type oil separator was produced with an oleophobic-treated surface on its lower cup. The efficiency of the treated surface of this oil separator was tested with an open-type experimental setup using an oil mist generator. To obtain conditions similar to those of a refrigeration system in the open-type experimental setup, the oil particle diameter and working fluid pressure were set to yield a Stokes number similar to that of oil particles in the oil separator of the refrigeration system. The oil separator with the treated oleophilic–oleophobic surface improved its oil separation efficiency by 1.67% and its pressure drop by 2.48% compared to a conventional cyclone-type oil separator.
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Abbreviations
- D :
-
Cyclone diameter [m]
- d p :
-
diameter [m]
- Q d :
-
Amount of oil remaining in the oil mist generator [mL]
- Q t :
-
Amount of oil trapped in the oil separator [mL]
- Q :
-
Flow rate of gas and oil [m/s]
- Stk :
-
Stokes number
- x ef :
-
Oil separation efficiency
- µ g :
-
Viscosity of gas [kg/ms]
- ρ g :
-
Density of gas [kg/m]
- ρ p :
-
Density of particle [kg/m]
References
Nørgaard, T. and Dacke, M., “Fog-Basking Behaviour and Water Collection Efficiency in Namib Desert Darkling Beetles,” Frontiers in Zoology, Vol. 7, No. 23, pp. 23–30, 2010.
Barthwal, S., Kim, Y. S., and Lim, S.-H., “Superhydrophobic and Superoleophobic Copper Plate Fabrication using Alkaline Solution Assisted Surface Oxidation Methods,” Int. J. Precis. Eng. Manuf., Vol. 13, No. 8, pp. 1311–1315, 2012.
Neto, M. A. M. and Barbosa, J. R., “A Departure-Function Approach to Calculate Thermodynamic Properties of Refrigerant-Oil Mixtures,” International Journal of Refrigeration, Vol. 36, No. 3, pp. 972–979, 2013.
Biancardi, F. R., Michels, H. H., Sienel, T. H., and Pandy, D. R., “Study of Lubricant Circulation in HVAC Systems,” United Technologies Research Center, ARTI MCLR Proiect, No. 665-53100, 1996.
Huang, X., Ding, G., Hu, H., Zhu, Y., Gao, Y., and Deng, B., “Flow Condensation Pressure Drop Characteristics of R410A-Oil Mixture Inside Small Diameter Horizontal Microfin Tubes,” International Journal of Refrigeration, Vol. 33, No. 7, pp. 1356–1369, 2010.
Kang, B. H., Kim, K. J., and Lee, S. K., “An Experimental Study on Oil Separation Characteristics of CO2/PAG Oil Mixture in an Oil Separator,” International Journal of Air-Conditioning and Refrigeration, Vol. 17, No. 3, pp. 88–93, 2009.
Cho, Y.-S., Lee, S.-W., Woo, K.-S., Yoon, Y.-B., Park, Y.-J., Lee, D.-Y., Kim, H.-C., and Na, B.-C., “A Numerical Analysis of Flow Characteristics and Oil Separation Performance for Cyclone Oil Separator Designs,” Transactions of the Korean Society of Automotive Engineers, Vol. 16, No. 5, pp. 22–28, 2008.
Shi, L. and Bayless, D. J., “Comparison of Boundary Conditions for Predicting the Collection Efficiency of Cyclones,” Powder Technology, Vol. 173, No. 1, pp. 29–37, 2007.
Rhodes, M. J., “Introduction to Particle Technology,” John Wiley & Sons, pp. 176–191, 2008.
Shin, H. S. and Kim, Y. J., “Oil Behaviors in Oil Separator with Various Discharge of Compressor Oil,” Proc. of the KSME Fluid Eng. Division Spring Annual Meeting, pp. 28–29, 2010.
Kang, W. M., Kim, A. R., Lee, D. Y., and Ko, H. S., “A Study on Cyclone Flow Inside Oil Separator,” Proc. of the KSME Fluid Eng Division Spring Annual Meeting, pp. 330–331, 2011.
Lebreton, J.-M., Vuillame, L., Morvan, E., and Lottin, O., “Oil Concentration Measurement in Saturated Liquid Refrigerant Flowing Inside a Refrigeration Machine,” International Journal of Applied Thermodynamics, Vol. 4, No. 1, pp. 53–60, 2001.
Kim, J., Byun, D., and Ko, H., “Experimental Study on Slip Flows in Superhydrophobic Microchannel,” Proc. of the Korean Society of Visualization Division Fall Meeting, pp. 84–87, 2007.
Park, C. Y., Bae, S. I., Lee, S. M., Ko, J. S., and Chung, K. H., “Friction Drag Reduction using Microstructured Surfaces,” J. Korean Soc. Precis. Eng., Vol. 26, No. 12, pp. 117–122, 2009.
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Jang, S., Ahn, J. & Lim, S.H. Performance of oil-separator adopting nature-inspired surface. Int. J. Precis. Eng. Manuf. 16, 2205–2211 (2015). https://doi.org/10.1007/s12541-015-0284-x
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DOI: https://doi.org/10.1007/s12541-015-0284-x