Performance analysis of a liquid desiccant and membrane contactor hybrid air-conditioning system

Abstract The present study examines the performances of a hybrid air-conditioning system in which a vapour-compression inverse cycle is integrated with an air dehumidification system working with hygroscopic solution and hydrophobic membrane. This model may be a valid alternative to traditional summertime air-conditioning system, in which the air is cooled to below its dew-point temperature and subsequently reheated. The proposed hybrid system involves simultaneously cooling and dehumidifying the air conveyed to the conditioned ambient in an air-solution membrane contactor. An LiCl solution is cooled by means of a vapour-compression inverse cycle using the refrigerant KLEA 407C. The solution is regenerated in another membrane contactor by exploiting the heat rejected by the condenser. A SIMULINK calculation programme was designed in order to simulate the system under examination in steady-state conditions. The performances of the system were analysed on varying a few significant operating parameters, and were compared with those of a traditional direct-expansion air-conditioning plant in typical summertime conditions. The results of the simulations revealed significant energy savings, which, in particular operating conditions, may exceed 50%.

[1]  E F JOHNSON,et al.  Thermodynamic properties of aqueous lithium chloride solutions; an evaluation of the gas current method for the determination of the thermodynamic properties of aqueous salt solutions. , 1951, The Journal of physical and colloid chemistry.

[2]  Ruzhu Wang,et al.  Use of liquid desiccant cooling to improve the performance of vapor compression air conditioning , 2001 .

[3]  V. Teplyakov,et al.  Membrane contactor air conditioning system: Experience and prospects , 2007 .

[4]  Klaus-Viktor Peinemann,et al.  Hollow fiber membrane contactor for air humidity control: Modules and membranes , 2006 .

[5]  J. E. Janssen,et al.  Ventilation for acceptable indoor air quality , 1989 .

[6]  Clito Afonso,et al.  Recent advances in building air conditioning systems , 2006 .

[7]  S. C. Kaushik,et al.  Thermodynamic design and assessment of hybrid double absorption solar cooling systems , 1991 .

[8]  Geert Versteeg,et al.  Modelling of cross-flow membrane contactors: physical mass transfer processes , 2005 .

[9]  Y. K. Yadav.  Vapour-compression and liquid-desiccant hybrid solar space-conditioning system for energy conservation , 1995 .

[10]  R. Shah,et al.  Handbook of single-phase convective heat transfer , 1987 .

[11]  Anthony G. Fane,et al.  Gas and vapour transport through microporous membranes. I. Knudsen-Poiseuille transition , 1990 .

[12]  Anna Chiari,et al.  Vapour Compression and Liquid Desiccant Hybrid System for Air Conditioning , 2006 .

[13]  Abdulghani A. Al-Farayedhi,et al.  Simulation of a hybrid liquid desiccant based air-conditioning system , 1997 .

[14]  Pradeep Bansal,et al.  Performance analysis of liquid desiccant dehumidification systems , 2007 .

[15]  Renato Lazzarin.  La deumidificazione chimica fra teoria e pratica , 2002 .

[16]  Francesco Minichiello,et al.  HVAC dehumidification systems for thermal comfort: a critical review , 2005 .

[17]  S. C. Kaushik,et al.  Psychometric technoeconomic assessment and parametric studies of vapor-compression and solid/liquid desiccant hybrid solar space conditioning systems , 1991 .

[18]  Anna Magrini,et al.  On the application of a membrane air—liquid contactor for air dehumidification , 1997 .

[19]  P. L. Dhar,et al.  Studies on solid desiccant based hybrid air-conditioning systems , 2001 .

[20]  Drew W. Johnson,et al.  Analysis of heat and mass transfer phenomena in hollow fiber membranes used for evaporative cooling , 2003 .

[21]  Farid Nasir Ani,et al.  The Effect of Absorber Packing Height on the Performance of a Hybrid Liquid Desiccant System , 2005 .

[22]  A. Chiari.  Air humidification with membrane contactors: experimental and theoretical results , 2000 .

[23]  S. Bergero,et al.  Experimental and theoretical analysis of air humidification/dehumidification processes using hydrophobic capillary contactors , 2001 .

[24]  Ruzhu Wang,et al.  Analysis on a hybrid desiccant air-conditioning system , 2006 .

[25]  Chaobin Dang,et al.  Performance analysis of a no-frost hybrid air conditioning system with integrated liquid desiccant dehumidification , 2010 .

[26]  L. Mei,et al.  A technical review on use of liquid-desiccant dehumidification for air-conditioning application , 2008 .

[27]  Shaligram Tiwari,et al.  Performance characterisation of liquid desiccant columns for a hybrid air-conditioner , 2008 .