Ammonia-water absorption cycle: heat transformer and hybrid reversible design to upgrade excess heat and produce power
Decarbonization of the industrial sector is a major challenge to reduce global greenhouse gas emissions. 36% of the industrial energy consumption is lost in the form of excess heat, with about 25% being between 40 and 100°C; therefore, the implementation of efficient thermodynamic cycles to recover energy from this heat is appealing. Ammonia-water absorption heat transformers (AHT) can upgrade industrial excess heat (~ 80°C) to higher temperature (> 100°C) suitable to run industrial processes. The valuable output of such cycle design is the heat released by the absorber. This work presents the experimental insights of a 10 kW NH3-H2O AHT prototype. Notably, complex dependencies of the components and the challenging operating conditions limit the performance. Another significant perspective of industrial excess heat recovery is power production. Thus, the present study introduces an innovative hybrid reversible design allowing for either upgrading excess heat temperature level or generate electricity. The energy outputs of this versatile cycle might serve internal industrial applications or integrate external power supply grid.