Performance of air-cooled absorption air-conditioning systems working with water-(LiBr plus LiI+LiNO3+LiCl)

The potential of the fluid mixture water-(LiBr+LiI+LiNO3+LiCl) (5:1:1:2 molar) is studied for air-cooled absorption air-conditioning systems. This multicomponent system shows a considerably higher solubility than that of water-LiBr and is also less corrosive. It is, therefore, one of the potential alternatives to replace water-LiBr in future air-cooled absorption chillers. A comparative study based on thermodynamic simulation of the single- and double-effect cycles with water-LiBr and the new fluid mixture is first reported. Once the operating conditions were established in terms of temperature and concentration in the generator and the absorber, the absorption process of a falling film flowing on the inner surface of a vertical tube at typical air cooling thermal operating conditions of the absorber was modelled in order to compare the absorption rates of the multicomponent salt mixture with those of water-LiBr. This study was completed by an experimental characterization of the absorption process in a vertical falling film tube. The results show that the multicomponent salt solution is more suitable than water-LiBr if the temperatures in the generator and absorber/condenser are low and high, respectively. Therefore this new working fluid can be recommended for air-cooled absorption air-conditioning systems driven by low temperature heat sources.