Increase of COP for heat transformer in water purification systems. Part II – Without increasing heat source temperature

The integration of a water purification system allows a heat transformer to increase the actual coefficient of performance, by the reduction of the amount of heat supplied by unit of heat. A new defined COP called COPWP is proposed for the present system, which considers the fraction of heat recycled. Simulation with proven software compares the performance of the modeling of an absorption heat transformer for water purification (AHTWP) operating with water/lithium bromide, as working fluid–absorbent pair. Plots of enthalpy-based coefficients of performance (COPET) and water purification coefficient of performance (COPWP) are shown against absorber temperature for several thermodynamic operating conditions. The results showed that the proposed (AHTWP) system is capable of increasing the original value of COPET up to 1.6 times its original value by recycling energy from a water purification system. The proposed COPWP allows increments for COP values from any experimental data for water purification or for any other distillation system integrated to a heat transformer, regardless of actual COPA value or working fluid–absorbent pair.