Influence of generator effectiveness on performance of vapour absorption heat transformers

The effects of mass transfer effectiveness of absorber on the performance of single stage vapour absorption heat transformers were studied by making a thermodynamic analysis. The refrigerant absorbent pairs considered were R21-DMF and R21-DMETEG. The variations in performance parameters such as coefficient of performance, exergetic efficiency, concentration difference and circulation ratio with mass transfer effectiveness of the absorber at various operating temperatures were computed. Increasing the effectiveness of absorber resulted in increases in coefficient of performance, exergetic efficiency and concentration differential across the absorber. The improvements in coefficient of performance and exergetic efficiency with mass transfer effectivensss of the absorber were more pronounced for the R21-DMF pair than for R21-DMETEG. Correlations are presented for quick estimation of performance under different operating conditions.