Hybrid thermochemical cycles for power and cold cogeneration: thermodynamic analysis and dynamic performances

Based on the coupling of a thermochemical sorption cycle with an expansion device, five operating modes are presented for low-grade heat storage and conversion into power and cold. Considering CaCl2,(8/4)NH3 as reactant, the performances of these hybrid cycles are presented. The simultaneous power and cold production mode is the most promising one. Its energy and exergy efficiencies reach 0.50 and 0.33, respectively, and its energy storage density 151.4 kWh/m3 system. The study of the dynamic behavior of this cycle shows that a suitable control of the expander leads to stable power and cold outputs of 490 W and 8 kW for 3 hours, using 0.19 m3 reactive composite.