HCFC22-based vapour absorption refrigeration systems. Part II: Influence of component effectiveness

A thermodynamic analysis was performed on a single-stage vapour absorption refrigeration system (VARS) operating with monochlorodifluouromethane (HCFC22) as a refrigerant and dimethylether of tetraethyleneglycol (DMETEG) or dimethyl acitamide (DMA) as a working fluid. Influence of solution heat exchanger effectiveness (Eh) and mass transfer effectivenesses of absorber (Eg) and generator (Es) on the performance of VARS were studied. The variations in heat quantities at solution heat exchanger, generator and absorber as well as performance characteristics, namely CR, COPth and second law efficiency (ε) at various operating temperatures are reported. As expected, low CR and high COPth and ε can be obtained at high values of Eh, Ea and Eg. The effects of Eh on the performance is more pronounced when compared to that of Ea and Eg. Also, the change in the circulation ratio (CR) due to a given change in Ea is higher than that due to the same change in Eg. CR is not a function of Eh. A comparison of the influence of Eh, Ea, and Eg on the VARS performance for HCFC22-DMA and HCFC22-DMETEG pairs was made.