Document Type : Full article


1 Department of Chemistry, Islamic Azad University, Chalus Branch, P.O. Box 46615-397, Iran

2 Faculty of Chemical Engineering, Tarbiat Modares University, Tehran, P.O. Box 14155-143, Iran


This study introduces an experimental and theoretical investigation of the performance of a proposed air dehumidification system using a nanofluid of γ-alumina nano-particles in LiBr/H2O as a desiccant. Comparative experiments organized using a central composite design were carried out to evaluate the effects of six numerical factors (air velocity, desiccant flow rate, air humidity ratio, desiccant solution concentration, air temperature, desiccant temperature) and one categorical factor (adding nano-particles) on outlet air humidity ratio and outlet air temperature as responses. Reduced quadratic models were derived for each response. The results revealed that the concentration of LiBr/H2O solution and air temperature had the largest effect on outlet air humidity ratio and outlet air temperature, respectively. It was found that the average increase in mass transfer rate was 12.23% and heat transfer rate was 13.22% when γ-alumina nano-particles (0.02% wt) were added to the LiBr/H2O solution. The average increase in mass transfer coefficient was 22.73% and heat transfer coefficient was 26.51%.


Main Subjects

[1]      Fumo, N. and Goswami, D.Y., “Study of an aqueous lithium chloride desiccant system: Air dehumidification and desiccant regeneration”, Solar Energy, 72, 351(2002).
[2]      Gandhidasan, P., “A simplified model for air dehumidification with liquid desiccant”, Solar Energy, 76, 409 (2004).
[3]      Hassan, A.A.M. and Salah Hassan, M., “Dehumidification of air with a newly suggested liquid desiccant”, Renew. Energy., 33, 1989 (2008).
[4]      Li, X.W., Zhang, X.S., Wang, G. and Cao, R.G., “Research on ratio selection of a mixed liquid desiccant: Mixed LiCl–CaCl2 solution”, Solar Energy, 82, 1161 (2008).
[5]      Pahlavanzadeh, H. and Nooriasl, P., “Experimental and theoretical study of liquid desiccant dehumidification system by using the effectiveness model”, J. Therm. Sci. Eng. Appl., 4, 1 (2012) .
[6]      Moon, C.G., Bansal, P.K., and Jain, S., “New mass transfer performance data of a cross-flow liquid desiccant dehumidification system”, Int. J. Refrig., 32, 524 (2009).
[7]      Longo, G.A. and Gasparella, A., “Experimental and theoretical analysis of heat and mass transfer in a packed column dehumidifier/regenerator with liquid desiccant”, Int. J. Heat. Mass Transf., 48, 5240 (2005).
[8]      Omidvar Langroudi, L. and Palavanzadeh, H., “Statistical investigation of air dehumidification performance by aqueous lithium bromide desiccant in a packed column: A thermodynamic approach”, J. Therm. Sci. Eng. Appl., 7, 041013 (2015).
[9]      Ren, C.Q., “Corrections to the simple effectiveness-NTU method for counterflow cooling towers and packed bed liquid desiccant–air contact systems”, Int. J. Heat. Mass Transf., 51, 237 (2008).
[10]  Liu, X.H. and Jiang, Y., “Coupled heat and mass transfer characteristic in packed bed dehumidifier/regenerator using liquid desiccant”, Energy Convers. Manage., 49, 1357 (2008).
[11]  Luo, Y., Yang, H., Lu, L., and Qi, R., “A review of the mathematical models for predicting the heat and mass transfer process in the liquid desiccant dehumidifier”, Renew. Sustain. Energy Reviews., 31, 587 (2014).
[12]  Koronaki, I.P., Christodoulaki, R.I., Papaefthimiou, V.D., and Rogdakis, E.D., “Thermodynamic analysis of a counter flow adiabatic dehumidifier with different liquid desiccant materials”, Appl. Therm. Eng., 50, 361 (2013).
[13]  Omidvar Langroudi, L., Palavanzadeh, H. and Mousavi, S.M.,  “Statistical evaluation of a liquid desiccant dehumidification system using RSM and theoretical study based on the effectiveness NTU model”, J. Indust. Eng. Chem., 20, 2975 (2014).
[14]  Dai, Y.J., Wang, R. Z.,  Zhang, H. F. and Yu, J.D.,  “Use of liquid desiccant cooling to improve the performance of vapor compression air conditioning”, Appl. Therm. Eng., 21, 1185 (2001).
[15]  Li, Z., Liu, X.H., Jiang, Y. and Chen, X.Y., “New type of fresh air processor with liquid desiccant total heat recovery”, Energy Build, 37, 587 (2005).
[16]  Bassuoni, M.M., “Experimental performance study of a proposed desiccant based air conditioning system”, J. Advanced Res., 5, 87 (2014).
[17]  Wang, X.Q. and Mujumdar, A.S., “Heat transfer characteristics of nanofluids: A review”, Int. J. Therm. Sci., 46, 1 (2007).
[18]  Yang, L., Du, K.,  Niu, X.F.,  Cheng, B. and Jiang, Y.F., “Experimental study on enhancement of ammonia-water falling film absorption by adding nano-particles”, Int. J. Refrig., 34, 640 (2011).
[19]  Zamzamian, A., Nasseri Oskouie, S., Doosthoseini, A., Joneidi, A. and Pazouki, M., “Experimental investigation of forced convective heat transfer coefficient in nanofluids of Al2O3/EG and CuO/EG in a double pipe and plate heat exchangers under turbulent flow”, Exp. Therm. Fluid Sci., 35, 495 (2011).  
[20]  Murshed, S.M.S., Leong, K.C., and Yang, C., “Enhanced thermal conductivity of TiO2-water based nanofluids”, Int. J. Therm. Sci., 44, 367 (2005).
[21]  Wen, D. and Ding, Y., “Experimental investigation into convective heat transfer of nanofluids at the entrance region under laminar flow conditions”, Int. J. Heat. Mass Transf., 47, 5181 (2004).
[22]  Kakac, S. and Pramuanjaroenkij, A., “Review of convective heat transfer enhancement with nanofluids”, Int. J. Heat. Mass Transf., 52, 3187 (2009).
[23]  Fang, X., Xuan, Y. and Li, Q., “Experimental investigation on enhanced mass transfer in nanofluids”, Appl. Physics Letters., 95, 203108 (2009).
[24]  Feng, X. and Johnson, D.W., “Mass transfer in SiO2 nanofluids: A case against purported nanoparticle convection effects”, Int. J. Heat. Mass Transf., 55, 3447 (2012).
[25]  Zhu, H., Shanks, B.H. and Heindel, J.J., “Enhancing Co-water mass transfer by functionalized MCM41 nanoparticles”, Ind. Eng. Chem. Res., 47, 7881 (2008).
[26]  Kang, Y.T., Kim, H.J., and Lee, K.I., “Heat and mass transfer enhancement of binary nanofluids for H2O/LiBr falling film absorption process”, Int. J. Refrig., 31, 850 (2008).
[27]  Kim, H., Jeong, J. and Tae Kang, Y., “Heat and mass transfer enhancement for falling film absorption process by SiO2 binary nanofluids”, Int. J. Refrig., 35, 645 (2012).
[28]  Yin, Y. and Zhang, X., “A new method for determining coupled heat and mass transfer coefficients between air and liquid desiccant”, Int. J. Heat. Mass Transf., 51, 3287 (2008).
[29]  Zhao-qiang, Z., Hong-ying, X., Srinivasakannan, C., Jin-hui, P. and Li-bo, Z., “Utilization of Crofton weed for preparation of activated carbon by
microwave induced CO2 activation”, Chem. Eng. Process., 82, 1 (2014).
[30]  Jalilian Nosrati, H., Aishah Saidina Amin, N., Talebian-Kiakalaieh, A. and Noshadi, I., “Microwave assisted biodiesel production from Jatropha curcas L. seed by two-step in situ process: Optimization using response surface methodology”, Bioresource Tech., 136, 565 (2013).
[31]  Montgomery, D.C., Design and analysis of experiments, John Wiley & Sons, New York, (2001).
[32]  Khuri, A.I. and Comell, J.A.,  Response Surface: Design and analysis, Marcel Dekker, New York, (1987).
[33]  Amani, T., Nosrati, M.,  Mousavi, S.M.,  and Kermanshahi, R.K., “Study of syntrophic anaerobic digestion of volatile fatty acids using enriched cultures at mesophilic conditions”,  Int. J. Environ. Sci. and Tech., 8(1), 83 (2011).
[34]  Zangeneh, H., Zinatizadeh, A.A.L.,  and Feizy, M., “A comparative study on the performance of different advanced oxidation processes (UV/O3/H2O2) treating linear alkyl benzene (LAB) production plant’s wastewater”, J. Indust. Eng. Chem., 20, 1453 (2014) .