Computer-aided design and test of new refrigerants for an absorption cycle using group contribution methods

The performance of refrigeration systems using absorption heat pumps depends mainly on the combination of two working fluids, i.e., the refrigerant and the absorbent. Consequently, this work presents a theoretical model for systematically testing pairs of absorbents and refrigerants with respect to key parameters such as the coefficient of performance (COP), the circulation ratio, etc. At this stage, the refrigerants considered were issued from combinations of a chosen set of functional groups, excluding the chlorine atom, for obvious reasons. The resulting compounds may or may not exist at all, but this does not prevent testing them theoretically. The absorbents were chosen as water or organic compounds commercially available. For the compound property estimation, the proposed technique is based on group contribution methods which have proven to be very suitable for this kind of problem, i.e., compound design. The method is very flexible, not costly in terms of computer time, and can be adapted to various situations. The results obtained are encouraging compared to some available experimental values reported in the literature.