Experimental evaluation of needle electrode polarity variations effect on enhancement of water evaporation with electrohydrodynamic method

Authors

Abstract

Enhancement of forced flow evaporation rate by applying electric field (corona wind) has been experimentally evaluated in this study. Corona wind produced by a fine needle electrode which is charged with positive and negative high DC voltage impinges to water surface and leads to evaporation enhancement by disturbing the saturated air layer over water surface. The study is focused on the effect of corona wind velocity, electrode spacing and air flow velocity on the level of evaporation enhancement. Two sets of experiments, i.e. with and without electric field, have been conducted. Data obtained from the first experiment are used as reference for evaluation of evaporation enhancement at the presence of electric field. The results show that Maximum enhancement was 29.1154% for positive corona at air velocity of 1.75 m/s and electrode spacingof 3 cm, respectively the evaporation enhancement has been increases with change high DC voltage negative to positive and decreases whit increasing the electrode spacing at a fixed voltage.

Keywords


[1]   Kim, S.H., and Lee, K.W., “Experimental Study of Electrostatic Precipitator Performance and Comparison with Existing Theoretical Prediction Models”, J. Electrostatics Vol. 48, pp. 3-25, (1999).
 
[2]  Leonard, G., Mitchener, M., and Self, S. A., “An Experimental Study of the Electrohydrodynamics Flow in an Electrostatic Precipitators”, J. Fluid Mech. Vol. 127, pp. 123-140, (1983).
 
 
[4]  Laohalertdecha, S., Naphon, P., and Wongwises, S., “A Review of Electro Hydrodynamic Enhancement of Heat Transfer”, Renewable and Sustainable Energy Reviews, Vol. 11, pp. 858-876, (2007).
 
[5]  Brand, K., “Enhancement of External Condensation Heat Transfer with Electrohydrodynamic Induction Pumping”, Mechanical Engineering Department, Texas A&M University, Ph.D. Thesis, (2002).
 
]6[ پناهی، م. و عالم­رجبی، ع. " بررسی تجربی افزایش نسبت تبخیر آب با استفاده از الکترود سوزنی به روش الکتروهیدرودینامیکی"، نشریة پژوهشی مهندسی مکانیک ایران- سال سیزدهم، شماره اول، تابستان (1390).
 
[7] Sadek, H., Robinson, A.J., Cotton, J.S., Ching, C.Y., and Shoukri, M., “Electrohydrodynamic Enhancement of In-tube Convective Condensation Heat Transfer”, Int. J. Heat Mass Transfer, Vol. 49, pp. 1647–1657, (2006).
 
[8] Butrymowicz, D., Trela, M., and Karwacki, J., “Enhancement of Condensation Heat Transfer by Means of EHD Condensate Drainage”, Int. J. Therm. Sci., Vol. 41, pp. 646–657, (2002).
 
[9] Bologa, M.K., Savin, I.K., and Didkovsky, A.B., “Electric-field-induced Enhancement of Vapor Condensation Heat Transfer in the Presence of a Non-condensable Gas”, Int. J. Heat Mass Transfer, pp. 1558–1577, (1987).
 
[10] Bologa, M.K., and Didkovskiy, A.B., “Enhancement of Heat Transfer in Film Condensation of Vapors of Dielectric Liquids by Superposition of Electric Fields”, Heat Transfer Soviet Res., Vol. 9, pp. 147–151, (1997).
 
[11] Bologa, M.K., Savin, I.K., and Didkovsky, A.B., “Electric-field-induced Enhancement of Vapor Condensation Heat Transfer in the Presence of a Non-condensable Gas”, Int. J. Heat Mass Transfer, Vol. 30, pp. 1577–1585, (1987).
 
[12] Bologa, M. K., Sajin, T.M., Kozhukhar, L.A., Klimov, S.M., and Motorin, O.V., “The Influence of Electric Fields on Basic Processes Connected with Physical Phenomena in Two-phase Systems”, Int. Conference on Conduction and Breakdown in Dielectric Liquid, pp. 69–72, (1996).
 
[13] Cheung, K., Ohadi, M.M., and Dessiatoun, S.V., “EHD-assisted External Condensation of R-134a on Smooth Horizontal and Vertical Tubes”, Int. J. Heat Mass Transfer, Vol. 42, pp. 1747– 55, (1999).
 
[14] Holmes, R.E., and Chapman, A.J., “Condensation of Freon-114 in the Presence of a Strong Nounniform Alternating Electric Field”, J. Heat Transfer, pp. 616–20, (1970).
 
[15] Wawzyniak, M., and Seyed-Yagoobi, J., “Experimental Study of Electrohydro Dynamically Augmented Condensation Heat Transfer on a Smooth and an Enhanced Tube”, J. Heat Transfer, Vol. 118, pp. 499–502, (1996).
 
[16] Sunada, K., Yabe, A., Taketani, T., and Yoshizawa, Y., “Experimental Study of EHD Pseudo-drop Wise Condensation”, Proc. ASME/JSME Thermal Eng, Vol. 3, pp. 61–7, (1991).
 
[17] Moreau, E., Leger, L., and Touchard, G., “Effect of a DC Surface-corona Discharge on a Flat Plate Boundary Layer for Air Flow Velocity Up to 25 m/s”, J. Electrostatics, Vol. 64, pp. 215–225, (2006).
 
[18] Leonard, G., Mitchener, M., and Self, S. A., “An Experimental Study of the Electrohydrodynamics Flow in an Electrostatic Precipitators”, J. Fluid Mech. Vol. 127, pp. 123-140, (1983).
 
[19] Alemrajabi, A., and Lai, F. C., “EHD-enhanced Drying of Partially Wetted Glass Beads”, Drying Technology, Vol. 23, pp. 597–609, (2005).
 
[20] Laohalertdecha, S., and Wongwises, S., “Effects of EHD on Heat Transfer Enhancement and Pressure Drop During Two-phase Condensation of Pure R-134a at High Mass Flux in a Horizontal Micro-fin Tube”, Experimental Thermal and Fluid Science, Vol. 30, pp. 675–686, (2006).
 
[21] Kalman, H., and Sher, E., “Enhancement of Heat Transfer by Means of a Corona Wind Created by a Wire Electrode and Confined Wings Assembly”, Appl. Thermal Eng., Vol. 21, pp. 265-282, (2001).
 
[22] Kamkari, B., and Alemrajabi, A.A., “Investigation of Electrohydrodynamically Enhanced Convective Heat and Mass Transfer from Water Surface”, Int. J. Heat Transfer Engineering, pp. 138–146, (2010).
 
[23] Darabi, J., Ohadi, M.M., and Devoe, D., “An Electrohydrodynamic Polarization Micropump for Electronic Cooling”, J. Microelectromechanical Systems, Vol. 10, pp. 98–106, (2001).
 
[24] Barthakur, N.N., “Electrostatically Enhanced Evaporation Rates of Saline Water”, Desalination, Vol. 74, pp. 339-353, (1989).
 
]25[ پناهی، م.، " بررسی تجربی اثر شکل و هندسه الکترود بر نرخ تبخیرآب به روش الکتروهیدرودینامیکی (EHD)"، پایان­نامه کارشناسی ارشد، دانشگاه صنعتی اصفهان، دانشکده مکانیک،(1389).
 
[26] Lai, F.C., and Sharma, R.K., “EHD-enhanced Drying with Multiple Needle Electrode”, J. Electrostatics, Vol. 63, pp. 223–237, (2005).
 
[27] Subir, R., “An Introduction to High Voltage Engineering”, Prentice – Hall, New York, (2004)
 
[28] Kuffel, E., Zaengl, W. S., and Kuffel, J., “High Voltage Engineering: Fundamentals”, Newness, 2nd Edition, Published by Butterworth-Heinemann, (2000).
 
[29] Kibler, K. G., and Carter, H. G., “Electrocooling of Gases”, J. Applied Physics, Vol. 45, pp. 4436-4440, (1974).
 
[30] Chaker, M., and Cyrus, B., “Inlet Fogging of Gas Turbine Engines-part I: Fog Droplet Thermodynamics, Heat Transfer, and Practical Considerations”, J. Engineering for Gas Turbines and Power, Vol. 126, pp. 545-558, (2004).