Experimental assessment of double-absorption heat transformer operating with H2O/LiBr

Highlights: • A double-absorption heat transformer was developed operating with H₂O/LiBr. • Gross temperature lifts as high as 74 °C were achieved with the system. • The gross temperature lifts are the highest reported in the literature using H₂O/LiBr. • Up to 37% of the energy supplied to the DAHT could be retrieved at higher temperature levels. - Abstract: This paper reports on the experimental results of a double-absorption heat transformer operating with a H₂O/LiBr mixture. The generator and evaporator are pool boiling type heat exchangers, while the remaining components are coils inside shells. Plots of gross temperature lifts, economizer efficiency, and internal and external performance coefficients are reported as functions of diverse operating parameters of the heat transformer. The results indicate that the system can achieve gross temperature lifts (GTLs) of between 48 °C and 74 °C, with internal performance coefficients varying from 0.12 to 0.37. The GTLs achieved are up to 30 °C higher than those reported in the literature, using a single-stage heat transformer operating with the same working mixture. Furthermore, the system exhibits effective stability and repeatability.