Design of Experimental Rig for Validation of Absorption Power Cycle Concept

Abstract Absorption power cycles (APC) are an interesting concept of heat engines especially in the domain of low temperature waste heat recovery. It uses a multicomponent working fluid which enables boiling and condensation to take place with a temperature glide instead of isothermal process for single-component fluid, which can serve to increase the exergy efficiency of heat exchangers. Absorption process has also an effect of lowering exhaust pressure of a turbine. Among absorption power cycles nearly all of commercial, experimental and theoretical concepts use water-ammonia mixture as a working fluid. Only very few and mostly recent works are starting to look at other working fluids with specific interest and potential in using LiBr aqueous solution known from absorption cooling. Concept of such cycle has both thermodynamic and environmental benefits; however it brings many challenges that need to be resolved. Among them stands out an experimental validation of actual temperature profile in variable-temperature phase-change heat exchangers. Another major issue for a LiBr system is also purity of the steam going to the expander. Therefore in this work is proposed an experimental rig for validation of these assumptions. Particularly the temperature profile will be investigated within an experimental desorber, purity of steam leaving two phase separator will be analysed to set up design limits for the expander. Next phase will add experimental absorber and expander emulator. Focus will be given on modular approach and possibility to test different equipment designs.